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Speed of Sound Measurements in (Argon + Carbon Dioxide) over the Temperature Range from (275 to 500) K at Pressures up to 8 MPa



Mark O. McLinden, Richard A. Perkins, Robin Wegge, Markus Richter, Roland Span


The speed of sound of two (argon + carbon dioxide) mixtures was measured over the temperature range from (275 to 500) K with pressures up to 8 MPa utilizing a spherical acoustic resonator. The compositions of the gravimetrically prepared mixtures were (0.50104 and 0.74981) mole fraction carbon dioxide. The vibrational relaxation of pure carbon dioxide leads to high sound absorption, which significantly impeded the sound speed measurements on carbon dioxide and its mixtures; precondensation may have also affected the results for some measurements near the dew line. Thus, in contrast to the standard operating procedure for speed of sound measurements with a spherical resonator, non-radial resonances at lower frequencies were taken into account. Still, the data show a comparatively large scatter, and the usual repeatability of this general type of instrument could not be realized with the present measurements. Nonetheless, the average relative combined expanded uncertainty (k = 2) in speed of sound ranged from (0.042 to 0.056)% for both mixtures, with individual state-point uncertainties going up to 0.1%. These uncertainties are adequate for our intended purpose of evaluating thermodynamic models. The results are compared to a Helmholtz energy equation of state for carbon capture and storage applications; relative deviations of (-0.64 to 0.08)% for the (0.49896 argon + 0.50104 carbon dioxide) mixture, and of (-1.52 to 0.77)% for the (0.25019 argon + 0.74981 carbon dioxide) mixture were observed.
Journal of Chemical Thermodynamics


argon, carbon capture and storage, carbon dioxide, spherical resonator, speed of sound


McLinden, M. , Perkins, R. , Wegge, R. , Richter, M. and Span, R. (2016), Speed of Sound Measurements in (Argon + Carbon Dioxide) over the Temperature Range from (275 to 500) K at Pressures up to 8 MPa, Journal of Chemical Thermodynamics, [online], (Accessed April 20, 2024)
Created March 23, 2016, Updated June 2, 2021