An innovative strategy was proposed by integration of membrane contactor(MC)with biphasic solvent for efficient CO_(2) capture from flue gas.The accessible fly ash-based ceramic membrane(CM)underwent hydrophobic modif...An innovative strategy was proposed by integration of membrane contactor(MC)with biphasic solvent for efficient CO_(2) capture from flue gas.The accessible fly ash-based ceramic membrane(CM)underwent hydrophobic modification through silane grafting,followed by fluoroalkylsilane decoration,to prepare the superhydrophobic membrane(CSCM).The CSCM significantly improved resistance to wetting by the biphasic solvent,consisting of amine(DETA)and sulfolane(TMS).Morphological characterizations and chemical analysis revealed the notable enhancements in pore structure and hydrophobic chemical groups for the modified membrane.Predictions of wetting/bubbling behavior based on static wetting theory referred the liquid entry pressure(LEP)of CSCM increased by 20 kPa compared to pristine CM.Compared with traditional amine solvents,the biphasic solvent presented the expected phase separation.Performance experiments demonstrated that the CO_(2) capture efficiency of the biphasic solvent increased by 7%,and the electrical energy required for desorption decreased by 32%.The 60-h continuous testing and supplemental characterization of used membrane confirmed the excellent adaptability and durability of the CSCMs.This study provides a potential approach for accessing hydrophobic ceramic membranes and biphasic solvents for industrial CO_(2) capture.展开更多
Phosphoric acid treated niobic acid(NbP)was used for the dehydration of xylose to furfural in biphasic solvent system,which was found to exhibit the best performance among the tested catalysts.The excellent performanc...Phosphoric acid treated niobic acid(NbP)was used for the dehydration of xylose to furfural in biphasic solvent system,which was found to exhibit the best performance among the tested catalysts.The excellent performance of NbP could be explained by the better synergistic cooperation between Bro¨nsted and Lewis acid sites.Moreover,NbP showed good stability and no obvious deactivation or leaching of Nb could be observed after six continuous recycles.展开更多
This study focused on enhancing the efficiency of methane upgrading and reducing energy consumption in the biogas upgrading process through the use of biphasic solvents.An aqueous-based biphasic solvent,comprising met...This study focused on enhancing the efficiency of methane upgrading and reducing energy consumption in the biogas upgrading process through the use of biphasic solvents.An aqueous-based biphasic solvent,comprising methyl monoethanolamine(MMEA),N-methyldiethanolamine(MDEA),and 1-butyl-3-methylimidazolium tetrafluoroborate(ItFB),was meticulously prepared.The biogas upgrading effect,regeneration efficiency,regeneration energy consumption,economic viability,selectivity,and phase separation characteristics of this absorbent were systematically analyzed.Various parameters,including different inlet flow rates,stirring rate,methane inlet concentrations,reaction temperatures,and amine mixing ratios,were adjusted to investigate their impact.A comprehensive evaluation was conducted on the biogas upgrading effect and substance migration trends of the biphasic solvent.Optimal process parameters were determined,demonstrating the favorable impact of the biphasic solvent on biogas upgrading.The upgraded gas achieved a methane purity exceeding 96%,and the regeneration energy consumption decreased by 44.27% compared to 30 wt.%MEA,resulting in a more than 50% improvement in economic efficiency.The interaction between the ionic liquid and carbamate facilitated the phase separation process,with carbon enrichment after separation exceeding 95%.This enhancement significantly contributed to the improvement of regeneration energy consumption.The study thus concludes that biphasic solvents,exemplified by the described aqueous-based solution,offer a promising avenue for effective biogas upgrading with notable advancements in economic and energy efficiency.展开更多
Asymmetric reduction of 3,5-bistrifluoromethyl acetophenone to produce(S)-3,5-bistrifluoromethylphenyl ethanol was successfully carried out with sodium alginate immobilized Saccharomyces rhodotorula cells in an aqueou...Asymmetric reduction of 3,5-bistrifluoromethyl acetophenone to produce(S)-3,5-bistrifluoromethylphenyl ethanol was successfully carried out with sodium alginate immobilized Saccharomyces rhodotorula cells in an aqueous-organic solvent biphasic system.The possible influential factors were examined thoroughly according to their effects on conversion rate and e.e of the product.Organic solvents were rated by their biocompatibility and conversion potential.The immobilized cells [125 mg/mL in 20 mmol/L Tris-HCl buffer and 5%(j) octane at pH 8] showed the best conversion with a substrate concentration of 1.42 g/L at 30℃ with glucose as co-substrate for cofactor regeneration.Sequential 8-batch process was carried out with immobilized cells with a slow decrease in conversion and e.e.The immobilized cells showed stable catalytic activity with 50% reserved activity and are superior especially in reusability in comparison with resting cells.展开更多
Asymmetric synthesis of (-)-1-trimethylsilyl-ethanol with immobilized Saccharomyces cerevisiae cells in water/organic solvent biphasic system was studied. The effects of shake speed, hydrophobicity of organic solvent,...Asymmetric synthesis of (-)-1-trimethylsilyl-ethanol with immobilized Saccharomyces cerevisiae cells in water/organic solvent biphasic system was studied. The effects of shake speed, hydrophobicity of organic solvent, volume ratio of water phase to organic phase, pH value of aqueous phase and reaction temperature on the initial reaction rate, maximum yield and enantiomeric excess (ee) of the product were systematically explored. All the above-mentioned factors had significant influence on the reaction. n-Hexane was found to be the best organic solvent for the reaction. The optimum shake speed, volume ratio of water phase to organic phase, pH value and reaction temperature were 150 r.min-1, 1/2, 8 and 30 ℃ respectively, under which the maximum yield and enantiomeric excess of the product were as high as 96.8% and 95.7%, which are 15% and 16% higher than those of the corresponding reaction performed in aqueous phase. To our best knowledge, this is the most satisfactory result obtained.展开更多
Phase change absorbents based on amine chemical absorption for CO_(2)capture exhibit energy-saving potential,but generally suffer from difficulties in CO_(2)regeneration.Alcohol,characterized as a protic reagent with ...Phase change absorbents based on amine chemical absorption for CO_(2)capture exhibit energy-saving potential,but generally suffer from difficulties in CO_(2)regeneration.Alcohol,characterized as a protic reagent with a low dielectric constant,can provide free protons to the rich phase of the absorbent,thereby facilitating CO_(2)regeneration.In this investigation,N-aminoethylpiperazine(AEP)/sulfolane/H_(2)O was employed as the liquid-liquid phase change absorbent,with alcohol serving as the regulator.First,appropriate ion pair models were constructed to simulate the solvent effect of the CO_(2)products in different alcohol solutions.The results demonstrated that these ion pair products reached the maximum solvation-free energy(△E_(solvation))in the rich phase containing ethanol(EtOH).Desorption experiment results validated that the inclusion of EtOH led to a maximum regeneration rate of 0.00763 mol/min,thus confirming EtOH’s suitability as the preferred regulator.Quantum chemical calculations and^(13)C NMR characterization were performed,revealing that the addition of EtOH resulted in the partial conversion of AEP-carbamate(AEPCOO−)into a new product known as ethyl carbonate(C_(2)H_(5)OCOO−),which enhanced the regeneration reactivity.In addition,the decomposition paths of different CO_(2)products were simulated visually,and every reaction’s activation energy(△E_(act))was calculated.Remarkably,the△E_(act)for the decomposition of C_(2)H_(5)OCOO−(9.465 kJ/mol)was lower than that of the AEPCOO−(26.163 kJ/mol),implying that CO_(2)was more likely to be released.Finally,the regeneration energy consumption of the alcohol-regulated absorbentwas estimated to be only 1.92 GJ/ton CO_(2),which had excellent energy-saving potential.展开更多
5-Hydroxymethylfurfural(5-HMF)is one of the important bio-based platform compounds,and the catalytic conversion of glucose to 5-HMF is a highly desirable approach that is receiving increasing attention.Herein,we repor...5-Hydroxymethylfurfural(5-HMF)is one of the important bio-based platform compounds,and the catalytic conversion of glucose to 5-HMF is a highly desirable approach that is receiving increasing attention.Herein,we reported the synthesis of lignin-derived carbon supported tin oxides(SnOx/LC)catalyst via a two-step hydrothermal-pyrolytic method using wheat straw alkali lignin as a cost-effective carbon source with high carbon content.The key preparation conditions of the catalyst and its catalytic conditions for the conversion of glucose to 5-HMF were investigated,respectively.Results show that under the preparation conditions of tin tetrachloride dosage of 3.0 mmol and pyrolysis temperature of 500 ℃,the optimized catalyst(3.0-SnOx/LC-500)with a high yield of 63.4%exhibits good catalytic performance of 5-HMF yield of 50.1%and reaction selectivity of 86.0%under the optimum conditions of reaction temperature and time of 190 ℃ and 3 h,initial glucose concentration of 10%(mass),3.0-SnOx/LC-500 dosage of 100 mg in a biphasic solvent system of volume ratio of water to tetrahydrofuran of 1:4.In addition,3.0-SnOx/LC-500 exerts an excellent reusability in a five-cycle experiment.Furthermore,SnOx/LC was characterized in detail using X-ray diffraction patterns(XRD),X-ray photoelectron spectroscopy(XPS),Brunauer-Emmett-Teller(BET),ammonia temperature-programmed-desorption(NH3-TPD),pyridine adsorption infrared spectroscopy(Py-FTIR),scanning electron microscope(SEM)and thermal gravimetric analysis(TGA).Results indicate that Brønsted acid sites and Lewis acid sites coexist on 3.0-SnOx/LC-500,and more Sn^(4+),as well as a proper ratio of weak acidity to medium acidity,are conductive to its catalytic performance in glucose-to-5-HMF reaction.展开更多
基金supported by the National Key R&D Program of China(2023YFF0614301,2023YFC3707004,and 2018YFB0604302)Fundamental Research Funds for the Central Universities(No.2022MS041)+1 种基金National Natural Science Foundation of China(No.22106084)Tsinghua University Initiative Scientific Research Program(2023Z02JMP001).
文摘An innovative strategy was proposed by integration of membrane contactor(MC)with biphasic solvent for efficient CO_(2) capture from flue gas.The accessible fly ash-based ceramic membrane(CM)underwent hydrophobic modification through silane grafting,followed by fluoroalkylsilane decoration,to prepare the superhydrophobic membrane(CSCM).The CSCM significantly improved resistance to wetting by the biphasic solvent,consisting of amine(DETA)and sulfolane(TMS).Morphological characterizations and chemical analysis revealed the notable enhancements in pore structure and hydrophobic chemical groups for the modified membrane.Predictions of wetting/bubbling behavior based on static wetting theory referred the liquid entry pressure(LEP)of CSCM increased by 20 kPa compared to pristine CM.Compared with traditional amine solvents,the biphasic solvent presented the expected phase separation.Performance experiments demonstrated that the CO_(2) capture efficiency of the biphasic solvent increased by 7%,and the electrical energy required for desorption decreased by 32%.The 60-h continuous testing and supplemental characterization of used membrane confirmed the excellent adaptability and durability of the CSCMs.This study provides a potential approach for accessing hydrophobic ceramic membranes and biphasic solvents for industrial CO_(2) capture.
基金supported by the Natural Science Foundation of China (No.21106143)100-talent project of Dalian Institute of Chemical Physics (DICP)the Independent Innovation Foundation of State Key Laboratory of Catalysis (No.R201113)
文摘Phosphoric acid treated niobic acid(NbP)was used for the dehydration of xylose to furfural in biphasic solvent system,which was found to exhibit the best performance among the tested catalysts.The excellent performance of NbP could be explained by the better synergistic cooperation between Bro¨nsted and Lewis acid sites.Moreover,NbP showed good stability and no obvious deactivation or leaching of Nb could be observed after six continuous recycles.
基金the financial support by the National Natural Science Foundation of China(No.22376115)funded by the Shanghai Tongji Gao Tingyao Environmental Science&Technology Development Foundation(China).
文摘This study focused on enhancing the efficiency of methane upgrading and reducing energy consumption in the biogas upgrading process through the use of biphasic solvents.An aqueous-based biphasic solvent,comprising methyl monoethanolamine(MMEA),N-methyldiethanolamine(MDEA),and 1-butyl-3-methylimidazolium tetrafluoroborate(ItFB),was meticulously prepared.The biogas upgrading effect,regeneration efficiency,regeneration energy consumption,economic viability,selectivity,and phase separation characteristics of this absorbent were systematically analyzed.Various parameters,including different inlet flow rates,stirring rate,methane inlet concentrations,reaction temperatures,and amine mixing ratios,were adjusted to investigate their impact.A comprehensive evaluation was conducted on the biogas upgrading effect and substance migration trends of the biphasic solvent.Optimal process parameters were determined,demonstrating the favorable impact of the biphasic solvent on biogas upgrading.The upgraded gas achieved a methane purity exceeding 96%,and the regeneration energy consumption decreased by 44.27% compared to 30 wt.%MEA,resulting in a more than 50% improvement in economic efficiency.The interaction between the ionic liquid and carbamate facilitated the phase separation process,with carbon enrichment after separation exceeding 95%.This enhancement significantly contributed to the improvement of regeneration energy consumption.The study thus concludes that biphasic solvents,exemplified by the described aqueous-based solution,offer a promising avenue for effective biogas upgrading with notable advancements in economic and energy efficiency.
文摘Asymmetric reduction of 3,5-bistrifluoromethyl acetophenone to produce(S)-3,5-bistrifluoromethylphenyl ethanol was successfully carried out with sodium alginate immobilized Saccharomyces rhodotorula cells in an aqueous-organic solvent biphasic system.The possible influential factors were examined thoroughly according to their effects on conversion rate and e.e of the product.Organic solvents were rated by their biocompatibility and conversion potential.The immobilized cells [125 mg/mL in 20 mmol/L Tris-HCl buffer and 5%(j) octane at pH 8] showed the best conversion with a substrate concentration of 1.42 g/L at 30℃ with glucose as co-substrate for cofactor regeneration.Sequential 8-batch process was carried out with immobilized cells with a slow decrease in conversion and e.e.The immobilized cells showed stable catalytic activity with 50% reserved activity and are superior especially in reusability in comparison with resting cells.
基金Supported by the National Natural Science Foundation of China(No.20076019)the Natural Science Foundation of Guang-dong Province(No.000444).
文摘Asymmetric synthesis of (-)-1-trimethylsilyl-ethanol with immobilized Saccharomyces cerevisiae cells in water/organic solvent biphasic system was studied. The effects of shake speed, hydrophobicity of organic solvent, volume ratio of water phase to organic phase, pH value of aqueous phase and reaction temperature on the initial reaction rate, maximum yield and enantiomeric excess (ee) of the product were systematically explored. All the above-mentioned factors had significant influence on the reaction. n-Hexane was found to be the best organic solvent for the reaction. The optimum shake speed, volume ratio of water phase to organic phase, pH value and reaction temperature were 150 r.min-1, 1/2, 8 and 30 ℃ respectively, under which the maximum yield and enantiomeric excess of the product were as high as 96.8% and 95.7%, which are 15% and 16% higher than those of the corresponding reaction performed in aqueous phase. To our best knowledge, this is the most satisfactory result obtained.
基金supported by the National Natural Science Foundation of China(Nos.22278168 and 22276064)the MOE Key Laboratory of Resources and Environmental System Optimization(No.KLRE-KF202205)the Science and Technology Project of Fujian province(No.2022Y3007).
文摘Phase change absorbents based on amine chemical absorption for CO_(2)capture exhibit energy-saving potential,but generally suffer from difficulties in CO_(2)regeneration.Alcohol,characterized as a protic reagent with a low dielectric constant,can provide free protons to the rich phase of the absorbent,thereby facilitating CO_(2)regeneration.In this investigation,N-aminoethylpiperazine(AEP)/sulfolane/H_(2)O was employed as the liquid-liquid phase change absorbent,with alcohol serving as the regulator.First,appropriate ion pair models were constructed to simulate the solvent effect of the CO_(2)products in different alcohol solutions.The results demonstrated that these ion pair products reached the maximum solvation-free energy(△E_(solvation))in the rich phase containing ethanol(EtOH).Desorption experiment results validated that the inclusion of EtOH led to a maximum regeneration rate of 0.00763 mol/min,thus confirming EtOH’s suitability as the preferred regulator.Quantum chemical calculations and^(13)C NMR characterization were performed,revealing that the addition of EtOH resulted in the partial conversion of AEP-carbamate(AEPCOO−)into a new product known as ethyl carbonate(C_(2)H_(5)OCOO−),which enhanced the regeneration reactivity.In addition,the decomposition paths of different CO_(2)products were simulated visually,and every reaction’s activation energy(△E_(act))was calculated.Remarkably,the△E_(act)for the decomposition of C_(2)H_(5)OCOO−(9.465 kJ/mol)was lower than that of the AEPCOO−(26.163 kJ/mol),implying that CO_(2)was more likely to be released.Finally,the regeneration energy consumption of the alcohol-regulated absorbentwas estimated to be only 1.92 GJ/ton CO_(2),which had excellent energy-saving potential.
基金supported by the independent research major project of Key Laboratory of Biomass Energy and Materials of Jiangsu Province, China (JSBEM-S-202202)the key project of Science and Technology Plan of Nanping, China (N2022B002)the Open Research Fund of Academy of Advanced Carbon Conversion Technology, Huaqiao University, China
文摘5-Hydroxymethylfurfural(5-HMF)is one of the important bio-based platform compounds,and the catalytic conversion of glucose to 5-HMF is a highly desirable approach that is receiving increasing attention.Herein,we reported the synthesis of lignin-derived carbon supported tin oxides(SnOx/LC)catalyst via a two-step hydrothermal-pyrolytic method using wheat straw alkali lignin as a cost-effective carbon source with high carbon content.The key preparation conditions of the catalyst and its catalytic conditions for the conversion of glucose to 5-HMF were investigated,respectively.Results show that under the preparation conditions of tin tetrachloride dosage of 3.0 mmol and pyrolysis temperature of 500 ℃,the optimized catalyst(3.0-SnOx/LC-500)with a high yield of 63.4%exhibits good catalytic performance of 5-HMF yield of 50.1%and reaction selectivity of 86.0%under the optimum conditions of reaction temperature and time of 190 ℃ and 3 h,initial glucose concentration of 10%(mass),3.0-SnOx/LC-500 dosage of 100 mg in a biphasic solvent system of volume ratio of water to tetrahydrofuran of 1:4.In addition,3.0-SnOx/LC-500 exerts an excellent reusability in a five-cycle experiment.Furthermore,SnOx/LC was characterized in detail using X-ray diffraction patterns(XRD),X-ray photoelectron spectroscopy(XPS),Brunauer-Emmett-Teller(BET),ammonia temperature-programmed-desorption(NH3-TPD),pyridine adsorption infrared spectroscopy(Py-FTIR),scanning electron microscope(SEM)and thermal gravimetric analysis(TGA).Results indicate that Brønsted acid sites and Lewis acid sites coexist on 3.0-SnOx/LC-500,and more Sn^(4+),as well as a proper ratio of weak acidity to medium acidity,are conductive to its catalytic performance in glucose-to-5-HMF reaction.
