The synthesis of propylene carbonate(PC)from CO_(2) and propylene oxide(PO)is a typical gas-liquid biphasic system,where gas-liquid mass transfer efficiency significantly influences CO_(2) cycloaddition reactions.Here...The synthesis of propylene carbonate(PC)from CO_(2) and propylene oxide(PO)is a typical gas-liquid biphasic system,where gas-liquid mass transfer efficiency significantly influences CO_(2) cycloaddition reactions.Here,we proposed a microchannel reaction system for the CO_(2) cycloaddition reaction catalyzed by ionic liquid within an aqueous environment.The effect of liquid flow rate,temperature and residence time on gas-liquid flow pattern,catalytic performance and mass transfer were systematically investigated.The results revealed that the PC generation rate reached 560.11 mmol·ml^(−1)·h^(−1)at a 50 cm of flow distance under reaction conditions of 105℃,2.5 MPa,QG=176 ml·min^(−1) and QL=0.3 ml·min^(−1).Variations in mass transfer rate and reaction rate at different flow distances were experimentally studied.The reaction efficiency gradually decreased with increasing flow distance,which were attributed to the reduction of mass transfer caused by decreasing bubble velocity.Optimizing bubble velocity at an appropriate position enhanced reaction efficiency by improving mass transfer,achieving a 97.7%PC yield within 2.85 min.Furthermore,a kinetic model coupling intrinsic kinetics with gas-liquid mass transfer was developed for CO_(2) cycloaddition reaction.The kinetic model was applied to predict PC reaction rates in microchannel reactors at various temperatures and liquid flow rates,achieving an average relative error of 9.6%.展开更多
使用Anton Paar DMA 4500U型振动管密度计,测量碳酸二甲酯+碳酸二乙酯和碳酸二甲酯+碳酸甲乙酯两个混合体系在293.15~313.15K温度区间和常压下,全浓度范围的密度;基于所测得的密度数据,计算这两个混合体系的超额摩尔体积。用Redlich-Kis...使用Anton Paar DMA 4500U型振动管密度计,测量碳酸二甲酯+碳酸二乙酯和碳酸二甲酯+碳酸甲乙酯两个混合体系在293.15~313.15K温度区间和常压下,全浓度范围的密度;基于所测得的密度数据,计算这两个混合体系的超额摩尔体积。用Redlich-Kister方程对超额体积和摩尔分数关系进行关联检验。结果表明,不同温度下超额摩尔体积随组分摩尔分率升高,碳酸二甲酯+碳酸二乙酯体系超额摩尔体积均为正偏差,碳酸二甲酯+碳酸甲乙酯呈先正偏差后负偏差的趋势。这些现象是由这两个混合体系中偶极-偶极相互作用、分子间作用力、以及溶剂化效应等多种因素的综合作用导致的。通过Prigogine-Flory-Patterson预测理论对混合物的超额摩尔体积数据进行分析。展开更多
基金supported by the National Key Projects for Fundamental Research and development of China(2020YFA0710202)the China Postdoctoral Science Foundation(2024M761567)Shandong Postdoctoral Science Foundation(SDCX-ZG-202400271).
文摘The synthesis of propylene carbonate(PC)from CO_(2) and propylene oxide(PO)is a typical gas-liquid biphasic system,where gas-liquid mass transfer efficiency significantly influences CO_(2) cycloaddition reactions.Here,we proposed a microchannel reaction system for the CO_(2) cycloaddition reaction catalyzed by ionic liquid within an aqueous environment.The effect of liquid flow rate,temperature and residence time on gas-liquid flow pattern,catalytic performance and mass transfer were systematically investigated.The results revealed that the PC generation rate reached 560.11 mmol·ml^(−1)·h^(−1)at a 50 cm of flow distance under reaction conditions of 105℃,2.5 MPa,QG=176 ml·min^(−1) and QL=0.3 ml·min^(−1).Variations in mass transfer rate and reaction rate at different flow distances were experimentally studied.The reaction efficiency gradually decreased with increasing flow distance,which were attributed to the reduction of mass transfer caused by decreasing bubble velocity.Optimizing bubble velocity at an appropriate position enhanced reaction efficiency by improving mass transfer,achieving a 97.7%PC yield within 2.85 min.Furthermore,a kinetic model coupling intrinsic kinetics with gas-liquid mass transfer was developed for CO_(2) cycloaddition reaction.The kinetic model was applied to predict PC reaction rates in microchannel reactors at various temperatures and liquid flow rates,achieving an average relative error of 9.6%.
文摘使用Anton Paar DMA 4500U型振动管密度计,测量碳酸二甲酯+碳酸二乙酯和碳酸二甲酯+碳酸甲乙酯两个混合体系在293.15~313.15K温度区间和常压下,全浓度范围的密度;基于所测得的密度数据,计算这两个混合体系的超额摩尔体积。用Redlich-Kister方程对超额体积和摩尔分数关系进行关联检验。结果表明,不同温度下超额摩尔体积随组分摩尔分率升高,碳酸二甲酯+碳酸二乙酯体系超额摩尔体积均为正偏差,碳酸二甲酯+碳酸甲乙酯呈先正偏差后负偏差的趋势。这些现象是由这两个混合体系中偶极-偶极相互作用、分子间作用力、以及溶剂化效应等多种因素的综合作用导致的。通过Prigogine-Flory-Patterson预测理论对混合物的超额摩尔体积数据进行分析。
