Catalytic oxidation of elemental mercury in flue gas on MnOx/α-Al2O3.

Manganese oxide impregnated on α-alumina(MnOx/α-Al2O3) was employed as catalyst on the catalytic oxidation of Hg0 in the presence of hydrogen chloride.The optimized temperature of the catalytic oxidation reaction was around 300℃, where the Hg0 oxidation efficiency was up to 91% in the presence of 20mL/m3 HCl.Hg0 oxidation efficiency was kept over 90% when the space velocity was in range of 8000 h-1 to 32000 h-1.However, it decreased quickly when the space velocity was increased from 32000 h-1 to 96000 h-1.SO2 inhibited the mercury oxidation by occupying the activity sites on the catalyst, and the oxidation efficiency was reduced by about 20% in the presence of 500mL/m3 SO2.Meanwhile, the main reaction mechanism of catalytic oxidation was discussed.