Organotemplate-free synthesis of ZSM-5 membrane for pervaporation dehydration of isopropanol

Abstract

ZSM-5 membrane was prepared on tubular macroporous alpha-alumina support using a different synthesis route. The effects of organic template agent and Si/Al ratio of the synthesis gel on morphology, structure, and separation performance of the ZSM-5 membrane used for dehydration of isopropanol were investigated. High water perm-selectivity ZSM-5 membrane with a thickness of about 3.0 um and a low Si/Al ratio of 10.1 was successfully prepared from organotemplate-free synthesis gel with a molar composition of SiO2 : 0.050Al2O3 : 0.21Na2O : NaF : 51.6H2O at 175 degree Celcius for 24 h. The ZSM-5 membrane exhibited high pervaporation performance with a flux of 3.92 kg/(m2.h) and corresponding separation factor of higher than 10,000 for dehydration of 90 wt.% isopropanol/water mixture at 75 degree Celcius.