Bio-oil Production by Hydrothermal Liquefaction of Wet Biomass of Microalgae in a Plant with Heat Recovery

In this paper, a description of a new energy-efficient plant designed for the hydrothermal liquefaction (HTL) of microalgae, as well as the results of a study of HTL of A. platensis in the plant at 280 °C is presented. Bio-oil in this work was obtained without the use of any organic solvents. The yield of bio-oil was 29.5%. The calorific value of obtained bio-oil was 34.2 MJ/kg. The yield of the gasoline fraction of bio-oil was 26%. The paper presents computational calculations showing that HTL has a high thermodynamic efficiency due to heat recovery. Experimental exploitation of the plant showed that up to 35% of the heat energy spent on HTL is recovered by proposed heat recuperation.