Preparation Process Of Mn-ce Modified Vanadium-titanium Catalyst And Its Nh₃-scr Denitrification Performance

With the acceleration of urbanization and industrialization,the emission of nitrogen oxides is increasing,resulting in increasingly prominent environmental pollution problems.The main sources are incineration of fuels,industrial boilers,cement plants,thermal power plants,and some chemical plants.Exhaust gas emissions,automobile exhaust emissions,etc.,have a great impact on human health,such as cough,asthma,etc.,so controlling the emission of nitrogen oxides has become the focus of national attention.Automobile exhaust is an important source of nitrogen oxides,so it is particularly important to control automobile exhaust.Due to the advantages of high thermal efficiency of diesel engines,low fuel consumption rate,good reliability,strong power,etc.,dieselization of cars is now very common.The traditional V₂O₅/TiO₂-based SCR catalyst using ammonia as a reducing agent has good sulfur resistance and denitration efficiency.Gao has become a hot research technology today,but in practical applications there are problems such as complex operating conditions,poor low-temperature activity,high light-off temperature,and narrow active temperature window.The current research on denitration catalysts is mainly focused on the development of high-performance low-temperature catalysts.In some non-electric industries,where the flue gas temperature is generally low,to achieve ultra-low emissions,low-temperature catalyst SCR technology must be used.Therefore,research on new low-temperature catalysts has great practical value.Manganese-cerium-based catalysts have been widely studied due to their good activity in the low temperature range.Therefore,in this paper,the Mn and Ce co-doped V₂O₅/TiO₂ catalysts were prepared by the sol-gel method and the impregnation method,and different Mn/Ce mass ratios were studied And the effect of the calcination temperature of the carrier on the activity of the catalyst,and the change of the catalyst denitration performance with the reaction conditions was investigated,and the water and sulfur resistance of the catalyst was tested.At the same time,a VTi?Mn-Ce?shaped catalyst was prepared,the effect of water powder mass ratio,different additives and the amount of additives on the catalyst activity and radial strength were investigated,the optimal content of the loaded active component was determined,and the simulation was studied Influence of flue gas working conditions on catalyst denitration performance.The test results show that the co-doping of Mn and Ce does effectively improve the low-temperature activity of the catalyst.When the mass ratio of Mn/Ce is 0.4,the calcination temperature of the carrier is 500?,the reaction temperature is 240?,the mass fraction of O₂ is 5%,the empty When the speed is 60000h-1,the ammonia-to-nitrogen molar ratio is 1,and the NO inlet mass concentration is 600mg/m³,the activity of the VTi?Mn-Ce?x₄ catalyst reaches the maximum,about 98.4%.When 5%H₂O and 500mg/m³ SO₂ were introduced,the catalyst showed better water and sulfur resistance.Through the research on the preparation process of the shaped catalyst,the test shows that when the water-to-powder mass ratio is 0.5,the humidity of the shaped catalyst is appropriate,and the material can be clearly seen to be more compact and not easily dispersed when kneaded.When only phosphoric acid is selected as the auxiliary agent,the catalytic performance is the best.When the mass ratio of phosphoric acid to the material is 0.3,the radial strength reaches the maximum,which is 88N/cm.The effect of different working conditions on the activity of the shaped catalyst was studied.The test results showed that the catalyst activity continued to increase when the NO₂/NO_X molar ratio was in the range of 0.1⁰.5.When the NO₂/NO_X molar ratio was 0.5,the catalyst denitration performance was the best.When the imported NO mass concentration is 0.06%and the height-to-diameter ratio is 1.6,the catalytic activity is better.After the introduction of H₂O and SO₂,the catalytic activity remained above 90%,which was at a very high level,indicating that the catalyst had good water and sulfur resistance.