A review on bio-crude production from algal biomass using catalytic hydrothermal liquefaction process

The rising demand for cleaner energy among the nations has turned the focus from fossil fuel-based energy sources to renewables like biomass, solar, wind, etc. Biomass conversion to fuel has increased research in recent times due to its ease and availability throughout the year. Hydrothermal liquefaction is the process where biomass converts to a liquid product via complex reaction mechanisms. This review aims to summarize the hydrothermal liquefaction of algal biomass and the improvements in the bio-crude yield using heterogeneous and homogenous catalysts. Many references have been reviewed to provide the sources for the process and have been critically well structured. This review also provided information regarding the reaction pathway for algal biomass and the effects of process parameters like temperature, residence time, pH, etc. The focus of the review is on the effects of various catalysts based on their dosage whose results collected from various sources have been tabulated. The review briefly discusses the applications of products formed during hydrothermal liquefaction after post-processing.