Download Hi-Res ImageDownload to MS-PowerPointCite This:Environ. Sci. Technol. Lett. 2020, 7, 11, 809-818
This publication is Open Access under the license indicated. Learn More
Anthropogenic Impacts on the Atmosphere
Unprecedented Ambient Sulfur Trioxide (SO3) Detection: Possible Formation Mechanism and Atmospheric ImplicationsClick to copy article linkArticle link copied!
- Lei YaoLei YaoAerosol and Haze Laboratory, Beijing Advanced Innovation Center for Soft Matter Science and Engineering, Beijing University of Chemical Technology, Beijing 100089, ChinaInstitute for Atmospheric and Earth System Research/Physics, Faculty of Science, University of Helsinki, Helsinki 00560, FinlandMore by Lei Yao
- Xiaolong FanXiaolong FanAerosol and Haze Laboratory, Beijing Advanced Innovation Center for Soft Matter Science and Engineering, Beijing University of Chemical Technology, Beijing 100089, ChinaMore by Xiaolong Fan
- Chao YanChao YanInstitute for Atmospheric and Earth System Research/Physics, Faculty of Science, University of Helsinki, Helsinki 00560, FinlandMore by Chao Yan
- Theo KurténTheo KurténDepartment of Chemistry, University of Helsinki, Helsinki 00014, FinlandMore by Theo Kurtén
- Kaspar R. DaellenbachKaspar R. DaellenbachInstitute for Atmospheric and Earth System Research/Physics, Faculty of Science, University of Helsinki, Helsinki 00560, FinlandMore by Kaspar R. Daellenbach
- Chang LiChang LiAerosol and Haze Laboratory, Beijing Advanced Innovation Center for Soft Matter Science and Engineering, Beijing University of Chemical Technology, Beijing 100089, ChinaMore by Chang Li
- Yonghong WangYonghong WangInstitute for Atmospheric and Earth System Research/Physics, Faculty of Science, University of Helsinki, Helsinki 00560, FinlandMore by Yonghong Wang
- Yishuo GuoYishuo GuoAerosol and Haze Laboratory, Beijing Advanced Innovation Center for Soft Matter Science and Engineering, Beijing University of Chemical Technology, Beijing 100089, ChinaMore by Yishuo Guo
- Lubna DadaLubna DadaInstitute for Atmospheric and Earth System Research/Physics, Faculty of Science, University of Helsinki, Helsinki 00560, FinlandMore by Lubna Dada
- Matti P. RissanenMatti P. RissanenAerosol Physics Laboratory, Physics Unit, Tampere University, Tampere 33100, FinlandMore by Matti P. Rissanen
- Jing CaiJing CaiInstitute for Atmospheric and Earth System Research/Physics, Faculty of Science, University of Helsinki, Helsinki 00560, FinlandMore by Jing Cai
- Yee Jun ThamYee Jun ThamInstitute for Atmospheric and Earth System Research/Physics, Faculty of Science, University of Helsinki, Helsinki 00560, FinlandMore by Yee Jun Tham
- Qiaozhi ZhaQiaozhi ZhaInstitute for Atmospheric and Earth System Research/Physics, Faculty of Science, University of Helsinki, Helsinki 00560, FinlandMore by Qiaozhi Zha
- Shaojun ZhangShaojun ZhangState Key Joint Laboratory of Environment Simulation and Pollution Control, State Environmental Protection Key Laboratory of Sources and Control of Air Pollution Complex, School of Environment, Tsinghua University, Beijing 100084, ChinaMore by Shaojun Zhang
- Wei DuWei DuInstitute for Atmospheric and Earth System Research/Physics, Faculty of Science, University of Helsinki, Helsinki 00560, FinlandMore by Wei Du
- Miao YuMiao YuInstitute of Urban Meteorology, China Meteorological Administration, Beijing 100081, ChinaMore by Miao Yu
- Feixue ZhengFeixue ZhengAerosol and Haze Laboratory, Beijing Advanced Innovation Center for Soft Matter Science and Engineering, Beijing University of Chemical Technology, Beijing 100089, ChinaMore by Feixue Zheng
- Ying ZhouYing ZhouAerosol and Haze Laboratory, Beijing Advanced Innovation Center for Soft Matter Science and Engineering, Beijing University of Chemical Technology, Beijing 100089, ChinaMore by Ying Zhou
- Jenni KontkanenJenni KontkanenInstitute for Atmospheric and Earth System Research/Physics, Faculty of Science, University of Helsinki, Helsinki 00560, FinlandMore by Jenni Kontkanen
- Tommy ChanTommy ChanInstitute for Atmospheric and Earth System Research/Physics, Faculty of Science, University of Helsinki, Helsinki 00560, FinlandMore by Tommy Chan
- Jiali ShenJiali ShenInstitute for Atmospheric and Earth System Research/Physics, Faculty of Science, University of Helsinki, Helsinki 00560, FinlandMore by Jiali Shen
- Joni T. KujansuuJoni T. KujansuuAerosol and Haze Laboratory, Beijing Advanced Innovation Center for Soft Matter Science and Engineering, Beijing University of Chemical Technology, Beijing 100089, ChinaInstitute for Atmospheric and Earth System Research/Physics, Faculty of Science, University of Helsinki, Helsinki 00560, FinlandMore by Joni T. Kujansuu
- Juha KangasluomaJuha KangasluomaAerosol and Haze Laboratory, Beijing Advanced Innovation Center for Soft Matter Science and Engineering, Beijing University of Chemical Technology, Beijing 100089, ChinaInstitute for Atmospheric and Earth System Research/Physics, Faculty of Science, University of Helsinki, Helsinki 00560, FinlandMore by Juha Kangasluoma
- Jingkun JiangJingkun JiangState Key Joint Laboratory of Environment Simulation and Pollution Control, State Environmental Protection Key Laboratory of Sources and Control of Air Pollution Complex, School of Environment, Tsinghua University, Beijing 100084, ChinaMore by Jingkun Jiang
- Lin WangLin WangShanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP3), Department of Environmental Science & Engineering, Fudan University, Shanghai 200438, ChinaMore by Lin Wang
- Douglas R. WorsnopDouglas R. WorsnopAerodyne Research Inc., Billerica, Massachusetts 01821, United StatesMore by Douglas R. Worsnop
- Tuukka PetäjäTuukka PetäjäInstitute for Atmospheric and Earth System Research/Physics, Faculty of Science, University of Helsinki, Helsinki 00560, FinlandMore by Tuukka Petäjä
- Veli-Matti KerminenVeli-Matti KerminenInstitute for Atmospheric and Earth System Research/Physics, Faculty of Science, University of Helsinki, Helsinki 00560, FinlandMore by Veli-Matti Kerminen
- Yongchun LiuYongchun LiuAerosol and Haze Laboratory, Beijing Advanced Innovation Center for Soft Matter Science and Engineering, Beijing University of Chemical Technology, Beijing 100089, ChinaMore by Yongchun Liu
- Biwu ChuBiwu ChuInstitute for Atmospheric and Earth System Research/Physics, Faculty of Science, University of Helsinki, Helsinki 00560, FinlandState Key Joint Laboratory of Environment Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, ChinaCenter for Excellence in Regional Atmospheric Environment, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, ChinaMore by Biwu Chu
- Hong He*Hong He*Email: [email protected]State Key Joint Laboratory of Environment Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, ChinaCenter for Excellence in Regional Atmospheric Environment, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, ChinaMore by Hong He
- Markku Kulmala*Markku Kulmala*Email: [email protected]Aerosol and Haze Laboratory, Beijing Advanced Innovation Center for Soft Matter Science and Engineering, Beijing University of Chemical Technology, Beijing 100089, ChinaInstitute for Atmospheric and Earth System Research/Physics, Faculty of Science, University of Helsinki, Helsinki 00560, FinlandJoint International Research Laboratory of Atmospheric and Earth System Sciences (JirLATEST), Nanjing University, Nanjing 210023, ChinaMore by Markku Kulmala
- Federico Bianchi*Federico Bianchi*Email: [email protected]Aerosol and Haze Laboratory, Beijing Advanced Innovation Center for Soft Matter Science and Engineering, Beijing University of Chemical Technology, Beijing 100089, ChinaInstitute for Atmospheric and Earth System Research/Physics, Faculty of Science, University of Helsinki, Helsinki 00560, FinlandMore by Federico Bianchi
Abstract
Click to copy section linkSection link copied!
Sulfur trioxide (SO3) is a crucial compound for atmospheric sulfuric acid (H2SO4) formation, acid rain formation, and other atmospheric physicochemical processes. During the daytime, SO3 is mainly produced from the photo-oxidation of SO2 by OH radicals. However, the sources of SO3 during the early morning and night, when OH radicals are scarce, are not fully understood. We report results from two field measurements in urban Beijing during winter and summer 2019, using a nitrate-CI-APi-LTOF (chemical ionization-atmospheric pressure interface-long-time-of-flight) mass spectrometer to detect atmospheric SO3 and H2SO4. Our results show the level of SO3 was higher during the winter than during the summer, with high SO3 levels observed especially during the early morning (∼05:00 to ∼08:30) and night (∼18:00 to ∼05:00 the next day). On the basis of analysis of SO2, NOx, black carbon, traffic flow, and atmospheric ions, we suggest SO3 could be formed from the catalytic oxidation of SO2 on the surface of traffic-related black carbon. This previously unidentified SO3 source results in significant H2SO4 formation in the early morning and thus promotes sub-2.5 nm particle formation. These findings will help in understanding urban SO3 and formulating policies to mitigate secondary particle formation in Chinese megacities.
Copyright © 2020 American Chemical Society
Introduction
Click to copy section linkSection link copied!
Atmospheric SO3 is a vital intermediate in gaseous H2SO4 formation, which in turn is a crucial compound in acid rain formation, new particle formation, secondary aerosol formation, and other atmospheric physicochemical processes. (1−8) During the daytime, when the intensity of UVB (ultraviolet radiation B) radiation that leads to the formation of OH radicals is high, SO3 is mainly formed by atmospheric photo-oxidation of SO2 by OH radicals. The mechanism of formation of SO3 from photo-oxidation can be written as
(R1)
(R2)
However, during the early morning and at night, when OH radicals are scarce, the sources of atmospheric SO3 remain unclear. Stabilized Criegee intermediates (sCI; general formula of R1R2COO) generated from the ozonolysis of alkenes have been found to be an important gas-phase oxidant for SO2 in addition to OH (eq R3): (9,10)
(R3)
Besides gas-phase oxidation of SO2 by OH radicals and sCI, SO3 may also be formed from the heterogeneous oxidation of SO2 on oxygen-functionalized graphene and soot surfaces. (11−13) He et al. have proposed that SO2 molecules can react with surface epoxide groups of carbonaceous (or soot) aerosols, leading to SO3 formation. These surface epoxy groups are considerably enhanced by atmospheric aging of soot particles in the presence of O2. (12,14) Additionally, a recent theoretical study revealed high atmospheric water content could promote the oxidation of SO2 to SO3 by O2 on carbonaceous aerosol surfaces. (15) Although extensive laboratory studies have reported that persistent particulate H2SO4 and sulfate can be formed from catalytic heterogeneous reaction between SO2 and carbon (soot) particles in the presence of O2, O3, NOx, NH3, and water, (16−19) the intermediate precursors of particulate sulfate, and the molecular-level details of this process, remain unclear. In addition to atmospheric formation of SO3 via the oxidation of SO2, a large amount of SO3 can also be emitted to the air from coal-fired power plants and other industrial processes related to coal combustion and then be rapidly converted to H2SO4. (20−22)
In the atmosphere, the water-catalyzed hydration of SO3 plays an essential role in H2SO4 formation (eq R4).
(R4)
In reaction R4, the second water molecule acts as a catalyst and significantly reduces the energy barrier of SO3 hydration. (23,24) The rate coefficient of the reaction of SO3 with the water dimer [(H2O)2], or H2O-catalyzed hydrolysis, is between 10–12 and 10–10 cm3 molecule–1 s–1, resulting in a very short lifetime (<1 s) of SO3. (23−26) In the atmosphere, besides water-catalyzed hydration, ammonia, sulfuric acid, formic acid, nitric acid, and oxalic acid (among others) can also act as catalysts for the SO3 hydration process and thus facilitate H2SO4 formation. (25,27−29)
The detection of SO3 is challenging owing to its high reactivity with water in ambient air. Various measurement technologies have been utilized for SO3 detection in flue gases, including the controlled condensation method, absorption by isopropyl alcohol, selective reaction method with calcium oxalate, and spectroscopy and mass spectrometry methods. (22,30) The detection limits of these methods are unfortunately too high to measure trace-level SO3 in ambient air. In some laboratory studies, the ions SiF5–, SF6–, NO3–·HNO3, and n-C3H7NH3+ have been used as reagent ions to detect SO3. (31−35)
In this study, we deployed a nitrate-chemical ionization-atmospheric pressure interface-long-time-of-flight (nitrate-CI-APi-LTOF) mass spectrometer in two field measurements for atmospheric SO3 and H2SO4 during the winter from January 20 to March 31 and during the summer from June 1 to July 10, 2019, in urban Beijing. This paper presents, for the first time, the trace-level measurement of gaseous SO3 by a nitrate-CI-APi-LTOF mass spectrometer in an urban atmosphere. Additionally, atmospheric naturally charged ions were also measured from November 9 to 22, 2018. Combining the SO3 measurements with data on trace gases, black carbon (BC), traffic flow, and atmospheric ions, we suggest a possible mechanism of formation of SO3 in urban Beijing. We also probe the effects of SO3 on atmospheric H2SO4 and sub-2.5 nm particle formation.
Materials and Methods
Click to copy section linkSection link copied!
Detection of SO3 and H2SO4 by a Nitrate-CI-APi-LTOF Mass Spectrometer
The working principle of the nitrate-CI-APi-LTOF mass spectrometer is described in Text S2 and many other studies. (5,36) The high-resolution peak fit of SO3·(NO3–) and its isotope peak [34SO3·(NO3–)] are depicted in Figure S1. The nitrate-CI-APi-LTOF mass spectrometer was calibrated by in situ-generated SO3 and H2SO4 (37) (Text S4). The calibration coefficients for SO3 and H2SO4 are determined to be 1.7 × 1010 and 6.1 × 109 cm–3, respectively (Figure S4). The ratio between the calibration coefficients of SO3 and H2SO4 is 2.8, which is consistent with the theoretical prediction of a difference of a factor of 3 in the charging efficiency (Text S5). On the basis of repeat experiments, the 1σ of the SO3 calibration coefficient was ±10%.
According to our quantum chemical calculation for the binding thermodynamics of SO3·(NO3–) and HNO3·(NO3–) ion–molecule clusters, the electronic binding energy of SO3·(NO3–) is −44.4 kcal/mol, which is substantially higher than that of HNO3·(NO3–) (−29.2 kcal/mol) (Texts S6 and S7 and Table S1). Thus, SO3 molecules can be efficiently charged by nitrate ions. The highly favorable ligand exchange reaction between neutral SO3 molecules and nitrate ions can be written as
(R5)
Furthermore, on the basis of the quantum chemical calculation, reaction R6 is exothermal by 8.7 kcal/mol in free energy (Text S6). The lowest-free energy structure for SO3·(NO3–)·H2O is depicted in Figure S6. Therefore, the hydrate complex intermediate (SO3·H2O) also can be detected as SO3·(NO3–).
(R6)
Besides the ligand exchange reaction, the reaction between SO3 and NO3– can also lead to SO4– formation (eq R7). (32) However, SO4– can also be produced by the reaction of SO2 with O2–·(H2O)n. (34,38) From our ambient data, the averaged ratios of SO4– to SO3·(NO3–) were 0.26 ± 0.07 (winter) and 2.51 ± 2.60 (summer). During the summer, a large abundance of O2–·(H2O)n favored SO4– formation. Hence, only the signal of SO3·(NO3–) was taken into account in the SO3 quantification, and it could cause a slight underestimation of SO3 concentrations.
(R7)
Atmospheric ions were also measured with the CI-APi-LTOF mass spectrometer by turning off the chemical ionization unit. Details of other auxiliary measuring instruments for trace gases, BC, meteorological parameters, and sub-3 nm particles can be found in Texts S8 and S9. Also, the calculation of condensation sink (CS) and quantification of SO3 and H2SO4 were introduced in Texts S10 and S3.
Results and Discussion
Click to copy section linkSection link copied!
Abundance and Diurnal Behavior of SO3 in the Winter and Summer
As shown in Figure 1A, the abundance of SO3 was significantly higher in the winter than in the summer. During the winter, the mixing ratios of SO3 varied from ∼4.0 × 104 to 1.9 × 106 molecules cm–3. In comparison, during the summer, SO3 concentrations ranged from ∼5.0 × 103 to 1.4 × 105 molecules cm–3. Under 298 K and 1 atm, the atmospheric SO3 concentration has been proposed to reach 105 molecules cm–3 around noon. (25) In this study, because the influence of ambient ions (i.e., SO3·NO3–) was not excluded and the hydrate complex intermediate (SO3·H2O) also could be detected as SO3·NO3– (eq R6), SO3 concentrations could be overestimated. Median diurnal variations of SO3 and SO2 concentrations, water dimer concentrations [(H2O)2; computed from the relative humidity and temperature], (26,39) and intensities of UVB (280–315 nm) on all measurement days during the winter and summer are illustrated in Figure 1B. The water dimer concentration during the summer was notably higher than during the winter. In contrast, the mixing ratio of SO2 during the summer was lower than that during the winter. In the atmosphere, due to the large abundance of water, it is generally accepted that hydration to H2SO4 is the main fate of SO3. (24) As a second water molecule is needed to lower the barrier of the SO3 hydration reaction, the reaction rate effectively depends on the water dimer concentration. (23,40) Therefore, the low SO3 concentrations during the summer likely result from the large abundance of the water dimer and low SO2 concentration.
Figure 1
Figure 1. (A) Time series of SO3 during the winter (January 20 to March 31, 2019) and summer (June 1 to July 10, 2019), (B) median diurnal patterns of SO3, UVB, and atmospheric water dimer concentrations during the winter and summer, and (C) median normalized intensities of the atmospheric ion SO3·NO3–. Rainy and snowy days were excluded. The shadows show the values from the 25th to 75th percentile. In panel B, the dashed lines show diurnal variations of SO3 during haze and nonhaze days. The water dimer concentration was calculated on the basis of temperature and relative humidity. (26,39) In panel C, the signals of atmospheric ion SO3·NO3– were normalized by the sum of NO3– and HNO3·NO3– that are dominant natural charged ions in urban Beijing (Figure S7).
During the winter and summer, SO3 showed similar diurnal patterns (Figure 1B). During the winter, SO3 levels increased from ∼05:00 and reached their peak at ∼08:30. The abundance of SO3 was higher during the early morning from ∼06:00 to ∼09:00 and night from ∼18:00 to ∼03:00 (the next day) than around noon. Similarly, during the summer, SO3 concentrations increased from ∼4:00 and reached their peak values at ∼07:00. A peak of SO3 in the early morning (∼04:00 to ∼08:00) was also observed. During both the winter and the summer, lower SO3 concentrations were observed around noon when the water dimer concentration reached its minimum level (Figure 1B). Besides water-catalyzed hydration, around noon, a large abundance of other atmospheric components (e.g., H2SO4, HCOOH, HNO3, and oxalic acid) also promoted the conversion of SO3, leading to relatively short lifetimes. In addition, diel patterns of SO3 on nonhaze and haze days in winter are also shown in Figure 1B. The abundance of SO3 exhibited a similar daily pattern during both haze and nonhaze days (Text S8), though the actual values were higher on haze days.
The averaged mass spectra of atmospheric naturally charged ions for a day are shown in Figure S7. The dominant anions in urban Beijing are nitrate ions (NO3– and HNO3·NO3–), similar to the case in Shanghai. (5) Therefore, the normalized intensity of SO3·NO3– by the sum of nitrate ions also can represent the abundance of SO3 in the air. Figure 1C shows the diel variation of the normalized signals of SO3·NO3– in November 2018. The normalized signals also exhibited two peaks, in the early morning (∼6:00 to ∼9:00) and at night (∼17:00 to ∼20:00).
Potential Source Identification for SO3
To investigate the possible sources of SO3 molecules during the early morning and night, we monitored other trace gases (SO2 and NOx), BC, and traffic flow of the main road nearby. (41) During the summer, the average SO3 concentration was 2.9 × 104 molecules cm–3, which is likely close to the detection limit of the instrument. Hence, the possible source identification for SO3 was focused on winter data. During the winter, the median concentrations of SO2, NOx, and BC in PM2.5 exhibited diurnal trends similar to those of SO3 (Figure 2A). On the basis of previous studies of SO2 and together with stable weather conditions (low wind speeds and shallow mixing layer) (Text S11 and Figure S8), the elevated SO2 concentration during the early morning could mainly be attributed to local emissions (e.g., residential and industry emission) and transportation. (42−50) BC concentrations were tightly linked with traffic emission dominated by diesel vehicles (Figure 2A).
Figure 2
Figure 2. (A) Median diurnal variations in the concentrations of SO3, SO2, black carbon (BC), NOx, the approximate abundance term {([BC][SO2])/[(H2O)2]} of SO3, and gasoline and diesel vehicle flow of the “West Third Ring Road”, which was ∼550 m to the west of the sampling station in 2017, (41) and (B) correlation between the SO3 concentration and its approximate abundance term during the night and the early morning (from 18:00 to 08:00 the next day) for the whole field measurement during the winter. In panel A, the units of BC, SO2, and water dimer [(H2O)2] in approximate source terms were micrograms per cubic meter, molecules per cubic meter, and molecules per cubic meter, respectively. In panel B, the SO3 concentrations were divided into logarithmic bins, and the median values in each bin are shown as squares. The orange shadow represents the values from the 25th to 75th percentile.
During the early morning, the UVB intensity was low, which meant that OH radical concentrations from photochemistry were also low, because of the linear correlation between OH concentrations and the ozone photolysis frequency [j(O1D)] in Beijing during daytime. (51) During a summer night in the suburban area of Beijing, OH radical concentrations from ∼0.5 to 3 × 106 cm–3 still can be observed. (52,53) Nevertheless, during the winter in suburban Beijing, the mean observed OH concentrations were <3 × 105 cm–3 at night and <1 × 106 cm–3 in the early morning (06:00–09:00). (54,55) Hence, the oxidation of SO2 by OH radicals was not the main source for SO3 during the early morning and night. In addition, during the early morning, the median ozone concentration was only ∼5 ppb, which was low in comparison to the values during the rest of the day, resulting in a minor contribution to SO3 production from the reaction between sCI and SO2. Although SO3 molecules can also be co-emitted with SO2, (20−22,56,57) transportation is not feasible for SO3 owing to its short lifetime (<1s) in the air. Previous studies based on quantum chemical calculations have suggested that the heterogeneous reaction between SO2 and soot can lead to SO3 formation. (11,12) If this mechanism were to dominate SO3 formation, and further assuming that the SO3 is removed by reaction with the water dimer, the concentration of SO3 would be proportional to ([BC][SO2])/[(H2O)2]. Figure 2A shows that during the early morning (06:00–09:00) and night (from 18:00 to 6:00 the next day), the median diurnal variations of SO3 and ([BC][SO2])/[(H2O)2] were consistent with each other. Also, for the whole measurement period during the winter from 18:00 to 08:00 the next day, the correlation between SO3 and this approximate abundance term was positive [r = 0.7; P < 0.0001 (Figure 2B)]. Furthermore, on nonhaze days, SO3 was tightly linked to particulate sulfate, implying SO3 may originate from heterogeneous reaction (Figure S9). Therefore, our results together suggested the heterogeneous reaction between SO2 and BC could be the possible source of SO3 during the early morning and at night. However, other formation mechanisms (e.g., Criegee intermediate and SO2) may also contribute. (9)
Enhancement of Sulfuric Acid and Sub-2.5 nm Particle Formation
Median diurnal variations of the concentrations or intensities of H2SO4, the sulfuric acid dimer (H2SO4·HSO4–), SO3, sub-2.5 nm particles, CS, SO2, ozone, and UVB during the winter and summer are shown in panels A and B of Figure 3A and B, respectively. During the winter and summer, elevated levels of SO3 and H2SO4 were simultaneously observed in the early morning. During the winter, the median concentrations of H2SO4 during the early morning were comparable with that around noon. In addition, it showed a good correlation (r = 0.7) between atmospheric ions of HSO4– and SO3·NO3– during the early morning (5:00–8:00) and night (from 18:00 to 5:00 the following day) (Figure S10). Thus, the SO3 formed from nonphotochemical processes enhanced H2SO4 formation during the early morning and night. In a recent study in urban Beijing, under clean conditions, oxidation of SO2 by oxidants produced in the ozonolysis of alkenes (i.e., sCI and “dark” OH) was suggested as a source of H2SO4 during the night. (58) This study also pointed out that, under polluted conditions, additional sources of H2SO4 exist. Hence, during the night in urban Beijing, H2SO4 can be enhanced both by SO3 molecules produced by the heterogeneous reaction between BC and SO2 and by the oxidation of SO2 by oxidants from ozonolysis of alkenes.
Figure 3
Figure 3. Median diurnal variations in the concentrations and intensities of SO3, the sulfuric acid (SA) monomer (H2SO4) and dimer, sub-2.5 nm particles, SO2, O3, UVB, and condensation sink (CS) during the (A) winter and (B) summer.
As shown in Figure 3, during the winter or summer, the median concentrations of H2SO4, H2SO4·HSO4–, and sub-2.5 nm particles followed the same diurnal behavior. The concentrations of H2SO4·HSO4– and sub-2.5 nm particles started to increase at ∼5:00. During the early morning during the winter, the median concentrations of H2SO4·HSO4– and sub-2.5 nm particles were comparable with that around noon. On the basis of the studies in urban Shanghai, if atmospheric bases were abundant, the sulfuric acid dimer could be treated as an indicator of nanocluster formation. (5,59) In urban Beijing, the concentrations of atmospheric bases (e.g., amines and ammonia) may also be sufficient for efficient clustering. Thus, the increased level of formation of SO3, possibly produced by the oxidation of SO2 on top of soot particles, can intensify the production of secondary particles and enhance gas to particle conversion during the early morning and night. We note that the contribution to nanoclusters of traffic, or the reaction of SO3 with ammonia/methanol, cannot be wholly excluded. (25,60−62) Our results together point toward the need to control the emission of SO2 and soot to mitigate secondary aerosol formation in urban Beijing.
Supporting Information
Click to copy section linkSection link copied!
The Supporting Information is available free of charge at https://pubs.acs.org/doi/10.1021/acs.estlett.0c00615.
Description of the sampling site (Text S1), the nitrate-CI-APi-LTOF mass spectrometer (Text S2), detection of sulfuric acid with nitrate reagent ions (Text S3), detailed calibration experiment for SO3 (Text S4), quantum chemical calculations (Text S6), computational details (Text S7), PM2.5, black carbon, particulate sulfate, trace gases, meteorological parameters, and UVB measurements (Text S8), sub-3 nm particle measurements (Text S9), calculation of condensation sink (Text S10), source identification of SO2 during the winter (Text S11), high-resolution peak fitting of the 32SO3·NO3– peak and its 34SO3·NO3– main isotope peak (Figure S1), schematic of the calibration experiment setup (Figure S2), time series of normalized signals of H2SO4 and SO3, and [H2O] in the calibration experiment (Figure S3), correlation between normalized SO3 signals measured by the CI-APi-LTOF mass spectrometer and SO3 concentrations formed by photo-oxidation of SO2 by OH radicals (Figure S4), optimized structure of the SO3·(NO3–) cluster (Figure S5), lowest-free energy (at 298 K) structure found for SO3·(NO3–)·H2O (Figure S6), averaged mass spectra of atmospheric naturally charged ions for one whole day (November 10, 2018) (Figure S7), median diurnal variation of the concentrations of SO3 and SO2, the mixing layer heights (MLH), intensities of UVB, and wind speeds during the winter (Figure S8), time profile of the SO3 concentration and mass concentration of sulfate in PM2.5 and median diel variation of SO3 and sulfate for all nonhaze days during the winter measurement period (Figure S9), relationship between the atmospheric ion signals of HSO4– and SO3·NO3– during the night (from 18:00 to 5:00 next day) and early morning (5:00–8:00) from November 9 to 22, 2018 (Figure S10), and comparison of the binding thermodynamics of HNO3·(NO3–) and SO3·(NO3–) ion–molecule clusters (Table S1) (PDF)
Terms & Conditions
Most electronic Supporting Information files are available without a subscription to ACS Web Editions. Such files may be downloaded by article for research use (if there is a public use license linked to the relevant article, that license may permit other uses). Permission may be obtained from ACS for other uses through requests via the RightsLink permission system: http://pubs.acs.org/page/copyright/permissions.html.
Author Information
Click to copy section linkSection link copied!
- Federico Bianchi - Aerosol and Haze Laboratory, Beijing Advanced Innovation Center for Soft Matter Science and Engineering, Beijing University of Chemical Technology, Beijing 100089, China; Institute for Atmospheric and Earth System Research/Physics, Faculty of Science, University of Helsinki, Helsinki 00560, Finland;
http://orcid.org/0000-0003-2996-3604;
- Lei Yao - Aerosol and Haze Laboratory, Beijing Advanced Innovation Center for Soft Matter Science and Engineering, Beijing University of Chemical Technology, Beijing 100089, China; Institute for Atmospheric and Earth System Research/Physics, Faculty of Science, University of Helsinki, Helsinki 00560, Finland;http://orcid.org/0000-0002-2680-1629
- Theo Kurtén - Department of Chemistry, University of Helsinki, Helsinki 00014, Finland;http://orcid.org/0000-0002-6416-4931
- Matti P. Rissanen - Aerosol Physics Laboratory, Physics Unit, Tampere University, Tampere 33100, Finland;http://orcid.org/0000-0003-0463-8098
- Shaojun Zhang - State Key Joint Laboratory of Environment Simulation and Pollution Control, State Environmental Protection Key Laboratory of Sources and Control of Air Pollution Complex, School of Environment, Tsinghua University, Beijing 100084, China;http://orcid.org/0000-0002-2176-6174
- Juha Kangasluoma - Aerosol and Haze Laboratory, Beijing Advanced Innovation Center for Soft Matter Science and Engineering, Beijing University of Chemical Technology, Beijing 100089, China; Institute for Atmospheric and Earth System Research/Physics, Faculty of Science, University of Helsinki, Helsinki 00560, Finland;http://orcid.org/0000-0002-1639-1187
- Lin Wang - Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP3), Department of Environmental Science & Engineering, Fudan University, Shanghai 200438, China;http://orcid.org/0000-0002-4905-3432
- Yongchun Liu - Aerosol and Haze Laboratory, Beijing Advanced Innovation Center for Soft Matter Science and Engineering, Beijing University of Chemical Technology, Beijing 100089, China;http://orcid.org/0000-0002-9055-970X
- Biwu Chu - Institute for Atmospheric and Earth System Research/Physics, Faculty of Science, University of Helsinki, Helsinki 00560, Finland; State Key Joint Laboratory of Environment Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; Center for Excellence in Regional Atmospheric Environment, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China;http://orcid.org/0000-0002-7548-5669
Acknowledgments
Click to copy section linkSection link copied!
The work is supported by Academy of Finland (Center of Excellence in Atmospheric Sciences, project no. 307331, and PROFI3 funding, 311932), the European Research Council via ATM-GTP (742206) and via CHAPAs (850614) and the EMME-CARE project which has received funding from the European Union’s Horizon 2020 Research and Innovation Programme, under Grant Agreement No. 856612.
References
Click to copy section linkSection link copied!
This article references 62 other publications.
- 1Larssen, T.; Lydersen, E.; Tang, D. G.; He, Y.; Gao, J. X.; Liu, H. Y.; Duan, L.; Seip, H. M.; Vogt, R. D.; Mulder, J.; Shao, M.; Wang, Y. H.; Shang, H.; Zhang, X. S.; Solberg, S.; Aas, W.; Okland, T.; Eilertsen, O.; Angell, V.; Li, Q. R.; Zhao, D. W.; Xiang, R. J.; Xiao, J. S.; Luo, J. H. Acid rain in China. Environ. Sci. Technol. 2006, 40 (2), 418– 425, DOI: 10.1021/es0626133Google Scholar1https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD28XmsVSltA%253D%253D&md5=7fb8980553c6c7c404a7e13d24f6e819Acid rain in ChinaLarssen, Thorjorn; Lydersen, Espen; Tang, Dagang; He, Yi; Gao, Jixi; Liu, Haiying; Duan, Lei; Seip, Hans M.; Vogt, Rolf D.; Mulder, Jan; Shao, Min; Wang, Yanhui; Shang, He; Zhang, Xiaoshan; Solberg, Svein; Aas, Wenche; Okland, Tonje; Eilertsen, Odd; Angell, Valter; Liu, Quanru; Zhao, Dawei; Xiang, Renjun; Xiao, Jinshong; Luo, JiahaiEnvironmental Science and Technology (2006), 40 (2), 418-425CODEN: ESTHAG; ISSN:0013-936X. (American Chemical Society)There is no expanded citation for this reference.
- 2Sipilä, M.; Berndt, T.; Petäjä, T.; Brus, D.; Vanhanen, J.; Stratmann, F.; Patokoski, J.; Mauldin, R. L.; Hyvarinen, A. P.; Lihavainen, H.; Kulmala, M. The Role of Sulfuric Acid in Atmospheric Nucleation. Science 2010, 327 (5970), 1243– 1246, DOI: 10.1126/science.1180315Google Scholar2https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A280%3ADC%252BC3c7lvFWiug%253D%253D&md5=e091ca63c1c073ce1f5c63fc0db03d53The role of sulfuric acid in atmospheric nucleationSipila Mikko; Berndt Torsten; Petaja Tuukka; Brus David; Vanhanen Joonas; Stratmann Frank; Patokoski Johanna; Mauldin Roy L 3rd; Hyvarinen Antti-Pekka; Lihavainen Heikki; Kulmala MarkkuScience (New York, N.Y.) (2010), 327 (5970), 1243-6 ISSN:.Nucleation is a fundamental step in atmospheric new-particle formation. However, laboratory experiments on nucleation have systematically failed to demonstrate sulfuric acid particle formation rates as high as those necessary to account for ambient atmospheric concentrations, and the role of sulfuric acid in atmospheric nucleation has remained a mystery. Here, we report measurements of new particles (with diameters of approximately 1.5 nanometers) observed immediately after their formation at atmospherically relevant sulfuric acid concentrations. Furthermore, we show that correlations between measured nucleation rates and sulfuric acid concentrations suggest that freshly formed particles contain one to two sulfuric acid molecules, a number consistent with assumptions that are based on atmospheric observations. Incorporation of these findings into global models should improve the understanding of the impact of secondary particle formation on climate.
- 3Kulmala, M.; Kontkanen, J.; Junninen, H.; Lehtipalo, K.; Manninen, H. E.; Nieminen, T.; Petäjä, T.; Sipilä, M.; Schobesberger, S.; Rantala, P.; Franchin, A.; Jokinen, T.; Jarvinen, E.; Aijala, M.; Kangasluoma, J.; Hakala, J.; Aalto, P. P.; Paasonen, P.; Mikkila, J.; Vanhanen, J.; Aalto, J.; Hakola, H.; Makkonen, U.; Ruuskanen, T.; Mauldin, R. L.; Duplissy, J.; Vehkamaki, H.; Back, J.; Kortelainen, A.; Riipinen, I.; Kurtén, T.; Johnston, M. V.; Smith, J. N.; Ehn, M.; Mentel, T. F.; Lehtinen, K. E.; Laaksonen, A.; Kerminen, V. M.; Worsnop, D. R. Direct observations of atmospheric aerosol nucleation. Science 2013, 339 (6122), 943– 6, DOI: 10.1126/science.1227385Google Scholar3https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXis1Oisb4%253D&md5=1d1f6dd3764359aeb7515f9c57bcf270Direct Observations of Atmospheric Aerosol NucleationKulmala, Markku; Kontkanen, Jenni; Junninen, Heikki; Lehtipalo, Katrianne; Manninen, Hanna E.; Nieminen, Tuomo; Petaejae, Tuukka; Sipilae, Mikko; Schobesberger, Siegfried; Rantala, Pekka; Franchin, Alessandro; Jokinen, Tuija; Jaervinen, Emma; Aeijaelae, Mikko; Kangasluoma, Juha; Hakala, Jani; Aalto, Pasi P.; Paasonen, Pauli; Mikkilae, Jyri; Vanhanen, Joonas; Aalto, Juho; Hakola, Hannele; Makkonen, Ulla; Ruuskanen, Taina; Mauldin, Roy L., III; Duplissy, Jonathan; Vehkamaeki, Hanna; Baeck, Jaana; Kortelainen, Aki; Riipinen, Ilona; Kurten, Theo; Johnston, Murray V.; Smith, James N.; Ehn, Mikael; Mentel, Thomas F.; Lehtinen, Kari E. J.; Laaksonen, Ari; Kerminen, Veli-Matti; Worsnop, Douglas R.Science (Washington, DC, United States) (2013), 339 (6122), 943-946CODEN: SCIEAS; ISSN:0036-8075. (American Association for the Advancement of Science)Atm. nucleation is the dominant source of aerosol particles in the global atm. and an important player in aerosol climate effects. Key steps of this process occur in the sub-2-nm (nm) size range, in which direct size-segregated observations have not been possible until very recently. This work presents detailed observations of atm. nanoparticles and clusters down to 1-nm mobility diam. It identified 3 sep. size regimes <2-nm diam. which build up a phys., chem., and dynamically consistent framework on atm. nucleation; more specifically, aerosol formation via neutral pathways. Results emphasize the important role of org. compds. in atm. aerosol formation, subsequent aerosol growth, radiative forcing, and assocd. feedbacks among biogenic emissions, clouds, and climate.
- 4Bianchi, F.; Tröstl, J.; Junninen, H.; Frege, C.; Henne, S.; Hoyle, C. R.; Molteni, U.; Herrmann, E.; Adamov, A.; Bukowiecki, N.; Chen, X.; Duplissy, J.; Gysel, M.; Hutterli, M.; Kangasluoma, J.; Kontkanen, J.; Kurten, A.; Manninen, H. E.; Munch, S.; Perakyla, O.; Petäjä, T.; Rondo, L.; Williamson, C.; Weingartner, E.; Curtius, J.; Worsnop, D. R.; Kulmala, M.; Dommen, J.; Baltensperger, U. New particle formation in the free troposphere: A question of chemistry and timing. Science 2016, 352 (6289), 1109– 1112, DOI: 10.1126/science.aad5456Google Scholar4https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC28XosValsL4%253D&md5=c8c6c51f81628a151c131d83c3baa086New particle formation in the free troposphere: A question of chemistry and timingBianchi, F.; Troestl, J.; Junninen, H.; Frege, C.; Henne, S.; Hoyle, C. R.; Molteni, U.; Herrmann, E.; Adamov, A.; Bukowiecki, N.; Chen, X.; Duplissy, J.; Gysel, M.; Hutterli, M.; Kangasluoma, J.; Kontkanen, J.; Kuerten, A.; Manninen, H. E.; Muench, S.; Peraekylae, O.; Petaejae, T.; Rondo, L.; Williamson, C.; Weingartner, E.; Curtius, J.; Worsnop, D. R.; Kulmala, M.; Dommen, J.; Baltensperger, U.Science (Washington, DC, United States) (2016), 352 (6289), 1109-1112CODEN: SCIEAS; ISSN:0036-8075. (American Association for the Advancement of Science)New particle formation (NPF) is the source of over half of the atm.'s cloud condensation nuclei, thus influencing cloud properties and Earth's energy balance. Unlike in the planetary boundary layer, few observations of NPF in the free troposphere exist. The authors provided observational evidence that at high altitudes, NPF occurs mainly through condensation of highly oxygenated mols. (HOMs), in addn. to taking place through sulfuric acid-ammonia nucleation. Neutral nucleation is more than 10 times faster than ion-induced nucleation, and growth rates are size-dependent. NPF is restricted to a time window of 1 to 2 days after contact of the air masses with the planetary boundary layer; this is related to the time needed for oxidn. of org. compds. to form HOMs. These findings require improved NPF parameterization in atm. models.
- 5Yao, L.; Garmash, O.; Bianchi, F.; Zheng, J.; Yan, C.; Kontkanen, J.; Junninen, H.; Mazon, S. B.; Ehn, M.; Paasonen, P.; Sipilä, M.; Wang, M.; Wang, X.; Xiao, S.; Chen, H.; Lu, Y.; Zhang, B.; Wang, D.; Fu, Q.; Geng, F.; Li, L.; Wang, H.; Qiao, L.; Yang, X.; Chen, J.; Kerminen, V. M.; Petäjä, T.; Worsnop, D. R.; Kulmala, M.; Wang, L. Atmospheric new particle formation from sulfuric acid and amines in a Chinese megacity. Science 2018, 361 (6399), 278– 281, DOI: 10.1126/science.aao4839Google Scholar5https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC1cXhtlantbvK&md5=1416423dc9523bfe945710d98ffc9b13Atmospheric new particle formation from sulfuric acid and amines in a Chinese megacityYao, Lei; Garmash, Olga; Bianchi, Federico; Zheng, Jun; Yan, Chao; Kontkanen, Jenni; Junninen, Heikki; Mazon, Stephany Buenrostro; Ehn, Mikael; Paasonen, Pauli; Sipilae, Mikko; Wang, Mingyi; Wang, Xinke; Xiao, Shan; Chen, Hangfei; Lu, Yiqun; Zhang, Bowen; Wang, Dongfang; Fu, Qingyan; Geng, Fuhai; Li, Li; Wang, Hongli; Qiao, Liping; Yang, Xin; Chen, Jianmin; Kerminen, Veli-Matti; Petaejae, Tuukka; Worsnop, Douglas R.; Kulmala, Markku; Wang, LinScience (Washington, DC, United States) (2018), 361 (6399), 278-281CODEN: SCIEAS; ISSN:0036-8075. (American Association for the Advancement of Science)Atm. new particle formation (NPF) is an important global phenomenon that is nevertheless sensitive to ambient conditions. According to both observation and theor. arguments, NPF usually requires a relatively high sulfuric acid (H2SO4) concn. to promote the formation of new particles and a low preexisting aerosol loading to minimize the sink of new particles. We investigated NPF in Shanghai and were able to observe both precursor vapors (H2SO4) and initial clusters at a mol. level in a megacity. High NPF rates were obsd. to coincide with several familiar markers suggestive of H2SO4-dimethylamine (DMA)-water (H2O) nucleation, including sulfuric acid dimers and H2SO4-DMA clusters. In a cluster kinetics simulation, the obsd. concn. of sulfuric acid was high enough to explain the particle growth to ∼3 nm under the very high condensation sink, whereas the subsequent higher growth rate beyond this size is believed to result from the added contribution of condensing org. species. These findings will help in understanding urban NPF and its air quality and climate effects, as well as in formulating policies to mitigate secondary particle formation in China.
- 6Chu, B. W.; Kerminen, V. M.; Bianchi, F.; Yan, C.; Petäjä, T.; Kulmala, M. Atmospheric new particle formation in China. Atmos. Chem. Phys. 2019, 19 (1), 115– 138, DOI: 10.5194/acp-19-115-2019Google Scholar6https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC1MXitFyjs7w%253D&md5=ca998646467f1b14af5f8fba2823e6c1Atmospheric new particle formation in ChinaChu, Biwu; Kerminen, Veli-Matti; Bianchi, Federico; Yan, Chao; Petaja, Tuukka; Kulmala, MarkkuAtmospheric Chemistry and Physics (2019), 19 (1), 115-138CODEN: ACPTCE; ISSN:1680-7324. (Copernicus Publications)New particle formation (NPF) studies in China were summarized comprehensively in this paper. NPF frequency, formation rate, and particle growth rate were closely compared among the observations carried out at different types of sites in different regions of China in different seasons, with the aim of exploring the nucleation and particle growth mechanisms. The interactions between air pollution and NPF are discussed, emphasizing the properties of NPF under heavy pollution conditions. The current understanding of NPF cannot fully explain the frequent occurrence of NPF at high aerosol loadings in China, and possible reasons for this phenomenon are proposed. The effects of NPF and some aspects of NPF research requiring further investigation are also summarized in this paper.
- 7Chen, H.; Wang, M.; Yao, L.; Chen, J.; Wang, L. Uptake of Gaseous Alkylamides by Suspended Sulfuric Acid Particles: Formation of Ammonium/Aminium Salts. Environ. Sci. Technol. 2017, 51 (20), 11710– 11717, DOI: 10.1021/acs.est.7b03175Google Scholar7https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2sXhsV2rsrfM&md5=05572bbf5fb96cec3a8cf7b8b3ad0b69Uptake of Gaseous Alkylamides by Suspended Sulfuric Acid Particles: Formation of Ammonium/Aminium SaltsChen, Hangfei; Wang, Mingyi; Yao, Lei; Chen, Jianmin; Wang, LinEnvironmental Science & Technology (2017), 51 (20), 11710-11717CODEN: ESTHAG; ISSN:0013-936X. (American Chemical Society)Amides represent an important class of N-contg. compds. in the atm. that can in theory interact with atm. acidic particles and contribute to secondary aerosol formation. Here, uptake coeffs. (γ) of 6 alkylamides (C1-C3) by suspended sulfuric acid particles were measured using an aerosol flow tube coupled to a high resoln. time-of-flight chem. ionization mass spectrometer (HRToF-CIMS). At 293 K and <3% relative humidity (RH), the measured uptake coeffs. for 6 alkylamides were (4.8-23) × 10-2. A neg. dependence upon RH was obsd. for both N-methylformamide and N,N-dimethylformamide, likely due to decreased mass accommodation coeffs. (α) at lower acidities. A neg. temp. dependence was obsd. for N,N-dimethylformamide under <3% RH, also consistent with the mass accommodation-controlled uptake processes. Chem. anal. of reacted sulfuric acid particles indicates that alkylamides hydrolyzed in the presence of water mols. to form ammonium or aminium. Our results suggest that multiphase uptake of amides will contribute to growth of atm. acidic particles and alter their chem. compn.
- 8Kerminen, V. M.; Chen, X. M.; Vakkari, V.; Petäjä, T.; Kulmala, M.; Bianchi, F. Atmospheric new particle formation and growth: review of field observations. Environ. Res. Lett. 2018, 13 (10), 103003, DOI: 10.1088/1748-9326/aadf3cGoogle Scholar8https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC1MXmt1Witrk%253D&md5=da269476bbf9282c0f21419fd5e01b29Atmospheric new particle formation and growth: review of field observationsKerminen, Veli-Matti; Chen, Xuemeng; Vakkari, Ville; Petaja, Tuukka; Kulmala, Markku; Bianchi, FedericoEnvironmental Research Letters (2018), 13 (10), 103003/1-103003/38CODEN: ERLNAL; ISSN:1748-9326. (IOP Publishing Ltd.)A review. This review focuses on the obsd. characteristics of atm. new particle formation (NPF) in different environments of the global troposphere. After a short introduction, we will present a theor. background that discusses the methods used to analyze measurement data on atm. NPF and the assocd. terminol. We will update on our current understanding of regional NPF, i.e. NPF taking simultaneously place over large spatial scales, and complement that with a full review on reported NPF and growth rates during regional NPF events. We will shortly review atm. NPF taking place at sub-regional scales. Since the growth of newly-formed particles into larger sizes is of great current interest, we will briefly discuss our observation-based understanding on which gaseous compds. contribute to the growth of newly-formed particles, and what implications this will have on atm. cloud condensation nuclei formation. We will finish the review with a summary of our main findings and future outlook that outlines the remaining research questions and needs for addnl. measurements.
- 9Mauldin, R. L.; Berndt, T.; Sipilä, M.; Paasonen, P.; Petäjä, T.; Kim, S.; Kurtén, T.; Stratmann, F.; Kerminen, V. M.; Kulmala, M. A new atmospherically relevant oxidant of sulphur dioxide. Nature 2012, 488 (7410), 193– 196, DOI: 10.1038/nature11278Google Scholar9https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC38XhtFKiurjO&md5=f135832d658d216a9741a5da2be64b25A new atmospherically relevant oxidant of sulphur dioxideMauldin, R. L., III; Berndt, T.; Sipilae, M.; Paasonen, P.; Petaejae, T.; Kim, S.; Kurten, T.; Stratmann, F.; Kerminen, V.-M.; Kulmala, M.Nature (London, United Kingdom) (2012), 488 (7410), 193-196CODEN: NATUAS; ISSN:0028-0836. (Nature Publishing Group)Atm. oxidn. is a key phenomenon which connects atm. chem. with globally challenging environmental issues, e.g., climate change, stratospheric O2 loss, soil and water acidification, and air quality health effects. O3 and OH- and NO3- radicals are generally considered the dominant oxidants which initiate trace gas removal, including pollutants, from the atm. Atm. observations from a boreal forest region in Finland, supported by lab. expts. and theor. considerations, which allowed the authors to identify another compd., probably a stabilized Criegee intermediate (carbonyl oxide with 2 free radical sites) or its deriv., which has a significant capacity to oxidize SO2 and potentially other trace gases, are discussed. This compd. probably enhances atm. reactivity, particularly with regard to H2SO4 prodn., and consequently, atm. aerosol formation. Results suggested this new atmospherically relevant oxidn. route is important relative to OH- oxidn., at least at moderate radical concns. Also, the oxidn. chem. of this compd. seemed tightly linked to the presence of biogenic alkenes.
- 10Welz, O.; Savee, J. D.; Osborn, D. L.; Vasu, S. S.; Percival, C. J.; Shallcross, D. E.; Taatjes, C. A. Direct Kinetic Measurements of Criegee Intermediate (CH2OO) Formed by Reaction of CH2I with O2. Science 2012, 335 (6065), 204– 207, DOI: 10.1126/science.1213229Google Scholar10https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC38XksVShug%253D%253D&md5=33d2432f3b200b4253cc96afa0595422Direct Kinetic Measurements of Criegee Intermediate (CH2OO) Formed by Reaction of CH2I with O2Welz, Oliver; Savee, John D.; Osborn, David L.; Vasu, Subith S.; Percival, Carl J.; Shallcross, Dudley E.; Taatjes, Craig A.Science (Washington, DC, United States) (2012), 335 (6065), 204-207CODEN: SCIEAS; ISSN:0036-8075. (American Association for the Advancement of Science)Ozonolysis is a major tropospheric removal mechanism for unsatd. hydrocarbons which proceeds via Criegee intermediates (carbonyl oxides) which play a key role in tropospheric oxidn. models. Until recently, no gas-phase Criegee intermediate had been obsd., and indirect detns. of their reaction kinetics gave derived rate coeffs. spanning orders of magnitude. This paper reports the direct photoionization mass spectrometric detection of formaldehyde oxide (CH2OO), a product of the reaction of CH2I with O2. This reaction enabled direct lab. detns. of CH2OO kinetics. Upper limits were extd. for reaction rate coeffs. with NO and water. CH2OO reactions with SO2 and NO2 were unexpectedly rapid and implied a substantially greater role of carbonyl oxides in tropospheric SO42- and NO3- chem. models than previously assumed.
- 11He, G. Z.; He, H. DFT studies on the heterogeneous oxidation of SO2 by oxygen functional groups on graphene. Phys. Chem. Chem. Phys. 2016, 18 (46), 31691– 31697, DOI: 10.1039/C6CP06665HGoogle Scholar11https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC28XhslGgtbjO&md5=5f5c6a52cbb3abe1d771e0e956ffbd9cDFT studies on the heterogeneous oxidation of SO2 by oxygen functional groups on grapheneHe, Guangzhi; He, HongPhysical Chemistry Chemical Physics (2016), 18 (46), 31691-31697CODEN: PPCPFQ; ISSN:1463-9076. (Royal Society of Chemistry)The heterogeneous oxidn. of SO2 has been the subject of intense scrutiny in atm. chem. because of the adverse effects of sulfate particles. Although it has been found that the soot particles with a graphene-like structure play an important role in the oxidn. of SO2, little is known about the at.-level mechanism involved. Here, we studied the oxidn. of SO2 on oxygen-functionalized graphene using d. functional theory (DFT) calcn. The results showed that SO2 is oxidized by the epoxide group via a two-step mechanism, where the C-O bond away from the SO2 is broken first, followed by the breaking of the other C-O bond and the synchronous formation of a new S-O bond. The energy barriers are significantly decreased when solvation free energies are involved, suggesting that humidity is favorable for promoting the oxidn. by reducing the reaction barrier. The energy barriers for H2SO3 oxidn. are much higher than that for SO2 oxidn., indicating that the direct conversion of SO2 to SO3 is the main pathway for the oxidn. of SO2 by oxygen-functionalized graphene sheets in both the gas phase and soln. The reduced d. gradient (RDG) anal. showed that the hydrogen bond formed between H2SO3 and epoxide groups enhances the stability of the reaction complex, and is responsible for the high energy barrier that has to be overcome for the reaction to proceed. These atomistic studies proposed a two-step mechanism for the oxidn. of SO2 on the oxygen-functionalized graphene-like carbonaceous surfaces under ambient conditions.
- 12He, G. Z.; Ma, J. Z.; He, H. Role of Carbonaceous Aerosols in Catalyzing Sulfate Formation. ACS Catal. 2018, 8 (5), 3825– 3832, DOI: 10.1021/acscatal.7b04195Google Scholar12https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC1cXmtVWrtLc%253D&md5=459a3df2c042cb38c4b4ba5dbdc54e2dRole of Carbonaceous Aerosols in Catalyzing Sulfate FormationHe, Guangzhi; Ma, Jinzhu; He, HongACS Catalysis (2018), 8 (5), 3825-3832CODEN: ACCACS; ISSN:2155-5435. (American Chemical Society)The persistent and fast formation of sulfate is a primary factor driving the explosive growth of fine particles and exacerbating China's severe haze development. However, the underlying mechanism for the persistent prodn. of sulfate remains highly uncertain. Here, we demonstrate that soot is not only a major component of the particulate matter but also a natural carbocatalyst to activate mol. O2 and catalyze the oxidn. of SO2 to sulfate under ambient conditions. Moreover, high relative humidity, typically occurring in severe haze events, can greatly accelerate the catalytic cycle by reducing the reaction barriers, leading to faster sulfate prodn. The formation pathway of sulfate catalyzed by carbonaceous soot aerosols uses the ubiquitous O2 as the ultimate oxidant and can proceed at night when photochem. is reduced. The high relative humidity during haze episodes can further promote the soot-catalyzed sulfate-producing process. Therefore, this study reveals a missing and widespread source for the persistent sulfate haze formation in the open atm., particularly under highly polluted conditions characterized by high concns. of both SO2 and particulate carbon, and is helpful to the development of more efficient policies to mitigate and control haze pollution.
- 13Lizzio, A. A.; DeBarr, J. A. Mechanism of SO2 removal by carbon. Energy Fuels 1997, 11 (2), 284– 291, DOI: 10.1021/ef960197+Google Scholar13https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADyaK2sXit1ersbY%253D&md5=d66565b7c7e2ad7c54204e3817fb0086Mechanism of SO2 Removal by CarbonLizzio, Anthony A.; DeBarr, Joseph A.Energy & Fuels (1997), 11 (2), 284-291CODEN: ENFUEM; ISSN:0887-0624. (American Chemical Society)The reaction of SO2 with carbon in the presence of O2 and H2O involves a series of reactions that leads to the formation of sulfuric acid as the final product. The rate-detg. step in the overall process is the oxidn. of SO2 to SO3. Three SO2 oxidn. reactions are possible. Adsorbed SO2 (C-SO2) can react either with gas-phase O2 or with adsorbed oxygen (C-O complex) to form sulfur trioxide (SO3), or gas phase SO2 can react directly with the C-O complex. In optimizing the SO2 removal capabilities of carbon, most studies only assume a given mechanism for SO2 adsorption and conversion to H2SO4 to be operable. The appropriate SO2 oxidn. step and role of the C-O complex in this mechanism remain to be detd. The ultimate goal of this study was to prep. activated char from Illinois coal with optimal properties for low-temp. (80-150°) removal of sulfur dioxide from coal combustion flue gas. The SO2 adsorption capacity of activated char was found to be inversely proportional to the amt. of oxygen adsorbed on its surface. A temp.-programmed desorption technique was developed to titrate those sites responsible for adsorption of SO2 and conversion to H2SO4. On the basis of these results, a mechanism for SO2 removal by carbon was proposed. The derived rate expression showed SO2 adsorption to be dependent only on the fundamental rate const. and concn. of carbon atoms designated as free sites. Recent studies indicate a similar relationship exists between the rate of carbon gasification (in CO2 or H2O) and the no. of reactive sites as detd. by transient kinetics expts. Utilizing the concept of active or free sites, it was possible to produce a char from Illinois coal having an SO2 adsorption capacity surpassing that of the best available com. activated carbon.
- 14Han, C.; Liu, Y. C.; Ma, J. Z.; He, H. Key role of organic carbon in the sunlight-enhanced atmospheric aging of soot by O2. Proc. Natl. Acad. Sci. U. S. A. 2012, 109 (52), 21250– 21255, DOI: 10.1073/pnas.1212690110Google Scholar14https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXoslShsQ%253D%253D&md5=9391213fb02bfb393b48c2c7708b9e41Key role of organic carbon in the sunlight-enhanced atmospheric aging of soot by O2Han, Chong; Liu, Yongchun; Ma, Jinzhu; He, HongProceedings of the National Academy of Sciences of the United States of America (2012), 109 (52), 21250-21255, S21250/1-S21250/6CODEN: PNASA6; ISSN:0027-8424. (National Academy of Sciences)Soot particles are ubiquitous in the atm. and have important climatic and health effects. The aging processes of soot during long-range transport result in variability in its morphol., microstructure, and hygroscopic and optical properties, subsequently leading to the modification of soot's climatic and health effects. In the present study the aging process of soot by mol. O2 under simulated sunlight irradn. is investigated. Org. carbon components on the surface of soot are found to play a key role in soot aging and are transformed into oxygen-contg. org. species including quinones, ketones, aldehydes, lactones, and anhydrides. These oxygen-contg. species may become adsorption centers of water and thus enhance the cloud condensation nuclei and ice nuclei activities of soot. Under irradn. of 25 mW·cm-2, the apparent rate consts. (k1,obs) for loss or formation of species on soot aged by 20% O2 were larger by factors of 1.5-3.5 than those on soot aged by 100 ppb O3. Considering the abundance of O2 in the troposphere and its higher photoreactivity rate, the photochem. oxidn. by O2 under sunlight irradn. should be a very important aging process for soot.
- 15He, G.; He, H. Water Promotes the Oxidation of SO2 by O2 over Carbonaceous Aerosols. Environ. Sci. Technol. 2020, 54 (12), 7070– 7077, DOI: 10.1021/acs.est.0c00021Google Scholar15https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB3cXotVehtLw%253D&md5=297fa7f3d5416f09f8bd1f5dbb54e01cWater Promotes the Oxidation of SO2 by O2 over Carbonaceous AerosolsHe, Guangzhi; He, HongEnvironmental Science & Technology (2020), 54 (12), 7070-7077CODEN: ESTHAG; ISSN:0013-936X. (American Chemical Society)Severe haze episodes typically occur with concurrent high relative humidity. The vital role of water in promoting SO2 oxidn. by O2 on carbonaceous soot surfaces was identified at the at. level by first-principles calcns. Water mols. dissoc. into surface hydroxyl groups through a self-catalyzed process at ambient conditions. Surface hydroxyl groups, acting as facilitators, significantly accelerated SO2 conversion to SO3 (particulate SO42- precursor) over soot aerosols by reducing reaction barriers. Specifically, hydroxyl groups activated reactants and stabilized transition states and products via H-bond interactions, making reactions thermodynamically and kinetically more favorable at room temp. Results indicated atm. humidity plays an important role in enhancing atm. oxidn. capacity, thereby exacerbating SO2 oxidn. and severe haze development. Results also unraveled a mechanism of surface hydroxyl-assisted O2 and water dissocn. over metal-free carbo-catalysts at ambient conditions.
- 16Novakov, T.; Chang, S. G.; Harker, A. B. Sulfates as Pollution Particulates - Catalytic Formation on Carbon (soot) Particles. Science 1974, 186 (4160), 259– 261, DOI: 10.1126/science.186.4160.259Google Scholar16https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADyaE2cXlsFyjtbY%253D&md5=5c495f23330508ce6f01f100fbd79949Sulfates as pollution particulates. Catalytic formation on carbon (soot) particlesNovakov, T.; Chang, S. G.; Harker, A. B.Science (Washington, DC, United States) (1974), 186 (4160), 259-61CODEN: SCIEAS; ISSN:0036-8075.Exptl. evidence (obtained by electron spectroscopy for chem. anal.) is presented which shows that finely divided C (soot) particles may play a major role in the catalytic oxidn. of SO2 to sulfate in polluted atms. The results obtained with sulfates produced in the lab. by the oxidn. of SO2 on graphite particles and combustion-produced soot particles are compared with the properties and behavior of ambient sulfates. The proposed SO2 oxidn. mechanism is qual. consistent with field observation.
- 17Zhao, Y.; Liu, Y. C.; Ma, J. Z.; Ma, Q. X.; He, H. Heterogeneous reaction of SO2 with soot: The roles of relative humidity and surface composition of soot in surface sulfate formation. Atmos. Environ. 2017, 152, 465– 476, DOI: 10.1016/j.atmosenv.2017.01.005Google Scholar17https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2sXosVWiuw%253D%253D&md5=d071aeed78f41efd34c590ceaef6cd55Heterogeneous reaction of SO2 with soot: The roles of relative humidity and surface composition of soot in surface sulfate formationZhao, Yan; Liu, Yongchun; Ma, Jinzhu; Ma, Qingxin; He, HongAtmospheric Environment (2017), 152 (), 465-476CODEN: AENVEQ; ISSN:1352-2310. (Elsevier Ltd.)The conversion of SO2 to sulfates on the surface of soot is still poorly understood. Soot samples with different fractions of unsatd. hydrocarbons and oxygen-contg. groups were prepd. by combusting n-hexane under well-controlled conditions. The heterogeneous reaction of SO2 with soot was investigated using in situ attenuated total internal reflection IR (ATR-IR) spectroscopy, ion chromatog. (IC) and a flow tube reactor at the ambient pressure and relative humidity (RH). Water promoted SO2 adsorption and sulfate formation at the RH range from 6% to 70%, while exceeded water condensed on soot was unfavorable for sulfate formation due to inhibition of SO2 adsorption when RH was higher than 80%. The surface compn. of soot, which was governed by combustion conditions, also played an important role in the heterogeneous reaction of SO2 with soot. This effect was found to greatly depend on RH. At low RH of 6%, soot with the highest fuel/oxygen ratio of 0.162 exhibited a max. uptake capacity for SO2 because it contained a large amt. of arom. C-H groups, which acted as active sites for SO2 adsorption. At RH of 54%, soot produced with a fuel/oxygen ratio of 0.134 showed the highest reactivity toward SO2 because it contained appropriate amts. of arom. C-H groups and oxygen-contg. groups, subsequently leading to the optimal surface concns. of both SO2 and water. These results suggest that variation in the surface compn. of soot from different sources and/or resulting from chem. aging in the atm. likely affects the conversion of SO2 to sulfates.
- 18He, X.; Pang, S. F.; Ma, J. B.; Zhang, Y. H. Influence of relative humidity on heterogeneous reactions of O3 and O3/SO2 with soot particles: Potential for environmental and health effects. Atmos. Environ. 2017, 165, 198– 206, DOI: 10.1016/j.atmosenv.2017.06.049Google Scholar18https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2sXhtFamt7vO&md5=97288dbd6b4337acebf019a3134e4e27Influence of relative humidity on heterogeneous reactions of O3 and O3/SO2 with soot particles: Potential for environmental and health effectsHe, Xiang; Pang, Shufeng; Ma, Jiabi; Zhang, YunhongAtmospheric Environment (2017), 165 (), 198-206CODEN: AENVEQ; ISSN:1352-2310. (Elsevier Ltd.)The heterogeneous reactions of soot particles with O3 and the mixt. of O3 and SO2 were studied as a function of relative humidities (RHs). The reactions were followed in real time using microscopic Fourier transform IR (micro-FTIR) spectrometer to obtain kinetic data. The results show that the ketone (C=O) group is the main product of the O3/soot reaction, and the sulfate is identified on the surface of soot particles in the presence of O3/SO2. Both reactions are sensitive to RHs and surrounding water significantly promotes the proceeding of the heterogeneous reactions. For the O3/soot reaction, the pseudo-first-order rate const. increases from 3.2 × 10-4 s-1 to 7.1 × 10-4 s-1 with increasing RH in the range of 1%-82%. When O3 and SO2 exist simultaneously during the reaction, the reaction rate and uptake coeff. are all enhanced by about an order of magnitude as the RH increases from 1% to 83%. The high productions of the ketone and sulfate on soot surface are of highly hydrophilic, which play a key role in environmental effect under humid environment. The possible reaction mechanism speculates that products of arom. carbonyls and dihydrofuran species on soot particles will be more harmful to human health.
- 19Zhang, F.; Wang, Y.; Peng, J.; Chen, L.; Sun, Y.; Duan, L.; Ge, X.; Li, Y.; Zhao, J.; Liu, C.; Zhang, X.; Zhang, G.; Pan, Y.; Wang, Y.; Zhang, A. L.; Ji, Y.; Wang, G.; Hu, M.; Molina, M. J.; Zhang, R. An unexpected catalyst dominates formation and radiative forcing of regional haze. Proc. Natl. Acad. Sci. U. S. A. 2020, 117 (8), 3960– 3966, DOI: 10.1073/pnas.1919343117Google Scholar19https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB3cXjvFGksrc%253D&md5=331fd6695f9b154e575fb2d8b7c0f129An unexpected catalyst dominates formation and radiative forcing of regional hazeZhang, Fang; Wang, Yuan; Peng, Jianfei; Chen, Lu; Sun, Yele; Duan, Lian; Ge, Xinlei; Li, Yixin; Zhao, Jiayun; Liu, Chao; Zhang, Xiaochun; Zhang, Gen; Pan, Yuepeng; Wang, Yuesi; Zhang, Annie L.; Ji, Yuemeng; Wang, Gehui; Hu, Min; Molina, Mario J.; Zhang, RenyiProceedings of the National Academy of Sciences of the United States of America (2020), 117 (8), 3960-3966CODEN: PNASA6; ISSN:0027-8424. (National Academy of Sciences)Although regional haze adversely affects human health and possibly counteracts global warming from increasing levels of greenhouse gases, the formation and radiative forcing of regional haze on climate remain uncertain. By combining field measurements, lab. expts., and model simulations, we show a remarkable role of black carbon (BC) particles in driving the formation and trend of regional haze. Our anal. of long-term measurements in China indicates declined frequency of heavy haze events along with significantly reduced SO2, but negligibly alleviated haze severity. Also, no improving trend exists for moderate haze events. Our complementary lab. expts. demonstrate that SO2 oxidn. is efficiently catalyzed on BC particles in the presence of NO2 and NH3, even at low SO2 and intermediate relative humidity levels. Inclusion of the BC reaction accounts for ∼90-100% and 30-50% of the sulfate prodn. during moderate and heavy haze events, resp. Calcns. using a radiative transfer model and accounting for the sulfate formation on BC yield an invariant radiative forcing of nearly zero W m2 on the top of the atm. throughout haze development, indicating small net climatic cooling/warming but large surface cooling, atm. heating, and air stagnation. This BC catalytic chem. facilitates haze development and explains the obsd. trends of regional haze in China. Our results imply that redn. of SO2 alone is insufficient in mitigating haze occurrence and highlight the necessity of accurate representation of the BC chem. and radiative properties in predicting the formation and assessing the impacts of regional haze.
- 20Shen, J. L.; Zheng, C. H.; Xu, L. J.; Zhang, Y.; Zhang, Y. X.; Liu, S. J.; Gao, X. Atmospheric emission inventory of SO3 from coal-fired power plants in China in the period 2009–2014. Atmos. Environ. 2019, 197, 14– 21, DOI: 10.1016/j.atmosenv.2018.10.008Google Scholar20https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC1cXitVygs7jL&md5=afb682ca28aa880a2201ae72fcd488a8Atmospheric emission inventory of SO3 from coal-fired power plants in China in the period 2009-2014Shen, Jiali; Zheng, Chenghang; Xu, Linjie; Zhang, Yang; Zhang, Yongxin; Liu, Shaojun; Gao, XiangAtmospheric Environment (2019), 197 (), 14-21CODEN: AENVEQ; ISSN:1352-2310. (Elsevier Ltd.)Sulfur trioxide (SO3) pollution is becoming another severe problem in coal-fired power plants after SO2, NOx, and PM, however, the characteristics of SO3 emission in China remains unclear. In this paper, we established a refined activity data, and summarized the removal efficiency of different control technologies according to the literature review and field test results. An emission inventory of SO3 from coal-fired power plants in China between 2009 and 2014 was developed, which indicated the SO3 emission increased from 199.7 kilotons (kt) to 314.6 kt at an av. annual growth rate of 9.7%. The results show that Neimenggu, Sh‾anxi, Jiangsu, Shandong, Guangdong and Guizhou were the largest emitters, accounting for 49.7% of the total SO3 emissions in 2014. We analyzed the historical data with ArcGIS system, which allocates the emission into 36 km × 36 km grid cells. In addn., the result shows the unevenly spatial distribution. Combined with future economic development as well as implementation of policy, three different scenarios were set to project SO3 emission in coal-fired power plants in 2020, which represented the potential of SO3 emission redn. Compared with scenario A, SO3 emission can be reduced to 83.9 kt in scenario B, and in scenarios C, SO3 emission can be reduced to 38.4 kt. Coal-fired power plants should adopt different technol. routes to meet the ultra-low emission requirement and reduce the SO3 emission according to the boiler type, sulfur content, and the emission std.
- 21Yang, Z.; Ji, P.; Li, Q.; Jiang, Y.; Zheng, C.; Wang, Y.; Gao, X.; Lin, R. Comprehensive understanding of SO3 effects on synergies among air pollution control devices in ultra-low emission power plants burning high-sulfur coal. J. Cleaner Prod. 2019, 239, 118096, DOI: 10.1016/j.jclepro.2019.118096Google Scholar21https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC1MXhs1CntbnN&md5=fa4c384c4dff27f71a90c4dba88f87e3Comprehensive understanding of SO3 effects on synergies among air pollution control devices in ultra-low emission power plants burning high-sulfur coalYang, Zhengda; Ji, Peidong; Li, Qingyi; Jiang, Ye; Zheng, Chenghang; Wang, Yi; Gao, Xiang; Lin, RiyiJournal of Cleaner Production (2019), 239 (), 118096CODEN: JCROE8; ISSN:0959-6526. (Elsevier Ltd.)The environmental issue of SO3 pollution caused by coal-fired power plants attracts increasing attention. This work focused on the synergies between air pollution control devices in a 660 MW power plant burning high-sulfur coal. Parameters such as gas temp. and flow rate were varied within wide ranges under actual conditions. Both continuously tested SO3 concn. and online operational data were combined to establish a correlation between device performance and operational parameter. Results indicated that the gas temp. acted as a bridge of synergies between the electrostatic precipitator (ESP) and wet electrostatic precipitator (WESP). The SO3 removal efficiency across the ESP increased from 60.3% to 91.1% with the gas temp. decreasing from 136.7 to 114.8°C, leading to the increase in corona current and the decrease in spark-over frequency of WESP. Moreover, addnl. elec. field stages are also effective to enhance the corona current and reduce spark-over frequency. Furthermore, deviations between the design and operational data within 0-100% loading provided a correction to appropriately choose the gas velocity. With the proposed countermeasures, the SO3 emission can achieve a favorable level less than 5 mg/m3. The research findings provide a valuable tech. pathway to eliminate the SO3 emission from power plants burning high-sulfur coal.
- 22Roy, B.; Chen, L. G.; Bhattacharya, S. Nitrogen Oxides, Sulfur Trioxide, and Mercury Emissions during Oxyfuel Fluidized Bed Combustion of Victorian Brown Coal. Environ. Sci. Technol. 2014, 48 (24), 14844– 14850, DOI: 10.1021/es504667rGoogle Scholar22https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXhvFGktbjE&md5=8a172a28941748f050c794ddd1c017dcNitrogen Oxides, Sulfur Trioxide, and Mercury Emissions during Oxy-fuel Fluidized Bed Combustion of Victorian Brown CoalRoy, Bithi; Chen, Luguang; Bhattacharya, SankarEnvironmental Science & Technology (2014), 48 (24), 14844-14850CODEN: ESTHAG; ISSN:0013-936X. (American Chemical Society)This study investigates, for the first time, the NOx, N2O, SO3, and Hg emissions from combustion of a Victorian brown coal in a 10 kWth fluidized bed unit under oxy-fuel combustion conditions. Compared to air combustion, lower NOx emissions and higher N2O formation were obsd. in the oxy-fuel atm. These NOx redn. and N2O formations were further enhanced with steam in the combustion environment. The NOx concn. level in the flue gas was within the permissible limit in coal-fired power plants in Victoria. Therefore, an addnl. NOx removal system will not be required using this coal. In contrast, both SO3 and gaseous mercury concns. were considerably higher under oxy-fuel combustion compared to that in the air combustion. Around 83% of total gaseous mercury released was Hg0, with the rest emitted as Hg2+. Therefore, to control harmful Hg0, a mercury removal system may need to be considered to avoid corrosion in the boiler and CO2 sepn. units during the oxy-fuel fluidized-bed combustion using this coal.
- 23Morokuma, K.; Muguruma, C. Ab-Initio Molecular-Orbital Study of the Mechanism of the Gas-Phase Reaction SO3+H2O - Importance of the 2nd Water Molecule. J. Am. Chem. Soc. 1994, 116 (22), 10316– 10317, DOI: 10.1021/ja00101a068Google Scholar23https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADyaK2cXms1Ckt7Y%253D&md5=3009e4c4460d0b49f24c631bc34c5294Ab initio Molecular Orbital Study of the Mechanism of the Gas Phase Reaction SO3 + H2O: Importance of the Second Water MoleculeMorokuma, Keiji; Muguruma, ChizuruJournal of the American Chemical Society (1994), 116 (22), 10316-17CODEN: JACSAT; ISSN:0002-7863.An ab initio MO method was used to calc. the structures and energetics of complexes and transition states for the reaction of nH2O + SO3 → (n-1)H2SO4 for n = 0 and 1. While the barrier for the 1:1 reaction is very high, two water mols. can react with SO3 very easily to convert it to sulfuric acid. The transition state for this easy reaction is six-centered, with transfer of two protons taking place simultaneously.
- 24Kolb, C. E.; Jayne, J. T.; Worsnop, D. R.; Molina, M. J.; Meads, R. F.; Viggiano, A. A. Gas-Phase Reaction of Sulfur-Trioxide with Water-Vapor. J. Am. Chem. Soc. 1994, 116 (22), 10314– 10315, DOI: 10.1021/ja00101a067Google Scholar24https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADyaK2cXms1Ckt7c%253D&md5=da41b22cb0e8382cf2356b40268d788aGas Phase Reaction of Sulfur Trioxide with Water VaporKolb, C. E.; Jayne, J. T.; Worsnop, D. R.; Molina, M. J.; Meads, R. F.; Viggiano, A. A.Journal of the American Chemical Society (1994), 116 (22), 10314-15CODEN: JACSAT; ISSN:0002-7863.Castleman and co-workers have interpreted the gas phase SO3/H2O reaction in terms of adduct formation followed by unimol. rearrangement to H2SO4: SO3 + H2O + (M) → SO3·H2O + (M) (1); SO3·H2O → H2SO4 (2). However, recent theor. calcns. by Popov et al., Hoffmann and Schleyer, and Morokuma and Muguruma have cast serious doubt on this interpretation. These studies find that the computed activation barrier for reaction 2 is significantly larger than the calcd. binding energy for the SO3·H2O adduct, indicating that any adduct with sufficient internal energy to rearrange will more likely simply dissoc. back to reactants. Exptl. kinetics results reported here also cast serious doubt on the mechanism represented by reactions 1 and 2. We have investigated the gas phase SO3 + H2O reaction in an atm. pressure turbulent flow reactor designed to minimize the influence of wall reactions. We have also studied the reaction of SO3 and H2O vapor as a function of temp. over the range of -30 to +60°, observing a significant (>10×) increase in reaction rate as the temp. is lowered over this range. This observation, combined with the data shown and the calcns. of Morokuma and Muguruma, leads us to propose that a significant portion of the obsd. SO3 consumption likely involves reaction with the water dimer: SO3 + (H2O)2 → H2SO4 + H2O which Morokuma and Muguruma calc. proceeds through a six center transition state with a very small activation energy. The obsd. neg. temp. dependence is presumably due to the higher abundance of water dimer at lower temps. as well as a more favorable competition between reaction 3 and the alternative path to form an SO3.H2O adduct: SO3 + (H2O)2 → SO3.H2O + H2O (4). Reaction 4 is calcd. to be approx. 3.5 kcal/mol exothermic. It is reasonable to assume that the fraction of reaction between SO3 and (H2O)2 proceeding through the six-center transition state computed for reaction 3 will also increase with decreasing temp. At this time it is unclear whether H2SO4 is also formed directly through the reaction of the SO3.H2O adduct with water vapor: SO3.H2O + H2O → H2SO4 + H2O.
- 25Li, H.; Zhong, J.; Vehkamaki, H.; Kurten, T.; Wang, W. G.; Ge, M. F.; Zhang, S. W.; Li, Z. S.; Zhang, X. H.; Francisco, J. S.; Zeng, X. C. Self-Catalytic Reaction of SO3 and NH3 To Produce Sulfamic Acid and Its Implication to Atmospheric Particle Formation. J. Am. Chem. Soc. 2018, 140 (35), 11020– 11028, DOI: 10.1021/jacs.8b04928Google Scholar25https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC1cXhsVOjsL%252FN&md5=2ce70a20fa5287e046fb317d9b4953e0Self-Catalytic Reaction of SO3 and NH3 To Produce Sulfamic Acid and Its Implication to Atmospheric Particle FormationLi, Hao; Zhong, Jie; Vehkamaki, Hanna; Kurten, Theo; Wang, Weigang; Ge, Maofa; Zhang, Shaowen; Li, Zesheng; Zhang, Xiuhui; Francisco, Joseph S.; Zeng, Xiao ChengJournal of the American Chemical Society (2018), 140 (35), 11020-11028CODEN: JACSAT; ISSN:0002-7863. (American Chemical Society)Sulfur trioxide (SO3) is one of the most active chem. species in the atm., and its atm. fate has profound implications to air quality and human health. The dominant gas-phase loss pathway for SO3 is generally believed to be the reaction with water mols., resulting in sulfuric acid. The latter is viewed as a crit. component in the new particle formation (NPF). Herein, a new and competitive loss pathway for SO3 in the presence of abundant gas-phase ammonia (NH3) species is identified. Specifically, the reaction between SO3 and NH3, which produces sulfamic acid, can be self-catalyzed by the reactant (NH3). In dry and heavily polluted areas with relatively high concns. of NH3, the effective rate const. for the bimol. SO3-NH3 reaction can be sufficiently fast through this new loss pathway for SO3 to become competitive with the conventional loss pathway for SO3 with water. Furthermore, this study shows that the final product of the reaction, namely, sulfamic acid, can enhance the fastest possible rate of NPF from sulfuric acid and dimethylamine (DMA) by about a factor of 2. An alternative source of stabilizer for acid-base clustering in the atm. is suggested, and this new mechanism for NPF has potential to improve atm. modeling in highly polluted regions.
- 26Sarkar, S.; Oram, B. K.; Bandyopadhyay, B. Influence of Ammonia and Water on the Fate of Sulfur Trioxide in the Troposphere: Theoretical Investigation of Sulfamic Acid and Sulfuric Acid Formation Pathways. J. Phys. Chem. A 2019, 123 (14), 3131– 3141, DOI: 10.1021/acs.jpca.8b09306Google Scholar26https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC1MXlvVSlur4%253D&md5=1e408f19798d1330180a0acd1d4a6fb4Influence of Ammonia and Water on the Fate of Sulfur Trioxide in the Troposphere: Theoretical Investigation of Sulfamic Acid and Sulfuric Acid Formation PathwaysSarkar, Saptarshi; Oram, Binod Kumar; Bandyopadhyay, BimanJournal of Physical Chemistry A (2019), 123 (14), 3131-3141CODEN: JPCAFH; ISSN:1089-5639. (American Chemical Society)The reaction of NH3 with SO3 as a potential sulfamic acid source in the troposphere was examd. by electronic structure and chem. kinetic calcns. The hydrolysis reaction, a known major atm. SO3 decay channel, was also assessed. The catalytic effect of NH3 and water on both the reactions was studied. Rate coeffs. for all studied reaction mechanisms were calcd. using transition state theory with pre-equil. approxn. Calcd. rate coeffs. for several catalyzed hydrolysis and ammonolysis processes were much higher (∼105 to ∼109 times) than the gas kinetic limit at ambient temp. With a temp. decrease due to neg. temp. dependence of rate coeffs., that difference became even larger (up to ∼1016 times). Hence, to remove discrepancies, rate coeffs. for all studied reaction mechanisms were calcd. using master chem. equations. Results showed marked improvements; only one mechanism exhibited a slightly higher rate coeff. above the gas kinetic limit. Rate coeffs. for catalyzed reaction mechanisms obtained from the master equation also showed neg. temp. dependence, albeit to a much smaller extent. The uncatalyzed ammonolysis reaction, similar to the corresponding hydrolysis, was too slow to have any practical atm. implications. For both reactions, NH3-catalyzed mechanisms had higher rate coeffs. than water-catalyzed mechanisms. Between hydrolysis and ammonolysis, the latter showed a higher rate coeff. Despite that, ammonolysis is expected to have negligible contribution for tropospheric SO3 loss due to the large difference in concns. between water and NH3 in the troposphere.
- 27Lv, G. C.; Sun, X. M.; Zhang, C. X.; Li, M. Understanding the catalytic role of oxalic acid in SO3 hydration to form H2SO4 in the atmosphere. Atmos. Chem. Phys. 2019, 19 (5), 2833– 2844, DOI: 10.5194/acp-19-2833-2019Google Scholar27https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC1MXosVahur4%253D&md5=44add63e2ab82d65cb6d2837a2b3d449Understanding the catalytic role of oxalic acid in SO3 hydration to form H2SO4 in the atmosphereLv, Guochun; Sun, Xiaomin; Zhang, Chenxi; Li, MeiAtmospheric Chemistry and Physics (2019), 19 (5), 2833-2844CODEN: ACPTCE; ISSN:1680-7324. (Copernicus Publications)The hydration of SO3 plays an important role in atm. sulfuric acid formation. Some atm. species can be involved in and facilitate the reaction. In this work, using quantum chem. calcns., we show that oxalic acid, the most common dicarboxylic acid in the atm., can effectively catalyze the hydration of SO3. The energy barrier of the SO3 hydration reaction catalyzed by oxalic acid (cTt, tTt, tCt and cCt conformers) is a little higher or less than 1 kcal mol-1, which is lower than the energy barrier of 5.17 kcal mol-1 for water-catalyzed SO3 hydration. Compared with the rates of the SO3 hydration reaction catalyzed by oxalic acid and water, it can be found that in the upper troposphere the OA-catalyzed SO3 hydration can play an important role in promoting SO3 hydration. It leads us to conclude that the involvement of oxalic acid in SO3 hydration to form H2SO4 is significant in the atm.
- 28Bandyopadhyay, B.; Kumar, P.; Biswas, P. Ammonia Catalyzed Formation of Sulfuric Acid in Troposphere: The Curious Case of a Base Promoting Acid Rain. J. Phys. Chem. A 2017, 121 (16), 3101– 3108, DOI: 10.1021/acs.jpca.7b01172Google Scholar28https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2sXlsVemsrk%253D&md5=3327e885e2a231e07cc7536ea86308d3Ammonia Catalyzed Formation of Sulfuric Acid in Troposphere: The Curious Case of a Base Promoting Acid RainBandyopadhyay, Biman; Kumar, Pradeep; Biswas, ParthaJournal of Physical Chemistry A (2017), 121 (16), 3101-3108CODEN: JPCAFH; ISSN:1089-5639. (American Chemical Society)Electronic structure calcns. were performed to assess the role of NH3 in catalyzing H2SO4 formation through SO3 hydrolysis in Earth atm. The uncatalyzed process involves a high activation barrier and, until now, is mainly known to occur in Earth atm. only when catalyzed by water and acids. This work showed that SO3 hydrolysis can be very efficiently catalyzed by NH3, the most abundant basic component in Earth atm. Based on the magnitude of relative potential energies and rate coeffs., NH3 was detd. best among all studied catalysts until now (water and acids) and could be a considerable factor for tropospheric H2SO4 formation. The calcd. rate coeff. (at 298° K) of the NH3-catalyzed reaction was ∼105-107 times greater than that for water catalyzed reaction. Based on relative rates of NH3 and water catalyzed processes, tropospheric NH3, in conjunction with water, could be the key factor detg. the H2SO4 formation rate. NH3 could surpass water in catalyzing H2SO4 formation via SO3 hydrolysis at various tropospheric altitudes depending on relative concns.
- 29Long, B.; Chang, C. R.; Long, Z. W.; Wang, Y. B.; Tan, X. F.; Zhang, W. J. Nitric acid catalyzed hydrolysis of SO3 in the formation of sulfuric acid: A theoretical study. Chem. Phys. Lett. 2013, 581, 26– 29, DOI: 10.1016/j.cplett.2013.07.012Google Scholar29https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXhtFynt7jN&md5=80ed449b68b064f74ffe8d948122356aNitric acid catalyzed hydrolysis of SO3 in the formation of sulfuric acid: A theoretical studyLong, Bo; Chang, Chun-Ran; Long, Zheng-Wen; Wang, Yi-Bo; Tan, Xing-Feng; Zhang, Wei-JunChemical Physics Letters (2013), 581 (), 26-29CODEN: CHPLBC; ISSN:0009-2614. (Elsevier B.V.)The gas-phase hydrolysis of SO3 in the presence of one water mol., two water mols., and nitric acid is studied using high level quantum chem. methods and transition state theory. The calcd. results demonstrate that nitric acid exerts a strong catalytic role in the hydrolysis of SO3 because the activated barrier of hydrolysis of SO3 with the assistance of nitric acid is reduced to ∼3.7 kcal/mol, which is ∼20 kcal/mol lower than that of the SO3 reaction with water relative to the resp. pre-reactive complex.
- 30Fleig, D.; Vainio, E.; Andersson, K.; Brink, A.; Johnsson, F.; Hupa, M. Evaluation of SO3Measurement Techniques in Air and Oxy-Fuel Combustion. Energy Fuels 2012, 26 (9), 5537– 5549, DOI: 10.1021/ef301127xGoogle Scholar30https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC38Xht1KjsrjM&md5=5554922b0714c5545df97860a0fddc8bEvaluation of SO3 Measurement Techniques in Air and Oxy-Fuel CombustionFleig, Daniel; Vainio, Emil; Andersson, Klas; Brink, Anders; Johnsson, Filip; Hupa, MikkoEnergy & Fuels (2012), 26 (9), 5537-5549CODEN: ENFUEM; ISSN:0887-0624. (American Chemical Society)SO2 is enriched in oxy-fuel combustion due to flue-gas recycle, and a significant higher SO3 concn. can be expected compared to air-firing. Since SO3 can cause high and low temp. corrosion, it is important to measure the SO3 concn. under oxy-fuel fired conditions. However, measurement of SO3 is not straightforward, since SO3 is a highly reactive gas. This paper presents an exptl. study in the Chalmers oxy-fuel test unit, comparing different SO3 measurement techniques applied during oxy-fuel and air combustion. Propane (60 kWth) was used as fuel and SO2 was injected in the oxidizer to generate a controllable amt. of SO3. The SO3 concn. was measured with four techniques: the controlled condensation method, the salt method, the isopropanol absorption bottle method, and with the Pentol SO3 monitor (previously: Severn Science analyzer). The controlled condensation method was used as the std. for comparison. Addnl., the acid dew-point temp. was measured with a dew-point meter. The controlled condensation and the salt method gave comparable results, and the repeatability with these methods was good. The SO3 concns. measured with the Pentol SO3 monitor differed in av. less than 20% from the SO3 concns. obtained with the controlled condensation method. With the isopropanol absorption bottle method, a large amt. of the SO2 was absorbed in the isopropanol soln., which gives a pos. bias if the SO2 is oxidized to sulfate in the isopropanol soln. This was minimized by reducing the measurement time, bubbling argon through the absorption bottles after the measurement to force the SO2 out, and analyzing the soln. immediately after the measurement. No principal differences between measuring the SO3 concn. during oxy-fuel combustion and air-firing were obtained. However, a correction factor for the mass flow meter of the Pentol SO3 monitor has to be used because of the high CO2 concn. during oxy-fuel operation.
- 31Lovejoy, E. R.; Hanson, D. R.; Huey, L. G. Kinetics and products of the gas-phase reaction of SO3 with water. J. Phys. Chem. 1996, 100 (51), 19911– 19916, DOI: 10.1021/jp962414dGoogle Scholar31https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADyaK28XntFSgt7w%253D&md5=97e38a420104d879949e9d20edfd087eKinetics and products of the gas-phase reaction of SO3 with waterLovejoy, E. R.; Hanson, D. R.; Huey, L. G.Journal of Physical Chemistry (1996), 100 (51), 19911-19916CODEN: JPCHAX; ISSN:0022-3654. (American Chemical Society)The kinetics of the gas-phase reactions of SO3 with H2O and D2O were studied over the temp. range 250-360 K in N2 with a laminar flow reactor coupled to a chem. ionization mass spectrometer. The SO3 loss is second order in the water concn., is independent of pressure (20-80 Torr N2, 300 K), and has a strong neg. temp. dependence and a significant H/D isotope effect (kH2O ≈ 2kD2O). The yield of sulfuric acid is 1.0 ± 0.5 per SO3 consumed. These observations are consistent with the rapid assocn. of SO3 and H2O to form the adduct H2OSO3 which reacts with water to produce sulfuric acid. The first-order rate coeffs. for loss of SO3 by reaction with H2O and D2O are given by kI(s-1) = (2.26 ± 0.85) × 10-43T exp((6544 ± 106)/T)[H2O]2 and (9.45 ± 2.68) × 10-44T exp((6573 ± 82)/T)[D2O]2, where T ≡ K and [H2O, D2O] ≡ mol. cm-3. The errors are the uncertainty at the 95% confidence level for precision only. Anal. of the temp. dependence of the SO3 loss yields an upper limit for the H2O-SO3 bond enthalpy of 13 kcal mol-1.
- 32Arnold, S. T.; Morris, R. A.; Viggiano, A. A.; Jayne, J. T. Ion Chemistry Relevant for Chemical-Ionization Detection of SO3. J. Geophys. Res. 1995, 100 (D7), 14141– 14146, DOI: 10.1029/95JD01004Google ScholarThere is no corresponding record for this reference.
- 33Jayne, J. T.; Poschl, U.; Chen, Y. M.; Dai, D.; Molina, L. T.; Worsnop, D. R.; Kolb, C. E.; Molina, M. J. Pressure and temperature dependence of the gas-phase reaction of SO3 with H2O and the heterogeneous reaction of SO3 with H2O/H2SO4 surfaces. J. Phys. Chem. A 1997, 101 (51), 10000– 10011, DOI: 10.1021/jp972549zGoogle Scholar33https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADyaK2sXnvVCntrc%253D&md5=2e4f06ccb347cfff4e4d162b8405d473Pressure and temperature dependence of the gas-phase reaction of SO3 with H2O and the heterogeneous reaction of SO3 with H2O/H2SO4 surfacesJayne, John T.; Poeschl, Ulrich; Chen, Yu-min; Dai, David; Molina, Luisa T.; Worsnop, Douglas R.; Kolb, Charles E.; Molina, Mario J.Journal of Physical Chemistry A (1997), 101 (51), 10000-10011CODEN: JPCAFH; ISSN:1089-5639. (American Chemical Society)The gas-phase reaction of SO3 with H2O and the heterogeneous reaction of SO3 with H2O-H2SO4 surfaces have been studied in a fast flow reactor coupled to a chem. ionization mass spectrometer (CIMS) for species detection. The gas-phase reaction was studied under turbulent flow conditions over the pressure range from 100 to 760 Torr N2 and the temp. range from 283 to 370 K. The loss rate of SO3 was measured under pseudo-first-order conditions; it exhibits a second-order dependence on water vapor concn. and has a strong neg. temp. dependence. The first-order rate coeff. for the SO3 loss by gas-phase reaction shows no significant pressure dependence and can be expressed as kI(s-1) = 3.90 × 10-41 exp(6830.6/T)[H2O]2 where [H2O] is in units of mol. cm-3 and T is in Kelvin. The overall uncertainty of our exptl. detd. rate coeffs. is estd. to be ±20%. At sufficiently low SO3 concns. (<1012 mol. cm-3) the rate coeff. is independent of the initial SO3 level, as expected for a gas-phase reaction mechanism involving one SO3 and two H2O mols. However, at higher concns. and lower temps., increased rate coeffs. were obsd., indicating a fast heterogeneous reaction after the onset of binary homogeneous nucleation of acid hydrate clusters leading to particle formation, which was verified by light-scattering expts. The heterogeneous loss of SO3 to the reactor walls has also been investigated under low pressure (1.1-12.5 Torr) laminar flow conditions. The loss rate is highly dependent on the humidity of the surface. In the presence of excess water the reactive sticking coeff. approaches unity and the wall loss rate is gas diffusion limited; under dry conditions it approaches zero, as expected. The atm. implications of the homogeneous and heterogeneous SO3-water reaction are discussed.
- 34Sorokin, A.; Katragkou, E.; Arnold, F.; Busen, R.; Schumann, U. Gaseous SO3 and H2SO4 in the exhaust of an aircraft gas turbine engine: measurements by CIMS and implications for fuel sulfur conversion to sulfur (VI) and conversion of SO3 to H2SO4. Atmos. Environ. 2004, 38 (3), 449– 456, DOI: 10.1016/j.atmosenv.2003.09.069Google Scholar34https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD3sXptlChsLY%253D&md5=44c27e80a2f1377f489239e91f7a3427Gaseous SO3 and H2SO4 in the exhaust of an aircraft gas turbine engine: measurements by CIMS and implications for fuel sulfur conversion to sulfur (VI) and conversion of SO3 to H2SO4Sorokin, A.; Katragkou, E.; Arnold, F.; Busen, R.; Schumann, U.Atmospheric Environment (2004), 38 (3), 449-456CODEN: AENVEQ; ISSN:1352-2310. (Elsevier Science B.V.)An estn. of the conversion efficiency (.vepsiln.) of fuel sulfur to SO3 and H2SO4, where .vepsiln.=([SO3]+[H2SO4])/[ST] and [ST] is the total sulfur atom concn. in the exhaust at the exit of an aircraft gas-turbine combustor, was derived from measurements by comparison with model results. The major results of the presented CIMS expts. and their interpretation with a model simulation are: (i) The efficiency is .vepsiln.=2.3±1% at an exhaust age of about 5 ms from the combustor exit; (ii) The SO3 mols. represent a major fraction of sulfur (VI) gases .vepsiln.A<50% and an essential SO3-conversion to H2SO4 takes place in the sampling line where the exhaust gases spend a sufficiently long time and where the temp. is lower than in the hot exhaust. The coincidence of .vepsiln. from our work (measurements with the sampling point in the exhaust just behind the combustor exit) and .vepsiln. the measurements in an exhaust at a plume age of about 1 s suggests that the sulfur (VI) formation is inefficient in the post-combustor flow inside the aircraft engine.
- 35Berndt, T.; Scholz, W.; Mentler, B.; Fischer, L.; Hoffmann, E. H.; Tilgner, A.; Hyttinen, N.; Prisle, N. L.; Hansel, A.; Herrmann, H. Fast Peroxy Radical Isomerization and OH Recycling in the Reaction of OH Radicals with Dimethyl Sulfide. J. Phys. Chem. Lett. 2019, 10 (21), 6478– 6483, DOI: 10.1021/acs.jpclett.9b02567Google Scholar35https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC1MXhvFWltrjP&md5=0d91ffa9cadc1365ffbfb0a48fe0373bFast Peroxy Radical Isomerization and OH Recycling in the Reaction of OH Radicals with Dimethyl SulfideBerndt, T.; Scholz, W.; Mentler, B.; Fischer, L.; Hoffmann, E. H.; Tilgner, A.; Hyttinen, N.; Prisle, N. L.; Hansel, A.; Herrmann, H.Journal of Physical Chemistry Letters (2019), 10 (21), 6478-6483CODEN: JPCLCD; ISSN:1948-7185. (American Chemical Society)Di-Me sulfide (DMS), produced by marine organisms, represents the most abundant, biogenic sulfur emission into the Earth's atm. The gas-phase degrdn. of DMS is mainly initiated by the reaction with the OH radical forming first CH3SCH2O2 radicals from the dominant H-abstraction channel. It is exptl. shown that these peroxy radicals undergo a two-step isomerization process finally forming a product consistent with the formula HOOCH2SCHO. The isomerization process is accompanied by OH recycling. The rate-limiting first isomerization step, CH3SCH2O2 → CH2SCH2OOH, followed by O2 addn., proceeds with k = (0.23 ± 0.12) s-1 at 295 ± 2 K. Competing bimol. CH3SCH2O2 reactions with NO, HO2, or RO2 radicals are less important for trace-gas conditions over the oceans. Results of atm. chem. simulations demonstrate the predominance (≥95%) of CH3SCH2O2 isomerization. The rapid peroxy radical isomerization, not yet considered in models, substantially changes the understanding of DMS's degrdn. processes in the atm.
- 36Jokinen, T.; Sipilä, M.; Junninen, H.; Ehn, M.; Lönn, G.; Hakala, J.; Petäjä, T.; Mauldin, R. L.; Kulmala, M.; Worsnop, D. R. Atmospheric sulphuric acid and neutral cluster measurements using CI-APi-TOF. Atmos. Chem. Phys. 2012, 12 (9), 4117– 4125, DOI: 10.5194/acp-12-4117-2012Google Scholar36https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC38XhtFOns7vM&md5=33186776d4f9cc0c19aa9298e0874ed0Atmospheric sulphuric acid and neutral cluster measurements using CI-APi-TOFJokinen, T.; Sipila, M.; Junninen, H.; Ehn, M.; Lonn, G.; Hakala, J.; Petaja, T.; Mauldin, R. L., III; Kulmala, M.; Worsnop, D. R.Atmospheric Chemistry and Physics (2012), 12 (9), 4117-4125CODEN: ACPTCE; ISSN:1680-7316. (Copernicus Publications)The first ambient measurements using nitrate ion based Chem. Ionization with the Atm. Pressure interface Time-Of-Flight mass spectrometer (CI-APi-TOF) for sulfuric acid and neutral cluster detection are presented. We have found CI-APi-TOF a highly stable and sensitive tool for mol. sulfuric acid detection. The lowest limit of detection for sulfuric acid was detd. to be 3.6 × 104 mols. cm-3 for 15 min averaging. Signals from sulfuric acid clusters up to tetramer contg. ammonia were also obtained but these were found to result from naturally charged clusters formed by ion induced clustering in the atm. during nucleation. Opposite to earlier studies with cluster mass spectrometers, we had no indication of neutral clusters. The reason is either less efficient charging of clusters in comparison to mol. sulfuric acid, or the low concn. of neutral clusters at our measurement site during these particular nucleation events. We show that utilizing high resoln. mass spectrometry is crucial in sepg. the weak sulfuric acid cluster signal from other compds.
- 37Kürten, A.; Rondo, L.; Ehrhart, S.; Curtius, J. Calibration of a chemical ionization mass spectrometer for the measurement of gaseous sulfuric acid. J. Phys. Chem. A 2012, 116 (24), 6375– 86, DOI: 10.1021/jp212123nGoogle Scholar37https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC38XivVOhsLc%253D&md5=983dc0a569a9a926132b2e25e7aeeab1Calibration of a Chemical Ionization Mass Spectrometer for the Measurement of Gaseous Sulfuric AcidKuerten, Andreas; Rondo, Linda; Ehrhart, Sebastian; Curtius, JoachimJournal of Physical Chemistry A (2012), 116 (24), 6375-6386CODEN: JPCAFH; ISSN:1089-5639. (American Chemical Society)Accurate measurement of gaseous H2SO4 concn. is crucial within many fields of atm. science. Instruments using chem. ionization mass spectrometry (CIMS) to measure H2SO4 require careful calibration. This work established a calibration source to provide stable, adjustable H2SO4 concns. This calibration system initiates H2SO4 prodn. by oxidizing SO2 by OH-. OH- is produced by UV photolysis of water vapor. A numerical model calcs. the H2SO4 concn. at the calibration source outlet. From comparison of this concn. and CIMS-measured signals, a calibration factor is derived. This factor was evaluated to be 1.1 × 1010/cm3, in good agreement with literature values for other H2SO4-measuring CIMS instruments. The described calibration system and results are discussed. Since the set-up is external to the CIMS instrument, it offers the possibility for future CIMS inter-comparison measurements by providing defined, stable H2SO4 concns.
- 38Mohler, O.; Reiner, T.; Arnold, F. The Formation of SO5– by Gas-Phase Ion–Molecule Reactions. J. Chem. Phys. 1992, 97 (11), 8233– 8239, DOI: 10.1063/1.463394Google ScholarThere is no corresponding record for this reference.
- 39Anglada, J. M.; Hoffman, G. J.; Slipchenko, L. V.; Costa, M. M.; Ruiz-Lopez, M. F.; Francisco, J. S. Atmospheric Significance of Water Clusters and Ozone-Water Complexes. J. Phys. Chem. A 2013, 117 (40), 10381– 10396, DOI: 10.1021/jp407282cGoogle Scholar39https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXhsVehs7bK&md5=ee23b2ef1fea6c22aed226dc11742083Atmospheric Significance of Water Clusters and Ozone-Water ComplexesAnglada, Josep M.; Hoffman, Gerald J.; Slipchenko, Lyudmila V.; M. Costa, Marilia; Ruiz-Lopez, Manuel F.; Francisco, Joseph S.Journal of Physical Chemistry A (2013), 117 (40), 10381-10396CODEN: JPCAFH; ISSN:1089-5639. (American Chemical Society)Ozone-water complexes O3···(H2O)n (n = 1-4) have been theor. investigated using QCISD and CCSD-(T) methods along with the 6-311G-(2df,2p), 6-311+G-(2df,2p), aug-cc-pVDZ, aug-cc-pVTZ, and aug-cc-pVQZ basis sets and extrapolation to CBS limit. For comparison, water clusters (H2O)n (n = 1-4) have also been studied at the same level of theory. The ozone-water complexes are held together by a combination of weak specific hydrogen-bonding and van der Waals interactions. Surprisingly, the hydrogen-bonded complexes are not necessarily the most stable ones. In particular, in the most stable 1:1 complex structure the main stabilizing factors come from van der Waals interactions. The high accuracy of the calcd. binding energies provides a reliable basis to discuss the abundance of these clusters in the atm. We predict concns. up to 9.24 × 1015, 3.91 × 1014, and 2.02 × 1914 mols.·cm-3 for water dimer, trimer, and tetramer in very hot and humid conditions and that the concns. of these clusters would remain significant up to 10 km of altitude in the Earth's atm. The concn. of O3···H2O is predicted to be between 1 and 2 orders of magnitude higher than previous estn. from the literature: up to 5.74 × 108 mols.·cm-3 in very hot and humid conditions at ground level and up to 1.56 × 107 mols.·cm-3 at 10 km of altitude of the Earth's atm. The concns. of the other ozone-water clusters, O3··(H2O)2, O3···(H2O)3, and O3···(H2O)4, are predicted to be very small or even negligible in the atm.
- 40Larson, L. J.; Kuno, M.; Tao, F. M. Hydrolysis of sulfur trioxide to form sulfuric acid in small water clusters. J. Chem. Phys. 2000, 112 (20), 8830– 8838, DOI: 10.1063/1.481532Google Scholar40https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD3cXivFClsbo%253D&md5=4478be77743b6fb67dce7726c000be41Hydrolysis of sulfur trioxide to form sulfuric acid in small water clustersLarson, Laura J.; Kuno, Mayuso; Tao, Fu-MingJournal of Chemical Physics (2000), 112 (20), 8830-8838CODEN: JCPSA6; ISSN:0021-9606. (American Institute of Physics)The hydrolysis reaction of sulfur trioxide to form sulfuric acid in small water clusters is investigated using d. function theory and ab initio methods. The equil. geometries for the reactant clusters that contain SO3 and one to four water mols., SO3·(H2O)n, n=1-4, as well as the corresponding transition state and product clusters, are calcd. at the levels of B3LYP/6-31+G*, B3LYP/6-311++G**, and MP2/6-311++G**. The relative energies of the reactant, transition state, and product are detd. for each of the four clusters. The energy barrier required to form H2SO4 from the reactant cluster is found to decrease sharply with the no. of water mols. in the cluster. Most significantly, the SO3·(H2O)4 cluster is found to be unstable and to form the ion pair HSO4- and H3O+ with little or no energy barrier. This work reveals the possibility of more pathways for the formation of sulfuric acid than have been previously considered.
- 41Yang, D. Y.; Zhang, S. J.; Niu, T. L.; Wang, Y. J.; Xu, H. L.; Zhang, K. M.; Wu, Y. High-resolution mapping of vehicle emissions of atmospheric pollutants based on large-scale, real-world traffic datasets. Atmos. Chem. Phys. 2019, 19 (13), 8831– 8843, DOI: 10.5194/acp-19-8831-2019Google Scholar41https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC1MXhsFClsbbL&md5=4ec8d149d11b50863671ca500f5c72f5High-resolution mapping of vehicle emissions of atmospheric pollutants based on large-scale, real-world traffic datasetsYang, Daoyuan; Zhang, Shaojun; Niu, Tianlin; Wang, Yunjie; Xu, Honglei; Zhang, K. Max; Wu, YeAtmospheric Chemistry and Physics (2019), 19 (13), 8831-8843CODEN: ACPTCE; ISSN:1680-7324. (Copernicus Publications)On-road vehicle emissions are a major contributor to elevated air pollution levels in populous metropolitan areas. We developed a link-level emissions inventory of vehicular pollutants, called EMBEV-Link (Link-level Emission factor Model for the BEijing Vehicle fleet), based on multiple datasets extd. from the extensive road traffic monitoring network that covers the entire municipality of Beijing, China (16 400 km2). We employed the EMBEV-Link model under various traffic scenarios to capture the significant variability in vehicle emissions, temporally and spatially, due to the real-world traffic dynamics and the traffic restrictions implemented by the local government. The results revealed high carbon moNOx ide (CO) and total hydrocarbon (THC) emissions in the urban area (i.e., within the Fifth Ring Road) and during rush hours, both assocd. with the passenger vehicle traffic. By contrast, considerable fractions of nitrogen oxides (NOx), fine particulate matter (PM2.5) and black carbon (BC) emissions were present beyond the urban area, as heavy-duty trucks (HDTs) were not allowed to drive through the urban area during daytime. The EMBEV-Link model indicates that nonlocal HDTs could account for 29% and 38% of estd. total on-road emissions of NOx and PM2.5, which were ignored in previous conventional emission inventories. We further combined the EMBEV-Link emission inventory and a computationally efficient dispersion model, RapidAir, to simulate vehicular NOx concns. at fine resolns. (10 m × 10 m in the entire municipality and 1 m × 1 m in the hotspots). The simulated results indicated a close agreement with ground observations and captured sharp concn. gradients from line sources to ambient areas. During the nighttime when the HDT traffic restrictions are lifted, HDTs could be responsible for approx. 10 μg m-3 of NOx in the urban area. The uncertainties of conventional top-down allocation methods, which were widely used to enhance the spatial resoln. of vehicle emissions, are also discussed by comparison with the EMBEV-Link emission inventory.
- 42Xu, W. Y.; Zhao, C. S.; Ran, L.; Lin, W. L.; Yan, P.; Xu, X. B. SO2 noontime-peak phenomenon in the North China Plain. Atmos. Chem. Phys. 2014, 14 (15), 7757– 7768, DOI: 10.5194/acp-14-7757-2014Google Scholar42https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXhs1amu7rN&md5=58dfe1e208074e1caf0a1c9cbd46cf2dSO2 noontime-peak phenomenon in the North China PlainXu, W. Y.; Zhao, C. S.; Ran, L.; Lin, W. L.; Yan, P.; Xu, X. B.Atmospheric Chemistry and Physics (2014), 14 (15), 7757-7768, 12 pp.CODEN: ACPTCE; ISSN:1680-7324. (Copernicus Publications)A phenomenon of frequent noontime SO2 concn. peaks was discovered in a detailed anal. of the SO2 concns. in the North China Plain (NCP). The possible causes and their contributions are analyzed. The impacts of such a phenomenon on the sulfur cycle were studied and the implications of the phenomenon for atm. chem., cloud physics, and climate were discussed. Different from the more common SO2 diurnal patterns with high nighttime concns., NCP witnessed high frequencies of noontime SO2 peaks, with an occurrence frequency of 50 to 72% at four stations. Down mixing of elevated pollution layers, plume transport processes, mountain-valley winds, and fog/high RH haze events were the possible causes. The contribution of each process varies from day to day and from station to station, however, none of those four processes can be neglected. SO2 peaks occurring during noontime instead of nighttime will lead to a 13 to 35% increase in sulfur dry deposition, a 9 to 23% increase in gas phase oxidn., and an 8 to 33% increase in aq. phase conversions, which will increase the hygroscopicity and the light scattering of aerosols, thus having important impacts on atm. chem., cloud physics, and climate.
- 43Liu, J.; Mauzerall, D. L.; Chen, Q.; Zhang, Q.; Song, Y.; Peng, W.; Klimont, Z.; Qiu, X. H.; Zhang, S. Q.; Hu, M.; Lin, W. L.; Smith, K. R.; Zhu, T. Air pollutant emissions from Chinese households: A major and underappreciated ambient pollution source. Proc. Natl. Acad. Sci. U. S. A. 2016, 113 (28), 7756– 7761, DOI: 10.1073/pnas.1604537113Google Scholar43https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC28XhtFentrvE&md5=a900007ac72f2fd7a7492ba12f868e63Air pollutant emissions from Chinese households: A major and underappreciated ambient pollution sourceLiu, Jun; Mauzerall, Denise L.; Chen, Qi; Zhang, Qiang; Song, Yu; Peng, Wei; Klimont, Zbigniew; Qiu, Xinghua; Zhang, Shiqiu; Hu, Min; Lin, Weili; Smith, Kirk R.; Zhu, TongProceedings of the National Academy of Sciences of the United States of America (2016), 113 (28), 7756-7761CODEN: PNASA6; ISSN:0027-8424. (National Academy of Sciences)As part of the 12th Five-Year Plan, the Chinese government has developed air pollution prevention and control plans for key regions with a focus on the power, transport, and industrial sectors. Here, we investigate the contribution of residential emissions to regional air pollution in highly polluted eastern China during the heating season, and find that dramatic improvements in air quality would also result from redn. in residential emissions. We use the Weather Research and Forecasting model coupled with Chem. to evaluate potential residential emission controls in Beijing and in the Beijing, Tianjin, and Hebei (BTH) region. In Jan. and Feb. 2010, relative to the base case, eliminating residential emissions in Beijing reduced daily av. surface PM2.5 (particulate mater with aerodynamic diam. equal or smaller than 2.5 μm) concns. by 14 ± 7 μg·m-3 (22 ± 6% of a baseline concn. of 67 ± 41 μg·m-3; mean ± SD). Eliminating residential emissions in the BTH region reduced concns. by 28 ± 19 μg·m-3 (40 ± 9% of 67 ± 41 μg·m-3), 44 ± 27 μg·m-3 (43 ± 10% of 99 ± 54 μg·m-3), and 25 ± 14 μg·m-3 (35 ± 8% of 70 ± 35 μg·m-3) in Beijing, Tianjin, and Hebei provinces, resp. Annually, elimination of residential sources in the BTH region reduced emissions of primary PM2.5 by 32%, compared with 5%, 6%, and 58% achieved by eliminating emissions from the transportation, power, and industry sectors, resp. We also find air quality in Beijing would benefit substantially from redns. in residential emissions from regional controls in Tianjin and Hebei, indicating the value of policies at the regional level.
- 44Li, R.; Fu, H. B.; Cui, L. L.; Li, J. L.; Wu, Y.; Meng, Y.; Wang, Y. T.; Chen, J. M. The spatiotemporal variation and key factors of SO2 in 336 cities across China. J. Cleaner Prod. 2019, 210, 602– 611, DOI: 10.1016/j.jclepro.2018.11.062Google Scholar44https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC1cXit1eit7rF&md5=ea12483750c7677120be7b3ff532137eThe spatiotemporal variation and key factors of SO2 in 336 cities across ChinaLi, Rui; Fu, Hongbo; Cui, Lulu; Li, Junlin; Wu, Yu; Meng, Ya; Wang, Yutao; Chen, JianminJournal of Cleaner Production (2019), 210 (), 602-611CODEN: JCROE8; ISSN:0959-6526. (Elsevier Ltd.)Sulfur dioxide (SO2) pollution has become a severe concern in China, which is closely linked to human health. Here, the officially released data of SO2 in the 336 prefecture-level cities in 2015 across the whole China were firstly collected to understand the spatiotemporal variation of the SO2 concn. At a national scale, the SO2 concn. was highest in winter, followed by one in spring and autumn, and the lowest one in summer. The spatial econometric models, the geog. wt. regression (GWR) model, and the generalized additive model (GAM) were then applied to examine the interaction of socioeconomic factors (e.g., gross domestic prodn. (GDP)) and the meteorol. indicators (e.g., pptn.) on the SO2 level in the 336 cities over China. The results suggested that the SO2 concn. was neg. assocd. with GDP, pptn., wind speed (WS), and relative humidity (RH), while it showed the pos. relationship with gross industrial prodn. (GIP), population, and temp. GDP in the Jiangsu and Zhejiang provinces presented the neg. correlations with the SO2 concn., suggesting the adaptation of industrial structure has occurred in the developed region. The pos. effect of GIP on the SO2 concn. increased from West China to North China because many energy-intensive industries were concd. on North China. The GAM anal. suggested that the combined effects of the adverse meteorol. condition (e.g., RH = 50-60%) and the higher GIP contributed to severe SO2 pollution. Therefore, the SO2 emission from the heavy industries esp. in NCP should be reduced and many energy-intensive plants in the region should be moved to some cities with favorable diffusion condition.
- 45Huang, Q.; Cheng, S. Y.; Perozzi, R. E.; Perozzi, E. F. Use of a MM5-CAMx-PSAT Modeling System to Study SO2 Source Apportionment in the Beijing Metropolitan Region. Environ. Model. Assess. 2012, 17 (5), 527– 538, DOI: 10.1007/s10666-012-9312-8Google ScholarThere is no corresponding record for this reference.
- 46Kampa, M.; Castanas, E. Human health effects of air pollution. Environ. Pollut. 2008, 151 (2), 362– 367, DOI: 10.1016/j.envpol.2007.06.012Google Scholar46https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD1cXhsVGqsbg%253D&md5=6ca25818591d347f98c3f3bc0bcfbd36Human health effects of air pollutionKampa, Marilena; Castanas, EliasEnvironmental Pollution (Amsterdam, Netherlands) (2008), 151 (2), 362-367CODEN: ENPOEK; ISSN:0269-7491. (Elsevier B.V.)A review. Hazardous chems. escape to the environment by a no. of natural and/or anthropogenic activities and may cause adverse effects on human health and the environment. Increased combustion of fossil fuels in the last century is responsible for the progressive change in the atm. compn. Air pollutants, such as carbon monoxide (CO), sulfur dioxide (SO2), nitrogen oxides (NOx), volatile org. compds. (VOCs), ozone (O3), heavy metals, and respirable particulate matter (PM2.5 and PM10), differ in their chem. compn., reaction properties, emission, time of disintegration and ability to diffuse in long or short distances. Air pollution has both acute and chronic effects on human health, affecting a no. of different systems and organs. It ranges from minor upper respiratory irritation to chronic respiratory and heart disease, lung cancer, acute respiratory infections in children and chronic bronchitis in adults, aggravating pre-existing heart and lung disease, or asthmatic attacks. In addn., short- and long-term exposures have also been linked with premature mortality and reduced life expectancy. These effects of air pollutants on human health and their mechanism of action are briefly discussed. The effect of air pollutants on human health and underlying mechanisms of cellular action are discussed.
- 47Zhong, Q. R.; Shen, H. Z.; Yun, X.; Chen, Y. L.; Ren, Y. A.; Xu, H. R.; Shen, G. F.; Ma, J. M.; Tao, S. Effects of International Fuel Trade on Global Sulfur Dioxide Emissions. Environ. Sci. Technol. Lett. 2019, 6 (12), 727– 731, DOI: 10.1021/acs.estlett.9b00617Google Scholar47https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC1MXitFCns7nM&md5=3495e2a64b0aeb64a3213e8fc7e52e4bEffects of International Fuel Trade on Global Sulfur Dioxide EmissionsZhong, Qirui; Shen, Huizhong; Yun, Xiao; Chen, Yilin; Ren, Yu'ang; Xu, Haoran; Shen, Guofeng; Ma, Jianmin; Tao, ShuEnvironmental Science & Technology Letters (2019), 6 (12), 727-731CODEN: ESTLCU; ISSN:2328-8930. (American Chemical Society)Fossil fuel combustion is the dominant source of global sulfur dioxide (SO2) emissions. With rapid globalization, the expansion of international fuel trade may have profound impacts on SO2 emissions due to the mixing and the spatial reallocation of fuels with varied quality (e.g., sulfur contents), which has not been clearly addressed. Here, by introducing international fuel trade and three addnl. counterfactual scenarios, we first assessed the impacts of fuel trade on global SO2 emissions for the period 1980-2030. In 2014 international fuel trade caused an increase in global SO2 emissions from hard coal and oil consumption by 4% and 71%, resp., with stronger influences found for individual countries. By changing the fuel trade choice, global SO2 emissions attributable to fuel trade would be reduced by 78%. We also showed that such effects of fuel trade on SO2 emissions continuously increased from 1980 to 2014 and will keep increasing in the foreseeable future due to more frequent fuel trading under globalization.
- 48Klimont, Z.; Smith, S. J.; Cofala, J. The last decade of global anthropogenic sulfur dioxide: 2000–2011 emissions. Environ. Res. Lett. 2013, 8 (1), 014003, DOI: 10.1088/1748-9326/8/1/014003Google Scholar48https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXhsFeisb3F&md5=0baecab9161b1fbb9a2695fc697675c6The last decade of global anthropogenic sulfur dioxide: 2000-2011 emissionsKlimont, Z.; Smith, S. J.; Cofala, J.Environmental Research Letters (2013), 8 (1), 014003CODEN: ERLNAL; ISSN:1748-9326. (IOP Publishing Ltd.)The evolution of global and regional anthropogenic SO2 emissions in the last decade has been estd. through a bottom-up calcn. After increasing until about 2006, we est. a declining trend continuing until 2011. However, there is strong spatial variability, with North America and Europe continuing to reduce emissions, with an increasing role of Asia and international shipping. China remains a key contributor, but the introduction of stricter emission limits followed by an ambitious program of installing flue gas desulfurization on power plants resulted in a significant decline in emissions from the energy sector and stabilization of total Chinese SO2 emissions. Comparable mitigation strategies are not yet present in several other Asian countries and industrial sectors in general, while emissions from international shipping are expected to start declining soon following an international agreement to reduce the sulfur content of fuel oil. The estd. trends in global SO2 emissions are within the range of representative concn. pathway (RCP) projections and the uncertainty previously estd. for the year 2005.
- 49Su, S. S.; Li, B. G.; Cui, S. Y.; Tao, S. Sulfur Dioxide Emissions from Combustion in China: From 1990 to 2007. Environ. Sci. Technol. 2011, 45 (19), 8403– 8410, DOI: 10.1021/es201656fGoogle Scholar49https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3MXhtFWmu7rP&md5=7785e0087833046ebe359711e853d393Sulfur Dioxide Emissions from Combustion in China: From 1990 to 2007Su, Shen-Shen; Li, Beng-Ang; Cui, Si-Yu; Tao, ShuEnvironmental Science & Technology (2011), 45 (19), 8403-8410CODEN: ESTHAG; ISSN:0013-936X. (American Chemical Society)Since 2005, China has become the largest SO2 emitter in the world and aggressive deployment of flue gas desulfurization (FGD) at coal-fired power generating facilities appeared in China when facing the formidable pressure of environment pollution. This work estd. annual SO2 emissions from combustion sources at the Province level in China from 1990 to 2007 using updated data investigations. The method of transportation matrix was used to better understand the coal S content in consuming provinces which improved the inventory. Total combustion-related emissions in 2007 were 28.3 Tg, half of which was contributed by coal-fired power generating facilities. Industrial boiler coal combustion and residential coal consumed for centralized heating were responsible for another 32% of total emissions. From 1990 to 2007, annual SO2 emissions fluctuated with 2 peaks (1996 and 2006); total emissions doubled from 15.4 to 30.8 Tg, at an annual 4.4% growth rate (6.3% since 2000). Due to the extensive use of FGD technol. and the phase-out of small, highly emitting units, SO2 emissions began to decrease after 2006. Differences among literature-reported ests. highlight a great need for addnl. research to reduce uncertainties with more detailed information on key sources and actual device operation.
- 50Zheng, H. T.; Cai, S. Y.; Wang, S. X.; Zhao, B.; Chang, X.; Hao, J. M. Development of a unit-based industrial emission inventory in the Beijing-Tianjin-Hebei region and resulting improvement in air quality modeling. Atmos. Chem. Phys. 2019, 19 (6), 3447– 3462, DOI: 10.5194/acp-19-3447-2019Google Scholar50https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC1MXpt1ynu7s%253D&md5=4b61fefcf1a516822a4c1bd7f4d56db1Development of a unit-based industrial emission inventory in the Beijing-Tianjin-Hebei region and resulting improvement in air quality modelingZheng, Haotian; Cai, Siyi; Wang, Shuxiao; Zhao, Bin; Chang, Xing; Hao, JimingAtmospheric Chemistry and Physics (2019), 19 (6), 3447-3462CODEN: ACPTCE; ISSN:1680-7324. (Copernicus Publications)The Beijing-Tianjin-Hebei (BTH) region is a metropolitan area with the most severe fine particle (PM2.5) pollution in China. An accurate emission inventory plays an important role in air pollution control policy making. In this study, we develop a unit-based emission inventory for industrial sectors in the BTH region, including power plants, industrial boilers, steel, non-ferrous metal smelting, coking plants, cement, glass, brick, lime, ceramics, refineries, and chem. industries, based on detailed information for each enterprise, such as location, annual prodn., prodn. technol./processes, and air pollution control facilities. In the BTH region, the emissions of sulfur dioxide (SO2), nitrogen oxide (NOx), particulate matter with diam. less than 10 μm (PM10), PM2.5, black carbon (BC), org. carbon (OC), and non-methane volatile org. compds. (NMVOCs) from industrial sectors were 869, 1164, 910, 622, 71, 63, and 1390 kt in 2014, resp., accounting for a resp. 61 %, 55 %, 62 %, 56 %, 58 %, 22 %, and 36 % of the total emissions. Compared with the traditional proxy-based emission inventory, much less emissions in the high-resoln. unit-based inventory are allocated to the urban centers due to the accurate positioning of industrial enterprises. We apply the Community Multi-scale Air Quality (CMAQ; version 5.0.2) model simulation to evaluate the unit-based inventory. The simulation results show that the unit-based emission inventory shows better performance with respect to both PM2.5 and gaseous pollutants than the proxy-based emission inventory. The normalized mean biases (NMBs) are 81 %, 21 %, 1 %, and -7 % for the concns. of SO2, NO2, ozone (O3), and PM2.5, resp., with the unit-based inventory, in contrast to 124 %, 39 %, -8 %, and 9 % with the proxy-based inventory; furthermore, the concn. gradients of PM2.5, which are defined as the ratio of the urban concn. to the suburban concn., are 1.6, 2.1, and 1.5 in Jan. and 1.3, 1.5, and 1.3 in July, for simulations with the unit-based inventory, simulations with the proxy-based inventory, and observations, resp., in Beijing. For O3, the corresponding gradients are 0.7, 0.5, and 0.9 in Jan. and 0.9, 0.8, and 1.1 in July, implying that the unit-based emission inventory better reproduces the distributions of pollutant emissions between the urban and suburban areas.
- 51Rohrer, F.; Lu, K. D.; Hofzumahaus, A.; Bohn, B.; Brauers, T.; Chang, C. C.; Fuchs, H.; Haseler, R.; Holland, F.; Hu, M.; Kita, K.; Kondo, Y.; Li, X.; Lou, S. R.; Oebel, A.; Shao, M.; Zeng, L. M.; Zhu, T.; Zhang, Y. H.; Wahner, A. Maximum efficiency in the hydroxyl-radical-based self-cleansing of the troposphere. Nat. Geosci. 2014, 7 (8), 559– 563, DOI: 10.1038/ngeo2199Google Scholar51https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXhtFGqsbjE&md5=6f85b899a8a8d644714c662d6b227355Maximum efficiency in the hydroxyl-radical-based self-cleansing of the troposphereRohrer, Franz; Lu, Keding; Hofzumahaus, Andreas; Bohn, Birger; Brauers, Theo; Chang, Chih-Chung; Fuchs, Hendrik; Haeseler, Rolf; Holland, Frank; Hu, Min; Kita, Kazuyuki; Kondo, Yutaka; Li, Xin; Lou, Shengrong; Oebel, Andreas; Shao, Min; Zeng, Limin; Zhu, Tong; Zhang, Yuanhang; Wahner, AndreasNature Geoscience (2014), 7 (8), 559-563CODEN: NGAEBU; ISSN:1752-0894. (Nature Publishing Group)The removal of trace gases from the troposphere is, in most cases, initialized by reactions with hydroxyl radicals, and the products of these reactions are eventually deposited on the Earth's surface. The concn. of these hydroxyl radicals is therefore a measure of atm. self-cleansing. In theory, hydroxyl-radical concns. can be enhanced by the recycling of some of the reaction products. The only known efficient recycling process involves nitrogen oxide and leads to prodn. of ozone, yet observations in regions with high hydrocarbon and low nitrogen oxide concns. show substantially elevated hydroxyl-radical concns., up to ten times higher than expected. If we normalize obsd. hydroxyl-radical concns. to the max. achievable in model calcns. with variable nitrogen oxide concns., this photochem. coordinate system uncovers a common feature in almost all of these observations: even in the presence of inadequate amts. of nitrogen oxides, hydroxyl-radical concns. are enhanced to the theor. max. obtainable at very much higher nitrogen oxide concns. This means that this important part of the self-cleansing capability of the atm. is working at max. efficiency even in regions with a high burden of biogenic hydrocarbons and low nitrogen oxide concn. Since these processes do not involve nitrogen oxides, tropospheric ozone prodn. is greatly reduced compared with the expectation from current theory.
- 52Lu, K. D.; Rohrer, F.; Holland, F.; Fuchs, H.; Brauers, T.; Oebel, A.; Dlugi, R.; Hu, M.; Li, X.; Lou, S. R.; Shao, M.; Zhu, T.; Wahner, A.; Zhang, Y. H.; Hofzumahaus, A. Nighttime observation and chemistry of HOx in the Pearl River Delta and Beijing in summer 2006. Atmos. Chem. Phys. 2014, 14 (10), 4979– 4999, DOI: 10.5194/acp-14-4979-2014Google Scholar52https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXht1CmtrrM&md5=4475da4c4f59c783c3b444d95dddba8bNighttime observation and chemistry of HOx in the Pearl River Delta and Beijing in summer 2006Lu, K. D.; Rohrer, F.; Holland, F.; Fuchs, H.; Brauers, T.; Oebel, A.; Dlugi, R.; Hu, M.; Li, X.; Lou, S. R.; Shao, M.; Zhu, T.; Wahner, A.; Zhang, Y. H.; Hofzumahaus, A.Atmospheric Chemistry and Physics (2014), 14 (10), 4979-4999, 21 pp.CODEN: ACPTCE; ISSN:1680-7324. (Copernicus Publications)Nighttime HOx chem. was investigated in two ground-based field campaigns (PRIDE-PRD2006 and CAREBEIJING2006) in summer 2006 in China by comparison of measured and modeled concn. data of OH and HO2. The measurement sites were located in a rural environment in the Pearl River Delta (PRD) under urban influence and in a suburban area close to Beijing, resp. In both locations, significant nighttime concns. of radicals were obsd. under conditions with high total OH reactivities of about 40-50 s-1 in PRD and 25 s-1 near Beijing. For OH, the nocturnal concns. were within the range of (0.5-3) × 106 cm-3, implying a significant nighttime oxidn. rate of pollutants on the order of several ppb per h. The measured nighttime concn. of HO2 was about (0.2-5) × 108 cm-3, contg. a significant, model-estd. contribution from RO2 as an interference. A chem. box model based on an established chem. mechanism is capable of reproducing the measured nighttime values of the measured peroxy radicals and kOH, but underestimates in both field campaigns the obsd. OH by about 1 order of magnitude. Sensitivity studies with the box model demonstrate that the OH discrepancy between measured and modeled nighttime OH can be resolved, if an addnl. ROx prodn. process (about 1 ppb h-1) and addnl. recycling (RO2 → HO2 → OH) with an efficiency equiv. to 1 ppb NO is assumed. The addnl. recycling mechanism was also needed to reproduce the OH observations at the same locations during daytime for conditions with NO mixing ratios below 1 ppb. This could be an indication that the same missing process operates at day and night. In principle, the required primary ROx source can be explained by ozonolysis of terpenoids, which react faster with ozone than with OH in the nighttime atm. However, the amt. of these highly reactive biogenic volatile org. compds. (VOCs) would require a strong local source, for which there is no direct evidence. A more likely explanation for an addnl. ROx source is the vertical downward transport of radical reservoir species in the stable nocturnal boundary layer. Using a simplified one-dimensional two-box model, it can be shown that ground-based NO emissions could generate a large vertical gradient causing a downward flux of peroxy acetic nitrate (PAN) and peroxymethacryloyl nitrate (MPAN). The downward transport and the following thermal decompn. of these compds. can produce up to 0.3 ppb h-1 radicals in the atm. layer near the ground. Although this rate is not sufficient to explain the complete OH discrepancy, it indicates the potentially important role of vertical transport in the lower nighttime atm.
- 53Tan, Z.; Fuchs, H.; Lu, K.; Hofzumahaus, A.; Bohn, B.; Broch, S.; Dong, H.; Gomm, S.; Häseler, R.; He, L.; Holland, F.; Li, X.; Liu, Y.; Lu, S.; Rohrer, F.; Shao, M.; Wang, B.; Wang, M.; Wu, Y.; Zeng, L.; Zhang, Y.; Wahner, A.; Zhang, Y. Radical chemistry at a rural site (Wangdu) in the North China Plain: observation and model calculations of OH, HO2 and RO2 radicals. Atmos. Chem. Phys. 2017, 17 (1), 663– 690, DOI: 10.5194/acp-17-663-2017Google Scholar53https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2sXosVCht7s%253D&md5=7771064fa2e60fb9c13aae2534101078Radical chemistry at a rural site (Wangdu) in the North China Plain: observation and model calculations of OH, HO2 and RO2 radicalsTan, Zhaofeng; Fuchs, Hendrik; Lu, Keding; Hofzumahaus, Andreas; Bohn, Birger; Broch, Sebastian; Dong, Huabin; Gomm, Sebastian; Haseler, Rolf; He, Lingyan; Holland, Frank; Li, Xin; Liu, Ying; Lu, Sihua; Rohrer, Franz; Shao, Min; Wang, Baolin; Wang, Ming; Wu, Yusheng; Zeng, Limin; Zhang, Yinsong; Wahner, Andreas; Zhang, YuanhangAtmospheric Chemistry and Physics (2017), 17 (1), 663-690CODEN: ACPTCE; ISSN:1680-7324. (Copernicus Publications)A comprehensive field campaign was carried out in summer 2014 in Wangdu, located in the North China Plain. A month of continuous OH, HO2 and RO2 measurements was achieved. Observations of radicals by the laser-induced fluorescence (LIF) technique revealed daily max. concns. between (5-15) ×106 cm-3, (3-14) ×108 cm-3 and (3-15) ×108 cm-3 for OH, HO2 and RO2, resp. Measured OH reactivities (inverse OH lifetime) were 10 to 20 s-1 during daytime. The chem. box model RACM2, including the Leuven isoprene mechanism (LIM), was used to interpret the obsd. radical concns. As inprevious field campaigns in China, modeled and measured OH concns. agree for NO mixing ratios higher than1 ppbv, but systematic discrepancies are obsd. in the afternoon for NO mixing ratios of less than 300 pptv (themodel-measurement ratio is between 1.4 and 2 in this case).If addnl. OH recycling equiv. to 100 pptv NO is assumed, the model is capable of reproducing the obsd. OH, HO2 and RO2 concns. for conditions of high volatile org. compd. (VOC) and low NOx concns. For HO2, good agreement is found between modelled and obsd. concns. during day and night. In the case of RO2, the agreement between model calcns. and measurements is good in the late afternoon when NO concns. are below 0.3 ppbv. A significant model under prediction of RO2 by a factor of 3 to 5 is found in the morning at NO concns. higher than 1 ppbv, which can be explained by a missing RO2 source of 2 ppbv h-1. As a consequence, the model under predicts the photochem. net ozone prodn. by 20 ppbv per day, which is a significant portion of the daily integrated ozone prodn. (110 ppbv) derived from the measured HO2 and RO2. The addnl. RO2 prodn. from the photolysis of ClNO2 and missing reactivity can explain about 10% and 20% of the discrepancy, resp. The under prediction of the photochem. ozone prodn. at high NOx found in this study is consistent with the results from other field campaigns in urban environments, which underlines the need for better understanding of the peroxy radical chem. for high NOx conditions.
- 54Tan, Z. F.; Rohrer, F.; Lu, K. D.; Ma, X. F.; Bohn, B.; Broch, S.; Dong, H. B.; Fuchs, H.; Gkatzelis, G. I.; Hofzumahaus, A.; Holland, F.; Li, X.; Liu, Y.; Liu, Y. H.; Novelli, A.; Shao, M.; Wang, H. C.; Wu, Y. S.; Zeng, L. M.; Hu, M.; Kiendler-Scharr, A.; Wahner, A.; Zhang, Y. H. Wintertime photochemistry in Beijing: observations of ROx radical concentrations in the North China Plain during the BEST-ONE campaign. Atmos. Chem. Phys. 2018, 18 (16), 12391– 12411, DOI: 10.5194/acp-18-12391-2018Google Scholar54https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC1cXhvFKqtbzE&md5=d83340b3224af51c8a3d6889da7f504cWintertime photochemistry in Beijing: observations of ROx radical concentrations in the North China Plain during the BEST-ONE campaignTan, Zhaofeng; Rohrer, Franz; Lu, Keding; Ma, Xuefei; Bohn, Birger; Broch, Sebastian; Dong, Huabin; Fuchs, Hendrik; Gkatzelis, Georgios I.; Hofzumahaus, Andreas; Holland, Frank; Li, Xin; Liu, Ying; Liu, Yuhan; Novelli, Anna; Shao, Min; Wang, Haichao; Wu, Yusheng; Zeng, Limin; Hu, Min; Kiendler-Scharr, Astrid; Wahner, Andreas; Zhang, YuanhangAtmospheric Chemistry and Physics (2018), 18 (16), 12391-12411CODEN: ACPTCE; ISSN:1680-7324. (Copernicus Publications)The first wintertime in situ measurements of hydroxyl (OH), hydroperoxy (HO2) and org. peroxy (RO2) radicals (ROx = OH + HO2 + RO2) in combination with observations of total reactivity of OH radicals, kOH in Beijing are presented. The field campaign "Beijing winter fine particle STudy - Oxidn., Nucleation and light Extinctions" (BEST-ONE) was conducted at the suburban site Huairou near Beijing from Jan. to March 2016. OH radical concns. at noontime ranged from 2.4 x 106 cm-3 in severely polluted air (kOH ∼ 27 s-1) to 3.6 × 106 cm-3 in relatively clean air (kOH ∼ 5 s-1). These values are nearly 2-fold larger than OH concns. obsd. in previous winter campaigns in Birmingham, Tokyo, and New York City. Other important radical sources were alkene ozonolysis (28%) and photolysis of oxygenated org. compds. (24%). A box model was used to simulate the OH, HO2 and RO2 concns. based on the observations of their long-lived precursors. The model was capable of reproducing the obsd. diurnal variation of the OH and peroxy radicals during clean days with a factor of 1.5. The OH concns. obsd. in the presence of large OH reactivities indicate that atm. trace gas oxidn. by photochem. processes can be highly effective even during wintertime, thereby facilitating the vigorous formation of secondary pollutants.
- 55Lu, K.; Fuchs, H.; Hofzumahaus, A.; Tan, Z.; Wang, H.; Zhang, L.; Schmitt, S. H.; Rohrer, F.; Bohn, B.; Broch, S.; Dong, H.; Gkatzelis, G. I.; Hohaus, T.; Holland, F.; Li, X.; Liu, Y.; Liu, Y.; Ma, X.; Novelli, A.; Schlag, P.; Shao, M.; Wu, Y.; Wu, Z.; Zeng, L.; Hu, M.; Kiendler-Scharr, A.; Wahner, A.; Zhang, Y. Fast Photochemistry in Wintertime Haze: Consequences for Pollution Mitigation Strategies. Environ. Sci. Technol. 2019, 53 (18), 10676– 10684, DOI: 10.1021/acs.est.9b02422Google Scholar55https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC1MXhsFyrurzN&md5=7a4729a7189a2c0bafc3c6c03ef62c38Fast Photochemistry in Wintertime Haze: Consequences for Pollution Mitigation StrategiesLu, Keding; Fuchs, Hendrik; Hofzumahaus, Andreas; Tan, Zhaofeng; Wang, Haichao; Zhang, Lin; Schmitt, Sebastian H.; Rohrer, Franz; Bohn, Birger; Broch, Sebastian; Dong, Huabin; Gkatzelis, Georgios I.; Hohaus, Thorsten; Holland, Frank; Li, Xin; Liu, Ying; Liu, Yuhan; Ma, Xuefei; Novelli, Anna; Schlag, Patrick; Shao, Min; Wu, Yusheng; Wu, Zhijun; Zeng, Limin; Hu, Min; Kiendler-Scharr, Astrid; Wahner, Andreas; Zhang, YuanhangEnvironmental Science & Technology (2019), 53 (18), 10676-10684CODEN: ESTHAG; ISSN:0013-936X. (American Chemical Society)In contrast to summer smog, the contribution of photochem. to the formation of winter haze in northern mid-to-high latitude is generally assumed to be minor due to reduced solar UV and water vapor concns. Our comprehensive observations of atm. radicals and relevant parameters during several haze events in winter 2016 Beijing, however, reveal surprisingly high hydroxyl radical oxidn. rates up to 15 ppbv/h, which is comparable to the high values reported in summer photochem. smog and is two to three times larger than those detd. in previous observations during winter in Birmingham. The active photochem. facilitates the prodn. of secondary pollutants. It is mainly initiated by the photolysis of nitrous acid and ozonolysis of olefins and maintained by an extremely efficiently radical cycling process driven by nitric oxide. This boosted radical recycling generates fast photochem. ozone prodn. rates that are again comparable to those during summer photochem. smog. The formation of ozone, however, is currently masked by its efficient chem. removal by nitrogen oxides contributing to the high level of wintertime particles. The future emission regulations, such as the redn. of nitrogen oxide emissions, therefore are facing the challenge of reducing haze and avoiding an increase in ozone pollution at the same time. Efficient control strategies to mitigate winter haze in Beijing may require measures similar as implemented to avoid photochem. smog in summer.
- 56Srivastava, R. K.; Miller, C. A.; Erickson, C.; Jambhekar, R. Emissions of sulfur trioxide from coal-fired power plants. J. Air Waste Manage. Assoc. 2004, 54 (6), 750– 762, DOI: 10.1080/10473289.2004.10470943Google Scholar56https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD2cXlvFWjtrY%253D&md5=f04d2a848308c69692c247d40e63b2f5Emissions of sulfur trioxide from coal-fired power plantsSrivastava, R. K.; Miller, C. A.; Erickson, C.; Jambhekar, R.Journal of the Air & Waste Management Association (2004), 54 (6), 750-762CODEN: JAWAFC; ISSN:1096-2247. (Air & Waste Management Association)A review concerning air pollution and its control in relation to SO3 and H2SO4 flue gas emissions from coal-fired power generation facilities is given. Topics discussed include: health and environmental effects; impacts on facility hardware; regulatory overview; SO3 formation (in-boiler, in selective catalytic redn. reactors); SO3 depletion or conversion to H2SO4 (processes in air pre-heaters, localized H2SO4 condensation in ducts between air pre-heater and particulate matter control, fly ash H2SO4 adsorption and removal in PM control equipment, aerosol formation in wet flue gas desulfurization systems); SO3 measurement; and mitigating SO3 emissions (alkali addn. to furnace, alkali injection after the furnace, NH3 injection before the electrostatic precipitator, fuel switching and blending, wet electrostatic precipitators, changing air pre-heater operation).
- 57Yang, Z. D.; Zheng, C. H.; Zhang, X. F.; Zhou, H.; Silva, A. A.; Liu, C. Y.; Snyder, B.; Wang, Y.; Gao, X. Challenge of SO3 removal by wet electrostatic precipitator under simulated flue gas with high SO3 concentration. Fuel 2018, 217, 597– 604, DOI: 10.1016/j.fuel.2017.12.125Google Scholar57https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC1cXlvFemsw%253D%253D&md5=9d2b2f6f0fc83fb48e33a3115b527055Challenge of SO3 removal by wet electrostatic precipitator under simulated flue gas with high SO3 concentrationYang, Zhengda; Zheng, Chenghang; Zhang, Xuefeng; Zhou, Hao; Silva, Anthony A.; Liu, Chungyi; Snyder, Bob; Wang, Yi; Gao, XiangFuel (2018), 217 (), 597-604CODEN: FUELAC; ISSN:0016-2361. (Elsevier Ltd.)Wet electrostatic precipitators (WESP) have been proven to be a promising technol. for the removal of sulfuric acid mist from flue gases. Recent studies indicate that WESPs, when mitigating sulfuric acid mist, can be less effective on systems that burn high sulfur content fuel. This paper reports on a pilot-scale WESP used to investigate SO3 removal with high SO3 concn. Both mass concn. of SO3 and no. concn. of sulfuric acid mist were measured. Two key parameters, i.e., elec. characteristics and gas loading, were studied to evaluate their effects on SO3 removal efficiency under severe corona suppression conditions. Results showed that the max. corona current was reduced by 83.1% when the WESP inlet SO3 concn. increased from 0 to 5c0, and the corresponding SO3 removal efficiency decreased from 74.5% to 54.2%. SO3 removal efficiency can be improved by increasing corona power and reducing gas velocity. A comprehensive method was proposed to enhance SO3 removal efficiency, with removal efficiencies greater than 90% using proper electrode configurations and lower velocity under a pilot plant condition. In addn., other challenges including new ultra-fine mist generation, material corrosion and insulator failure are summarized.
- 58Guo, Y.; Yan, C.; Li, C.; Feng, Z.; Zhou, Y.; Lin, Z.; Dada, L.; Stolzenburg, D.; Yin, R.; Kontkanen, J.; Daellenbach, K. R.; Kangasluoma, J.; Yao, L.; Chu, B.; Wang, Y.; Cai, R.; Bianchi, F.; Liu, Y.; Kulmala, M. Atmos. Chem. Phys. Discuss. 2020, DOI: 10.5194/acp-2019-1111Google ScholarThere is no corresponding record for this reference.
- 59Yao, L.; Wang, M.-Y.; Wang, X.-K.; Liu, Y.-J.; Chen, H.-F.; Zheng, J.; Nie, W.; Ding, A.-J.; Geng, F.-H.; Wang, D.-F.; Chen, J.-M.; Worsnop, D. R.; Wang, L. Detection of atmospheric gaseous amines and amides by a high-resolution time-of-flight chemical ionization mass spectrometer with protonated ethanol reagent ions. Atmos. Chem. Phys. 2016, 16 (22), 14527– 14543, DOI: 10.5194/acp-16-14527-2016Google Scholar59https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2sXhs1yhs70%253D&md5=e2444c87a5de006e4001fee14d253b22Detection of atmospheric gaseous amines and amides by a high-resolution time-of-flight chemical ionization mass spectrometer with protonated ethanol reagent ionsYao, Lei; Wang, Ming-Yi; Wang, Xin-Ke; Liu, Yi-Jun; Chen, Hang-Fei; Zheng, Jun; Nie, Wei; Ding, Ai-Jun; Geng, Fu-Hai; Wang, Dong-Fang; Chen, Jian-Min; Worsnop, Douglas R.; Wang, LinAtmospheric Chemistry and Physics (2016), 16 (22), 14527-14543CODEN: ACPTCE; ISSN:1680-7324. (Copernicus Publications)Amines and amides are important atm. org.-nitrogen compds. but high time resoln., highly sensitive, and simultaneous ambient measurements of these species are rather sparse. Here, we present the development of a high-resoln. time-of-flight chem. ionization mass spectrometer (HR-ToF-CIMS) method, utilizing protonated ethanol as reagent ions to simultaneously detect atm. gaseous amines (C1 to C6) and amides (C1 to C6). This method possesses sensitivities of 5.6-19.4 Hz pptv-1 for amines and 3.8-38.0 Hz pptv-1 for amides under total reagent ion signals of ∼ 0.32 MHz. Meanwhile, the detection limits were 0.10-0.50 pptv for amines and 0.29-1.95 pptv for amides at 3σ of the background signal for a 1 min integration time. Controlled characterization in the lab. indicates that relative humidity has significant influences on the detection of amines and amides, whereas the presence of orgs. has no obvious effects. Ambient measurements of amines and amides utilizing this method were conducted from 25 July to 25 August 2015 in urban Shanghai, China. While the concns. of amines ranged from a few parts per trillion by vol. to hundreds of parts per trillion by vol., concns. of amides varied from tens of parts per trillion by vol. to a few ppb by vol. Among the C1- to C6-amines, the C2-amines were the dominant species with concns. up to 130 pptv. For amides, the C3-amides (up to 8.7 ppb) were the most abundant species. The diurnal and backward trajectory anal. profiles of amides suggest that in addn. to the secondary formation of amides in the atm., industrial emissions could be important sources of amides in urban Shanghai. During the campaign, photo-oxidn. of amines and amides might be a main loss pathway for them in daytime, and wet deposition was also an important sink.
- 60Liu, L.; Zhong, J.; Vehkamaki, H.; Kurten, T.; Du, L.; Zhang, X.; Francisco, J. S.; Zeng, X. C. Unexpected quenching effect on new particle formation from the atmospheric reaction of methanol with SO3. Proc. Natl. Acad. Sci. U. S. A. 2019, 116 (50), 24966– 24971, DOI: 10.1073/pnas.1915459116Google Scholar60https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC1MXitl2hurvO&md5=148bbaeaab5d9765173c8b9a242fb57dUnexpected quenching effect on new particle formation from the atmospheric reaction of methanol with SO3Liu, Ling; Zhong, Jie; VehkamAki, Hanna; Kurten, Theo; Du, Lin; Zhang, Xiuhui; Francisco, Joseph S.; Zeng, Xiao ChengProceedings of the National Academy of Sciences of the United States of America (2019), 116 (50), 24966-24971CODEN: PNASA6; ISSN:0027-8424. (National Academy of Sciences)Despite the high abundance in the atm., alcs. in general and methanol in particular are believed to play a small role in atm. new particle formation (NPF) largely due to the weak binding abilities of alcs. with the major nucleation precursors, e.g., sulfuric acid (SA) and dimethylamine (DMA). Herein, we identify a catalytic reaction that was previously overlooked, namely, the reaction between methanol and SO3, catalyzed by SA, DMA, or water. We found that alcs. can have unexpected quenching effects on the NPF process, particularly in dry and highly polluted regions with high concns. of alcs. Specifically, the catalytic reaction between methanol and SO3 can convert methanol into a less-volatile species-Me hydrogen sulfate (MHS). The latter was initially thought to be a good nucleation agent for NPF. However, our simulation results suggest that the formation of MHS consumes an appreciable amt. of atm. SO3, disfavoring further reactions of SO3 with H2O. Indeed, we found that MHS formation can cause a redn. of SA concn. up to 87%, whereas the nucleation ability of MHS toward new particles is not as good as that of SA. Hence, a high abundance of methanol in the atm. can lower the particle nucleation rate by as much as two orders of magnitude. Such a quenching effect suggests that the recently identified catalytic reactions between alcs. and SO3 need to be considered in atm. modeling to predict SA concn. from SO2, while also account for their potentially neg. effect on NPF.
- 61Olin, M.; Kuuluvainen, H.; Aurela, M.; Kalliokoski, J.; Kuittinen, N.; Isotalo, M.; Timonen, H. J.; Niemi, J. V.; Rönkkö, T.; Dal Maso, M. Traffic-originated nanocluster emission exceeds H2SO4-driven photochemical new particle formation in an urban area. Atmos. Chem. Phys. 2020, 20 (1), 1– 13, DOI: 10.5194/acp-20-1-2020Google Scholar61https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB3cXhsVCqsLw%253D&md5=999fb2cb0529e50178519c93b5dd7363Traffic-originated nanocluster emission exceeds H2SO4-driven photochemical new particle formation in an urban areaOlin, Miska; Kuuluvainen, Heino; Aurela, Minna; Kalliokoski, Joni; Kuittinen, Niina; Isotalo, Mia; Timonen, Hilkka J.; Niemi, Jarkko V.; Ronkko, Topi; Dal Maso, MiikkaAtmospheric Chemistry and Physics (2020), 20 (1), 1-13CODEN: ACPTCE; ISSN:1680-7324. (Copernicus Publications)Elevated ambient concns. of sub-3nm particles (nanocluster aerosol, NCA) are generally related to atm. new particle formation events, usually linked with gaseous sulfuric acid (H2SO4) produced via photochem. oxidn. of sulfur dioxide. According to our measurement results of H2SO4 and NCA concns., traffic d., and solar irradiance at an urban traffic site in Helsinki, Finland, the view of aerosol formation in traffic-influenced environments is updated by presenting two sep. and independent pathways of traffic affecting the atm. NCA concns.: by acting as a direct nanocluster source and by influencing the prodn. of H2SO4. Urban aerosol formation studies should, therefore, be updated to include the proposed formation mechanisms. The formation of H2SO4 in urban environments is here sepd. into two routes: primary H2SO4 is formed in hot vehicle exhaust and is converted rapidly to the particle phase; secondary H2SO4 results from the combined effect of emitted gaseous precursors and available solar radiation. A rough estn. demonstrates that ∼85% of the total NCA and ∼68% of the total H2SO4 in urban air at noontime at the measurement site are contributed by traffic, indicating the importance of traffic emissions.
- 62Ronkko, T.; Kuuluvainen, H.; Karjalainen, P.; Keskinen, J.; Hillamo, R.; Niemi, J. V.; Pirjola, L.; Timonen, H. J.; Saarikoski, S.; Saukko, E.; Jarvinen, A.; Silvennoinen, H.; Rostedt, A.; Olin, M.; Yli-Ojanpera, J.; Nousiainen, P.; Kousa, A.; Dal Maso, M. Traffic is a major source of atmospheric nanocluster aerosol. Proc. Natl. Acad. Sci. U. S. A. 2017, 114 (29), 7549– 7554, DOI: 10.1073/pnas.1700830114Google Scholar62https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2sXhtFSmtrbK&md5=d763b6f8f4d0abfbfe8372de8ca272ffTraffic is a major source of atmospheric nanocluster aerosolRonkko, Topi; Kuuluvainen, Heino; Karjalainen, Panu; Keskinen, Jorma; Hillamo, Risto; Niemi, Jarkko V.; Pirjola, Liisa; Timonen, Hilkka J.; Saarikoski, Sanna; Saukko, Erkka; Jarvinen, Anssi; Silvennoinen, Henna; Rostedt, Antti; Olin, Miska; Yli-Ojanpera, Jaakko; Nousiainen, Pekka; Kousa, Anu; Dal Maso, MiikkaProceedings of the National Academy of Sciences of the United States of America (2017), 114 (29), 7549-7554CODEN: PNASA6; ISSN:0027-8424. (National Academy of Sciences)In densely populated areas, traffic is a significant source of atm. aerosol particles. Owing to their small size and complicated chem. and phys. characteristics, atm. particles resulting from traffic emissions pose a significant risk to human health and also contribute to anthropogenic forcing of climate. Previous research has established that vehicles directly emit primary aerosol particles and also contribute to secondary aerosol particle formation by emitting aerosol precursors. Here, we extend the urban atm. aerosol characterization to cover nanocluster aerosol (NCA) particles and show that a major fraction of particles emitted by road transportation are in a previously unmeasured size range of 1.3-3.0 nm. For instance, in a semiurban roadside environment, the NCA represented 20-54% of the total particle concn. in ambient air. The obsd. NCA concns. varied significantly depending on the traffic rate and wind direction. The emission factors of NCA for traffic were 2.4·1015 (kgfuel)-1 in a roadside environment, 2.6·1015 (kgfuel)-1 in a street canyon, and 2.9·1015 (kgfuel)-1 in an on-road study throughout Europe. Interestingly, these emissions were not assocd. with all vehicles. In engine lab. expts., the emission factor of exhaust NCA varied from a relatively low value of 1.6·1012 (kgfuel)-1 to a high value of 4.3·1015 (kgfuel)-1. These NCA emissions directly affect particle concns. and human exposure to nanosized aerosol in urban areas, and potentially may act as nanosized condensation nuclei for the condensation of atm. low-volatile org. compds.
Cited By
Click to copy section linkSection link copied!
This article is cited by 35 publications.
- Peng Zhang, Hao Li, Shuying Wang, Biwu Chu, Tianzeng Chen, Qingxin Ma, Yonghong Wang, Yunbo Yu, Hong He. Dark NO2 Reduction on a Graphene Surface with Implications for Soot Aging and HONO Formation. Environmental Science & Technology 2024, 58
(38)
, 16931-16940. https://doi.org/10.1021/acs.est.4c03406
- Avinash Kumar, Siddharth Iyer, Shawon Barua, James Brean, Emin Besic, Prasenjit Seal, Manuel Dall’Osto, David C. S. Beddows, Nina Sarnela, Tuija Jokinen, Mikko Sipilä, Roy M. Harrison, Matti Rissanen. Direct Measurements of Covalently Bonded Sulfuric Anhydrides from Gas-Phase Reactions of SO3 with Acids under Ambient Conditions. Journal of the American Chemical Society 2024, 146
(22)
, 15562-15575. https://doi.org/10.1021/jacs.4c04531
- James M. Mattila, Jonathan D. Krug, William R. Roberson, R. Preston Burnette, Stella McDonald, Larry Virtaranta, John H. Offenberg, William P. Linak. Characterizing Volatile Emissions and Combustion Byproducts from Aqueous Film-Forming Foams Using Online Chemical Ionization Mass Spectrometry. Environmental Science & Technology 2024, 58
(8)
, 3942-3952. https://doi.org/10.1021/acs.est.3c09255
- Qianru Zhang, Yuhang Wang, Maodian Liu, Mingming Zheng, Lianxin Yuan, Junfeng Liu, Shu Tao, Xuejun Wang. Wintertime Formation of Large Sulfate Particles in China and Implications for Human Health. Environmental Science & Technology 2023, 57
(48)
, 20010-20023. https://doi.org/10.1021/acs.est.3c05645
- Yajuan Feng, Chao Wang. Surface Confinement of Finite-Size Water Droplets for SO3 Hydrolysis Reaction Revealed by Molecular Dynamics Simulations Based on a Machine Learning Force Field. Journal of the American Chemical Society 2023, 145
(19)
, 10631-10640. https://doi.org/10.1021/jacs.3c00698
- Bo Long, Yu Xia, Junwei Lucas Bao, Javier Carmona-García, Juan Carlos Gómez Martín, John M. C. Plane, Alfonso Saiz-Lopez, Daniel Roca-Sanjuán, Joseph S. Francisco. Reaction of SO3 with HONO2 and Implications for Sulfur Partitioning in the Atmosphere. Journal of the American Chemical Society 2022, 144
(20)
, 9172-9177. https://doi.org/10.1021/jacs.2c03499
- Torsten Berndt. Peroxy Radical Processes and Product Formation in the OH Radical-Initiated Oxidation of α-Pinene for Near-Atmospheric Conditions. The Journal of Physical Chemistry A 2021, 125
(41)
, 9151-9160. https://doi.org/10.1021/acs.jpca.1c05576
- Haijie Zhang, Wei Wang, Liang Fan, Junling Li, Yanqin Ren, Hong Li, Rui Gao, Yisheng Xu. The role of sulfur cycle in new particle formation: Cycloaddition reaction of SO3 to H2S. Journal of Environmental Sciences 2025, 148 , 489-501. https://doi.org/10.1016/j.jes.2023.09.010
- Qiao Gao, Zegang Dong, Bo Long. Reactions of sulfur trioxide with hypochlorous acid catalyzed by water in gas phase and at the air-water nanodroplet interface in the atmosphere: An important sink for hypochlorous acid. Atmospheric Environment 2024, 331 , 120574. https://doi.org/10.1016/j.atmosenv.2024.120574
- Ruonan Fan, Yingying Ma, Wenxiang Cao, Shikuan Jin, Boming Liu, Weiyan Wang, Hui Li, Wei Gong. New insights into black carbon light absorption enhancement: A comprehensive analysis of two differential behaviors. Environmental Pollution 2024, 355 , 124175. https://doi.org/10.1016/j.envpol.2024.124175
- Xi Zhang, Jiarong Chen, Bo Long. Atmospheric reactions of hydroperoxymethyl thioformate with sulfur trioxide catalyzed by water monomer and hydrolysis of sulfur trioxide catalyzed by hydroperoxymethyl thioformate. Computational and Theoretical Chemistry 2024, 1237 , 114641. https://doi.org/10.1016/j.comptc.2024.114641
- Tianzeng Chen, Yanli Ge, Biwu Chu, Peng Zhang, Qingxin Ma, Hong He. Applications of environmental mass spectrometry in atmospheric haze chemistry. TrAC Trends in Analytical Chemistry 2024, 172 , 117614. https://doi.org/10.1016/j.trac.2024.117614
- Zihao Zhang, Haiwei Li, Wingkei Ho, Long Cui, Qihui Men, Li Cao, Yunjiang Zhang, Junfeng Wang, Cheng Huang, Shun-cheng Lee, Yu Huang, Mindong Chen, Xinlei Ge. Critical Roles of Surface-Enhanced Heterogeneous Oxidation of SO2 in Haze Chemistry: Review of Extended Pathways for Complex Air Pollution. Current Pollution Reports 2024, 10
(1)
, 70-86. https://doi.org/10.1007/s40726-023-00287-2
- Sakshi Gupta, Shobhna Shankar, Jagdish Chandra Kuniyal, Priyanka Srivastava, Renu Lata, Sheetal Chaudhary, Isha Thakur, Archana Bawari, Shilpa Thakur, Monami Dutta, Abhinandan Ghosh, Manish Naja, Abhijit Chatterjee, Ranu Gadi, Nikki Choudhary, Akansha Rai, Sudhir Kumar Sharma. Identification of sources of coarse mode aerosol particles (PM10) using ATR-FTIR and SEM-EDX spectroscopy over the Himalayan Region of India. Environmental Science and Pollution Research 2024, 31
(10)
, 15788-15808. https://doi.org/10.1007/s11356-024-31973-3
- Xiaomeng Zhang, Yongjian Lian, Shendong Tan, Shi Yin. Organosulfate produced from consumption of SO
3
speeds up sulfuric acid–dimethylamine atmospheric nucleation. Atmospheric Chemistry and Physics 2024, 24
(6)
, 3593-3612. https://doi.org/10.5194/acp-24-3593-2024
- Rui Wang, Yang Cheng, Shasha Chen, Rongrong Li, Yue Hu, Xiaokai Guo, Tianlei Zhang, Fengmin Song, Hao Li. Reaction of SO
3
with H
2
SO
4
and its implications for aerosol particle formation in the gas phase and at the air–water interface. Atmospheric Chemistry and Physics 2024, 24
(7)
, 4029-4046. https://doi.org/10.5194/acp-24-4029-2024
- Dandan Wu, Aling Ma, Zhiyi Liu, Zhenzhen Wang, Fang Xu, Guohong Fan, Hong Xu. Adsorption of sulfur-containing contaminant gases by pristine, Cr and Mo doped NbS
2
monolayers based on density functional theory. Nanotechnology 2023, 34
(50)
, 505708. https://doi.org/10.1088/1361-6528/acfb13
- Torsten Berndt, Erik H. Hoffmann, Andreas Tilgner, Frank Stratmann, Hartmut Herrmann. Direct sulfuric acid formation from the gas-phase oxidation of reduced-sulfur compounds. Nature Communications 2023, 14
(1)
https://doi.org/10.1038/s41467-023-40586-2
- Sadashiv Chaturvedi, Amit Kumar, Varsha Singh, Biswameet Chakraborty, Rupesh Kumar, Liu Min. Recent Advancement in Organic Aerosol Understanding: a Review of Their Sources, Formation, and Health Impacts. Water, Air, & Soil Pollution 2023, 234
(12)
https://doi.org/10.1007/s11270-023-06772-0
- Yuchen Wang, Shumin Liang, Michael Le Breton, Qiong Qiong Wang, Qianyun Liu, Chin Hung Ho, Bin Yu Kuang, Cheng Wu, Mattias Hallquist, Rongbiao Tong, Jian Zhen Yu. Field observations of C2 and C3 organosulfates and insights into their formation mechanisms at a suburban site in Hong Kong. Science of The Total Environment 2023, 904 , 166851. https://doi.org/10.1016/j.scitotenv.2023.166851
- Qingxin Ma, Chunyan Zhang, Chang Liu, Guangzhi He, Peng Zhang, Hao Li, Biwu Chu, Hong He. A review on the heterogeneous oxidation of SO
2
on solid atmospheric particles: Implications for sulfate formation in haze chemistry. Critical Reviews in Environmental Science and Technology 2023, 53
(21)
, 1888-1911. https://doi.org/10.1080/10643389.2023.2190315
- Haijie Zhang, Rui Gao, Hong Li, Yunfeng Li, Yisheng Xu, Fahe Chai. Formation mechanism of typical aromatic sulfuric anhydrides and their potential role in atmospheric nucleation process. Journal of Environmental Sciences 2023, 123 , 54-64. https://doi.org/10.1016/j.jes.2022.01.015
- Fei Xie, Yue Su, Yongli Tian, Yanju Shi, Xingjun Zhou, Peng Wang, Ruihong Yu, Wei Wang, Jiang He, Jinyuan Xin, Changwei Lü. The shifting of secondary inorganic aerosol formation mechanisms during haze aggravation: the decisive role of aerosol liquid water. Atmospheric Chemistry and Physics 2023, 23
(4)
, 2365-2378. https://doi.org/10.5194/acp-23-2365-2023
- Jing Cai, Kaspar R. Daellenbach, Cheng Wu, Yan Zheng, Feixue Zheng, Wei Du, Sophie L. Haslett, Qi Chen, Markku Kulmala, Claudia Mohr. Characterization of offline analysis of particulate matter with FIGAERO-CIMS. Atmospheric Measurement Techniques 2023, 16
(5)
, 1147-1165. https://doi.org/10.5194/amt-16-1147-2023
- Stanley Ou, Jessica E. Heimann, Joseph W. Bennett. A Density Functional Theory (DFT) Investigation of Sulfur-Based Adsorbate Interactions on Alumina and Calcite Surfaces. Clays and Clay Minerals 2022, 70
(3)
, 370-385. https://doi.org/10.1007/s42860-022-00194-5
- A. Suvitha, N. S. Venkataramanan, R. Sahara. Effect of water molecule in the structure, stability, and electronic properties of sulfur trioxide clusters: a computational analysis. Monatshefte für Chemie - Chemical Monthly 2022, 153
(4)
, 347-357. https://doi.org/10.1007/s00706-022-02909-9
- Haijie Zhang, Wei Wang, Hong Li, Rui Gao, Yisheng Xu. A theoretical study on the formation mechanism of carboxylic sulfuric anhydride and its potential role in new particle formation. RSC Advances 2022, 12
(9)
, 5501-5508. https://doi.org/10.1039/D2RA00226D
- Xingyu Pang, Wei Liu, Haomiao Xu, Qinyuan Hong, Peng Cui, Wenjun Huang, Zan Qu, Naiqiang Yan. Selective uptake of gaseous sulfur trioxide and mercury in ZnO-CuS composite at elevated temperatures from SO2-rich flue gas. Chemical Engineering Journal 2022, 427 , 132035. https://doi.org/10.1016/j.cej.2021.132035
- Jing Cai, Cheng Wu, Jiandong Wang, Wei Du, Feixue Zheng, Simo Hakala, Xiaolong Fan, Biwu Chu, Lei Yao, Zemin Feng, Yongchun Liu, Yele Sun, Jun Zheng, Chao Yan, Federico Bianchi, Markku Kulmala, Claudia Mohr, Kaspar R. Daellenbach. Influence of organic aerosol molecular composition on particle absorptive properties in autumn Beijing. Atmospheric Chemistry and Physics 2022, 22
(2)
, 1251-1269. https://doi.org/10.5194/acp-22-1251-2022
- Xiaolong Fan, Jing Cai, Chao Yan, Jian Zhao, Yishuo Guo, Chang Li, Kaspar R. Dällenbach, Feixue Zheng, Zhuohui Lin, Biwu Chu, Yonghong Wang, Lubna Dada, Qiaozhi Zha, Wei Du, Jenni Kontkanen, Theo Kurtén, Siddhart Iyer, Joni T. Kujansuu, Tuukka Petäjä, Douglas R. Worsnop, Veli-Matti Kerminen, Yongchun Liu, Federico Bianchi, Yee Jun Tham, Lei Yao, Markku Kulmala. Atmospheric gaseous hydrochloric and hydrobromic acid in urban Beijing, China: detection, source identification and potential atmospheric impacts. Atmospheric Chemistry and Physics 2021, 21
(14)
, 11437-11452. https://doi.org/10.5194/acp-21-11437-2021
- Yongchun Liu, Zemin Feng, Feixue Zheng, Xiaolei Bao, Pengfei Liu, Yanli Ge, Yan Zhao, Tao Jiang, Yunwen Liao, Yusheng Zhang, Xiaolong Fan, Chao Yan, Biwu Chu, Yonghong Wang, Wei Du, Jing Cai, Federico Bianchi, Tuukka Petäjä, Yujing Mu, Hong He, Markku Kulmala. Ammonium nitrate promotes sulfate formation through uptake kinetic regime. Atmospheric Chemistry and Physics 2021, 21
(17)
, 13269-13286. https://doi.org/10.5194/acp-21-13269-2021
- Alexandre Kukui, Michel Chartier, Jinhe Wang, Hui Chen, Sébastien Dusanter, Stéphane Sauvage, Vincent Michoud, Nadine Locoge, Valérie Gros, Thierry Bourrianne, Karine Sellegri, Jean-Marc Pichon. Role of Criegee intermediates in the formation of sulfuric acid at a Mediterranean (Cape Corsica) site under influence of biogenic emissions. Atmospheric Chemistry and Physics 2021, 21
(17)
, 13333-13351. https://doi.org/10.5194/acp-21-13333-2021
- Ying Zhou, Simo Hakala, Chao Yan, Yang Gao, Xiaohong Yao, Biwu Chu, Tommy Chan, Juha Kangasluoma, Shahzad Gani, Jenni Kontkanen, Pauli Paasonen, Yongchun Liu, Tuukka Petäjä, Markku Kulmala, Lubna Dada. Measurement report: New particle formation characteristics at an urban and a mountain station in northern China. Atmospheric Chemistry and Physics 2021, 21
(23)
, 17885-17906. https://doi.org/10.5194/acp-21-17885-2021
- Yishuo Guo, Chao Yan, Chang Li, Wei Ma, Zemin Feng, Ying Zhou, Zhuohui Lin, Lubna Dada, Dominik Stolzenburg, Rujing Yin, Jenni Kontkanen, Kaspar R. Daellenbach, Juha Kangasluoma, Lei Yao, Biwu Chu, Yonghong Wang, Runlong Cai, Federico Bianchi, Yongchun Liu, Markku Kulmala. Formation of nighttime sulfuric acid from the ozonolysis of alkenes in Beijing. Atmospheric Chemistry and Physics 2021, 21
(7)
, 5499-5511. https://doi.org/10.5194/acp-21-5499-2021
- Lubna Dada, Ilona Ylivinkka, Rima Baalbaki, Chang Li, Yishuo Guo, Chao Yan, Lei Yao, Nina Sarnela, Tuija Jokinen, Kaspar R. Daellenbach, Rujing Yin, Chenjuan Deng, Biwu Chu, Tuomo Nieminen, Yonghong Wang, Zhuohui Lin, Roseline C. Thakur, Jenni Kontkanen, Dominik Stolzenburg, Mikko Sipilä, Tareq Hussein, Pauli Paasonen, Federico Bianchi, Imre Salma, Tamás Weidinger, Michael Pikridas, Jean Sciare, Jingkun Jiang, Yongchun Liu, Tuukka Petäjä, Veli-Matti Kerminen, Markku Kulmala. Sources and sinks driving sulfuric acid concentrations in contrasting environments: implications on proxy calculations. Atmospheric Chemistry and Physics 2020, 20
(20)
, 11747-11766. https://doi.org/10.5194/acp-20-11747-2020
Learn about these metrics
Article Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.
Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.
The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated.
Recommended Articles
Abstract
Figure 1
Figure 1. (A) Time series of SO3 during the winter (January 20 to March 31, 2019) and summer (June 1 to July 10, 2019), (B) median diurnal patterns of SO3, UVB, and atmospheric water dimer concentrations during the winter and summer, and (C) median normalized intensities of the atmospheric ion SO3·NO3–. Rainy and snowy days were excluded. The shadows show the values from the 25th to 75th percentile. In panel B, the dashed lines show diurnal variations of SO3 during haze and nonhaze days. The water dimer concentration was calculated on the basis of temperature and relative humidity. (26,39) In panel C, the signals of atmospheric ion SO3·NO3– were normalized by the sum of NO3– and HNO3·NO3– that are dominant natural charged ions in urban Beijing (Figure S7).
Figure 2
Figure 2. (A) Median diurnal variations in the concentrations of SO3, SO2, black carbon (BC), NOx, the approximate abundance term {([BC][SO2])/[(H2O)2]} of SO3, and gasoline and diesel vehicle flow of the “West Third Ring Road”, which was ∼550 m to the west of the sampling station in 2017, (41) and (B) correlation between the SO3 concentration and its approximate abundance term during the night and the early morning (from 18:00 to 08:00 the next day) for the whole field measurement during the winter. In panel A, the units of BC, SO2, and water dimer [(H2O)2] in approximate source terms were micrograms per cubic meter, molecules per cubic meter, and molecules per cubic meter, respectively. In panel B, the SO3 concentrations were divided into logarithmic bins, and the median values in each bin are shown as squares. The orange shadow represents the values from the 25th to 75th percentile.
Figure 3
Figure 3. Median diurnal variations in the concentrations and intensities of SO3, the sulfuric acid (SA) monomer (H2SO4) and dimer, sub-2.5 nm particles, SO2, O3, UVB, and condensation sink (CS) during the (A) winter and (B) summer.
References
This article references 62 other publications.
- 1Larssen, T.; Lydersen, E.; Tang, D. G.; He, Y.; Gao, J. X.; Liu, H. Y.; Duan, L.; Seip, H. M.; Vogt, R. D.; Mulder, J.; Shao, M.; Wang, Y. H.; Shang, H.; Zhang, X. S.; Solberg, S.; Aas, W.; Okland, T.; Eilertsen, O.; Angell, V.; Li, Q. R.; Zhao, D. W.; Xiang, R. J.; Xiao, J. S.; Luo, J. H. Acid rain in China. Environ. Sci. Technol. 2006, 40 (2), 418– 425, DOI: 10.1021/es06261331https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD28XmsVSltA%253D%253D&md5=7fb8980553c6c7c404a7e13d24f6e819Acid rain in ChinaLarssen, Thorjorn; Lydersen, Espen; Tang, Dagang; He, Yi; Gao, Jixi; Liu, Haiying; Duan, Lei; Seip, Hans M.; Vogt, Rolf D.; Mulder, Jan; Shao, Min; Wang, Yanhui; Shang, He; Zhang, Xiaoshan; Solberg, Svein; Aas, Wenche; Okland, Tonje; Eilertsen, Odd; Angell, Valter; Liu, Quanru; Zhao, Dawei; Xiang, Renjun; Xiao, Jinshong; Luo, JiahaiEnvironmental Science and Technology (2006), 40 (2), 418-425CODEN: ESTHAG; ISSN:0013-936X. (American Chemical Society)There is no expanded citation for this reference.
- 2Sipilä, M.; Berndt, T.; Petäjä, T.; Brus, D.; Vanhanen, J.; Stratmann, F.; Patokoski, J.; Mauldin, R. L.; Hyvarinen, A. P.; Lihavainen, H.; Kulmala, M. The Role of Sulfuric Acid in Atmospheric Nucleation. Science 2010, 327 (5970), 1243– 1246, DOI: 10.1126/science.11803152https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A280%3ADC%252BC3c7lvFWiug%253D%253D&md5=e091ca63c1c073ce1f5c63fc0db03d53The role of sulfuric acid in atmospheric nucleationSipila Mikko; Berndt Torsten; Petaja Tuukka; Brus David; Vanhanen Joonas; Stratmann Frank; Patokoski Johanna; Mauldin Roy L 3rd; Hyvarinen Antti-Pekka; Lihavainen Heikki; Kulmala MarkkuScience (New York, N.Y.) (2010), 327 (5970), 1243-6 ISSN:.Nucleation is a fundamental step in atmospheric new-particle formation. However, laboratory experiments on nucleation have systematically failed to demonstrate sulfuric acid particle formation rates as high as those necessary to account for ambient atmospheric concentrations, and the role of sulfuric acid in atmospheric nucleation has remained a mystery. Here, we report measurements of new particles (with diameters of approximately 1.5 nanometers) observed immediately after their formation at atmospherically relevant sulfuric acid concentrations. Furthermore, we show that correlations between measured nucleation rates and sulfuric acid concentrations suggest that freshly formed particles contain one to two sulfuric acid molecules, a number consistent with assumptions that are based on atmospheric observations. Incorporation of these findings into global models should improve the understanding of the impact of secondary particle formation on climate.
- 3Kulmala, M.; Kontkanen, J.; Junninen, H.; Lehtipalo, K.; Manninen, H. E.; Nieminen, T.; Petäjä, T.; Sipilä, M.; Schobesberger, S.; Rantala, P.; Franchin, A.; Jokinen, T.; Jarvinen, E.; Aijala, M.; Kangasluoma, J.; Hakala, J.; Aalto, P. P.; Paasonen, P.; Mikkila, J.; Vanhanen, J.; Aalto, J.; Hakola, H.; Makkonen, U.; Ruuskanen, T.; Mauldin, R. L.; Duplissy, J.; Vehkamaki, H.; Back, J.; Kortelainen, A.; Riipinen, I.; Kurtén, T.; Johnston, M. V.; Smith, J. N.; Ehn, M.; Mentel, T. F.; Lehtinen, K. E.; Laaksonen, A.; Kerminen, V. M.; Worsnop, D. R. Direct observations of atmospheric aerosol nucleation. Science 2013, 339 (6122), 943– 6, DOI: 10.1126/science.12273853https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXis1Oisb4%253D&md5=1d1f6dd3764359aeb7515f9c57bcf270Direct Observations of Atmospheric Aerosol NucleationKulmala, Markku; Kontkanen, Jenni; Junninen, Heikki; Lehtipalo, Katrianne; Manninen, Hanna E.; Nieminen, Tuomo; Petaejae, Tuukka; Sipilae, Mikko; Schobesberger, Siegfried; Rantala, Pekka; Franchin, Alessandro; Jokinen, Tuija; Jaervinen, Emma; Aeijaelae, Mikko; Kangasluoma, Juha; Hakala, Jani; Aalto, Pasi P.; Paasonen, Pauli; Mikkilae, Jyri; Vanhanen, Joonas; Aalto, Juho; Hakola, Hannele; Makkonen, Ulla; Ruuskanen, Taina; Mauldin, Roy L., III; Duplissy, Jonathan; Vehkamaeki, Hanna; Baeck, Jaana; Kortelainen, Aki; Riipinen, Ilona; Kurten, Theo; Johnston, Murray V.; Smith, James N.; Ehn, Mikael; Mentel, Thomas F.; Lehtinen, Kari E. J.; Laaksonen, Ari; Kerminen, Veli-Matti; Worsnop, Douglas R.Science (Washington, DC, United States) (2013), 339 (6122), 943-946CODEN: SCIEAS; ISSN:0036-8075. (American Association for the Advancement of Science)Atm. nucleation is the dominant source of aerosol particles in the global atm. and an important player in aerosol climate effects. Key steps of this process occur in the sub-2-nm (nm) size range, in which direct size-segregated observations have not been possible until very recently. This work presents detailed observations of atm. nanoparticles and clusters down to 1-nm mobility diam. It identified 3 sep. size regimes <2-nm diam. which build up a phys., chem., and dynamically consistent framework on atm. nucleation; more specifically, aerosol formation via neutral pathways. Results emphasize the important role of org. compds. in atm. aerosol formation, subsequent aerosol growth, radiative forcing, and assocd. feedbacks among biogenic emissions, clouds, and climate.
- 4Bianchi, F.; Tröstl, J.; Junninen, H.; Frege, C.; Henne, S.; Hoyle, C. R.; Molteni, U.; Herrmann, E.; Adamov, A.; Bukowiecki, N.; Chen, X.; Duplissy, J.; Gysel, M.; Hutterli, M.; Kangasluoma, J.; Kontkanen, J.; Kurten, A.; Manninen, H. E.; Munch, S.; Perakyla, O.; Petäjä, T.; Rondo, L.; Williamson, C.; Weingartner, E.; Curtius, J.; Worsnop, D. R.; Kulmala, M.; Dommen, J.; Baltensperger, U. New particle formation in the free troposphere: A question of chemistry and timing. Science 2016, 352 (6289), 1109– 1112, DOI: 10.1126/science.aad54564https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC28XosValsL4%253D&md5=c8c6c51f81628a151c131d83c3baa086New particle formation in the free troposphere: A question of chemistry and timingBianchi, F.; Troestl, J.; Junninen, H.; Frege, C.; Henne, S.; Hoyle, C. R.; Molteni, U.; Herrmann, E.; Adamov, A.; Bukowiecki, N.; Chen, X.; Duplissy, J.; Gysel, M.; Hutterli, M.; Kangasluoma, J.; Kontkanen, J.; Kuerten, A.; Manninen, H. E.; Muench, S.; Peraekylae, O.; Petaejae, T.; Rondo, L.; Williamson, C.; Weingartner, E.; Curtius, J.; Worsnop, D. R.; Kulmala, M.; Dommen, J.; Baltensperger, U.Science (Washington, DC, United States) (2016), 352 (6289), 1109-1112CODEN: SCIEAS; ISSN:0036-8075. (American Association for the Advancement of Science)New particle formation (NPF) is the source of over half of the atm.'s cloud condensation nuclei, thus influencing cloud properties and Earth's energy balance. Unlike in the planetary boundary layer, few observations of NPF in the free troposphere exist. The authors provided observational evidence that at high altitudes, NPF occurs mainly through condensation of highly oxygenated mols. (HOMs), in addn. to taking place through sulfuric acid-ammonia nucleation. Neutral nucleation is more than 10 times faster than ion-induced nucleation, and growth rates are size-dependent. NPF is restricted to a time window of 1 to 2 days after contact of the air masses with the planetary boundary layer; this is related to the time needed for oxidn. of org. compds. to form HOMs. These findings require improved NPF parameterization in atm. models.
- 5Yao, L.; Garmash, O.; Bianchi, F.; Zheng, J.; Yan, C.; Kontkanen, J.; Junninen, H.; Mazon, S. B.; Ehn, M.; Paasonen, P.; Sipilä, M.; Wang, M.; Wang, X.; Xiao, S.; Chen, H.; Lu, Y.; Zhang, B.; Wang, D.; Fu, Q.; Geng, F.; Li, L.; Wang, H.; Qiao, L.; Yang, X.; Chen, J.; Kerminen, V. M.; Petäjä, T.; Worsnop, D. R.; Kulmala, M.; Wang, L. Atmospheric new particle formation from sulfuric acid and amines in a Chinese megacity. Science 2018, 361 (6399), 278– 281, DOI: 10.1126/science.aao48395https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC1cXhtlantbvK&md5=1416423dc9523bfe945710d98ffc9b13Atmospheric new particle formation from sulfuric acid and amines in a Chinese megacityYao, Lei; Garmash, Olga; Bianchi, Federico; Zheng, Jun; Yan, Chao; Kontkanen, Jenni; Junninen, Heikki; Mazon, Stephany Buenrostro; Ehn, Mikael; Paasonen, Pauli; Sipilae, Mikko; Wang, Mingyi; Wang, Xinke; Xiao, Shan; Chen, Hangfei; Lu, Yiqun; Zhang, Bowen; Wang, Dongfang; Fu, Qingyan; Geng, Fuhai; Li, Li; Wang, Hongli; Qiao, Liping; Yang, Xin; Chen, Jianmin; Kerminen, Veli-Matti; Petaejae, Tuukka; Worsnop, Douglas R.; Kulmala, Markku; Wang, LinScience (Washington, DC, United States) (2018), 361 (6399), 278-281CODEN: SCIEAS; ISSN:0036-8075. (American Association for the Advancement of Science)Atm. new particle formation (NPF) is an important global phenomenon that is nevertheless sensitive to ambient conditions. According to both observation and theor. arguments, NPF usually requires a relatively high sulfuric acid (H2SO4) concn. to promote the formation of new particles and a low preexisting aerosol loading to minimize the sink of new particles. We investigated NPF in Shanghai and were able to observe both precursor vapors (H2SO4) and initial clusters at a mol. level in a megacity. High NPF rates were obsd. to coincide with several familiar markers suggestive of H2SO4-dimethylamine (DMA)-water (H2O) nucleation, including sulfuric acid dimers and H2SO4-DMA clusters. In a cluster kinetics simulation, the obsd. concn. of sulfuric acid was high enough to explain the particle growth to ∼3 nm under the very high condensation sink, whereas the subsequent higher growth rate beyond this size is believed to result from the added contribution of condensing org. species. These findings will help in understanding urban NPF and its air quality and climate effects, as well as in formulating policies to mitigate secondary particle formation in China.
- 6Chu, B. W.; Kerminen, V. M.; Bianchi, F.; Yan, C.; Petäjä, T.; Kulmala, M. Atmospheric new particle formation in China. Atmos. Chem. Phys. 2019, 19 (1), 115– 138, DOI: 10.5194/acp-19-115-20196https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC1MXitFyjs7w%253D&md5=ca998646467f1b14af5f8fba2823e6c1Atmospheric new particle formation in ChinaChu, Biwu; Kerminen, Veli-Matti; Bianchi, Federico; Yan, Chao; Petaja, Tuukka; Kulmala, MarkkuAtmospheric Chemistry and Physics (2019), 19 (1), 115-138CODEN: ACPTCE; ISSN:1680-7324. (Copernicus Publications)New particle formation (NPF) studies in China were summarized comprehensively in this paper. NPF frequency, formation rate, and particle growth rate were closely compared among the observations carried out at different types of sites in different regions of China in different seasons, with the aim of exploring the nucleation and particle growth mechanisms. The interactions between air pollution and NPF are discussed, emphasizing the properties of NPF under heavy pollution conditions. The current understanding of NPF cannot fully explain the frequent occurrence of NPF at high aerosol loadings in China, and possible reasons for this phenomenon are proposed. The effects of NPF and some aspects of NPF research requiring further investigation are also summarized in this paper.
- 7Chen, H.; Wang, M.; Yao, L.; Chen, J.; Wang, L. Uptake of Gaseous Alkylamides by Suspended Sulfuric Acid Particles: Formation of Ammonium/Aminium Salts. Environ. Sci. Technol. 2017, 51 (20), 11710– 11717, DOI: 10.1021/acs.est.7b031757https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2sXhsV2rsrfM&md5=05572bbf5fb96cec3a8cf7b8b3ad0b69Uptake of Gaseous Alkylamides by Suspended Sulfuric Acid Particles: Formation of Ammonium/Aminium SaltsChen, Hangfei; Wang, Mingyi; Yao, Lei; Chen, Jianmin; Wang, LinEnvironmental Science & Technology (2017), 51 (20), 11710-11717CODEN: ESTHAG; ISSN:0013-936X. (American Chemical Society)Amides represent an important class of N-contg. compds. in the atm. that can in theory interact with atm. acidic particles and contribute to secondary aerosol formation. Here, uptake coeffs. (γ) of 6 alkylamides (C1-C3) by suspended sulfuric acid particles were measured using an aerosol flow tube coupled to a high resoln. time-of-flight chem. ionization mass spectrometer (HRToF-CIMS). At 293 K and <3% relative humidity (RH), the measured uptake coeffs. for 6 alkylamides were (4.8-23) × 10-2. A neg. dependence upon RH was obsd. for both N-methylformamide and N,N-dimethylformamide, likely due to decreased mass accommodation coeffs. (α) at lower acidities. A neg. temp. dependence was obsd. for N,N-dimethylformamide under <3% RH, also consistent with the mass accommodation-controlled uptake processes. Chem. anal. of reacted sulfuric acid particles indicates that alkylamides hydrolyzed in the presence of water mols. to form ammonium or aminium. Our results suggest that multiphase uptake of amides will contribute to growth of atm. acidic particles and alter their chem. compn.
- 8Kerminen, V. M.; Chen, X. M.; Vakkari, V.; Petäjä, T.; Kulmala, M.; Bianchi, F. Atmospheric new particle formation and growth: review of field observations. Environ. Res. Lett. 2018, 13 (10), 103003, DOI: 10.1088/1748-9326/aadf3c8https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC1MXmt1Witrk%253D&md5=da269476bbf9282c0f21419fd5e01b29Atmospheric new particle formation and growth: review of field observationsKerminen, Veli-Matti; Chen, Xuemeng; Vakkari, Ville; Petaja, Tuukka; Kulmala, Markku; Bianchi, FedericoEnvironmental Research Letters (2018), 13 (10), 103003/1-103003/38CODEN: ERLNAL; ISSN:1748-9326. (IOP Publishing Ltd.)A review. This review focuses on the obsd. characteristics of atm. new particle formation (NPF) in different environments of the global troposphere. After a short introduction, we will present a theor. background that discusses the methods used to analyze measurement data on atm. NPF and the assocd. terminol. We will update on our current understanding of regional NPF, i.e. NPF taking simultaneously place over large spatial scales, and complement that with a full review on reported NPF and growth rates during regional NPF events. We will shortly review atm. NPF taking place at sub-regional scales. Since the growth of newly-formed particles into larger sizes is of great current interest, we will briefly discuss our observation-based understanding on which gaseous compds. contribute to the growth of newly-formed particles, and what implications this will have on atm. cloud condensation nuclei formation. We will finish the review with a summary of our main findings and future outlook that outlines the remaining research questions and needs for addnl. measurements.
- 9Mauldin, R. L.; Berndt, T.; Sipilä, M.; Paasonen, P.; Petäjä, T.; Kim, S.; Kurtén, T.; Stratmann, F.; Kerminen, V. M.; Kulmala, M. A new atmospherically relevant oxidant of sulphur dioxide. Nature 2012, 488 (7410), 193– 196, DOI: 10.1038/nature112789https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC38XhtFKiurjO&md5=f135832d658d216a9741a5da2be64b25A new atmospherically relevant oxidant of sulphur dioxideMauldin, R. L., III; Berndt, T.; Sipilae, M.; Paasonen, P.; Petaejae, T.; Kim, S.; Kurten, T.; Stratmann, F.; Kerminen, V.-M.; Kulmala, M.Nature (London, United Kingdom) (2012), 488 (7410), 193-196CODEN: NATUAS; ISSN:0028-0836. (Nature Publishing Group)Atm. oxidn. is a key phenomenon which connects atm. chem. with globally challenging environmental issues, e.g., climate change, stratospheric O2 loss, soil and water acidification, and air quality health effects. O3 and OH- and NO3- radicals are generally considered the dominant oxidants which initiate trace gas removal, including pollutants, from the atm. Atm. observations from a boreal forest region in Finland, supported by lab. expts. and theor. considerations, which allowed the authors to identify another compd., probably a stabilized Criegee intermediate (carbonyl oxide with 2 free radical sites) or its deriv., which has a significant capacity to oxidize SO2 and potentially other trace gases, are discussed. This compd. probably enhances atm. reactivity, particularly with regard to H2SO4 prodn., and consequently, atm. aerosol formation. Results suggested this new atmospherically relevant oxidn. route is important relative to OH- oxidn., at least at moderate radical concns. Also, the oxidn. chem. of this compd. seemed tightly linked to the presence of biogenic alkenes.
- 10Welz, O.; Savee, J. D.; Osborn, D. L.; Vasu, S. S.; Percival, C. J.; Shallcross, D. E.; Taatjes, C. A. Direct Kinetic Measurements of Criegee Intermediate (CH2OO) Formed by Reaction of CH2I with O2. Science 2012, 335 (6065), 204– 207, DOI: 10.1126/science.121322910https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC38XksVShug%253D%253D&md5=33d2432f3b200b4253cc96afa0595422Direct Kinetic Measurements of Criegee Intermediate (CH2OO) Formed by Reaction of CH2I with O2Welz, Oliver; Savee, John D.; Osborn, David L.; Vasu, Subith S.; Percival, Carl J.; Shallcross, Dudley E.; Taatjes, Craig A.Science (Washington, DC, United States) (2012), 335 (6065), 204-207CODEN: SCIEAS; ISSN:0036-8075. (American Association for the Advancement of Science)Ozonolysis is a major tropospheric removal mechanism for unsatd. hydrocarbons which proceeds via Criegee intermediates (carbonyl oxides) which play a key role in tropospheric oxidn. models. Until recently, no gas-phase Criegee intermediate had been obsd., and indirect detns. of their reaction kinetics gave derived rate coeffs. spanning orders of magnitude. This paper reports the direct photoionization mass spectrometric detection of formaldehyde oxide (CH2OO), a product of the reaction of CH2I with O2. This reaction enabled direct lab. detns. of CH2OO kinetics. Upper limits were extd. for reaction rate coeffs. with NO and water. CH2OO reactions with SO2 and NO2 were unexpectedly rapid and implied a substantially greater role of carbonyl oxides in tropospheric SO42- and NO3- chem. models than previously assumed.
- 11He, G. Z.; He, H. DFT studies on the heterogeneous oxidation of SO2 by oxygen functional groups on graphene. Phys. Chem. Chem. Phys. 2016, 18 (46), 31691– 31697, DOI: 10.1039/C6CP06665H11https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC28XhslGgtbjO&md5=5f5c6a52cbb3abe1d771e0e956ffbd9cDFT studies on the heterogeneous oxidation of SO2 by oxygen functional groups on grapheneHe, Guangzhi; He, HongPhysical Chemistry Chemical Physics (2016), 18 (46), 31691-31697CODEN: PPCPFQ; ISSN:1463-9076. (Royal Society of Chemistry)The heterogeneous oxidn. of SO2 has been the subject of intense scrutiny in atm. chem. because of the adverse effects of sulfate particles. Although it has been found that the soot particles with a graphene-like structure play an important role in the oxidn. of SO2, little is known about the at.-level mechanism involved. Here, we studied the oxidn. of SO2 on oxygen-functionalized graphene using d. functional theory (DFT) calcn. The results showed that SO2 is oxidized by the epoxide group via a two-step mechanism, where the C-O bond away from the SO2 is broken first, followed by the breaking of the other C-O bond and the synchronous formation of a new S-O bond. The energy barriers are significantly decreased when solvation free energies are involved, suggesting that humidity is favorable for promoting the oxidn. by reducing the reaction barrier. The energy barriers for H2SO3 oxidn. are much higher than that for SO2 oxidn., indicating that the direct conversion of SO2 to SO3 is the main pathway for the oxidn. of SO2 by oxygen-functionalized graphene sheets in both the gas phase and soln. The reduced d. gradient (RDG) anal. showed that the hydrogen bond formed between H2SO3 and epoxide groups enhances the stability of the reaction complex, and is responsible for the high energy barrier that has to be overcome for the reaction to proceed. These atomistic studies proposed a two-step mechanism for the oxidn. of SO2 on the oxygen-functionalized graphene-like carbonaceous surfaces under ambient conditions.
- 12He, G. Z.; Ma, J. Z.; He, H. Role of Carbonaceous Aerosols in Catalyzing Sulfate Formation. ACS Catal. 2018, 8 (5), 3825– 3832, DOI: 10.1021/acscatal.7b0419512https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC1cXmtVWrtLc%253D&md5=459a3df2c042cb38c4b4ba5dbdc54e2dRole of Carbonaceous Aerosols in Catalyzing Sulfate FormationHe, Guangzhi; Ma, Jinzhu; He, HongACS Catalysis (2018), 8 (5), 3825-3832CODEN: ACCACS; ISSN:2155-5435. (American Chemical Society)The persistent and fast formation of sulfate is a primary factor driving the explosive growth of fine particles and exacerbating China's severe haze development. However, the underlying mechanism for the persistent prodn. of sulfate remains highly uncertain. Here, we demonstrate that soot is not only a major component of the particulate matter but also a natural carbocatalyst to activate mol. O2 and catalyze the oxidn. of SO2 to sulfate under ambient conditions. Moreover, high relative humidity, typically occurring in severe haze events, can greatly accelerate the catalytic cycle by reducing the reaction barriers, leading to faster sulfate prodn. The formation pathway of sulfate catalyzed by carbonaceous soot aerosols uses the ubiquitous O2 as the ultimate oxidant and can proceed at night when photochem. is reduced. The high relative humidity during haze episodes can further promote the soot-catalyzed sulfate-producing process. Therefore, this study reveals a missing and widespread source for the persistent sulfate haze formation in the open atm., particularly under highly polluted conditions characterized by high concns. of both SO2 and particulate carbon, and is helpful to the development of more efficient policies to mitigate and control haze pollution.
- 13Lizzio, A. A.; DeBarr, J. A. Mechanism of SO2 removal by carbon. Energy Fuels 1997, 11 (2), 284– 291, DOI: 10.1021/ef960197+13https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADyaK2sXit1ersbY%253D&md5=d66565b7c7e2ad7c54204e3817fb0086Mechanism of SO2 Removal by CarbonLizzio, Anthony A.; DeBarr, Joseph A.Energy & Fuels (1997), 11 (2), 284-291CODEN: ENFUEM; ISSN:0887-0624. (American Chemical Society)The reaction of SO2 with carbon in the presence of O2 and H2O involves a series of reactions that leads to the formation of sulfuric acid as the final product. The rate-detg. step in the overall process is the oxidn. of SO2 to SO3. Three SO2 oxidn. reactions are possible. Adsorbed SO2 (C-SO2) can react either with gas-phase O2 or with adsorbed oxygen (C-O complex) to form sulfur trioxide (SO3), or gas phase SO2 can react directly with the C-O complex. In optimizing the SO2 removal capabilities of carbon, most studies only assume a given mechanism for SO2 adsorption and conversion to H2SO4 to be operable. The appropriate SO2 oxidn. step and role of the C-O complex in this mechanism remain to be detd. The ultimate goal of this study was to prep. activated char from Illinois coal with optimal properties for low-temp. (80-150°) removal of sulfur dioxide from coal combustion flue gas. The SO2 adsorption capacity of activated char was found to be inversely proportional to the amt. of oxygen adsorbed on its surface. A temp.-programmed desorption technique was developed to titrate those sites responsible for adsorption of SO2 and conversion to H2SO4. On the basis of these results, a mechanism for SO2 removal by carbon was proposed. The derived rate expression showed SO2 adsorption to be dependent only on the fundamental rate const. and concn. of carbon atoms designated as free sites. Recent studies indicate a similar relationship exists between the rate of carbon gasification (in CO2 or H2O) and the no. of reactive sites as detd. by transient kinetics expts. Utilizing the concept of active or free sites, it was possible to produce a char from Illinois coal having an SO2 adsorption capacity surpassing that of the best available com. activated carbon.
- 14Han, C.; Liu, Y. C.; Ma, J. Z.; He, H. Key role of organic carbon in the sunlight-enhanced atmospheric aging of soot by O2. Proc. Natl. Acad. Sci. U. S. A. 2012, 109 (52), 21250– 21255, DOI: 10.1073/pnas.121269011014https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXoslShsQ%253D%253D&md5=9391213fb02bfb393b48c2c7708b9e41Key role of organic carbon in the sunlight-enhanced atmospheric aging of soot by O2Han, Chong; Liu, Yongchun; Ma, Jinzhu; He, HongProceedings of the National Academy of Sciences of the United States of America (2012), 109 (52), 21250-21255, S21250/1-S21250/6CODEN: PNASA6; ISSN:0027-8424. (National Academy of Sciences)Soot particles are ubiquitous in the atm. and have important climatic and health effects. The aging processes of soot during long-range transport result in variability in its morphol., microstructure, and hygroscopic and optical properties, subsequently leading to the modification of soot's climatic and health effects. In the present study the aging process of soot by mol. O2 under simulated sunlight irradn. is investigated. Org. carbon components on the surface of soot are found to play a key role in soot aging and are transformed into oxygen-contg. org. species including quinones, ketones, aldehydes, lactones, and anhydrides. These oxygen-contg. species may become adsorption centers of water and thus enhance the cloud condensation nuclei and ice nuclei activities of soot. Under irradn. of 25 mW·cm-2, the apparent rate consts. (k1,obs) for loss or formation of species on soot aged by 20% O2 were larger by factors of 1.5-3.5 than those on soot aged by 100 ppb O3. Considering the abundance of O2 in the troposphere and its higher photoreactivity rate, the photochem. oxidn. by O2 under sunlight irradn. should be a very important aging process for soot.
- 15He, G.; He, H. Water Promotes the Oxidation of SO2 by O2 over Carbonaceous Aerosols. Environ. Sci. Technol. 2020, 54 (12), 7070– 7077, DOI: 10.1021/acs.est.0c0002115https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB3cXotVehtLw%253D&md5=297fa7f3d5416f09f8bd1f5dbb54e01cWater Promotes the Oxidation of SO2 by O2 over Carbonaceous AerosolsHe, Guangzhi; He, HongEnvironmental Science & Technology (2020), 54 (12), 7070-7077CODEN: ESTHAG; ISSN:0013-936X. (American Chemical Society)Severe haze episodes typically occur with concurrent high relative humidity. The vital role of water in promoting SO2 oxidn. by O2 on carbonaceous soot surfaces was identified at the at. level by first-principles calcns. Water mols. dissoc. into surface hydroxyl groups through a self-catalyzed process at ambient conditions. Surface hydroxyl groups, acting as facilitators, significantly accelerated SO2 conversion to SO3 (particulate SO42- precursor) over soot aerosols by reducing reaction barriers. Specifically, hydroxyl groups activated reactants and stabilized transition states and products via H-bond interactions, making reactions thermodynamically and kinetically more favorable at room temp. Results indicated atm. humidity plays an important role in enhancing atm. oxidn. capacity, thereby exacerbating SO2 oxidn. and severe haze development. Results also unraveled a mechanism of surface hydroxyl-assisted O2 and water dissocn. over metal-free carbo-catalysts at ambient conditions.
- 16Novakov, T.; Chang, S. G.; Harker, A. B. Sulfates as Pollution Particulates - Catalytic Formation on Carbon (soot) Particles. Science 1974, 186 (4160), 259– 261, DOI: 10.1126/science.186.4160.25916https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADyaE2cXlsFyjtbY%253D&md5=5c495f23330508ce6f01f100fbd79949Sulfates as pollution particulates. Catalytic formation on carbon (soot) particlesNovakov, T.; Chang, S. G.; Harker, A. B.Science (Washington, DC, United States) (1974), 186 (4160), 259-61CODEN: SCIEAS; ISSN:0036-8075.Exptl. evidence (obtained by electron spectroscopy for chem. anal.) is presented which shows that finely divided C (soot) particles may play a major role in the catalytic oxidn. of SO2 to sulfate in polluted atms. The results obtained with sulfates produced in the lab. by the oxidn. of SO2 on graphite particles and combustion-produced soot particles are compared with the properties and behavior of ambient sulfates. The proposed SO2 oxidn. mechanism is qual. consistent with field observation.
- 17Zhao, Y.; Liu, Y. C.; Ma, J. Z.; Ma, Q. X.; He, H. Heterogeneous reaction of SO2 with soot: The roles of relative humidity and surface composition of soot in surface sulfate formation. Atmos. Environ. 2017, 152, 465– 476, DOI: 10.1016/j.atmosenv.2017.01.00517https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2sXosVWiuw%253D%253D&md5=d071aeed78f41efd34c590ceaef6cd55Heterogeneous reaction of SO2 with soot: The roles of relative humidity and surface composition of soot in surface sulfate formationZhao, Yan; Liu, Yongchun; Ma, Jinzhu; Ma, Qingxin; He, HongAtmospheric Environment (2017), 152 (), 465-476CODEN: AENVEQ; ISSN:1352-2310. (Elsevier Ltd.)The conversion of SO2 to sulfates on the surface of soot is still poorly understood. Soot samples with different fractions of unsatd. hydrocarbons and oxygen-contg. groups were prepd. by combusting n-hexane under well-controlled conditions. The heterogeneous reaction of SO2 with soot was investigated using in situ attenuated total internal reflection IR (ATR-IR) spectroscopy, ion chromatog. (IC) and a flow tube reactor at the ambient pressure and relative humidity (RH). Water promoted SO2 adsorption and sulfate formation at the RH range from 6% to 70%, while exceeded water condensed on soot was unfavorable for sulfate formation due to inhibition of SO2 adsorption when RH was higher than 80%. The surface compn. of soot, which was governed by combustion conditions, also played an important role in the heterogeneous reaction of SO2 with soot. This effect was found to greatly depend on RH. At low RH of 6%, soot with the highest fuel/oxygen ratio of 0.162 exhibited a max. uptake capacity for SO2 because it contained a large amt. of arom. C-H groups, which acted as active sites for SO2 adsorption. At RH of 54%, soot produced with a fuel/oxygen ratio of 0.134 showed the highest reactivity toward SO2 because it contained appropriate amts. of arom. C-H groups and oxygen-contg. groups, subsequently leading to the optimal surface concns. of both SO2 and water. These results suggest that variation in the surface compn. of soot from different sources and/or resulting from chem. aging in the atm. likely affects the conversion of SO2 to sulfates.
- 18He, X.; Pang, S. F.; Ma, J. B.; Zhang, Y. H. Influence of relative humidity on heterogeneous reactions of O3 and O3/SO2 with soot particles: Potential for environmental and health effects. Atmos. Environ. 2017, 165, 198– 206, DOI: 10.1016/j.atmosenv.2017.06.04918https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2sXhtFamt7vO&md5=97288dbd6b4337acebf019a3134e4e27Influence of relative humidity on heterogeneous reactions of O3 and O3/SO2 with soot particles: Potential for environmental and health effectsHe, Xiang; Pang, Shufeng; Ma, Jiabi; Zhang, YunhongAtmospheric Environment (2017), 165 (), 198-206CODEN: AENVEQ; ISSN:1352-2310. (Elsevier Ltd.)The heterogeneous reactions of soot particles with O3 and the mixt. of O3 and SO2 were studied as a function of relative humidities (RHs). The reactions were followed in real time using microscopic Fourier transform IR (micro-FTIR) spectrometer to obtain kinetic data. The results show that the ketone (C=O) group is the main product of the O3/soot reaction, and the sulfate is identified on the surface of soot particles in the presence of O3/SO2. Both reactions are sensitive to RHs and surrounding water significantly promotes the proceeding of the heterogeneous reactions. For the O3/soot reaction, the pseudo-first-order rate const. increases from 3.2 × 10-4 s-1 to 7.1 × 10-4 s-1 with increasing RH in the range of 1%-82%. When O3 and SO2 exist simultaneously during the reaction, the reaction rate and uptake coeff. are all enhanced by about an order of magnitude as the RH increases from 1% to 83%. The high productions of the ketone and sulfate on soot surface are of highly hydrophilic, which play a key role in environmental effect under humid environment. The possible reaction mechanism speculates that products of arom. carbonyls and dihydrofuran species on soot particles will be more harmful to human health.
- 19Zhang, F.; Wang, Y.; Peng, J.; Chen, L.; Sun, Y.; Duan, L.; Ge, X.; Li, Y.; Zhao, J.; Liu, C.; Zhang, X.; Zhang, G.; Pan, Y.; Wang, Y.; Zhang, A. L.; Ji, Y.; Wang, G.; Hu, M.; Molina, M. J.; Zhang, R. An unexpected catalyst dominates formation and radiative forcing of regional haze. Proc. Natl. Acad. Sci. U. S. A. 2020, 117 (8), 3960– 3966, DOI: 10.1073/pnas.191934311719https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB3cXjvFGksrc%253D&md5=331fd6695f9b154e575fb2d8b7c0f129An unexpected catalyst dominates formation and radiative forcing of regional hazeZhang, Fang; Wang, Yuan; Peng, Jianfei; Chen, Lu; Sun, Yele; Duan, Lian; Ge, Xinlei; Li, Yixin; Zhao, Jiayun; Liu, Chao; Zhang, Xiaochun; Zhang, Gen; Pan, Yuepeng; Wang, Yuesi; Zhang, Annie L.; Ji, Yuemeng; Wang, Gehui; Hu, Min; Molina, Mario J.; Zhang, RenyiProceedings of the National Academy of Sciences of the United States of America (2020), 117 (8), 3960-3966CODEN: PNASA6; ISSN:0027-8424. (National Academy of Sciences)Although regional haze adversely affects human health and possibly counteracts global warming from increasing levels of greenhouse gases, the formation and radiative forcing of regional haze on climate remain uncertain. By combining field measurements, lab. expts., and model simulations, we show a remarkable role of black carbon (BC) particles in driving the formation and trend of regional haze. Our anal. of long-term measurements in China indicates declined frequency of heavy haze events along with significantly reduced SO2, but negligibly alleviated haze severity. Also, no improving trend exists for moderate haze events. Our complementary lab. expts. demonstrate that SO2 oxidn. is efficiently catalyzed on BC particles in the presence of NO2 and NH3, even at low SO2 and intermediate relative humidity levels. Inclusion of the BC reaction accounts for ∼90-100% and 30-50% of the sulfate prodn. during moderate and heavy haze events, resp. Calcns. using a radiative transfer model and accounting for the sulfate formation on BC yield an invariant radiative forcing of nearly zero W m2 on the top of the atm. throughout haze development, indicating small net climatic cooling/warming but large surface cooling, atm. heating, and air stagnation. This BC catalytic chem. facilitates haze development and explains the obsd. trends of regional haze in China. Our results imply that redn. of SO2 alone is insufficient in mitigating haze occurrence and highlight the necessity of accurate representation of the BC chem. and radiative properties in predicting the formation and assessing the impacts of regional haze.
- 20Shen, J. L.; Zheng, C. H.; Xu, L. J.; Zhang, Y.; Zhang, Y. X.; Liu, S. J.; Gao, X. Atmospheric emission inventory of SO3 from coal-fired power plants in China in the period 2009–2014. Atmos. Environ. 2019, 197, 14– 21, DOI: 10.1016/j.atmosenv.2018.10.00820https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC1cXitVygs7jL&md5=afb682ca28aa880a2201ae72fcd488a8Atmospheric emission inventory of SO3 from coal-fired power plants in China in the period 2009-2014Shen, Jiali; Zheng, Chenghang; Xu, Linjie; Zhang, Yang; Zhang, Yongxin; Liu, Shaojun; Gao, XiangAtmospheric Environment (2019), 197 (), 14-21CODEN: AENVEQ; ISSN:1352-2310. (Elsevier Ltd.)Sulfur trioxide (SO3) pollution is becoming another severe problem in coal-fired power plants after SO2, NOx, and PM, however, the characteristics of SO3 emission in China remains unclear. In this paper, we established a refined activity data, and summarized the removal efficiency of different control technologies according to the literature review and field test results. An emission inventory of SO3 from coal-fired power plants in China between 2009 and 2014 was developed, which indicated the SO3 emission increased from 199.7 kilotons (kt) to 314.6 kt at an av. annual growth rate of 9.7%. The results show that Neimenggu, Sh‾anxi, Jiangsu, Shandong, Guangdong and Guizhou were the largest emitters, accounting for 49.7% of the total SO3 emissions in 2014. We analyzed the historical data with ArcGIS system, which allocates the emission into 36 km × 36 km grid cells. In addn., the result shows the unevenly spatial distribution. Combined with future economic development as well as implementation of policy, three different scenarios were set to project SO3 emission in coal-fired power plants in 2020, which represented the potential of SO3 emission redn. Compared with scenario A, SO3 emission can be reduced to 83.9 kt in scenario B, and in scenarios C, SO3 emission can be reduced to 38.4 kt. Coal-fired power plants should adopt different technol. routes to meet the ultra-low emission requirement and reduce the SO3 emission according to the boiler type, sulfur content, and the emission std.
- 21Yang, Z.; Ji, P.; Li, Q.; Jiang, Y.; Zheng, C.; Wang, Y.; Gao, X.; Lin, R. Comprehensive understanding of SO3 effects on synergies among air pollution control devices in ultra-low emission power plants burning high-sulfur coal. J. Cleaner Prod. 2019, 239, 118096, DOI: 10.1016/j.jclepro.2019.11809621https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC1MXhs1CntbnN&md5=fa4c384c4dff27f71a90c4dba88f87e3Comprehensive understanding of SO3 effects on synergies among air pollution control devices in ultra-low emission power plants burning high-sulfur coalYang, Zhengda; Ji, Peidong; Li, Qingyi; Jiang, Ye; Zheng, Chenghang; Wang, Yi; Gao, Xiang; Lin, RiyiJournal of Cleaner Production (2019), 239 (), 118096CODEN: JCROE8; ISSN:0959-6526. (Elsevier Ltd.)The environmental issue of SO3 pollution caused by coal-fired power plants attracts increasing attention. This work focused on the synergies between air pollution control devices in a 660 MW power plant burning high-sulfur coal. Parameters such as gas temp. and flow rate were varied within wide ranges under actual conditions. Both continuously tested SO3 concn. and online operational data were combined to establish a correlation between device performance and operational parameter. Results indicated that the gas temp. acted as a bridge of synergies between the electrostatic precipitator (ESP) and wet electrostatic precipitator (WESP). The SO3 removal efficiency across the ESP increased from 60.3% to 91.1% with the gas temp. decreasing from 136.7 to 114.8°C, leading to the increase in corona current and the decrease in spark-over frequency of WESP. Moreover, addnl. elec. field stages are also effective to enhance the corona current and reduce spark-over frequency. Furthermore, deviations between the design and operational data within 0-100% loading provided a correction to appropriately choose the gas velocity. With the proposed countermeasures, the SO3 emission can achieve a favorable level less than 5 mg/m3. The research findings provide a valuable tech. pathway to eliminate the SO3 emission from power plants burning high-sulfur coal.
- 22Roy, B.; Chen, L. G.; Bhattacharya, S. Nitrogen Oxides, Sulfur Trioxide, and Mercury Emissions during Oxyfuel Fluidized Bed Combustion of Victorian Brown Coal. Environ. Sci. Technol. 2014, 48 (24), 14844– 14850, DOI: 10.1021/es504667r22https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXhvFGktbjE&md5=8a172a28941748f050c794ddd1c017dcNitrogen Oxides, Sulfur Trioxide, and Mercury Emissions during Oxy-fuel Fluidized Bed Combustion of Victorian Brown CoalRoy, Bithi; Chen, Luguang; Bhattacharya, SankarEnvironmental Science & Technology (2014), 48 (24), 14844-14850CODEN: ESTHAG; ISSN:0013-936X. (American Chemical Society)This study investigates, for the first time, the NOx, N2O, SO3, and Hg emissions from combustion of a Victorian brown coal in a 10 kWth fluidized bed unit under oxy-fuel combustion conditions. Compared to air combustion, lower NOx emissions and higher N2O formation were obsd. in the oxy-fuel atm. These NOx redn. and N2O formations were further enhanced with steam in the combustion environment. The NOx concn. level in the flue gas was within the permissible limit in coal-fired power plants in Victoria. Therefore, an addnl. NOx removal system will not be required using this coal. In contrast, both SO3 and gaseous mercury concns. were considerably higher under oxy-fuel combustion compared to that in the air combustion. Around 83% of total gaseous mercury released was Hg0, with the rest emitted as Hg2+. Therefore, to control harmful Hg0, a mercury removal system may need to be considered to avoid corrosion in the boiler and CO2 sepn. units during the oxy-fuel fluidized-bed combustion using this coal.
- 23Morokuma, K.; Muguruma, C. Ab-Initio Molecular-Orbital Study of the Mechanism of the Gas-Phase Reaction SO3+H2O - Importance of the 2nd Water Molecule. J. Am. Chem. Soc. 1994, 116 (22), 10316– 10317, DOI: 10.1021/ja00101a06823https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADyaK2cXms1Ckt7Y%253D&md5=3009e4c4460d0b49f24c631bc34c5294Ab initio Molecular Orbital Study of the Mechanism of the Gas Phase Reaction SO3 + H2O: Importance of the Second Water MoleculeMorokuma, Keiji; Muguruma, ChizuruJournal of the American Chemical Society (1994), 116 (22), 10316-17CODEN: JACSAT; ISSN:0002-7863.An ab initio MO method was used to calc. the structures and energetics of complexes and transition states for the reaction of nH2O + SO3 → (n-1)H2SO4 for n = 0 and 1. While the barrier for the 1:1 reaction is very high, two water mols. can react with SO3 very easily to convert it to sulfuric acid. The transition state for this easy reaction is six-centered, with transfer of two protons taking place simultaneously.
- 24Kolb, C. E.; Jayne, J. T.; Worsnop, D. R.; Molina, M. J.; Meads, R. F.; Viggiano, A. A. Gas-Phase Reaction of Sulfur-Trioxide with Water-Vapor. J. Am. Chem. Soc. 1994, 116 (22), 10314– 10315, DOI: 10.1021/ja00101a06724https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADyaK2cXms1Ckt7c%253D&md5=da41b22cb0e8382cf2356b40268d788aGas Phase Reaction of Sulfur Trioxide with Water VaporKolb, C. E.; Jayne, J. T.; Worsnop, D. R.; Molina, M. J.; Meads, R. F.; Viggiano, A. A.Journal of the American Chemical Society (1994), 116 (22), 10314-15CODEN: JACSAT; ISSN:0002-7863.Castleman and co-workers have interpreted the gas phase SO3/H2O reaction in terms of adduct formation followed by unimol. rearrangement to H2SO4: SO3 + H2O + (M) → SO3·H2O + (M) (1); SO3·H2O → H2SO4 (2). However, recent theor. calcns. by Popov et al., Hoffmann and Schleyer, and Morokuma and Muguruma have cast serious doubt on this interpretation. These studies find that the computed activation barrier for reaction 2 is significantly larger than the calcd. binding energy for the SO3·H2O adduct, indicating that any adduct with sufficient internal energy to rearrange will more likely simply dissoc. back to reactants. Exptl. kinetics results reported here also cast serious doubt on the mechanism represented by reactions 1 and 2. We have investigated the gas phase SO3 + H2O reaction in an atm. pressure turbulent flow reactor designed to minimize the influence of wall reactions. We have also studied the reaction of SO3 and H2O vapor as a function of temp. over the range of -30 to +60°, observing a significant (>10×) increase in reaction rate as the temp. is lowered over this range. This observation, combined with the data shown and the calcns. of Morokuma and Muguruma, leads us to propose that a significant portion of the obsd. SO3 consumption likely involves reaction with the water dimer: SO3 + (H2O)2 → H2SO4 + H2O which Morokuma and Muguruma calc. proceeds through a six center transition state with a very small activation energy. The obsd. neg. temp. dependence is presumably due to the higher abundance of water dimer at lower temps. as well as a more favorable competition between reaction 3 and the alternative path to form an SO3.H2O adduct: SO3 + (H2O)2 → SO3.H2O + H2O (4). Reaction 4 is calcd. to be approx. 3.5 kcal/mol exothermic. It is reasonable to assume that the fraction of reaction between SO3 and (H2O)2 proceeding through the six-center transition state computed for reaction 3 will also increase with decreasing temp. At this time it is unclear whether H2SO4 is also formed directly through the reaction of the SO3.H2O adduct with water vapor: SO3.H2O + H2O → H2SO4 + H2O.
- 25Li, H.; Zhong, J.; Vehkamaki, H.; Kurten, T.; Wang, W. G.; Ge, M. F.; Zhang, S. W.; Li, Z. S.; Zhang, X. H.; Francisco, J. S.; Zeng, X. C. Self-Catalytic Reaction of SO3 and NH3 To Produce Sulfamic Acid and Its Implication to Atmospheric Particle Formation. J. Am. Chem. Soc. 2018, 140 (35), 11020– 11028, DOI: 10.1021/jacs.8b0492825https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC1cXhsVOjsL%252FN&md5=2ce70a20fa5287e046fb317d9b4953e0Self-Catalytic Reaction of SO3 and NH3 To Produce Sulfamic Acid and Its Implication to Atmospheric Particle FormationLi, Hao; Zhong, Jie; Vehkamaki, Hanna; Kurten, Theo; Wang, Weigang; Ge, Maofa; Zhang, Shaowen; Li, Zesheng; Zhang, Xiuhui; Francisco, Joseph S.; Zeng, Xiao ChengJournal of the American Chemical Society (2018), 140 (35), 11020-11028CODEN: JACSAT; ISSN:0002-7863. (American Chemical Society)Sulfur trioxide (SO3) is one of the most active chem. species in the atm., and its atm. fate has profound implications to air quality and human health. The dominant gas-phase loss pathway for SO3 is generally believed to be the reaction with water mols., resulting in sulfuric acid. The latter is viewed as a crit. component in the new particle formation (NPF). Herein, a new and competitive loss pathway for SO3 in the presence of abundant gas-phase ammonia (NH3) species is identified. Specifically, the reaction between SO3 and NH3, which produces sulfamic acid, can be self-catalyzed by the reactant (NH3). In dry and heavily polluted areas with relatively high concns. of NH3, the effective rate const. for the bimol. SO3-NH3 reaction can be sufficiently fast through this new loss pathway for SO3 to become competitive with the conventional loss pathway for SO3 with water. Furthermore, this study shows that the final product of the reaction, namely, sulfamic acid, can enhance the fastest possible rate of NPF from sulfuric acid and dimethylamine (DMA) by about a factor of 2. An alternative source of stabilizer for acid-base clustering in the atm. is suggested, and this new mechanism for NPF has potential to improve atm. modeling in highly polluted regions.
- 26Sarkar, S.; Oram, B. K.; Bandyopadhyay, B. Influence of Ammonia and Water on the Fate of Sulfur Trioxide in the Troposphere: Theoretical Investigation of Sulfamic Acid and Sulfuric Acid Formation Pathways. J. Phys. Chem. A 2019, 123 (14), 3131– 3141, DOI: 10.1021/acs.jpca.8b0930626https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC1MXlvVSlur4%253D&md5=1e408f19798d1330180a0acd1d4a6fb4Influence of Ammonia and Water on the Fate of Sulfur Trioxide in the Troposphere: Theoretical Investigation of Sulfamic Acid and Sulfuric Acid Formation PathwaysSarkar, Saptarshi; Oram, Binod Kumar; Bandyopadhyay, BimanJournal of Physical Chemistry A (2019), 123 (14), 3131-3141CODEN: JPCAFH; ISSN:1089-5639. (American Chemical Society)The reaction of NH3 with SO3 as a potential sulfamic acid source in the troposphere was examd. by electronic structure and chem. kinetic calcns. The hydrolysis reaction, a known major atm. SO3 decay channel, was also assessed. The catalytic effect of NH3 and water on both the reactions was studied. Rate coeffs. for all studied reaction mechanisms were calcd. using transition state theory with pre-equil. approxn. Calcd. rate coeffs. for several catalyzed hydrolysis and ammonolysis processes were much higher (∼105 to ∼109 times) than the gas kinetic limit at ambient temp. With a temp. decrease due to neg. temp. dependence of rate coeffs., that difference became even larger (up to ∼1016 times). Hence, to remove discrepancies, rate coeffs. for all studied reaction mechanisms were calcd. using master chem. equations. Results showed marked improvements; only one mechanism exhibited a slightly higher rate coeff. above the gas kinetic limit. Rate coeffs. for catalyzed reaction mechanisms obtained from the master equation also showed neg. temp. dependence, albeit to a much smaller extent. The uncatalyzed ammonolysis reaction, similar to the corresponding hydrolysis, was too slow to have any practical atm. implications. For both reactions, NH3-catalyzed mechanisms had higher rate coeffs. than water-catalyzed mechanisms. Between hydrolysis and ammonolysis, the latter showed a higher rate coeff. Despite that, ammonolysis is expected to have negligible contribution for tropospheric SO3 loss due to the large difference in concns. between water and NH3 in the troposphere.
- 27Lv, G. C.; Sun, X. M.; Zhang, C. X.; Li, M. Understanding the catalytic role of oxalic acid in SO3 hydration to form H2SO4 in the atmosphere. Atmos. Chem. Phys. 2019, 19 (5), 2833– 2844, DOI: 10.5194/acp-19-2833-201927https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC1MXosVahur4%253D&md5=44add63e2ab82d65cb6d2837a2b3d449Understanding the catalytic role of oxalic acid in SO3 hydration to form H2SO4 in the atmosphereLv, Guochun; Sun, Xiaomin; Zhang, Chenxi; Li, MeiAtmospheric Chemistry and Physics (2019), 19 (5), 2833-2844CODEN: ACPTCE; ISSN:1680-7324. (Copernicus Publications)The hydration of SO3 plays an important role in atm. sulfuric acid formation. Some atm. species can be involved in and facilitate the reaction. In this work, using quantum chem. calcns., we show that oxalic acid, the most common dicarboxylic acid in the atm., can effectively catalyze the hydration of SO3. The energy barrier of the SO3 hydration reaction catalyzed by oxalic acid (cTt, tTt, tCt and cCt conformers) is a little higher or less than 1 kcal mol-1, which is lower than the energy barrier of 5.17 kcal mol-1 for water-catalyzed SO3 hydration. Compared with the rates of the SO3 hydration reaction catalyzed by oxalic acid and water, it can be found that in the upper troposphere the OA-catalyzed SO3 hydration can play an important role in promoting SO3 hydration. It leads us to conclude that the involvement of oxalic acid in SO3 hydration to form H2SO4 is significant in the atm.
- 28Bandyopadhyay, B.; Kumar, P.; Biswas, P. Ammonia Catalyzed Formation of Sulfuric Acid in Troposphere: The Curious Case of a Base Promoting Acid Rain. J. Phys. Chem. A 2017, 121 (16), 3101– 3108, DOI: 10.1021/acs.jpca.7b0117228https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2sXlsVemsrk%253D&md5=3327e885e2a231e07cc7536ea86308d3Ammonia Catalyzed Formation of Sulfuric Acid in Troposphere: The Curious Case of a Base Promoting Acid RainBandyopadhyay, Biman; Kumar, Pradeep; Biswas, ParthaJournal of Physical Chemistry A (2017), 121 (16), 3101-3108CODEN: JPCAFH; ISSN:1089-5639. (American Chemical Society)Electronic structure calcns. were performed to assess the role of NH3 in catalyzing H2SO4 formation through SO3 hydrolysis in Earth atm. The uncatalyzed process involves a high activation barrier and, until now, is mainly known to occur in Earth atm. only when catalyzed by water and acids. This work showed that SO3 hydrolysis can be very efficiently catalyzed by NH3, the most abundant basic component in Earth atm. Based on the magnitude of relative potential energies and rate coeffs., NH3 was detd. best among all studied catalysts until now (water and acids) and could be a considerable factor for tropospheric H2SO4 formation. The calcd. rate coeff. (at 298° K) of the NH3-catalyzed reaction was ∼105-107 times greater than that for water catalyzed reaction. Based on relative rates of NH3 and water catalyzed processes, tropospheric NH3, in conjunction with water, could be the key factor detg. the H2SO4 formation rate. NH3 could surpass water in catalyzing H2SO4 formation via SO3 hydrolysis at various tropospheric altitudes depending on relative concns.
- 29Long, B.; Chang, C. R.; Long, Z. W.; Wang, Y. B.; Tan, X. F.; Zhang, W. J. Nitric acid catalyzed hydrolysis of SO3 in the formation of sulfuric acid: A theoretical study. Chem. Phys. Lett. 2013, 581, 26– 29, DOI: 10.1016/j.cplett.2013.07.01229https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXhtFynt7jN&md5=80ed449b68b064f74ffe8d948122356aNitric acid catalyzed hydrolysis of SO3 in the formation of sulfuric acid: A theoretical studyLong, Bo; Chang, Chun-Ran; Long, Zheng-Wen; Wang, Yi-Bo; Tan, Xing-Feng; Zhang, Wei-JunChemical Physics Letters (2013), 581 (), 26-29CODEN: CHPLBC; ISSN:0009-2614. (Elsevier B.V.)The gas-phase hydrolysis of SO3 in the presence of one water mol., two water mols., and nitric acid is studied using high level quantum chem. methods and transition state theory. The calcd. results demonstrate that nitric acid exerts a strong catalytic role in the hydrolysis of SO3 because the activated barrier of hydrolysis of SO3 with the assistance of nitric acid is reduced to ∼3.7 kcal/mol, which is ∼20 kcal/mol lower than that of the SO3 reaction with water relative to the resp. pre-reactive complex.
- 30Fleig, D.; Vainio, E.; Andersson, K.; Brink, A.; Johnsson, F.; Hupa, M. Evaluation of SO3Measurement Techniques in Air and Oxy-Fuel Combustion. Energy Fuels 2012, 26 (9), 5537– 5549, DOI: 10.1021/ef301127x30https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC38Xht1KjsrjM&md5=5554922b0714c5545df97860a0fddc8bEvaluation of SO3 Measurement Techniques in Air and Oxy-Fuel CombustionFleig, Daniel; Vainio, Emil; Andersson, Klas; Brink, Anders; Johnsson, Filip; Hupa, MikkoEnergy & Fuels (2012), 26 (9), 5537-5549CODEN: ENFUEM; ISSN:0887-0624. (American Chemical Society)SO2 is enriched in oxy-fuel combustion due to flue-gas recycle, and a significant higher SO3 concn. can be expected compared to air-firing. Since SO3 can cause high and low temp. corrosion, it is important to measure the SO3 concn. under oxy-fuel fired conditions. However, measurement of SO3 is not straightforward, since SO3 is a highly reactive gas. This paper presents an exptl. study in the Chalmers oxy-fuel test unit, comparing different SO3 measurement techniques applied during oxy-fuel and air combustion. Propane (60 kWth) was used as fuel and SO2 was injected in the oxidizer to generate a controllable amt. of SO3. The SO3 concn. was measured with four techniques: the controlled condensation method, the salt method, the isopropanol absorption bottle method, and with the Pentol SO3 monitor (previously: Severn Science analyzer). The controlled condensation method was used as the std. for comparison. Addnl., the acid dew-point temp. was measured with a dew-point meter. The controlled condensation and the salt method gave comparable results, and the repeatability with these methods was good. The SO3 concns. measured with the Pentol SO3 monitor differed in av. less than 20% from the SO3 concns. obtained with the controlled condensation method. With the isopropanol absorption bottle method, a large amt. of the SO2 was absorbed in the isopropanol soln., which gives a pos. bias if the SO2 is oxidized to sulfate in the isopropanol soln. This was minimized by reducing the measurement time, bubbling argon through the absorption bottles after the measurement to force the SO2 out, and analyzing the soln. immediately after the measurement. No principal differences between measuring the SO3 concn. during oxy-fuel combustion and air-firing were obtained. However, a correction factor for the mass flow meter of the Pentol SO3 monitor has to be used because of the high CO2 concn. during oxy-fuel operation.
- 31Lovejoy, E. R.; Hanson, D. R.; Huey, L. G. Kinetics and products of the gas-phase reaction of SO3 with water. J. Phys. Chem. 1996, 100 (51), 19911– 19916, DOI: 10.1021/jp962414d31https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADyaK28XntFSgt7w%253D&md5=97e38a420104d879949e9d20edfd087eKinetics and products of the gas-phase reaction of SO3 with waterLovejoy, E. R.; Hanson, D. R.; Huey, L. G.Journal of Physical Chemistry (1996), 100 (51), 19911-19916CODEN: JPCHAX; ISSN:0022-3654. (American Chemical Society)The kinetics of the gas-phase reactions of SO3 with H2O and D2O were studied over the temp. range 250-360 K in N2 with a laminar flow reactor coupled to a chem. ionization mass spectrometer. The SO3 loss is second order in the water concn., is independent of pressure (20-80 Torr N2, 300 K), and has a strong neg. temp. dependence and a significant H/D isotope effect (kH2O ≈ 2kD2O). The yield of sulfuric acid is 1.0 ± 0.5 per SO3 consumed. These observations are consistent with the rapid assocn. of SO3 and H2O to form the adduct H2OSO3 which reacts with water to produce sulfuric acid. The first-order rate coeffs. for loss of SO3 by reaction with H2O and D2O are given by kI(s-1) = (2.26 ± 0.85) × 10-43T exp((6544 ± 106)/T)[H2O]2 and (9.45 ± 2.68) × 10-44T exp((6573 ± 82)/T)[D2O]2, where T ≡ K and [H2O, D2O] ≡ mol. cm-3. The errors are the uncertainty at the 95% confidence level for precision only. Anal. of the temp. dependence of the SO3 loss yields an upper limit for the H2O-SO3 bond enthalpy of 13 kcal mol-1.
- 32Arnold, S. T.; Morris, R. A.; Viggiano, A. A.; Jayne, J. T. Ion Chemistry Relevant for Chemical-Ionization Detection of SO3. J. Geophys. Res. 1995, 100 (D7), 14141– 14146, DOI: 10.1029/95JD01004There is no corresponding record for this reference.
- 33Jayne, J. T.; Poschl, U.; Chen, Y. M.; Dai, D.; Molina, L. T.; Worsnop, D. R.; Kolb, C. E.; Molina, M. J. Pressure and temperature dependence of the gas-phase reaction of SO3 with H2O and the heterogeneous reaction of SO3 with H2O/H2SO4 surfaces. J. Phys. Chem. A 1997, 101 (51), 10000– 10011, DOI: 10.1021/jp972549z33https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADyaK2sXnvVCntrc%253D&md5=2e4f06ccb347cfff4e4d162b8405d473Pressure and temperature dependence of the gas-phase reaction of SO3 with H2O and the heterogeneous reaction of SO3 with H2O/H2SO4 surfacesJayne, John T.; Poeschl, Ulrich; Chen, Yu-min; Dai, David; Molina, Luisa T.; Worsnop, Douglas R.; Kolb, Charles E.; Molina, Mario J.Journal of Physical Chemistry A (1997), 101 (51), 10000-10011CODEN: JPCAFH; ISSN:1089-5639. (American Chemical Society)The gas-phase reaction of SO3 with H2O and the heterogeneous reaction of SO3 with H2O-H2SO4 surfaces have been studied in a fast flow reactor coupled to a chem. ionization mass spectrometer (CIMS) for species detection. The gas-phase reaction was studied under turbulent flow conditions over the pressure range from 100 to 760 Torr N2 and the temp. range from 283 to 370 K. The loss rate of SO3 was measured under pseudo-first-order conditions; it exhibits a second-order dependence on water vapor concn. and has a strong neg. temp. dependence. The first-order rate coeff. for the SO3 loss by gas-phase reaction shows no significant pressure dependence and can be expressed as kI(s-1) = 3.90 × 10-41 exp(6830.6/T)[H2O]2 where [H2O] is in units of mol. cm-3 and T is in Kelvin. The overall uncertainty of our exptl. detd. rate coeffs. is estd. to be ±20%. At sufficiently low SO3 concns. (<1012 mol. cm-3) the rate coeff. is independent of the initial SO3 level, as expected for a gas-phase reaction mechanism involving one SO3 and two H2O mols. However, at higher concns. and lower temps., increased rate coeffs. were obsd., indicating a fast heterogeneous reaction after the onset of binary homogeneous nucleation of acid hydrate clusters leading to particle formation, which was verified by light-scattering expts. The heterogeneous loss of SO3 to the reactor walls has also been investigated under low pressure (1.1-12.5 Torr) laminar flow conditions. The loss rate is highly dependent on the humidity of the surface. In the presence of excess water the reactive sticking coeff. approaches unity and the wall loss rate is gas diffusion limited; under dry conditions it approaches zero, as expected. The atm. implications of the homogeneous and heterogeneous SO3-water reaction are discussed.
- 34Sorokin, A.; Katragkou, E.; Arnold, F.; Busen, R.; Schumann, U. Gaseous SO3 and H2SO4 in the exhaust of an aircraft gas turbine engine: measurements by CIMS and implications for fuel sulfur conversion to sulfur (VI) and conversion of SO3 to H2SO4. Atmos. Environ. 2004, 38 (3), 449– 456, DOI: 10.1016/j.atmosenv.2003.09.06934https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD3sXptlChsLY%253D&md5=44c27e80a2f1377f489239e91f7a3427Gaseous SO3 and H2SO4 in the exhaust of an aircraft gas turbine engine: measurements by CIMS and implications for fuel sulfur conversion to sulfur (VI) and conversion of SO3 to H2SO4Sorokin, A.; Katragkou, E.; Arnold, F.; Busen, R.; Schumann, U.Atmospheric Environment (2004), 38 (3), 449-456CODEN: AENVEQ; ISSN:1352-2310. (Elsevier Science B.V.)An estn. of the conversion efficiency (.vepsiln.) of fuel sulfur to SO3 and H2SO4, where .vepsiln.=([SO3]+[H2SO4])/[ST] and [ST] is the total sulfur atom concn. in the exhaust at the exit of an aircraft gas-turbine combustor, was derived from measurements by comparison with model results. The major results of the presented CIMS expts. and their interpretation with a model simulation are: (i) The efficiency is .vepsiln.=2.3±1% at an exhaust age of about 5 ms from the combustor exit; (ii) The SO3 mols. represent a major fraction of sulfur (VI) gases .vepsiln.A<50% and an essential SO3-conversion to H2SO4 takes place in the sampling line where the exhaust gases spend a sufficiently long time and where the temp. is lower than in the hot exhaust. The coincidence of .vepsiln. from our work (measurements with the sampling point in the exhaust just behind the combustor exit) and .vepsiln. the measurements in an exhaust at a plume age of about 1 s suggests that the sulfur (VI) formation is inefficient in the post-combustor flow inside the aircraft engine.
- 35Berndt, T.; Scholz, W.; Mentler, B.; Fischer, L.; Hoffmann, E. H.; Tilgner, A.; Hyttinen, N.; Prisle, N. L.; Hansel, A.; Herrmann, H. Fast Peroxy Radical Isomerization and OH Recycling in the Reaction of OH Radicals with Dimethyl Sulfide. J. Phys. Chem. Lett. 2019, 10 (21), 6478– 6483, DOI: 10.1021/acs.jpclett.9b0256735https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC1MXhvFWltrjP&md5=0d91ffa9cadc1365ffbfb0a48fe0373bFast Peroxy Radical Isomerization and OH Recycling in the Reaction of OH Radicals with Dimethyl SulfideBerndt, T.; Scholz, W.; Mentler, B.; Fischer, L.; Hoffmann, E. H.; Tilgner, A.; Hyttinen, N.; Prisle, N. L.; Hansel, A.; Herrmann, H.Journal of Physical Chemistry Letters (2019), 10 (21), 6478-6483CODEN: JPCLCD; ISSN:1948-7185. (American Chemical Society)Di-Me sulfide (DMS), produced by marine organisms, represents the most abundant, biogenic sulfur emission into the Earth's atm. The gas-phase degrdn. of DMS is mainly initiated by the reaction with the OH radical forming first CH3SCH2O2 radicals from the dominant H-abstraction channel. It is exptl. shown that these peroxy radicals undergo a two-step isomerization process finally forming a product consistent with the formula HOOCH2SCHO. The isomerization process is accompanied by OH recycling. The rate-limiting first isomerization step, CH3SCH2O2 → CH2SCH2OOH, followed by O2 addn., proceeds with k = (0.23 ± 0.12) s-1 at 295 ± 2 K. Competing bimol. CH3SCH2O2 reactions with NO, HO2, or RO2 radicals are less important for trace-gas conditions over the oceans. Results of atm. chem. simulations demonstrate the predominance (≥95%) of CH3SCH2O2 isomerization. The rapid peroxy radical isomerization, not yet considered in models, substantially changes the understanding of DMS's degrdn. processes in the atm.
- 36Jokinen, T.; Sipilä, M.; Junninen, H.; Ehn, M.; Lönn, G.; Hakala, J.; Petäjä, T.; Mauldin, R. L.; Kulmala, M.; Worsnop, D. R. Atmospheric sulphuric acid and neutral cluster measurements using CI-APi-TOF. Atmos. Chem. Phys. 2012, 12 (9), 4117– 4125, DOI: 10.5194/acp-12-4117-201236https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC38XhtFOns7vM&md5=33186776d4f9cc0c19aa9298e0874ed0Atmospheric sulphuric acid and neutral cluster measurements using CI-APi-TOFJokinen, T.; Sipila, M.; Junninen, H.; Ehn, M.; Lonn, G.; Hakala, J.; Petaja, T.; Mauldin, R. L., III; Kulmala, M.; Worsnop, D. R.Atmospheric Chemistry and Physics (2012), 12 (9), 4117-4125CODEN: ACPTCE; ISSN:1680-7316. (Copernicus Publications)The first ambient measurements using nitrate ion based Chem. Ionization with the Atm. Pressure interface Time-Of-Flight mass spectrometer (CI-APi-TOF) for sulfuric acid and neutral cluster detection are presented. We have found CI-APi-TOF a highly stable and sensitive tool for mol. sulfuric acid detection. The lowest limit of detection for sulfuric acid was detd. to be 3.6 × 104 mols. cm-3 for 15 min averaging. Signals from sulfuric acid clusters up to tetramer contg. ammonia were also obtained but these were found to result from naturally charged clusters formed by ion induced clustering in the atm. during nucleation. Opposite to earlier studies with cluster mass spectrometers, we had no indication of neutral clusters. The reason is either less efficient charging of clusters in comparison to mol. sulfuric acid, or the low concn. of neutral clusters at our measurement site during these particular nucleation events. We show that utilizing high resoln. mass spectrometry is crucial in sepg. the weak sulfuric acid cluster signal from other compds.
- 37Kürten, A.; Rondo, L.; Ehrhart, S.; Curtius, J. Calibration of a chemical ionization mass spectrometer for the measurement of gaseous sulfuric acid. J. Phys. Chem. A 2012, 116 (24), 6375– 86, DOI: 10.1021/jp212123n37https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC38XivVOhsLc%253D&md5=983dc0a569a9a926132b2e25e7aeeab1Calibration of a Chemical Ionization Mass Spectrometer for the Measurement of Gaseous Sulfuric AcidKuerten, Andreas; Rondo, Linda; Ehrhart, Sebastian; Curtius, JoachimJournal of Physical Chemistry A (2012), 116 (24), 6375-6386CODEN: JPCAFH; ISSN:1089-5639. (American Chemical Society)Accurate measurement of gaseous H2SO4 concn. is crucial within many fields of atm. science. Instruments using chem. ionization mass spectrometry (CIMS) to measure H2SO4 require careful calibration. This work established a calibration source to provide stable, adjustable H2SO4 concns. This calibration system initiates H2SO4 prodn. by oxidizing SO2 by OH-. OH- is produced by UV photolysis of water vapor. A numerical model calcs. the H2SO4 concn. at the calibration source outlet. From comparison of this concn. and CIMS-measured signals, a calibration factor is derived. This factor was evaluated to be 1.1 × 1010/cm3, in good agreement with literature values for other H2SO4-measuring CIMS instruments. The described calibration system and results are discussed. Since the set-up is external to the CIMS instrument, it offers the possibility for future CIMS inter-comparison measurements by providing defined, stable H2SO4 concns.
- 38Mohler, O.; Reiner, T.; Arnold, F. The Formation of SO5– by Gas-Phase Ion–Molecule Reactions. J. Chem. Phys. 1992, 97 (11), 8233– 8239, DOI: 10.1063/1.463394There is no corresponding record for this reference.
- 39Anglada, J. M.; Hoffman, G. J.; Slipchenko, L. V.; Costa, M. M.; Ruiz-Lopez, M. F.; Francisco, J. S. Atmospheric Significance of Water Clusters and Ozone-Water Complexes. J. Phys. Chem. A 2013, 117 (40), 10381– 10396, DOI: 10.1021/jp407282c39https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXhsVehs7bK&md5=ee23b2ef1fea6c22aed226dc11742083Atmospheric Significance of Water Clusters and Ozone-Water ComplexesAnglada, Josep M.; Hoffman, Gerald J.; Slipchenko, Lyudmila V.; M. Costa, Marilia; Ruiz-Lopez, Manuel F.; Francisco, Joseph S.Journal of Physical Chemistry A (2013), 117 (40), 10381-10396CODEN: JPCAFH; ISSN:1089-5639. (American Chemical Society)Ozone-water complexes O3···(H2O)n (n = 1-4) have been theor. investigated using QCISD and CCSD-(T) methods along with the 6-311G-(2df,2p), 6-311+G-(2df,2p), aug-cc-pVDZ, aug-cc-pVTZ, and aug-cc-pVQZ basis sets and extrapolation to CBS limit. For comparison, water clusters (H2O)n (n = 1-4) have also been studied at the same level of theory. The ozone-water complexes are held together by a combination of weak specific hydrogen-bonding and van der Waals interactions. Surprisingly, the hydrogen-bonded complexes are not necessarily the most stable ones. In particular, in the most stable 1:1 complex structure the main stabilizing factors come from van der Waals interactions. The high accuracy of the calcd. binding energies provides a reliable basis to discuss the abundance of these clusters in the atm. We predict concns. up to 9.24 × 1015, 3.91 × 1014, and 2.02 × 1914 mols.·cm-3 for water dimer, trimer, and tetramer in very hot and humid conditions and that the concns. of these clusters would remain significant up to 10 km of altitude in the Earth's atm. The concn. of O3···H2O is predicted to be between 1 and 2 orders of magnitude higher than previous estn. from the literature: up to 5.74 × 108 mols.·cm-3 in very hot and humid conditions at ground level and up to 1.56 × 107 mols.·cm-3 at 10 km of altitude of the Earth's atm. The concns. of the other ozone-water clusters, O3··(H2O)2, O3···(H2O)3, and O3···(H2O)4, are predicted to be very small or even negligible in the atm.
- 40Larson, L. J.; Kuno, M.; Tao, F. M. Hydrolysis of sulfur trioxide to form sulfuric acid in small water clusters. J. Chem. Phys. 2000, 112 (20), 8830– 8838, DOI: 10.1063/1.48153240https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD3cXivFClsbo%253D&md5=4478be77743b6fb67dce7726c000be41Hydrolysis of sulfur trioxide to form sulfuric acid in small water clustersLarson, Laura J.; Kuno, Mayuso; Tao, Fu-MingJournal of Chemical Physics (2000), 112 (20), 8830-8838CODEN: JCPSA6; ISSN:0021-9606. (American Institute of Physics)The hydrolysis reaction of sulfur trioxide to form sulfuric acid in small water clusters is investigated using d. function theory and ab initio methods. The equil. geometries for the reactant clusters that contain SO3 and one to four water mols., SO3·(H2O)n, n=1-4, as well as the corresponding transition state and product clusters, are calcd. at the levels of B3LYP/6-31+G*, B3LYP/6-311++G**, and MP2/6-311++G**. The relative energies of the reactant, transition state, and product are detd. for each of the four clusters. The energy barrier required to form H2SO4 from the reactant cluster is found to decrease sharply with the no. of water mols. in the cluster. Most significantly, the SO3·(H2O)4 cluster is found to be unstable and to form the ion pair HSO4- and H3O+ with little or no energy barrier. This work reveals the possibility of more pathways for the formation of sulfuric acid than have been previously considered.
- 41Yang, D. Y.; Zhang, S. J.; Niu, T. L.; Wang, Y. J.; Xu, H. L.; Zhang, K. M.; Wu, Y. High-resolution mapping of vehicle emissions of atmospheric pollutants based on large-scale, real-world traffic datasets. Atmos. Chem. Phys. 2019, 19 (13), 8831– 8843, DOI: 10.5194/acp-19-8831-201941https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC1MXhsFClsbbL&md5=4ec8d149d11b50863671ca500f5c72f5High-resolution mapping of vehicle emissions of atmospheric pollutants based on large-scale, real-world traffic datasetsYang, Daoyuan; Zhang, Shaojun; Niu, Tianlin; Wang, Yunjie; Xu, Honglei; Zhang, K. Max; Wu, YeAtmospheric Chemistry and Physics (2019), 19 (13), 8831-8843CODEN: ACPTCE; ISSN:1680-7324. (Copernicus Publications)On-road vehicle emissions are a major contributor to elevated air pollution levels in populous metropolitan areas. We developed a link-level emissions inventory of vehicular pollutants, called EMBEV-Link (Link-level Emission factor Model for the BEijing Vehicle fleet), based on multiple datasets extd. from the extensive road traffic monitoring network that covers the entire municipality of Beijing, China (16 400 km2). We employed the EMBEV-Link model under various traffic scenarios to capture the significant variability in vehicle emissions, temporally and spatially, due to the real-world traffic dynamics and the traffic restrictions implemented by the local government. The results revealed high carbon moNOx ide (CO) and total hydrocarbon (THC) emissions in the urban area (i.e., within the Fifth Ring Road) and during rush hours, both assocd. with the passenger vehicle traffic. By contrast, considerable fractions of nitrogen oxides (NOx), fine particulate matter (PM2.5) and black carbon (BC) emissions were present beyond the urban area, as heavy-duty trucks (HDTs) were not allowed to drive through the urban area during daytime. The EMBEV-Link model indicates that nonlocal HDTs could account for 29% and 38% of estd. total on-road emissions of NOx and PM2.5, which were ignored in previous conventional emission inventories. We further combined the EMBEV-Link emission inventory and a computationally efficient dispersion model, RapidAir, to simulate vehicular NOx concns. at fine resolns. (10 m × 10 m in the entire municipality and 1 m × 1 m in the hotspots). The simulated results indicated a close agreement with ground observations and captured sharp concn. gradients from line sources to ambient areas. During the nighttime when the HDT traffic restrictions are lifted, HDTs could be responsible for approx. 10 μg m-3 of NOx in the urban area. The uncertainties of conventional top-down allocation methods, which were widely used to enhance the spatial resoln. of vehicle emissions, are also discussed by comparison with the EMBEV-Link emission inventory.
- 42Xu, W. Y.; Zhao, C. S.; Ran, L.; Lin, W. L.; Yan, P.; Xu, X. B. SO2 noontime-peak phenomenon in the North China Plain. Atmos. Chem. Phys. 2014, 14 (15), 7757– 7768, DOI: 10.5194/acp-14-7757-201442https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXhs1amu7rN&md5=58dfe1e208074e1caf0a1c9cbd46cf2dSO2 noontime-peak phenomenon in the North China PlainXu, W. Y.; Zhao, C. S.; Ran, L.; Lin, W. L.; Yan, P.; Xu, X. B.Atmospheric Chemistry and Physics (2014), 14 (15), 7757-7768, 12 pp.CODEN: ACPTCE; ISSN:1680-7324. (Copernicus Publications)A phenomenon of frequent noontime SO2 concn. peaks was discovered in a detailed anal. of the SO2 concns. in the North China Plain (NCP). The possible causes and their contributions are analyzed. The impacts of such a phenomenon on the sulfur cycle were studied and the implications of the phenomenon for atm. chem., cloud physics, and climate were discussed. Different from the more common SO2 diurnal patterns with high nighttime concns., NCP witnessed high frequencies of noontime SO2 peaks, with an occurrence frequency of 50 to 72% at four stations. Down mixing of elevated pollution layers, plume transport processes, mountain-valley winds, and fog/high RH haze events were the possible causes. The contribution of each process varies from day to day and from station to station, however, none of those four processes can be neglected. SO2 peaks occurring during noontime instead of nighttime will lead to a 13 to 35% increase in sulfur dry deposition, a 9 to 23% increase in gas phase oxidn., and an 8 to 33% increase in aq. phase conversions, which will increase the hygroscopicity and the light scattering of aerosols, thus having important impacts on atm. chem., cloud physics, and climate.
- 43Liu, J.; Mauzerall, D. L.; Chen, Q.; Zhang, Q.; Song, Y.; Peng, W.; Klimont, Z.; Qiu, X. H.; Zhang, S. Q.; Hu, M.; Lin, W. L.; Smith, K. R.; Zhu, T. Air pollutant emissions from Chinese households: A major and underappreciated ambient pollution source. Proc. Natl. Acad. Sci. U. S. A. 2016, 113 (28), 7756– 7761, DOI: 10.1073/pnas.160453711343https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC28XhtFentrvE&md5=a900007ac72f2fd7a7492ba12f868e63Air pollutant emissions from Chinese households: A major and underappreciated ambient pollution sourceLiu, Jun; Mauzerall, Denise L.; Chen, Qi; Zhang, Qiang; Song, Yu; Peng, Wei; Klimont, Zbigniew; Qiu, Xinghua; Zhang, Shiqiu; Hu, Min; Lin, Weili; Smith, Kirk R.; Zhu, TongProceedings of the National Academy of Sciences of the United States of America (2016), 113 (28), 7756-7761CODEN: PNASA6; ISSN:0027-8424. (National Academy of Sciences)As part of the 12th Five-Year Plan, the Chinese government has developed air pollution prevention and control plans for key regions with a focus on the power, transport, and industrial sectors. Here, we investigate the contribution of residential emissions to regional air pollution in highly polluted eastern China during the heating season, and find that dramatic improvements in air quality would also result from redn. in residential emissions. We use the Weather Research and Forecasting model coupled with Chem. to evaluate potential residential emission controls in Beijing and in the Beijing, Tianjin, and Hebei (BTH) region. In Jan. and Feb. 2010, relative to the base case, eliminating residential emissions in Beijing reduced daily av. surface PM2.5 (particulate mater with aerodynamic diam. equal or smaller than 2.5 μm) concns. by 14 ± 7 μg·m-3 (22 ± 6% of a baseline concn. of 67 ± 41 μg·m-3; mean ± SD). Eliminating residential emissions in the BTH region reduced concns. by 28 ± 19 μg·m-3 (40 ± 9% of 67 ± 41 μg·m-3), 44 ± 27 μg·m-3 (43 ± 10% of 99 ± 54 μg·m-3), and 25 ± 14 μg·m-3 (35 ± 8% of 70 ± 35 μg·m-3) in Beijing, Tianjin, and Hebei provinces, resp. Annually, elimination of residential sources in the BTH region reduced emissions of primary PM2.5 by 32%, compared with 5%, 6%, and 58% achieved by eliminating emissions from the transportation, power, and industry sectors, resp. We also find air quality in Beijing would benefit substantially from redns. in residential emissions from regional controls in Tianjin and Hebei, indicating the value of policies at the regional level.
- 44Li, R.; Fu, H. B.; Cui, L. L.; Li, J. L.; Wu, Y.; Meng, Y.; Wang, Y. T.; Chen, J. M. The spatiotemporal variation and key factors of SO2 in 336 cities across China. J. Cleaner Prod. 2019, 210, 602– 611, DOI: 10.1016/j.jclepro.2018.11.06244https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC1cXit1eit7rF&md5=ea12483750c7677120be7b3ff532137eThe spatiotemporal variation and key factors of SO2 in 336 cities across ChinaLi, Rui; Fu, Hongbo; Cui, Lulu; Li, Junlin; Wu, Yu; Meng, Ya; Wang, Yutao; Chen, JianminJournal of Cleaner Production (2019), 210 (), 602-611CODEN: JCROE8; ISSN:0959-6526. (Elsevier Ltd.)Sulfur dioxide (SO2) pollution has become a severe concern in China, which is closely linked to human health. Here, the officially released data of SO2 in the 336 prefecture-level cities in 2015 across the whole China were firstly collected to understand the spatiotemporal variation of the SO2 concn. At a national scale, the SO2 concn. was highest in winter, followed by one in spring and autumn, and the lowest one in summer. The spatial econometric models, the geog. wt. regression (GWR) model, and the generalized additive model (GAM) were then applied to examine the interaction of socioeconomic factors (e.g., gross domestic prodn. (GDP)) and the meteorol. indicators (e.g., pptn.) on the SO2 level in the 336 cities over China. The results suggested that the SO2 concn. was neg. assocd. with GDP, pptn., wind speed (WS), and relative humidity (RH), while it showed the pos. relationship with gross industrial prodn. (GIP), population, and temp. GDP in the Jiangsu and Zhejiang provinces presented the neg. correlations with the SO2 concn., suggesting the adaptation of industrial structure has occurred in the developed region. The pos. effect of GIP on the SO2 concn. increased from West China to North China because many energy-intensive industries were concd. on North China. The GAM anal. suggested that the combined effects of the adverse meteorol. condition (e.g., RH = 50-60%) and the higher GIP contributed to severe SO2 pollution. Therefore, the SO2 emission from the heavy industries esp. in NCP should be reduced and many energy-intensive plants in the region should be moved to some cities with favorable diffusion condition.
- 45Huang, Q.; Cheng, S. Y.; Perozzi, R. E.; Perozzi, E. F. Use of a MM5-CAMx-PSAT Modeling System to Study SO2 Source Apportionment in the Beijing Metropolitan Region. Environ. Model. Assess. 2012, 17 (5), 527– 538, DOI: 10.1007/s10666-012-9312-8There is no corresponding record for this reference.
- 46Kampa, M.; Castanas, E. Human health effects of air pollution. Environ. Pollut. 2008, 151 (2), 362– 367, DOI: 10.1016/j.envpol.2007.06.01246https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD1cXhsVGqsbg%253D&md5=6ca25818591d347f98c3f3bc0bcfbd36Human health effects of air pollutionKampa, Marilena; Castanas, EliasEnvironmental Pollution (Amsterdam, Netherlands) (2008), 151 (2), 362-367CODEN: ENPOEK; ISSN:0269-7491. (Elsevier B.V.)A review. Hazardous chems. escape to the environment by a no. of natural and/or anthropogenic activities and may cause adverse effects on human health and the environment. Increased combustion of fossil fuels in the last century is responsible for the progressive change in the atm. compn. Air pollutants, such as carbon monoxide (CO), sulfur dioxide (SO2), nitrogen oxides (NOx), volatile org. compds. (VOCs), ozone (O3), heavy metals, and respirable particulate matter (PM2.5 and PM10), differ in their chem. compn., reaction properties, emission, time of disintegration and ability to diffuse in long or short distances. Air pollution has both acute and chronic effects on human health, affecting a no. of different systems and organs. It ranges from minor upper respiratory irritation to chronic respiratory and heart disease, lung cancer, acute respiratory infections in children and chronic bronchitis in adults, aggravating pre-existing heart and lung disease, or asthmatic attacks. In addn., short- and long-term exposures have also been linked with premature mortality and reduced life expectancy. These effects of air pollutants on human health and their mechanism of action are briefly discussed. The effect of air pollutants on human health and underlying mechanisms of cellular action are discussed.
- 47Zhong, Q. R.; Shen, H. Z.; Yun, X.; Chen, Y. L.; Ren, Y. A.; Xu, H. R.; Shen, G. F.; Ma, J. M.; Tao, S. Effects of International Fuel Trade on Global Sulfur Dioxide Emissions. Environ. Sci. Technol. Lett. 2019, 6 (12), 727– 731, DOI: 10.1021/acs.estlett.9b0061747https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC1MXitFCns7nM&md5=3495e2a64b0aeb64a3213e8fc7e52e4bEffects of International Fuel Trade on Global Sulfur Dioxide EmissionsZhong, Qirui; Shen, Huizhong; Yun, Xiao; Chen, Yilin; Ren, Yu'ang; Xu, Haoran; Shen, Guofeng; Ma, Jianmin; Tao, ShuEnvironmental Science & Technology Letters (2019), 6 (12), 727-731CODEN: ESTLCU; ISSN:2328-8930. (American Chemical Society)Fossil fuel combustion is the dominant source of global sulfur dioxide (SO2) emissions. With rapid globalization, the expansion of international fuel trade may have profound impacts on SO2 emissions due to the mixing and the spatial reallocation of fuels with varied quality (e.g., sulfur contents), which has not been clearly addressed. Here, by introducing international fuel trade and three addnl. counterfactual scenarios, we first assessed the impacts of fuel trade on global SO2 emissions for the period 1980-2030. In 2014 international fuel trade caused an increase in global SO2 emissions from hard coal and oil consumption by 4% and 71%, resp., with stronger influences found for individual countries. By changing the fuel trade choice, global SO2 emissions attributable to fuel trade would be reduced by 78%. We also showed that such effects of fuel trade on SO2 emissions continuously increased from 1980 to 2014 and will keep increasing in the foreseeable future due to more frequent fuel trading under globalization.
- 48Klimont, Z.; Smith, S. J.; Cofala, J. The last decade of global anthropogenic sulfur dioxide: 2000–2011 emissions. Environ. Res. Lett. 2013, 8 (1), 014003, DOI: 10.1088/1748-9326/8/1/01400348https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXhsFeisb3F&md5=0baecab9161b1fbb9a2695fc697675c6The last decade of global anthropogenic sulfur dioxide: 2000-2011 emissionsKlimont, Z.; Smith, S. J.; Cofala, J.Environmental Research Letters (2013), 8 (1), 014003CODEN: ERLNAL; ISSN:1748-9326. (IOP Publishing Ltd.)The evolution of global and regional anthropogenic SO2 emissions in the last decade has been estd. through a bottom-up calcn. After increasing until about 2006, we est. a declining trend continuing until 2011. However, there is strong spatial variability, with North America and Europe continuing to reduce emissions, with an increasing role of Asia and international shipping. China remains a key contributor, but the introduction of stricter emission limits followed by an ambitious program of installing flue gas desulfurization on power plants resulted in a significant decline in emissions from the energy sector and stabilization of total Chinese SO2 emissions. Comparable mitigation strategies are not yet present in several other Asian countries and industrial sectors in general, while emissions from international shipping are expected to start declining soon following an international agreement to reduce the sulfur content of fuel oil. The estd. trends in global SO2 emissions are within the range of representative concn. pathway (RCP) projections and the uncertainty previously estd. for the year 2005.
- 49Su, S. S.; Li, B. G.; Cui, S. Y.; Tao, S. Sulfur Dioxide Emissions from Combustion in China: From 1990 to 2007. Environ. Sci. Technol. 2011, 45 (19), 8403– 8410, DOI: 10.1021/es201656f49https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3MXhtFWmu7rP&md5=7785e0087833046ebe359711e853d393Sulfur Dioxide Emissions from Combustion in China: From 1990 to 2007Su, Shen-Shen; Li, Beng-Ang; Cui, Si-Yu; Tao, ShuEnvironmental Science & Technology (2011), 45 (19), 8403-8410CODEN: ESTHAG; ISSN:0013-936X. (American Chemical Society)Since 2005, China has become the largest SO2 emitter in the world and aggressive deployment of flue gas desulfurization (FGD) at coal-fired power generating facilities appeared in China when facing the formidable pressure of environment pollution. This work estd. annual SO2 emissions from combustion sources at the Province level in China from 1990 to 2007 using updated data investigations. The method of transportation matrix was used to better understand the coal S content in consuming provinces which improved the inventory. Total combustion-related emissions in 2007 were 28.3 Tg, half of which was contributed by coal-fired power generating facilities. Industrial boiler coal combustion and residential coal consumed for centralized heating were responsible for another 32% of total emissions. From 1990 to 2007, annual SO2 emissions fluctuated with 2 peaks (1996 and 2006); total emissions doubled from 15.4 to 30.8 Tg, at an annual 4.4% growth rate (6.3% since 2000). Due to the extensive use of FGD technol. and the phase-out of small, highly emitting units, SO2 emissions began to decrease after 2006. Differences among literature-reported ests. highlight a great need for addnl. research to reduce uncertainties with more detailed information on key sources and actual device operation.
- 50Zheng, H. T.; Cai, S. Y.; Wang, S. X.; Zhao, B.; Chang, X.; Hao, J. M. Development of a unit-based industrial emission inventory in the Beijing-Tianjin-Hebei region and resulting improvement in air quality modeling. Atmos. Chem. Phys. 2019, 19 (6), 3447– 3462, DOI: 10.5194/acp-19-3447-201950https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC1MXpt1ynu7s%253D&md5=4b61fefcf1a516822a4c1bd7f4d56db1Development of a unit-based industrial emission inventory in the Beijing-Tianjin-Hebei region and resulting improvement in air quality modelingZheng, Haotian; Cai, Siyi; Wang, Shuxiao; Zhao, Bin; Chang, Xing; Hao, JimingAtmospheric Chemistry and Physics (2019), 19 (6), 3447-3462CODEN: ACPTCE; ISSN:1680-7324. (Copernicus Publications)The Beijing-Tianjin-Hebei (BTH) region is a metropolitan area with the most severe fine particle (PM2.5) pollution in China. An accurate emission inventory plays an important role in air pollution control policy making. In this study, we develop a unit-based emission inventory for industrial sectors in the BTH region, including power plants, industrial boilers, steel, non-ferrous metal smelting, coking plants, cement, glass, brick, lime, ceramics, refineries, and chem. industries, based on detailed information for each enterprise, such as location, annual prodn., prodn. technol./processes, and air pollution control facilities. In the BTH region, the emissions of sulfur dioxide (SO2), nitrogen oxide (NOx), particulate matter with diam. less than 10 μm (PM10), PM2.5, black carbon (BC), org. carbon (OC), and non-methane volatile org. compds. (NMVOCs) from industrial sectors were 869, 1164, 910, 622, 71, 63, and 1390 kt in 2014, resp., accounting for a resp. 61 %, 55 %, 62 %, 56 %, 58 %, 22 %, and 36 % of the total emissions. Compared with the traditional proxy-based emission inventory, much less emissions in the high-resoln. unit-based inventory are allocated to the urban centers due to the accurate positioning of industrial enterprises. We apply the Community Multi-scale Air Quality (CMAQ; version 5.0.2) model simulation to evaluate the unit-based inventory. The simulation results show that the unit-based emission inventory shows better performance with respect to both PM2.5 and gaseous pollutants than the proxy-based emission inventory. The normalized mean biases (NMBs) are 81 %, 21 %, 1 %, and -7 % for the concns. of SO2, NO2, ozone (O3), and PM2.5, resp., with the unit-based inventory, in contrast to 124 %, 39 %, -8 %, and 9 % with the proxy-based inventory; furthermore, the concn. gradients of PM2.5, which are defined as the ratio of the urban concn. to the suburban concn., are 1.6, 2.1, and 1.5 in Jan. and 1.3, 1.5, and 1.3 in July, for simulations with the unit-based inventory, simulations with the proxy-based inventory, and observations, resp., in Beijing. For O3, the corresponding gradients are 0.7, 0.5, and 0.9 in Jan. and 0.9, 0.8, and 1.1 in July, implying that the unit-based emission inventory better reproduces the distributions of pollutant emissions between the urban and suburban areas.
- 51Rohrer, F.; Lu, K. D.; Hofzumahaus, A.; Bohn, B.; Brauers, T.; Chang, C. C.; Fuchs, H.; Haseler, R.; Holland, F.; Hu, M.; Kita, K.; Kondo, Y.; Li, X.; Lou, S. R.; Oebel, A.; Shao, M.; Zeng, L. M.; Zhu, T.; Zhang, Y. H.; Wahner, A. Maximum efficiency in the hydroxyl-radical-based self-cleansing of the troposphere. Nat. Geosci. 2014, 7 (8), 559– 563, DOI: 10.1038/ngeo219951https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXhtFGqsbjE&md5=6f85b899a8a8d644714c662d6b227355Maximum efficiency in the hydroxyl-radical-based self-cleansing of the troposphereRohrer, Franz; Lu, Keding; Hofzumahaus, Andreas; Bohn, Birger; Brauers, Theo; Chang, Chih-Chung; Fuchs, Hendrik; Haeseler, Rolf; Holland, Frank; Hu, Min; Kita, Kazuyuki; Kondo, Yutaka; Li, Xin; Lou, Shengrong; Oebel, Andreas; Shao, Min; Zeng, Limin; Zhu, Tong; Zhang, Yuanhang; Wahner, AndreasNature Geoscience (2014), 7 (8), 559-563CODEN: NGAEBU; ISSN:1752-0894. (Nature Publishing Group)The removal of trace gases from the troposphere is, in most cases, initialized by reactions with hydroxyl radicals, and the products of these reactions are eventually deposited on the Earth's surface. The concn. of these hydroxyl radicals is therefore a measure of atm. self-cleansing. In theory, hydroxyl-radical concns. can be enhanced by the recycling of some of the reaction products. The only known efficient recycling process involves nitrogen oxide and leads to prodn. of ozone, yet observations in regions with high hydrocarbon and low nitrogen oxide concns. show substantially elevated hydroxyl-radical concns., up to ten times higher than expected. If we normalize obsd. hydroxyl-radical concns. to the max. achievable in model calcns. with variable nitrogen oxide concns., this photochem. coordinate system uncovers a common feature in almost all of these observations: even in the presence of inadequate amts. of nitrogen oxides, hydroxyl-radical concns. are enhanced to the theor. max. obtainable at very much higher nitrogen oxide concns. This means that this important part of the self-cleansing capability of the atm. is working at max. efficiency even in regions with a high burden of biogenic hydrocarbons and low nitrogen oxide concn. Since these processes do not involve nitrogen oxides, tropospheric ozone prodn. is greatly reduced compared with the expectation from current theory.
- 52Lu, K. D.; Rohrer, F.; Holland, F.; Fuchs, H.; Brauers, T.; Oebel, A.; Dlugi, R.; Hu, M.; Li, X.; Lou, S. R.; Shao, M.; Zhu, T.; Wahner, A.; Zhang, Y. H.; Hofzumahaus, A. Nighttime observation and chemistry of HOx in the Pearl River Delta and Beijing in summer 2006. Atmos. Chem. Phys. 2014, 14 (10), 4979– 4999, DOI: 10.5194/acp-14-4979-201452https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXht1CmtrrM&md5=4475da4c4f59c783c3b444d95dddba8bNighttime observation and chemistry of HOx in the Pearl River Delta and Beijing in summer 2006Lu, K. D.; Rohrer, F.; Holland, F.; Fuchs, H.; Brauers, T.; Oebel, A.; Dlugi, R.; Hu, M.; Li, X.; Lou, S. R.; Shao, M.; Zhu, T.; Wahner, A.; Zhang, Y. H.; Hofzumahaus, A.Atmospheric Chemistry and Physics (2014), 14 (10), 4979-4999, 21 pp.CODEN: ACPTCE; ISSN:1680-7324. (Copernicus Publications)Nighttime HOx chem. was investigated in two ground-based field campaigns (PRIDE-PRD2006 and CAREBEIJING2006) in summer 2006 in China by comparison of measured and modeled concn. data of OH and HO2. The measurement sites were located in a rural environment in the Pearl River Delta (PRD) under urban influence and in a suburban area close to Beijing, resp. In both locations, significant nighttime concns. of radicals were obsd. under conditions with high total OH reactivities of about 40-50 s-1 in PRD and 25 s-1 near Beijing. For OH, the nocturnal concns. were within the range of (0.5-3) × 106 cm-3, implying a significant nighttime oxidn. rate of pollutants on the order of several ppb per h. The measured nighttime concn. of HO2 was about (0.2-5) × 108 cm-3, contg. a significant, model-estd. contribution from RO2 as an interference. A chem. box model based on an established chem. mechanism is capable of reproducing the measured nighttime values of the measured peroxy radicals and kOH, but underestimates in both field campaigns the obsd. OH by about 1 order of magnitude. Sensitivity studies with the box model demonstrate that the OH discrepancy between measured and modeled nighttime OH can be resolved, if an addnl. ROx prodn. process (about 1 ppb h-1) and addnl. recycling (RO2 → HO2 → OH) with an efficiency equiv. to 1 ppb NO is assumed. The addnl. recycling mechanism was also needed to reproduce the OH observations at the same locations during daytime for conditions with NO mixing ratios below 1 ppb. This could be an indication that the same missing process operates at day and night. In principle, the required primary ROx source can be explained by ozonolysis of terpenoids, which react faster with ozone than with OH in the nighttime atm. However, the amt. of these highly reactive biogenic volatile org. compds. (VOCs) would require a strong local source, for which there is no direct evidence. A more likely explanation for an addnl. ROx source is the vertical downward transport of radical reservoir species in the stable nocturnal boundary layer. Using a simplified one-dimensional two-box model, it can be shown that ground-based NO emissions could generate a large vertical gradient causing a downward flux of peroxy acetic nitrate (PAN) and peroxymethacryloyl nitrate (MPAN). The downward transport and the following thermal decompn. of these compds. can produce up to 0.3 ppb h-1 radicals in the atm. layer near the ground. Although this rate is not sufficient to explain the complete OH discrepancy, it indicates the potentially important role of vertical transport in the lower nighttime atm.
- 53Tan, Z.; Fuchs, H.; Lu, K.; Hofzumahaus, A.; Bohn, B.; Broch, S.; Dong, H.; Gomm, S.; Häseler, R.; He, L.; Holland, F.; Li, X.; Liu, Y.; Lu, S.; Rohrer, F.; Shao, M.; Wang, B.; Wang, M.; Wu, Y.; Zeng, L.; Zhang, Y.; Wahner, A.; Zhang, Y. Radical chemistry at a rural site (Wangdu) in the North China Plain: observation and model calculations of OH, HO2 and RO2 radicals. Atmos. Chem. Phys. 2017, 17 (1), 663– 690, DOI: 10.5194/acp-17-663-201753https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2sXosVCht7s%253D&md5=7771064fa2e60fb9c13aae2534101078Radical chemistry at a rural site (Wangdu) in the North China Plain: observation and model calculations of OH, HO2 and RO2 radicalsTan, Zhaofeng; Fuchs, Hendrik; Lu, Keding; Hofzumahaus, Andreas; Bohn, Birger; Broch, Sebastian; Dong, Huabin; Gomm, Sebastian; Haseler, Rolf; He, Lingyan; Holland, Frank; Li, Xin; Liu, Ying; Lu, Sihua; Rohrer, Franz; Shao, Min; Wang, Baolin; Wang, Ming; Wu, Yusheng; Zeng, Limin; Zhang, Yinsong; Wahner, Andreas; Zhang, YuanhangAtmospheric Chemistry and Physics (2017), 17 (1), 663-690CODEN: ACPTCE; ISSN:1680-7324. (Copernicus Publications)A comprehensive field campaign was carried out in summer 2014 in Wangdu, located in the North China Plain. A month of continuous OH, HO2 and RO2 measurements was achieved. Observations of radicals by the laser-induced fluorescence (LIF) technique revealed daily max. concns. between (5-15) ×106 cm-3, (3-14) ×108 cm-3 and (3-15) ×108 cm-3 for OH, HO2 and RO2, resp. Measured OH reactivities (inverse OH lifetime) were 10 to 20 s-1 during daytime. The chem. box model RACM2, including the Leuven isoprene mechanism (LIM), was used to interpret the obsd. radical concns. As inprevious field campaigns in China, modeled and measured OH concns. agree for NO mixing ratios higher than1 ppbv, but systematic discrepancies are obsd. in the afternoon for NO mixing ratios of less than 300 pptv (themodel-measurement ratio is between 1.4 and 2 in this case).If addnl. OH recycling equiv. to 100 pptv NO is assumed, the model is capable of reproducing the obsd. OH, HO2 and RO2 concns. for conditions of high volatile org. compd. (VOC) and low NOx concns. For HO2, good agreement is found between modelled and obsd. concns. during day and night. In the case of RO2, the agreement between model calcns. and measurements is good in the late afternoon when NO concns. are below 0.3 ppbv. A significant model under prediction of RO2 by a factor of 3 to 5 is found in the morning at NO concns. higher than 1 ppbv, which can be explained by a missing RO2 source of 2 ppbv h-1. As a consequence, the model under predicts the photochem. net ozone prodn. by 20 ppbv per day, which is a significant portion of the daily integrated ozone prodn. (110 ppbv) derived from the measured HO2 and RO2. The addnl. RO2 prodn. from the photolysis of ClNO2 and missing reactivity can explain about 10% and 20% of the discrepancy, resp. The under prediction of the photochem. ozone prodn. at high NOx found in this study is consistent with the results from other field campaigns in urban environments, which underlines the need for better understanding of the peroxy radical chem. for high NOx conditions.
- 54Tan, Z. F.; Rohrer, F.; Lu, K. D.; Ma, X. F.; Bohn, B.; Broch, S.; Dong, H. B.; Fuchs, H.; Gkatzelis, G. I.; Hofzumahaus, A.; Holland, F.; Li, X.; Liu, Y.; Liu, Y. H.; Novelli, A.; Shao, M.; Wang, H. C.; Wu, Y. S.; Zeng, L. M.; Hu, M.; Kiendler-Scharr, A.; Wahner, A.; Zhang, Y. H. Wintertime photochemistry in Beijing: observations of ROx radical concentrations in the North China Plain during the BEST-ONE campaign. Atmos. Chem. Phys. 2018, 18 (16), 12391– 12411, DOI: 10.5194/acp-18-12391-201854https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC1cXhvFKqtbzE&md5=d83340b3224af51c8a3d6889da7f504cWintertime photochemistry in Beijing: observations of ROx radical concentrations in the North China Plain during the BEST-ONE campaignTan, Zhaofeng; Rohrer, Franz; Lu, Keding; Ma, Xuefei; Bohn, Birger; Broch, Sebastian; Dong, Huabin; Fuchs, Hendrik; Gkatzelis, Georgios I.; Hofzumahaus, Andreas; Holland, Frank; Li, Xin; Liu, Ying; Liu, Yuhan; Novelli, Anna; Shao, Min; Wang, Haichao; Wu, Yusheng; Zeng, Limin; Hu, Min; Kiendler-Scharr, Astrid; Wahner, Andreas; Zhang, YuanhangAtmospheric Chemistry and Physics (2018), 18 (16), 12391-12411CODEN: ACPTCE; ISSN:1680-7324. (Copernicus Publications)The first wintertime in situ measurements of hydroxyl (OH), hydroperoxy (HO2) and org. peroxy (RO2) radicals (ROx = OH + HO2 + RO2) in combination with observations of total reactivity of OH radicals, kOH in Beijing are presented. The field campaign "Beijing winter fine particle STudy - Oxidn., Nucleation and light Extinctions" (BEST-ONE) was conducted at the suburban site Huairou near Beijing from Jan. to March 2016. OH radical concns. at noontime ranged from 2.4 x 106 cm-3 in severely polluted air (kOH ∼ 27 s-1) to 3.6 × 106 cm-3 in relatively clean air (kOH ∼ 5 s-1). These values are nearly 2-fold larger than OH concns. obsd. in previous winter campaigns in Birmingham, Tokyo, and New York City. Other important radical sources were alkene ozonolysis (28%) and photolysis of oxygenated org. compds. (24%). A box model was used to simulate the OH, HO2 and RO2 concns. based on the observations of their long-lived precursors. The model was capable of reproducing the obsd. diurnal variation of the OH and peroxy radicals during clean days with a factor of 1.5. The OH concns. obsd. in the presence of large OH reactivities indicate that atm. trace gas oxidn. by photochem. processes can be highly effective even during wintertime, thereby facilitating the vigorous formation of secondary pollutants.
- 55Lu, K.; Fuchs, H.; Hofzumahaus, A.; Tan, Z.; Wang, H.; Zhang, L.; Schmitt, S. H.; Rohrer, F.; Bohn, B.; Broch, S.; Dong, H.; Gkatzelis, G. I.; Hohaus, T.; Holland, F.; Li, X.; Liu, Y.; Liu, Y.; Ma, X.; Novelli, A.; Schlag, P.; Shao, M.; Wu, Y.; Wu, Z.; Zeng, L.; Hu, M.; Kiendler-Scharr, A.; Wahner, A.; Zhang, Y. Fast Photochemistry in Wintertime Haze: Consequences for Pollution Mitigation Strategies. Environ. Sci. Technol. 2019, 53 (18), 10676– 10684, DOI: 10.1021/acs.est.9b0242255https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC1MXhsFyrurzN&md5=7a4729a7189a2c0bafc3c6c03ef62c38Fast Photochemistry in Wintertime Haze: Consequences for Pollution Mitigation StrategiesLu, Keding; Fuchs, Hendrik; Hofzumahaus, Andreas; Tan, Zhaofeng; Wang, Haichao; Zhang, Lin; Schmitt, Sebastian H.; Rohrer, Franz; Bohn, Birger; Broch, Sebastian; Dong, Huabin; Gkatzelis, Georgios I.; Hohaus, Thorsten; Holland, Frank; Li, Xin; Liu, Ying; Liu, Yuhan; Ma, Xuefei; Novelli, Anna; Schlag, Patrick; Shao, Min; Wu, Yusheng; Wu, Zhijun; Zeng, Limin; Hu, Min; Kiendler-Scharr, Astrid; Wahner, Andreas; Zhang, YuanhangEnvironmental Science & Technology (2019), 53 (18), 10676-10684CODEN: ESTHAG; ISSN:0013-936X. (American Chemical Society)In contrast to summer smog, the contribution of photochem. to the formation of winter haze in northern mid-to-high latitude is generally assumed to be minor due to reduced solar UV and water vapor concns. Our comprehensive observations of atm. radicals and relevant parameters during several haze events in winter 2016 Beijing, however, reveal surprisingly high hydroxyl radical oxidn. rates up to 15 ppbv/h, which is comparable to the high values reported in summer photochem. smog and is two to three times larger than those detd. in previous observations during winter in Birmingham. The active photochem. facilitates the prodn. of secondary pollutants. It is mainly initiated by the photolysis of nitrous acid and ozonolysis of olefins and maintained by an extremely efficiently radical cycling process driven by nitric oxide. This boosted radical recycling generates fast photochem. ozone prodn. rates that are again comparable to those during summer photochem. smog. The formation of ozone, however, is currently masked by its efficient chem. removal by nitrogen oxides contributing to the high level of wintertime particles. The future emission regulations, such as the redn. of nitrogen oxide emissions, therefore are facing the challenge of reducing haze and avoiding an increase in ozone pollution at the same time. Efficient control strategies to mitigate winter haze in Beijing may require measures similar as implemented to avoid photochem. smog in summer.
- 56Srivastava, R. K.; Miller, C. A.; Erickson, C.; Jambhekar, R. Emissions of sulfur trioxide from coal-fired power plants. J. Air Waste Manage. Assoc. 2004, 54 (6), 750– 762, DOI: 10.1080/10473289.2004.1047094356https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD2cXlvFWjtrY%253D&md5=f04d2a848308c69692c247d40e63b2f5Emissions of sulfur trioxide from coal-fired power plantsSrivastava, R. K.; Miller, C. A.; Erickson, C.; Jambhekar, R.Journal of the Air & Waste Management Association (2004), 54 (6), 750-762CODEN: JAWAFC; ISSN:1096-2247. (Air & Waste Management Association)A review concerning air pollution and its control in relation to SO3 and H2SO4 flue gas emissions from coal-fired power generation facilities is given. Topics discussed include: health and environmental effects; impacts on facility hardware; regulatory overview; SO3 formation (in-boiler, in selective catalytic redn. reactors); SO3 depletion or conversion to H2SO4 (processes in air pre-heaters, localized H2SO4 condensation in ducts between air pre-heater and particulate matter control, fly ash H2SO4 adsorption and removal in PM control equipment, aerosol formation in wet flue gas desulfurization systems); SO3 measurement; and mitigating SO3 emissions (alkali addn. to furnace, alkali injection after the furnace, NH3 injection before the electrostatic precipitator, fuel switching and blending, wet electrostatic precipitators, changing air pre-heater operation).
- 57Yang, Z. D.; Zheng, C. H.; Zhang, X. F.; Zhou, H.; Silva, A. A.; Liu, C. Y.; Snyder, B.; Wang, Y.; Gao, X. Challenge of SO3 removal by wet electrostatic precipitator under simulated flue gas with high SO3 concentration. Fuel 2018, 217, 597– 604, DOI: 10.1016/j.fuel.2017.12.12557https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC1cXlvFemsw%253D%253D&md5=9d2b2f6f0fc83fb48e33a3115b527055Challenge of SO3 removal by wet electrostatic precipitator under simulated flue gas with high SO3 concentrationYang, Zhengda; Zheng, Chenghang; Zhang, Xuefeng; Zhou, Hao; Silva, Anthony A.; Liu, Chungyi; Snyder, Bob; Wang, Yi; Gao, XiangFuel (2018), 217 (), 597-604CODEN: FUELAC; ISSN:0016-2361. (Elsevier Ltd.)Wet electrostatic precipitators (WESP) have been proven to be a promising technol. for the removal of sulfuric acid mist from flue gases. Recent studies indicate that WESPs, when mitigating sulfuric acid mist, can be less effective on systems that burn high sulfur content fuel. This paper reports on a pilot-scale WESP used to investigate SO3 removal with high SO3 concn. Both mass concn. of SO3 and no. concn. of sulfuric acid mist were measured. Two key parameters, i.e., elec. characteristics and gas loading, were studied to evaluate their effects on SO3 removal efficiency under severe corona suppression conditions. Results showed that the max. corona current was reduced by 83.1% when the WESP inlet SO3 concn. increased from 0 to 5c0, and the corresponding SO3 removal efficiency decreased from 74.5% to 54.2%. SO3 removal efficiency can be improved by increasing corona power and reducing gas velocity. A comprehensive method was proposed to enhance SO3 removal efficiency, with removal efficiencies greater than 90% using proper electrode configurations and lower velocity under a pilot plant condition. In addn., other challenges including new ultra-fine mist generation, material corrosion and insulator failure are summarized.
- 58Guo, Y.; Yan, C.; Li, C.; Feng, Z.; Zhou, Y.; Lin, Z.; Dada, L.; Stolzenburg, D.; Yin, R.; Kontkanen, J.; Daellenbach, K. R.; Kangasluoma, J.; Yao, L.; Chu, B.; Wang, Y.; Cai, R.; Bianchi, F.; Liu, Y.; Kulmala, M. Atmos. Chem. Phys. Discuss. 2020, DOI: 10.5194/acp-2019-1111There is no corresponding record for this reference.
- 59Yao, L.; Wang, M.-Y.; Wang, X.-K.; Liu, Y.-J.; Chen, H.-F.; Zheng, J.; Nie, W.; Ding, A.-J.; Geng, F.-H.; Wang, D.-F.; Chen, J.-M.; Worsnop, D. R.; Wang, L. Detection of atmospheric gaseous amines and amides by a high-resolution time-of-flight chemical ionization mass spectrometer with protonated ethanol reagent ions. Atmos. Chem. Phys. 2016, 16 (22), 14527– 14543, DOI: 10.5194/acp-16-14527-201659https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2sXhs1yhs70%253D&md5=e2444c87a5de006e4001fee14d253b22Detection of atmospheric gaseous amines and amides by a high-resolution time-of-flight chemical ionization mass spectrometer with protonated ethanol reagent ionsYao, Lei; Wang, Ming-Yi; Wang, Xin-Ke; Liu, Yi-Jun; Chen, Hang-Fei; Zheng, Jun; Nie, Wei; Ding, Ai-Jun; Geng, Fu-Hai; Wang, Dong-Fang; Chen, Jian-Min; Worsnop, Douglas R.; Wang, LinAtmospheric Chemistry and Physics (2016), 16 (22), 14527-14543CODEN: ACPTCE; ISSN:1680-7324. (Copernicus Publications)Amines and amides are important atm. org.-nitrogen compds. but high time resoln., highly sensitive, and simultaneous ambient measurements of these species are rather sparse. Here, we present the development of a high-resoln. time-of-flight chem. ionization mass spectrometer (HR-ToF-CIMS) method, utilizing protonated ethanol as reagent ions to simultaneously detect atm. gaseous amines (C1 to C6) and amides (C1 to C6). This method possesses sensitivities of 5.6-19.4 Hz pptv-1 for amines and 3.8-38.0 Hz pptv-1 for amides under total reagent ion signals of ∼ 0.32 MHz. Meanwhile, the detection limits were 0.10-0.50 pptv for amines and 0.29-1.95 pptv for amides at 3σ of the background signal for a 1 min integration time. Controlled characterization in the lab. indicates that relative humidity has significant influences on the detection of amines and amides, whereas the presence of orgs. has no obvious effects. Ambient measurements of amines and amides utilizing this method were conducted from 25 July to 25 August 2015 in urban Shanghai, China. While the concns. of amines ranged from a few parts per trillion by vol. to hundreds of parts per trillion by vol., concns. of amides varied from tens of parts per trillion by vol. to a few ppb by vol. Among the C1- to C6-amines, the C2-amines were the dominant species with concns. up to 130 pptv. For amides, the C3-amides (up to 8.7 ppb) were the most abundant species. The diurnal and backward trajectory anal. profiles of amides suggest that in addn. to the secondary formation of amides in the atm., industrial emissions could be important sources of amides in urban Shanghai. During the campaign, photo-oxidn. of amines and amides might be a main loss pathway for them in daytime, and wet deposition was also an important sink.
- 60Liu, L.; Zhong, J.; Vehkamaki, H.; Kurten, T.; Du, L.; Zhang, X.; Francisco, J. S.; Zeng, X. C. Unexpected quenching effect on new particle formation from the atmospheric reaction of methanol with SO3. Proc. Natl. Acad. Sci. U. S. A. 2019, 116 (50), 24966– 24971, DOI: 10.1073/pnas.191545911660https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC1MXitl2hurvO&md5=148bbaeaab5d9765173c8b9a242fb57dUnexpected quenching effect on new particle formation from the atmospheric reaction of methanol with SO3Liu, Ling; Zhong, Jie; VehkamAki, Hanna; Kurten, Theo; Du, Lin; Zhang, Xiuhui; Francisco, Joseph S.; Zeng, Xiao ChengProceedings of the National Academy of Sciences of the United States of America (2019), 116 (50), 24966-24971CODEN: PNASA6; ISSN:0027-8424. (National Academy of Sciences)Despite the high abundance in the atm., alcs. in general and methanol in particular are believed to play a small role in atm. new particle formation (NPF) largely due to the weak binding abilities of alcs. with the major nucleation precursors, e.g., sulfuric acid (SA) and dimethylamine (DMA). Herein, we identify a catalytic reaction that was previously overlooked, namely, the reaction between methanol and SO3, catalyzed by SA, DMA, or water. We found that alcs. can have unexpected quenching effects on the NPF process, particularly in dry and highly polluted regions with high concns. of alcs. Specifically, the catalytic reaction between methanol and SO3 can convert methanol into a less-volatile species-Me hydrogen sulfate (MHS). The latter was initially thought to be a good nucleation agent for NPF. However, our simulation results suggest that the formation of MHS consumes an appreciable amt. of atm. SO3, disfavoring further reactions of SO3 with H2O. Indeed, we found that MHS formation can cause a redn. of SA concn. up to 87%, whereas the nucleation ability of MHS toward new particles is not as good as that of SA. Hence, a high abundance of methanol in the atm. can lower the particle nucleation rate by as much as two orders of magnitude. Such a quenching effect suggests that the recently identified catalytic reactions between alcs. and SO3 need to be considered in atm. modeling to predict SA concn. from SO2, while also account for their potentially neg. effect on NPF.
- 61Olin, M.; Kuuluvainen, H.; Aurela, M.; Kalliokoski, J.; Kuittinen, N.; Isotalo, M.; Timonen, H. J.; Niemi, J. V.; Rönkkö, T.; Dal Maso, M. Traffic-originated nanocluster emission exceeds H2SO4-driven photochemical new particle formation in an urban area. Atmos. Chem. Phys. 2020, 20 (1), 1– 13, DOI: 10.5194/acp-20-1-202061https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB3cXhsVCqsLw%253D&md5=999fb2cb0529e50178519c93b5dd7363Traffic-originated nanocluster emission exceeds H2SO4-driven photochemical new particle formation in an urban areaOlin, Miska; Kuuluvainen, Heino; Aurela, Minna; Kalliokoski, Joni; Kuittinen, Niina; Isotalo, Mia; Timonen, Hilkka J.; Niemi, Jarkko V.; Ronkko, Topi; Dal Maso, MiikkaAtmospheric Chemistry and Physics (2020), 20 (1), 1-13CODEN: ACPTCE; ISSN:1680-7324. (Copernicus Publications)Elevated ambient concns. of sub-3nm particles (nanocluster aerosol, NCA) are generally related to atm. new particle formation events, usually linked with gaseous sulfuric acid (H2SO4) produced via photochem. oxidn. of sulfur dioxide. According to our measurement results of H2SO4 and NCA concns., traffic d., and solar irradiance at an urban traffic site in Helsinki, Finland, the view of aerosol formation in traffic-influenced environments is updated by presenting two sep. and independent pathways of traffic affecting the atm. NCA concns.: by acting as a direct nanocluster source and by influencing the prodn. of H2SO4. Urban aerosol formation studies should, therefore, be updated to include the proposed formation mechanisms. The formation of H2SO4 in urban environments is here sepd. into two routes: primary H2SO4 is formed in hot vehicle exhaust and is converted rapidly to the particle phase; secondary H2SO4 results from the combined effect of emitted gaseous precursors and available solar radiation. A rough estn. demonstrates that ∼85% of the total NCA and ∼68% of the total H2SO4 in urban air at noontime at the measurement site are contributed by traffic, indicating the importance of traffic emissions.
- 62Ronkko, T.; Kuuluvainen, H.; Karjalainen, P.; Keskinen, J.; Hillamo, R.; Niemi, J. V.; Pirjola, L.; Timonen, H. J.; Saarikoski, S.; Saukko, E.; Jarvinen, A.; Silvennoinen, H.; Rostedt, A.; Olin, M.; Yli-Ojanpera, J.; Nousiainen, P.; Kousa, A.; Dal Maso, M. Traffic is a major source of atmospheric nanocluster aerosol. Proc. Natl. Acad. Sci. U. S. A. 2017, 114 (29), 7549– 7554, DOI: 10.1073/pnas.170083011462https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2sXhtFSmtrbK&md5=d763b6f8f4d0abfbfe8372de8ca272ffTraffic is a major source of atmospheric nanocluster aerosolRonkko, Topi; Kuuluvainen, Heino; Karjalainen, Panu; Keskinen, Jorma; Hillamo, Risto; Niemi, Jarkko V.; Pirjola, Liisa; Timonen, Hilkka J.; Saarikoski, Sanna; Saukko, Erkka; Jarvinen, Anssi; Silvennoinen, Henna; Rostedt, Antti; Olin, Miska; Yli-Ojanpera, Jaakko; Nousiainen, Pekka; Kousa, Anu; Dal Maso, MiikkaProceedings of the National Academy of Sciences of the United States of America (2017), 114 (29), 7549-7554CODEN: PNASA6; ISSN:0027-8424. (National Academy of Sciences)In densely populated areas, traffic is a significant source of atm. aerosol particles. Owing to their small size and complicated chem. and phys. characteristics, atm. particles resulting from traffic emissions pose a significant risk to human health and also contribute to anthropogenic forcing of climate. Previous research has established that vehicles directly emit primary aerosol particles and also contribute to secondary aerosol particle formation by emitting aerosol precursors. Here, we extend the urban atm. aerosol characterization to cover nanocluster aerosol (NCA) particles and show that a major fraction of particles emitted by road transportation are in a previously unmeasured size range of 1.3-3.0 nm. For instance, in a semiurban roadside environment, the NCA represented 20-54% of the total particle concn. in ambient air. The obsd. NCA concns. varied significantly depending on the traffic rate and wind direction. The emission factors of NCA for traffic were 2.4·1015 (kgfuel)-1 in a roadside environment, 2.6·1015 (kgfuel)-1 in a street canyon, and 2.9·1015 (kgfuel)-1 in an on-road study throughout Europe. Interestingly, these emissions were not assocd. with all vehicles. In engine lab. expts., the emission factor of exhaust NCA varied from a relatively low value of 1.6·1012 (kgfuel)-1 to a high value of 4.3·1015 (kgfuel)-1. These NCA emissions directly affect particle concns. and human exposure to nanosized aerosol in urban areas, and potentially may act as nanosized condensation nuclei for the condensation of atm. low-volatile org. compds.
Supporting Information
Supporting Information
The Supporting Information is available free of charge at https://pubs.acs.org/doi/10.1021/acs.estlett.0c00615.
Description of the sampling site (Text S1), the nitrate-CI-APi-LTOF mass spectrometer (Text S2), detection of sulfuric acid with nitrate reagent ions (Text S3), detailed calibration experiment for SO3 (Text S4), quantum chemical calculations (Text S6), computational details (Text S7), PM2.5, black carbon, particulate sulfate, trace gases, meteorological parameters, and UVB measurements (Text S8), sub-3 nm particle measurements (Text S9), calculation of condensation sink (Text S10), source identification of SO2 during the winter (Text S11), high-resolution peak fitting of the 32SO3·NO3– peak and its 34SO3·NO3– main isotope peak (Figure S1), schematic of the calibration experiment setup (Figure S2), time series of normalized signals of H2SO4 and SO3, and [H2O] in the calibration experiment (Figure S3), correlation between normalized SO3 signals measured by the CI-APi-LTOF mass spectrometer and SO3 concentrations formed by photo-oxidation of SO2 by OH radicals (Figure S4), optimized structure of the SO3·(NO3–) cluster (Figure S5), lowest-free energy (at 298 K) structure found for SO3·(NO3–)·H2O (Figure S6), averaged mass spectra of atmospheric naturally charged ions for one whole day (November 10, 2018) (Figure S7), median diurnal variation of the concentrations of SO3 and SO2, the mixing layer heights (MLH), intensities of UVB, and wind speeds during the winter (Figure S8), time profile of the SO3 concentration and mass concentration of sulfate in PM2.5 and median diel variation of SO3 and sulfate for all nonhaze days during the winter measurement period (Figure S9), relationship between the atmospheric ion signals of HSO4– and SO3·NO3– during the night (from 18:00 to 5:00 next day) and early morning (5:00–8:00) from November 9 to 22, 2018 (Figure S10), and comparison of the binding thermodynamics of HNO3·(NO3–) and SO3·(NO3–) ion–molecule clusters (Table S1) (PDF)
Terms & Conditions
Most electronic Supporting Information files are available without a subscription to ACS Web Editions. Such files may be downloaded by article for research use (if there is a public use license linked to the relevant article, that license may permit other uses). Permission may be obtained from ACS for other uses through requests via the RightsLink permission system: http://pubs.acs.org/page/copyright/permissions.html.