The Specific Heats, C , and C , of Compressed and Liquefied Methane

The specific heats, C , of saturated liquid methane have been measured at 66 temperatures in the temperature range 95-187 K. The specific heats at constant volume, C , have been measured at 20 densities ranging from 0.8 to 2.8 times the critical density, at temperatures between 91 and 300 K, and at pressures to 330 bar (at 280 PVT states in all). The uncertainty of most of the measurements is estimated to be less than 0.5 percent, except near the critical point. These measurements were performed primarily to provide input data for accurate thermodynamic properties data calculations for liquid methane. They are believed to be the most comprehensive specific heat measurements available for pure compressed gaseous and liquid methane.