晋城高硫煤大分子结构表征及模型构建

Macromolecular structure characterization and its model construction of high-sulfur coal in Jincheng

从分子水平上认识、表征高硫煤的结构特征对于清洁高效利用高硫煤具有关键意义。利用工业元素分析、高分辨率透射电镜、激光解吸飞行时间质谱、13C核磁共振波谱和X射线光电子能谱技术对晋城高硫煤的分子结构进行表征。结果表明:晋城高硫煤中的芳香层片长度分布范围较宽,且以2×2和3×3形式居多;杂原子结构中氮原子以吡啶氮和吡咯氮为主,硫原子的存在形式包含硫醇、硫醚、噻吩、亚砜和砜等多种结构,氧原子主要存在于羟基、羰基、和醚氧中,同时,结构中脂肪侧链长度较短,且支链化程度较低。根据高分辨图像提供的芳香碳骨架信息,从中选取327个芳香层片作为结构模型的基本骨架,在依次实现脂肪结构和杂原子官能团的添加后对其进行优化,得到了与上述实验数据吻合的高硫煤分子结构模型,模型由95个单体分子组成,原子数量为18882个,分子式为C_(12119)H_(6279)O_(214)N_(118)S_(152),分子量为161647Da。通过构建的分子结构模型可应用于进一步研究高硫煤的物理化学性质及反应性等。

To understand and characterize the structure characteristics of high-sulfur coal at molecular level is of key significance for clean and efficient utilization of high-sulfur coal.The molecular structure of Jincheng high-sulfur coal was characterized by proximate analysis,ultimate analysis,high-resolution transmission electron microscopy,laser desorption time of flight mass spectrometry,13C nuclear magnetic resonance spectroscopy and X-ray photoelectron spectroscopy.The results show that the aromatic lamellar length of Jincheng high-sulfur coal has a wide distribution range,and the form of 2×2 and 3×3 is the majority;in the heteroatomic structure,the nitrogen atoms are mainly pyridine nitrogen and pyrrole nitrogen,the sulfur atoms exist in the form of mercaptan,thioether,thiophene,sulfoxide and sulfone structures,and the oxygen atoms mainly exist in the hydroxyl group,carbonyl group,and ether oxygen,and the length of the adipose side chain in the structure is short,the degree of branched chain is low.According to the aromatic carbon skeleton information provided by the high-resolution image,327 aromatic layers were selected as the basic skeleton of the structural model,which was optimized after the addition of aliphatic structure and heteroatomic functional groups in turn.The molecular structure model of high-sulfur coal was obtained in accordance with the above experimental data.The model consists of 95 individual molecules,18882 atoms in total.The molecular formula is C_(12119)H_(6279)O_(214)N_(118)S_(152) and the molecular weight is 161647 Da.The molecular structure model can be applied to further study the physical and chemical properties and reactivity of high-sulfur coal.