The composition shifts of multicomponent mixtures used in low temperature Joule-Thomson refrigerators due to the different solubility in lubricant oils are studied in this paper. A compound of squalane with a high-boiling point temperature is treated as a kind of mineral oil. The Peng-Robinson (PR) equation of state (EOS) is selected to predict the solubilities, in which a group contribution mo...

A new apparatus for the study of vapor-liquid or vapor-liquid-liquid equilibrium has been assembled. The apparatus, based on a static and analytical method, can perform measurements at temperatures from 185 to 320 K and pressures up to 8 MPa. The equilibrium vapor pressures of (xenon + methane) binary mixtures have been measured at seven temperatures, from 189.78 to 273.18 K, and at pressures u...

In this work is examined whether it is possible to predict solid-liquid-vapor phase equilibrium of ternary systems used in the SAS processing by the Peng-Robinson equation of state coupled with the LCVM mixing rules and the UNIFAC method for excess Gibbs free energy calculation. The enthalpy of fusion and the melting point temperature are estimated by group contribution methods. The results sho...

Abstract: A thermodynamic consistency test developed for high pressure binary vapor-liquid mixtures is applied to mixtures containing a supercritical solvent and an ionic liquid. Several authors have reported vapor-liquid equilibrium data on the binary systems supercritical CO2 + 1-butyl-3-methyl imidazolium hexafluorophosphate {[bmim][PF6]}, supercritical CO2 + 1-butyl-3-methyl imidazolium nit...

−Computer simulations were performed to obtain highly pure tetrahydrofuran (THF) with over 99.9 mole% from the mixture of THF and water. Pressure swing distillation (PSD) was used since the azeotropic point between tetrahydrofuran and water can be varied with pressure. A commercial process simulator, PRO/II with PROVISION release 8.3, was used for the simulation studies. The Wilson liquid activ...

In biodiesel production processes using supercritical methanol, the phase equilibria for methanol + fatty acid methyl ester systems near the critical temperature of methanol (Tc = 512.6 K) are required as the fundamental data. A flow type method was applied to measure the vapor-liquid equilibria for methanol + fatty acid methyl ester binary systems at 493 – 543 K. The phase behavior was studied...

Based on biologically inspired algorithms, a thermodynamic model to describe the vapor-liquid equilibrium of binary complex mixtures containing supercritical fluids and ionic liquids, is presented. The Peng-Robinson equation of state with the Wong-Sandler mixing rules are used to evaluate the fugacity coefficient on the systems. Then, a hybrid particle swarm-ant colony optimization was used to ...

We propose a density-functional theory (DFT) describing inhomogeneous polymer-carbon dioxide mixtures based on a perturbed-chain statistical associating fluid theory equation of state (PC-SAFT EOS). The weight density functions from fundamental measure theory are used to extend the bulk excess Helmholtz free energy to the inhomogeneous case. The additional long-range dispersion contributions ar...

Air is one of the most important substances used in industrial and technological applications. Applications air require a consistent set reliable data on its thermodynamic thermophysical properties. Over last few decades, researchers have developed number empirical theoretical models for correlation prediction properties pure fluids mixtures. The ideal gas Equation State (EoS) property calculat...