CO2 Capture Using Phase-Changing Sorbents

A novel method for the postcombustion capture of CO2 from coal-fired power plants has been described utilizing an aminosilicone absorbent. 1,3-Bis(3-aminopropy1)-1,1,3,3-tetramethyldsiloxane (GAP-0) rapidly transforms from a low viscosity liquid to a friable solid upon exposure to CO2 in simulated flue gas. This material has excellent thermal stability, low vapor pressure, high CO2 loading capability, and a large dynamic CO2 capacity between rich and lean solvent loadings. Preliminary plant and process models assembled from experimental data show a decrease in parasitic energy loss from 30% to 18% when compared to the benchmark monoethanolamine (MEA) process and a concomitant lowering of the cost of electricity (COE) from 74% to 44% increase versus a plant without carbon capture.