Thermal conductivity of mixtures in the dense gaseous state: The methane-carbon tetrafluoride system

Abstract

Using a coaxial cylindrical cell, thermal conductivities were measured for gaseous methane, carbon tetrafluoride, and three of their mixtures. The nominal temperatures used were 60, 100, 130, and 160°C and pressures from approximately 3 atm up to 680 atm. The experimental values when correlated as residual thermal conductivities, k − k ∗, against density showed a slight temperature dependence which decreased with increasing methane concentrations. When this temperature dependence was accounted for, the thermal conductivities of methane, carbon tetrafluoride, and their three mixtures were found to be consistent with the method outlined in the literature which relates ( k − k ∗)λ z 5 c with ϱ R . The experimental values obtained in this study for the methane-carbon tetrafluoride system produced with reduced density a unique relationship which reproduces 215 experimental values with an average deviation of 2.55%.