COMPARISON OF THE SEPARATION OF MIXTURES BY VAPOR PERMEATION AND BY PERVAPORATION USING PVA COMPOSITE MEMBRANES .1. BINARY ALCOHOL WATER-SYSTEMS

Results of vapor permeation experiments with binary mixtures of methanol-water, ethanol-water, 1-propanol-water and 2-propanol-water performed under various operating conditions are reported. The data are compared to those obtained applying pervaporation. In particular the effect of feed pressure and feed composition, permeate pressure and membrane temperature on transmembrane fluxes and separation characteristics has been investigated for the PVA-PAN composite membrane manufactured by GFT mbH (Neunkirchen-Heinitz, Germany). In general, for a specific mixture the separation factors are significantly larger but the transmembrane fluxes are smaller in the case of vapor permeation compared with pervaporation.