Recent applications of the cubic-plus-association (CPA) equation of state to industrially important systems

The cubic-plus-association equation of state (CPA EoS) has been extended to phase equilibria of industrially important binary mixtures of alcohol–hydrocarbon, alcohol/glycol–water systems and mixtures with organic acids. The ability of the model to predict different types of equilibria was tested. Very satisfactory VLE and SLE prediction is achieved for alcohol–hydrocarbon systems, while the sensitivity of the LLE to the interaction parameter is demonstrated. It has been shown that CPA can perform VLE/LLE/SLE calculations in the case of alcohol–hydrocarbon binary systems with a single interaction parameter. Satisfactory SLE correlation of alcohol/glycol–water systems is achieved using a single interaction parameter over an extended temperature range. Moreover, satisfactory prediction was achieved for the multiphase equilibria of the mixture acetic acid–water–hexane based solely on binary interaction parameters.