Vapor-Phase (p, ρ, T, x) Behavior and Virial Coefficients for the (Argon + Carbon Dioxide) System

A two-sinker magnetic suspension densimeter was used to carry out accurate density measurements on binary mixtures (argon + carbon dioxide) with carbon dioxide mole fractions of 0.50000, 0.49975, and 0.75093. The measurements cover a temperature range from T = (273.15 to 323.15) K with pressures up to 9.1 MPa or the dew-point pressure, whichever was lower. The mixtures were prepared gravimetrically. With all measurement uncertainties in temperature, pressure, density, and composition taken into account, the relative combined expanded uncertainty (k = 2) in density was estimated to be less or equal to 0.033%. Relative deviations of the experimental densities from the GERG-2008 equation of state were within 0.31% for the mixtures with 0.50000 and 0.49975 mole fraction carbon dioxide and up to 1.90% for the mixture with 0.75093 mole fraction carbon dioxide. In contrast, the relative deviations from a recently developed multiparameter equation of state (EOS) optimized for combustion gases (EOS-CG) were less t...