高硫肥煤碳结构研究与光谱学表征

Spectroscopic Characterization of Carbon Structure in High Sulfur Fat Coal

煤结构是煤化学的重要研究内容,优质肥煤在我国属于稀缺炼焦煤种。碳是煤结构的基本骨架,是构成煤中有机质及形成焦炭的主要元素。研究高硫肥煤中的碳结构对认知肥煤结构与性质,提高低品质炼焦煤利用效率具有重要意义。采集并制备山东东滩(DT)和山西水峪(SY)、霍州(HZ)、高阳(GY)四个矿区的肥煤样品,利用X-射线衍射(XRD)、傅里叶变换红外光谱(FTIR)以及X-射线光电子能谱(XPS)对煤中碳结构进行谱学表征和联合解析,结合煤质分析结果,计算不同肥煤样品的碳结构参数。研究结果表明:SY,HZ,GY和DT四种肥煤的芳香度fa-XRD依次增大,芳香层片的延展度L c和堆垛高度L a依次减小,山西煤的芳香碳结构层片在排列规整度和芳香环缩合程度上强于东滩煤。DT和GY煤中芳香烃结构主要以苯环五取代、苯环四取代和苯环三取代形式存在,SY与HZ煤中芳香结构以苯环二取代和苯环四取代为主。DT和GY煤含有较多的支链和较高的芳环缩合度。四种肥煤中脂肪结构均是以亚甲基为主,DT,SY,HZ和GY煤的亚甲基占脂肪结构的比例分别为46.27%,48.89%,44.21%和41.85%,煤中含有较多的烷基侧链。GY与DT煤中甲基含量略高于次甲基,SY和HZ煤则相反,这主要与不同煤样在成烃期间长脂肪族结构发生断裂的程度有关。SY,HZ,GY和DT煤的芳碳率分别为0.83,0.81,0.74和0.68,芳氢率分别为0.51,0.43,0.34和0.29,煤中芳构化程度依次减小,芳香环缩合度依次升高。DT和HZ煤的氧化程度较高,DT煤含有较多的C—O结构,判断DT煤中存在较多不易被热分解或不易起化学反应的非活性氧。

Coal structure is an important research content of coal chemistry.High-quality fat coal is a scarce coking coal type in China.Carbon is the basic skeleton of the coal structure.Carbon is the basic skeleton of coal structure.It is the main element that forms organic matter in coal and forms coke.Study the carbon structure in high sulfur fat coal is of great significance for understanding the structure and properties of fertile coal,improving the utilization efficiency of low-quality coking coal.Collected and prepared the coal samples from Shandong Dongtan(DT),Shanxi Shuihu(SY),Huozhou(HZ),and Gaoyang(GY)mining areas.The carbon structure in coal was characterized and analyzed by XRD,FTIR and XPS.Combined with coal quality analysis results to calculate the carbon structure parameters of different coal samples.The research results show that the fa-XRD of SY,HZ,GY,DT increases sequentially.Lcand La decrease in order.The aromatic carbon structure of Shanxi coalsis stronger than Dongtan coal in arrangement regularity and aromatic ring condensation.The aromatic hydrocarbon structures in DT and GY coal exist mainly in the form of benzene ring penta-substitution,benzene ring tetra-substitution and benzene ring tri-substitution.The aromatic structure in SY and HZ coal is dominated by benzene ring disubstitution and benzene ring tetra substitution.DT and GY coals contain more branches and higher degrees of aromatic ring condensation.The fat structure of the four kinds of fat coal is dominated by methylene.The proportions of methylene groups in DT,SY,HZ,GY coal to the fat structure were 46.27%,48.89%,44.21%,41.85% respectively.Coal contains more alkyl side chains.GY and DT coal have slightly higher methyl content than methine,while SY and HZ coal have the opposite.It is mainly related to the degree of fracture of the long aliphatic structure of different samples during hydrocarbon generation.The aromatic carbon ratios of SY,HZ,GY,DT coal are 0.83,0.81,0.74,0.68 respectively and aromatic hydrogen ratios are 0.51,0.43,0.34,0.29 respectively.The degree of aromatization in coal decreases in turn.The aromatic ring condensation degree increases in order.The oxidation degree of DT and HZ coal is high.DT coal contains C—O structure,and it is judged that there is more inactive oxygen in coal which is not easily decomposed by heat or chemical reaction.