A Mini Review of the Potentials of Chlorella Species Microalge for the Production of Biocrude by Hydrothermal Liquefaction (HTL) Operation

The operation of hydrothermal liquefaction (HTL) of biomass is an enticing technique for the production of biocrude, which can serve as a viable alternative energy source to the growing universal energy demand and the pollution problem caused by fossil fuels. This article reviewed research publications that describe the elemental composition of Chlorella species biomass, biochemical analysis of the feedstock, the effects of the conditions of operating the Chlorella species biomass conversion, hydrothermal liquefaction mechanisms, separation technique, and the products of hydrothermal liquefaction operation. Nevertheless, the modification of the chemical and biochemical compositions of Chlorella specie biomass to yield higherquality biocrude was not researched. Also, other biocrude separation techniques, such as mechanical separation, were not researched after the hydrothermal liquefaction of the Chlorella specie biomass. This information can help in making decisions on the route where research should be directed, towards in-depth study, improvement of yield of the biocrude more than other products, and quality of the derived biocrude by the operation of hydrothermal liquefaction of Chlorella species biomass.