title: Energy requirements for wet solvent extraction of lipids from microalgal biomass.
abstract: Biofuel production from microalgae requires energy efficient processes for extracting and converting triacylglyceride lipids to fuel, compatible with coproduction of protein feeds and nutraceuticals. Wet solvent extraction involves mechanical cell rupture, lipid extraction via solvent contacting, physical phase separation, thermal solvent recovery, and transesterification. A detailed analysis of the effect of key process parameters on the parasitic energy demand of this process was performed. On a well-to-pump basis, between 16% and 320% of the resultant biodiesel energy was consumed depending solely on the process parameters. Highly positive energy balances can be achieved, but only if a correctly designed process is used. This requires processing concentrated biomass (ca 25%w/w) with a high triacylglyceride content (ca 30%w/w), and an efficient extraction process employing a non-polar solvent, low solvent-to-paste ratio, and efficient energy recovery. These requirements preclude many laboratory scale processes and polar co-solvents as viable options for large-scale biofuel production.
authors.affiliation: Algal Processing Group, Department of Chemical and Biomolecular Engineering, The University of Melbourne, Parkville, Victoria 3010, Australia. Electronic address: gjmartin@unimelb.edu.au.
authors.forename: Gregory J O
authors.initials: GJ
authors.lastname: Martin
mesh_terms: D056804:Biofuels; D018533:Biomass; D004735:Energy Transfer; D008055:Lipids / Q000302:isolation & purification*; D058086:Microalgae / Q000737:chemistry*; D012997:Solvents
chemical_list: D056804:Biofuels; D008055:Lipids; D012997:Solvents
keywords: Biofuel; Energy analysis; Lipids; Microalgae; Wet solvent extraction