Current and future trends in polymer membrane-based gas separation technology: A comprehensive review

Polymeric gas separation membranes have become a competent technology over the past few decades. This review focuses on the broad classifications of membrane materials and the criteria for the selection of membrane materials, describes the various synthesis routes adopted for membrane fabrication, and explains various gas transport mechanisms. A comparison of membrane-based separation technology with other conventional technologies has also been made. The review also discusses the current polymers used for gas separations, current commercially viable membrane-based gas separation processes, and various limitations associated with the development of membrane material and separation processes. Further, various new classes of membranes developed for gas separations, including thermally rearranged polymers, polymers of intrinsic microporosity, room temperature ionic liquids, perfluoro polymers, and mixed matrix membranes, that has high separation performance has also been discussed. Some of the emerging membrane-based gas separations are also reviewed.