Phase equilibria of palm oil, palm kernel oil, and oleic acid + supercritical carbon dioxide and modeling using Peng–Robinson EOS

Vapor–liquid equilibria of the binary supercritical carbon dioxide (scCO2) + oleic acid, scCO2 + palm oil, and scCO2 + palm kernel oil were measured at a wide range of temperatures from 333.2 to 373.2 K and pressures from 8.5 to 35 MPa in a circulation-type phase equilibrium apparatus. The samples from liquid and vapor phases were analyzed using UV–vis spectrometer and a liquid hold-up equipment. The phase equilibrium data were correlated with Peng–Robinson Equation of State (PR-EOS) using Wong–Sandler mixing rule and optimum values of binary interaction parameters were determined. The relative deviation between experimental data and predicted data was in the range of 6.9–8.7%, suggesting that the PR-EOS with Wong–Sandler mixing rule is capable of predicting the vapor–liquid equilibria of oleic acid + scCO2, palm oil + scCO2, and palm kernel oil + scCO2.