High Permeance Hybrid Membranes for CO2 Separation

The ability to effectively remove carbon dioxide (CO2) from gas mixtures offers great potential to increase the energy efficiency of fossil fuel production, power generation, chemical production, and industrial gas purification. CO2 is present in a wide variety of gas mixtures, arising from both aerobic and anaerobic respiration processes, as well as the anthropogenic combustion of fossil fuels. In addition to being a potent greenhouse gas pollutant, the presence of CO2 in fuel streams reduces the specific heating value of the fuel, while in chemical process streams; CO2 may adversely affect usable product yield, product selectivity and process efficiency. A composite CO2 selective membrane with high permeability will be developed in the proposed program in order to separate out CO2 emissions from coal gasification plants as well as aid in the upgrading of natural gas. The proposed membrane will work under broader operating conditions and be ten times more permeable to CO2 than existing commercial CO2 separation membranes, thereby enabling more efficient process integration and facilitating new process intensification designs. The composite membrane was synthesized and characterized in the Phase I effort. High CO2 permeability and CO2/H2 and CO2/CH4 selectivities were measured at temperatures up to 240C and pressures up to 310 psia. The Phase II program initially focuses on refining the synthesis of the membrane and increasing CO2 permeability and selectivities. The CO2 flux of the membrane will also be improved and a subscale membrane module will be fabricated and demonstrated. Commercial Applications and Other Benefits: Application of the proposed technology within coal gasification plants, natural gas plants, and industrial gas production facilities offers the potential for greater process efficiencies and reduced CO2 emissions.