Performance of Dielectric Barrier Discharge Reactors on Elemental Mercury Oxidation in the Coal-Fired Flue Gas

The oxidation of elemental mercury (Hg⁰ ) by dielectric barrier discharge reactors was studied at room temperature, where concentric cylinder discharge reactor (CCDR) and surface discharge plasma reactor (SDPR) were employed. The parameters (e.g. Hg ⁰ oxidation efficiency, energy constant, energy yield, energy consumption, and O ₃ concentration) were discussed. From comparison of the two reactors, higher Hg⁰ oxidation efficiency and energy constant in the SDPR system were obtained by using lower specific energy density. At the same applied voltage, energy yield in the SDPR system was larger than that in the CCDR system, and energy consumption in the SDPR system was much less. Additionally, more O 3 was generated in the SDPR system. The experimental results showed that 98% of Hg ⁰ oxidation efficiency, 0.6 J·L ⁻¹ of energy constant, 13.7 µg·kJ ⁻¹ of energy yield, 15.1 eV·molecule ⁻¹ of energy consumption, and 12.7 µg·J ⁻¹ of O ₃ concentration were achieved in the SDPR system. The study reveals an alternative and economical technology for Hg 0 oxidation in the coal-fired flue gas.