Low solvent, low temperature method for extracting biodiesel lipids from concentrated microalgal biomass.
An industrially relevant method for disrupting microalgal cells and preferentially extracting neutral lipids for large-scale biodiesel production was demonstrated on pastes (20-25% solids) of Nannochloropsis sp. The highly resistant Nannochloropsis sp. cells. were disrupted by incubation for 15 h at 37°C followed by high pressure homogenization at 1200 ± 100 bar. Lipid extraction was performed by twice contacting concentrated algal paste with minimal hexane (solvent:biomass ratios (w/w) of <2:1 and <1.3:1) in a stirred vessel at 35°C. Cell disruption prior to extraction increased lipid recovery 100-fold, with yields of 30-50% w/w obtained in the first hexane contact, and a further 6.5-20% in the second contact. The hexane preferentially extracted neutral lipids over glyco- and phospholipids, with up to 86% w/w of the neutral lipids recovered. The process was effective on wet concentrated paste, required minimal solvent and moderate temperature, and did not require difficult to recover polar solvents.
Department of Chemical & Biomolecular Engineering, The University of Melbourne, Parkville, Victoria 3000, Australia.
Ian L D
IL
Olmstead
Sandra E
SE
Kentish
Peter J
PJ
Scales
Gregory J O
GJ
Martin
D056804:Biofuels / Q000032:analysis*; D018533:Biomass; D001709:Biotechnology / Q000379:methods*; D003080:Cold Temperature; D008055:Lipids / Q000302:isolation & purification*; D058086:Microalgae / Q000166:cytology / Q000378:metabolism*; D012997:Solvents / Q000737:chemistry*
D056804:Biofuels; D008055:Lipids; D012997:Solvents
Biodiesel; Cell rupture; Microalgae; Nannochloropsis sp.; Solvent extraction