Abstract:

A four-carbon ring thiophene cluster model for characterizing petroleum coke surface was established. The B3LYP-D3 method of quantum chemical density functional theory was used to study the bromide oil from the microscopic level based on the 6-31g(d)/lanl2dz mixed basis set level. The reaction pathways of HgBr and HgBr₂ on the surface of brominated petroleum coke, the activation energy required for the reaction, the adsorption energy, and the Mayer bond orders were given. The synergistic effect of thiophene sulfur in petroleum coke and the bromine in mercury removal was revealed. The results show that Hg⁰ is mainly oxidized to HgBr on brominated petroleum coke and more bromine loading can both enhance the stability of adsorption and promote the occurrence of chemical adsorption. Thiophene sulfur does not directly participate in the oxidation reaction, but it can help to stably carry more bromine, thereby improving the efficiency of mercury removal.

Key words: coal combustion, mercury, brominated petroleum coke, thiophene sulfur, adsorption, computational chemistry

摘要：

建立了表征石油焦表面的四碳环并噻吩簇模型，运用量子化学密度泛函的B3LYP-D3方法，基于6-31g （d）/lanl2dz混合基组水平，从微观层面研究了溴化石油焦吸附并氧化Hg⁰的机理，给出了HgBr和HgBr₂在溴化石油焦表面的反应路径、反应所需活化能、吸附能以及相关Mayer键级，指出了石油焦中噻吩硫与负载的溴在脱汞中的协同作用。研究结果表明，Hg⁰在溴化石油焦上的氧化物的形式以HgBr为主，更多的溴原子既可以增强吸附的稳定性又能促进化学吸附的发生。噻吩硫不直接参与氧化反应，但可以帮助石油焦稳定地负载上更多的溴，进而提高脱汞的效率。

关键词: 煤燃烧, 汞, 溴化石油焦, 噻吩硫, 吸附, 计算化学