Chapter 5 Multimethod and multiproduct microalgae biorefineries: industrial scale feasibility: eutectic solvents as a novel extraction system for microalgae biorefinery

Eutectic solvents (ES), including “deep eutectic solvents,” hold great potential as an extraction system for microalgae. Besides being virtually inflammable, ES can be readily prepared from bioderived and biodegradable compounds. Several hydrophilic/ hydrophobic ES can form pores or cracks in the cell wall of various microalgae, which enhanced the lipid extraction yield even without the cell disruption step. The tailorable properties of ES may also open possibilities for process integration. For instance, hydrophobic ES can be used to pretreat the biomass and extract the lipids simultaneously. However, the low volatility of ES complicates the process due to the challenging separation of lipids from the solvent. Therefore, this we aimed to develop suitable ES for lipid extraction from microalgae and further evaluate the feasibility of microalgae biorefinery. In this chapter, the major breakthroughs and challenges are summarized. Moreover, the future outlook on the ES application for microalgae biorefinery is discussed.