Hydrothermal liquefaction of biomass for jet fuel precursors: A review

Climate change is an important issue facing the world today and carbon reduction has become the focus of attention for all countries. Alternative bio-fuels are an important means to achieve carbon emission reduction. The production of jet fuel precursors from biomass by hydrothermal liquefaction (HTL) has received a lot of attention due to its mild conditions and environmental friendliness. Lignocellulosic biomass and algal biomass are considered as the second and the third generation biomasses as promising raw materials for alternative fuel preparation. Among them, lignocellulosic biomass has been extensively studied due to its wide range of sources and can be divided into one-step HTL and stepwise HTL according to the process method. Algal biomass has been extensively studied experimentally due to its short growth cycle and the fact that it can sequester large amounts of carbon without taking up arable land. In this paper, the feedstock composition of different biomasses is reviewed for the HTL of biomass. A detailed review of the process characteristics, reaction pathways and influencing factors for the HTL production of jet fuel precursors from lignocellulosic biomass and algal biomass is also presented. Theoretical references are provided for further process optimization and bio-crude quality upgrading.