(179b) Modeling the Viscosity of Imidazolium-Based Ionic Liquids from Ambient to High Pressures Using Entropy Scaling and SAFT Equations of State

Ionic liquids have been studied for a wide variety of engineering applications, e.g gas absorption, catalysis, liquid-liquid extraction, etc. Regardless of the end-application, effective process design is dictated by knowledge of the ionic liquid’s transport properties at processing conditions. Several empirical and semi-empirical models have been used to correlate transport properties of common fluids. Entropy scaling is a promising approach that has demonstrated robustness and accuracy in the development of engineering models for transport properties from low to high pressure. Here we propose and compare two different entropy scaling models for the viscosity of imidazolium ionic liquids. A molecular approach is contrasted with an ion-based approach using, respectively, the PC-SAFT and the ePC-SAFT equations of state. Both approaches offer satisfactory correlation of pure ionic liquid’s viscosity over a wide range of temperatures and pressures.