PERVAPORATIVE DEHYDRATION OF ORGANIC-SOLVENTS

Pervaporative separation of acetone/water and isopropanol (IPA)/water systems has been studied in the water-lean range of composition of the feed mixtures. Poly(vinyl alcohol) (PVA) membranes crosslinked with c itric acid, adipic acid, maleic acid, glutaraldehyde, and glyoxal were used for this purpose. The sorption characteristics of all the membra nes indicate that these membranes have a good sorption selectivity for water in view of the hydrophilic nature of PVA. The type of crosslink er used for crosslinking has been shown to have an important bearing o n the permeation characteristics of the membranes. Thus, the trifuncti onal citric acid yields the highest selectivity but lowest flux. A com parison of the productive capacities of the various membranes indicate s that the glutaraldehyde crosslinked membrane has the maximum product ive capacity for IPA dehydration whereas maleic acid crosslinked membr ane yields the highest productive capacity for acetone dehydration.