Extension of a Group Contribution Method to Predict Viscosity Based on Momentum Transport Theory Using a Modified Peng–Robinson EoS

In this work, a semitheoretical model
based on the momentum transport
theory is generalized through the development of a group contribution
method. Viscosity data for temperatures between 13.95 and 950 K and
pressures from 1.00 × 10–3 bar up to 1.00 ×
104 bar were used to develop and to validate the model.
To perform viscosity calculations, the model requires density and
residual enthalpy that were obtained from a modified Peng–Robinson
equation of state. Also, the model has one adjustable parameter that
can be estimated form the group contribution method. Viscosity was
calculated for 256 substances including 95 non-polar and 161 polar
compounds. In total, 23 organic families were considered. Average
deviations below 6.67% were calculated. The performance of the model
was compared with those of other models reported in the literature.
Calculations were carried out to include the saturation and single-phase
regions. In general, it can be considered that the proposed model
describes viscosity adequately using only one adjustable parameter.