molecular sieve question in Airplanes - Ethanol Tuning Posted March 22, 2008 · Report reply Just dogpiled molecular sieves and found this---kinda interesting. Vaperma Siftek? hollow-fiber polymeric membrane enables the dewatering of a 40:60 ethanol to water vapor mixture into a 99+% w/w fuel-grade ethanol product. There is no need to rectify the ethanol/water blend after evaporation. By replacing the rectifier and the molecular sieve used in a conventional ethanol plant, energy savings as high as 40 % are possible with the innovative membrane permeation process developed by Vaperma. This is equivalent to a cost reduction of 6.4 ?/Gal (1,7?/L). Vaperma has teamed up with Canada's largest producer of ethanol, Greenfield Ethanol (GFE- previously Commercial Alcohols Inc.), to prove its Siftek? membrane technology prior to its industrial scale commercialization, projected for 2008. In addition, Vaperma has teamed up with Dedini, the largest ethanol equipment provider in Brazil, to promote its technology.