Energy efficient electric field-assisted green extraction of yeast oil for advanced biodiesel production

Single Cell Oil (SCO) is a new generation oil for industrial applications aiming at replacing edible oils as feedstock for biofuels and chemicals. One of the main bottlenecks for the scale-up of SCO production is related to the cost and environmental impact of traditional methods for extracting SCO from yeast cells. This study developed a laboratory-scale apparatus for the pretreatment of Lipomyces starkeyi cells to improve lipids extraction. The process adopts a low power and low voltage electric field treatment device for permeabilising the cell's membrane before the lipids recovery by solvent extraction using the bio-based 2-methytetrahydrofuran. Under the optimised process conditions (10 V/cm, 2 min), the recovered SCO cell content (30.0 wt%) was equal to that achieved with the standard acid-catalysed protocol. The extracted SCO was characterised by infrared spectroscopy and used to produce advanced biodiesel with a yield of 84 wt%. The FAMEs profile and the physico-chemical properties of this new generation biofuel were determined and compared to standard biodiesel (EN 14214 and ASTM D6751). With a particular focus on the production of next-generation biodiesel, this novel process has significant potential to replace conventional cell treatments, offering improved efficiency and sustainability.