摘要
煤的复杂性和不均一性使其分子结构研究一直充满挑战。近年来,分子模拟技术在国内被广泛用于煤分子结构表征,包括性质不同的镜质组和惰质组分子结构。这2种组分是构成煤的主要成分,从分子层面研究二者的结构差异有助于推动开发贴近煤真实结构的分子模型。文中从成分、化学结构、分子模拟等方面分析了基于计算化学构建的煤的镜质组和惰质组分子模型。通过对比分析发现,与惰质组相比,镜质组中的碳、氢原子数量多,多数情况下氧原子的数量偏高;芳香碳数量少,芳香结构缩合程度低;二者脂肪结构的存在方式相似,以链状、环状脂肪结构存在,但镜质组长度、支链数量一般高于惰质组;杂原子存在形式也相似,但镜质组中的碳氧双键数量一般略高于惰质组,碳氧单键数量多数情况下略低于惰质组。经过分子模拟优化后的模型,分子结构发生了扭曲变形,总能量降低,但惰质组的总势能高于镜质组,分子排列更紧密。当前的分子模型在一定程度上能反映出二者的分子结构差异,但还难以描述二者的真实化学结构,构建一定分子量分布的多组分模型组成的镜质组和惰质组分子模型值得研究。
The complexity and heterogeneity of coal have been posing challenges to the research on its molecular structure.In recent years,molecular simulation technology has been extensively applied to the molecular representation of Chinese coal,including the molecular structures of vitrinite and inertinite with different properties,which are the main constituents of coal.Studying the structural differences between them at the molecular level helps promote the development of chemical structure models that are close to the real structure of coal.This paper analyzed the molecular models of vitrinite and inertinite of coal based on computational chemistry from composition,chemical structure,and molecular simulation.Through comparative analysis,it was found that compared with inertinite,the number of carbon and hydrogen atoms in vitrinite is greater,and in most cases,the number of oxygen atoms is also greater;the number of aromatic carbons is smaller,and the degree of condensation of the aromatic structure is lower;the forms of the aliphatic structures of both are similar,in the form of chain and cyclic aliphatic structures,but the length and number of branches in vitrinite are generally higher than in inertinite;The forms of heteroatoms are also similar,though vitrinite generally has slightly more carbon-oxygen double bonds and,in most cases,slightly fewer carbon-oxygen single bonds than inertinite.After optimization via molecular simulation,the molecular structures undergo distortion,with total energy decreasing.However,inertinite exhibits higher total potential energy and tighter molecular packing than vitrinite.Current molecular models can,to some extent,reflect the structural differences between the two components,but accurately describing their true chemical structures remains challenging.Further research is warranted to develop multi-component models with a certain molecular weight distribution to represent vitrinite an d inertinite more comprehensively.
作者
徐申
于秀明
孙东明
范雪健
战丽
Xu Shen;Yu Xiuming;Sun Dongming;Fan Xuejian;Zhan Li(Zhongwei Coking Technology National Engineering Research Ce nter Co.,Ltd.,Anshan 114000,China;Sinosteel Anshan Research Institute of Thermo-Energy Co.,Ltd.,Anshan 114044,China;College of Chemical Engineering,University of Science and Technology,Anshan 114051,China)
出处
《燃料与化工》
2025年第5期6-11,29,共7页
Fuel & Chemical Processes
基金
辽宁省自然科学基金项目,2019-ZD-0896基于煤岩显微组分研究煤在制备多孔炭材料过程中结构的演变机制。
