Effect of Loading Fe₂O₃ on Microwave Desulfurization and Denitrification of Activated Carbon

Objective To explore the performance and mechanism of activated carbon loaded with Fe₂O₃ in the synergistic removal of SO₂ and NOx from sintering flue gas under microwave field, in order to lower the reaction temperature, reduce carbon loss, and provide a theoretical basis for efficient and low-cost flue gas desulfurization and denitrification. Method Taking the loaded Fe₂O₃ activated carbon as the breakthrough point, Fe₂O₃-loaded activated carbon (Fe₂O₃/AC) was prepared by the impregnation method. The effect of Fe₂O₃ loading on microwave desulfurization and denitrification of activated carbon was investigated by Fe₂O₃/AC characterization detection and desulfurization and denitrification experiments. Result&Conclusion The loading effect of Fe₂O₃/AC was better at the experimental conditions of iron nitrate solution concentration of 10%, temperature of 400 ℃ and holding time of 1 h. The desulfurization rate and denitrification rate of microwave alone at 300 ℃ reached 90.2% and 81.8%, respectively. The effect was better than that of ordinary activated carbon. During the reaction process, some Fe₂O₃ reacted with SO₂ and NO to form corresponding sulfate and nitrate at aerobic conditions. With the increase of temperature, the microwave synergistic desulfurization rate and denitrification rate showed a significant upward trend. The presence of NO is beneficial to the removal of SO₂. The maximum removal rate of SO₂ reaches 95% at 300 ℃, which is higher than that of desulfurization alone. When the reaction temperature rises to 420 ℃, the synergistic desulfurization rate is close to 100%. The presence of SO₂ will inhibit the removal of NO, and the maximum removal rate of NO is 66.5% at 300 ℃.