Indexed by:Journal Article

Date of Publication:2017-09-01

Journal:FUEL

Included Journals:Scopus、EI、SCIE

Volume:203

Page Number:308-315

ISSN:0016-2361

Key Words:Element mercury removal; SO2 poisoning; Ce-0.1-Zr-Mn; Adsorption; Oxidation

Abstract:The removal of Hg-0 from flue gas has been one of the primary challenges in the control of mercury emission. The presence of even small amounts of SO2 has a significant influence on the Hg-0 removal process, and the mechanism of this process has not been thoroughly explained to date. To understand the mechanism for SO2 influence, the influence of SO2 on the Hg0 adsorption and Hg-0 oxidation components of the Hg-0 removal process were investigated separately based on Ce-0.1-Zr-MnO2 center dot SO2 was shown to have serious negative effects on the Hg-0 adsorption process due to the reaction between SO2 and Mn-based active sites, as determined by TGA and XPS results. In contrast, for the Hg0 oxidation process Mn-SO42 formed through the reaction between SO2 and Mn-based active sites, and Mn-SO42 had a certain contribution to Hg-0 oxidation. Moreover, XPS results indicated that SO2 reacts with O-2 to form SO3 which adsorbed on the catalyst surface and act as new active sites, promoting Hg-0 oxidation via: Hg + SO3 + 1/2O(2) -> HgSO4. This phenomenon caused the catalyst to retain Hg-0 oxidation activity in the presence of SO2 for a relatively long time. (C) 2017 Elsevier Ltd. All rights reserved.