Volumetric behavior of the {CO2 (1) + C2H6 (2)} system in the subcritical (T = 293.15 K), critical, and supercritical (T = 308.15 K) regions.

The volumetric behavior for the {CO2 (1) + C2H6 (2)} system has been studied. Density measurements of {CO2 (1) + C2H6 (2)} binary mixtures at 293.15 and 308.15 K, at several pressures and compositions, and density measurements for infinitely dilute solutions at 304.21 and 308.15 K were carried out using an Anton Paar DMA 512-P vibrating-tube densimeter calibrated with the forced path mechanical calibration model. The mean relative standard deviation of density, s(rho)(r), was estimated to be better than 0.1%, and the uncertainties in temperature and pressure were estimated as +/-0.01 K and +/-0.001 MPa, respectively. In the experimental setup, an uncertainty in the mole fraction of u(x(j)) = +/-0.0015 has been achieved. Other properties related to P-rho-T-x data such as the compressibility factor, Z, excess molar volumes, V(m)(E), and partial molar volumes, V(i) and V(i)(infinity) have been calculated. The volumetric behavior has been compared with literature data and with that obtained from the PC-SAFT EoS rescaled parameters; these parameters have been obtained from our previous experimental values for the critical temperature and pressure of pure compounds. The value for the Krichevskii parameter, A(Kr), was obtained from the experimental density data for infinitely dilute solutions measured in this work, and it has been compared with that obtained from critical properties. Structural properties such as direct and total correlation function integrals and cluster size were calculated using the Krichevskii function concept.