Flue Gas Desulfurization through Catalytic Oxidation of Coal Slurry

Based on the principle of aqueous catalyzed oxidation,coal slurries were used as SO2 scrubbing medium.The catalyst Fe2+/Fe3+ was produced in situ through the reaction of coal pyrite with SO2 and O2.Experimental concentration ranges of SO2 and O2 in the gas were 760Х10-6～ 3200Х10-6 and 3%～20% respectively.SO2 removal efficiency was more than 90% when the reaction temperature was above 40℃.SO2 removal efficiency decreased as SO2 concentration increased,which was similar as the wet lime/limestone flue gas desulfurization process.No significant effects were observed of pH value and O2 concentration on SO2 removal within the experimental range,and O2 concentration in actual flue gas was enough for the catalyzed oxidation.Total iron ion concentration in the slurry increased as the desulfurization reaction proceeded,which showed that the coal pyrite was being leached.This method can not only achieve high flue gas desulfurization efficiency but also reduce pyretic sulphur from coal.