School of Renewable Energy , North China Electric Power University , Beijing 102206 , China.
Key Laboratory of Thermal Science and Power Engineering of Ministry of Education, Department of Thermal Engineering , Tsinghua University , Beijing 100084 , China.
Environ Sci Technol. 2018 Mar 6;52(5):2981-2987. doi: 10.1021/acs.est.7b06020. Epub 2018 Feb 20.
This paper discussed the field test results of mercury oxidation activities over vanadium and cerium based catalysts in both coal-fired circulating fluidized bed boiler (CFBB) and chain grate boiler (CGB) flue gases. The characterizations of the catalysts and effects of flue gas components, specifically the particulate matter (PM) species, were also discussed. The catalytic performance results indicated that both catalysts exhibited mercury oxidation preference in CGB flue gas rather than in CFBB flue gas. Flue gas component studies before and after dust removal equipment implied that the mercury oxidation was well related to PM, together with gaseous components such as NO, SO, and NH. Further investigations demonstrated a negative PM concentration-induced effect on the mercury oxidation activity in the flue gases before the dust removal, which was attributed to the surface coverage by the large amount of PM. In addition, the PM concentrations in the flue gases after the dust removal failed in determining the mercury oxidation efficiency, wherein the presence of different chemical species in PM, such as elemental carbon (EC), organic carbon (OC) and alkali (earth) metals (Na, Mg, K, and Ca) in the flue gases dominated the catalytic oxidation of mercury.
本文讨论了在燃煤循环流化床锅炉（CFBB）和链条炉排锅炉（CGB）烟气中，基于钒和铈的催化剂的汞氧化活性的现场测试结果。还讨论了催化剂的特性以及烟气成分（特别是颗粒物（PM）种类）的影响。催化性能结果表明，两种催化剂在 CGB 烟气中均表现出优于 CFBB 烟气的汞氧化性能。除尘设备前后的烟气成分研究表明，汞氧化与 PM 以及气态成分（如 NO、SO 和 NH）密切相关。进一步的研究表明，在除尘之前，PM 浓度的降低对烟气中的汞氧化活性产生负面影响，这归因于大量 PM 对表面的覆盖。此外，除尘后烟气中的 PM 浓度无法确定汞氧化效率，因为 PM 中存在不同的化学物质，如元素碳（EC）、有机碳（OC）和碱（土）金属（Na、Mg、K 和 Ca）在烟气中主导了汞的催化氧化。
