Effect of Vanadium Oxide Loading for the Simultaneous NO Reduction and Hg0 Oxidation over a V2O5-WO3/TiO2 Catalyst

Simultaneous NO reduction (NOred) and Hg-0 oxidation (Hg-oxi(0)) in the exhaust gas of a coal-fired power plant were studied by using V2O5-WO3/TiO2. The increase in vanadia contents and temperature concurrently increased NOred and Hg-oxi(0). However, the increase in NH3 increased NOred but decreased Hg-oxi(0) and the increase in HCl increased Hg-oxi(0). At 350 degrees C, when the vanadia content and HCl and NH3 concentrations were less than 2.5%, 40 ppm, and 400 ppm, respectively, rate constants of Hg-oxi(0) and NOred were between 2031 to 23,655 and 131 to 737 m(3)<middle dot>mol(-1)<middle dot>s(-1), respectively. NOred and Hg-oxi(0) rate constants were increased by the increase in vanadia contents, although the NOred rate constants were similar at 2.0 and 2.5% vanadia contents due to the surface saturation. Using 2.0% vanadia contents with a minimum HCl concentration of 10 ppm, more than 85% NO and Hg-0 can be removed under simulated flue gas conditions.