Research progress in the preparation of high-quality liquid fuels and chemicals by catalytic pyrolysis of biomass: A review

Considering the pressures of energy and the environment, using renewable resource—biomass to obtain hydrocarbon fuels and high-value chemicals has important application value and broad market prospects. However, due to the complex pyrolysis process of biomass, low calorific value, high oxygen content and strong acidity of bio-oil, the application of bio-oil as liquid fuel and chemicals are restricted. It is urgent to improve the quality of bio-oil. In this paper, the effects of biomass raw materials, pretreatment methods, co-pyrolysis of hydrogen donors and pyrolysis reaction conditions on the preparation of bio-oil by fast pyrolysis of biomass are described in detail. The article further discusses the research progress of biomass pyrolysis to prepare liquid fuel and high-value chemicals, including direct catalytic pyrolysis of biomass to prepare high-quality bio-oil, fast pyrolysis to prepare bio-oil and then catalytic upgrading, pyrolysis to prepare ketone and furan platform compounds, and then aldol condensation and catalytic hydrogenation. The main achievements and problems of three different synthesis techniques are reviewed objectively. Finally, the catalytic characteristics of catalysts are introduced by classification, and the specific applications and reaction mechanisms of different catalysts in catalytic pyrolysis, catalytic cracking and catalytic hydrogenation are systematically summarized, which provides a new direction for the research of lignocellulose biomass energy utilization.