Liquid-Impregnated Clay Solid Sorbents for CO2 Removal from Postcombustion Gas Streams

Abstract

A novel liquid-impregnated clay sorbent [R. V. Siriwardane, U.S. Patent No. 6,908,497 B1 (2003)] was developed for carbon dioxide (CO2) removal in the temperature range of ambient to 60°C for both fixed-bed and fluidized-bed reactor applications. The sorbent is regenerable at 80–100°C. A 20-cycle test conducted in an atmospheric reactor with simulated flue gas with moisture demonstrated that the sorbent retains its CO2 sorption capacity with CO2 removal efficiency of about 99% during the cyclic tests. The sorbents suitable for fluidized-bed reactor operations showed required delta CO2 capacity requirements for sorption of CO2 at 40°C and regeneration at 100°C. The parameters such as rate of sorption, heat of sorption, minimum fluidization velocities, and attrition resistance data that are necessary for the design of a reactor suitable for capture and regeneration were also determined for the sorbent. A 20-cycle test conducted in the presence of flue-gas pollutant sulfur dioxide—SO2 (20 parts per million)—indicated that the sorbent performance was not affected by the presence of SO2.