Lipid extraction from Chlorella vulgaris & Haematococcus pluvialis using the switchable solvent DMCHA for biofuel production

Switchable solvents (SS), also termed smart solvents, have the unique ability to change their polarity/hydrophilicity through a protonation reaction using CO₂. Recently, a novel method employing the use of SS for lipid extraction in microalgae has shown promising results. In this study the efficiency of the tertiary amine N, N-dimethyl cyclohexylamine (DMCHA) to extract lipids from the eukaryotic microalgae Chlorella vulgaris and Haematococcus pluvialis, was investigated using traditional hexane as a control under wet conditions. The results revealed that high lipid yields using DMCHA can be achieved in both species, however the extraction procedure is significantly more complex compared with hexane. This study found that lipid extraction of H. pluvialis, using DMCHA to be an efficient solvent, achieving a maximum lipid yield of 64.84%. Furthermore, DMCHA achieved a maximum lipid yield of 63.85% with C. vulgaris. The practicalities of DMCHA for lipid recovery are considerably more complex at larger volumes compared with hexane.