The pervaporation process is a relatively new, having common elements, reverse osmosis and gas permeation . The separating liquid mixtures by pervaporation difference in vapor pressure between the feed and the permeate. This difference in vapor pressure can be obtained in different ways: by vacuum applied to the permeate ,the most used laboratory procedure, or by cooling the permeate vapor, causing a partial vacuum, and most common industrially. The membrane destillation use heat streans to provide the evaporations. The pervaporation uses differente methods. I hope it help.