| Abstract: | Since many years synthetic membranes have been used in reverse osmosis or ultrafiltration for the separation of aqueous mixtures. More recently the separation of gases and vapors by selective membrane permeation has gained significant technical and commercial interest. The recovery of hydrogen from petrochemical purge gases and ammonia production processes or the removal of CO2 from natural gas by selective membrane permeation are today state of the art procedures. The recovery of organic solvents from waste air streams is another very promising application of synthetic membranes. In this paper the main parameters determining the performance of a membrane in gas and vapor separation are described. The requested intrinsic properties of the polymer to be useful as a barrier for a selective gas and vapor transport are discussed. The preparation of appropriate membranes is described. Their performance in practicle applications is illustrated in selected examples. |
