INDUSTRIAL APPLICATION OF VAPOR PERMEATION

Vapour permeation is one of the youngest technically feasible membrane processes. It is an interesting technical alternative to pervaporation. While the same membranes may be used in vapour permeation as in pervaporation, the separation of vaporous solvent mixtures can offer several advantages under certain boundary conditions when compared with pervaporation of liquid feed. The differences and design features are discussed in detail. The straightforward development of vapour permeation from laboratory scale to its first industrial application certainly was only possible with the experience and know-how already gained in the development of pervaporation technology. The concept and operational performance of the first commercial-size vapour permeation plant is described. It is designed for the dehydration of 94% ethanol to a final concentration of 99.9% and is installed at Bruggemann Co. in Heilbronn, Germany. Vapour permeation exhibits not only technical advantages but also favorable economics. This is demonstrated by the results of a cost study in which vapour permeation is compared with other dehydration technologies including pervaporation. A review is also given of other potential industrial applications of vapour permeation which are already technically and economically feasible.