Experimental enthalpy determinations made on three methane-ethane binaries and one methane-ethane-propane ternary have been interpreted and smoothed. The resulting enthalpy values are thermodynamically self-consistent over the experimental range roughly -240 to +300 °F at pressures up to 2000 psia. Smoothed enthalpy values are presented in tabular form at the temperatures and pressures of measurement. Values of smoothed derivative functions are also given in the tables: Cp values corresponding to isobaric determinations and ɸ = (dH/dP)T values derived from both isothermal and isenthalpic experiments. The smoothed values are probably accurate to ±1% which makes them adequate to test most engineering correlations. The derivative properties are somewhat less accurate, ±2%, with larger deviations near the critical point of the mixtures. The most firmly established enthalpy values are included in Table I. These extend over the greater portion of the range of temperatures and pressures investigated and should be particularly suited to testing methods of predicting enthalpy both because of their accuracy and because of their scope. The original experimental data have been placed on file in the microfilm edition. © 1979, American Chemical Society. All rights reserved.
