Effects of particulates, heavy metals and acid gas on the removals of NO and PAHs by V_2O_5-WO_3 catalysts in waste incineration system

摘要

This study investigated the activities of prepared and commercial V_2O_5-WO_3 catalysts for simultaneous removals of NO and polycyclic aromatic hydrocarbons (PAHs) and the influences of particulates, heavy metals, SO_2, and HO on the performances of catalysts. The experiments were carried out in a laboratory-scale waste incineration system equipped with a catalyst reactor. The DREs of PAHs by prepared and commercial V_2O_5-WO_3 catalysts were 64% and 72%, respectively. Increasing the particulate concentrations in flue gas suppressed the DRE of PAHs, but increasing the carbon content on surface of catalysts promotes the NO conversions. The DRE of PAHs by the catalysts was significantly decreased by the increased concentrations of heavy metal Cd, but was promoted by high concentration of Pb. The influence level of SO_2 was higher than HCl on the performances of V_2O_5-WO_3 catalysts for PAHs removal, but was lower than HCl for NO removal. Prepared and commercial V_2O_5-WO_3 catalysts have similar trends on the effects of particulates, heavy metals, SO_2, and HCl. The results of ESCA analysis reveal that the presences of these pollutants on the surface of catalysts did not change the chemical state of V and W.