ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Studies on the calcium poisoning and regeneration of commercial De-NO _x SCR catalyst

Jingying Li, Xiaolong Tang, Fengyu Gao, Honghong Yi, and Shunzheng Zhao

School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing, People’s Republic of China

E-mail: txiaolong@126.com

Abstract: The poisoning effect of calcium on a commercial De-NO_x SCR catalyst (V₂O₅–WO₃/TiO₂) and the regeneration process of deactivated catalysts via water or H₂SO₄ washing were investigated under simulated condition in laboratory. The physicochemical properties of the catalysts were characterized by SEM–EDX, XRD, BET, TPD and FT-IR measurements, and the deactivation mechanism was discussed. The poisoning of calcium was attributed to the coverage of active sites and the reduction of acid sites on the surface of catalyst. The change of V=O bonds on catalyst surface was an important reason, which plays a significant role in the catalytic cycle of SCR. Due to the suction deliquescence of CaO to Ca(OH)₂, the catalytic activity of deactivated catalyst can be finitely recovered by water washing. Besides, as the result of the re-exposure of active sites by washing CaO off and the promotional effect of surface sulfation, the process of regeneration via sulfuric acid washing has a favorable effect in the experiment.

Keywords: Reductions; Catalysts; Acidity; Surface

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-017-0186-8

Chemical Papers 71 (10) 1921–1928 (2017)