Simultaneous CO2/SO2 Capture Characteristics of Three Limestones in a Fluidized-Bed Reactor

Simultaneous CO 2 /SO 2 capture characteristics of three limestones were investigated in a pilot scale fluidized-bed reactor. For each of these sorbents, the measured CO 2 capture capacity decreased as the number of cycles increased and as the SO 2 concentration increased. On the other hand, the SO 2 capture increased with the number of cycles and the SO 2 concentration. The total calcium utilization decreased as the number of cycles increased, but the effect of SO 2 concentration on the total calcium utilization depended on the sulfation pattern of limestone. For one limestone (with unreacted-core-type sulfation), the total calcium utilization decreased with increasing SO 2 concentration. However, for the other two limestones (with uniform-type sulfation), the total calcium utilization was almost independent of SO 2 concentration for the range investigated. The results show that SO 2 reduces the CO 2 capture capacity of limestone and indicate that the sulfation patterns affect the CO 2 capture capacity.