“Vapor–liquid” equilibrium measurements and modeling for the cyclohexane + n-hexanoic acid binary system

• Published in: Fluid phase equilibria 2011-10, Vol.309 (1), p.15-19
• Main Authors: Valtz, Alain, Soo, Chien-Bin, Coquelet, Christophe, Richon, Dominique, Amoros, Daniel, Gayet, Hubert
• Format: Article
• Language: English
• Subjects: Chemistry; Cyclohexane; Equation of states; Exact sciences and technology; General and physical chemistry; High-pressure; Liquid-vapor equilibria; n-Hexanoic acid; PC-SAFT; Phase equilibria; PR-EoS; “Static-analytic” method; “Vapor–liquid” equilibrium data
• ISSN: 0378-3812; 1879-0224
• DOI: 10.1016/j.fluid.2011.06.027

• We determine new experimental data concerning the cyclohexane + n-hexanoic acid binary system. • An equipment based on “static analytic” method with phase sampling is used. • Two models are compared for the data treatment. • Data and models are used for the design of phase separation units on the Rhodia site. To simulate cyclohexane to cyclohexanol oxidation reactors, the acquisition and modeling of vapor–liquid equilibria of the key components, under the process conditions, are essential. n-Hexanoic acid is a co-product of the reaction. Vapor–liquid equilibrium data are reported for the cyclohexane + n-hexanoic acid binary system at four temperatures: 413, 423, 464 and 484 K. All measurements have been carried out using an apparatus based on the “static-analytic” method, with two ROLSI™ pneumatic capillary samplers. The generated data are successfully correlated using two equations of state, the Peng–Robinson (PR) and the Perturbed Chain Statistical Association Fluid Theory (PC-SAFT). Both models are capable of representing the experimental data, but the PC-SAFT EoS uses less binary interaction parameters.