Hydrothermal liquefaction of Chlorella pyrenoidosa and Spirulina platensis: NMR analysis of bio-crude oil composition and molecular dynamics

Abstract

The increasing global demand for sustainable energy sources has directed significant research toward biofuels derived from renewable biomass. This thesis investigates the potential of Phytoplankton as a biofuel feedstock, focusing on its conversion into energy-dense biocrude via hydrothermal liquefaction (HTL). The study explores the influence of varying temperatures and pressures on the yield and chemical changes of the resulting products. Nuclear Magnetic Resonance (NMR) spectroscopy was employed to investigate the transformation of different organic functional groups—such as aliphatics, aromatics, and oxygen- or nitrogen-containing compounds—within the algal biomass during the HTL process. By tracking these changes, NMR enabled a deeper understanding of the chemical pathways involved, allowing for optimization of HTL conditions to improve biocrude yield while minimizing undesirable oxygenated by-products. The findings contribute to the broader understanding of biomass conversion chemistry and highlight the value of advanced NMR techniques in monitoring and guiding the production of cleaner, more efficient algal biofuels.