Enhancement of Ca(OH)_2/Fly Ash Sorbent for the Dry-Desulfurization Process

摘要

Ca(OH)_2/fly ash sorbent has been studied as an effective method for SO_2 removal. The effect of iron and other species for enhancing the ability of Ca(OH)_2/fly ash sorbent was investigated in this study. At first, Fe(NO_3)_3 was added in the preparation of the sorbent, and TG analysis was carried out. The Ca utilization rate over a period of 90 min was about 10% greater than that for Ca(OH)_2/fly ash sorbent. However, it was found that iron is not effective for enhancing the ability of Ca(OH)_2/fly ash sorbent but that NO_3~- was the most effective factor to enhance it. The mechanism of enhancing the Ca utilization rate was also investigated, and it was found that Ca(NO_3)_2 was produced in the sorbent and reacted with SO_2, so that the reaction Ca(NO_3)_2 + SO_2 → CaSO_4 + 2NO + O_2 proceeded.