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.