Multiproperty analysis of PVT, enthalpy and phase equilibrium data

In the most general application yet made of the method, multiproperty analysis was used to determine methane and propane parameters for a modified BWR state equation. Over 1300 mixture and pure component data points for density, enthalpy, vapor pressure and vapor‐liquid equilibrium, from −290°F to 400°F and up to 9,000 psia, were used in the multiproperty repression calculations. The resultant equation of state predicts thermodynamic properties with low average absolute uncertainties: 0.0055 lb‐mole/cu. ft. (0.77%) for density, 1.01 Btu/lb for enthalpy, 0.0147 Btu/lb‐ °F for entropy, 0.62% and 0.63% respectively for methane and propane vapor pressures and 1.67% and 3.73% respectively for methane and propane K‐values.