Preparation of Zeolite Membranes and Their Applications

Abstract

Zeolite membranes were classified into four types, that is, self-supporting membrane, supported membrane, oriented self-supporting membrane, and disk membrane. Preparation, properties and applications of these membranes are described. Self-supporting membranes are obtained by using Teflon and cellulose as the substrates, but they are fragile. Supporting membranes can be prepared by both traditional hydrothermal synthesis and solid dry-conversion via vaporphase transport, and they have enough mechanical strength to be used for separation by pervaporation. An oriented self-supporting membrane can be obtained by using mercury surface as the substrate, which is transparent and shows molecular sieving effect for permeation of hexane isomers. A disk membrane can be prepared by heating a shaped mixture of silica or aluminosilicate containing an organic amine in a sealed system and used for a catalytic membrane.