Demonstration of pilot scale carbon dioxide capture system using dry regenerable sorbents to the real coal-fired power plant in Korea

Abstract

Abstract Korea Institute of Energy Research (KIER) and Korea Electric Power Research Institute (KEPRI) have developed the carbon dioxide (CO 2 ) capture system using dry regenerable sorbents since 2002. The principle of the CO 2 capture with regenerable solid sorbents is the reversible reaction between potassium carbonate and potassium bicarbonate in a thermal-swing process. Based on this reaction, we developed a bench scale unit (BSU) which treated 100 Nm 3 /h of flue gas in late 2006. The BSU consisted of a transport fluidized-bed carbonator, cyclones, a loop-seal, and a bubbling fluidized-bed regenerator. We have tested the BSU facility using a slip stream of the real flue gas from a coal-fired circulating fluidized bed combustor located at KIER in order to check the performance of CO 2 removal, the stability of operation. The results showed that more than 80% of CO 2 removal had been maintained during more than 50 hour continuous operation and its maximum reached at the 85% level. Those results indicated that the CO 2 capture system using solid sorbents developed here could be applied to coal-fired power plant. In the meanwhile, we set the small scale unit which consists of two bubbling beds for carbonation and regeneration in order to investigate the effect of several operating variables on the CO 2 removal. The performance of the small scale unit was investigated through the continuous operation with solid circulation under the same experimental conditions as the BSU facility. The CO 2 removal of the small scale unit was reached at the 83% level with the inlet CO 2 concentration of 10 vol.%. The CO 2 removal increased as the water vapor content in the inlet flue gas stream, regeneration temperature, and solid circulation rate increased while it decreased as the gas velocity of the carbonator and carbonation temperature increased. It was found that the performance of the CO 2 removal was very sensitive to the water vapor content in the inlet gas stream and the gas velocity of the carbonator (gas-solid contact time in the carbonator). The construction of 0.5 MW scale pilot plant based on the results of BSU at KIER has been finished in late 2009 at the Hadong Coal-Fired Power Plant, Korea Southern Power Company. The overall performance of pilot plant showed very promising and its CO 2 capture performance reached at the 85% level. A 10 MW scale CO 2 capture plant next development step after 0.5 MWe at the Hadong Coal-Fired Power Plant will be started to construct at the same site in late 2011.