Extensive Study of the Capabilities and Limitations of the CPA and sPC-SAFT Equations of State in Modeling a Wide Range of Acetic Acid Properties

Abstract

The accurate description of many thermodynamic properties of acetic acid and its mixtures can be a challenge to model with standard thermodynamic models such as local-composition activity coefficient models and cubic equations of state. A possible solution is offered by association equations of state, e.g., those belonging to the statistical associating fluid theory (SAFT) family. While several researchers have studied the use of SAFT variants to model acetic acid properties (pure compound and mixtures), with few exceptions, those studies focused exclusively on phase equilibria including vapor pressure and density. Other important properties, such as the speed of sound, second virial coefficient, compressibility factor, enthalpy of vaporization, and isobaric heat capacity have not been considered yet. Few studies investigate which is the appropriate association scheme to be used for acetic acid. In this work, we compare the capabilities of two association models, cubic plus association (CPA) and simplifie...