Pervaporation and Vapor Permeation Tutorial: Membrane Processes for the Selective Separation of Liquid and Vapor Mixtures
Pervaporation and vapor permeation are membrane based processes proposed as alternatives to conventional separation technologies. Applications range from organic solvent removal from water, ethanol, or butanol recovery from fermentation broths, solvent/biofuel dehydration to meet dryness specifications, and organic organic separations such as the removal of sulfur compounds from gasoline. Unlike membrane filtration processes, which rely on an applied liquid pressure gradient and size sieving to accomplish a separation, pervaporation and vapor permeation separate compounds based on a chemical activity driving force and the sorption and diffusion of the compounds through the membrane. These properties enable the separation of even miscible liquid mixtures.