Polysulfone-Co-Poly(ethylene oxide) Random Copolymer Membranes for CO2 Separation

Abstract

Membrane-based gas separation is actually developing industrial membrane separation technologies, and the market size and number of applications served are expanding because it offers a number of advantages in terms of energy and capital cost. Current membrane-based gas processes and potential applications include hydrogen separation and recovery from ammonia purge gas, refinery, and syngas stream in the petrochemical industry. Other applications include carbon dioxide separation from flue gas in power plants, natural gas processing, and landfill gas upgrading. Here we have developed new polysulfone membranes including poly(ethylene oxide) (PEO) segments for selective CO2 separation. Generally, polysulfone (PSf) is a glassy polymer that has been extensively used for membrane applications such as gas separation, ultrafiltration and support membranes for nanofiltration and reverse osmosis. It is well-known that PEO with ether oxygen units appears to provide excellent CO2 separation and permeation properties, by enhancing CO2 sorption capability in PEO segments relative to other small gas molecules such as hydrogen and nitrogen. In this work, polysulfone-co-poly(ethylene oxide) random copolymer membranes were prepared by varying molar ratio of PEO segments and molecular weight of PEG segments, and their gas separation performances were deeply discussed in terms of correlation between CO2 permeability and CO2/H2, CO2/CH4, and CO2/N2 selectivity, respectively.