
About the Cover:
Green synthesis of MIL-100 framework material is accomplished by a facile mechanical grinding process (left, represented by mortar and pestle) free from any toxic solvents. Also shown is the use of a water-based reconstruction to enable encapsulation of drug molecules into MIL-100 pores (right, represented by vial). (See B. E. Souza, A. F. Möslein, K. Titov, J. D. Taylor, S. Rudić, and J.-C. Tan; DOI: 10.1021/acssuschemeng.0c01471.)
View the article.Perspectives

Characterizing Variability in Lignocellulosic Biomass: A Review
Jipeng Yan - ,
Oluwafemi Oyedeji - ,
Juan H. Leal - ,
Bryon S. Donohoe - ,
Troy A. Semelsberger - ,
Chenlin Li - ,
Amber N. Hoover - ,
Erin Webb - ,
Elizabeth A. Bose - ,
Yining Zeng - ,
C. Luke Williams - ,
Kastli D. Schaller - ,
Ning Sun - ,
Allison E. Ray *- , and
Deepti Tanjore *
Feedstock variability is a significant barrier to the scale-up and commercialization of lignocellulosic biofuel technologies. Variability in feedstock characteristics and behavior creates numerous challenges to the biorefining industry by affecting continuous operation and biofuels yields. Currently, feedstock variability is understood and explained largely on the basis of chemical composition. Physical and mechanical properties and behavior of lignocellulosic feedstock in various unit operations, studied through advanced analytical methods, can further explain variability. Such studies will enable us in developing processes and designing equipment to improve operation and conversion performance. In this perspective, we review several advanced analytical methods that measure density, moisture content, thermal properties, flowability, grindability, rheology properties, and micromorphological characteristics. We also discuss the correlations and interactions among these properties that reflect the complexity of lignocellulosic biomass as a feedstock and the associated quality metrics and logistics of supplying consistent quality feedstock to a biorefinery. We also examine methods that have not traditionally been used to characterize lignocellulosic feedstocks but have the potential to bridge the gap in our explanation of feedstock variability.
Features

Perspective on Technical Lignin Fractionation
Hasan Sadeghifar *- and
Arthur Ragauskas *
Technical lignin extracted from pulping and biorefining processes provides a class of complex and polydisperse phenolic polymers. Preparation of lignin with lower structural complexity and polydispersity through lignin fractionation is one of the primary solutions to engineer lignin into a value-added material. Sequential lignin fraction by pH controlled precipitation from 12 to 1 is one of the primary developed methods. Partial solubility of lignin in organic solvents is another promising method for lignin fractionation. Organic solvents with different polarity and solubility factors are able to fractionate lignin, yielding a more homogeneous chemical structure. As a modification of the lignin fractionation process using solvents, water/organic solvents mixture, such as propan-2-one, alcohols, and acetic acid, from room to high temperature has been proposed as a greener method for lignin fractionation. Using membrane technology is another promising method and current results indicate a good potential for lignin recovery and fractionation.
Letters

Reticulation of 2D Semiconductors by Metal–Organic Approach for Efficient Hydrogen Evolution
Hongmei Dai - ,
Jiao Sun - ,
Yi Zhou - ,
Zirui Zhou - ,
Wei Luo *- ,
Guangfeng Wei *- , and
Hexiang Deng *
We report a universal approach to synthesize a series of three-dimensional (3D) metal–organic constructs by linking 2D metal dichalcogenides with organic amine molecules [p-phenylenediamine (PPDA), biphenyl diamine (BPDA), tetra(4-aminophenyl) methane) (TPMA)]. Accurate interlayer distances, ranging from 0.61 to 1.7 nm, are dialed-in by the organic components in 3D constructs of MoS2, MoSe2, and WS2. This allows for the exploitation of space between inorganic layers and internal active sites, as reflected in the reduction of band gap, from 2.05 eV in pristine MoS2 to 0.85 eV in a TPMA-MoS2 construct, and an increase in electrical conductivity by 3 × 103 times. Density functional theory calculation further confirms that the promotions in physical properties originate in the formation of 3D constructs. Electrodes based on TPMA-MoS2 offer an overpotential of 103.1 mV at 10 mA cm–2 in hydrogen evolution reactions, standing as the best molecule-based electrodes, with negligible decay in performance during a 12,000-cycle test.
Articles

Detailed Investigation of Compatibility of Hydrothermal Liquefaction Derived Biocrude Oil with Fossil Fuel for Corefining to Drop-in Biofuels through Structural and Compositional Analysis
Kamaldeep Sharma - ,
Thomas Helmer Pedersen - ,
Saqib Sohail Toor - ,
Yves Schuurman - , and
Lasse Aistrup Rosendahl *
Large-scale commercialization of drop-in biofuel technologies requires a deeper understanding of the molecular structure of biocrude oils and their compatibility with fossil crudes in terms of molecular interactions that govern miscibility. For the first time, the compatibility of hydrothermal liquefaction (HTL) derived biocrude obtained from pinewood with straight-run gas oil (SRGO) was comprehensively investigated by theoretical prediction using Hansen double sphere plots and experimental confirmation from miscibility studies to achieve a biofeed compatible for coprocessing at refineries. The Hansen solubility parameters (HSPs) for biocrude, biocrude components (residue and light and heavy distillate fractions), and SRGO were determined by plotting a three-dimensional Hansen solubility sphere plot based on the experimental solubility data obtained on their solubility studies in 38 different solvents. The compatibility of HTL biocrude oil with SRGO was verified from the solubility distance (Ra) and relative energy difference (RED) values obtained from the center of their Hansen spheres and difference in HSPs, respectively, in a Hansen double sphere solubility plot. The experimental data obtained on miscibility studies confirmed that pyridine, cyclohexanone, and a pyridine–cyclohexanone solvent mixture (1:1) occupy a well-defined Hansen space and show fitting to HSPs of the biocrude–SRGO blend, improve the overall compatibility of the blending mixture, and display a maximum miscibility of 72%. To correlate the compatibility with the molecular structure, the compatibility of light, heavy, and residual fractions obtained by fractional distillation of HTL biocrude (pinewood) was also evaluated with SRGO using the Hansen double sphere plot, and a close agreement with differential scanning calorimetry (DSC) results as well as the experimental data on miscibility studies was verified. Furthermore, the comprehensive estimation of the detailed composition and chemical nature of biocrude and light, heavy, and residual fractions by the means of elemental (CHN/O), GC-MS, and GC × GC analysis was also presented. Additionally, the correlation between compatibility and interactions within chemical functionalities of blend components was established by analyzing the contribution of aromatic, aliphatic, and oxygen containing functional groups to the miscibility using quantitative 13C NMR spectroscopy. The present study reports a mixing strategy to assess the compatibility of biocrudes, heavy distillate fractions, asphaltenes, residues, and polymers with existing petroleum infrastructure for the cost-effective biorefinery process to balance economic and environmental considerations.

The Future is Garbage: Repurposing of Food Waste to an Integrated Biorefinery
Elvis Ebikade - ,
Abhay Athaley - ,
Benjamin Fisher - ,
Kai Yang - ,
Changqing Wu - ,
Marianthi G. Ierapetritou - , and
Dionisios G. Vlachos *
Globally, 1.3 billion tons of food is wasted annually, with few uses other than landfilling, anaerobic digestion, or composting. Food waste (FW) repurposing provides an alternative waste management strategy toward meeting goal 12 of the United Nations sustainable development goals. Here, we present an integrated biorefinery technology, repurposing potato peel waste (PPW) for manufacturing multiple biobased value-added products. We report an integrated biorefinery comprising three stepwise processes: ultrasonic extraction to recover extractives for high activity antioxidants’ production, optimized hydrolysis and dehydration of glucose resulting in the highest reported yields (54%) of 5-hydroxymethylfurfural (HMF), directly from potato peels, for manufacturing biobased chemical precursors, and finally, pyrolysis of the residual lignin into biochar for remediating pesticide contaminated water, improving water quality. As a best-case scenario, we obtain revenues of about $6300 per MT of dry PPW. This provides the opportunity for successful translation of our technology to an economically profitable process using zero value food waste. This study provides a sustainable valorization blueprint that can be extended to other types of FW for improving the economics of biomass-based biorefineries by manufacturing multiple renewable products.

Enhanced Lipid Accumulation through a Regulated Metabolic Pathway of Phosphorus Luxury Uptake in the Microalga Chlorella vulgaris under Nitrogen Starvation and Phosphorus Repletion
Feifei Chu - ,
Jun Cheng *- ,
Ke Li - ,
Yangang Wang - ,
Xi Li - , and
Weijuan Yang
To determine the underlying causes of increased lipid productivity in Chlorella vulgaris, cells were grown in nitrogen-starved phosphorus-replete (N–P+) conditions, and oxidative phosphorylation pathways, luxury phosphorus uptake, photosynthetic characteristics, and lipid productivity were investigated. A maximum lipid productivity of 82.0 mg L–1 day–1 was obtained under N–P+ conditions, which was 4.6-fold and 1.5-fold higher than that obtained under nitrogen and phosphorus-replete and N-Plim conditions, respectively. Genes involved in oxidative phosphorylation, including ATP synthase (fold change = 38.74), ATP phosphohydrolase (fold change = 18.19), inorganic pyrophosphatase (fold change = 25.94), and NADH dehydrogenase, were primarily upregulated in N–P+ conditions. The ATP and total ATPase contents in cells were greater under N–P+ conditions than under control conditions, which suggests there may be a greater energy supply for lipid biosynthesis under N–P+ conditions. 31P NMR spectra results indicate that phosphorus was luxuriously assimilated by cells under N–P+ conditions and was mainly stored as pyrophosphate, polyphosphate, orthophosphate, and monoesters. The maximum quantum efficiency and relative electron transport rate of C. vulgaris cultivated under N–P+ conditions were 0.55 and 23, respectively, which were greater than under nitrogen-starved phosphorus-limited (N-Plim) conditions. Nitrogen starvation and phosphorus repletion is undoubtedly an optimal strategy for lipid accumulation.

CO2-Promoted Hydration of Propargylic Alcohols: Green Synthesis of α-Hydroxy Ketones by an Efficient and Recyclable AgOAc/Ionic Liquid System
Di Li - ,
Yanyan Gong - ,
Minchen Du - ,
Chao Bu - ,
Cheng Chen - ,
Somboon Chaemcheun - ,
Jia Hu - ,
Yongxing Zhang - ,
Ye Yuan *- , and
Francis Verpoort *
α-Hydroxy ketones are a series of biologically active fragments in nature as well as important synthons for organic chemistry. Herein, an AgOAc/1-ethyl-3-methylimidazolium acetate ionic liquid system was developed for the CO2-promoted hydration of propargylic alcohols and H2O to produce α-hydroxy ketones. Diverse desired products could be obtained in satisfactory yields under 1 bar of CO2 pressure with the catalysis of only a trace amount of silver (0.005–0.25 mol %), which is the lowest level ever reported for the metal-catalyzed systems. In particular, this system had robust recyclability, and it could be reused effectively at least 5 times. Furthermore, an unprecedented turnover number (TON) of 9200 was achieved, which is considered to be the highest TON ever reached for this hydration.

Eco-Friendly Facile Three-Step Recycling Method of (Nd-RE)2Fe14B Magnet Sludge and Enhancement of (BH)max by Ball Milling in Ethanol
Syed Kamran Haider - ,
Jin-Young Lee - ,
Dongsoo Kim *- , and
Young Soo Kang *
A new recycling method of (Nd-RE)2Fe14B (RE = Pr, Nd, Tb, Dy) magnet sludge has been reported in this work. (Nd-RE)2Fe14B sludge obtained during the cutting and grinding process of the (Nd-RE)2Fe14B magnet was dissolved in H2SO4 by leaching and then annealed at 1000 °C to obtain the oxides of RE and Fe. Boric acid and CaH2 were added to these oxides, and the mixture was pelletized. Then, a reduction–diffusion (R-D) reaction was carried out at 1000 °C under Ar gas. After removal of CaO (byproduct of R-D reaction) by washing with water, (Nd-RE)2Fe14B powder showed a (BH)max value around 6.6 MGOe. In order to remove CaO particles completely, ball milling was done in ethanol which removed CaO particles seven times more efficiently as compared to the washing with water. Efficient removal of CaO and crystallite modification after ball milling increased the (BH) max value of the recycled (Nd-RE)2Fe14B powder up to higher than 10 MGOe. In this method, any harmful reagent did not contaminate the environment as compared to the previously used physical methods where CO2, SO2, NOX, CH4, and bromo trifluoro-Halon 1301 are produced and left to the environment. SO2 and SO3 produced during the annealing step were dissolved in the water immediately.

Selective Enzymatic Release and Gel Formation by Cross-Linking of Feruloylated Glucurono-Arabinoxylan from Corn Bran
Line Munk - ,
Jan Muschiol - ,
Kai Li - ,
Ming Liu - ,
Alixander Perzon - ,
Sebastian Meier - ,
Peter Ulvskov - , and
Anne S. Meyer *
Corn bran is a major agro-industrial byproduct from corn starch processing. The bran is particularly rich in highly substituted feruloylated glucuronoarabinoxylan (FGAX). Yet, due to its recalcitrance to biocatalytic degradation, corn bran FGAX is currently not utilized in biorefinery processes. Here, we report selective enzymatic extraction of both single- and double-stranded high-molecular-weight FGAX molecules from corn bran using a bacterial, glucuronoyl-specific glycoside hydrolase family 30 endo-1,4-β-xylanase (EC 3.2.1.8) from Dickeya chrysanthemi (DcXyn30). The enzymatic extraction using DcXyn30 was optimized with respect to temperature, pH, and time to maximize yields of high-molecular-weight polysaccharides. Examination of the enzymatically extracted FGAX using SEC, HPAEC, LC-MS, and NMR analyses (after acid or alkaline hydrolysis) revealed that both single-stranded and double-stranded FGAX were extracted, since diferulate-linkages were present in the extracted FGAX. Furthermore, the NMR analysis indicated the presence of 1,5-linked arabinan dimers suggesting that some of the xylopyranosyl residues in the extracted FGAX contained arabinofuranosyl−arabinofuranosyl substitutions in addition to a significant amount of classical disubstituted xylosyls with α-(1→2)- and α-(1→3)-linked arabinosyl residues. Laccase treatment of the extracted FGAX produced strong hydrogels via oxidative, covalent feruloyl-cross-linking. At pH 6.5, the Myceliophthora thermophila derived laccase produced significantly faster cross-linking kinetics than the laccase from Pleurotus ostreatus as measured rheologically. The data reveal novel insight into corn bran FGAX chemistry and provide a new direction for enzyme-assisted upgrading of corn bran for valuable functional hydrogel applications.

Portable Smartphone Platform Integrated with a Nanoprobe-Based Fluorescent Paper Strip: Visual Monitoring of Glutathione in Human Serum for Health Prognosis
Suyun Chu - ,
Haiqian Wang - ,
Yuanxin Du - ,
Fan Yang - ,
Liang Yang *- , and
Changlong Jiang *
The glutathione (GSH) level in human serum is closely associated with several life-threatening diseases, and tracing the aberrant GSH level can monitor the subhealth conditions at an early stage for human health prognosis. Developing portable and direct read-out mini-devices is an inevitable trend for reliable point-of-care (POC) detection of GSH in real-time/on-site conditions. We herein report a portable smartphone-sensing platform, a ratiometric fluorescence sensor combined with the 3D-printed smartphone device for rapid, sensitive, quantitative, and on-the-spot determination of GSH in human serum. The powerful fluorescence “off–on” nanoprobe was constructed by mixing the blue carbon dots (CDs) and orange gold nanoclusters (AuNCs) with the assistance of copper ions. The quenched fluorescence can be quickly restored upon interacting with GSH, showing a distinct color variation from blue to purple to orange. Integrated with the paper strip printed by the probe ink, the smartphone platform installed with a Color Recognizer App could accomplish sensitive, reliable, and real-time/on-site detection of GSH in human serum, which shows great significance for early disease diagnosis. The constructed smartphone platform is expected to develop into portable home medical equipment to realize convenient and rapid preliminary monitoring and self-assessment of health.

Methanol-Based Chain Elongation with Acetate to n-Butyrate and Isobutyrate at Varying Selectivities Dependent on pH
Kasper D. de Leeuw - ,
Sanne M. de Smit - ,
Sabine van Oossanen - ,
Marinus J. Moerland - ,
Cees J. N. Buisman - , and
David P. B. T. B. Strik *
This publication is Open Access under the license indicated. Learn More
Biomass fermentation technologies offer alternative methods to produce platform chemicals that currently originate from fossil sources. This research showed that an enriched microbiome was capable to produce isobutyrate (i-C4) from acetate via methanol-based chain elongation. A long-term continuous reactor experiment showed that the selectivity for i-C4 and/or n-butyrate (n-C4) could be reversibly adjusted by changing the reactor pH. A reactor pH of 6.75 led to formation of (carbon per total carbon of products) 0.78 n-C4 and 0.024 i-C4, whereas a reactor pH of 5.2 led to a selectivity of 0.24 n-C4 and 0.65 i-C4. This shift in product spectrum was also represented by a shift in microbial composition. The results suggest that a Eubacterium genus is responsible for the formation of n-C4, whereas a Clostridium luticellarii strain is responsible for the formation of a mixture of i-C4 and n-C4. The formation of n-C4 and i-C4 at a low pH was observed to be coupled according to the thermodynamics of isomerization. At a reactor pH of 5.5 and 5.2, the product ratio of i-C4:n-C4 approached 0.69 i-C4:0.31 n-C4, which is the theoretical ratio that would be achieved when determined by the equilibrium of isomerization. Various batch experiments at pH 5.5 and 5.2 confirmed that addition of either n-C4 or i-C4 at the start of the batch would directly lead to the formation of the other butyrate component. Moreover, batch experiments performed at pH 6.5 produced mainly n-C4 and led to the development of a completely different microbiome. The imposed pH is a strong selection pressure that can facilitate changes in product selectivities for n-C4 and i-C4 during methanol-based chain elongation of acetate.

Transfer Hydrogenation of Cinnamaldehyde Catalyzed by Al2O3 Using Ethanol as a Solvent and Hydrogen Donor
Huanjun Wang - ,
Boyang Liu - ,
Fang Liu - ,
Yaning Wang - ,
Xiaocheng Lan - ,
Shiqing Wang - ,
Babar Ali - , and
Tiefeng Wang *
Allylic alcohols produced from α,β-unsaturated aldehydes by selective hydrogenation are useful intermediates and additives in the fine chemicals industry. An efficient process for the catalytic transfer hydrogenation (CTH) of cinnamaldehyde (CMA) to cinnamyl alcohol (CMO) was developed by using ethanol as a solvent and hydrogen donor over Al2O3. Under optimized reaction conditions (120 °C, 12 h), 97.8% conversion of CMA and 96.8% selectivity to CMO were obtained. The solvent effect on catalytic performance was investigated with different primary alcohols, and the results showed that the activity decreased with decreasing polarity of the C2–C5 alcohols, which was ascribed to decreased alcohol–CMA and alcohol–catalyst interaction. In addition, on the basis of the results of poisoning experiments and catalyst characterizations, a reaction mechanism involving a six-membered ring intermediate on acid–base pair active sites of Al2O3 was proposed for the CTH of CMA in ethanol, which was further confirmed by density functional theory calculations. Furthermore, this catalytic system demonstrated good stability and wide compatibility for a range of α,β-unsaturated aldehydes.

Biosynthesis of α-Substituted β-Ketoesters via the Tandem Knoevenagel Condensation–Reduction Reaction Using a Single Enzyme
Xiaolong Liu - ,
Xiangjie Li - ,
Zhelun Wang - ,
Jinlong Zhou - ,
Xinjiong Fan *- , and
Yao Fu *
Saturated α-substituted β-ketoesters are important building blocks in the synthesis of pharmaceuticals and agrochemicals. Herein, we report a one-pot biosynthesis of α-substituted β-ketoesters via Knoevenagel condensation and reduction of the obtained unsaturated alkenes in situ, catalyzed by a single ene-reductase (NerA). A series of inexpensive and readily available aldehydes and 1,3-diketones were condensed and reduced by NerA in aqueous solutions at room temperature. We also noted that low loadings (3 mg/mL) of NerA were sufficient to facilitate the cascade process; both E and Z isomeric intermediates could be reduced effectively, and the overall yield was improved up to 95%. Meanwhile, the method could be applied to a gram preparative-scale synthesis of pharmaceutical intermediates. This process conformed to the concepts of green chemistry and showed advantages for the synthesis of high value saturated α-substituted β-ketoesters.

Potassium-Doped g-C3N4 Achieving Efficient Visible-Light-Driven CO2 Reduction
Shuhui Wang - ,
Jiawei Zhan - ,
Kui Chen - ,
Asad Ali - ,
Linghui Zeng - ,
He Zhao - ,
Wanglai Hu *- ,
Lixin Zhu *- , and
Xiaoliang Xu *
The visible-light-driven CO2 reduction efficiency is largely restrained by the negative photoabsorption and high recombination rate of electron–hole pairs. It is an effective method to increase the efficiency of CO2 photoreduction by doping alkali metal elements to engineer the electronic properties of the catalyst. Here, we report a new study on the potassium-doped g-C3N4 (K-CN) being used for CO2 reduction irradiated by visible light. DFT calculations and XPS tests show that the potassium doping is interlayer doping, changing the electronic structure of g-C3N4. The higher ID/IG value indicates more structural distortion and defects caused by K doping. K-CNs have enhanced visible-light absorption, and PL spectra demonstrate that the introduction of potassium advances the separation and transmission of photoexcited charge carriers, further confirmed by transient photocurrent response experiment. Under visible light, K-CN-7 achieved efficient CO2 reduction without any noble metal as a cocatalyst, with CO formation rates of 8.7 μmol g–1 h–1, which is 25 times that of ordinary g-C3N4. Our work further validates the importance of inhibiting e–/h+ recombination in improving solar energy conversion efficiency while also bringing hope for efficient solar fuel production using g-C3N4.

Extraction Behavior and Separation of Precious and Base Metals from Chloride, Bromide, and Iodide Media Using Undiluted Halide Ionic Liquids
Willem Vereycken - ,
Sofía Riaño - ,
Tom Van Gerven - , and
Koen Binnemans *
Within the framework of metal separations and solvent extraction, chloride media are among the most studied systems. Bromide and iodide media have received much less attention, but can allow a different selectivity during the extraction. In present research, the extraction behavior of several precious and base metal ions, i.e. Pt(IV), Pd(II), Rh(III), Au(III), Cu(II), Fe(III), and Ni(II), from the different halide media was explored using the undiluted ionic liquid Aliquat 336 chloride and its bromide and iodide analogues. A single-step separation of Pt(IV) and Pd(II) from Fe(III) and Ni(II) was possible in the iodide system, but it was found to be incompatible with Au(III) and Cu(II). The chloride and bromide media showed potential for the separation of Au(III), Pd(II), Fe(III), and Cu(II), and their performance was subsequently compared. Fe(III) and Cu(II) were easily separated from Au(III) and Pd(II) via an extraction at low acid concentration followed by scrubbing with water for both systems. However, the stripping showed superior characteristics for the bromide system, where Pd(II) could be recovered using a 0.2 mol L–1 ammonia solution and Au(III) using 1.0 mol L–1 sodium sulfite. The proposed method for the separation of Au(III), Pd(II), Fe(III), and Cu(II) can be relevant for the recycling of waste electric and electronic equipment or analytical applications. The results highlight the importance of considering halides other than chloride, as both the extraction and stripping properties of the system can be changed.

Selective Recovery and Recycling of Germanium for the Design of Sustainable Zeolite Catalysts
Jin Zhang - ,
Qiudi Yue - ,
Michal Mazur - ,
Maksym Opanasenko - ,
Mariya V. Shamzhy *- , and
Jiři Čejka
Germanosilicate zeolites with extra-large-/multidimensional pore systems have a high potential for catalytic applications. However, their insufficient hydrothermal stability, high cost, and lack of strong acid sites limit their use. This work presents a synthetic approach involving post-synthesis degermanation/germanium recycling and remetalation steps for the cost-efficient preparation of Brønsted and Lewis acid zeolite catalysts. Optimization of degermanation conditions (i.e., pH and duration of the leaching treatment) allowed to recover up to 78–94% germanium from ITH, IWW, and UTL zeolites. Further metalation of hydrolyzed IWW zeolites resulted in a set of Al-, Ti-, and Sn-substituted catalysts showing enhanced activity in model acid-catalyzed reactions, such as 1-hexanol tetrahydropyranylation, 1-octene epoxidation, and Baeyer–Villiger oxidation of cyclohexanone. Noticeably, the phase selectivity of zeolite formation upon germanium recycling strongly depended on the method for parent zeolite separation from the leaching solution. In contrast to microfiltration, which produces a versatile source of germanium for the preparation of various zeolites, filtration leads to the formation of germanosilicates with the topology of the parent zeolite regardless of recycling conditions. Such a “memory effect” was rationalized based on the characterization of the germanium source and crystallization products using a combination of techniques (e.g., X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, and transmission electron microscopy).

Green Reconstruction of MIL-100 (Fe) in Water for High Crystallinity and Enhanced Guest Encapsulation
Barbara E. Souza - ,
Annika F. Möslein - ,
Kirill Titov - ,
James D. Taylor - ,
Svemir Rudić - , and
Jin-Chong Tan *
MIL-100 (Fe) is a highly porous metal–organic framework (MOF), considered as a promising carrier for drug delivery and for gas separation and capture applications. However, this functional material suffers from toxic synthesis that may hinder its biomedical use and large-scale production for commercial applications. Herein, we report a “green” mechanochemical water immersion approach to yield highly crystalline MIL-100 (Fe) material. Subsequently, we have harnessed this strategy for facile fabrication of drug@MOF composite systems, comprising (guests) 5-fluorouracil, caffeine, or aspirin encapsulated in the pores of (host) MIL-100 (Fe). Inelastic neutron scattering was uniquely used to probe the guest–host interactions arising from pore confinement of the drug molecules, giving additional insights into the reconstruction mechanism. Our results pave the way for “green” production of MIL-type materials and bespoke guest-encapsulated composites by minimizing the use of toxic chemicals, while enhancing energy efficiency and the material’s life cycle that is central to biotechnological applications.

Regulation of d-Band Electrons to Enhance the Activity of Co-Based Non-Noble Bimetal Catalysts for Hydrolysis of Ammonia Borane
Chenyang Wang - ,
Lanlan Li - ,
Xiaofei Yu - ,
Zunming Lu - ,
Xinghua Zhang - ,
Xixin Wang - ,
Xiaojing Yang *- , and
Jianling Zhao *
The catalytic activity of the catalyst closely depends on its electronic structure, but the relationship between electronic structure and the catalytic activity in the ammonia borane (NH3BH3, AB) catalyzed hydrolysis reaction is still unclear. Here, we prepared Co-based non-noble metal (Fe, Ni, Cu, and Zn) alloy nanoparticles (NPs) and determined the electronic structure by a valence band spectrum (VBS) obtained from X-ray photoelectron spectrometer (XPS) measurement and theoretical calculations. The relationship of the d-band center (εd) and activity exhibits volcano-shape behaviors. The activity of CoCu alloys is superior to other metals, which is due to the electronic structure affecting the adsorption and desorption behavior of water in the hydrolysis reaction. The acid etching method formed SCoCu with different Cu content, and the coexistence of surface defects made the εd further regulated. These results provide new insights into the relationship between the electronic structure of the catalyst and its catalytic AB hydrolysis activity.

Naturally Hydrophobic Foams from Lignocellulosic Fibers Prepared by Oven-Drying
Elisa S. Ferreira - ,
Emily D. Cranston *- , and
Camila A. Rezende *
Lignocellulosic sugarcane biomass underwent an alkaline treatment for partial lignin extraction and then foams with very low apparent density (0.09 g/cm3) were easily obtained by oven-drying aqueous dispersions of fibers. The fiber networks were covalently reinforced through cross-linking by heating the dried material in the presence of citric acid. The lignocellulosic foams were naturally hydrophobic (water contact angle = 117°), without requiring any further chemical modification. The hydrophobicity is attributed to the combination of (1) residual lignin, (2) redeposited lignin that has undergone thermal treatment, (3) the fiber and foam surface roughness, and (4) the structure’s ability to trap air. The cross-linked fiber networks showed shape-recovery properties under compressive stress, high absorption capacity, and mechanical resistance when immersed in water and oil. This work demonstrates that lignocellulosic foams from sugarcane bagasse, processed following low cost and green methods, are promising for selective removal of hydrophobic compounds in aqueous environments and in a range of insulating and packaging products.

Fluorescence Labeling of Technical Lignin for the Study of Phenolic Group Distribution as a Function of the Molecular Weight
Anika Salanti - ,
Marco Orlandi *- , and
Luca Zoia
This publication is Open Access under the license indicated. Learn More
A novel analytical approach based on fluorescence labeling was developed in the effort to increase the understanding of phenolic group distribution in technical lignins. Selective derivatization with a fluorophore (dansyl chloride) of lignin phenolic functionalities was quantitatively achieved under mild reaction conditions. Reference acetylated lignin and labeled lignin were analyzed by gel permeation chromatography (GPC) coupled to a UV–vis detector (set at 280 nm) and a fluorescence detector (λ excitation: 390 nm, λ emission: 550 nm) to discern the dansyl-linked phenol response from the lignin aromatic skeleton input. After data elaboration, valuable information about the phenolic group distribution as a function of molecular weight for different technical lignins was gathered. This novel analytical approach is applied to model lignin polymer thermal protection properties, a useful parameter in lignin valorization strategies.

Selective Photocatalytic Hydrogenation of α,β-Unsaturated Aldehydes on Au/CuCo2O4 Nanotubes under Visible-Light Irradiation
Guowen Hu - ,
Zhi-Peng Huang - ,
Chen-Xia Hu - ,
Ze-Qi Zhang - ,
Rui-Tong Liu - ,
Xiang-Yang Li - ,
Lei Zhang - ,
Qiang Wang *- , and
Hao-Li Zhang *
Photocatalysis for selective organic transformations has received tremendous attention recently. However, how to achieve high selectivity in the photocatalysis of organic reaction remains a challenge. In this work, we reported new hierarchical Au/CuCo2O4 nanotubes for highly selective and efficient photocatalytic hydrogenation of α,β-unsaturated aldehydes. The hierarchical Au/CuCo2O4 nanotubes consisting of CuCo2O4 nanosheets and Au nanoparticles were prepared by the spinning technique in combination with thermal treatment and photoreduction. The produced Au/CuCo2O4 nanotubes were tested as a visible-light-responsive catalyst for the selective hydrogenation of 5-hydroxymethylfurfural to 2,5-furandimethanol. At 20 °C, the catalyst exhibits a high turnover frequency (up to 2727.6 h–1) with nearly 100% selectivity and 93% conversion. Moreover, the Au/CuCo2O4 photocatalyst is highly stable under the reaction conditions and has a wide scope of substrates. The excellent performance of Au/CuCo2O4 can be ascribed to the synergistic effect of Au nanoparticles and semiconducting CuCo2O4 nanosheets, which achieve an efficient interband electron transition in the metal/semiconductor heterostructures. The unique Au/CuCo2O4 heterostructures presented in this work provide not only a green method for the hydrogenation reactions but also an effective way to boost light-induced organic synthesis.

Template Removal from SBA-15 by Ionic Liquid for Amine Grafting: Applications to CO2 Capture and Natural Gas Desulfurization
Yiren Wang - and
Ralph T. Yang *
A new ionic liquid treatment method has been developed for removing the organic template from mesoporous silica SBA-15. Compared with conventional template removal by air calcination, the novel ionic liquid treatment method efficiently removed the organic template at a low temperature and preserved the surface silanol groups. The significantly increased silanol density led to higher amine loadings on amine grafted SBA-15. Consequently, the ionic liquid treated sample showed 63% more CO2 capacity at conditions relevant to CO2 capture from flue gas. Moreover, the ionic liquid treated sample exhibited significantly higher capacities for H2S capture from natural gas as well as CO2 adsorption capacities for direct air capture which were nearly 3 times higher than the conventionally treated sample. The adsorbent stability, the isosteric heats of adsorption, and the effect of moisture were also investigated for the ionic liquid treated sample. The mechanism of template removal by ionic liquid is discussed, and the feasibility of recovery/reuse of the ionic liquid and the template is shown.

Comprehensive Feasibility Assessment of Combined Heat, Hydrogen, and Power Production via Hydrothermal Liquefaction of Saccharina japonica
Haider Niaz - ,
Boris Brigljevic - ,
Yong Boem Park - ,
Hee-Chul Woo - , and
J. Jay Liu *
An increase in population and a decrease in natural resources have shifted the research focus toward renewable energy alternatives such as biofuel produced from algal biomass. The inherently high moisture content of macroalgae makes hydrothermal liquefaction (HTL) a viable approach for using macroalgae to generate renewable energy. This study focuses on experimental and economic feasibility studies regarding HTL of Saccharina japonica as a feedstock for combined heat, hydrogen, and power (CHHP) production. An experimental study was performed using various operating parameters, viz., temperature, reaction time, and macroalgae to water ratio. The optimal experimental conditions resulted in a bio-oil yield of 20.26 wt % and the highest liquefaction conversion of 91.0 wt %. Based on the experimental results, an industrial-scale CHHP process via HTL of S. japonica was developed and the economic viability of this process was evaluated. We assessed the economics of three different designs with different process configurations for 480 000 tons/year of dry macroalgae. The optimal CHHP process provided 17.7 MW of net power, net LP steam production of 60 000 kg/h, and a total hydrogen production of 5104 kg/h with a minimum hydrogen selling price (MHSP) of $3.00 kg–1. The proposed CHHP process based on HTL of S. japonica could be a promising alternative for energy production.

Synthesis of Co-based Prussian Blue Analogues/Dual-Doped Hollow Carbon Microsphere Hybrids as High-Performance Bifunctional Electrocatalysts for Oxygen Evolution and Overall Water Splitting
Xiao Ma - ,
Chengshuai Chang - ,
Yunqiang Zhang - ,
Ping Niu - ,
Xuan Liu *- ,
Shulan Wang *- , and
Li Li *
The development of low-cost non-noble electrocatalysts with high activity and durability is highly desirable for renewable and sustainable energy applications. Prussian blue (PB) analogues with the structure of transition metal–organic frameworks (MOFs) are viewed as attractive candidates for high-performance electrocatalysts, while how to achieve the decoration of metal sites without damage for improved reactivity is still challenging. Herein, a nanocomposite catalyst based on PB analogues on cobalt–nitrogen-doped porous hollow carbon microspheres (PB-Co/Co–N-PHCS) was synthesized by a facile hydrothermal method. Benefiting from multiple active sites, hierarchical porous structure, and high conductive hollow carbon shell, the catalyst showed outstanding electrocatalytic activity and durability for an oxygen evolution reaction (OER). More importantly, PB-Co/Co–N-PHCS also can serve as a bifunctional electrocatalyst for overall water splitting with high durability. This pioneering work provides a clue for the preparation of a new class of high-performance Prussian blue analogue-based hybrid electrocatalysts.

Pyridine Appended Poly(Alkyl Ether) Based Ionogels for Naked Eye Detection of Cyanide Ions: A Metal-Free Approach
Bhaswati Sarkar - ,
Palani Prabakaran - ,
Edamana Prasad *- , and
Ramesh L. Gardas *
The present study initiates applications of ionogels (gels from ionic liquids (ILs)) toward selective detection of cyanide ions (CN–) in aqueous media through a metal-free and colorimetric approach. Three low molecular weight ionogels based on poly(alkyl ether) appended pyridinium ILs—containing ethyl (IL-1), butyl (IL-2), and hexyl (IL-3) substituents—were designed, synthesized, and used for cyanide sensing. All ILs formed unique thermoreversible gels in aqueous solutions of dimethylformamide, dimethylsulfoxide, ethanol, methanol, and dioxane. The self-assembled structure of the ionogels has been characterized by temperature-dependent 1H nuclear magnetic resonance, powder X-ray diffraction, scanning electron microscopy, atomic force microscopy, and rheology. The as-synthesized ionogels exhibited a rapid color change from yellow to saffron upon interaction with CN– ions (0.1 equiv). The remarkable features of this detection are that (a) the gel color was changed without losing the physical structural integrity; (b) the color change is reversible in the presence of a proton source, assuring the reusability of the material; and (c) the color change can be identified by the naked eye. The mechanism of the sensing has been investigated using 1H nuclear magnetic resonance titration experiments. All the ionogels showed a CN– response at micromolar range in the solution media and at 0.1 equiv to the gelator concentration in the gel medium. Results taken together suggest that as-prepared gels are useful for developing environmentally friendly portable kits for testing CN– in aqueous samples with a response time in seconds.

Single Atoms Anchored on Cobalt-Based Catalysts Derived from Hydrogels Containing Phthalocyanine toward the Oxygen Reduction Reaction
Yuanyuan Fu - ,
Dawei Xu - ,
Yefei Wang - ,
Xuhui Li - ,
Zhengbo Chen *- ,
Kai Li - ,
Zhongfeng Li - ,
Lirong Zheng - , and
Xia Zuo *
Herein, a novel hydrogel-derived three-dimensional network-like nanostructured CoOX/Co–N–C(800) catalyst was synthesized. CoOX nanoparticles are embedded on N-doped carbon with single Co atoms anchored after pyrolysis. The as-prepared CoOX/Co–N–C(800) catalyst possesses excellent electrochemical performance toward the oxygen reduction reaction with a positive onset and half-wave potential of 0.95 and 0.88 V (vs RHE), respectively, including almost a four-electron pathway (3.97) and better durability compared with the 20% commercial Pt/C catalyst in an alkaline electrolyte. Also, the results demonstrate that the high performance is attributed to the synergistic effect of CoOX nanoparticles and single Co atoms.

In Situ Construction of a Mn2+-Doped Ni3S2 Electrode with Highly Enhanced Urea Oxidation Reaction Performance
Han Yang - ,
Mengwei Yuan - ,
Zemin Sun - ,
Di Wang - ,
Liu Lin - ,
Huifeng Li - , and
Genban Sun *
Urea, as a prospective energy source, is rarely utilized for lack of effective catalysts to overcome its sluggish kinetics during its electrolysis. Exploiting low-cost and high-efficiency catalysts to accelerate the urea oxidation reaction (UOR) does make sense as it can relieve not only energy shortage but also the water contamination problems. In this work, the Ni3S2 nanosheets grown on the Ni foam with different amounts of Mn2+ doping were developed as useful electrocatalysts toward UOR. The experimental and computational methods were performed to explore the properties of obtained samples. We found that the doping of Mn2+ could distinctly regulate the charge distribution of Ni3S2 by which the performance was observably optimized. We also compared the behaviors of obtained catalysts with various dopant concentrations of Mn2+. Especially, Ni3S2 grown on the Ni foam with the addition of 0.2 mmol of Mn2+ exhibits splendid properties with a lower potential and superior longevity, which can achieve a current density of 100 mA cm–2 at a voltage of only 1.397 V (vs reversible hydrogen electrode) in 1.0 M KOH containing 0.5 M urea solution, indicating that our findings can serve as promising electrocatalysts for urea electrolysis.

Amine-Based Ionic Liquid for CO2 Capture and Electrochemical or Thermal Regeneration
Sahag Voskian - ,
Paul Brown - ,
Cameron Halliday - ,
Krzysztof Rajczykowski - , and
T. Alan Hatton *
An ethylenediamine-functionalized ionic liquid (IL) was synthesized for CO2 capture from industrial gases, with good CO2 absorption capacity of around 0.95 mmol (42 mg) of CO2/g of IL at 35 °C. In contrast to conventional gas desorption via utilization of an energy intensive thermal swing, CO2 was released on competitive complexation of the amines with cupric ions introduced to the ionic liquid electrolyte by the oxidation of a copper electrode. The electrolyte was regenerated by electrodeposition of cupric ions at the cathode. This work emphasizes the importance of electrodeposition from metal-containing ILs and the potential for new recyclable catalysts.

Integrated Biorefining Approach for the Production of Polyhydroxyalkanoates from Enzymatically Hydrolyzed Rapeseed Meal under Nitrogen-Limited Conditions
Phavit Wongsirichot - ,
Maria Gonzalez-Miquel - , and
James Winterburn *
Rapeseed meal (RSM) is an ideal candidate for biorefining due to its abundance, low cost, and valorizable factions, including protein and lignocellulose. High levels of residual nitrogen have hampered the application of RSM in fermentations where nitrogen-limitation is required, such as the production of polyhydroxyalkanoate (PHA) by Pseudomonas putida. A comprehensive multifactorial study using central composite design was conducted on enzyme hydrolysis of untreated and post-protein extraction RSM. It was found that a combination of protein extraction and enzyme hydrolysis was crucial in producing a fermentation medium with a high carbon to nitrogen ratio from RSM (36–38 g glucose-C g N–1). Significant PHA accumulation in P. putida KT2440 was achieved with said medium in shake flask (8.18–9.34%). Furthermore, process scalability was addressed, and the medium was shown to be viable at a 1.5 l bioreactor-scale. Through this work the importance of integrated biorefining is demonstrated, as omitting either the enzyme hydrolysis or protein extraction would compromise the scheme. In addition to potentially improving the economics of biomass valorization, integrated biorefining widens the range of biomass applications. This study has achieved the largest PHA accumulation to date for RSM as the sole carbon and nitrogen source and presents important insights for the use of high-nitrogen wastes in nitrogen-limiting applications.

Second-Generation Biofuel Production from the Marine Filter Feeder Ciona intestinalis
Kateřina Hrůzová - ,
Leonidas Matsakas - ,
Anthi Karnaouri - ,
Fredrik Norén - ,
Ulrika Rova - , and
Paul Christakopoulos *
This publication is Open Access under the license indicated. Learn More
Biofuels are essential for transitioning to a sustainable society. This switch can be achieved by introducing novel feedstocks and technologies for efficient and economically feasible biofuel production. Second-generation biofuels are particularly advantageous, as they are produced from nonedible lignocellulosic biomass derived primarily from agricultural byproducts. Ciona intestinalis, a marine filter feeder, is cultivated to produce fish feed from the invertebrate’s inner tissue body. This process generates also vast amounts of a renewable side stream, namely the tunicate’s external cellulose-rich tunic. The aim of the present study was to evaluate the potential of the C. intestinalis tunic as a novel feedstock for bioethanol production. For this purpose, organosolv fractionation of the tunic was optimized to increase cellulose content. Enzymatic saccharification of the pretreated biomass was assessed to identify the most promising materials, which were subsequently utilized as carbon source in fermentation trials. Under optimal conditions, a titer of 38.7 g/L of ethanol, with a yield of 78.3% of the maximum theoretical, was achieved. To the best of our knowledge, this is the first report whereby organosolv pretreated tunic biomass is valorized toward bioethanol production; the current work paves the way for incorporating tunicates in bioconversion processes for the generation of biofuels and other biobased chemicals.

Core–Shell Co, Zn Bimetallic Selenide Embedded Nitrogen-Doped Carbon Polyhedral Frameworks Assist in Sodium-Ion Battery Ultralong Cycle
Zheng Zhang - ,
Ying Huang *- ,
Xudong Liu - ,
Xin Wang - , and
Panbo Liu
Sodium-ion batteries (SIBs) have become the best alternative to lithium-ion batteries. However, it is difficult to meet the efficiency of SIBs using graphite. Transition-metal selenides are expected to be ideal anode materials for SIBs, but some problems still need to be solved, such as poor conductivity and volume expansion. Here, we successfully synthesized a core–shell structure ZnSe@CoSe2/NC composite using ZIF-8@ZIF-67 as a precursor. The in situ decorated ZnSe and CoSe2 nanoparticles on the NC polyhedral framework provide a rich active site for the entire electrode. In addition, the NC can simultaneously increase the conductivity and alleviate the volume effect generated during the cycling process. The ZnSe@CoSe2/NC composites exhibit excellent electrochemical performance when used in SIB anode materials. When the current density is 0.1 A g–1, the reversible capacity is 499.1 mA h g–1 after 100 cycles. When the current density is increased to 1.0 A g–1, a reversible capacity of 273.5 mA h g–1 after 4000 cycles is delivered. In addition, the ZnSe@CoSe2/NC composite also exhibits superior rate performance. The sodium reaction kinetics of the ZnSe@CoSe2/NC composite was analyzed to explain its outstanding electrochemical performance. These results reveal the enormous potential of ZnSe@CoSe2/NC composites in building efficient SIBs.

Integrating Mixed Metallic Selenides/Nitrogen-Doped Carbon Heterostructures in One-Dimensional Carbon Fibers for Efficient Oxygen Reduction Electrocatalysis
Li-Ping Lv - ,
Pingping Du - ,
Pengbo Liu - ,
Xiaopeng Li - , and
Yong Wang *
Developing electrocatalysts for oxygen reduction reaction (ORR) with superior catalytic activity, long-period stability, and low price is extremely desirable but full of challenges. Hybrid nitrogen-doped carbon nanofibers encapsulated with mixed metallic selenides of ZnSe and CoSe2 (assigned as Co1–xZnxSe, x represents the molar ratio of Zn/Co) nanoparticles are successfully prepared and denoted as Co1–xZnxSe@NCF-y (y represents the carbonization temperature). By controlling the ratio of Zn to Co and the carbonization temperature, the obtained Co0.62Zn0.38Se@NCF-800 fibers with a large specific surface area (385 m2 g–1) and a high content of nitrogen species (8.39 wt %) exhibit outstanding ORR electrocatalytic activity with a half-wave potential of 0.83 V (vs reversible hydrogen electrode, RHE), a limiting current density of 5.05 mA cm–2, an excellent catalytic stability, and methanol tolerance. The superior ORR catalytic performances can be first explained by the hierarchical nanoparticles-in-fiber structure, which helps suppress the particle agglomeration, increase the structural stability, and promote the mass/electron transportation. The mixed metallic selenides are also believed to facilitate the electronic conductivity through redistribution of electrons from the metallic selenides to the nitrogen-doped carbon layers. Meanwhile, the highly nitrogen-doped carbon layers act as supports for metallic selenides to exhibit good electrocatalytic performances and electrochemical stability.

Fabricating Chitin Paper from Self-Assembled Nanochitins
Jun-ichi Kadokawa *- ,
Satoshi Idenoue - , and
Kazuya Yamamoto
Herein, we report the fabrication of paperlike chitin sheets (chitin paper) by the extensive entanglement of self-assembled nanochitins formed using a bottom-up approach involving stepwise regeneration from a solution of chitin in a deep eutectic solvent composed of 1-allyl-3-methylimidazolium chloride and thiourea, with additives such as benzylamine. The successful process involves preliminary sedimentation, promoted addition of the additives to the solution, with subsequent dispersive regeneration with methanol. The appearance of the regenerated chitins, namely, sheet or powder, depends on the amount of benzylamine used. The nanoscale morphology of the chitin paper was confirmed by scanning electron microscopy, and it depends on the additive used. The mechanical properties of the chitin paper were evaluated by tensile testing and compared with those of cellulose filter paper.

Pushing the Limits of SNG Process Intensification: High GHSV Operation at Pilot Scale
Jordi Guilera *- ,
Tim Boeltken - ,
Friedemann Timm - ,
Ignasi Mallol - ,
Andreina Alarcón - , and
Teresa Andreu
Process intensification leads to a substantially smaller process technology. In this work, we present a combination of an active microsize catalyst and an effective microstructured reactor technology for CO2 methanation. The product of the reaction is renewable synthetic natural gas which can be injected into the existing gas infrastructure. The designed process was evaluated at pilot scale (37 kW electrolyzer) in a relevant environment using sewage biogas and a CO2 waste stream as carbon sources. The desired gas quality was obtained in a 2-step synthesis process at moderate pressure using a decreasing temperature profile (T = 275–475 °C) and water sequestration. Temperature profiles were adjusted by vaporizing water, compressed air, and heating cartridges. It was observed that pressure, carbon feedstock, and GHSV had an impact on the product gas quality. At the minimum pressure (P = 5 bar·g) for direct gas grid injection purposes, the process worked successfully at 31 500 h–1 using upgraded CO2 and 37 500 h–1 using biogas. This represents a reduction of 4 times the volume of the commercial reference. Accordingly, the limits of CO2 methanation process intensification were clearly crossed by the combination of reactor and catalyst miniaturization.

Antibacterial and Degradable Thioimidazolium Poly(ionic liquid)
Christene Anne Smith - ,
Vincenzo Alessandro Cataldo - ,
Thomas Dimke - ,
Ina Stephan - , and
Ryan Guterman *
This publication is Open Access under the license indicated. Learn More
New antibacterial agents are urgently required to fight the emergence of antibiotic-resistant bacteria. We recently synthesized the first thioimidazolium ionene, which has antibacterial properties and can degrade in various media. This dual functionality is crucial in order to limit the environmental impact of these biocides. We have found that our polymer is stronger than benzalkonium chloride (BAC) against Pseudomonas aeruginosa and also readily degrades in the presence of base, while remaining stable in acidic environments. These results highlight a new emerging class of antibacterial degradable polymers.

Sustainability Analysis for the Wastewater Treatment Technical Route for Coal-to-Synthetic Natural Gas Industry through Zero Liquid Discharge Versus Standard Liquid Discharge
Jingwei Yang - ,
Zhengkun Hou - ,
Fanqing Meng - ,
Jianguang Qi - ,
Zhaoyou Zhu - ,
Yinglong Wang - ,
Jun Gao - , and
Peizhe Cui *
In recent years, the rapid development of the coal chemical industry has triggered problems related to supply and demand imbalances of the regional water resources in China. Water resources have become the main bottleneck restricting the sustainable development of the coal chemical industry. To achieve cleaner production, China has issued policies on zero liquid discharge for the coal chemical industry, especially for coal gasification wastewater. However, to achieve zero liquid discharge targets, coal gasification companies have to add more processes to support and complete the sustainable reuse of wastewater. To scientifically evaluate this sustainability problem, in this study, we conducted a life cycle assessment of water consumption, costs, and environmental impacts for the zero liquid discharge route of the fixed-bed coal gasification wastewater treatment process. The results reveal that the total water consumption of the zero liquid discharge route is greater than the one of the standard liquid discharge route. Reusing 1 m3 of water would consume an extra 1.64 m3 of water. This is because of the large amount of indirect water consumption caused by the extra high power consumption. Moreover, the life cycle cost of the zero liquid discharge route is approximately twice that of the standard liquid discharge route while the total environmental impact is 1.15 times that of the standard liquid discharge route and 1.03 times for total human health impact. The zero liquid discharge route increases water consumption, incurs higher costs, and causes more serious environmental impacts. Therefore, the zero liquid discharge route does not meet the requirements of cleaner production and sustainable development.

Life Cycle Assessment and Technoeconomic Analysis of Thermochemical Conversion Technologies Applied to Poultry Litter with Energy and Nutrient Recovery
Raaj R. Bora - ,
Musuizi Lei - ,
Jefferson W. Tester - ,
Johannes Lehmann - , and
Fengqi You *
Thermochemical technologies provide promising pathways to recover energy and reduce environmental impacts from biomass wastes. Poultry manure or litter additionally provides an opportunity for recovering and recycling nutrients and producing valuable soil amendments. This study compared the life cycle environmental impacts and technoeconomic performance of six thermochemical technologies for treating poultry litter waste—slow pyrolysis, fast pyrolysis, gasification, hydrothermal liquefaction, hydrothermal carbonization, and supercritical water gasification—with direct land application. Using life cycle assessment (LCA), the technologies were compared through 15 different environmental impact categories (midpoints) using the IMPACT 2002+ method. On converting the midpoints to damage categories (end points), it was found that these technologies outperformed the conventional land application method with respect to human health (92–149% improvement), climate change impact (15–53% improvement), ecosystem quality (124–160% improvement), and resource depletion (−24–530% improvement). The technoeconomic analysis (TEA) identified carbon price (breakeven of $127/1000 kg CO2 equiv for slow pyrolysis) and high capital costs as influential parameters for large-scale applications of these technologies. The TEA results were most sensitive to carbon price and transportation distance (0.69 and 0.52% changes in revenue per change in input, respectively).

Bio-Based Radish@PDA/PEG Sandwich Composite with High Efficiency Solar Thermal Energy Storage
Yuhui Xie - ,
Weijie Li - ,
Haowei Huang - ,
Dexuan Dong - ,
Xinya Zhang - ,
Li Zhang - ,
Ying Chen - ,
Xinxin Sheng *- , and
Xiang Lu *
Phase change materials with desirable light-thermal conversion ability are particularly attractive for solar energy harvesting and storage. Herein, we demonstrate that the combination of efficient light-thermal conversion, excellent thermal property, and reliability can be achieved via the construction of a novel form-stable phase change composite material, that is, Radish@PDA/PEG with a sandwich structure. A 3D porous structure derived from radish via freeze-drying is adopted as the substrate; then, self-polymerization of dopamine is initiated in the surface of Radish to produce a layer of polydopamine (PDA). Finally, polyethylene glycol (PEG) impregnation via vacuum infusion is applied to form the Radish@PDA/PEG composite. These results prove that the incorporation of interlayer PDA can not only improve the strength of the porous structure to protect the PEG from leakage, but also enhance the encapsulation capacity of PEG and light absorption ability of the composite. The preparation method is based on common biomass with green chemicals and thus provides a general way to prepare eco-friendly and biodegradable composite with promising applications in light thermal energy management.

Hierarchical Porous g-C3N4 Coupled Ultrafine RuNi Alloys as Extremely Active Catalysts for the Hydrolytic Dehydrogenation of Ammonia Borane
Yong-Ting Li - ,
Xiao-Li Zhang - ,
Zhi-Kun Peng *- ,
Pu Liu - , and
Xiu-Cheng Zheng *
It is a crucial and urgent task to develop high performance catalysts for the hydrolysis of ammonia borane (NH3BH3, AB), which is presently thought to be an effective strategy for hydrogen generation. In this work, we immobilize the ultrafine RuNi alloy nanoparticles in the network of hierarchical porous g-C3N4 thin sheets with a facile adsorption–in situ reduction method. The structural and physicochemical properties of the as-prepared catalysts are studied using various techniques. The influence of different molar ratios of Ru to Ni in the catalysts on the hydrolytic dehydrogenation rate of AB is investigated to optimize the best one. The detailed reaction kinetics and the enhancing effect of NaOH with different dosages on the hydrolysis rate are studied through a series of experiments. Catalyzed by the optimal catalysts (denoted as Ru0.5Ni0.5/p-g-C3N4), the hydrolysis reaction is first-order and near zero-order relative to the Ru and AB concentrations, respectively. The corresponding turnover frequency reaches 840.3 min–1, and the apparent activation energy is as low as 14.1 kJ mol–1, which are greatly superior to many similar or counterpart catalysts previously reported. The results indicate the potential of the bimetallic alloy catalysts for the hydrolytic dehydrogenation of hydrogen storage materials.
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