New polymer membranes prepared from polysulfone and polyimide blends for the separation of industrial gas mixtures

摘要

Preparation, testing and examination of gas separation polymer membranes prepared from mixtures of the polysulfone Udel P-1700 and the aromatic polyimide Matrimid 5218.;Polysulfone and polyimide proved to be completely miscible polymers as confirmed from optical microscopy, glass transition temperatures and spectroscopy analyses of the prepared mixtures. The complete miscibility permits the preparation of symmetric and asymmetric blend membranes in any proportion (1-99% wt) of polysulfone and polyimide.;Permeability measurements for various gases of industrial importance (such as carbon dioxide and monoxide, hydrogen, oxygen, nitrogen etc.) through polysulfone-polyimide blend membranes showed significant permeability improvements, compared to pure polyimides, with a minor change in their selectivity. Blend membranes were considerably more resistant to the plasticization phenomenon compared with those of pure polyimides.;Therefore, the use of polysulfone-polyimide polymer blends for the preparation of gas separation membranes offers a new, economic, high performance technical solution for application in the separation of industrial gases, with the typical compositions of gaseous mixtures encountered in the recovery of hydrogen from refinery gases, the separation of hydrogen from ammonia synthesis purge gases, the separation of gaseous products in coal, lignite and other solid fuel gasification processes, the separation of carbon dioxide from the exhaust gases of power generating stations using solid, liquid, gas or biomass as fuels, air separation for the production of nitrogen and/or oxygen enriched streams etc.