Experimental investigation on the decomposition of NH4HSO4 over V2O5-WO3/TiO2 catalyst by NH4NO3 at low temperature. (1st February 2023)

• Record Type: Journal Article
• Authors: Zheng, Ziwen; Du, Xuesen; Wang, Xing; Liu, Yanggu; Chen, Kunlu; Lu, Peng; Rac, Vladislav; Rakic, Vesna
• Is Part Of: Fuel. Volume 333(2023)Part 2
• Publication Date: 2023-02-01
• Subjects: NH4NO3 -- NH4HSO4 deposition -- Catalyst regeneration -- VWTi catalyst; Fuel -- Periodicals; Coal -- Periodicals; Coal; Fuel; Periodicals; 662.6
• DOI: 10.1016/j.fuel.2022.126443
• Languages: English
• ISSNs: 0016-2361

Abstract

Graphical abstract: Highlights: Adding NH4 NO3 broadened the operating temperature range of VWTi catalyst. The SCR activity of VWTi catalyst was improved at low temperature using NH4 NO3. The SO2 tolerance of catalyst was increased by using NH4 NO3. The addition of NH4 NO3 accelerated the decomposition of NH4 HSO4. Abstract: Deactivation by NH4 HSO4 deposition is one of the major problems faced by commercial SCR catalysts at low temperatures. In this study, NH4 NO3 was added to the SCR reaction atmosphere in the presence of H2 O and SO2 at 250 °C, which is lower than the typical temperatures suitable for the V2 O5 -WO3 /TiO2 catalyst. After a long test, the catalyst activity decreased from 82 % to 75 %, which is much smaller than the activity drop in the atmosphere without NH4 NO3 . The characterization results indicate that the addition of NH4 NO3 effectively reduced the deposition of NH4 HSO4 on the catalyst surface, thus weakening the degree of catalyst poisoning deactivation. In addition, we examined the effect of NH4 NO3 addition on the regeneration of catalysts deactivated by NH4 HSO4 . The activity of the catalyst deactivated by 5 wt% NH4 HSO4 recovered efficiently after the deactivated catalyst was treated by NH4 NO3, NO and O2 for 1 h at 250 °C. The SEM, FTIR, and BET characterization results reveal the positive effect of NH4 NO3 in promoting the decomposition of NH4 HSO4 .