An extended COSMO-SAC method for the prediction of carboxylic acid solubility

Abstract

The COSMO-SAC model provides a convenient method for predicting the phase behavior of components with minimal information about molecules using quantum-mechanical principles. During the past few years, several researchers tried to improve the prediction capability with modifications to hydrogen bonding terms and other methods of calculation. In this contribution, we focused on carboxylic acid groups, which may exhibit different hydrogen-bond behavior as compared with alcohols. The calculation scheme in COSMO-SAC (2017 version) was slightly modified to encompass a hydrogen-bond term specifc to carboxylic acid groups. The parameters for the extended COSMO-SAC model were fitted using 559 data points. The characteristics of the extended model were investigated for the prediction capability of binary solubility, ternary solubility, and vapor-liquid equilibrium data. The results show that the extension correctly predicts the phase behavior of mixtures containing carboxylic acids. © 2020