Asymmetric copolyimide membranes fabricated by nonsolvent-induced phase separation for He/CH_(4) and He/N_(2) separation  

作　　者：Ying Li Lu Wang Junyan Xie Yong Dai Xuehong Gu Xuerui Wang 

机构地区：[1]State Key Laboratory of Materials-Oriented Chemical Engineering,College of Chemical Engineering,Nanjing Tech University,Nanjing 211816,China [2]Quzhou Membrane Material Innovation Institute,Quzhou 324000,China

出　　处：《Frontiers of Chemical Science and Engineering》2024年第4期97-106,共10页化学科学与工程前沿（英文版）

基　　金：sponsored by the National Key Research and Development Program of China(Grant No.2021YFC2101203);the National Natural Science Foundation of China(Grant Nos.22178164 and U22B20148);the Jiangsu Provincial Carbon Peak Carbon Neutral Science and Technology Innovation Special Fund(Grant No.BE2022033);the Jiangsu Specially-Appointed Professors Program;the State Key Laboratory of Materials-Oriented Chemical Engineering(Grant No.ZK202002).

摘　　要：Membrane gas separation is considered an energy-saving technique to extract He from natural gas due to no phase change and room temperature operation.However,the membrane performance was strongly limited by the trade-off between permeance and selectivity.Herein,novel 4,4′-(hexafluoroisopropylidene)diphthalic anhydride(6FDA)-2,2′-bis(3-amino-4-hydroxyphenyl)hexafluoropropane(APAF)-5-amino-2-(4-aminobenzene)benzimidazole(BIA)asymmetric membranes with a thickness of 300 nm were successfully prepared by the non-solvent induced phase separation method.The membrane performance was modulated by regulating dope solution compositions(e.g.,tetrahydrofuran and polymer concentration).The ideal He/CH_(4) selectivity was 124 and the optimized He permeance reached 87 GPU,beyond the current upper bound.He/CH_(4) selectivity was 75 and He permeance was 73 GPU for the binary mixture feed containing 0.2 mol%He.The membrane showed good resistance to CO_(2) and C_(2)H_(6),which are the typical impurities in natural gas.The 6FDA-APAF-BIA membranes have good stability(>160 h),which can provide great potential in He extraction from natural gas.

关 键 词：He separation membrane natural gas COPOLYIMIDE 

分 类 号：O63[理学—高分子化学]