Abstract

This study aims to investigate the molecular structure of Yangchangwan (YCW) subbituminous coal using state-of-the-art, multi-scale computer-aided modeling methods and several chemical/physical techniques, such as proximate analysis and chemical composition analysis, FT-IR, ¹³C NMR, and XPS analyses. Based on the characterizations obtained, pivotal information concerning the elements and chemical bonding in the structure of the coal is obtained. The results reveal that the content of aromatic carbon of the YCW coal is 71.33%. The ratio of aromatic bridge carbon to peripheral carbon in the YCW coal is 0.32, indicating that the proportion of naphthalene in the coal structure is higher than that of anthracene and benzene. Oxygen mainly exists in the form of carbonyl, ether and carboxyl functional groups. Nitrogen is present as both pyridine and pyrrole. Methyne group is mostly in cyclic and aliphatic hydrocarbons. The single molecular formula of YCW coal is founded as C₃₂₃H₂₃₂O₄₂N₄S, which is attained using the average molecular structure according to the structural information obtained. Two- and three-dimensional molecular models of the YCW coal are built via multi-scale molecular modeling. The model is optimized and further confirmed by spectra simulation produced by QM calculations. Thus, this study illustrates the molecular structure and provides an understanding of the YCW coal at the atomic level through experimental and multi-scale computational descriptions.

中文翻译：

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基于实验和多尺度计算描述相结合的羊场湾次烟煤分子结构洞察

摘要

本研究旨在利用最先进的多尺度计算机辅助建模方法和多种化学/物理技术，如近似分析和化学成分分析、FT-红外，¹³C NMR 和 XPS 分析。基于获得的表征，获得了有关煤结构中元素和化学键的关键信息。结果表明，YCW煤的芳烃碳含量为71.33%。YCW煤中芳桥碳与外围碳的比例为0.32，表明萘在煤结构中的比例高于蒽和苯。氧主要以羰基、醚和羧基官能团的形式存在。氮以吡啶和吡咯的形式存在。次甲基主要存在于环状和脂肪烃中。YCW煤的单一分子式为C ₃₂₃ H ₂₃₂ O ₄₂ N ₄S，这是根据获得的结构信息使用平均分子结构获得的。YCW煤的二维和三维分子模型是通过多尺度分子建模建立的。该模型通过 QM 计算产生的光谱模拟得到优化和进一步证实。因此，本研究通过实验和多尺度计算描述说明了分子结构，并在原子水平上提供了对 YCW 煤的理解。