Abstract
The method of pervaporation combines, in a single unit operation, selective membrane permeation of species with their subsequent evaporation – i.e., it concentrates as it separates. Pervaporation is being seriously considered for wider commercial applications as a means of separating volatile liquids. Laboratory experiments on pervaporation with liquid mixtures started more than seventy years ago.1 Binning and coworkers2 first identified its commercial potential. Since then numerous laboratory investigations have been directed to separating a variety of liquid mixtures. In recent times many pervaporation membranes have been developed and tested in the laboratory. Commercial success has also been attained in several cases such as drying of aqueous ethanol.3 More than 90 industrial solvent dehydration units using pervaporation process have been installed worldwide.4