SEPARATION OF WATER-ALCOHOL MIXTURES BY PERVAPORATION THROUGH ASYMMETRIC NYLON 4 MEMBRANE

The dehydration of aqueous alcohol solutions through asymmetric nylon 4 membranes were investigated using pervaporation processes. The forma tion of asymmetric pervaporation membranes are discussed in terms of t he content of the nonsolvent in the casting solution, polymer concentr ation, and compositions of the coagulation medium. The effects of the feed composition, feed temperature, and molar volume of the alcohols o n the pervaporation performances of the asymmetric membranes are discu ssed. A separation factor of 4.72 and a permeation rate of 0.78 kg/m2 h for the asymmetric membrane were obtained. Compared to the conventio nal homogeneous nylon 4 membrane, the asymmetric membrane can effectiv ely overcome the pervaporation performances of the nylon 4 membrane fo r separation of water-alcohol mixtures. (C) 1994 John Wiley & Sons, In c.