**METHANE**

METHANE provides thermodynamic properties for methane using the fundamental equation of state developed by:

U. Setzmann and W. Wagner,

"*A New Equation of State and Tables of Thermodynamic Properties for Methane Covering the Range from the Melting Line to 625 K at Pressures up to 1000 MPa*",

J. Phys. Chem. Ref. Data, Vol. 20, No. 6, 1991.

The values of specific enthalpy and entropy are by default referred to -0.9889 kJ/kg and -0.002289 kJ/kg-K, respectively at 298.15 K and 101.3 kPa. The reference state can be changed using the $Reference directive.

Transport properties are from B.A. Younglove and J.F. Ely,* "Thermophysical Properties of Fluids. II Methane, Ethane, Propane, Isobutane and Normal Butane"*, J. Phys. Chem. Ref. Data Vol. 16, No. 4, 1987.

__Range of applicability for equation of state and transport functions:__

90.7 K < T < 625 K

0 < P < 1000 MPa

__Surface tension data are provided using the information in:__

Mulero, A., Cachadina, I, and Parra, M.

"Recommended Correlations for the Surface Tension of Common Fluids"

J.Phys. Chem Ref. Data, Vol. 41, No.4, 2012

__The __sublimation pressure__ curve (valid for temperatures between 48 K and 90.694) is determined from:__

N.Fray, B.Schmitt,

"Sublimation of ices of astrophysical interest:A bibliographic review"

Planetary and Space Science,57, (2009) pp. 2053-2080

__The __melting pressure__ curve (valid for temperatures between 90.694 K and 120 K) is determined from:__

U. Setzmann and W. Wagner

"*A New Equation of State and Tables of Thermodynamic Properties for Methane Covering the Range from the Melting Line to 625 K at Pressures up to 1000 MPa*",

J. Phys. Chem. Ref. Data, Vol. 20, No. 6, 1991

Note that METHANE provides thermodynamic properties assuming real fluid behavior. Use CH4 for ideal gas properties of methane consistent with reference states used in combustion calculations.