Hydro-liquefaction of asphaltene from a lignite for potential jet fuel

Hydro-liquefaction of an asphaltene from thermal dissolution of Xinlinguole lignite (XLAS) was carried out, and the effects of catalyst, temperature and reaction time on oil yield and cyclanes content in oil for the potential jet fuel were probed in this study. Comparing the hydrogenation activities of three catalysts i.e. Cu-Ni/γ-Al₂O₃, Ni/ZSM-5 and Ni-Mo-S/γ-Al₂O₃, it was found that Ni-Mo-S/γ-Al₂O₃ was the most beneficial for jet fuel production from coal liquefied oil due to it contained a continuous distribution of weaker to stronger acidic sites. It gave the highest oil yield of 68.8%, and cyclanes content of 20.5% in the oil, which displayed the highest hydrogenation activity for arenes saturated hydrogenating among the three catalysts used in the hydro-liquefactions of XLAS at 360 °C for 90 min. For Cu-Ni/γ-Al₂O₃, it only contained weak acidic sites therefore it gave the lowest saturated hydrogenating activity. With rising of temperature, oil yield increased, but cyclanes content in oil decreased in the hydro-liquefactions of XLAS under Ni-Mo-S/γ-Al₂O₃ catalyst. The highest content of cyclanes (29.3%) in oil was obtained at 280 °C for 90 min. Reaction time remarkably affected cyclanes content in oil. With the reaction time prolonging from 30 to 60 min, oil yield and cyclanes content in oil increased. Further prolonging reaction time to 90 min, oil yield hardly increased, but cyclanes content in oil decreased from 23.6% to 20.5% at 360 °C with Ni-Mo-S/γ-Al₂O₃ catalyst. Some oxygen-containing compounds (OCs) may convert into cyclanes by hydro-deoxygenation (HDO) with increasing of reaction time. © 2019 Elsevier Ltd