Basic Research On Catalytic Oxidation Treatment Of Nitrogen Oxides

NO_x can cause very serious pollution to the atmospheric environment and is one of the most important causes of frequent haze weather.The wet denitrification technology combined with urea and hydrogen peroxide is a catalytic oxidation method to treat NO_x,and it is an effective denitrification technology.In view of the reaction principle of urea denitrification and the absorption characteristics of urea solution for NO_x,this paper holds that using H₂O₂ as additive and urea absorption solution can achieve high efficiency removal of NO_x,and the product after reaction is non-toxic and harmless,and does not cause any harm to the environment.Therefore,this paper applys the method of quantum chemistry calculation and experiment to study,reveals the reaction mechanism of urea combined with hydrogen peroxide to remove NO,and finds an efficient and stable working condition for removing NO,which provides theoretical basis and experimental basis for subsequent technology development.The research content is mainly divided into two aspects:?1?Applying the method of Ub3 lyp from the beginning of quantum chemistry,the reaction path and reaction mechanism of urea combined with hydrogen peroxide liquid phase denitrification were calculated and studied.Calculations show that hydrogen peroxide is difficult to react directly with urea,because H₂O₂ will first and no redox reaction,the formation of a large number of HNO2,and HNO2 encounter urea solution,will be constantly consumed,the reaction to generate N2,CO2 and H2 O,and finally achieve denitrification.This reaction path is most likely to be carried out because it requires the least activation energy.According to this reaction path,the activation energy of urea denitrification reaction after calculation is about 77.51 k J/mol,and the reaction mechanism of urea combined with hydrogen peroxide liquid phase denitrification reaction is revealed,which provides a theoretical basis for the treatment of NO_x by catalytic oxidation method.?2?Using the experimental platform,the removal efficiency of urea absorbent solution to NO_x was studied under different conditions and when different additives were added.The experimental research mainly uses the bubble reactor and the constant temperature water bath,takes the urea solution absorbent,respectively to study the reaction temperature,the hydrogen peroxide content,the pulverized coal content,the activated carbon content and so on different conditions and the additive removal efficiency,and makes the further comprehensive experiment Research,compares the analysis,determines the urea denitrification experiment to get a better operational condition.In the temperature of 60?,the use of 10% urea absorption solution,0.3% pulverized coal,0.3% hydrogen peroxide,0.1% organic additives as the additive of urea absorption solution,can achieve high efficiency to remove NO_x,removal efficiency of about 90%,for catalytic oxidation treatment of NO_x provides a certain experimental reference.