Effect of flue gas components on the NO removal and element mercury oxidation performance of Mn-modified low-temperature catalyst

Abstract

Abstract The development of a low-temperature water and sulfur-resistant catalyst with high efficiency of NO removal and element mercury Hg(0) oxidation performance is one of the main directions for the synergistic removal of multiple pollutants from flue gas. The transition metal Mn is used to modify the V-W/Ti catalyst to prepare a modified Mn-SCR catalyst. The effects of Mn loading and complex flue gas components (SO2, H2O and HCl) on the modified catalysts activity were investigated on a small fixed-bed experimental bench, respectively. As the Mn loading increases, the acid sites on the catalyst surface are significantly enhanced, the window of NO removal temperature is significantly widened, and the Hg(0) oxidation performance is nearly 100%. The optimal loading amount of Mn is 0.2(Mn/Ti, mol). When the Mn loading exceeds 0.2, the particles on the catalyst surface sinter, and the specific surface area decreases. However, little difference is observed in catalyst activity. When SO2 and H2O are present in the flue gas, dual-action catalyst activity can be significantly suppressed, but the effect of H2O on catalyst activity is greater than that of SO2. With the increase of the HCl concentration from 0 ppm to 50 ppm, the oxidation efficiency of Hg(0) and the removal efficiency of NO increased slightly.