Thermal conductivities of gaseous alkane + perfluoroalkane mixtures

Abstract

The thermal conductivities of eleven gaseous alkane + perfluoroalkane mixtures have been measured as a function of composition at 303.0 K. The experimental results are consistent with the proposed weakness in the hydrocarbon-perfluorocarbon interaction energy that has been suggested by several independent equilibrium studies. Predictions from the Hirschfelder–Eucken equation are generally lower than experiment as a result of relaxation effects. However, attempts to correct for the influence of relaxation on the heat transport are hindered, mostly by uncertainties in the assignment of the collision numbers. Included in the results are the following values of the thermal conductivies (in mW m^–1 K^–1) of the pure component gases at 303.0 K: CH₄, 34.94; C₂H₆, 22.20; C₃H₈, 18.59; n-C₄H₁₀, 16.52; CF₄, 16.23; C₂F₆, 14.56; C₃F₈, 13.40.