1. MINES ParisTech, CEP/TEP - Centre Energétique et Procédés, 35 Rue Saint Honoré, 77305 Fontainebleau Cedex, France, Thermodynamics Research Unit, School of Chemical Engineering, University of KwaZulu-Natal, Howard College Campus, Durban, South Africa, and Rhodia, Centre de Recherches et Technologies de Lyon, 85 Avenue des Frères Perret, BP62, 69192 Saint-Fons Cedex, France