Isothermal Vapor–Liquid Equilibrium Data for the Hexafluoroethane (R116) + n-Butane System at Temperatures from 273 to 323 K

Abstract

Isothermal vapor−liquid equilibrium (VLE) data for the system of hexafluoroethane (R-116) + n-butane are reported in this paper. The measurements were undertaken at six different temperatures ranging from 273.27 to 323.19 K, with pressure ranging from 0.104 to 3.742 MPa. Two of the temperature sets were measured below, and the remaining four were measured above, the critical temperature of R116. The measurements were performed in a "static-analytic" type VLE apparatus. The sampling of the equilibrium phases was performed via pneumatic ROLSI capillary samplers (Armine's patent). The equipment was developed in the CEP/TEP laboratory at MINES ParisTech. Combined expanded uncertainties in the measurements were estimated to be 0.02 K for temperature, 0.0006 MPa for pressure, and maximum of 0.004 for composition, based on the NIST guidelines. Each set of isothermal vapor−liquid equilibrium data was correlated with the Peng−Robinson equation of state (PR-EOS). The Mathias−Copeman alpha function, and the Wong−Sandler mixing rule, utilizing the nonrandom twoliquid activity coefficient model, were incorporated into this equation of state.

Isothermal Bubble Pressure Data for the Binary System of C2F6 and n-Octane

“…System pressure as a function of the number of carbon atoms in the n -alkane molecule for systems of R-116 + (C 3 to C 10 ) n -alkanes at a R-116 molar composition ( x 1 ) of 0.1 and at temperatures of between T = (292.94 and 296.24) K. Data were sourced from this work as well as the works of Ramjugernath et al ,, and Williams-Wynn et al , …”

“…However, the discrepancies between the data and the models were high with AARD values between 5.5 and 7.2%. Despite the fit of the models not being as accurate as in the case of other systems involving hexafluoroethane and an alkane, ,,,, the PR MC + WS/NRTL model was used here to ensure that parameters for this model were available for all of the measured systems in the homologous series of R-116 + n -alkanes. The parameters that are presented in Table are also plotted in Figure .…”

“…The thermodynamic models also make it possible to optimize the process by performing multiple process simulations under different process conditions. The most commonly utilized ‘model systems’ contain species from the homogeneous n -alkane series. ,, A number of binary systems involving trifluoromethane, hexafluoroethane, and n -alkanes have been investigated in previous studies. − The experimental data for the system of hexafluoroethane (R-116, perfluoroethane) + n -octane measured in this study are a continuation of the representative measurements for the characterization of R-116 as a supercritical solvent.…”

Isothermal Vapor–Liquid Equilibrium Data for Binary Mixtures of Hexafluoroethane (R116) + n-Pentane or n-Hexane at Two Temperatures, 288 and 296 K

“…There has been little reported in the open literature on studies related to the use of fluorinated refrigerants as solvents for hydrocarbon systems. A partial list of authors who have reported the vapor–liquid equilibrium (VLE) data of hexafluoroethane (R-116) with n -alkanes was supplied by Ramjugernath et al Authors who have reported VLE measurements of hexafluoroethane and alkanes include Ramjugernath et al , and Zhang et al. , The system of R-116 and ethane was investigated by Zhang et al, whereas VLE data sets for the system of R-116 with both propane and n -butane were investigated by Ramjugernath et al…”

Experimental determination of the critical loci for R-23+(n-propane or n-hexane) and R-116+n-propane binary mixtures

“…[8]. For the R-23 + n-hexane system, the data of Williams-Wynn et al [4] were used, and for the R-116 + n-hexane, the data that were reported by Ramjugernath et al [9] were extrapolated to the critical point.…”