Excess Gibbs Free Energy Model for Calculating the Viscosity of Binary Liquid Mixtures

Abstract

In this article we present a model for correlating dynamic and kinematic viscosities of liquid mixtures, which is based on Eyring's absolute rate theory for liquid viscosity and the UNIQUAC equation. The proposed model involves the concept of ideal viscosity and uses the UNIQUAC equation to represent the deviation from ideal behavior. The expression adopted to describe the ideal term viscosity has been chosen after a thorough investigation of the performance of different equations previously proposed in the literature. The correlation results have shown a strong dependence on the expression used to account for the ideal viscosity contribution. Besides size and shape parameters, for each pure component, the model requires only two adjustable parameters per binary system. The binary interaction parameters have been determined by fitting literature viscosity data. More than 350 binary systems, 4619 viscosity data points at 0.1 MPa, have been correlated using this model. The binary systems investigated are re...