Recovery of valuable compounds from palm-pressed fiber by using supercritical CO₂ assisted by ethanol: modeling and optimization

The objective of this study is to examine the effect of operating conditions in terms of percentage of oil yield, total tocopherols compounds (TTC), and total carotene compounds (TCC). The second objective is to obtain extraction rate by using Esquivel model and to correlate the solubility of solute in SC-CO₂ by using semi-empirical models (Chrastil and Del Valle Aguilera). The maximum oil yield 18.49%, TTC 2020.09 mg/kg, and TCC 2076.96 mg/kg at 29.96 MPa, 50°C and 7.5% ratio of co-solvent. Average absolute relative deviation (AARD %) of Chrastil and Del Valle Aguilera were 2.15% and 1.99%, respectively. The average calculated mass transfer of TTC, TCC, and oil yield by the Esquivel model were 0.60 mg/s, 0.52 mg/s, and 1.61 mg/s.