Abstract Only a few years ago, when highly selective poly(vinyl alcohol) composite membranes became available, the pervaporation process for dehydration of alcohol had only been proven on a laboratory scale. For commercial application a suitable membrane module had to be developed. This paper describes the development of the LURGI pervaporator consisting of a special plate -type membrane module and an integrated permeate condenser combined in one compact unit. Furthermore, the specific design criteria as well as the operational performance of the first commercial-scale pervaporation plant for dehydration of ethanol are presented. This pervaporation demonstration unit, installed in an alcohol production plant, is in continuous operation for one year now. It operates in parallel to a conventional azeotrope entrainer distillation unit, which allows a direct comparison of technical and economic aspects of both dehydration processes.