Effect of Sulfation during Oxy-Fuel Calcination Stage in Calcium Looping on CO_2 Capture Performance of CaO-Based Sorbents

摘要

Sulfation of calcium-based sorbent is bound to occur during carbonation or calcination of the sorbent in a calcium looping system if SO_2 is present in the system, and it will influence the CO_2 capture capacity of the sorbent While the effect of sulfation during the carbonation stage on the CO_2 capture capacity has been studied by some researchers, the effect of sulfation during the calcination stage has not been studied extensively. In this study, the effect of sulfation during the calcination stage under oxy-fuel combustion conditions on the CO_2 capture capacity of two calcium-based sorbents was investigated. The results showed that the calcination temperature and O_2 concentration of 5-20% had little effect on the sulfation of the sorbents, while SO_2 concentration and the presence of H_2O greatly influenced the cyclic performance of the sorbents. Furthermore, reducing calcination time seems to be an effective way to limit sulfation during calcination, because the sulfation rate is slow in the initial induction stage of the gas-solid reaction.