Supercritical carbon dioxide separation of bergamot essential oil by a countercurrent process

摘要

The efficiency of separation of bergamot essential oil, performed by a countercurrent column filled with Raschig rings and using supercritical carbon dioxide as partition solvent, is affected by various parameters. In the experiments explained in this work, the direct effect of CO_2 density was shownand the ratio between the amount of oil loaded to on the column and the amount of CO_2 used were discussed. The conitions that produced extacts with a similar volatile fraction composition of starting materil and with a high yield (more than 80% of recovery) were those with a low feed:solvent ratio; the lowest bergapene content was obtained at low CO_2 density or at high feed:solvent ratio. A good results was observed at a CO_2 density of 206 g/dm~3 (8 MPa pressure and a temperature gradient of 46-50-54 deg C) and a feed:solvent ratio of 9.4-9.6; in this separation, a yield of 74-77% and a bergaptene content owner than 0.01% was measured.