Power plant post-combustion carbon dioxide capture: An opportunity for membranes

Abstract Carbon dioxide capture from power plant flue gas and subsequent sequestration is expected to play a key role in mitigating global climate change. Conventional amine technologies being considered for separating CO 2 from flue gas are costly, energy intensive, and if implemented, would result in large increases in the cost of producing electricity. Membranes offer potential as an energy-efficient, low-cost CO 2 capture option. Recently, working with the U.S. Department of Energy (DOE), we have developed membranes with CO 2 permeances of greater than 1000 gpu and a CO 2 /N 2 selectivity of 50 at 30 °C. This permeance is ten times higher than commercial CO 2 membranes and the selectivity is among the highest reported for non-facilitated transport materials. These membranes, in combination with a novel process design that uses incoming combustion air as a sweep gas to generate driving force, could meet DOE CO 2 capture cost targets. Under these conditions, improving membrane permeance is more important than increasing selectivity to further reduce the cost of CO 2 capture from flue gas. Membrane cost and reliability issues will be key to the eventual competitiveness of this technology for flue gas treatment.