Mordenite and ZSM-5 hydrophilic tubular membranes for the separation of gas phase-mixtures

Water was selectively separated from water/He, water/HC and water/HC/He mix tures (HC being methane, propane or n-butane) using mordenite/ZSM-5/chabazi te and ZSM-5 membranes. The membranes were prepared on both alumina and sta inless steel tubular porous supports by in situ liquid phase hydrothermal s ynthesis. Water permeated faster because its preferential adsorption on the pores of the hydrophilic zeolite membranes; furthermore, capillary condens ation in microporous defects between zeolite crystals is also possible unde r the experimental conditions used. The influence of the nature of the hydr ocarbon in the mixtures and of the operating conditions (temperature and fe ed composition) on the separation performance of the zeolite membranes was analyzed. (C) 2000 Elsevier Science B.V. All rights reserved.