1 INTRODUCTIONIn 1984,GFT Company,the leader in using PVApervaporation membrane for dehydration of alcohol-water mixtures,sets up the first industrial pervapora-tion plant.Now,about 100 industrial pervaporationplants are in operation in the world.For almostall these plants,PVA membranes are equipped andused to dehydrate alcohol.It has been proved that