UNIFIED DESCRIPTION OF REAL FLUIDS AND THEIR MIXTURES BY GROUP-CONTRIBUTION LATTICE-HOLE THEORY

Based on a rigorous solution derived by the quasichemical approximatio n to the lattice-hole statistical-mechanical theory, a unified group c ontribution equation of state was formulated. The model was found to b e quantitatively applicable for the calculation and prediction of ther modynamic properties of real purr fluids and mixtures in general. The approach requires segment size and interaction energy parameter from f unctional group characteristics. The unique feature of the method is t hat a single set of temperature-dependent group parameters are used fo r both pure fluids and mixtures. The group parameters were determined and tabulated for various functional groups. Its applicability was dem onstrated for vapor pressures, binodals, and critical properties of pu re fluids including polymeric substances and phase-equilibrium propert ies of mixtures.