Study on Denitration Performance of CeO2 Modified CuO/γ-Al2O3 Catalyst Under Deferent Flue Gas Components

Abstract

The effects of different flue gas components such as n(NH3)/n(NO) ratio, SO2 and H2O on the NO removing efficiency of Cu8Ce3 catalyst were studied in a fixed bed reactor. The experimental results show that the diffusion pressure and diffusion rate of NH3 in the catalyst microporous are the main factors affecting the NO removing efficiency, when n(NH3)/n(NO) ratio<1.05. The n(NH3)/n(NO) ratio no longer plays a decisive role in the denitration efficiency, when n(NH3)/n(NO) ratio >1.05. The effect of water vapor and SO2 on the denitration efficiency is different at 350°C and 400°C. The water vapor and NH3 have a competitive adsorption relationship on the catalyst surface, which reduces the adsorption of NH3 on the catalyst surface. This is the reason why the efficiency is suppressed at 350°C; the addition of water vapor can improve the surface acidity of the catalyst at 400°C, which is why the denitration efficiency is improved at this temperature. At 400°C, the adsorption rate of SO2 on the surface of Cu8Ce3 catalyst is higher than that at 350°C. As the temperature of flue gas increases, the adsorption amount of NH3 on the catalyst surface is reduced. This is why the denitration efficiency is depressed under the SO2 intervention. The adsorption and oxidation efficiency of NH3 in the sulfided catalyst at 400°C is improved, which is the main reason for the improvement of denitration efficiency at this temperature.