Dynamic Model And Experimental Research Of SCR Flue Gas Denitration Reaction Tower

Nox is one of the major air pollutants, which causes acid rain and photochemical smog, affecting the ecological environment and endangering human's health. So the control of NOx emission has been widely concerned.The technology of Selective Catalytic Reduction flue gas denitration has been the main choice to control Nox emission for coal-fired boilers, because of its high denitration rate (up to 90%) and maturity. However, this technology started relatively late in china and a number of problems were encountered in the actual system design and operation.The catalyst of V2O5-WO3/TiO2 was selected to investigate the denitration reaction external mass transfer process,internal mass transfer process and interface chemical reactions process, and the macro-kinetic model were established.Three catalyst with different active substances were calculated by the model, and the effect of temperature, residence time, ammonia-nitrogen ratio, oxygen concentration and NO concentration were studied.The experimental device used to simulate SCR was constructed,and the gas flow is about 150m3/h. The the macro-response performance of catalyst was studied by orthogonal test, from which the basic data for the quantitative relations of denitration were obtained. The correctness of the mathematical model was also verified, and the result shows: The importance of the factors on the denitrification efficiency index are followed as:B, D, A, E and C respectively, temperature is the most important factor on the denitrification efficiency. The optimum scheme is A4B2C2D4E1. In the condition that without taking into account the influence of oxygen concentration, the importance of the factors on the denitrification efficiency index are followed as:A,D,B and C,respectively.The optimum scheme is A4B2C2D4, which matches well with the scheme obtained in test. Therefore, the model calculations are in good agreement with experimental results.The mathematical model can reflect the law for the main operating parameters of the reactor. Denitration efficiency rised with the increase of specific surface area, residence time, ammonia-nitrogen ratio and the reaction temperature.However, the trend of growth gradually slowed.The flow rate of gas has no effect on the denitration efficiency.This result matches well with the experiment results, suggesting the model is appropriate.Therefor, this model can be used to improve the denitration device and operation analysis.