Influence of unburned carbon on mercury chemical forms in fly ash produced from a coal-fired power plant

FUEL

卷:300

Article

Uaciquete, Dorcas L. E.¹  Sakusabe, Kosuke¹  Kato, Takahiro¹  Okawa, Hirokazu¹  Sugawara, Katsuyasu¹  Nonaka, Risehiro² 

[1] Akita Univ, Grad Sch Engn Sci, 1-1 Tegata Gakuen Machi, Akita 0108502, Japan

[2] Akita Coll, Natl Inst Technol, 1-1 Iijimabunkyocho, Akita 0118511, Japan

关键词: Coal;    Mercury;    Chemical forms;    Fly ash;   

DOI  :  10.1016/j.fuel.2021.120802

来源: Elsevier

【 摘 要 】

The chemical forms of mercury in coal-fired power plant fly ash were determined qualitatively and quantitatively using X-ray absorption near edge structure (XANES) analysis. Mercury content in the fly ash increased linearly with an increase in the content of unburned carbon. The inflection point method, using the first and second derivatives of XANES spectra, was used to estimate the type and abundance of chemical forms present. The XANES spectrum of fly ash mercury was modeled by a linear combination fitting of control mercury compounds, with their abundance ratios used as fitting parameters. The inflection point difference in energy was used as the requirements for simulation. The fly ash sample contained 2.6 ppm of mercury which combined with sulfur, chlorine and oxygen. The determined abundance ratios of C-Hg-S, C-Hg-Cl and C-Hg-O were 18, 27 and 36%, respectively. The unburned carbon in the fly ash was impregnated with sulfur and exposed to gaseous mercury oxide. The amount of captured mercury increased dramatically with the increase in sulfur content while chlorine and oxygen in the unburned carbon also influenced on the mercury chemical forms.

【 授权许可】

Free