Extension of the AEOS model to systems containing any number of associating and inert components

Abstract

The AEOS (association + equation of state) model is extended to mixtures containing any number of associating and inert components. The model is based on a continuous linear association scheme for molecules forming self-associates and cross-associates. The pure component parameters are determined from vapor pressure and liquid density data. The equation represents vapor—liquid equilibria over a wide pressure and temperature range with accuracy similar to that of experimental data. Results of calculating low-pressure vapor—liquid equilibria compare favorably with those obtained from activity coefficient methods. The well-established temperature dependence of the adjustable parameter makes possible a safe extrapolation beyond the experimental temperature range. Ternary vapor—liquid equilibria are accurately predicted from binary data. For mixtures containing chemically similar compounds vapor—liquid equilibria are fairly well predicted without any adjustable parameters.