Effect of Operating Conditions on the Conversion of Defatted Microalgae Biomass to Bio-Oil Through Hydrothermal Liquefaction

Muhammad Khairul Hilmi Mohd Zaki; Shafirah Samsuri

Authors

Muhammad Khairul Hilmi Mohd Zaki Department of Chemical Engineering, Universiti Teknologi PETRONAS, Perak, Malaysia Author
Shafirah Samsuri Centre of Biofuel and Biochemical Research (CBBR), Universiti Teknologi PETRONAS, Perak, Malaysia Author

Keywords:

Biomass, sustainable biofuel, hydrothermal liquefaction, reaction temperature, reaction time, lipid-extracted microalgae

Abstract

The growing demand for sustainable energy has increased interest in bio-oil production from microalgae via hydrothermal liquefaction (HTL). However, limited research exists on utilising defatted microalgae biomass, the residue after lipid extraction. Therefore, this study investigates the effects of different operating conditions on the conversion of defatted Chlorella sp. microalgae biomass into bio-oil through HTL. Defatted biomass undergoes HTL at varying temperatures (210–270oC) and reaction times (30–90 min). Gas chromatography-mass spectrometry (GC-MS) analysis shows that reaction conditions influence bio-oil composition, which consistently contains aliphatic acids, amides, amines, pyrazine, pyridine, and phenolic compounds. Aliphatic acids, crucial for biofuel applications, are most abundant at 250–260oC and 45 min, indicating optimal conditions. Future work will explore broader parameters, including pressure and catalysts, to enhance bio-oil properties.