Jia Jinzhang, Xing Yinghuan, Li Bin, Wu Yumo, Wang Dongming
College of Safety Science and Engineering, Liaoning Technical University, Fuxin, 123000, China.
Key Laboratory of Mine Thermodynamic disasters and Control of Ministry of Education (Liaoning Technical University), Huludao, 125105, China.
Sci Rep. 2024 Oct 15;14(1):24131. doi: 10.1038/s41598-024-74647-3.
In order to clarify the microscopic dynamics mechanism of CH, CO and HO adsorption and diffusion in coal, and to reveal the mechanism of the influence of different temperatures and pressures on the adsorption and diffusion characteristics of coal adsorbed CH, CO and HO molecules. In this paper, the macromolecular structure model of Jixi gas-fat coal was constructed, based on the Giant Canonical Monte Carlo (GCMC) and Molecular Dynamics (MD) methods. The adsorption-diffusion characteristics of CH,CO and HO single-component gases in the gas-fat coal macromolecule model at temperatures ranging from 273.15 K to 313.15 K and pressures ranging from 0.01 MPa to 15 MPa were investigated by using Material Studio software. The research results indicated that: The adsorption of three gases, CH, CO and HO, increased with the increase of equilibrium pressure, and the adsorption isotherms conformed to Langmuir type I isotherms. The amount of saturated adsorption of CH ranged from 11.18 to 14.37 ml/g, the saturated adsorption of CO ranged from 20.40 to 24.70 ml/g, and the saturated adsorption of HO ranged from 66.61 to 84.21 ml/g. With the increase of temperature, the saturated adsorption of CH and CO both decreased, and the saturated adsorption of HO firstly increased and then decreased, and the adsorption of HO by low temperature and high temperature had both an inhibitory effect on the adsorption of HO. The potential energy distributions of CH, CO and HO molecules are poisson distributed. The absolute values of the most available interaction energies are, from highest to lowest: HO > CO > CH; the activation energies for diffusion of CH, CO and HO are 12.20 kJ/mol, 3.36 kJ/mol, and 8.47 kJ/mol, respectively, and the diffusion of CO is the more likely to occur. The adsorption of CH and CO in coal is physical adsorption, while the adsorption process of HO molecules is beyond the scope of physical adsorption. The absolute value of the interaction energy is HO > CO > CH in descending order.
为阐明CH、CO和HO在煤中的微观动力学吸附扩散机制，揭示不同温度和压力对煤吸附CH、CO和HO分子吸附扩散特性的影响机制。本文基于巨正则蒙特卡罗（GCMC）和分子动力学（MD）方法，构建了鸡西气肥煤的大分子结构模型。利用Material Studio软件研究了CH、CO和HO单组分气体在273.15 K至313.15 K温度范围和0.01 MPa至15 MPa压力范围的气肥煤大分子模型中的吸附扩散特性。研究结果表明：CH、CO和HO三种气体的吸附量均随平衡压力的升高而增加，吸附等温线符合朗缪尔I型等温线。CH的饱和吸附量为11.18至14.37 ml/g，CO的饱和吸附量为20.40至24.70 ml/g，HO的饱和吸附量为66.61至84.21 ml/g。随着温度升高，CH和CO的饱和吸附量均降低，HO的饱和吸附量先升高后降低，低温和高温对HO的吸附均有抑制作用。CH、CO和HO分子的势能分布呈泊松分布。最有效相互作用能的绝对值从高到低依次为：HO＞CO＞CH；CH、CO和HO的扩散活化能分别为12.20 kJ/mol、3.36 kJ/mol和8.47 kJ/mol，CO的扩散更易发生。CH和CO在煤中的吸附为物理吸附，而HO分子的吸附过程超出了物理吸附范畴。相互作用能绝对值由大到小依次为HO＞CO＞CH。
