Pervaporation and vapor permeation are membrane-based processes which have been proposed as alternatives to conventional separation technologies. Applications range from organic solvent removal from water, ethanol or butanol recovery from dilute fermentation broths, solvent/biofuel dehydration to meet dryness specification, 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 & diffusion of the compounds through the membrane. These properties enable the separation of even miscible liquid mixtures such as ethanol-water solutions.
In this presentation, we will discuss the following:
Process fundamentals
Solution-diffusion mechanism
Mass transfer
Energy issues
State-of-the-science and future trends
Membranes (hydrophobic and/or hydrophilic,)
Modules
Processes
Pervaporation-Dephlegmation
Hybrid Processes
Integration of Pervaporation with Fermentation Systems