Membrane performance requirements for carbon dioxide capture using hydrogen-selective membranes in integrated gasification combined cycle (IGCC) power plants

Abstract Precombustion CO 2 capture is an important option for the management of greenhouse gas emissions from power generation, because the higher concentrations can lead to improved separation economics. Membranes can provide a significant boost in the performance by separating CO 2 at high temperature and at high pressure, provided they are properly integrated into a power plant. In this study, membrane performance targets were derived for CO 2 capture using H 2 -selective membranes in integrated gasification combined cycle (IGCC) power plant systems. Three key differences were found relative to plants configured for the production of industrial-grade H 2 . First, the H 2 /CO 2 selectivity requirement is lower when the permeate is combusted in a gas turbine, as opposed to purified for industrial use. Second, the membrane is subject to additional selectivity requirements. For example, CO 2 product purity specs impose a H 2 /N 2 selectivity requirement. Third, the plant design must account for the energy associated with unshifted CO, CH 4 and other fuel components that are not separated by the membrane. In contrast to H 2 production systems where the high H 2 /CO 2 selectivity requirement favors ultra-high selectivity metal-based membranes, the requirements for IGCC indicate a wider range of materials, including ceramic, zeolite, and polymeric membranes, should be considered.