Co-Solvent Assisted Hydrothermal Liquefaction of Algal Biomass and Biocrude Upgrading

This study reports the hydrothermal liquefaction (HTL) of microalgae Spirulina platenesis in presence alcohol or formic acid co-solvents. HTL runs are performed a 1.8-L batch reactor at 300 °C using an (methanol and ethanol) co-solvent. Consequently, hydrodeoxygenation (HDO) resultant algal biocrude is 350 for 2 h under high hydrogen pressure (~725 psi) Ru/C catalyst. The results compared with control run water only. show that addition co-solvents leads to 30–63% increased yield over run. Formic 59.0% biocrude, highest amongst all tested. Resultant biocrudes from acid-assisted ethanol-assisted have 21.6% 3.8–11.0% higher energy content, respectively, than However, methanol-assisted 4.2–9.0% lower density. Viscosity methanol- but less viscous product. In addition, HDO 40.6% upgraded oil, which characterized by net content O/C N/C ratios when initial biocrude.