Effect of the sulfur compounds structure on the SO2 conversion and capture in a bubbling fluidized-bed combustor

SO2 is the main pollutant produced by fluidized bed boiler. Most studies only consider the effect of operating parameters on SO2, while the influence of sulfur structure in coal is ignored. Combustion experiments using pure char loaded with various sulfur structures in a bench-scale bubbling fluidized bed combustor was carried out in this paper to determine the influence of different sulfur structures on SO2 conversion. Effects of excess air, bed temperature and desulfurization efficiency were also investigated. The experimental results show that the order of SO2 conversion is ferrous sulfate > 1-Dodecanethiol > pyrite > diphenyl sulfide > diphenyl sulfoxide > dibenzothiophene. Most sulfur models showed an increase in SO2 conversion with increasing temperature. When the excess air increases, the oxygen content in the furnace is increased, which is beneficial to the conversion of sulfur model to SO2. The desulfurization efficiency of ferrous sulfate and pyrite is higher than that of organic sulfur.