Experimental Study On Desulfurization And Denitrification Of Coal-fired Flue Gas Catalytic Oxidation

With the development of economy,the emissions of SO2 and NOX became more and more higher;so the air pollution is becoming more serious than before.In recent years,China has published strict emissions standard of SO2 and NO,and strengthen governance measures.The SO2 and NOX pollutants in air mainly come from the emission of coal-fired flue gas;under the circumstances,we should control the emission of coal-fired flue gas.As foreign has controlled the emissions of SO2 and NOX earlier,the study of desulfurization and denitrification is very broad,governance technology is also more mature,especially the desulfurization technology which is high efficiency,economical and practical;relatively,the denitrification technology is not mature enough.At present,the SCR method is more applications in industrialization,which is high denitrification efficiency,but its produces caused secondary pollution,as well as high investment costs;therefore,It is necessary to study new technology which is simultaneous desulfurization and denitrification.In this article,we study two methods that desulfurization and denitrification: gas/solid phase catalysis and liquid phase oxidation absorption.The gas/solid phase catalysis is different from traditional method,it's advantage is that SO2 and NOX can be removed at the same time,it doesn't use reduction gas and precious metals,and has no secondary pollution,as well as low cost.The method adopts spherical Na-ZSM-5 molecular sieve with silicon to aluminum ratio of 25 as the catalyst carrier,which load Cu as the main denitrification active component,V as the main desulfurization active component,it used the method of secondary dipping to make Co?1%?,Cu?1%?-ZSM-5 catalyst which has the best catalytic activity,then we studied the compatible evaluation conditions.In this condition which temperature is 350? and gas flow rate is 60mL/min,the desulfurization rate is 100%,the average denitration rate is 61%,the concentration of NO in the treated tail gas is 524mg/m3,this emission is far less than 200mg/m3 which is emission standard.Liquid oxidation method has more advantages such as simple operation,low investment and operating cost,high rate of desulfurization and denitrification.KMnO₄ oxidant which has selected,has advantages of high economic efficiency,strong oxidative NO and environmental protection.In the Lab scale,the flow of flue gas is 400mL/min,the concentration of KMnO₄ solution ies 0.04mol/L and the volume is 400 mL,the gas inlet of the oxidation absorption reactor was equipped with gas distributor,their are the optimal evaluation conditions of KMnO₄ oxidant.Under optimum condition,the desulfurization rate is 100%,the desulfurization effect is stable,the denitrification rate is up to 93%,the denitrification effect is also stable;the running time that satisfied the emission standard is about 10h30 min.After the same amount of KMnO₄ was added,the denitrification effect is increase obviously than before,even has the same effect as initial.