Preparation of mordenite membranes for pervaporation of water-ethanol mixtures

A mordenite membrane was synthesized on a ceramic tubular support by seeded hydrothermal synthesis and tested in the dehydration of a water/ethanol mixture by pervaporation. The influence of synthesis conditions (time and gel composition) on the water/ethanol separation factor and water flux was investigated. Typical membranes yielded a water/ethanol separation factor of 150, at a water flux of 0.2 kg/m2·h. The XRD patterns showed that mordenite was the only zeolite material present in the membrane.

The influence of synthesis conditions (synthesis time and level of dilution in the synthesis gel) during the preparation of mordenite membranes has been related to their performance in the dehydration of water/ethanol mixtures by pervaporation. XRD analysis indicates that mordenite was the only present zeolite in the membrane throughout the conditions investigates. Optimum synthesis times (in the range 8–24 h) and water dilution levels exist for this system. The best results were obtained with the following gel composition: H2O:SiO2:Na2O:Al2O3= 80:1:0.38:0.025 Under these synthesis conditions, the membranes Fig. 2. Weight gain (mg of zeolite/g of support) water/ ethanol separation factor and water pervaporation flux as a function of synthesis time and water content in the precursor gel.