THERMODYNAMICS OF COAL-DERIVED FLUIDS .1. PHASE-EQUILIBRIA IN MULTIRING AROMATIC-COMPOUNDS

Coal-derived liquids consist mainly of multi-ring compounds with finit e amounts of organic nitrogen, sulfur and oxygen. A thermodynamic mode l for phase equilibria of systems containing these compounds has been developed. The model uses the characterization of complex mixtures in terms of functional groups that is available in the literature. This c haracterization allows the functional group composition of mixtures to be computed directly from the results of chemical analysis. The UNIFA C activity coefficient model is used for the liquid phase, and the Hay den-O'Connell virial equation for the vapour phase. All the properties of compounds required in the correlations are obtained from group con tributions of the functional groups that constitute the compounds. Eva luation of this model with VLE data in the literature shows good agree ment.