Effective dry desulfurization by a powder-particle fluidized bed.

Abstract

In a process of flue gas desulfurization by use of dry limestone, the smaller the particle size of the limestone, the higher is the SO2 conversion expected. In a powder-particle fluidized bed (PPFB) fine particles less than 40 μm in diameter fed into the bed are fluidized with coarse particles. But only the fine particles are entrained from the bed, and their residence time in the bed is remarkably long. In this study, PPFB, was applied to a desulfurization process. SO2 conversion from a model gas was investigated with a laboratory-scale PPFB, and the effect of the operating conditions on SO2 conversion was examined. SO2 conversion was affected by reaction temperature, Ca/S ratio, particle size of limestone and static bed height. When the temperature was about 1073 K, SO2 conversion reached its maximum. 100% of SO2 conversion was obtained at Ca/S = 3 in the temperature range between 1073 K and 1223 K.