Composite membrane used for purifying hydrogen for fuel cells comprises a first material which is permeable for a first substance, and a second material which is selectively permeable for the first substance

摘要

Composite membrane (10) comprises a first material (1) which is permeable for a first substance; and a second material (5) which is selectively permeable for the first substance. The second material is arranged in the first material so that predetermined substances other than the first substance can pass through the membrane via a permeation path which longer than the thickness of the membrane whilst the first substance can pass through the membrane via a permeation path which is the same as the thickness of the membrane. An Independent claim is also included for a process for the production of the composite membrane comprising preparing a melt or solution of a first material (1); mixing in flat particles (5) of a second material; forming a film of the mixture; and stretching the film to such an extent that the flat particles from the second material are directed in the film so that their flat sides are essentially parallel to the surfaces of the film. Preferred Features: The first substance is hydrogen and the other substances are carbon monoxide, carbon dioxide, nitrogen and/or oxygen.