Flue Gas Desulfurization by Dielectric Barrier Discharge

Abstract

There are many problems with flue gas desulfurization by traditional gas ionization discharge, including the large size of the plasma source, high energy consumption, and the need for a traditional desulfurization method. This paper introduces oxidization of SO2 to sulfuric acid (H2SO4) in a duct by reactive oxygen species (O2 +, O3) produced by strong ionization dielectric barrier discharge. The entire plasma reaction process is completed within the duct without the use of absorbents, catalysts, or large plasma source. The reactive oxygen species O2 + reacts with gaseous H2O in the flue gas to generate ·OH radicals, which can oxidize trace amounts of SO2 in large volumes of the flue gas to produce H2SO4. Sulfuric acid is also produced by O3 oxidation of SO2 to SO3, and SO3 reacting with gaseous H2O in the flue gas. Experimental results showed that with a gas temperature of 22 °C and reactive oxygen species injection rate of 0.84 mg/L, the SO2 removal rate was 81.4 %, and the SO4 2− concentration in the recovered liquid H2SO4 reached 53.8 g/L.