Multiple-Cycles Behavior of K2CO3/Al2O3 for CO2 Capture in a Fluidized-Bed Reactor

The sorbent of K2CO3/Al2O3 is a good choice for CO2 capture from flue gas of fossil-fuel-fired power plants. The CO2-capture capacity and regeneration property for K2CO3/Al2O3 were investigated in a bubbling fluidized-bed reactor during multiple cycles. Results show that the carbonation conversion for K2CO3/Al2O3 is greater than 90% during 10 cycles. The microstructure character of K2CO3/Al2O3 is stable. The changes of surface area and pore volume are 8.3 m(2)/g and 0.036 cm(3/)g, respectively, after 10 cycles, and there is little change in the pore size distribution. Careful temperature control is important because of the narrow temperature window available for CO2 capture and the highly exothermic nature of the carbonation process. After 10 cycles, the elutriated sorbent is only 2.8 wt% and the reducing rate of average particle size is 0.005 mm/h. The sorbent of K2CO3/Al2O3 shows excellent attrition reassistance performance.