title: Oil extraction from microalgae for biodiesel production.
abstract: This study examines the performance of supercritical carbon dioxide (SCCO(2)) 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 SCCO(2) 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.
authors.affiliation: Bio Engineering Laboratory, Department of Chemical Engineering, Monash University, Clayton, Victoria 3800, Australia. ronald.halim@eng.monash.edu.au
authors.forename: Ronald
authors.initials: R
authors.lastname: Halim
authors.forename: Brendan
authors.initials: B
authors.lastname: Gladman
authors.forename: Michael K
authors.initials: MK
authors.lastname: Danquah
authors.forename: Paul A
authors.initials: PA
authors.lastname: Webley
mesh_terms: D056804:Biofuels; D018533:Biomass; D002245:Carbon Dioxide / Q000737:chemistry; D000460:Chlorophyta / Q000737:chemistry*; D005227:Fatty Acids / Q000737:chemistry; D006586:Hexanes / Q000737:chemistry; D008055:Lipids / Q000737:chemistry; D009821:Oils / Q000737:chemistry*; D011312:Pressure; D012997:Solvents / Q000737:chemistry; D013696:Temperature
chemical_list: D056804:Biofuels; D005227:Fatty Acids; D006586:Hexanes; D008055:Lipids; D009821:Oils; D012997:Solvents; D002245:Carbon Dioxide; C026385:n-hexane