scope:

Part 2 presents information for computation of thermodynamic properties, including compressibility factors, densities, and speeds of sound, of natural gas and related gases, for gaseous states, vapor-liquid equilibrium states, and liquid states, based on the GERG-2008 equation of state [1,2]. It also improves upon the performance of the AGA 8 DETAIL equation [3] for gas-phase properties, especially at high pressures and low temperatures. The ranges of temperature, pressure, and composition for which the GERG-2008 equation of state applies are much wider than the AGA 8 DETAIL equation. Uncertainty estimations for different compositions, pressures, and temperatures are given. With the availability of vapor-liquid equilibrium and liquid state calculations, Part 2 enables the calculation of dew points, bubble points, and the critical point.