Effect of Flue Gas Purification Facilities of Coal-Fired Power Plants on Mercury Emission

Abstract

Mercury emission of 38 coal-fired power plants in China from published literatures has been summarized and analyzed. The results show that clean flue gas of coal-fired power plant is mainly composed of gaseous mercury and mercury emission concentration in different units has very large difference. The selective catalytic reduction catalyst promotes oxidation of Hg0 to Hg2+ and the oxidation of Hg0 is greatly affected by chlorine content in coal. The dust removal facilities affect mercury emission by removal of HgP, and the mercury removal efficiency of fabric filter is higher than that of electrostatic precipitator. Wet flue gas desulfurization affects mercury by removal of gaseous mercury, depending on Hg2+. Mercury removal efficiency from the coal-fired power plants equipped with selective catalytic reduction denitration, dust removal facilities and wet flue gas desulfurization is higher.