Table of Contents
Journal of Thermodynamics
Volume 2011, Article ID 730960, 9 pages
http://dx.doi.org/10.1155/2011/730960
Research Article

Supercritical Phase Equilibria Modeling of Glyceride Mixtures and Carbon Dioxide Using the Group Contribution EoS

Department of Production and Characterization of Novel Foods, Instituto de Investigación en Ciencias de la Alimentación CIAL (CSIC-UAM), C/Nicolás Cabrera, 9. Campus de Cantoblanco, 28049 Madrid, Spain

Received 19 May 2011; Revised 27 July 2011; Accepted 29 July 2011

Academic Editor: Roumiana P. Stateva

Copyright © 2011 Tiziana Fornari et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

The Group Contribution Equation of State (GC-EoS) was extended to represent high-pressure phase equilibria behavior of mixtures containing mono-, di-, triglycerides, and carbon dioxide (CO2). For this purpose, the alcohol-ester and the alcohol-triglyceride binary group interaction parameters were regressed in this work, using experimental phase equilibria data from the literature. The capability of the parameters obtained was assessed by applying the GC-EoS model to simulate the supercritical CO2 fractionation of a complex glyceride mixture, which was produced by the ethanolysis of sunflower oil. Experimental data was obtained in a countercurrent packed extraction column at pressures ranging from 16 to 25 MPa and temperatures from 313 to 368 K. The GC-EoS model was applied in a completely predictive manner to simulate the phase equilibria behavior of the multistage separation process. The chemical analysis of the glyceride mixture allowed a significant simplification of its complex composition and thus, a simple and satisfactory simulation of the supercritical extraction process was achieved.