Investigation of Gaseous Elemental Mercury Oxidation by Non-thermal Plasma Injection Method

Abstract

The non-thermal plasma injection method was used to oxidize elemental mercury (Hg0) in this study. A mixture of water vapor and oxygen was selected as the discharge gases. Active species generated by a dielectric barrier discharge plasma reactor were introduced into the flue gas duct, where they reacted with Hg0. Different parameters including active particles, supply voltage, flow rate of injection gas, system temperature, and typical flue gas components were considered. Experimental results indicated that it produced a high yield of oxidative species than using a single discharge gas, and the reason was believed to be the dissociation and excitation of water molecules and oxygen molecules by electron impact. It was assumed that active radicals include O, O3, water cluster ions (O2+·H2O), and ·OH. Increasing the plasma injection volume led to higher content of reactive species in the system, which promoted Hg0 oxidation. Approximately 98.3% of Hg0 was oxidized at 4 kV of voltage with 20 mL/min of plasma ...