Modeling the Phase Behavior of Essential Oils in Supercritical CO2 for the Design of a Countercurrent Separation Column

Abstract

This work describes a generalized procedure for high pressure equilibrium calculations for terpene oils. A simple semiempirical model allows the prediction of the solubilities of essential oils at high pressure on the basis of the physicochemical properties of their compounds (molecular weight, boiling temperature, density, and solubility parameter). This easy model can be useful for the determination of the fractionation and for the preliminary scale-up and economic evaluation. The theoretical basis considers any essential oil composed of two types of components: oxygenated and nonoxygenated. Vapor–liquid equilibrium data of binary systems (terpenoids/CO2) are used to correlate the semiempirical model proposed. Validity of the prediction is checked by comparison with literature data concerning ternary systems (limonene + linalool + CO2) and real mixtures (lemon and orange oils + CO2). Finally, the simulation and optimization of a countercurrent column for the fractionation of terpenes from lemon oil are ...