Thermodynamics Research Center / ThermoML | Fluid Phase Equilibria

ABSTRACT

New experimental P-rho-T data of three glycols ethers, namely, 2-ethoxyethanol, 2- propoxyethanol and 2-butoxyethanol were measured in a wide range of temperatures (293.15 to 413.15) K and pressures (0.1 to 30) MPa with a vibrating tube densimeter. The experimental P-rho-T data were correlated with the modified Tait equation. The study is completed with modeling in terms of the simplified perturbed-chain statistical associating fluid theory (sPC-SAFT) equation of state. The pure compound parameters of the sPC-SAFT equation are generally determined by fitting the equation to experimental saturated vapor pressure and liquid density data. In this work, by simultaneously minimizing the total objective function of temperature, pressure and density new correlation were developed to estimate the sPC-SAFT equation parameters with two association scheme for three glycols ethers including, 2-ethoxyethanol, 2-propoxyethanol and 2-butoxyethanol by using P-rho-T data and with a fitting AAD% of 0.17 on average. The validity of the parameters and the employed association scheme were tested by the evaluation of densities and derivative properties such as isobaric thermal expansion coefficients, pounds, isothermal compressibility, isobaric heat capacities, and speed of sound. All correlated/predicted results were compared with the modified Tait equation and experimental literature data. The obtained results showed that the sPC-SAFT equation of state, along with the proposed correlations, presents good results for modeling these glycols ethers.