Experimental Study On Removal Of SO₂, NO And Hg⁰ From Coal-fired Flue Gas By Pre-oxidation In Gas Phase

With the sustained and rapid growth of the energy and power demandings, power plants have become one of the biggest industrial pollution emissions in our country. The coal burning process in power plants generates plenty of SO2, NOx and heavy metal pollutants, which do serious harm to the environment and human health. Along with the constant improvement of the environmental requirements in China, the pollutant discharge standard of power plants is more and more strict. In "The power plant air pollutants emission standards" issued by the ministry of environmental protection in 2011, the sulfur dioxide and nitrogen oxide emissions standards have been closed to that of the developed country, the standard even added the emissions limits of mercury. Simultaneous desulfurization, denitrification and mercury removal have been widely concerned by the scholars at home and abroad. The study of simultaneous removal of the multi-pollutants in power plants has a positive meaning to improve the ambient air quality and construct the environmental friendly society.The issue reviewed the current desulfurization, denitrification and mercury removal technologies domestic and overseas, basing on a large number of literature at home and abroad for the urgent demand of our country to control the air pollutant, and designed a gaseous phase pre-oxidation process for simultaneous desulfurization, denitrification and mercury removal. A green efficient gaseous phase composite oxidant was prepared, under the simulating actual working condition the desulfurization, denitrification and mercury removal efficiency were studied with this oxidant. The best process conditions were decided, the effect of different flue gas components to desulfurization, denitrification and mercury removal efficiency were analyzed. The results prove that the best reaction condition was the residence time of 3s, reaction temperature of 130℃,pH of 4.5 Under the best reaction condition the efficiency of desulfurization, denitrification and mercury removal were 99%, 85%, 90%, respectly. The researching results provided basment data for the power plants to use this composited oxidant to achive multi-pollutant removal simultaneously in practical application.