A REFINED LATTICE-HOLE THEORY WITH GROUP-CONTRIBUTION FOR UNIFIED DESCRIPTION OF SINGLECOMPONENT AND MULTICOMPONENT REAL FLUIDS

A lattice statistical-mechanical theory combined with a new group cont ribution was formulated for the unified description of thermodynamic p roperties of fluids. The formulation provides a simple procedure for p redicting thermodynamic properties in terms of only two functional gro up parameters reflecting size of groups and energetic interaction betw een groups. The approach quantitatively describes pVT behaviors, phase transition, and phase equilibrium of various classes of single-and mu lti-component fluids. With a single set of temperature-dependent group parameters, predictions have been made even for the properties that a re not readily accessible experimentally such as the vapor pressures o f high carbon number pure alkanes and vapor-liquid equilibria of binar y mixtures of any combination of such alkanes. Also, with an emphasis on engineering practices, the reliable predictability of the present m odel was demonstrated for vapor-liquid equilibria of hydrocarbons, sup ercritical fluids and polymer solutions. (C) 1997 Elsevier Science B.V .