ZSM-5/NaY型复合分子筛膜的制备及其渗透汽化性能研究

Preparation of ZSM-5/NaY composite molecular sieve membrane and its pervaporation performance

采用水热合成法在n(SiO2)∶n(Al2O3)∶n(Na2O)∶n(H2O)为25∶1∶22∶600的合成液体系中合成高性能的ZSM-5/NaY型复合分子筛膜,考察了陈化时间、合成液中水的摩尔分数、合成时间以及合成温度对膜的渗透汽化分离性能的影响,同时,考察了ZSM-5/NaY型复合分子筛膜的稳定性。利用SEM和XRD对膜的形态结构进行表征。结果表明,在合成液陈化18 h后,在105℃下晶化6 h,可成功制备出连续致密的ZSM-5/NaY型复合分子筛膜;在75℃下分离90%的异丙醇/水体系,渗透侧水质量分数可以达到99.15%以上,渗透通量保持在2.12 kg/(m^2·h)以上,并且具有良好的重复性。

High performance ZSM-5/NaY composite molecular sieve membrane is synthesized through hydrothermal synthesis method in a synthesis solution system with a molar ratio of SiO2∶Al2O3∶Na2O∶H2O being 25∶1∶22∶600.The effects of aging time,molar fraction of water in synthesis solution,synthesis time and synthesis temperature on the pervaporation separation performance of the membrane are discussed,and the stability of the synthesized membrane is investigated.Morphological structure of the membrane is characterized by SEM and XRD methods.The experimental results show that a continuous dense ZSM-5/NaY composite molecular sieve membrane can be successfully prepared through 6 h of crystallization at 105℃after the synthesis solution has been aged for 18 h.As the synthesized membrane is used to separate 90wt%isopropanol/water system at 75℃,the water content at the permeate side can exceed 99.15wt%,and the permeate flux remains above 2.12 kg·m^-2·h-1.The experiments have good repeatability.