Extraction of carotenoids and lipids from algae by supercritical CO₂ and subcritical dimethyl ether

Algae contain lipids and functional compounds such as carotenoids. Especially, microalgae are recently focused as a source of biofuel. To extract these components, organic solvent or supercritical carbon dioxide have been used. We have been developing wet extraction process using liquefied (subcritical) dimethyl ether (DME) as solvent at around 0.59 MPa. The extraction process usually requires energy consuming drying and grinding process as in the case of supercritical CO₂. We have applied liquefied DME for the extraction of lipids and functional compounds from various kinds of algae. Since the liquefied DME extraction process can eliminate the process for drying, cell disruption, and solvent evaporation, it can realize simpler and low energy consumption system. In this paper, our studies on the extraction from algae by using supercritical CO₂ or subcritical DME are reviewed.