Thermal conductivity of methane for temperatures between 110 and 310 K with pressures to 70 MPa

The paper presents new experimental measurements of the thermal conductivity of methane for 14 temperatures between 110 and 310 K with pressures to 70 MPa and densities from 0 to 30 mol · L^–1. The measurements were made with a transient hot-wire apparatus and they cover a wide range of physical states including the dilute gas, the moderately dense gas, the near-critical region, the compressed liquid states, and the vapor at temperatures below the critical temperature. The new measurements are closely spaced in temperature and density to describe the thermal conductivity surface, in particular the critical enhancement which extends to the highest temperature measured. A fit of the thermal conductivity surface allows comparison of the present results to those of others. The comparison reveals several discrepancies inherent in the results of others and in an earlier correlation. The precision (2) of the methane measurements is between 0.5 on 0.8 % for wire temperature transients of 4 to 5 K, while the accuracy is estimated to be 1.6%.