Study On Selective Catalytic Redution Of NO_x With NH₃ Using Wiremesh Honeycomb Catalyst

Nitrogen oxide (NOx) is one of the main pollutants in atmosphere. It does harm to human health and enviroment seriously. The amount of the NOx discharging is getting more and more. So it is a great of urgency to control the NOx pollution. Due to high efficiency, selection and economic value, selective catalytic reduction (SCR) is one technology for NOx control.The objective of this paper focuses on the catalyst which is the key question of SCR technology. Electrophoretic deposition (EPD) method was used to coat a porous aluminum layer on wiremeshes. Thermal sintering treatment and calcining process result in the formation of a thin Al2O3 layer in the outer surface of each deposited aluminum particle. Band flat sheets and the curved sheets was put together to form a honeycomb module with three-dimensional structure. The sol-gel method was adopted to load TiO2 and the dipping method to load V2O5 and WO3/ MoO3.Selective Catalytic Reduction (SCR) of NO with NH3 was used as model reaction. By testing the influence of the parameters on SCR in the course of catalyst preparation, it was found that when the loading amount of TiO2 was 0.4g, the module which weight 8g can be covered completely. The best loading amount of the active ingredient was V(1)-W(3)/TiO2 for binary catalyst. It was good for the SCR reaction to increase the mesh number of the catalyst in a certain extent. If Mo was added to the catalyst to form a ternary catalyst, the catalyst activity was improved evidently when the loading amount was V(1)-W(3)-Mo(6)/TiO2.The effect of reaction temperature, space velocity and NH3/NO ratio on SCR efficiency were evaluated. The result showed that the convertions of NO were increased with the temperature increasing. Through the preliminary research of the kinetics of the SCR reaction, it is found that the SCR reaction accorded with the first-order reaction. If the temperature was too high, with the temperature increasing, the efficiency would get worse; meanwhile, the increase of the space velocity would make the NO conversions reduced; the best NH3/NO ratio was 1:1.XRD, SEM, EDX energy spectrum, XPS analytical method were applied to...