Preparation And Study Of SCR Low Temperature Denitration Catalyst

As one of the main pollutions of China’s atmospheric environment,nitrogen oxides not only cause environmental problems such as acid rain and photochemical pollution,but also are the main components of PM2.5.With the release of a series of documents and measures,the removal of nitrogen oxides is an urgent task.At present,ammonia selective catalytic reduction(NH3-SCR)is widely used in the removal of fixed source NOX in the world,but the application temperature of the main core SCR catalyst of this technology is 300-420 ℃,which is generally suitable for power plant industry.Some non-power plant industries(metallurgical furnaces,cement,steel sintering furnaces)generally have a flue gas temperature of 120-300℃.Conventional commercial denitration catalysts cannot be directly applied.Therefore,it is also necessary to develop some high-efficiency and economical low-temperature denitration catalysts.This paper first briefly introduces the hazards of nitrogen oxides,sources,current status of nitrogen oxides emissions in China,emission reduction technologies of nitrogen oxides,and research progress in process and denitration catalysts.In the end,the paper used titanium dioxide as carrier carrier and metal oxide as active component to prepare SCR low-temperature denitration catalyst.A series of low-temperature denitration catalysts were developed by optimizing the carrier and using different methods to load the active components.The prepared SCR low temperature catalysts were characterized by scanning electron microscopy(SEM),specific surface area(BET),thermogravimetric analysis(TG)and X-ray diffraction(XRD).The results are as follows:N-doped TiO2 support was prepared,and the active components such as Fe,Cu,Ce,Mn,La were loaded by the three methods of step-by-step impregnation,precipitation and co-impregnation,and found through experiments:doped N pairs The denitrification activity of the catalyst was greatly improved.The evaluation of the performance of the catalyst showed that the catalyst had the highest denitration efficiency at 220℃,a space velocity of 19,000 h-1 and an ammonia to nitrogen ratio of 1,Can reach 93%.optimization of catalyst reaction process conditions;this paper takes a new method to treat the precursor of the active component,the active component is impregnated,by changing the content of the active component,calcination temperature,reaction space velocity and reaction temperature Filter by conditions.Finally,a better preparation method of the catalyst is obtained.When the ammonia-to-nitro gen ratio is 1,the catalyst has a denitration rate of 1 00%at a reaction temperature of 220-260℃.