Supercritical CO2 extraction of nutmeg oil: Experiments and modeling

Nutmeg oil was extracted from nutmeg seed at pressures of 15–20 MPa and temperatures of 313–323 K with supercritical CO2. The effects of separation parameters such as temperature, pressure, CO2 flow rate and particle size on the extraction rate of nutmeg oil were observed. Broken and intact cells (BIC) model combined with discontinuous phase equilibrium between fluid phase and solid phase, and shrinking core model were selected to describe the extraction process. For BIC model, the initial fraction solute in broken cell to total solute in the ground particle f, dimensionless transition concentration Xc and partition coefficient K were used as fitting parameters. For shrinking core model, two effective diffusivities De were used as fitting parameters. The best fitting of De1 was from 4.33 × 10−9 to 7.69 × 10−8 m2/s and De2 was from 1.90 × 10−9 to 3.20 × 10−8 m2/s. From comparison of experimental data and models calculation, the shrinking core model could describe the experimental data well for all extraction conditions, while the BIC model could only describe the data at lower extraction yields well.