Hollow Fiber Membranes for Gas Separation

This chapter discusses the application of hollow fiber (HF) membranes in the field of gas separation. HF allow to minimize energy cost, equipment size, waste production, and, in some cases, to convert by-products into new products with innovative value in the light of an increasingly necessary circular economy. Their main applications in gas separation are hydrogen recovery, oxygen-enriched air production, biogas upgrading, natural gas treatment, and post-combustion carbon capture from flue gas. HF membranes can be used to separate air for yielding either oxygen-or nitrogen-enriched streams or the pure gases as the final products. Biogas upgrading is a strongly emerging application field of polymeric gas separation membranes that has already reached a large-scale industrial application for the separation of biogas from organic waste, while thousands of smaller units are available worldwide. Helium recovery from natural gas by means of HF membrane separation is a valid alternative to the traditional cryogenic distillation.