弥勒褐煤结构特征及其分子模型构建  

Structural characteristics of Mile lignite and its molecular model construction

作　　者：张殿凯 李艳红[1,2] 常丽萍[2] 訾昌毓 张远琴 田国才[3] 赵文波[1] ZHANG Dian-kai;LI Yan-hong;CHANG Li-ping;ZI Chang-yu;ZHANG Yuan-qin;TIAN Guo-cai;ZHAO Wen-bo(School of Chemical Engineering,Kunming University of Science and Technology,Kunming 650500,China;State Key Laboratory Breeding Base of Coal Science and Technology Co-founded by Shanxi Province and Ministry of Science and Technology,Taiyuan University of Technology,Taiyuan 030024,China;State Key Lab of Complex Nonferrous Metal Resource Clean Utilization,Kunming University of Science and Technology,Kunming 650093,China)

机构地区：[1]昆明理工大学化学工程学院,云南昆明650500 [2]太原理工大学煤科学与技术省部共建国家重点实验室培育基地,山西太原030024 [3]昆明理工大学省部共建复杂有色金属资源清洁利用国家重点实验室,云南昆明650093

出　　处：《燃料化学学报》2021年第6期727-734,共8页Journal of Fuel Chemistry and Technology

基　　金：国家自然科学基金(21766013);昆明理工大学分析测试基金(2020M20192208021)资助。

摘　　要：以云南弥勒褐煤为研究对象,采用元素分析、傅里叶变换红外光谱、^(13)C固体核磁共振波谱以及X射线光电子能谱等现代分析技术,获取了弥勒褐煤的结构参数信息。其中,芳香度为38.79%,芳香环取代基数量为3。芳香碳结构主要为苯和萘,脂肪碳结构以甲基、亚甲基为主;氧主要存在于醚氧、羧基和羰基中;氮主要以吡咯氮和吡啶氮的形式存在;硫主要为硫酚或硫醇。根据分析结果,构建出弥勒褐煤的分子结构模型,分子式为C_(147)H_(148)O_(36)N_(2)S。采用半经验法PM3基组和密度泛函理论M06-2X泛函对分子构型进行优化,优化后的模型立体构型显著,且芳香层片在空间上呈现不规则排列,各芳香环之间主要通过甲基、亚甲基、甲氧基以及脂肪环连接。模拟FT-IR光谱和模拟^(13)C NMR波谱均与实验谱图吻合良好,证明了弥勒褐煤分子模型的准确性和合理性。The understanding of the structural characteristics of lignite is of very importance to the lignite utilization.The structure parameters of Mile lignite in Yunnan were ascertained via Fourier transform infrared spectroscopy,^(13)C solid-state nuclear magnetic resonance spectroscopy,X-ray photoelectron spectroscopy and ultimate analysis.The results indicate that the aromaticity and number of aromatic ring substituents of Mile lignite are 38.79%and 3,respectively.The aromatic carbon structure typically contains benzene and naphthalene,while the aliphatic carbon structure mainly includes methyl and methylene.Oxygen dominantly exists in ether oxygen,carboxyl and carbonyl;nitrogen occurs in the form of pyrrole nitrogen and pyridine nitrogen;and sulfur is mainly present in thiophenol and mercaptan.According to the analysis results,a molecular structure model of Mile lignite is constructed,with a molecular formula of C_(147)H_(148)O_(36)N_(2)S.The semi-empirical PM3 basis set and the density functional theory M06-2X were adopted to optimize the molecular configuration.The optimized model has a significant three-dimensional configuration,in which the aromatic layers are arranged irregularly in space and the aromatic rings are connected by methyl,methylene,methoxy and alicyclic rings.The simulated FT-IR spectrum and simulated ^(13)C NMR spectrum are in great agreement with the experimental spectrum,which proves the accuracy and rationality of the molecular model of Mile lignite.

关 键 词：褐煤 分子模拟 分子结构 量子化学计算 结构优化 

分 类 号：TQ531[化学工程—煤化学工程]