离子热法合成CHA型分子筛膜及其脱盐应用  

Ionothermal Synthesis of CHA-Type Zeolite Membrane for Desalination

作　　者：张慧智 甘来 刘妮 黄欣悦 胡娜 陈祥树 ZHANG Huizhi;GAN Lai;LIU Ni;HUANG Xinyue;HU Na;CHEN Xiangshu(Institute of Advanced Materials,State-Province Joint Engineering Laboratory of Zeolite Membrane Materials,College of Chemistry and Chemical Engineering,Jiangxi Normal University,Nanchang 330022,China)

机构地区：[1]江西师范大学先进材料研究院,分子筛膜材料国家地方联合工程实验室,江西师范大学化学化工学院,南昌330022

出　　处：《硅酸盐学报》2022年第5期1375-1384,共10页Journal of The Chinese Ceramic Society

基　　金：国家自然科学基金(21868013,21868012,21968009)。

摘　　要：通过合成较高骨架硅铝比的CHA型分子筛膜可实现提高膜层稳定性和分离性能。采用咪唑类离子液体合成出纯相的CHA型分子筛膜,离子液体不仅作为新型结构导向剂,还提高晶体骨架Si/Al比,同时离子液体回收使用3次后仍能合成出高结晶度CHA型晶体。在最佳合成条件下,通过含溴化1-丁基-3-甲基咪唑([Bmim]Br)的合成溶胶中在莫来石管状支撑体上获得连续的CHA型分子筛膜层,该膜在75℃、3.5%(质量分数)氯化钠溶液中渗透水通量为6.3 kg/(m^(2)·h),截留率高达100%。考察了操作温度和料液浓度对膜渗透汽化脱盐性能影响。当操作温度升高至90℃时,膜水通量急剧提高到10.3 kg/(m^(2)·h),甚至在10%高浓度氯化钠溶液中以及在3.5%氯化钠溶液中连续测试3.5 d,膜均表现出优异的脱盐性能。Zeolite chabazite(CHA)membranes with a higher Si/Al mole ratio in the zeolite framework were prepared to improve their stability and separation performance.Pure zeolite CHA membranes were synthesized with imidazolium-based ionic liquids(ILs)as a structure-directing agent,which could improve the Si/Al ratio in the framework.ILs could be used repetitively at least 3 times for the synthesis of high-crystallinity zeolites.Under the optimized synthetic conditions,a continued zeolite CHA membrane obtained from an initial gel containing 1-buthyl-3-methylimidazolium bromide([Bmim]Br)on the mullite tubular supports has a high water flux of 6.3 kg/(m^(2)·h)with a high ion rejection(100%)for pervaporation(PV)separation of 3.5%(in mass fraction)NaCl aqueous solution at 75℃.The effects of temperature and feed concentration on the desalination performance of ILs-CHA membranes were also investigated.The water flux increases to 10.3 kg/(m^(2)·h),and their salt rejections are 100%when the operating PV temperature increases at 90℃.Zeolite CHA membranes prepared have the superior separation performance even for desalination of 10%NaCl aqueous solution.Furthermore,the ILs-CHA zeolite membrane has a stable separation performance with a stable water flux as well as a high salt rejection in 3.5%NaCl aqueous solution at 75℃for 3.5 d.

关 键 词：CHA型分子筛膜 离子液体 脱盐 渗透汽化 水热稳定 

分 类 号：TQ028.8[化学工程]