Supercritical CO2-mediated countercurrent separation of essential oil and seed oil

Abstract Supercritical carbon dioxide (SCCO 2 ) separation of essential oil and seed oil in citrus processing residues was investigated taking d -limonene and canola oil as model compounds, respectively, in a continuous countercurrent column. The effect of temperature and pressure on the recovery of d -limonene from top of the extraction column was investigated. Temperature gradient along the column was also applied to achieve more effective separation. At isobaric condition (10 MPa), the highest enrichment of d -limonene in the extract could be obtained at 60 °C. However, the highest recovery of the extract was found at 30 °C. Evaluation of the separation performance of this proposed process was carried out by calculation of mass transfer correlation coefficient, theoretical number of separation stages and solubility of the components in SCCO 2 .