A Novel Approach Towards Unifac-Visco Modelling for Liquid Mixtures : A New Approximate Technique

The group contribution method 'UNIFAC-VISCO' has become popular because of its reliable predictions of dynamic & kinematic viscosities, but suffering from a serious drawback for non-availability of sufficient group interaction parameters. A new approximate technique has been proposed in this study, in which the so called UNIFAC-VLE parameters can be used instead of the original UNIFAC-VISCO parameters. This technique was tested for 28 binary liquid systems of different categories & the values of overall AAD (%) for 7 classes of organic binary liquid systems were found to be below 6.1%. These include alcohols, alkanes, aromatics, ester, cyclic ether, as well as acetonitrile & sulfolane which are yet to be done. Predictions were carried out based on four different considerations: (a) original parameters, (b) UNIFAC-VLE parameters, (c) by considering, or (d) ignoring temperature effects on group interaction parameters. As the UNIFAC-VLE parameters are easily available & applicable for a broad range of organic compounds, its use in place of original model parameters would generalize the UNIFAC-VISCO model for predicting dynamic & kinematic viscosities.