Densities and dielectric permittivities for (carbon monoxide + carbon dioxide) mixtures determined with a microwave re-entrant cavity resonator. (February 2019)

• Record Type: Journal Article
• Authors: Tsankova, Gergana; Richter, Markus; Stanwix, Paul L.; May, Eric F.
• Is Part Of: Journal of chemical thermodynamics. Volume 129(2019)
• Page Start: 114
• Page End: 120
• Publication Date: 2019-02
• Subjects: Carbon monoxide -- Carbon dioxide -- Dielectric permittivity -- Mixture composition -- Mixture density -- Microwave re-entrant cavity resonator; Thermodynamics -- Periodicals; Thermochemistry -- Periodicals; Thermodynamique -- Périodiques; Thermochimie -- Périodiques; Thermochemistry; Thermodynamics; Periodicals; 541.369
• DOI: 10.1016/j.jct.2018.09.010
• Languages: English
• ISSNs: 0021-9614

Abstract

Highlights: Dielectric permittivities of CO + CO2 mixtures measured with a re-entrant cavity resonator. Measurements were made at temperatures from (255.05 to 313.28) K and pressures to 8 MPa. The permittivity data allowed a 15-fold reduction in the mixtures' composition uncertainties. Harvey-Prausnitz mixing rule used to extract densities from permittivities to 0.5% uncertainty. Abstract: A microwave re-entrant cavity resonator apparatus was used for the determination of dielectric permittivity, mole fraction composition and molar density of two binary (CO + CO2 ) mixtures, with CO2 mole fractions of approximately 0.25 and 0.50. The dielectric permittivity was measured with a relative combined expanded uncertainty ( k = 2) less than or equal to 0.13% over the temperature range from T = (255.05 to 313.28) K at pressures up to 8 MPa. The new dielectric permittivity data were used together with the pure fluid polarizability correlations to reduce the uncertainty in the mixture's mole fraction composition by factor of 15 relative to that provided by the supplier. Moreover, by applying the Harvey-Prausnitz mixing rule, we determined the mixture molar densities from measured permittivities to within 0.53% ( k = 2) in a previously unstudied region. The new mixture density data near 6 MPa agree within 1.4% of predictions made with the multi-parameter equation of state optimized for combustion gases (EOS-CG). Comparison of these data with the EOS-CG and literature density values show that mixture density determinations based on dielectric permittivity measurements and the Harvey-Prausnitz mixing rule can also be accurate for gas mixtures containing appreciable amounts of a polar substance.