Study On Denitration Performance Of SCR In Low Temperature For Modificated Fe₂O₃/AC Catalyst

With the development of economy of our country, the electric power industry has become much more prosperous and the quantity of motor vehicles is increasing rapidly. The same change has happened in raw materials, chemical fertilizers, glass and other manufacturers. The amount of NOx in the exhaust gas released by these factories becomes larger every year. This leads to a series of environmental problems.NH3 selective catalytic reduction technique was widely used in pollutant controlling because of high efficiency, convenient transformation and so on. The performance of catalyst is the key of the whole technology. Therefore, it is very important to develop a kind of catalyst with high performance and environment harmless.The low temperature SCR performance of Fe₂O₃/AC catalyst?short as Fe/AC? with different load of Fe were studied in this paper and the performance of catalysts are analyzed. Further, the low temperature SCR performance of modified Fe/AC catalysis with Mn, Co, Cu was investigated under different conditions. The properties of catalysts are characterized by XRD, BET, XPS, TG, H2-TPR and NH3-TPD. The results are as follows.?1? 10Fe/AC has the highest activity and a larger specific surface area for Fe/AC catalysts with different Fe contents. XRD results show that the main forms of Fe are ?-Fe₂O₃ and ?-Fe₂O₃ in different catalysts.?2? The addition of Mn, Co and Cu can increase the activity of Fe/AC catalysts. The denitration efficiency is better when the ratios of Fe/Mn molar ratios are 10:1,10:3 and 10:5 in Fe/AC catalysts. And the conversion rate of NO was close to100%. The best ratio of Fe/Co is 10:7, and the NO conversion rate is 91%, but it only occurs when the temperature is higher than 200 ?. The highest NO conversion rate is 81.2% when the ratio of Fe/Cu is 10:1.?3? XRD results show that Mn, Co and Cu in the catalyst hardly exist in the form of crystal. BET results show that the specific surface area of the catalyst decreases gradually with the increasing of content of the active component. XPS analyses find that the main existence valence state of Fe in 10Fe/AC catalyst is Fe3+, and the state of Mn in the catalyst with highest activity is Mn3+ and Mn4+. TG analyses show that the catalyst has good oxidation resistance when the content of active component is high. Both H2-TPR and NH3-TPD analyses show that the catalyst has better performance when the amount of Mn is reduced.?4? The addition of Ce can improve the low temperature activity of Fe-Cu/AC catalyst. The flue gas simulation experiment results and tube furnace show that the catalyst has better performance when the calcination temperature is 400?.