Theoretical And Experimental Study On Formation Mechanism Of Ammonium Bisulfate During Flue Gas Denitration Process

With the socio-economic development,the nitrogen oxides?NOx?in the main atmospheric pollutants of coal-fired boilers have become increasingly harmful to the environment and human health.As a main method of removing NOx from coal-fired flue gas,flue gas denitrification technology has the disadvantage that the escape NH₃produced by denitration can easily react with SO₃ in the flue gas to generate by-product ammonium hydrogen sulfate.Ammonium bisulfate is a highly viscous material that adsorbs fly ash in the flue gas and is hygroscopic at low temperatures,which can lead to fouling,clogging and corrosion of the air preheater when absorbed from the flue gas,Other equipment caused damage.Therefore,it is of great significance to carry out research on the formation mechanism of ammonium bisulfate for inhibiting the generation of ammonium bisulfate.Based on the theoretical analysis of the formation mechanism of ammonium bisulfate,from the perspective of chemical thermodynamics,the formation mechanism of ammonium bisulfate in thermal power plant is theoretically studied through the calculation of the conversion of thermodynamic parameters and chemical reaction.Based on the theoretical analysis,combined with self-built ammonium bisulfate decomposition and generation test bench,the decomposition temperature and decomposition rate of ammonium bisulfate and its influencing factors were studied.And the qualitative,semi-quantitative and quantitative aspects of its generation process simulation study.Studies have shown that the relationship between the ammonium bisulfate formation and decomposition characteristics and temperature,reactant concentration,and reactant molar ratio.As the temperature decreases,the molar ratio of reactants increases,and the conversion rate increases.When the concentration of reactants changes in the low concentration range,the effect on the conversion rate can be neglected.Ammonium bisulfate in the decomposition process,the decomposition rate and temperature is directly related to the starting decomposition temperature and the corresponding concentration of decomposition products,when the concentration is smaller,the higher the decomposition temperature.The above studies provide a powerful theoretical basis for the suppression of ammonium bisulfate formation by the boiler of coal-fired power plants.