Advancement of biocrude valorization to fuels: A comprehensive review

Abstract

In response to address the climate crisis, there has been a growing focus on substituting conventional refinery-derived products with those derived from biorefineries. The utilization of biocrude as primary materials or intermediates for the synthesis of fuels, which are integral to the existing chemical and petrochemical industries, is a key step in this transition. This review provides a comprehensive overview of the production of gasoline, kerosene, biodiesel, and heavy fuel oil from biocrude derived from terrestrial and algal biomass. Pyrolysis is a preferable option to make biocrude from dry biomass, while hydrothermal liquefaction is more preferable to treat wet biomass than pyrolysis for biocrude production. The transformation of biocrude into biofuels can be achieved through processes such as catalytic cracking, hydroprocessing, and transesterification. Catalytic cracking is used to produce gasoline- and kerosene-range chemicals, and hydrotreatment is mainly employed to produce diesel-range chemicals. Hydroprocessing is commonly required to upgrade the biocrude-derived fuel quality. Biocrude can be blended with heavy fuel oil to inhibit the increase in biocrude's viscosity. To further improve the effectiveness of biocrude-based fuel production, future research should focus on improving the fuel quality, increasing the fuel yield, reducing energy requirements of overall process, and securing biomass availability.