Phase-Equilibrium Measurements and Thermodynamic Modeling of CO₂ + Geraniol, CO₂ + Geraniol + Acetic Acid, and CO₂ + Geraniol + Ethyl Acetate

Abstract

This work reports the phase-equilibrium measurements and thermodynamic modeling for the binary system CO2 + geraniol, and two ternary systems comprising these components and ethyl acetate or acetic acid, which are related to geraniol (trans)­esterification using supercritical CO2 as a solvent. Measurements at each composition were carried out in a high-pressure variable-volume view cell at temperatures ranging from 303.2 to 343.2 K. The CO2 molar fraction ranged from 0.4120 to 0.9325 in the CO2 + geraniol system, from 0.5526 to 0.8000 in the CO2 + geraniol + acetic acid system, and from 0.6011 to 0.8993 in the CO2 + geraniol + ethyl acetate system. Under these conditions, vapor–liquid (VL), liquid–liquid (LL), and vapor–liquid–liquid (VLL) phase transitions were detected. The experimental data were modeled with the Peng–Robinson cubic equation of state with the van der Waals (vdW2) quadratic mixing rule.