Carbon dioxide capture with membranes at an IGCC power plant

Integrated Gasification Combined Cycle (IGCC) power plants are being developed as an economical method of producing electricity from coal while simultaneously capturing carbon dioxide (CO2) for sequestration. In these plants, conventional cold absorption processes are considered the baseline technology to separate CO2 from gasified coal syngas. Separation and sequestration of the CO2 by these methods increases the levelized cost of the electricity (LCOE) produced by about 30%. This paper describes the use of hydrogen-selective and CO2-selective membranes used in various process designs to perform the same separation. The best design, using recently developed membranes, has 40% of the capital cost and uses 50% of the energy of cold absorption. The resulting increase in the LCOE to separate and sequester the CO2 is then about 15%. If higher permeance, and especially more selective, membranes can be developed, the cost of the technology described will be reduced even further.

► Evaluates hydrogen-selective and CO2-selective membranes for IGCC CO2 capture.
► The best membrane design has lower cost and uses 50% of the energy of cold absorption.
► Higher permeance, and especially more selective, membranes will help.