成庄无烟煤大分子结构模型及其分子模拟

利用晋城矿区成庄矿煤的工业分析、元素分析、¹³C-NMR、XPS等实验结果,构建了其大分子结构模型.模型中,芳香碳以2、3、4环结构为主,最大环数达五个;脂肪碳以甲、乙基侧链及环烷烃的形式存在.九个氧原子分别以七个羰基(主要为醌基)、一个羟基及一个醚氧的型式存在;两个氮原子以吡咯的形式存在.硫原子含量很低,在模型构建中没有体现.采用分子力学(MM)和分子动力学(MD)方法,对成庄煤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;高煤级煤结构中,短程有序的原因主要是分子间芳香层片的定向排列.分子间的氢键能及范德华能使结构达到最稳构型.

Construction of macromolecular structural model of anthracite from Chengzhuang coal mine and its molecular simulation

The macromolecular structure model of Chengzhuang coal was constructed based on the results of proximate and ultimate analysis, ¹³C-NMR spectrum and XPS spectrum. In the model the numbers of rings in polycyclic aromatic hydrocarbon were distributed between 1 and 5. The aliphatic C atoms existed in the forms of -CH₃,-CH₂- and cycloalkanes. 9 atoms of O were in the form of C=O, while one in the form of -OH and another one in the form of -O-. 2 atoms of N were in pyrrole, while S atom did not appear in the model because its concentration was lower than 1%. Molecular mechanics (MM) and molecular dynamics (MD) was adopted to simulate the energy-minimum conformation of the model and the results showed that the aromatic layers tended to be parallel by intramolecular or intermolecular π-π interaction and the latter should be one of the main contributors for the short-range ordering of high-rank coal structure. The van der waals energy and hydrogen bond energy contributed to the energy-minimum conformation.