| Итог: | The commercialization of membrane systems for gas separation has become a reality in recent years. The asymmetric structure of these membranes provides high flux and selectivity in the same manner as has been realized in reverseosmosis. While similar principles apply in both processes, the parameters affecting separation one is concerned with partial pressure and the pressure ratio of the feed gas to the permeate gas. As a process, membrane gas separation competes with adsorption, absorption and distillation technologies. In some cases, however, a combination of membranes with these processes offers economic or technical advantages (1,2). In the following paragraphs several applications of membranes will be discussed in comparison with these conventionsl methods. In addition, a comparison of a cellulose acetate membrane and a dimethyl silicone membrane for nitrogen enrichment will be presented to illustrate how membrane performance affects economics.
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