Dehydration of ethanol and isopropanol using tubular type cellulose acetate membrane with ceramic support in pervaporation process

Abstract

A tubular type membrane was prepared for the dehydration of ethanol and isopropanol in pervaporation. The membrane was formed either on the inner or on the outer surface of a porous ceramic support with cellulose acetate by a dip-coating and rotation-drying technique. The state of the coating surface was investigated by SEM photography. The overall mass transfer coefficient of water, k(wo), was determined at three temperatures as a function of feed flow rate. In a membrane coated on the inner surface, the dependence of k(wo) on the feed flow rate was in good agreement with the Leveque correlation: k(wo) proportional to Re-1/3. The activation energy of water in ethanol dehydration was hardly affected by the feed flow rate. As feed temperature increases, the mass transfer coefficients of water in ethanol and isopropanol dehydration increase. The ceramic support coated with cellulose acetate can be recovered by the solvent and sonication treatment.