Gao Zhengyang, Liu Xiaoshuo, Li Ang, Ma Chuanzhi, Li Xiang, Ding Xunlei, Yang Weijie
School of Energy and Power Engineering, North China Electric Power University, Baoding, 071003, China.
School of Mathematics and Physics, North China Electric Power University, Beijing, 102206, China.
J Mol Model. 2019 May 1;25(5):142. doi: 10.1007/s00894-019-4026-3.
The release of mercury (Hg) species from coal-fired power plants has attracted increasing concern, and the development of an efficient and economical method to control Hg species emission from such plants is urgently required. Activated carbon is a compelling sorbent for the elimination of mercury species from flue gas, but the adsorption mechanism of mercuric oxide clusters on carbonaceous materials is still unclear. Therefore, the adsorption characteristics of mercuric oxide clusters on activated carbon were investigated systematically utilizing density functional theory in this work. It was found that mercuric oxide clusters are chemically adsorbed on activated carbon, and that the pre-adsorption of SO on the activated carbon leads to complicated mercuric oxide cluster adsorption behavior due to an irregular distribution of the electrostatic potential on the surface of the carbonaceous material. Thermodynamic analysis indicated that the adsorption energy of SO on activated carbon is lower than that of mercuric oxide clusters in the temperature range 298.15-1000 K. Competitive adsorption analysis suggested that mercuric oxide clusters are at least 10 times more likely than SO to be adsorbed on activated carbon. Graphical abstract Competitive adsorption between SO and HgO clusters on activated carbon surface in flue gas of coal-fired power plants.
燃煤发电厂汞（Hg）物种的排放引起了越来越多的关注，迫切需要开发一种高效且经济的方法来控制此类电厂汞物种的排放。活性炭是一种用于从烟气中去除汞物种的有吸引力的吸附剂，但氧化汞簇在碳质材料上的吸附机制仍不清楚。因此，本工作利用密度泛函理论系统地研究了氧化汞簇在活性炭上的吸附特性。研究发现，氧化汞簇化学吸附在活性炭上，并且由于碳质材料表面静电势分布不规则，活性炭上SO的预吸附导致氧化汞簇的吸附行为复杂。热力学分析表明，在298.15 - 1000 K温度范围内，SO在活性炭上的吸附能低于氧化汞簇。竞争吸附分析表明，氧化汞簇在活性炭上被吸附的可能性至少比SO高10倍。图形摘要：燃煤发电厂烟气中SO与HgO簇在活性炭表面的竞争吸附。
