Entropy Scaling of Viscosity for Imidazolium Ionic Liquids with Dissolved Refrigerants Based on the Soft-SAFT Equation of State

The mixtures of ionic liquid/refrigerant are a promising
working
pair in absorption refrigeration, their viscosity, which is crucial
for process design, changes significantly with composition and operating
conditions, making existing models inadequate. This study presents
an extended application of entropy scaling theory coupled with the
soft-SAFT equation of state for viscosity estimation in pure imidazolium-based
ionic liquids (ILs) and their mixtures with refrigerants. The methodology
was validated through a comprehensive analysis of 4,265 experimental
viscosity data points for pure ILs over a wide range of temperatures
and pressures, achieving an average absolute relative deviation (AARD)
of 5.76% between calculated and experimental values. When the model
was extended to IL/refrigerant mixtures, a modified Grunberg–Nissan
mass mixing rule was employed, resulting in an AARD of 12.84% across
248 experimental data points.