不同煤阶煤分子表面吸附水分子的机理

发布时间：2018-03-11 05:15

本文选题：煤结构　切入点：吸附水　出处：《煤炭学报》2017年03期 　论文类型：期刊论文

【摘要】：采用量子化学方法中包含色散矫正的密度泛函理论(DFT-D3),对4种不同煤阶(无烟煤、烟煤、次烟煤、褐煤)的煤分子表面吸附水分子的微观机理进行研究。通过优化煤分子表面吸附水分子的平衡构型,对煤分子表面进行静电势分析,计算相互作用能,并通过约化密度梯度(RDG)判断水分子在不同煤阶煤分子表面的作用类型。研究表明,煤分子与水分子间最大相互作用能为-11.91 kcal/mol,煤吸附水的过程属于物理吸附,且相互作用能的大小由弱相互作用力的类型和作用力个数共同决定。褐煤具有较大静电势的分子表面积最多,褐煤更易与极性水分子形成相互作用。4种不同煤阶煤分子吸附水分子的最大相互作用能大小顺序为:褐煤次烟煤烟煤无烟煤。各煤阶最大相互作用能对应的平衡吸附构型下煤分子与水分子的作用类型依次为:范德华作用力,氢键作用,氢键与范德华作用力的共同作用,两个氢键的共同作用。
[Abstract]:The density functional theory (DFT), which includes dispersion correction in quantum chemical methods, is used to study four kinds of coal rank (anthracite, bituminous coal, subbituminous coal). By optimizing the equilibrium configuration of the adsorbed water molecules on the coal molecular surface, the electrostatic potential of the coal molecular surface is analyzed and the interaction energy is calculated. The maximum interaction energy between coal molecules and water molecules is -11.91 kcal / mol, and the process of water adsorption belongs to physical adsorption, according to the reduced density gradient (RDGG) of the coal molecules acting on the surface of different coal rank coal molecules, and the results show that the maximum interaction energy between coal molecules and water molecules is -11.91 kcal / mol. The interaction energy is determined by the type and number of the weak interaction forces. Lignite is more likely to interact with polar water molecules. 4 the order of maximum interaction energy of absorbent water molecules of different rank coal is: bituminous bituminous coal bituminous coal bituminous coal. Equilibrium of maximum interaction energy of each coal rank. The types of interaction between coal molecules and water molecules under adsorption configuration are as follows: van der Waals force, The interaction between hydrogen bond and van der Waals force, and the interaction between two hydrogen bonds.
【作者单位】：华北电力大学能源动力与机械工程学院;
【基金】：中央高校基本科研业务费专项资金资助项目(10MG19)
【分类号】：TQ530;O647.3

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