(143m) Recent Advances in Carbon Dioxide Capture and Separation Techniques for Power Generation Point Sources

The capture/separation step for carbon dioxide (CO2) from large-point sources is a critical one with respect to the technical feasibility and cost of the overall carbon sequestration scenario. For large-point sources, such as those found in power generation, the carbon dioxide capture techniques being investigated by the in-house research area of the National Energy Technology Laboratory (NETL) possess the potential for improved efficiency and cost savings as compared to more conventional technologies. The investigated techniques can have wide applications, but the research has focused on capture/separation of carbon dioxide from flue gas (postcombustion from fossil fuel-fired combustors) and from fuel gas (precombustion, such as integrated gasification combined cycle ? IGCC). Novel concepts are being developed in wet scrubbing with either chemical or physical absorption; chemical absorption or adsorption with solid sorbents; and separation by membranes. In one concept, a wet scrubbing technique is being investigated that uses an ammonia-based solvent to absorb carbon dioxide from the flue gas of a pulverized coal-fired power plant. In contrast, a physical solvent process to remove CO2 from fuel gas of an IGCC system at elevated temperature and pressure is being developed. Fabrication techniques and mechanistic studies for hybrid membranes separating CO2 from fuel gas produced by coal gasification are also being performed. Solid, regenerable sorbents that can be employed in either flue gas or fuel gas applications are being investigated. Progress with these sorbents that can be regenerated via a temperature and/or pressure swing has led to a demonstration within the Modular Carbon Dioxide Capture Facility constructed at NETL. An overview of the various novel techniques is presented along with a research progress status of each technology.