Surface-modified filter-based continuous recovery of solvent phase containing microalgal lipid

Abstract

Microalgal lipid is a promising feedstock for biofuels and value-added products. However, its production process including and lipid extraction still needs to be developed for the commercialization. Hexane-based solvent extraction with cell disruption is chosen and the amount of solvent is minimized considering the scalability of the extraction process. After solvent extraction, a highly concentrated emulsified mixture of lipid-in-hexane, aqueous medium and delipidated Schizochytrium sp. ABC101 debris is produced and usually phase-separated via centrifugation to separate solvent phase. Because centrifugation is usually operated in a batch manner with high operational and investment cost, a continuous and cost-effective solvent phase recovery is required. Therefore, a new total integrated separation system using a hydrophobic/oleophilic surface-modified sponge via initiated chemical vapor deposition (iCVD) process is devised. By simply immersing the modified sponge into the emulsified mixture, the solvent phase is absorbed spontaneously into the sponge and recovered continuously by pumping out. Our system can be applied to various extraction methods and shows high separation yield of 95% and flux of maximum 2640 $Lm^-2h^-1$. Moreover, the separation performance is maintained during a long operation. The filter-based separation method developed in this study will be a useful platform for microalgae lipid production.