Emission factors of mercury and particulate matters, and in situ control of mercury during the co-combustion of anthracite and dried sawdust sludge. (15th October 2018)

• Record Type: Journal Article
• Authors: Hao, Runlong; Yang, Fan; Mao, Xingzhou; Mao, Yumin; Zhao, Yi; Lu, Yuejiang
• Is Part Of: Fuel. Volume 230(2018)
• Page Start: 202
• Page End: 210
• Publication Date: 2018-10-15
• Subjects: Anthracite -- Dried sawdust sludge -- Mercury emission -- PMs emission -- Hg0 control; Fuel -- Periodicals; Coal -- Periodicals; Coal; Fuel; Periodicals; 662.6
• DOI: 10.1016/j.fuel.2018.05.026
• Languages: English
• ISSNs: 0016-2361

Abstract

Graphical abstract: Highlights: The Hg 0 emission factors in the co-combustion of anthracite and DSS were determined. The fly ash yield in co-combustion process was determined by the DSS proportion. The in situ control of Hg 0 was tried by two useful methods. The removal products of Hg 0 were identified as HgSO4 and HgX2 by XPS. Abstract: Anthracite and dried sawdust sludge (DSS) were demonstrated as a complementary combination. Since air pollution has attracted great concern, this paper studies the emission characteristics of mercury and particulate matters (PMs) during the co-combustion process. The results indicated that no Hg 2+ was produced in all cases. The Hg 0 emission factor decreased significantly with the increasing of DSS. The rising temperature from 800 to 900 °C slightly promoted the Hg 0 emission, but the further increasing temperature caused a decreasing of Hg 0 emission. Oxygen-enrich atmosphere accelerated the release of Hg 0 from anthracite, but the DSS combustion was independent on the atmospheric conditions. The emission factor of PMs for DSS was 10.5 ± 1.7 mg/kg which was 9 times higher than that of anthracite combustion (95.2 ± 7.7 mg/kg). The results of in situ control of Hg 0 demonstrated the co-combustion of fuel and Ca-based additives could not deeply reduce Hg 0 emission, however the integrated approach of gas phase oxidation combined with wet absorption was satisfactory in terms of Hg 0 control, and the way of post-combustion injection was better, the oxidation efficiencies of Hg 0 reached 62.5%. The main existing forms of mercury were determined as HgSO4 and HgX2 (X: Br or Cl) by XPS, the reaction mechanism of Hg 0 removal was proposed accordingly.