Study on volatilization characteristic of vanadium and tungsten of vanadium-based selective catalytic reduction

¹ China Automotive Technology and Research Center Co., Ltd, China
² Tianjin SwARC Automotive Research Laboratory Co., Ltd, China
³ Chinese Research Academy of Environmental Sciences, China

^* Corresponding author: nihong@vecc.org.cn

Abstract

Vanadium-based selective catalyst reduction (V-SCR) has made significant contributions to De-NOx of diesel vehicles. However, the two main catalyst components, V₂O₅ and WO₃, are volatile and toxic. Therefore, there are some restrictions for its application on heavy duty diesel vehicles (HDDV) in the CHINA VI stage. In view of this problem, the volatilization rates of two kinds of volatiles under different inlet temperature and test duration were measured on three V-SCR samples from different catalyst manufacturers. The effects of V-SCR inlet temperature and test duration on the volatilization characteristics of the two volatiles on different samples were systematically studied and compared. The emission concentrations of V₂O₅ and WO₃ at different temperatures were compared with the occupational exposure limits of chemical harmful factors in the workplace which is specified in the GBZ 2.1-2019. The results show that the initial temperature of volatilization of V-SCR is directly related to the technical level of the catalyst itself; whether the volatilization characteristics of V-SCR will change with the prolongation of test duration depends on its inlet temperature; V₂O₅ emission concentration of V-SCR at 550 C° can reach a quite high exposure level, and the exposure level of WO₃ volatiles at 650 C° may be equivalent to that of V₂O₅ volatiles at 550 C°.