A STUDY OF THE PERVAPORATION OF ISOPROPYL-ALCOHOL WATER MIXTURES BY CELLULOSE-ACETATE MEMBRANES

The preferential sorption characteristics for the system isopropyl alcohol-water-cellulose acetate from both liquid and vapor phases have been studied. Liquid and gas chromatographic methods were used for the study. It was found that isopropyl alcohol was preferentially adsorbed from the liquid phase while water was preferentially adsorbed from the vapor phase. The permeations of pure isopropyl alcohol and pure water through cellulose acetate membranes by pervaporation have been studied under various downstream pressures. The experimental results were further analyzed by using a transport theory developed on the basis of the pore model. The separation of the mixture of isopropyl alcohol and water has also been attempted by pervaporation using cellulose acetate membranes. The transport theory developed for the prediction of the permeate vapor composition and the permeation rate on the basis of the pore model was used for the analysis of the experimental data. It has been found that a set of equations based on the pore flow mechanism fits the experimental data reasonably well. © 1990.