Development of methanol selective membranes for separation of methanol-methyl tertiary butyl ether mixtures by pervaporation

Several copolymers of acrylonitrile (AN) were synthesized. Methanol selecti ve membranes were prepared from these copolymers of AN. The other monomers in the copolymers were selected on the basis of their solubility parameter values relative to those of methanol. These were hydroxyethyl methacrylate, methacrylic acid, and vinyl pyrrolidone. Thus, pervaporative separation of methanol from its mixture with methyl tertiary butyl ether over the entire concentration range of 0-100% methanol was studied using these copolymer m embranes of AN. For each copolymer of AN three different membranes with dif ferent copolymer compositions were prepared. Copolymers of AN with hydroxye thyl methacrylate and methacrylic acid showed high selectivity and moderate flux for methanol (2561, 773, 0.057, and 0.045 kg/m(2) h, respectively, wi th a membrane of 50-mu m thickness for a feed mixture containing 5% methano l at 30 degrees C). A copolymer of AN with vinyl pyrrolidone showed compara ble flux, but methanol selectivity of this membrane was poor. (C) 1999 John Wiley & Sons, Inc.