Dehydration of acetic acid by pervaporation through an asymmetric polycarbonate membrane

Dehydration of acetic acid by pervaporation through an asymmetric polycarbonate membrane was investigated. Investigations focused on the effects of feed composition, degree of swelling, and the molar volume of non-solvent additive on the pervaporation performances. The membrane formation systems are discussed in terms of the presence of a nonsolvent in the casting solution, the kinds of coagulation media, and the polymer concentration. The rate of liquid-liquid demixing decreases with increasing alcohol molar Volume of the coagulation medium. The durability of the asymmetric polycarbonate membranes with n-hexanol additive was tested for 3 wt.% aqueous acetic acid solution at 25 degreesC for two months and it was found to be stable. (C) 2001 Elsevier Science Ltd. All rights reserved.