Effect of Internal Structure on Flue Gas Desulfurization with Rapidly Hydrated Sorbent in a Circulating Fluidized Bed at Moderate Temperatures

Abstract

A moderate-temperature desulfurization process at 600−800 °C was studied in a pilot-scale circulating fluidized bed flue gas desulfurization (CFB-FGD) experimental facility with the addition of the internal structure. The rapidly hydrated sorbent and the desulfurization products were analyzed to clarify the influence mechanism of the internal structure on the moderate-temperature desulfurization process. The results show that the desulfurization efficiency with the internal structure at 600−800 °C was 74−93% for the calcium to sulfur (Ca/S) molar ratio of 2.0, which was higher than the desulfurization efficiency without the internal structure of 67−83%. As for the calcium-containing compositions, the desulfurization products included about 70% cyclone recirculation sample and about 30% bag filter sample. The cyclone recirculation sample was mainly composed of CaSO4 and CaO. The bag filter sample not only contained high contents of CaSO4 and CaO but also contained a considerable amount of CaCO3 and even so...