太原西山西铭8号煤大分子结构构建及甲烷吸附机理研究

发布时间：2018-04-28 06:00

本文选题：西铭8号 + 吸附　；参考：《太原理工大学》2015年硕士论文

【摘要】：随着人类文明的发展煤炭、石油资源的枯竭,能源结构已经从煤石油向天然气转变。我国煤炭资源丰富,探明的煤层气逐年增长。煤层气将成为未来的主要能源。煤层气的生成、储集以及成藏条件与其它天然气有明显的差异。煤层气主要以吸附态赋存于煤层中,所以研究煤与甲烷分子的相互关系,是合理开采煤层气的基础。煤大分子结构具有复杂性和不均一性,煤大分子结构的构建对是研究煤与甲烷分子相互作用的基础。本文利用13C-NMR、FTIR、XPS等物理化学方法,结合工业分析、元素分析,以西山矿区西铭8号煤(XM-8)为例,构建能够反映真实存在形式的煤大分子结构。XM-8模型中,芳香结构单元以菲、葸结构为主,最大环数可达到五个;脂肪结构主要以脂肪侧链的形式存在；氧原子分别以醚键、羟基、和羰基形式存在；氮原子以吡咯和吡啶的形式存在；硫原子以噻吩形式存在。采用Materials Studio6.0(MS)中Forcite模块对XM-8结构模型进行能量最小化模拟。结果表明,分子内及分子间芳香层片之间的π-π相互作用,使其以近似平行的方式排列。在此基础上,根据第一性原理的密度泛函理论,计算并研究了甲烷与XM-8大分子结构的相互作用及最优吸附位置,并与石墨模型进行了比较。结果表明：甲烷分子在煤大分子芳香环结构中2-Bond-UP位置为最优吸附位置,吸附能为-38.37 kJ/mol甲烷分子在煤大分子杂原子环结构中C-C键或X-C键中间为最优吸附,并且优先吸附在芳香环结构上。径向分布函数表明,煤大分子结构对甲烷的吸附作用是由吸附位置与吸附方向共同决定的,并且甲烷的吸附位点与吸附方向的差异所引起的吸附能变化大于芳香结构单元对其的影响。
[Abstract]:With the development of human civilization and the depletion of petroleum resources, the energy structure has changed from coal oil to natural gas. China is rich in coal resources and the proven coalbed methane is increasing year by year. Coalbed methane will be the main energy source in the future. The formation, reservoir and reservoir conditions of CBM are obviously different from those of other natural gas. Coal-bed methane mainly exists in coal bed by adsorption, so the study of the interrelation between coal and methane molecules is the basis of rational exploitation of coalbed methane. The structure of coal macromolecule is complex and heterogeneous. The construction of coal macromolecular structure is the basis of studying the interaction between coal and methane. In this paper, by means of physical and chemical methods such as 13C-NMR-FTIRX XPS, combined with industrial analysis and elemental analysis, taking Ximing No. 8 coal mine in Xishan mining area as an example, a model of coal macromolecular structure .XM-8, which can reflect the true existence of coal, is constructed. The aromatic structure unit is phenanthrene, and the aromatic structure unit is phenanthrene. The main structure is anthracene, the maximum number of rings is five, the fat structure is mainly in the form of adipose side chain, the oxygen atom exists in the form of ether bond, hydroxyl group and carbonyl group, the nitrogen atom exists in the form of pyrrole and pyridine, respectively. Sulfur atoms exist in the form of thiophene. The Forcite module in Materials Studio 6.0 is used to simulate the energy minimization of the XM-8 structure model. The results show that the 蟺-蟺 interaction between the intramolecular and intermolecular aromatic lamellae makes it arranged in an approximate parallel manner. Based on the first principle density functional theory, the interaction between methane and XM-8 macromolecular structure and the optimal adsorption site are calculated and studied. The results are compared with the graphite model. The results show that the 2-Bond-UP position of methane molecule in the aromatic ring structure of coal macromolecule is the optimal adsorption position, and the adsorption energy is -38.37 kJ/mol methane molecule adsorbed in the C-C bond or X-C bond between the C-C bond and X-C bond in the heteratomic ring structure of coal macromolecule. And preferentially adsorbed on the aromatic ring structure. The radial distribution function shows that the adsorption of methane by coal macromolecular structure is determined by the adsorption position and the adsorption direction. The adsorption energy change caused by the difference of adsorption site and direction of methane is larger than that of aromatic structure unit.
【学位授予单位】：太原理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P618.1

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