Performance of continuous countercurrent extractor on the fractionation of Citrus bergamia essential oil using ethanol/water mixtures as solvents

Bergamot model mixture and crude bergamot essential oil (CBEO) were fractionated in a perforated rotating disc contactor (PRDC) using as solvents ethanol with 30% (Et30) and 40% (Et40) water, in mass. The apparatus performance was evaluated by experimental extraction indices, essential oil (EO) folding and estimative of mass transfer coefficients. The effects of the solvent to feed mass flow ratio (S/F), disc rotation speed (DRS), feed composition, and water content in the solvent over the process performance were thus appraised. Furthermore, the fractionation of model mixtures was simulated by Aspen Plus software. It was experimentally verified that higher S/F improved the extraction indices and mass transfer, whereas solvent Et40 and higher DRS also contributed for that results. Solvent Et40 extracted lower amount of components from the EO, but the Folds were similar to the ones achieved using solvent Et30. The simulation followed the same tendency. For the model mixture, a 1.54-fold EO was obtained, while for the CBEO a 1.4-fold EO was reached. Overall, solvent Et40, S/F close to 2, and low DRS exhibited the best results for the fractionation of CBEO in PRDC. (C) 2018 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved. (AU)