(${p, \rho , T, x}$) Properties of $\text{ CO}_{2}$/Propane Binary Mixtures at 280 K to 440 K and 3 MPa to 200 MPa

Abstract

The (p, $\rho$, T, x) properties of binary mixtures of CO$_{2}$ (volume fraction purity 0.99999) and propane (mole fraction purity 0.9999) ($x_{1}$ CO$_{2}+x_{2}$ propane; $x_{1} = 0.1744$, 0.3863, 0.5837, and 0.7732) were measured in the compressed liquid phase using a metal-bellows variable volumometer. Measurements were conducted from 280 K to 440 K and 3 MPa to 200 MPa. The expanded uncertainties ($k = 2$) were estimated to be temperature, $<$3 mK; pressure, 1.5 kPa ($p\le 7$ MPa), 0.06 % (7 MPa $< p\le 50$ MPa), 0.1 % (50 MPa $< p\le 150$ MPa), 0.2 % ($p> 150$ MPa); density, 0.10 %; and composition, $4.4\times 10^{-4}$. At $p >100$ MPa and 280 K or 440 K, the uncertainties in density measurements increase to 0.14 % and 0.22 %, respectively. The data were compared with available equations of state. The excess molar volumes, $v_\mathrm{m}^\mathrm{E}$, of the mixtures were calculated and plotted as a function of temperature and pressure.