This Small Business Innovation Research Phase I project focuses on the separation of olefins from saturated hydrocarbons. Olefins, including ethylene and propylene, are produced in larger quantities than any other organic chemical in the United States. The separation of olefins from saturated hydrocarbons is currently carried out by distillation, which is an extremely energy-intensive process due to the very low relative volatilities of the components. Although polymeric membranes have been applied successfully to a number of gas separations, including nitrogen production from air and hydrogen removal from refinery streams, the selectivities and gas fluxes of such membranes are inadequate for olefin separation from saturated hydrocarbons. Facilitated transport membranes have higher selectivities and gas fluxes than polymeric membranes for olefin/paraffin separation. However, three problems have limited the application of facilitated transport membranes to industrial olefin separation applications: membrane instability, low gas fluxes, and the requirement of a water-saturated feed. Membrane Technology and Research, Inc. (MTR) proposes to develop a new type of solid facilitated transport membrane with high gas fluxes and high selectivities for the separation of olefins from saturated hydrocarbons. The membranes will consist of rubbery, polyether-based polymers that can be doped with a wide range of ionic salts as gas complexing agents. To provide high gas fluxes, the resulting solid polymer electrolyte will be formed into a thin-film composite membrane. Preliminary studies at MTR indicate that polymer electrolyte membranes can show dramatically improved performance over conventional facilitated transport membranes for olefin/paraffin separation and can be used with a dry feed.
