(231e) Prediction of Kinematic Viscosities and Vapor-Liquid Equilibria for Ternary Systems Using Activity Coefficient Model

The kinematic viscosity is one of the important transport properties for discussing a lot of chemical processes. Among the predictive methods of kinematic viscosity, the method with excess Gibbs free energy at activated state based on Eyring’s absolute rate theory will be useful from a practical point of view.

   lnηV=Σln(η_iV_i)+G^≠,E/RT

or     lnη/ρ=Σln(η_i/ρ_i)-(lnM-ΣlnM_i)+G^≠,E/RT

where η, ρ, M are the viscosity, density, molecular weight, and  G^≠,E is the excess free energy at activated state and is related with the excess free energy  G^E as follows [1-3]:

   G^≠,E=kG^E

where kdepends on the system, temperature and pressure.

The excess free Gibbs energy is calculated by activity coefficients.

   G^E/RT=Σx_ilnγ_i

This article deals with the correlation of kinematic viscosities and vapor-liquid equilibria for binary systems using NRTL equation. In the model, the binary parameters are NRTL parameters and k. The kinematic viscosities and vapor-liquid equilibria for ternary systems are then predicted using the binary parameters.

References

1) Murata, Tochigi, Yamamoto: Molecular Simulation, 30, 451 (2004)

2) Tochigi, Yoshino, Rattan: Int. J. Thermophysics, 26, 413 (2005)

3) Tochigi, Okamura, Rattan: Pluid Phase Equilibria, 257, 228 (2007)