Effect of fabrication and process parameters on the morphology and performance of a PAN-based zeolite-filled pervaporation membrane

The aim of this study is to develop a novel pervaporation membrane for dehydration of azeotropic ethanol-water mixture and to investigate the effect of membrane preparation and process parameters on the membrane performance. Zeolites (3A, 4A and 13X) are added as fillers to the base polymer poly [acrylonitrile] (PAN). It is observed that the volatility of the casting solvent and the annealing temperature strongly affect the performance and morphology of the manufactured membranes. Scanning electron micrographs (SEM) shows that with the membrane preparation procedure adopted three layers are formed. These are zeolite-free polymer layer, zeolite-filled polymer layer and a skin layer. The effect on the membrane performance of the feed composition, permeate side pressure, zeolite type and content are studied. It is concluded that the zeolite content determines the membrane morphology and the dominant layer controlling the transport mechanism. At about 32 wt.% zeolite, flux is increased about nine-fold with a loss of selectivity about seven-fold relative to homogeneous PAN membranes. (C) 2003 Elsevier B.V. All rights reserved.