Applications of supercritical CO₂ extraction to microalgae and plants

A flow apparatus was constructed to carry out studies of supercritical fluid extraction in the temperature range 298·15–353·15 K and pressures up to 40 MPa. To test the apparatus, studies on the solubility of naphthalene in CO 2 at 308·15, 313·15 and 318·15 K and pressures up to 35 MPa were carried out. These experimental data were correlated through the Peng–Robinson equation of state. Samples of the microalgae Botryococcus braunii and Chlorella vulgaris which produce diolefines C 25 –C 31 and carotenoids, respectively, were submitted to supercritical CO 2 . The extraction yields for these compounds were studied and compared with those obtained using organic solvents. Supercritical CO 2 was also used to produce extracts from rosemary leaves ( Rosmarinus officinalis L.), which were compared with those obtained by hexane extraction.