Study of a predictive model based on the group-contribution equation of state, applied to the solubility of carotenoids in supercritical CO2

FACUNDO MATTEA; ÁNGEL MARTÍN; MARÍA JOSÉ COCERO

Iguazu Falls

Congreso; I Iberoamerican Conference on Supercritical Fluids; 2007

Plapiqui (Argentina)

The aim of this work is to study a model of the solubility of different carotenoids in supercritical CO2. This model is based in a Group-Contribution Equation of State (GC- EoS), which can be used to predict the phase equilibrium data in systems in which experimental information is scarce. The model is based on the method proposed by Skjold- Jorgensen where all the necessary quantities to calculate the phase equilibrium of a given system can be derived from information of the molecular structure of the substances present in the system. Also, the critical diameter of the molecules is required in the model. This parameter can be obtained from the critical pressure and temperature of the substances; however if these critical constants are unknown a GC method can be used to predict them. In this work two different GC methods: Constantinou & Gani’s and Joback’s methods where used to predict the unknown critical constants. The accuracy of the model is studied by comparing the predictions of the GC-EoS with experimental data of the solubility of β- carotene in SC-CO2. Because the solubility of carotenoids in supercritical CO2 is very low, difficult and expensive to measure the application of the model as a predictive tool is of great importance.