## 4 Conclusions  
The two MLCTs derived from the pyrolysis of low-grade bituminous coal, which had a high H/C ratio, high-oxygen and nitrogen, low-sulfur, low density and low viscosity, show obvious characteristics of medium-low temperature coal tar. The fractions below 170 \({}^{\circ}\)C, mainly consisting of benzene, toluene, and xylene, are suitable feedstock for chemical products rich in BTX aromatics. The 170-230 \({}^{\circ}\)C distillate fractions of MLCT have high oxygen content and are rich in phenols, which are the main raw chemical materials in the chemical industry and should be extracted from coal tar before hydrogenation. The \(>\)360 \({}^{\circ}\)C heavy distillate fraction, which belongs to coal tar pitch, accounted for about half of  
\begin{table}
\begin{tabular}{l c c c c c c c c c c} \hline \hline
**Distilling** & **H\({}_{\rm A}\)(\(\thickapprox\) 10.0–6.0)** & **H\({}_{\rm A}\)(\(\thickapprox\) 2.0–24.0)** & **H\({}_{\rm B}\)(\(\thickapprox\) 1.0–21.0)** & **H\({}_{\rm A}\)(\(\thickapprox\) 0.5–21.0)** & **H\({}_{\rm A}\)(\(\thickapprox\) 14–20)** \\ \cline{2-10}
**Range\({}^{\circ}\)C** & **MLCT-Z** & **MLCT-S** & **MLCT-Z** & **MLCT-S** & **MLCT-Z** & **MLCT-S** & **MLCT-Z** & **MLCT-S** \\ \hline full range & 17.47 & 13.69 & 18.43 & 17.00 & 41.84 & 46.25 & 13.63 & 15.56 & 8.64 & 7.49 \\ IBP-170 & 16.03 & 20.28 & 17.47 & 16.84 & 34.29 & 29.82 & 21.47 & 18.46 & 10.74 & 14.60 \\
170–190 & 37.84 & 38.17 & 21.62 & 20.61 & 22.39 & 22.90 & 11.58 & 11.45 & 6.56 & 6.87 \\
190–210 & 34.25 & 35.34 & 31.16 & 32.51 & 19.86 & 18.37 & 8.90 & 8.48 & 5.82 & 5.30 \\
210–230 & 26.95 & 28.99 & 36.39 & 36.81 & 22.64 & 20.58 & 8.89 & 8.70 & 5.12 & 4.93 \\
230–250 & 22.22 & 23.81 & 31.56 & 31.67 & 26.00 & 24.76 & 12.22 & 11.43 & 8.00 & 8.33 \\
250–270 & 15.80 & 22.62 & 26.07 & 31.11 & 24.64 & 26.48 & 26.22 & 11.13 & 7.27 & 8.48 \\
270–300 & 21.84 & 21.79 & 24.60 & 29.41 & 33.33 & 29.19 & 13.56 & 11.33 & 6.67 & 8.28 \\
300–320 & 21.93 & 24.57 & 24.56 & 25.80 & 33.33 & 30.47 & 13.60 & 12.29 & 6.58 & 6.88 \\
320–340 & 24.00 & 23.36 & 21.36 & 23.13 & 34.85 & 34.35 & 14.77 & 13.32 & 5.02 & 5.84 \\
340–360 & 15.36 & 45.66 & 55.31 & 19.18 & 11.54 & 14.16 & 9.31 & 5.94 & 8.48 & 15.07 \\ \(>\)360 & 42.52 & 22.99 & 20.09 & 20.69 & 17.29 & 39.77 & 7.01 & 9.89 & 13.08 & 6.67 \\ \hline \hline \end{tabular}
\end{table}
Table 3: Hydrogen types in distillate from MLCT-Z and MLCT-S.  
the total mass, is exceedingly difficult to hydrogenate, and has a low economic value. Although the macroscopic properties of the MLCT-Z and MLCT-S are quite similar, the molecular composition, group composition, and hydrogen distribution in each MLCT and their narrow distillate fractions are still different.  
Data curation, N.Z. and C.W.; formal analysis, N.Z. and N.S.; methodology, N.Z. and F.W.; writing--original draft, N.Z.; writing--review & editing, D.L. and H.D.  
This research was funded by the National Key Research and Development Program (2018 YFC1801901), Fundamental Research Funds for the Central Universities (18 CX05024A, 18 CX06062A, 17 CX05016), as well as the China Postdoctoral Science Foundation (2019T120571, 2018M632623).  
The authors declare no conflict of interest.