Study On Mn-based Catalytic Materials Of SCR At Low-temperature

Nitrogen oxide is one of the pollutant, and the important factor that acid rain, photochemical fog form. The nitrogen oxide mainly stems from coal-fired power plant, industry boiler and car exhaust, etc. Selective Catalytic Reduction (SCR) processes have been developed to convert the NOx to nitrogen and H₂O and thus limit the environment pollution.This text has expounded the fact of the domestic and international nitrogen oxide and the current situation of the technologys that the nitrogen oxide controled.Mechanism of SCR adsorption and SCR technological process and key influence factors of nitrogen oxide technology have been researched and analysed.Regard MnOx/TiO₂ and Fe₂O₃-MnOx/TiO₂ as the catalyst, use ammonia as reducing agent and get rid of NO in the exhaust gas of simulation, investigate under different experimental conditions separately in reflecting the result of getting rid of NO. Amount of temperature, loading, H₂O, O₂ and SO₂ react to SCR in the reactor of total mark of the fixed bed. AND SCR steady state reaction mechanism on manganese has been discussed. The experimental result indicates, the catalyst active component exists with the non- brilliant attitude, the catalyst active component is even in load.As to MnOx/TiO₂ catalyst, reaction temperature, airspeed and NH₃/NO were respectively under 180℃,15000h^-1 and 1:1 terms, the conversion ratio of nitrogen oxide can be up to 90%.As to the thing that taking off the nitre activity in NH₃, for reducing agent of Fe₂O₃-MnOx/TiO₂ catalyst, in the continuous reactor of the fixed bed, have studied different iron load amount, oxygen density, temperature, water and SO₂ impact on Fe₂O₃-MnOx/TiO₂ catalyst activity. The test result indicates, while regarding NH₃ as reducing agent, temperature is 120℃, the manganese load amount of iron is in 10%, airspeed is under 15000h^-1, the conversion ratio of nitrogen oxide is up to about 96%. NO turns into the conversion ratio of NO₂ rises and improves with temperature.O₂ is indispensable while the alternative catalysis reduce, the existence of water will compete with NH₃ and absorb leading to the fact the activity will be reduced, add, get, react.Lead to the fact H₂O +SO₂ ,NH₃ reduce NO activity reduce, most great NO conversion ratio drop six percentage point mix kind .The text has observed and analyzed the micro structure of two kinds of catalyst, than the surface area (BET) Analyze.The result indicates the active component is on the surface of carrier with the uniform distribution of the non- brilliant attitude, iron manganese influences each other in the dispersible state of the surface of carrier.