New Membrane Structure for Gas Separations

Natural gas offers cost and environmental benefits over other conventional energy sources and decreases our dependence on oil imports. However, many sources of natural gas also contain large amounts of non-hydrocarbon gases, which make them uneconomical to market. Removal of these non-hydrocarbon impurities, in order to raise low quality raw gas to pipeline quality, could have significant economic and environmental benefits. However, many of these impurities ¿ carbon dioxide, hydrogen sulfide, water, heavy components, and hydrocarbon condensates ¿ can be deleterious to gas separation membranes. In addition to fouling the membrane and reducing gas transport, these impurities also can change the membrane¿s permeation characteristics. For example, condensation of liquids on the membrane surface can wash away some types of membrane coatings. Also, a chemical attack can weaken the polymer membrane and cause mechanical failure. This project will develop functional polymers to enhance membrane flux and selectivity. The approach will combine (1) existing copolymers (with excellent chemical and thermal resistance, plus high gas flux) and (2) new functional groups at the monomer level, which will improve membrane fouling resistance, and increase selectivity and flux. Commercial Applications and other Benefits as described by the awardee: Membranes having thermal stability, chemical resistance, high flux, fouling resistance, and high separation should enable the treatment of a number of natural gas sources that might otherwise be uneconomical to market. While the focus of this proposal is natural gas improvement, the technology also should have significant value in methane/carbon dioxide separation, in enhanced oil recovery operations, and for CO2 removal from hydrocarbon liquids.