Effects of Reaction Conditions on Elemental Mercury Oxidation in Simulated Flue Gas by DC Nonthermal Plasma

Abstract

The effects of discharge polarity, discharge electrode configuration, O2/CO2 ratio, and water vapor on the elemental mercury (Hg0) oxidation in simulated flue gas were investigated in a wire-cylinder plasma reactor energized by DC power. The Hg0 oxidation efficiency increases with the increase of specific energy density (SED). Compared with the glow corona discharge energized by negative DC high voltage, the streamer corona discharge induced by positive DC high voltage exhibits a much higher Hg0 oxidation efficiency under identical SED. The discharge electrode configuration significantly influences the energy density in the plasma reactor, but hardly affects Hg0 oxidation for a fixed SED. The increase of O2/CO2 ratio in simulated flue gas obviously enhances Hg0 oxidation. However, with the addition of H2O, Hg0 oxidation is remarkably restrained due to the decrease of O3 formation.