Effect of Nitrogen Oxides on Elemental Mercury Removal by Nanosized Mineral Sulfide

Hailong Li, Lei Zhu, Jun Wang, Liqing Li, Po Heng Lee, Yong Feng, Kaimin Shih

Research output: Journal article publicationJournal articleAcademic researchpeer-review

53 Citations (Scopus)

Abstract

Because of its large surface area, nanosized zinc sulfide (Nano-ZnS) has been demonstrated in a previous study to be efficient for removal of elemental mercury (Hg0) from coal combustion flue gas. The excellent mercury adsorption performance of Nano-ZnS was found to be insusceptible to water vapor, sulfur dioxide, and hydrogen chloride. However, nitrogen oxides (NOX) apparently inhibited mercury removal by Nano-ZnS; this finding was unlike those of many studies on the promotional effect of NOXon Hg0removal by other sorbents. The negative effect of NOXon Hg0adsorption over Nano-ZnS was systematically investigated in this study. Two mechanisms were identified as primarily responsible for the inhibitive effect of NOXon Hg0adsorption over Nano-ZnS: (1) active sulfur sites on Nano-ZnS were oxidized to inactive sulfate by NOX; and (2) the chemisorbed mercury, i.e., HgS, was reduced to Hg0by NOX. This new insight into the role of NOXin Hg0adsorption over Nano-ZnS can help to optimize operating conditions, maximize Hg0adsorption, and facilitate the application of Nano-ZnS as a superior alternative to activated carbon for Hg0removal using existing particulate matter control devices in power plants.
Original languageEnglish
Pages (from-to)8530-8536
Number of pages7
JournalEnvironmental Science and Technology
Volume51
Issue number15
DOIs
Publication statusPublished - 1 Aug 2017

ASJC Scopus subject areas

  • Chemistry(all)
  • Environmental Chemistry

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