ABSTRACT: Microalgae have received a great deal of attention as a platform for biofuel production due to their photosynthetic nature. However, the over emphasis on the production of lipids for biodiesel synthesis can limit the productivity of algae cultures and undervalues the potential applications for the significant quantities of protein and carbohydrate fractions present in this biomass. Currently, the commercial prospects for microalgae biofuels are primarily inhibited by their low cell densities and the high cost of current lipid extraction processes. Lipid extraction remains particularly challenging for microalgae due to the energy intensive dewatering and drying steps required prior to convention lipid extraction processes like organic solvent extraction.
Ionic liquids have been demonstrated to disrupt microalgae cell structure which is thought to facilitate the extraction of intracellular lipids. In this work, over 30 room temperature ionic liquids were screened for their ability to enhance lipid extraction and facilitate the recovery of the protein and carbohydrate fractions of microalgae biomass. The developed methodology resulted in a significantly shortened process which was performed at room temperature without comprising the lipid recovery. Oil quality and the effects of process conditions such as the water content of the algal biomass on the lipid yield was investigated. Recovery and reuse of the ionic liquid was quantified. Finally, recovery and ABE fermentation of the residual solids for the production of acetone butanol and ethanol will also be discussed.
Bio-sketch: Valerie recently completed her doctoral studies in biochemical engineering at the University of Western Ontario. She was the recipient of several awards including an NSERC Canadian Graduate Scholarship, an Ontario Graduate Scholarship, the E.D.J. Murray Biochemical Engineering Scholarship and currently holds an NSERC post-doctoral fellowship award for proposed research at MIT. Her doctoral work focused on the disruption and extraction of lipids from microalgae and oleaginous yeasts using ionic liquids. As part of her training she also received a BioFuelNet Canada HQP Exchange Award to work with some of the world’s leading ionic liquid chemists at Queen’s University in Northern Ireland. Prior to this, Valerie received a Master’s in chemical engineering from the University of Waterloo in 2012 where she worked on the development of a novel protein purification process using membrane chromatography.
Valerie’s current research interests include the production and purification of value added chemicals in microalgae, the design of ionic liquid catalysts for biomass processing, and the genetic engineering of microalgae for the production of terpenes used for the synthesis of aviation biofuels. She has a particular interest in developing integrated bioprocesses for the production of both commodity chemicals like biofuels concurrently with the production of high value chemicals in microalgae like carotenoids and omega fatty acids.