煤液化沥青分析表征及结构模型

对从煤液化残渣中萃取出的沥青类物质进行了固体13C-CP/MAS NMR分析、元素分析、红外光谱分析(FT-IR)和光电子能谱(XPS)分析,得到煤液化沥青的芳香结构单元信息及相关结构参数信息。结果表明,煤液化沥青芳香桥碳与周碳之比为0.115,芳香碳原子的存在形式以苯结构为主;脂肪结构多以甲基和环状亚甲基形式存在;氧主要以羰基、酯基的形式存在;氮主要以吡咯的形式存在。利用结构参数和分析表征结果构建了煤液化沥青的大分子结构模型,并运用13C-NMR预测软件ACD/CNMR Predictor计算了煤精制沥青大分子结构模型的13C化学位移。根据计算结果对大分子结构模型进行了修正,获得了与实验谱图吻合较好的大分子结构模型。

Analysis and structural model of coal liquefaction asphaltene

The asphaltene extracted from coal liquefaction residue was studied by ¹³C-CP/MAS NMR, elemental analysis, FT-IR and XPS to reveal its aromatic unit structure and relative structural parameters. The results show that the ratio of bridged carbon to the surrounding carbon of asphaltene is 0.115. Benzene is the main form of aromatic carbon, and aliphatic structure exists mainly in the forms of alkanes and cyclic-methylene. Oxygen atoms present as carboxyl and ester group and nitrogen atom exits in the form of pyrrole. Based on structural parameters and analytic characterization, macromolecular structure model of refined asphaltene is constructed. ¹³C chemical shift of refined asphaltene is calculated by ACD/CNMR predictor. According to the calculation results, macromolecular structure model of refined asphaltene is corrected, and finally the calculated chemical shift diagram of model can tally well with the experimental result.