基于蒙特卡洛方法的煤吸附水机理

发布时间：2018-03-25 21:46

本文选题：水　切入点：煤　出处：《煤炭学报》2017年11期

【摘要】：为研究煤对水的吸附机理,建立煤大分子结构模型,采用巨正则系综蒙特卡洛方法,在分子尺度研究分析了压力1~100 k Pa不同温度下水在煤中的吸附行为,为涉及煤水相互作用的进一步研究奠定理论基础。结果表明:水的吸附量和等量吸附热与温度负相关,与压力正相关。在大于临界压力的某一压力下,两吸附位的势能概率分布间形成高原区,说明比例相当。超过该压力,相互作用更强的氢键占主要地位,吸附量开始急剧增大,发生毛细凝聚,形成水团簇。随着压力增大,吸附继续由较弱的H_2O-煤相互作用的吸附位向较强的H_2O-H_2O相互作用的吸附位移动,直至全部作用在由已吸附的H_2O形成的第2吸附位,等量吸附热趋于平稳。得到了水在煤中吸附过程概率密度的三维分布,从而更直观全方位地认识水的吸附行为及机理。
[Abstract]:In order to study the adsorption mechanism of coal to water and to establish a model of macromolecular structure of coal, the adsorption behavior of water at different temperatures at 1 ~ 100 KPA was studied on a molecular scale by using the grand canonical ensemble Monte Carlo method. The results show that the adsorption capacity and heat of adsorption of water are negatively correlated with temperature and positive correlation with pressure. The probability distribution of the potential energy of the two adsorption sites forms a plateau region, indicating that the proportion is equal. When the pressure exceeds this pressure, the hydrogen bond with stronger interaction occupies the main position, and the adsorption amount increases sharply, the capillary condensation occurs, and the water cluster is formed. The adsorption continued to move from the weaker adsorption site of H _ 2O-coal interaction to the adsorption site of stronger H_2O-H_2O interaction until the second adsorption site formed by the adsorbed H _ 2O, The isobaric adsorption heat tends to be stable, and the three-dimensional distribution of the probability density of water adsorption process in coal is obtained, so that the adsorption behavior and mechanism of water can be understood more intuitively and comprehensively.
【作者单位】：辽宁工程技术大学安全科学与工程学院;山西焦煤集团有限责任公司;辽宁工程技术大学安全工程技术研究院;
【基金】：国家自然科学基金资助项目(51174108,51774172)
【分类号】：O647.3;TQ530

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