Isothermal vapor–liquid equilibrium data for the carbon dioxide (R744) + decafluorobutane (R610) system at temperatures from 263 to 353 K

Isothermal vapor–liquid equilibrium data are presented for the carbon dioxide (CO2) + decafluorobutane (C4F10) system. Measurements were performed for seven isotherms (three isotherms below and four above the critical temperature of CO2) ranging from 263.15 to 352.98 K, with pressure ranging from 0.0727 to 6.8628 MPa. The measurements were undertaken using a “static-analytic” type apparatus, with sampling of the equilibrium phases via pneumatic capillary samplers (ROLSI™, Armine's patent). The apparatus, as well as the samplers was developed in the CEP/TEP laboratory. The maximum uncertainties in the measurements were within ±0.02 K, ±0.0006 MPa and ±2.5% (relative) for temperature, pressure, and equilibrium phase mole fractions, respectively. The full set of isothermal vapor–liquid equilibrium data were correlated with the Peng–Robinson equation of state, incorporating the Mathias–Copeman alpha function, with the Wong–Sandler mixing rule utilizing the NRTL activity coefficient model. These measurements have also been compared to results obtained from molecular simulation using the Gibbs ensemble Monte Carlo method.

Research highlights
► Isothermal VLE measured for CO2 + decafluorobutane.
► Measurements for T = 263.15–353.98 K and P = 0.0727–6.8628 MPa.
► Experimental data correlated with appropriate equation of state.
► Gibbs ensemble Monte Carlo simulations compared to experimental data.