含有MCM-41分子筛的混合基质复合膜用于CO2分离  

Novel mixed matrix composite membranes containing MCM-41 for CO_2 separation

作　　者：何玉鹏[1] 王志[1] 乔志华[1] 远双杰[2] 王纪孝[1] 

机构地区：[1]天津大学化工学院化学工程研究所,天津化学化工协同创新中心,化学工程联合国家重点实验室(天津大学),天津市膜科学与海水淡化技术重点实验室,天津300072 [2]中国石油天然气管道工程有限公司,河北廊坊065000

出　　处：《化工学报》2015年第10期3979-3990,共12页CIESC Journal

基　　金：国家自然科学基金项目(21436009);国家高技术研究发展计划项目(2012AA03A611)~~

摘　　要：为了提高CO2分离膜的性能,将接枝了氨基的MCM-41分子筛(MCM-NH2)添加到聚乙烯基胺(PVAm)水溶液中配制涂膜液,并将PVAm-MCM-NH2涂膜液涂覆到聚砜(PSf)超滤膜上制备PVAm-MCM-NH2/PSf混合基质复合膜。复合膜分离层较薄,有利于CO2渗透速率的提高。接枝的胺基提高了分子筛与聚合物的相容性和膜内胺基含量,有利于膜渗透选择性能的提高。使用CO2/N2混合气(15%CO2+85%N2,体积分数)考察了不同MCM-NH2添加量的PVAm-MCM-NH2/PSf膜的渗透选择性能。当涂膜液中mMCM-NH2/mPVAm为0.2、湿涂层厚度为50μm,测试温度为22℃、进料气压力为0.11 MPa时,膜的CO2渗透速率可达4.66×10-7 mol·m-2·s-1·Pa-1,CO2/N2分离因子可达150。较高的CO2/N2分离性能表明PVAm-MCM-NH2/PSf膜在烟道气碳捕集领域具有良好的应用前景。此外,考察了湿涂层厚度、热处理、添加小分子胺等条件对膜渗透选择性能的影响。To improve the performance of CO2 separation membrane, MCM-41 modified by amines （MCM-NH2） was filled into polyvinylamine （PVAm） aqueous solution to fabricate PVAm-MCM-NH2 coating solutions. PVAm-MCM-NH2/polysulfone （PSf） mixed matrix composite membranes were prepared by coating PVAm-MCM-NH2 solutions on PSf ultrafiltration membranes. The separation layer of the composite membrane was very thin, which benefited the improvement of CO2 permeance. The amine groups grafted to MCM-41 facilitated the transport of CO2 through reversible reaction and simultaneously improved the filler-polymer interface compatibility. The separation performance of PVAm-MCM-NH2/PSf membranes with different MCM-NH2 content was tested using CO2/N2 mixed gas （15% （vol） CO2 ＋ 85%（vol） N2）. WhenmMCM-NH2/mPVAm in the coating solution was 0.2 at testing temperature of 22℃ and feed gas pressure of 0.11 MPa, the composite membrane exhibited a CO2 permeance of 4.6×10^-7 mol·m^-2·s^-1·Pa^-1 and a CO2/N2 selectivity of 150. The high-performance PVAm-MCM-NH2/PSf membrane showed promising applications in CO2 capture from flue gas. Moreover, the effects of the wet coating thickness, the heat treatment and the introduction of the small molecule amines on the separation performance of PVAm-MCM-NH2/PSf membrane were investigated. The results indicated that the increase of wet coating thickness （from 50μm to 100μm） with heat treatment under 80℃ or the introduction of ethanediamine would lead to the improvement of the pressure stability, but the loss of CO2/N2 separation performance under low pressures.

关 键 词：混合基质膜 复合膜 分子筛 MCM-41 烟道气 二氧化碳捕集 

分 类 号：TQ028.8[化学工程]