Pervaporative permeations of homologous series of alcohol aqueous mixtures through a hydrophilic membrane

Abstract

The permeation behaviors of permeants were investigated in the pervaporation of a homologous series of alcohol aqueous mixtures through a hydrophilic poly(vinyl alcohol) (PVA). The PVA membrane was crosslinked with glutaraldehyde. A homologous series of alcohols used in this study were methanol, ethanol, 1-propanol, and 1-butanol. The pervaporation experiments were carried out with feed having 70–97 wt % of alcohol contents and at various feed temperatures. In a high alcohol content above 92 wt %, the permeation rate was increased in the order of the interaction strength between alcohol and water in the feed. However, in a low alcohol content below 90 wt %, the tendency of the permeation rate was found to be the opposite, indicating that the interactions between permeant constituents play an important role in determining the permeation and separation of the mixtures. These observations were discussed in terms of changes in the interaction between the permeant/permeant or the permeant/membrane in varying feed compositions and feed temperatures. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 79: 703–713, 2001