Influence mechanism of corona discharge on flue gas conditioning in humid environment

In China, a decrease in collection efficiency of electrostatic precipitators (ESP) in some power plant has been observed after burned the ZHUNGEER coal. In order to find the way that the ESP effectively collect the sub-micron or extra-fine particles in flue gas, the mechanism that corona discharge oxidize the SO₂ in flue gas under different humidity conditions and SO₃ flue gas conditioning(FGC) have been studied. The results show that OH radical holds an important position for oxidation of SO₂, and it is mainly initiated by collisions between energetic electrons and water. In addition the water molecules adsorb and dissolve some SO₂, radicals, and provide a useful medium for the reaction. So the oxidation of SO₂ will largely improve in humid environment. The main oxidation products-SO₃ not only can improve the surface conductive of dust, but also increase adhesive force and agglomerate the fine particles to large size particles, improving collection efficiency of particles.