Conversion of pyrolytic lignin to aromatic hydrocarbons by hydrocracking over pristine MoO3 catalyst

Abstract

Pyrolytic lignin obtained by separation of the fast pyrolysis bio-oil of biomass is problematic for use as a fuel and chemical. A catalytic cracking process for pyrolytic lignin was therefore explored using pristine catalysts (MoO3, HZSM-5, and α-Al2O3). The results demonstrated that pyrolytic lignin can be converted into aromatic hydrocarbons and phenols in a one-pot process. Among the three catalysts, MoO3 was more efficient for aromatic hydrocarbons and phenols, with yields of up to 9.2 and 7.9 wt%, respectively, under the conditions of 340 °C and an H2 atmosphere. Catalyst dosage, reaction temperature, and H2 pressure were investigated in detail, and it was found that the aromatic hydrocarbon yield was highly catalyst dosage dependent. The regeneration of used catalyst was also explored, and the catalytic activity of regenerated MoO3 catalyst was recovered by calcination in the presence of O2. This work provides a potential alternative for the production of aromatic hydrocarbons and phenols from pyrolytic lignin.