Extraction equilibria of valeric acid using (Alamine 336/diluent) and conventional solvent systems. Modeling considerations

Asymmetric poly(vinyl alcohol) (PVA) membranes crosslinked with glutaraldehyde (GA) were prepared by phase inversion technique for pervaporation dehydration of isopropanol (IPA). The crosslinking solutions contain sodium sulfate, sulfuric acid and different contents of GA, wherein sulfuric acid serves as a catalyst. The effects of three variables involved in the membrane preparation, including PVA molecular weight, PVA concentration and GA concentration on pervaporation characteristics were investigated. The results showed that the permeation flux decreases with the increase of these three factors, whereas the selectivity has an opposite trend. The influence of feed IPA concentration and temperature on pervaporation performances was also studied to find optimum operating conditions.