Preparation of poly(vinyl alcohol)-sodium alginate hollow-fiber composite membranes and pervaporation dehydration characterization of aqueous alcohol mixtures

A hollow-fiber composite membrane, poly(vinyl alcohol) (PVA)-sodium alginate (SA) blend, supported by a polysulfone (PS) hollow-fiber ultrafiltration membrane, was prepared for pervaporation dehydration from isoproanol, n-butanol, tert-butanol and ethanol aqueous solutions. The compatibility of PVA–SA was characterized by FTIR and SEM; the mechanism of the cross-linking reaction is discussed. The results of pervaporation showed that high selectivity and promising permeability were obtained at a 4:1 ratio of the composition of the blended membrane crosslinked with 1.5 wt% maleic acid for 8 h. With alcohol concentration at 90 wt% in the feed at 45°C, the separation factors and permeation fluxes were 1727, 414 g/m2.h; 606, 585 g/m2.h; 725, 370 g/m2.h; and 384, 384 g/m2.h for four alcohol aqueous solutions through the blended membranes.