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Composition, Utilization and Economic Assessment of Torrefaction Condensates

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VTT Technical Research Centre of Finland Ltd., P.O. Box 1000, 02044 VTT, Espoo, Finland
*L. Fagernäs. Telephone: +358 20 722 5453. Fax +358 20 722 7048. E-mail: [email protected]; [email protected]
Cite this: Energy Fuels 2015, 29, 5, 3134–3142
Publication Date (Web):March 31, 2015
https://doi.org/10.1021/acs.energyfuels.5b00004

Copyright © 2015 American Chemical Society. This publication is licensed under these Terms of Use.

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Abstract

The aim of this study was to determine the yields and chemical compositions of condensates formed at torrefaction conditions with different kinds of feedstocks and to assess their utilization from an economic perspective. Test runs for spruce and bamboo were carried out with a slow pyrolysis test rig, and the liquids collected at 20–105, 105–240, and 240–300 °C temperature ranges were analyzed for chemical characteristics and compositions. The results were compared with those obtained earlier for a birch condensate. The mass yields and compositions of condensates differed between the feedstocks and the temperature ranges. The amount of organic compounds in the total condensates was 12–19 wt %. The main compounds were acetic acid, 1-hydroxy-2-propanone, methanol, furfural, and 2-hydroxyacetaldehyde. Total condensates formed at ≤280 °C are promising to be utilized for different purposes, for example as a biopesticide. Higher temperatures are critical, because at 290 °C, strong exothermic reactions occur, which decreases considerably the yield of torrefied material and produces tar containing condensates. It is possible to produce, in addition to biocoal, valuable liquids. Economic assessments were performed for three torrefaction cases without and with the recovery of condensates. The production costs of torrefied pellets can be lowered significantly, for example on the order of 5–10 € MWh–1 in medium scale pellet production, by recovering and selling the condensates to new applications.

Introduction

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Torrefaction is a thermal process where a biomass feedstock is heated at 200 to 300 °C in the absence of oxygen. It has also been called a mild pyrolysis process. (1) The main objective is to use the torrefied biomass (“biocoal”) as a fuel, especially as a pellet for cofiring at pulverized coal power plants. (2) Torrefied pellets have a number of characteristics that offer clear advantages compared with conventional wood-based fuels, such as low moisture content, low uptake of moisture, high energy content, resistance against biological degradation, and good grindability in coal mills. (3-6) Torrefaction gases and vapors are normally burned in a combustion unit with an additional solid or gaseous fuel (biomass, natural gas), to produce the heat energy needed in drying and torrefaction units. (7, 8) The volatiles can also be condensed and potentially utilized for other purposes in a similar fashion as the distillates from the slow pyrolysis process of charcoal production, which are also known as wood vinegars or pyroligneous acid.
Composition and thermal behavior of wood varies between different wood materials, which affects the quality of condensates. (9, 10) Hardwoods contain more hemicelluloses and cellulose than softwoods. (11) Softwood lignin is composed of guaiacyl-type lignin, whereas hardwood lignin contains syringyl and guaiacyl units. Bamboo resembles more woods than nonwoody grasses. (12) The composition of bamboo is, however, dependent on its age and species. (13) Hemicelluloses are the most reactive constituent of wood (9, 14) decomposing in the temperature range of 200–260 °C. The reactive glucuronoxylan (xylan) comprises about 25 wt % of birch and also of bamboo. (11, 12) Cellulose decomposes at 240–350 °C and lignin at about 250–500 °C. (14, 15) According to Prins et al. (9) the kinetics of torrefaction reactions at 230–300 °C can accurately be described by a two-step mechanism. The first step represents the decomposition of hemicelluloses and the second step cellulose decomposition. Hardwood was shown to be much more reactive than softwood, and produced more volatiles than softwood.
So far, torrefaction studies have not been focused on the utilization potential of condensable substances. Instead, the chemical changes in wood caused by torrefaction have been investigated. (1, 16, 17) Recently, for example Shoulaifar et al. (16) studied with several methods the effect of torrefaction temperature on the chemistry of birch wood. The proportions of hemicelluloses, cellulose, lignin, and extractives degraded in torrefaction were determined in detail. Decrease in the components was presented to be attributed not only to volatile production but also char formation.
Wood vinegars from charcoal production are used in agriculture as a fertilizer and growth-promoting agent in Asia. (18) In the studies of Mu et al., (19-21) treatments with bamboo vinegar showed an increase in vegetable growth, and germination and radicle growth for several seeds. The collection temperature was found an important factor for controlling the quality of distillates. (21) Bamboo vinegars collected at temperatures of up to 250 °C promoted radicle and hypocotyl growth, but the vinegar collected from 250 to 400 °C had a strong inhibition on germination and radicle growth.
Wood vinegars have also been reported to be effective fungicides. (22) Bamboo distillates were suggested to be used as coagulating and antifungal agents in natural rubber production to replace mainly formic acid and acetic acid. (23) The distillates showed higher antifungal efficiency than these acids. The efficiency was presented to be affected by phenolic compounds. Bamboo distillates have also been found to inhibit fungi that destroy wood material. (24, 25) They were effective against sap staining fungi and had potential to be used as natural preservatives in wood industries.
Distillates of hardwood are used to repel insects from plants and households. Wood tars produced from alder, larch, and birch were found effective repellents for control of vole in Japan. (26) The distillate produced from birch in barbecue charcoal production in Finland was found a promising source for many kinds of biodegradable pesticides. (27, 28) The birch distillate was considered an effective, noncostly, and environmentally friendly method against molluscs. It showed an herbicidal effect on many species of weeds and was an effective repellent to control the land snail and the Iberian slug.
In our previous studies, birch distillates were studied for chemical composition and utilization potential in plant protection. (29-31) The tar-free distillate produced at ≤280 °C was found to be a promising and marketable product for various purposes. It acted as a repellent against snails and field vole in tests and in practice. The repellence effect was partially due to acetic acid and furfural. The effects of these compounds and also other fractions of birch distillate, on snails, were, however, considerably lower than the effect of the distillate. (32) Tar, which comprised mainly of pyrolytic lignin, was not formed in the distillate until at >280 °C. (31) In wood protection, the tar substances were essential.
The main objectives of the present paper were to determine the yields and chemical compositions of condensates formed at torrefaction conditions (<300 °C) from spruce and bamboo, and to assess their utilization potential. One aim was to compare the results with those of the birch distillate studied earlier by us and used herein as a reference. Spruce was selected to represent softwood, bamboo herbaceous grasses, and birch hardwood. The liquids were collected at different temperature ranges in the test runs carried out with the bench-scale slow pyrolysis equipment. Economic assessments were performed for three torrefaction cases including the recovery of condensates. The work was carried out within the EC 7th FP project “Production of solid sustainable energy carriers from biomass by means of torrefaction” (SECTOR).

Materials and Methods

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Feedstock Properties

The spruce and bamboo feedstocks were reference samples of the SECTOR project and were provided by Energy research Centre of the Netherlands (ECN) to VTT. The chip size of the materials used in the experiments was 30–40 × 10–20 × 5–10 mm. For the feedstocks, physicochemical characteristics were analyzed with following standard methods: moisture content (SFS-EN 14774), ash content (SFS-EN 14775), volatile matter (SFS-EN 15148), fixed carbon (ASTM D 3172), elemental composition (C, H, N; SFS-EN 15104), and sulfur content (SFS-EN 15289).

Torrefaction Test Runs

The raw materials were torrefied in a bench-scale batch testing facility. The equipment was a controlled slow pyrolysis steel reactor heated indirectly in an electric oven (Figure 1). The capacity of the reactor was about 6 kg for feedstock. The torrefied material, condensable liquids, and noncondensable gases produced were recovered. Volatiles and gases were carried with nitrogen gas into a water-cooled vertical condenser. After separation of the liquids, noncondensable gases were introduced into filtering, volume measurement, and gas analysis.

Figure 1

Figure 1. Slow pyrolysis testing facility. 1: Electric oven. 2: Reactor. 3: Cooling section.

In the test runs, the spruce and bamboo feedstocks (3.5–4 kg) were placed on wire levels of the sample holder in the reactor. A stepwise temperature program was used and the condensates were collected at the temperature ranges of 20–105 °C, 105–240 °C, and 240–300 °C. The temperature was raised at 6 °C min−1 and the nitrogen flow rate was 5 L min−1 (NTP, 0 °C, 0.1 MPa). Due to the low heat transfer inside the reactor, the temperature set point was maintained at 105 and 240 °C until the desired temperature was attained inside the reactor. After the heat-up sequence, the reactor was maintained at the final temperature of 300 °C for 1 h. The temperature inside the reactor increased almost linearly. With the heating rate used, the low heat transfer in the reactor did not have a practical significance on condensables when comparing with torrefaction processes.
The birch distillate that was used as a reference in the study, was obtained with the same slow pyrolysis equipment in a test run, where the temperature was raised directly to 300 °C and held for 3 h. In terms of chemicals recovery and environmental load, the aim was to maximize the organic content of the condensate.
The physicochemical characteristics of the torrefied materials were analyzed with the same standard methods presented above for the feedstocks.

Analysis of Condensables

The condensates recovered in the test runs were analyzed for chemical characteristics. The pH was determined with a pH meter, water content by Karl Fischer titration (ASTM E 203), total organic carbon (TOC) with a Shimadzu analyzer, chemical oxygen demand (COD) with a Hach Company spectrophotometer (SFS 5504), and total acid number (TAN) with a 785 DMP Titrino analyzer (ASTM D 664). The organic matter content was calculated by difference (100% – water content).
The main water-soluble organic compounds were analyzed quantitatively by gas chromatography (GC) with a flame ionization detector, using an HP Innowax column (polyethylene glycol, 60 m × 0.25 mm, film thickness 0.25 μm). The oven temperature was programmed at 6 °C min–1 heating rate from 60 °C (hold 1 min) to 230 °C (hold 30 min). Most compounds identified were calibrated by model substances at 500–1000 ppm concentrations, whereas for the main compounds higher concentrations were used. The compounds were of analytical grade. In the analyses, n-butanol was used as an internal standard.
Polycyclic aromatic hydrocarbons (PAHs) were analyzed with GC/mass spectrometry (GC/MS) and the selected ion monitoring (SIM) technique after extraction of the samples with ethanol and hexane and subsequent purification of the extracts by dimethyl sulfoxide extraction, at Nablabs laboratories, Finland. (30)

Economic Assessment

An economic assessment was carried out for three different torrefaction cases including the recovery of condensables. The cases were a stand-alone torrefaction plant (base case), a new sawmill integrated with a new torrefaction plant (sawmill integrate case), and a large overseas stand-alone torrefaction plant (overseas case). The total condensates were recovered. In the base case and the sawmill integrate case, forest fuels were used as raw materials, and in the overseas case, local feedstocks, mainly stem wood, were used. The base case was foreseen as a typical European commercial plant and was chosen as a bench mark.
In the condensate recovery concept, the torrefaction gas was cooled from 280 °C to room temperature (20 °C). The condensation equipment was placed in the torrefaction gas line prior to the combustor. The reduction in the energy content of the torrefaction gas due to the condensation of liquids was compensated with biomass feedstock. The water content of the condensed liquid was about 70 wt %. The water-insoluble substances were decanted out of the product and used as a boiler fuel. The torrefaction gas was cooled directly with the aqueous liquid.
The main mass and energy flows for the cases with or without condensate recovery were calculated. The product of all processes was torrefied pellets. The net calorific value of wood used as a raw material in the torrefaction process and as a boiler fuel was 8.4 MJ kg–1 at 50 wt % moisture content. The net calorific value of torrefied pellets was 22.0 MJ kg–1. Energy need in the drying of wood was for all cases 4.0 MJ kg–1 evaporated H2O using a belt dryer. (33) Torrefied wood was cooled down with steam (directly) and water (indirectly) before the pelletization unit. Power need for grinding was 18 kWhe t–1 and for pelletization 64 kWhe t–1 torrefied pellets.
The economic assessment was mainly based on in-house information on VTT and Pöyry Management Consulting Ltd. (34) Assessment of investment costs was based on a number of feasibility studies and budget offers of commercially available equipment and components. Key input data and base for calculation of production costs are presented in Table 1. These figures reflect mainly costs applied in a Nordic European context. The price of plantation stem wood was based on the worldwide data on pulp wood prices of Pöyry Management Consulting, Ltd. (34) No subsidies were included in the calculations.
Table 1. Key Factors of the Estimate of Production Costs
cost factorvalue
feedstock costs, € MWh–1 
forest residues, up to 150 MWth18
bark16
sawdust16
wood chips (sawmill)18
plantation stem wood15
electricity (with transfer costs), € MWh–160
labor cost (including payroll overheads), € manhour–155
annual capital charges factor0.1175 (10% interest, 20 a)
costs for plant startup, interest during construction21% of plant investment
scale-up exponent0.7
maintenance, insurance, taxes4% of total investment
operating time, h a–18 000
condensate price, € t–1100, 250 or 400
evaluation time, 2012CEPI-index 584.6

Results and Discussion

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Properties of Feedstocks and Torrefied Materials

Physicochemical characteristics of the feedstocks and torrefied materials are presented in Table 2. The main differences between the feedstocks were higher ash, nitrogen and sulfur contents in the bamboo material. Ash forming components in bamboo are mostly alkali metals dominated by potassium, silica, and phosphorus. (35) The ash content varies considerably between different bamboo species and ages. (12) During torrefaction, carbon contents increased and volatile matter contents decreased in the materials. Especially, the ash content of bamboo increased considerably, reducing the energy content of the torrefied product while simultaneously increasing the transportation and handling costs. The sulfur content of torrefied bamboo was higher than that of torrefied spruce.
Table 2. Physicochemical Characteristics of Feedstocks and Torrefied Materials in Test Runs
analysisfeedstock sprucefeedstock bambootorrefied sprucetorrefied bamboo
moisture content, wt %11.512.91.01.1
ash content, wt % of dry wood0.56.50.59.8
volatile matter, wt % of dry wood82.673.961.445.6
fixed carbon,a wt % of dry matter16.919.638.144.6
carbon (C), wt % of dry wood50.646.963.462.0
hydrogen (H), wt % of dry wood5.85.45.44.9
nitrogen (N), wt % of dry wood0.10.30.10.5
sulfur (S), wt % of dry wood0.010.070.010.21
oxygen (O),b wt % of dry wood43423123
a

Determined by difference: 100% – (volatile matter + ash).

b

Determined by difference: 100% − (CHNS + ash).

Mass Yields of the Products

The mass yields of the products in the torrefaction test runs for spruce and bamboo and also for the reference birch are presented in Table 3. The mass yield of torrefied material was considerably higher for spruce than for bamboo and birch, while higher condensate and gas yields were consequently observed for bamboo and birch. This was likely affected by the higher hemicellulose and xylan contents of bamboo and birch in comparison to spruce. For birch, the longer residence time at the final temperature also had a considerable effect on the extent of decomposition, which was clearly reflected in the amount of liquids and gases produced. The mass yields of torrefied materials were lower than what has been generally presented in the literature (1, 3, 17) for wood materials, which was likely due to the high final temperature of 300 °C and the long residence times used.
Table 3. Mass Yields of Products in Torrefaction Test Runs with Different Feedstocks
productsprucebamboobirch (reference)
torrefied material, wt % (on wet input basis)615146
torrefied material, wt % (on dry input basis)695950
total condensate, wt % (on wet input basis)293239
noncondensable gases, wt % (on wet input basis)a101715
a

Calculated by difference: 100% – (torrefied material + total condensate).

Formation of Condensables

In the spruce and bamboo torrefaction test runs, the collected condensates included fractions formed at 20–105, 105–240, and at 240–300 °C. The formation rate of the condensate was measured at 30 min intervals as a function of time and temperature. It was quite similar for both spruce and bamboo, and the results for the bamboo test run are presented in Figure 2. At 20–105 °C, the amount of condensates was very small (about 1 wt %, on wet input basis). At 105–240 °C, the condensates contained a major part of the feedstock moisture and their amounts increased. The maximum amounts were obtained at about 170 °C, when the color of condensates also changed from light yellow into brown. By 240 °C, 12–14 wt % of the original feedstocks had been cumulatively collected as condensates (Table 4).

Figure 2

Figure 2. Formation of the condensate amount, measured at 30 min intervals, as a function of time and temperature inside the reactor in the bamboo test run.

Table 4. Proportions and Mass Yields of Condensates Formed at Different Temperature Ranges in Spruce and Bamboo Torrefaction Test Runs
 20–105 °C105–240 °C240–300 °Ctotal condensate
spruce    
 proportion of total condensate, wt %5.134.660.3100
 mass yield, wt % (on wet input basis)1.510.017.429
bamboo    
 proportion of total condensate, wt %4.338.557.3100
 mass yield, wt % (on wet input basis)1.412.418.432
The main part of total condensates was formed at 240–300 °C. The maximum amount was obtained at 280–300 °C (Figure 2), when visible tar began to form and strong exothermic reactions occurred, which was also corroborated by the gas analyses (Figure 3). The maximum concentrations of carbon dioxide (CO2) and carbon monoxide (CO) were 23 vol % (in nitrogen flow) and 19 vol %, respectively.

Figure 3

Figure 3. CO2 and CO concentrations (% in nitrogen flow) as a function of time and temperature in the torrefaction test run for bamboo.

Formation rate of the condensate as a function of time and temperature in the spruce and bamboo test runs was similar to that in the birch test run.
The mass yields of condensates formed at different temperature levels, torrefied materials and noncondensable gases in the test runs are presented in Figures 46.

Figure 4

Figure 4. Mass yields of condensates formed at different temperature levels, torrefied material, and noncondensable gases in the torrefaction test run of spruce, on wet input basis.

Figure 5

Figure 5. Mass yields of condensates formed at different temperature levels, torrefied material, and noncondensable gases in the torrefaction test run of bamboo, on wet input basis.

Figure 6

Figure 6. Mass yields of condensates formed at different temperature levels, torrefied material, and noncondensable gases in the torrefaction test run of birch, on wet input basis.

Composition of Condensates

The condensates formed at 20–105 °C were very dilute and consisted mostly of water. The spruce and bamboo condensates collected at 240–300 °C had the highest COD, TOC, and TAN values (Table 5). The organic contents of total condensates calculated on the basis of the amounts and analyses of condensate fractions, were quantitatively at the same level as that of the birch condensate (Table 5). The COD/TOC ratios were quite similar (3.4–3.7) for all condensates. The amount of PAHs was only ≤2 mg kg–1 for all condensates.
Table 5. Characteristics of Condensate Fractions and Total Condensate in Spruce and Bamboo Torrefaction Test Runsa
analysiscondensate fraction 105–240 °Ccondensate fraction 240–300 °Ctotal condensateb
spruce   
water content, wt %99.356.473.4
organic matter, wt %0.743.626.6
pH3.02.22.5
COD, g L–137810500
TOC, g L–110240150
COD/TOC3.73.43.3
TAN, mg KOH g–15.512077
bamboo   
water content, wt %97.670.882.4
organic content, wt %2.429.217.6
pH3.23.13.2
COD, g L–156470290
TOC, g L–11614087
COD/TOC3.53.43.3
TAN, mg KOH g–1219563
a

For the birch condensate, pH was 2.5, water content 75 wt %, COD 300 g L–1, TOC 90 g L–1, and TAN 135 mg KOH g–1.

b

Calculated on the basis of amounts and analyses of condensate fractions.

The amounts of organic compounds quantified in total condensates were lower for spruce and bamboo (12–15 wt %) than for birch (19 wt %). This was affected primarily by the differences in the concentration of acetic acid, the main compound, between the condensates (Table 6). In contrast, the amounts of aldehydes, ketones and phenols were higher in the spruce condensate than in the others. The main compounds including acetic acid, 1-hydroxy-2-propanone, methanol, and furfural, and in addition 2-hydroxyacetaldehyde in the spruce condensate comprised, in total, 85–97 wt % of the compounds.
In the condensate fractions of 105–240 °C, the main compounds for spruce and bamboo were acetic acid, methanol, furfural, and 1-hydroxy-2-propanone (Table 7). These compounds are mainly degradation products of hemicelluloses. (16, 17) Acetic acid and methanol comprised 80–90 wt % of the compounds in the fractions.
The organic compounds were concentrated in the condensate fractions formed at 240–300 °C (Table 7), which was due to strong exothermic reactions occurring at 270–290 °C. Cellulose degradation begins to occur already at 255 °C and becomes more significant at 270 °C, whereas lignin begins to decompose to a small extent at 240 °C. (16) The guaiacols, phenols, isoeugenol, and vanillin, the concentrations of which were higher in the spruce condensate, are degradation products of lignin and especially of guaiacyl-type lignin, typical of softwood. (11) The bamboo condensate contained also guaiacol and phenols, but to a lesser extent.
Table 6. Amounts of Water-Soluble Compound Groups in Total Condensatesa in Spruce, Bamboo and Birch Torrefaction Test Runs, wt %
compound groupsprucebamboobirch
total amount14.712.019.1
aldehydes and ketones3.961.332.09
furans0.060.080.01
alcohols1.453.011.46
acids7.626.8015.4
phenols1.650.780.18
a

For spruce and bamboo, calculated on the basis of the amounts and analyses of condensate fractions.

Table 7. Amounts of Water-Soluble Compounds in Condensate Fractions in Spruce and Bamboo Torrefaction Test Runs, wt %
compoundsprucesprucebamboobamboo
temperature level105–240 °C240–300 °C105–240 °C240–300 °C
total amount1.5923.53.4918.6
acetaldehyde0.0110.2000.0320.193
furan0.0040.0350.0050.058
2-propanone (acetone)0.0010.0730.0040.108
methanol0.7121.9820.4604.902
2-butanone0.0020.0530.0070.090
isopropyl alcohol0.0010.0050.0020.012
ethanol0.0000.003 0.005
2-pentanone0.0090.0230.0010.020
n-propanol0.0000.0040.0000.014
1-hydroxy-2-propanone0.0813.3800.1061.345
2-hydroxyacetaldehyde (glycolaldehyde)0.0181.2950.0010.127
1-hydroxy-2-butanone0.0350.0730.0030.100
acetic acid0.52112.1882.7409.840
furfural0.1740.8850.0510.172
2-acetylfuran 0.0630.0010.072
n-propanoic acid0.0010.0020.0010.044
isobutanoic acid0.0000.0330.0010.007
5-methylfurfural 0.0120.0000.006
butanoic acid0.0020.0680.0040.119
pentanoic acid0.0020.0140.0010.010
hexanoic acid0.0000.0310.0000.007
guaiacol0.0070.4050.0120.213
4-methylguaiacol0.0000.2840.0030.052
2-methylphenol, o-cresol0.0000.0090.0010.009
phenol0.0000.0260.0200.222
4-ethylguaiacol0.0010.1150.0030.045
3-methylphenol, m-cresol0.0010.7010.0040.241
2-propylphenol0.0000.0130.0000.006
eugenol0.0000.0540.0010.067
4-ethylphenol0.0010.1540.0090.210
o-vanillin 0.4320.0060.057
syringol, 4-propylphenola0.0000.0580.0010.025
isoeugenol 0.2540.0060.069
4-methylsyringol0.0000.0180.0020.007
5-hydroxy-methylfurfural0.0040.3830.0010.028
catechol 0.180 0.088
4-methylcatechol0.0000.0110.0000.003
4-ethylcatechol 0.014 0.007
a

Syringol in hardwood; 4-propylphenol in softwood.

Utilization Potential of Condensables

The condensates collected in the torrefaction test runs are promising to be utilized for different purposes. The liquid fractions recovered at 105–240 °C for spruce and bamboo were tar-free and PAH-free and contained acetic acid and furfural. They resembled the birch distillate obtained at low temperatures in slow pyrolysis, and consequently have potential to be used as a pesticide, herbicide, fungicide, insecticide, and repellent. (29-32, 36) Acetic acid and furfurals are used as pesticides in plant protection. (37-39) Furfural is also used as a soil fumigant and a wood preservative. (39, 40) Because wood vinegars possess higher effectivity than the separate compounds, (23, 31, 32) the condensate fractions of torrefaction are suggested to be used as such rather than to separate the active compounds from them. At the moment, the effectiveness of individual organic compounds in complex mixtures in use is not known and further investigations on it will be needed.
Because of the low yields and high water contents, the condensates formed at 20–105 °C are not worth a separate utilization. Instead, they can be combined with the fraction of 105–240 °C.
The condensates formed at 240–300 °C contained a high amount of organic matter (30–40 wt %) including also tar, which contains phenolic compounds. Therefore, they may not be suitable for the same purposes as the fractions collected at lower temperatures. Instead, they may have potential as wood preservatives in wood protection. Based on our studies on birch distillates, (29-31) the spruce and bamboo condensates formed at <280 °C might, however, also be utilized similarly as the distillate obtained at ≤240 °C.
The separate compounds, such as acetic acid, furfural, methanol, hydroxyacetaldehyde, guaiacol, phenol, syringol, and catechol, found in the condensates, are among the value-added chemicals from the pyrolysis of lignocellulosic biomass presented recently by de Wild. (41)

Economic Evaluation

Economic evaluation was based on the main mass and energy flows calculated for the base case plant, the saw mill integrate, and the overseas plant without and with the condensate recovery (Table 8). The estimated production costs of the cases are shown in Figure 7. For the base case and the saw mill integrate, the costs were expressed as plant gate values. In the overseas case, shipping costs (3.2 € MWh–1) to Europe were added to the pellet production price. (42) Fixed operating costs consisted of operating labor, maintenance labor, maintenance materials, overheads, insurances, and taxes. Variable operating costs consisted of raw materials, boiler fuels, electricity, and other utilities. Due to the dominant factor in the production price of torrefied pellets, raw material costs were separated out of other variable operating costs. The increased production costs of torrefied pellets were compensated by the extra income from the condensate utilization. The overall benefit was thus decreased production costs for torrefied pellets.
Table 8. Main Mass and Energy Flows of Stand-Alone Torrefaction Plants (Base Case, Overseas Case) and Saw Mill Integrate without and with Condensate Recovery
alternative/utilitybase casebase case condensate recoverysawmill integratesawmill integrate condensate recoveryoverseas caseoverseas case condensate recovery
fuels for pellets, MW5454175175368368
forest fuel, MW5454136136368368
wood chips, MW00393900
torrefied pellet production, MW5656177177382382
torrefied pellet production, t a–172 80072 800231 600231 000500 000500 000
boiler fuels, MW816255055107
forest fuel, MW81602655107
bark, MW00121200
sawdust, MW00141200
purchased electricity, MWe22661212
condensate, t a–1025 000080 0000171 000

Figure 7

Figure 7. Breakdown of torrefied pellets production costs of different cases without and with condensate recovery: condensate price 100 € t–1, condensate profit shared evenly into other costs excluding overseas transport costs.

Wood pellet is the main biomass fuel in large scale pulverized coal boilers as well as at peak and back-up district heating plants. Other type of boilers, for example fluidized bed or grate boilers, use normally cheaper wood fuels, such as wood chips or forestry residues. In the overseas case, the production costs of torrefied pellets were lower than the market price 30 € MWh–1 described by the PIX Index value (FOEX Indexes Ltd.) for industrial wood pellets. In all the torrefaction cases studied, condensate recovery lowered the torrefied pellet production price. Production costs were partly influenced by the production capacity. The savings in inland transport costs in Europe and in storage and use of torrefied pellets at coal power plants compared to wood pellets were not included in the cost values.
The effect of condensate price on the torrefied pellet production price is shown in Table 9. The production costs of torrefied pellets decreased significantly, for example on the order of 5–10 € MWh–1 in medium scale pellet production, when the condensates were recovered for utilization. An average revenue percentage of the whole turnover was estimated to be 15% at a condensate price of 100 € t–1. Then the revenues for condensate recovery were 2.5 M€ in the base case, 8 M€ in the sawmill integrate case, and 17 M€ in the overseas case.
Table 9. Torrefied Pellet Production Price at Different Condensate Price Values in Torrefaction Cases without and with Condensate Recovery
alternativecondensate price, € t–1torrefied pellet price, € MWh–1
base case 43
base case with recovery10040
base case with recovery25032
base case with recovery40024
saw mill integrate 35
saw mill integrate with recovery10031
saw mill integrate with recovery25023
saw mill integrate with recovery40015
overseas case 29
overseas case with recovery10025
overseas case with recovery25017
overseas case with recovery4009

Conclusions

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Mass yields and compositions of torrefaction condensates differed between softwood, hardwood, and herbaceous feedstocks and temperature ranges. The total condensates formed at ≤280 °C will be promising to be utilized, for example, as biodegradable pesticides to replace synthetic ones. Higher temperatures are critical, because at about 290 °C strong exothermic reactions will occur, which considerably decreases the yield of torrefied material and produces tar containing condensates. The results were in accordance with those obtained by us previously (29, 30) for birch feedstock in larger-scale slow pyrolysis retorts.
The quality and utilization potential of condensates can be affected by temperature ranges. Specific temperature ranges can be chosen, when the aim is to for example maximize the yield of some components like acetic acid. Separation of compounds from the mixture is, however, a challenging task and possibly not an economic way to utilize the condensates.
Utilization of torrefaction condensates from several wood materials for different purposes will be further studied with different tests within the Horizon 2020 EU project “Mobile and flexible industrial processing of biomass“ (Mobile Flip).
On the basis of the economic assessment carried out for three different torrefaction cases including the base case plant, the saw mill integrate, and the overseas plant without and with the condensate recovery, it is possible to produce, in addition to torrefied material, valuable liquids. The production costs of torrefied pellets can be lowered significantly by recovering and selling the condensates to new applications. The biopesticide markets are, however, still undeveloped. This is due to different regulations, which are the main barriers to future applications.

Author Information

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  • Corresponding Author
  • Authors
    • Eeva Kuoppala - VTT Technical Research Centre of Finland Ltd., P.O. Box 1000, 02044 VTT, Espoo, Finland
    • Vesa Arpiainen - VTT Technical Research Centre of Finland Ltd., P.O. Box 1000, 02044 VTT, Espoo, Finland
  • Notes
    The authors declare no competing financial interest.

Acknowledgment

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The authors are grateful to the anonymous reviewers for their constructive comments to the manuscript. The EC 7th FP project “Production of solid sustainable energy carriers from biomass by means of torrefaction (SECTOR)” and VTT Technical Research Centre of Finland Ltd. are acknowledged for funding. Michiel Carbo from Energy research Centre of the Netherlands (ECN) is thanked for delivering the spruce and bamboo samples for torrefaction test runs. At VTT, thanks are especially due to Carl Wilén.

References

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This article references 42 other publications.

  1. 1
    van der Stelt, M. J. C.; Gerhauser, H.; Kiel, J. H. A.; Ptasinski, K. J. Biomass upgrading by torrefaction for the production of biofuels: A review Biomass Bioenergy 2011, 35, 3748 3762
  2. 2
    Li, J.; Brzdekiewicz, A.; Yang, W.; Blasiak, W. Co-firing based on biomass torrefaction in a pulverized coal boiler with aim of 100% fuel switching Appl. Energy 2012, 99, 344 354
  3. 3
    Peng, J. H.; Bi, H. T.; Lim, C. J.; Sokhansanj, S. Study on density, hardness, and moisture uptake of torrefied wood pellets Energy Fuels 2013, 27, 967 974
  4. 4
    Repellin, V.; Govin, A.; Rolland, M.; Guyonnet, R. Energy requirement for fine grinding of torrefied wood Biomass Bioenergy 2010, 34, 923 930
  5. 5
    Tumuluru, J. S.; Hess, J. R.; Boardman, R. D.; Wright, C. T.; Westover, T. L. Formulation, pretreatment, and densification options to improve biomass specifications for co-firing high percentages with coal Ind. Biotechnol. 2012, 8, 113 132
  6. 6
    Järvinen, T.; Agar, D. Experimentally determined storage and handling properties of fuel pellets made from torrefied whole-tree pine chips, logging residues and beech stem wood Fuel 2014, 129, 330 339
  7. 7
    Batidzirai, B.; Mignot, A. P. R.; Schakel, W. B.; Junginger, H. M.; Faaij, A. P. C. Biomass torrefaction technology: Techno-economic status and future prospects Energy 2013, 62, 196 214
  8. 8
    Wilén, C.; Jukola, P.; Järvinen, T.; Sipilä, K.; Verhoeff, F.; Kiel, J. Wood Torrefaction – Pilot Tests and Utilisation Prospects; VTT Technology 122, VTT Technical Research Centre of Finland: Espoo, Finland, 2013.
  9. 9
    Prins, M. J.; Ptasinski, K. J.; Janssen, F. J. J. G. Torrefaction of wood, Part 1. Weight loss kinetics J. Anal. Appl. Pyrolysis 2006, 77, 28 34
  10. 10
    Prins, M. J.; Ptasinski, K. J.; Janssen, F. J. J. G. Torrefaction of wood, Part 2. Analysis of products J. Anal. Appl. Pyrolysis 2006, 77, 35 40
  11. 11
    Alén, R. Structure and chemical composition of wood. In Forest Products Chemistry; Stenius, P., Ed.; Fapet Oy: Helsinki, Finland, 2000; pp 11 57.
  12. 12
    Scurlock, J. M. O.; Dayton, D. C.; Hames, B. Bamboo: An overlooked biomass resource? Biomass Bioenergy 2000, 19, 229 244
  13. 13
    Li, X. B.; Shupe, T. F.; Peter, G. F.; Hse, C. Y.; Eberhardt, T. L. Chemical changes with maturation of the bamboo species Phyllostachys pubescens J. Tropical Forest Sci. 2007, 19 (1) 6 12
  14. 14
    Alén, R.; Kuoppala, E.; Oesch, P. Formation of the main degradation compound groups from wood and its components during pyrolysis J. Anal. Appl. Pyrolysis 1996, 36, 137 148
  15. 15
    Kotilainen, R.Chemical changes in wood during heating at 150–260 °C. Ph.D. Thesis. Research Report No. 80; Department of Chemistry, University of Jyväskylä, Jyväskyla, Finland, 2000.
  16. 16
    Shoulaifar, T. K.; DeMartini, N.; Willför, S.; Pranovich, A.; Smeds, A. I.; Virtanen, T. A. P.; Maunu, S.-L.; Verhoeff, F.; Kiel, J. H. A.; Hupa, M. Impact of torrefaction on the chemical structure of birch wood Energy Fuels 2014, 28, 3863 3872
  17. 17
    Branca, C.; Di Blasi, C.; Galgano, A.; Brorström, M. Effects of the torrefaction conditions on the fixed-bed pyrolysis of Norway spruce Energy Fuels 2014, 28, 5882 5891
  18. 18
    Tiilikkala, K.; Fagernäs, L.; Tiilikkala, J. History and use of wood pyrolysis liquids as biocide and plant protection product Open Agric. J. 2010, 4, 111 118
  19. 19
    Mu, J.; Yu, Z.; Wu, W.; Wu, Q. Preliminary study of application effect of bamboo vinegar on vegetable growth Forest Stud. Chin. 2006, 8, 43 47
  20. 20
    Mu, J.; Uehara, T.; Furuno, T. Effect of bamboo vinegar on regulation of germination and radicle growth of seed plants J. Wood Sci. 2003, 49, 262 270
  21. 21
    Mu, J.; Uehara, T.; Furuno, T. Effect of bamboo vinegar on regulation of germination and radicle growth of seed plants II: composition of moso bamboo vinegar at different collection temperature and its effects J. Wood Sci. 2004, 50, 470 476
  22. 22
    Jung, K. H. Growth inhibition effect of pyroligneous acid on pathogenic fungus, Alternaria mali, the agent of Alternaria blotch of apple Biotechnol. Bioprocess Eng. 2007, 12, 318 322
  23. 23
    Baimark, Y.; Niamsaa, N. Study on wood vinegars for use as coagulating and antifungal agents on the production of natural rubber sheet Biomass Bioenergy 2009, 33, 994 998
  24. 24
    Velmurugan, N.; Chun, S. S.; Han, S. S.; Lee, Y. S. Characterization of chikusaku-eki and mokusaku-eki and its inhibitory effect on sapstaining fungal growth in laboratory scale Int. J. Environ. Sci. Technol. 2009, 6, 13 22
  25. 25
    Inoue, S.; Imamura, Y.; Meier, D. Components and anti-fungal efficiency of wood-vinegar-liquor prepared under different carbonization conditions Wood Res. 2000, 87, 34 36
  26. 26
    Orihashi, K.; Kojima, Y.; Terazawa, M. Deterrent effect of rosin and wood tar against barking by the gray-sided vole (Clethrionomys rufocanus bedfordiae) J. Forest Res. 2001, 6, 191 196
  27. 27
    Lindqvist, I.; Lindqvist, B.; Tiilikkala, K.; Hagner, M.; Penttinen, O. P.; Pasanen, T.; Setälä, H. Birch tar oil is an effective mollusc repellent: Field and laboratory experiments using Arianta arbustorum (Gastroboda: Helicidae) and Arion lusitanicus (Gastroboda: Arionidae) Agric. Food Sci. 2010, 19, 1 12
  28. 28
    Hagner, M.; Pasanen, T.; Lindqvist, B.; Lindqvist, I.; Tiilikkala, K.; Penttinen, O. P.; Setälä, H. Effects of birch tar oils on soil organisms and plants Agric. Food Sci. 2010, 19, 13 23
  29. 29
    Fagernäs, L.; Kuoppala, E.; Tiilikkala, K.; Oasmaa, A. Chemical composition of birch wood slow pyrolysis products Energy Fuels 2012, 26, 1275 1283
  30. 30
    Fagernäs, L.; Kuoppala, E.; Simell, P. Polycyclic aromatic hydrocarbons in birch wood slow pyrolysis products Energy Fuels 2012, 26, 6960 6970
  31. 31
    Fagernäs, L.; Kuoppala, E.; Arpiainen, V.; Tiilikkala, K.; Lindqvist, I.; Lindqvist, B.; Järvinen, O.; Hagner, M.; Setälä, H.; Bergroth, K. Development of Slow Pyrolysis Business Operations in Finland; VTT Technology 59, VTT Technical Research Centre of Finland: Espoo, Finland, 2012, (In Finnish, English abstract).
  32. 32
    Hagner, M.; Kuoppala, E.; Fagernäs, L.; Tiilikkala, K.; Setälä, H. Using the copse snail Arianta arbustorum (Linnaeus) to detect repellent compounds and the quality of wood vinegar Int. J. Environ. Res. 2015, 9, 53 60
  33. 33
    Fagernäs, L.; Brammer, J.; Wilén, C.; Lauer, M.; Verhoeff, F. Drying of biomass for second generation synfuel production Biomass Bioenergy 2010, 34, 1267 1277
  34. 34
    Arpiainen, V.; Fagernäs, L.; de Wild, P.; Carbo, M.Report on Optimization Potential Towards (Co-)production of Chemicals and Materials. Production of Solid Sustainable Energy Carriers from Biomass by Means of Torrefaction (SECTOR); Deliverable No. 3.6; VTT Technical Research Centre of Finland: Espoo, Finland, 2014.
  35. 35
    Daza Montaňo, C. M.; Pels, J. R.; Fryda, L. E.; Zwart, R. W. R. Evaluation of torrefied bamboo for sustainable bioenergy production. In Proceedings of the IXth World Bamboo Congress, Antwerp/Merksplas, Belgium, April 2012; pp 809 818.
  36. 36
    Hagner, M.Potential of the Slow Pyrolysis Products Birch Tar Oil, Wood Vinegar and Biochar in Sustainable Plant Protection – Pesticidal Effects, Soil Improvement and Environmental Risks; Reports from the Department of Environmental Sciences No. 20; University of Helsinki: Lahti, Finland, 2013.
  37. 37
    Malkomes, H. P. Einfluss hoher, zur Unkrautbekämpfung notwendiger Dosierungen eines Essigsäure-Herbizids auf Mikroorganismen und microbielle Aktivitäten im boden Z. Pflanzenkrankh. Pflanzenschutz 2005, 112, 457 471
  38. 38
    Ntalli, N.; Vargiu, S.; Menkissoglu-Spiroudi, U.; Caboni, P. Nematicidal carboxylic acids and aldehydes from Melia azedarach fruits J. Agric. Food Chem. 2010, 58, 11390 11394
  39. 39
    Liu, W. W.; Zhao, L. J.; Wang, C.; Mu, W.; Liu, F. Bioactive evaluation and application of antifungal volatiles generated by five soil bacteria Acta Phytophylacica Sin. 2009, 36, 97 105
  40. 40
    Lande, S.; Westin, M.; Schneider, M. H. Eco-efficient wood protection. Furfurylated wood as alternative to traditional wood preservation Manage. Environ. Qual. Int. J. 2004, 15, 529 540
  41. 41
    de Wild, P.; Reith, H.; Heeres, E. Biomass pyrolysis for chemicals Biofuels 2012, 2, 185 208
  42. 42
    Koppejan, J.; Sokhansanj, S.; Melin, S.; Madrali, S.Status Overview of Torrefaction Technologies; IEA Bioenergy Task 32, Report; IEA Bioenergy: Enschede, The Netherlands, 2012.

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  • Figure 1

    Figure 1. Slow pyrolysis testing facility. 1: Electric oven. 2: Reactor. 3: Cooling section.

    Figure 2

    Figure 2. Formation of the condensate amount, measured at 30 min intervals, as a function of time and temperature inside the reactor in the bamboo test run.

    Figure 3

    Figure 3. CO2 and CO concentrations (% in nitrogen flow) as a function of time and temperature in the torrefaction test run for bamboo.

    Figure 4

    Figure 4. Mass yields of condensates formed at different temperature levels, torrefied material, and noncondensable gases in the torrefaction test run of spruce, on wet input basis.

    Figure 5

    Figure 5. Mass yields of condensates formed at different temperature levels, torrefied material, and noncondensable gases in the torrefaction test run of bamboo, on wet input basis.

    Figure 6

    Figure 6. Mass yields of condensates formed at different temperature levels, torrefied material, and noncondensable gases in the torrefaction test run of birch, on wet input basis.

    Figure 7

    Figure 7. Breakdown of torrefied pellets production costs of different cases without and with condensate recovery: condensate price 100 € t–1, condensate profit shared evenly into other costs excluding overseas transport costs.

  • References

    ARTICLE SECTIONS
    Jump To

    This article references 42 other publications.

    1. 1
      van der Stelt, M. J. C.; Gerhauser, H.; Kiel, J. H. A.; Ptasinski, K. J. Biomass upgrading by torrefaction for the production of biofuels: A review Biomass Bioenergy 2011, 35, 3748 3762
    2. 2
      Li, J.; Brzdekiewicz, A.; Yang, W.; Blasiak, W. Co-firing based on biomass torrefaction in a pulverized coal boiler with aim of 100% fuel switching Appl. Energy 2012, 99, 344 354
    3. 3
      Peng, J. H.; Bi, H. T.; Lim, C. J.; Sokhansanj, S. Study on density, hardness, and moisture uptake of torrefied wood pellets Energy Fuels 2013, 27, 967 974
    4. 4
      Repellin, V.; Govin, A.; Rolland, M.; Guyonnet, R. Energy requirement for fine grinding of torrefied wood Biomass Bioenergy 2010, 34, 923 930
    5. 5
      Tumuluru, J. S.; Hess, J. R.; Boardman, R. D.; Wright, C. T.; Westover, T. L. Formulation, pretreatment, and densification options to improve biomass specifications for co-firing high percentages with coal Ind. Biotechnol. 2012, 8, 113 132
    6. 6
      Järvinen, T.; Agar, D. Experimentally determined storage and handling properties of fuel pellets made from torrefied whole-tree pine chips, logging residues and beech stem wood Fuel 2014, 129, 330 339
    7. 7
      Batidzirai, B.; Mignot, A. P. R.; Schakel, W. B.; Junginger, H. M.; Faaij, A. P. C. Biomass torrefaction technology: Techno-economic status and future prospects Energy 2013, 62, 196 214
    8. 8
      Wilén, C.; Jukola, P.; Järvinen, T.; Sipilä, K.; Verhoeff, F.; Kiel, J. Wood Torrefaction – Pilot Tests and Utilisation Prospects; VTT Technology 122, VTT Technical Research Centre of Finland: Espoo, Finland, 2013.
    9. 9
      Prins, M. J.; Ptasinski, K. J.; Janssen, F. J. J. G. Torrefaction of wood, Part 1. Weight loss kinetics J. Anal. Appl. Pyrolysis 2006, 77, 28 34
    10. 10
      Prins, M. J.; Ptasinski, K. J.; Janssen, F. J. J. G. Torrefaction of wood, Part 2. Analysis of products J. Anal. Appl. Pyrolysis 2006, 77, 35 40
    11. 11
      Alén, R. Structure and chemical composition of wood. In Forest Products Chemistry; Stenius, P., Ed.; Fapet Oy: Helsinki, Finland, 2000; pp 11 57.
    12. 12
      Scurlock, J. M. O.; Dayton, D. C.; Hames, B. Bamboo: An overlooked biomass resource? Biomass Bioenergy 2000, 19, 229 244
    13. 13
      Li, X. B.; Shupe, T. F.; Peter, G. F.; Hse, C. Y.; Eberhardt, T. L. Chemical changes with maturation of the bamboo species Phyllostachys pubescens J. Tropical Forest Sci. 2007, 19 (1) 6 12
    14. 14
      Alén, R.; Kuoppala, E.; Oesch, P. Formation of the main degradation compound groups from wood and its components during pyrolysis J. Anal. Appl. Pyrolysis 1996, 36, 137 148
    15. 15
      Kotilainen, R.Chemical changes in wood during heating at 150–260 °C. Ph.D. Thesis. Research Report No. 80; Department of Chemistry, University of Jyväskylä, Jyväskyla, Finland, 2000.
    16. 16
      Shoulaifar, T. K.; DeMartini, N.; Willför, S.; Pranovich, A.; Smeds, A. I.; Virtanen, T. A. P.; Maunu, S.-L.; Verhoeff, F.; Kiel, J. H. A.; Hupa, M. Impact of torrefaction on the chemical structure of birch wood Energy Fuels 2014, 28, 3863 3872
    17. 17
      Branca, C.; Di Blasi, C.; Galgano, A.; Brorström, M. Effects of the torrefaction conditions on the fixed-bed pyrolysis of Norway spruce Energy Fuels 2014, 28, 5882 5891
    18. 18
      Tiilikkala, K.; Fagernäs, L.; Tiilikkala, J. History and use of wood pyrolysis liquids as biocide and plant protection product Open Agric. J. 2010, 4, 111 118
    19. 19
      Mu, J.; Yu, Z.; Wu, W.; Wu, Q. Preliminary study of application effect of bamboo vinegar on vegetable growth Forest Stud. Chin. 2006, 8, 43 47
    20. 20
      Mu, J.; Uehara, T.; Furuno, T. Effect of bamboo vinegar on regulation of germination and radicle growth of seed plants J. Wood Sci. 2003, 49, 262 270
    21. 21
      Mu, J.; Uehara, T.; Furuno, T. Effect of bamboo vinegar on regulation of germination and radicle growth of seed plants II: composition of moso bamboo vinegar at different collection temperature and its effects J. Wood Sci. 2004, 50, 470 476
    22. 22
      Jung, K. H. Growth inhibition effect of pyroligneous acid on pathogenic fungus, Alternaria mali, the agent of Alternaria blotch of apple Biotechnol. Bioprocess Eng. 2007, 12, 318 322
    23. 23
      Baimark, Y.; Niamsaa, N. Study on wood vinegars for use as coagulating and antifungal agents on the production of natural rubber sheet Biomass Bioenergy 2009, 33, 994 998
    24. 24
      Velmurugan, N.; Chun, S. S.; Han, S. S.; Lee, Y. S. Characterization of chikusaku-eki and mokusaku-eki and its inhibitory effect on sapstaining fungal growth in laboratory scale Int. J. Environ. Sci. Technol. 2009, 6, 13 22
    25. 25
      Inoue, S.; Imamura, Y.; Meier, D. Components and anti-fungal efficiency of wood-vinegar-liquor prepared under different carbonization conditions Wood Res. 2000, 87, 34 36
    26. 26
      Orihashi, K.; Kojima, Y.; Terazawa, M. Deterrent effect of rosin and wood tar against barking by the gray-sided vole (Clethrionomys rufocanus bedfordiae) J. Forest Res. 2001, 6, 191 196
    27. 27
      Lindqvist, I.; Lindqvist, B.; Tiilikkala, K.; Hagner, M.; Penttinen, O. P.; Pasanen, T.; Setälä, H. Birch tar oil is an effective mollusc repellent: Field and laboratory experiments using Arianta arbustorum (Gastroboda: Helicidae) and Arion lusitanicus (Gastroboda: Arionidae) Agric. Food Sci. 2010, 19, 1 12
    28. 28
      Hagner, M.; Pasanen, T.; Lindqvist, B.; Lindqvist, I.; Tiilikkala, K.; Penttinen, O. P.; Setälä, H. Effects of birch tar oils on soil organisms and plants Agric. Food Sci. 2010, 19, 13 23
    29. 29
      Fagernäs, L.; Kuoppala, E.; Tiilikkala, K.; Oasmaa, A. Chemical composition of birch wood slow pyrolysis products Energy Fuels 2012, 26, 1275 1283
    30. 30
      Fagernäs, L.; Kuoppala, E.; Simell, P. Polycyclic aromatic hydrocarbons in birch wood slow pyrolysis products Energy Fuels 2012, 26, 6960 6970
    31. 31
      Fagernäs, L.; Kuoppala, E.; Arpiainen, V.; Tiilikkala, K.; Lindqvist, I.; Lindqvist, B.; Järvinen, O.; Hagner, M.; Setälä, H.; Bergroth, K. Development of Slow Pyrolysis Business Operations in Finland; VTT Technology 59, VTT Technical Research Centre of Finland: Espoo, Finland, 2012, (In Finnish, English abstract).
    32. 32
      Hagner, M.; Kuoppala, E.; Fagernäs, L.; Tiilikkala, K.; Setälä, H. Using the copse snail Arianta arbustorum (Linnaeus) to detect repellent compounds and the quality of wood vinegar Int. J. Environ. Res. 2015, 9, 53 60
    33. 33
      Fagernäs, L.; Brammer, J.; Wilén, C.; Lauer, M.; Verhoeff, F. Drying of biomass for second generation synfuel production Biomass Bioenergy 2010, 34, 1267 1277
    34. 34
      Arpiainen, V.; Fagernäs, L.; de Wild, P.; Carbo, M.Report on Optimization Potential Towards (Co-)production of Chemicals and Materials. Production of Solid Sustainable Energy Carriers from Biomass by Means of Torrefaction (SECTOR); Deliverable No. 3.6; VTT Technical Research Centre of Finland: Espoo, Finland, 2014.
    35. 35
      Daza Montaňo, C. M.; Pels, J. R.; Fryda, L. E.; Zwart, R. W. R. Evaluation of torrefied bamboo for sustainable bioenergy production. In Proceedings of the IXth World Bamboo Congress, Antwerp/Merksplas, Belgium, April 2012; pp 809 818.
    36. 36
      Hagner, M.Potential of the Slow Pyrolysis Products Birch Tar Oil, Wood Vinegar and Biochar in Sustainable Plant Protection – Pesticidal Effects, Soil Improvement and Environmental Risks; Reports from the Department of Environmental Sciences No. 20; University of Helsinki: Lahti, Finland, 2013.
    37. 37
      Malkomes, H. P. Einfluss hoher, zur Unkrautbekämpfung notwendiger Dosierungen eines Essigsäure-Herbizids auf Mikroorganismen und microbielle Aktivitäten im boden Z. Pflanzenkrankh. Pflanzenschutz 2005, 112, 457 471
    38. 38
      Ntalli, N.; Vargiu, S.; Menkissoglu-Spiroudi, U.; Caboni, P. Nematicidal carboxylic acids and aldehydes from Melia azedarach fruits J. Agric. Food Chem. 2010, 58, 11390 11394
    39. 39
      Liu, W. W.; Zhao, L. J.; Wang, C.; Mu, W.; Liu, F. Bioactive evaluation and application of antifungal volatiles generated by five soil bacteria Acta Phytophylacica Sin. 2009, 36, 97 105
    40. 40
      Lande, S.; Westin, M.; Schneider, M. H. Eco-efficient wood protection. Furfurylated wood as alternative to traditional wood preservation Manage. Environ. Qual. Int. J. 2004, 15, 529 540
    41. 41
      de Wild, P.; Reith, H.; Heeres, E. Biomass pyrolysis for chemicals Biofuels 2012, 2, 185 208
    42. 42
      Koppejan, J.; Sokhansanj, S.; Melin, S.; Madrali, S.Status Overview of Torrefaction Technologies; IEA Bioenergy Task 32, Report; IEA Bioenergy: Enschede, The Netherlands, 2012.

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