High-Performance Plasticization-Resistant Membranes for Natural Gas Separations

72079-Approximately 20% of U.S. natural gas reserves are subquality due to a high carbon dioxide content. Membrane separation is an attractive technology to remove this carbon dioxide; however, membranes with higher flux and selectivity are required to improve the economics and reliability of the technology. This project will develop a new type of fluorinated polymer membrane that has exceptional permeation characteristics and is resistant to plasticization and attack by higher hydrocarbons, aromatics, and other liquids. In Phase I, thin-film composite membranes were made from a series of glassy polymers that were chemically modified using a novel fluorination process. The best membranes had carbon dioxide/methane selectivities of 35 to 40 and carbon dioxide permeances of 70 GPU when tested at 500 to 1,000 psi with hydrocarbon-rich gas. In Phase II, these membranes will be scaled up to industrial scale and evaluated in pilot-scale systems at natural gas processing plants. Commercial Applications and Other Benefits as described by awardee: Currently, membrane separation has only a 4-6% share of the total carbon dioxide/natural gas separation market. Improved membranes should lower the cost of membrane processes and substantially increase the membrane market share.