Study On Simultaneous Desulfurization And Denitrification Technology Of NaClO/KMnO₄ Composite Oxidation Absorption Liquid

At present,the energy structure in China is still dominated by coal,and most of the coal is consumed by direct combustion.The flue gas produced by coal combustion contains a large amount of SO₂ and NO.If directly discharged into the air,it will form acid rain,haze,photochemical smog and so on,which will cause harm to the atmospheric environment and human beings.Therefore,it is necessary to carry out desulfurization and denitrification treatment of SO₂ and NO in the gases.Currently,the most widely used technology of desulfurization and denitrification in the industry is combined usage method with limestone-gypsum wet desulfurization and the selective catalytic reduction?SCR?denitrification.This method requires two sets of devices in industrial application,which increases the investment of equipment and area,and the complex pipeline in the device is not conducive to maintenance and operation.Therefore,the research on simultaneous desulfurization and denitrification technology has important significance and application prospects.NaClO is very oxidative and inexpensive,so it is very suitable for simultaneous desulfurization and denitrification of flue gases,but only a few scholars have conducted research in this area.In this paper,the simultaneous desulfurization and denitrification of flue gas was studied in a self-made bubbling reactor by configuring NaClO/H₂O₂ and NaClO/KMnO₄ composite oxidation absorption liquid,which add a certain amount of H₂O₂,KMnO₄ into NaClO,respectively.However,the effect of simultaneous desulfurization and denitrification of NaClO/H₂O₂ composite oxidizing absorption liquid is not ideal.Therefore,the effects of NaClO concentration,KMnO₄ concentration,gas velocity,solution pH value and solution temperature on simultaneous desulfurization and denitrification efficiency were studied in this paper.According to the experimental results,the optimum reaction conditions were determined as follows:NaClO concentration is 40mmol/L;KMnO₄ concentration is 7.5 mmol/L;gas velocity is 120 L/h;solution pH value is 12;solution temperature is 25?.Under the optimum reaction conditions,the conversion rates of SO₂ and NO in simulated flue gas were 100%and 95%,respectively.Moreover,the composite solution can maintain a very high conversion rate of NO in the range of pH 6-12,which has a very good application prospect in the industry.The reaction mechanism of oxidation and absorption process was deduced by determining the ion species and concentration in the composite absorption solution before and after the reaction,and then the reaction kinetics equations of SO₂ and NO were fitted,respectively.The results show that the reaction order of SO₂ and NO is 1 and 1.3,respectively,and the reaction activation energies are 72.5 kJ/mol and 35.6 kJ/mol,respectively.The obtained kinetic data provide theoretical and enlargement basis for the subsequent pilot-scale amplification experiments.