This study examines the performance of supercritical carbon dioxide (SCCO2) extraction and hexane
extraction of lipids from marine Chlorococcum sp. for lab-scale biodiesel production. Even though the
strain of Chlorococcum sp. used in this study had a low maximum lipid yield (7.1 wt% to dry biomass),
the extracted lipid displayed a suitable fatty acid profile for biodiesel [C18:1 (63 wt%), C16:0 (19
wt%), C18:2 (4 wt%), C16:1 (4 wt%), and C18:0 (3 wt%)]. For SCCO2 extraction, decreasing temperature
and increasing pressure resulted in increased lipid yields. The mass transfer coefficient (k) for lipid
extraction under supercritical conditions was found to increase with fluid dielectric constant as well as
fluid density. For hexane extraction, continuous operation with a Soxhlet apparatus and inclusion of isopropanol
as a co-solvent enhanced lipid yields. Hexane extraction from either dried microalgal powder or
wet microalgal paste obtained comparable lipid yields.