Long-term operation of carbon dioxide capture system from a real coal-fired flue gas using dry regenerable potassium-based sorbents

Abstract

Abstract Korea Institute of Energy Research (KIER) and Korea Electric Power Research Institute (KEPRI) have been developing a CO 2 capture technology using dry sorbents. The CO 2 removal in dry sorbent CO 2 capture system consists of two reactors for carbonation and regeneration. We used dry sorbent manufactured by spray-drying method contains potassium carbonate, which was supplied by KEPRI in order to investigate the sorbent performance in continuous operation mode with solid circulation between a fast fluidized bed type carbonation reactor (13.5 m tall pipe of 0.075 m i.d.) and a bubbling fluidized bed type regeneration reactor (2 m tall bed of 0.25 m i.d.). We used the real flue gas from 2MW coal-fired circulating fluidized bed combustor to check possibility of deactivation of dry sorbent by contaminants such as SO x and NO x in the real flue gas for the 100 Nm 3 /hr of flue gas treatment facility. The residence time of the dry sorbents was about 3 seconds and 15 minutes in the carbonation reactor and the regeneration reactor, respectively. The CO 2 removal during 2 hrs in the whole experiments and the average CO 2 removal was above 70%. From the experiment, it was revealed that the removal of heat of sorption in the carbonation reactor was important to increase CO 2 removal. During the experiments continuous and smooth operation were accomplished with solid circulation between two reactors. These results indicate that CO 2 capture process using potassium carbonate solid sorbent is applicable for CO 2 capture in the coal-fired flue gas.