Removal of sulfur dioxide pollutant from combustion gases through catalytic reaction and conversion that to sulfur

In this work, new method for removal of sulfur dioxide from combustion gases was studied. Al2O3, Cu-Al2O3, and Mo-Al2O3 were examined as the catalysts for reduction of sulfur dioxide to elemental sulfur with methane and their performances were compared in terms of SO2 conversion and selectivity. The effects of temperature, SO2/CH4 molar ratio, and reaction time on SO2 reduction were studied. The operating temperature range was 550–800 °C and it was observed that the reaction is strongly temperature dependent. Performance of the catalyst extremely enhanced when molybdenum and copper were added as promoters, and the Al2O3-Cu (10%) catalyst showed the best performance between of all the catalysts in terms of SO2 conversion and selectivity. For the Al2O3-Co(10%) as the best catalyst, the conversion of 99.5% and selectivity more than 99.5% were achieved at 750 °C. Effect of molar feed ratio of SO2/CH4= 3-1 was studied and stoichiometric feed ratio showed the best performance. Also, investigation of reaction time for catalysts showed a good long-term stability for SO2 reduction with methane in 5 hours.