Zhu Benkang, Dong Xianshu, Fan Yuping, Ma Xiaomin, Yao Suling, Fu Yuanpeng, Chen Ruxia, Chang Ming
Department of Mineral Processing Engineering, Taiyuan University of Technology, Taiyuan 030024, China.
State Key Laboratory of Mineral Processing, Beijing 100160, China.
Molecules. 2023 Jul 23;28(14):5593. doi: 10.3390/molecules28145593.
High-ash coal, also known as low-grade coal, has becomes a viable alternative in recent years to high-quality coal because available resources have become increasingly scarce due to extensive mining activity. This work aims to provide a comprehensive understanding of the structural characteristics of high-ash coal and construct a plausible molecular structure to elucidate its chemical reactivity in future applications. Its properties were investigated using Solid-state C nuclear magnetic resonance (C NMR), X-ray photoelectron spectroscopy analysis (XPS), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FT-IR). The molecular structure was constructed and validated using Material Studio, LAMMPS Software Package, and MATLAB program. The characterization results revealed that high-ash coal contains 72.15% aromatic carbon, significantly surpassing the percentage of aliphatic carbon (27.85%). The ratio of bridgehead carbon to peripheral aromatic carbon was calculated as 0.67, indicating that the pentacene is the main carbon skeleton form in the high-ash coal structure. Furthermore, oxygen-containing functional groups presented as C=O/O-C-O, C-O, and COO- within the structure along with pyridine and pyrrolic structures. Consequently, the molecular structure comprises pentacene with aliphatic carbon chains, such as methylene, that connect the benzene rings and form a three-dimensional network. The results of a simulated IR spectrum and contact angle simulation aligned with the experimental results, validating the molecular structure of high-ash coal. The chemical formula for the high-ash coal model was determined as CHNOS with a molecular weight of 3734.79.
高灰分煤，也被称为低品位煤，近年来已成为优质煤的一种可行替代品，因为由于广泛的开采活动，可用资源日益稀缺。这项工作旨在全面了解高灰分煤的结构特征，并构建一个合理的分子结构，以阐明其在未来应用中的化学反应性。使用固态碳核磁共振（C NMR）、X射线光电子能谱分析（XPS）、X射线衍射（XRD）和傅里叶变换红外光谱（FT-IR）对其性质进行了研究。使用Material Studio、LAMMPS软件包和MATLAB程序构建并验证了分子结构。表征结果表明，高灰分煤含有72.15%的芳香碳，大大超过脂肪族碳的百分比（27.85%）。桥头碳与周边芳香碳的比例计算为0.67，表明并五苯是高灰分煤结构中的主要碳骨架形式。此外，结构中存在以C=O/O-C-O、C-O和COO-形式存在的含氧官能团以及吡啶和吡咯结构。因此，分子结构由并五苯与脂肪族碳链（如亚甲基）组成，这些碳链连接苯环并形成三维网络。模拟红外光谱和接触角模拟的结果与实验结果一致，验证了高灰分煤的分子结构。高灰分煤模型的化学式确定为CHNOS，分子量为3734.79。
