Future Directions of Membrane Gas Separation Technology

During the past 20 years, sales of membrane gas separation equipment have grown to become a $150 million/year business. More than 90% of this business involves the separation of noncondensable gases: nitrogen from air; carbon dioxide from methane; and hydrogen from nitrogen, argon, or methane. However, a much larger potential market for membrane gas separation lies in separating mixtures containing condensable gases such as the C3+ hydrocarbons from methane or hydrogen, propylene from propane, and n-butane from isobutane. These applications require the development of new membranes and processes. In this review, the existing gas separation applications are surveyed, and the expected growth of these and…