under these conditions is challenging because: (1) the low pressure and dilute concentration dictate a high total volume of gas to be treated; (2) trace impurities in the flue gas tend to reduce the effectiveness of the CO2
separation processes; and (3) compressing captured CO2
from atmospheric pressure to pipeline pressure (1,200 - 2,200 pounds per square inch) represents a large parasitic energy load.
DOE/NETL's post-combustion CO2 control technology R&D program includes projects directed at the use of solvents, solid sorbents, and membranes. Amine-based solvent systems are in commercial use for scrubbing CO2 from industrial flue gases and process gases. However, solvents have not been used to remove large volumes of CO2 as would be encountered in a PC-fired utility boiler flue gas. Solid sorbents can be used to capture CO2 from flue gas through chemical adsorption, physical adsorption, or a combination of the two effects. Possible configurations for contacting the flue gas with solid sorbents include fixed, moving, and fluidized beds. Membrane-based capture uses permeable or semi-permeable materials that allow for the selective transport/separation of CO2 from flue gas.
DOE/NETL is currently funding multiple post-combustion CO2 emission control projects employing each of these three approaches. These R&D efforts are being performed by external research organizations and academic institutions, as shown below, and by NETL's Office of Research and Development (ORD), specifically the Separations and Fuels Processing Division and the Office of Computational Dynamics.
The In-House Post-Combustion CO2 Control webpage provides detailed information regarding NETL’s internal R&D. Collapse Text