Separation of alcohol/water mixtures by pervaporation through zeolite A membranes

Abstract

Zeolite NaA membranes were prepared from homogeneous solution on macroporous zirconia composite supports in sheet and tube form. Zeolite KA membranes were obtained by ion exchange from the sodium form. The membranes were tested for the removal of water from isopropanol/water mixtures by pervaporation. Feed and permeate compositions and flux were measured for pervaporation at 25 and 70°C. Both the Na and K forms of zeolite A membranes were highly selective, separation factors in excess of 10⁴ being achieved at low concentrations of water in the feed. Membrane performance was not affected by heat treatments to 150°C.