A NEW NONRANDOM LATTICE FLUID MODEL AND ITS SIMPLIFICATION BY 2-LIQUID THEORY FOR PHASE-EQUILIBRIA OF COMPLEX-MIXTURES

A new riogorous equation of state (EOS) and its simplified version hav e been proposed by the present authors based on the full Guggenheim co mbinatorics of the nonrandom lattice hole theory. The simplified EOS, with the introduction of the concept of local composition, becomes sim ilar to the density-dependent UNIQUAC model. However, in the present a pproach we have a volumetric EOS instead of the excess Gibbs function. Both EOSs were tested for their applicability in correlating the phas e equilibria behavior of pure components and complex mixtures. Compari son of both models with experiment includes such systems as nonpolar/n onpolar, nonpolar/polar, and polar/polar hydrocarbons, supercritical s ystems, and polymer solutions. With two parameters for each pure compo nent and one binary interaction energy parameter, results obtained to date demonstrate that both formulations are quantitatively applicable to complex systems oer a wide range of temperatures, pressures, and co ncentrations.