Separation processes are key to the chemical process industry (CPI) and account for more than 40 percent of CPI energy expenditures. In 1996 more than 74 billion pounds of ethylene and propylene were produced by CPI firms in the U.S., making olefins the largest-volume class of organic chemicals produced. Conventional membrane processesdespite their potential efficiencycannot address this key CPI separation, because membranes and modules cannot maintain selectivity when operating on multicomponent feed streams or withstand exposure to common feed-stream components and operating conditions. The goal of this program is to develop a new class of high-selectivity membranes that effectively and economically separate olefins from paraffins. In particular, we will focus on the separation of propylene from propane. These membranes will consist of an ultrathin hybrid coating material placed on a robust hollow-fiber support and packaged in high-performance solvent- and temperature-resistant membrane modules. The membranes will retain high selectivity when operating on multicomponent feed streams that would swell conventional materials and cause a loss in selectivity. In Phase I, feasibility will be demonstrated by developing coatings for the separation of olefins from paraffins (i.e., propylene from propane). The best coatings developed will be applied to solvent- and temperature-resistant hollow-fiber supports, and their performance demonstrated.
Commercial Applications and Other Benefits as described by the awardee: In addition to olefin/paraffin separations, the hybrid coating materials that are the focus of this program could be used to prepare coatings for a broad range of organic/organic separations important in the CPI.
