Study On The Intergration Process Of Desulfurization And Denitration Of Flue Gas Using High-efficiency Compound Ferrous Complexant

China is the largest consumer and producer of coal in the world.The atmospheric pollution and acid rain problems that caused by NO_x and SO₂ of flu gas,which has been a serious threat to the ecological environment and the health of citizens.Because of the high efficiency of desulfurization and denitrification in low temperature,the technology of complex ferrous iron will be the development direction of the future intergration process of desulfurization and denitration.In this paper,a double stirred tank reactor system and a small spray tower reaction system were established to study on the kinetics of denitrification and simultaneous desulfurization and denitrification experiment for Fe^ⅡEDTA and Fe^Ⅱ（CyS）₂.On the basis of the research results,this paper innovative put forward the high-efficiency compound ferrous complexant to remove NO and SO₂,and experimental studies on the optimization of the parameters of gas and liquid phase and the subsequent reduction regeneration were done in the small spray tower reaction system.The main conclusions are as follows:1)Under the standard conditions,that concentration of absorption solution was 0.05mol/L,initial pH was 8,reaction temperature was 323K,the simulated flue gas flow rate was 150L/h,the oxygen content was 5%,the concentration of NO and SO₂ were 500ppm and 1500ppm,the denitrification reaction rate constants of Fe^Ⅱ EDTA and Fe^Ⅱ（CyS）2 were 1.269×10⁹ L/（mol·s）,5.73×10⁸ L/（mol·s）;Fe^ⅡEDTA can maintain more than 50%of the denitrification rate in 70min and more than 90%of the desulfurization.Fe^Ⅱ（CyS）₂ can maintain more than 50%of the denitrification rate in only 15 min,but more than 90%of the desulfurization in 180min.2)Under the standard conditions,the compound complexant’s efficiencies of desulfurization and denitration were better than single complexant,it can maintain the denitration rate of 70%and the desulfurization rate of 100%in 90min;considered the actual conditions and experimental results,the compound complexant has the maximum absorption efficiency of denitration when the concentration of Fe^ⅡL was 0.05mol/L,the acid ratio was 12,the initial pH was 8,the concentration of Fe^Ⅱwas 0.075mol/L,the oxygen content was 5%,the flow rate of flue gas was 150L/h,and the concentration of SO₂ was 1500ppm.3)The regenerated solutions can be maintained more than 50%of the rate of denitrification in 40min under the standard conditions;and its denitrification effect increases with the increase of the concentration of Na₂SO₃,but when the concentration of Na₂SO₃ is higher than 18.9g/L,the effect of denitrification was not obvious increas;the regenerated solutions;efficiency of denitration becomes worse.with the increase in the number of regeneration.