Calculating the dynamic viscosity of individual substances using the Peng-Robinson equation

A method for calculating the dynamic viscosity of individual compounds in the liquid and gaseous states has been developed using Eyring and Frankl's "excited zone" formation hypothesis. In this method, the activation energy is estimated in terms of the deviation of the enthalpy of the substance from the ideal-gas approximation. This deviation is calculated using the Peng-Robinson equation f state. The expressions obtained for viscosity contain a constant, whose value is the same for a wide variety of compounds. The results of these calculations are compared with experimental data for the viscosity of liquids and vapors along the saturation line and isobars, including supercritical pressures.