The Viscosity and Diffusion Coefficients of the Mixtures of Light Hydrocarbons with Other Polyatomic Gases

Abstract

AbstractThe paper presents new measurements of the viscosity of binary, gaseous mixtures of the three saturated hydrocarbons ethane, propane, and normal‐butane with other polyatomic gases. Specifically, the systems studied are: C2H6‐N2, C2H6‐CO2, C2H6‐CF4, C2H6‐SF6, C3H8‐N2, C3H8‐CO2, n‐C4H10‐N2, and n‐C4H10‐CO2. The measurements have been carried out near atmospheric pressure in the temperature range 25 — 195 °C in a high precision oscillating‐disk viscometer. The accuracy of the reported values of viscosity is estimated as one of ±0.3%. — Our previous work has proved that each of the pure components conforms to the extended law of corresponding states formulated by Kestin, Ro, and Wakeham. The present measurements demonstrate that the same is true for the interactions among unlike pairs of molecules of the pure components. The experimental viscosities are employed to determine the scaling factors σ12 and 12 which secure the optimum representation of the data with the aid of the universal functional of the law of corresponding states. — The measurements also provide values of the binary diffusion coefficients for the eight mixtures studied. For those systems for which direct measurements of the diffusivity are available, the agreement between the two sets of data is within the mutual uncertainty. For the mixtures C2H6‐CF4, C2H6‐SF6, and n‐C4H10‐CO2 the present measurements represent the first determination of the binary diffusion coefficients.