Analysis of distillate product in the direct coal liquefaction of a Chinese bituminous coal

To understand the reaction mechanism of coal liquefaction process and further improve the direct coal liquefaction (DCL) technology, a certain kind of DCL oil, which was prepared from a Chinese bituminous Yulin coal, was first separated into different fractions using improved silica-gel column chromatography (SGCC) coupled with the UV-absorbance detector, and then identified by gas chromatography-mass spectrometer (GC-MS), the comprehensive two-dimensional gas chromatography coupled with time-of-flight mass spectrometer (GC x GC-TOFMS), H-1 NMR and FTIR. Around 95% of DCL oil was successfully separated into seven fractions by four mobile phases and analysed. It was found that DCL oil consists of 9.06% of alkanes, 36.32% of hydroaromatics, 17.85% of aromatics, 15.39% of oxygen-containing compounds, 16.21% of nitrogen-containing compounds and 2.33% of polyheteroatomic compounds, respectively.