MEMBRANE SEPARATION PROCESS FOR DEHYDRATING A GAS OR VAPOUR OR LIQUID MIXTURE BY PERVAPORATION, VAPOUR PERMEATION OR GAS SEPARATION

摘要

A membrane separation process for dehydrating a gas or vapour or liquid mixture by pervaporation, vapour permeation or gas separation comprises: passing the mixture along the retentate side of a membrane and generating a driving force in order to transport water through the membrane to the permeate side thereof. In order to diminish the permeate volume, to improve the coefficient of performance (COP) and to reduce the acquisition and maintenance costs of the equipment the driving force is generated in that a highly concentrated solution of one or more hygroscopic salts (brine) is situated at the permeate side of the membrane. Preferably the hygroscopic capacity of the brines, expressed as a percentage of water vapour pressure reduction with respect to pure water, has a value of over 50%, preferably of over 80%.