Application of MOSCED To Predict Limiting Activity Coefficients, Hydration Free Energies, Henry’s Constants, Octanol/Water Partition Coefficients, and Isobaric Azeotropic Vapor–Liquid Equilibrium

Abstract

Modified Separation of Cohesive Energy Density (MOSCED) is a solubility parameter-based method to predict limiting activity coefficients. In addition to making quantitative predictions, MOSCED may additionally be used to understand the underlying molecular-level driving forces for intuitive solvent selection and formulation. A major improvement of MOSCED over similar solubility parameter methods is that it splits the association term. We show by example how this change allows MOSCED to better model the molecular interactions of associating fluids. While parametrized to predict limiting activity coefficients, we demonstrate the ability to predict hydration-free energies, Henry’s constants in water, and octanol/water partition coefficients. We focus on water as MOSCED was previously found to perform substantially worse when water was the solvent. Comparison is made to molecular simulation and mod-UNIFAC, and we find for the studied reference set that predictions with MOSCED were in better agreement with exp...