224

P-PROPATH: Pure Substances and Mixtures with Fixed Composition

2.23 Methane(IUPAC Table)
Equations for thermodynamic properties have been cited from the IUPAC Table [1], and those for viscosity
from Ely et al.[2], thermal conductivity from reference [3] and surface tension from Miller et al.[4].

2.23.1 Temperature Scale
International practical temperature scale 1968 (IPTS-1968)

2.23.2 The Names of Substance, Library File and Single Shot Program
Name of Substance:
Library File for UNIX:
Library File for DOS,Windows95/NT:
Single Shot Program for UNIX:
Single Shot Program for DOS,Windows95/NT:

Methanelibjch4.a
JCH4.LIB
ch4-ss
CH4–SS.EXE

2.23.3 Important Constants and Others
Molecular Formula:
Relative Molecular Mass:
Gas Constant:

CH4
16.043518.25 J/(kg·K)

Critical Constants:
Critical Pressure:
Critical Temperature:
Critical Speciﬁc Volume:4.595×10 6Pa (45.95 bar)190.555 K (−82.595 ◦C)
6.1656×10 −3m3 /kg

Triple Point:
Pressure:
Temperature:

0.011719×10 6Pa (0.11719 bar)90.68 K (−182.47 ◦C)

Reference State:
The point at which the speciﬁc entropy and the speciﬁc enthalpy are assumed to be zero is that of the ideal
gas at 25 ◦ C(298.15 K) and 1.01325 bar (1 atm).

2.23.4 Formula
Equation of State:
Equation (24) in a function form of P = P (ρ, T ) in reference [1]. Here P =pressure, ρ=density and T =temperature.
However the minus sign of the coeﬃcient N32 in the Table G in reference [1] has been corrected to a plus sign.
Vapor Pressure:
Equation (50) in reference [1].
Properties at Vapor-Liquid Equilibrium:
Equation (24) for speciﬁc volume, equations (24) and (27) for speciﬁc entropy, equations (24) and (36)for speciﬁc enthalpy, and equations (24) and (43) for isobaric speciﬁc heat, respectively. All of these havebeen cited from reference [1]. However, the value of f8 =0.269386063023×10 in Table J has been corrected as
f8 =−0.145719286035×10 −10. Further the third term in the right side of equation (43),32

Cp (ρ, T ) = Cpid(T ) − R + R[

Ni (XC)i ]w
0 +···
i=1

Methane(IUPAC Table)

225

has been corrected to32

Cp (ρ, T ) = Cpid(T ) − R − R[

Ni (XC)i ]w
0 +···
i=1

Pressure and Temperature on Melting Line:
Equation (52) in the reference [1].
Transport Properties:
Equation in Table III in reference [2] for viscosity and equation (4) in reference [3] for thermal conductivity.
The Other Properties:
Equation (23-1) in reference [4] for surface tension.

References[1] S.Angus and K.M.de Reuck, International Thermodynamic Table of the Fluid State-5 Methane, IUPAC,
vol.5, (1976).
[2] J.F.Ely and H.J.M.Hanley, Ind. Eng. Chem. Fundam., vol.20, No.4, (1981), p.323.
[3] Survey of Physical Data, High Pressure Fluids, vol.5, Science and Technology Agency, Tokyo, (1977-3),
p.97.
[4] J.W.Miller,Jr. and C.L.Yaws, Chem. Eng., 83-23, (1976), p.127.

226

P-PROPATH: Pure Substances and Mixtures with Fixed Composition
Table II–2.23–1

No.
1
94

Name of
Function
AIPPT(P,T)
AJTPT(P,T)

Methane Function

Function and Argument(s)AJTPT: Joule-Thomson Coeﬃcient [K/Pa]P∗: Pressure [Pa], [bar]T∗: Temperature [K], [◦ C]

Range of Argument(s)11.719×103 ≤P≤40×106 [Pa]TMLP(P)≤T≤620 [K]
40×106 <P≤109 [Pa]TMLP(P)≤T≤470 [K]
0.11719≤P≤400 [bar]TMLP(P)≤T≤346.85 [◦ C]
400<P≤10000 [bar]TMLP(P)≤T≤196.85 [◦ C]

8A
8B
82

AKPD(P)AKPDD(P)AKPT(P,T)

AKPT: Isentropic Exponent [–]P∗: Pressure [Pa], [bar]T∗: Temperature [K], [◦ C]

11.719×103 ≤P≤40×106 [Pa]TMLP(P)≤T≤620 [K]
40×106 <P≤109 [Pa]TMLP(P)≤T≤470 [K]
0.11719≤P≤400 [bar]TMLP(P)≤T≤346.85 [◦ C]
400<P≤10000 [bar]TMLP(P)≤T≤196.85 [◦ C]

8C
8D
2
3
4

AKTD(T)
AKTDD(T)
ALAPP(P)
ALAPT(T)
ALHP(P)

5

ALHT(T)

6
7
8

ALMPD(P)ALMPDD(P)
ALMPT(P,T)

ALHP: Latent Heat of Vaporization [J/kg]
P∗: Pressure [Pa], [bar]ALHT: Latent Heat of Vaporization [J/kg]
T∗: Temperature [K], [◦ C]

11.719×103 ≤P≤4.595×106 [Pa]0.11719≤P≤45.95 [bar]90.68≤T≤190.555 [K]−182.47≤T≤−82.595 [◦C]

ALMPT: Thermal Conductivity [W/(m·K)]
P∗: Pressure [Pa], [bar]T∗: Temperature [K], [◦ C]

100×103 ≤P≤70×106 [Pa]298.15≤T≤423.15 [K]
1.0≤P≤700 [bar]25≤T≤150 [◦ C]

9
10
11

ALMTD(T)ALMTDD(T)
AMUPD(P)12

AMUPDD(P)AMUPD: Coeﬃcient of Viscosity of
Saturated Liquid [Pa·s]
P∗: Pressure [Pa], [bar]
AMUPDD: Coeﬃcient of Viscosity of
Saturated Vapor [Pa·s]
P∗: Pressure [Pa], [bar]PST(95K)≤P≤4.595×106 [Pa]PST(−178.15◦ C)≤P≤45.95 [bar]PST(95K)≤P≤4.595×106 [Pa]PST(−178.15◦ C)≤P≤45.95 [bar]Methane(IUPAC Table)

227
Table II–2.23–1

No.
13

Name of
Function
AMUPT(P,T)

14

AMUTD(T)15

AMUTDD(T)92

BPPT(P,T)

90

91

93

BSPT(P,T)

BTPT(P,T)

BVPT(P,T)

Methane Function (cont’d)

Function and Argument(s)AMUPT: Coeﬃcient of Viscosity [Pa·s]
P∗: Pressure [Pa], [bar]T∗: Temperature [K], [◦C]

AMUTD: Coeﬃcient of Viscosity of
Saturated Liquid [Pa·s]
T∗: Temperature [K], [◦C]
AMUTDD: Coeﬃcient of Viscosity of
Saturated Vapor [Pa·s]
T∗: Temperature [K], [◦C]
BPPT: Volumetric Coeﬃcient of Expansion [1/K]
P∗: Pressure [Pa], [bar]T∗: Temperature [K], [◦C]

BSPT: Isentropic Compressibility [1/Pa]
P∗: Pressure [Pa], [bar]T∗: Temperature [K], [◦C]

BTPT: Isothermal Compressibility [1/Pa]
P∗: Pressure [Pa], [bar]T∗: Temperature [K], [◦C]

BVPT: Pressure Coeﬃcient [1/K]
P∗: Pressure [Pa], [bar]T∗: Temperature [K], [◦C]

Range of Argument(s)100×103 ≤P≤PMLT(95K) [Pa]95≤T≤500 [K]
PMLT(95K)<P≤40×106 [Pa]TMLP(P)≤T≤500 [K]
40×106 <P≤50×106 [Pa]TMLP(P)≤T≤470 [K]
50×106 <P≤75×106 [Pa]205≤T≤470 [K]
1.0≤P≤PMLT(−178.15◦ C) [bar]−178.15≤T≤226.85 [◦C]
PMLT(−178.15◦ C)<P≤400 [bar]TMLP(P)≤T≤226.85 [◦ C]
400<P≤500 [bar]TMLP(P)≤T≤196.85 [◦ C]
500<P≤750 [bar]−68.15≤T≤196.85 [◦C]
95≤T≤190.555 [K]−178.15≤T≤−82.595 [◦C]
95≤T≤190.555 [K]−178.15≤T≤−82.595 [◦C]
11.719×103 ≤P≤40×106 [Pa]TMLP(P)≤T≤620 [K]
40×106 <P≤109 [Pa]TMLP(P)≤T≤470 [K]
0.11719≤P≤400 [bar]TMLP(P)≤T≤346.85 [◦ C]
400<P≤10000 [bar]TMLP(P)≤T≤196.85 [◦ C]
11.719×103 ≤P≤40×106 [Pa]TMLP(P)≤T≤620 [K]
40×106 <P≤109 [Pa]TMLP(P)≤T≤470 [K]
0.11719≤P≤400 [bar]TMLP(P)≤T≤346.85 [◦ C]
400<P≤10000 [bar]TMLP(P)≤T≤196.85 [◦ C]
11.719×103 ≤P≤40×106 [Pa]TMLP(P)≤T≤620 [K]
40×106 <P≤109 [Pa]TMLP(P)≤T≤470 [K]
0.11719≤P≤400 [bar]TMLP(P)≤T≤346.85 [◦ C]
400<P≤10000 [bar]TMLP(P)≤T≤196.85 [◦ C]
11.719×103 ≤P≤40×106 [Pa]TMLP(P)≤T≤620 [K]
40×106 <P≤109 [Pa]TMLP(P)≤T≤470 [K]
0.11719≤P≤400 [bar]TMLP(P)≤T≤346.85 [◦ C]
400<P≤10000 [bar]TMLP(P)≤T≤196.85 [◦ C]

228

P-PROPATH: Pure Substances and Mixtures with Fixed Composition
Table II–2.23–1

No.
16

Name of
Function
CPPD(P)

17

CPPDD(P)18

CPPT(P,T)

19

CPTD(T)

20

CPTDD(T)21

CRP(‘A’)

7A
76

CVPD(P)
CVPDD(P)77

CVPT(P,T)

Methane Function (cont’d)

Function and Argument(s)CPPD: Isobaric Speciﬁc Heat of Saturated
Liquid [J/(kg·K)]
P∗: Pressure [Pa], [bar]
CPPDD: Isobaric Speciﬁc Heat of Saturated
Vapor [J/(kg·K)]
P∗: Pressure [Pa], [bar]CPPT: Isobaric Speciﬁc Heat [J/(kg·K)]
P∗: Pressure [Pa], [bar]T∗: Temperature [K], [◦C]

CPTD: Isobaric Speciﬁc Heat of Saturated
Liquid [J/(kg·K)]
T∗: Temperature [K], [◦C]
CPTDD: Isobaric Speciﬁc Heat of Saturated
Vapor [J/(kg·K)]
T∗: Temperature [K], [◦C]
CRP: Critical Constants
H: ‘A’=‘H’: −492.05×103 [J/kg] Speciﬁc EnthalpyP∗: ‘A’=‘P’: 4.595×106 [Pa], 45.95 [bar] Pressure
S: ‘A’=‘S’: −4.098×103 [J/(kg·K)] Speciﬁc EntropyT∗: ‘A’=‘T’: 190.555 [K], −82.595 [◦C] Temperature
V: ‘A’=‘V’: 6.1656×10−3 [m3 /kg] Speciﬁc Volume
CVPDD: Isochoric Speciﬁc Heat of Saturated
Vapor [J/(kg·K)]
P∗: Pressure [Pa], [bar]CVPT: Isochoric Speciﬁc Heat [J/(kg·K)]
P∗: Pressure [Pa], [bar]T∗: Temperature [K], [◦C]

Range of Argument(s)11.719×103 ≤P≤4.595×106 [Pa]0.11719≤P≤45.95 [bar]11.719×103 ≤P≤4.595×106 [Pa]0.11719≤P≤45.95 [bar]11.719×103 ≤P≤40×106 [Pa]TMLP(P)≤T≤620 [K]
40×106 <P≤109 [Pa]TMLP(P)≤T≤470 [K]
0.11719≤P≤400 [bar]TMLP(P)≤T≤346.85 [◦ C]
400<P≤10000 [bar]TMLP(P)≤T≤196.85 [◦ C]
90.68≤T≤190.555 [K]−182.47≤T≤−82.595 [◦ C]
90.68≤T≤190.555 [K]−182.47≤T≤−82.595 [◦ C]
one of ‘H’, ‘P’, ‘S’, ‘T’ and ‘V’

11.719×103 ≤P≤4.595×106 [Pa]0.11719≤P≤45.95 [bar]11.719×103 ≤P≤40×106 [Pa]TMLP(P)≤T≤620 [K]
40×106 <P≤109 [Pa]TMLP(P)≤T≤470 [K]
0.11719≤P≤400 [bar]TMLP(P)≤T≤346.85 [◦ C]
400<P≤10000 [bar]TMLP(P)≤T≤196.85 [◦ C]

7B
78

CVTD(T)
CVTDD(T)

2A
2B
22
2C
2D
89

EPSPD(P)EPSPDD(P)EPSPT(P,T)
EPSTD(T)EPSTDD(T)FC(‘A’)9A
96

GAMPD(P)GAMPDD(P)

CVTDD: Isochoric Speciﬁc Heat of Saturated
Vapor [J/(kg·K)]
T∗: Temperature [K], [◦C]

90.68≤T≤190.555 [K]−182.47≤T≤−82.595 [◦ C]

FC: Fundamental Constants
M: ‘A’=‘M’: 16.043 Relative Molecular Mass
R: ‘A’=‘R’: 518.25 [J/(kg·K)] Gas Constant

one of ‘M’ and ‘R’

GAMPDD: Ratio of Speciﬁc Heats of Saturated
Vapor [–]P∗: Pressure [Pa], [bar]11.719×103 ≤P≤4.595×106 [Pa]0.11719≤P≤45.95 [bar]Methane(IUPAC Table)

229
Table II–2.23–1

No.
95

Name of
Function
GAMPT(P,T)

Methane Function (cont’d)

Function and Argument(s)GAMPT: Ratio of Speciﬁc Heats [–]P∗: Pressure [Pa], [bar]T∗: Temperature [K], [◦ C]

Range of Argument(s)11.719×103 ≤P≤40×106 [Pa]TMLP(P)≤T≤620 [K]
40×106 <P≤109 [Pa]TMLP(P)≤T≤470 [K]
0.11719≤P≤400 [bar]TMLP(P)≤T≤346.85 [◦ C]
400<P≤10000 [bar]TMLP(P)≤T≤196.85 [◦ C]

9B
97

GAMTD(T)GAMTDD(T)23

HPD(P)

24

HPDD(P)71

HPS(P,S)

25

HPT(P,T)

26

HPX(P,X)

27

HTD(T)28

HTDD(T)

29

HTX(T,X)

84

IDENTF(‘A’)

66
68

PLDT(T)
PMLT(T)

85
86

PRPD(P)PRPDD(P)GAMTDD: Ratio of Speciﬁc Heats of Saturated
Vapor [–]T∗: Temperature [K], [◦ C]
HPD: Speciﬁc Enthalpy of Saturated Liquid [J/kg]
P∗: Pressure [Pa], [bar]HPDD: Speciﬁc Enthalpy of Saturated Vapor [J/kg]
P∗: Pressure [Pa], [bar]HPS: Speciﬁc Enthalpy [J/kg]
P∗: Pressure [Pa], [bar]S: Speciﬁc Entropy [J/(kg·K)]

HPT: Speciﬁc Enthalpy [J/kg]
P∗: Pressure [Pa], [bar]T∗: Temperature [K], [◦ C]

HPX: Speciﬁc Enthalpy of Mixture [J/kg]
P∗: Pressure [Pa], [bar]
X: Dryness Fraction [–]HTD: Speciﬁc Enthalpy of Saturated Liquid [J/kg]
T∗: Temperature [K], [◦ C]
HTDD: Speciﬁc Enthalpy of Saturated Vapor [J/kg]
T∗: Temperature [K], [◦ C]
HTX: Speciﬁc Enthalpy of Mixture [J/kg]
T∗: Temperature [K], [◦ C]
X: Dryness Fraction [–]IDENTF: CHARACTER TYPE FUNCTION
for Package Identiﬁcation (Length 20)
C: ‘A’=‘C’: ‘CH4’ Molecular Formula
S: ‘A’=‘S’: ‘METHANE’ Name of Substance
V: ‘A’=‘V’: ‘10.1’ Version Number
PMLT∗: Pressure on Melting Curve [Pa], [bar]T∗: Temperature [K], [◦ C]

90.68≤T≤190.555 [K]−182.47≤T≤−82.595 [◦C]
11.719×103 ≤P≤4.595×106 [Pa]0.11719≤P≤45.95 [bar]11.719×103 ≤P≤4.595×106 [Pa]0.11719≤P≤45.95 [bar]11.719×103 ≤P≤40×106 [Pa]SPT(P,TMLP(P))≤S≤
SPT(P,620K) [J/(kg·K)]
40×106 <P≤109 [Pa]SPT(P,TMLP(P))≤S≤
SPT(P,470K) [J/(kg·K)]
0.11719≤P≤400 [bar]SPT(P,TMLP(P))≤S≤
SPT(P,346.85◦ C) [J/(kg·K)]
400<P≤10000 [bar]SPT(P,TMLP(P))≤S≤
SPT(P,196.85◦ C) [J/(kg·K)]
11.719×103 ≤P≤40×106 [Pa]TMLP(P)≤T≤620 [K]
40×106 <P≤109 [Pa]TMLP(P)≤T≤470 [K]
0.11719≤P≤400 [bar]TMLP(P)≤T≤346.85 [◦ C]
400<P≤10000 [bar]TMLP(P)≤T≤196.85 [◦ C]
11.719×103 ≤P≤4.595×106 [Pa]0.11719≤P≤45.95 [bar]0≤X≤1.0 [–]90.68≤T≤190.555 [K]−182.47≤T≤−82.595 [◦C]
90.68≤T≤190.555 [K]−182.47≤T≤−82.595 [◦C]
90.68≤T≤190.555 [K]−182.47≤T≤−82.595 [◦C]
0≤X≤1.0 [–]one of ‘C’, ‘S’ and ‘V’

90.68≤T≤260 [K]−182.47≤T≤−13.15 [◦C]

230

P-PROPATH: Pure Substances and Mixtures with Fixed Composition
Table II–2.23–1

No.
81

Name of
Function
PRPT(P,T)

Methane Function (cont’d)

Function and Argument(s)PRPT: Prandtl Number [–]P∗: Pressure [Pa], [bar]T∗: Temperature [K], [◦ C]

Range of Argument(s)100×103 ≤P≤50×106 [Pa]300≤T≤423.15 [K]
1.0≤P≤500 [bar]26.85≤T≤150 [◦C]

87
88
99
30

PRTD(T)
PRTDD(T)PSBT(T)
PST(T)72
73
31

PSTD(T)
PSTDD(T)SIGP(P)

32

SIGT(T)

33

SPD(P)34

SPDD(P)35

SPT(P,T)36

SPX(P,X)

37

STD(T)38

STDD(T)

39

STX(T,X)

67
69

TLDP(P)
TMLP(P)

PST∗: Saturation Pressure [Pa], [bar]T∗: Temperature [K], [◦ C]

90.68≤T≤190.555 [K]−182.47≤T≤−82.595 [◦C]

SIGP: Surface Tension [N/m]P∗: Pressure [Pa], [bar]
SIGT: Surface Tension [N/m]T∗: Temperature [K], [◦ C]
SPD: Speciﬁc Entropy of Saturated Liquid[J/(kg·K)]
P∗: Pressure [Pa], [bar]SPDD: Speciﬁc Entropy of Saturated Vapor[J/(kg·K)]
P∗: Pressure [Pa], [bar]SPT: Speciﬁc Entropy [J/(kg·K)]
P∗: Pressure [Pa], [bar]T∗: Temperature [K], [◦ C]

11.719×103 ≤P≤4.595×106 [Pa]0.11719≤P≤45.95 [bar]90.68≤T≤190.555 [K]−182.47≤T≤−82.595 [◦C]
11.719×103 ≤P≤4.595×106 [Pa]0.11719≤P≤45.95 [bar]SPX: Speciﬁc Entropy of Mixture [J/(kg·K)]
P∗: Pressure [Pa], [bar]
X: Dryness Fraction [–]STD: Speciﬁc Entropy of Saturated Liquid[J/(kg·K)]
T∗: Temperature [K], [◦ C]
STDD: Speciﬁc Entropy of Saturated Vapor[J/(kg·K)]
T∗: Temperature [K], [◦ C]
STX: Speciﬁc Entropy of Mixture [J/(kg·K)]
T∗: Temperature [K], [◦ C]
X: Dryness Fraction [–]TMLP∗: Temperature on Melting Curve[K], [◦C]P∗: Pressure [Pa], [ bar]

11.719×103 ≤P≤4.595×106 [Pa]0.11719≤P≤45.95 [bar]11.719×103 ≤P≤40×106 [Pa]TMLP(P)≤T≤620 [K]
40×106 <P≤109 [Pa]TMLP(P)≤T≤470 [K]
0.11719≤P≤400 [bar]TMLP(P)≤T≤346.85 [◦ C]
400<P≤10000 [bar]TMLP(P)≤T≤196.85 [◦ C]
11.719×103 ≤P≤4.595×106 [Pa]0.11719≤P≤45.95 [bar]0≤X≤1.0 [–]90.68≤T≤190.555 [K]−182.47≤T≤−82.595 [◦C]
90.68≤T≤190.555 [K]−182.47≤T≤−82.595 [◦C]
90.68≤T≤190.555 [K]−182.47≤T≤−82.595 [◦C]
0≤X≤1.0 [–]11.719×103 ≤P≤109 [Pa]0.11719≤P≤10000 [bar]Methane(IUPAC Table)

231
Table II–2.23–1

No.
64

Name of
Function
TPH(P,H)

Methane Function (cont’d)

Function and Argument(s)TPH∗: Temperature [K], [◦C]P∗: Pressure [Pa], [bar]H: Speciﬁc Enthalpy [J/kg]

Range of Argument(s)11.719×103 ≤P≤40×106 [Pa]
HPT(P,TMLP(P))≤H≤
HPT(P,620K) [J/kg]
40×106 <P≤109 [Pa]
HPT(P,TMLP(P))≤H≤
HPT(P,470K) [J/kg]
0.11719≤P≤400 [bar]HPT(P,TMLP(P))≤H≤
HPT(P,346.85◦ C) [J/kg]
400<P≤10000 [bar]HPT(P,TMLP(P))≤H≤
HPT(P,196.85◦ C) [J/kg]

6H
65

TPH2(P,H)
TPS(P,S)TPS∗: Temperature [K], [◦ C]
P∗: Pressure [Pa], [bar]S: Speciﬁc Entropy [J/(kg·K)]

11.719×103 ≤P≤40×106 [Pa]SPT(P,TMLP(P))≤S≤
SPT(P,620K) [J/(kg·K)]
40×106 <P≤109 [Pa]SPT(P,TMLP(P))≤S≤
SPT(P,470K) [J/(kg·K)]
0.11719≤P≤400 [bar]SPT(P,TMLP(P))≤S≤
SPT(P,346.85◦ C) [J/(kg·K)]
400<P≤10000 [bar]SPT(P,TMLP(P))≤S≤
SPT(P,196.85◦ C) [J/(kg·K)]

6S
98

TPS2(P,S)TPSEUP(P)70

TPV(P,V)41

TRPL(‘A’)

100
40

TSBP(P)
TSP(P)

74
75
42

TSPD(P)TSPDD(P)UPD(P)43

UPDD(P)TPSEUP∗: Pseudo Boiling Point [K], [◦ C]
P∗: Pressure [Pa], [bar]TPV∗: Temperature [K], [◦C]P∗: Pressure [Pa], [bar]V: Speciﬁc Volume [m3 /kg]

TRPL∗: Properties at Triple PointP∗: ‘A’=‘P’: 11.719×103 [Pa],0.11719 [bar] PressureT∗: ‘A’=‘T’: 90.68 [K],−182.47 [◦C] Temperature

4.595×106 <P≤50×106 [Pa]45.95<P≤500 [bar]11.719×103 ≤P≤40×106 [Pa]VPT(P,TMLP(P))≤V≤
VPT(P,620K) [m3 /kg]
40×106 <P≤109 [Pa]VPT(P,TMLP(P))≤V≤
VPT(P,470K) [m3 /kg]
0.11719≤P≤400 [bar]VPT(P,TMLP(P))≤V≤
VPT(P,346.85◦ C) [m3 /kg]
400<P≤10000 [bar]VPT(P,TMLP(P))≤V≤
VPT(P,196.85◦ C) [m3 /kg]
one of ‘P’ and ‘T’

TSP∗: Saturation Temperature [K], [◦ C]
P∗: Pressure [Pa], [bar]11.719×103 ≤P≤4.595×106 [Pa]0.11719≤P≤45.95 [bar]UPD: Speciﬁc Internal Energy of Saturated
Liquid [J/kg]
P∗: Pressure [Pa], [bar]UPDD: Speciﬁc Internal Energy of Saturated
Vapor [J/kg]
P∗: Pressure [Pa], [bar]11.719×103 ≤P≤4.595×106 [Pa]0.11719≤P≤45.95 [bar]11.719×103 ≤P≤4.595×106 [Pa]0.11719≤P≤45.95 [bar]232

P-PROPATH: Pure Substances and Mixtures with Fixed Composition
Table II–2.23–1

No.
79
44

Name of
Function
UPS(P,S)
UPT(P,T)45

UPX(P,X)

46

UTD(T)

47

UTDD(T)

48

UTX(T,X)

49

VPD(P)50

VPDD(P)

80
51

VPS(P,S)
VPT(P,T)52

VPX(P,X)

53

VTD(T)54

VTDD(T)

55

VTX(T,X)

8E
8F
83

WPD(P)WPDD(P)
WPT(P,T)

Methane Function (cont’d)

Function and Argument(s)UPT: Speciﬁc Internal Energy [J/kg]
P∗: Pressure [Pa], [bar]T∗: Temperature [K], [◦ C]

UPX: Speciﬁc Internal Energy of Mixture [J/kg]
P∗: Pressure [Pa], [bar]
X: Dryness Fraction [–]UTD: Speciﬁc Internal Energy of Saturated
Liquid [J/kg]
T∗: Temperature [K], [◦ C]
UTDD: Speciﬁc Internal Energy of Saturated
Vapor [J/kg]
T∗: Temperature [K], [◦ C]
UTX: Speciﬁc Internal Energy of Mixture [J/kg]
T∗: Temperature [K], [◦ C]
X: Dryness Fraction [–]VPD: Speciﬁc Volume of Saturated Liquid [m3 /kg]P∗: Pressure [Pa], [bar]VPDD: Speciﬁc Volume of Saturated Vapor [m3 /kg]P∗: Pressure [Pa], [bar]VPT: Speciﬁc Volume [m3 /kg]P∗: Pressure [Pa], [bar]T∗: Temperature [K], [◦ C]

VPX: Speciﬁc Volume of Mixture [m3 /kg]P∗: Pressure [Pa], [bar]
X: Dryness Fraction [–]VTD: Speciﬁc Volume of Saturated Liquid [m3 /kg]
T∗: Temperature [K], [◦ C]
VTDD: Speciﬁc Volume of Saturated Vapor [m3 /kg]
T∗: Temperature [K], [◦ C]
VTX: Speciﬁc Volume of Mixture [m3 /kg]
T∗: Temperature [K], [◦ C]
X: Dryness Fraction [–]WPT: Velocity of Sound [m/s]P∗: Pressure [Pa], [bar]T∗: Temperature [K], [◦ C]

Range of Argument(s)11.719×103 ≤P≤40×106 [Pa]TMLP(P)≤T≤620 [K]
40×106 <P≤109 [Pa]TMLP(P)≤T≤470 [K]
0.11719≤P≤400 [bar]TMLP(P)≤T≤346.85 [◦ C]
400<P≤10000 [bar]TMLP(P)≤T≤196.85 [◦ C]
11.719×103 ≤P≤4.595×106 [Pa]0.11719≤P≤45.95 [bar]0≤X≤1.0 [–]90.68≤T≤190.555 [K]−182.47≤T≤−82.595 [◦C]
90.68≤T≤190.555 [K]−182.47≤T≤−82.595 [◦C]
90.68≤T≤190.555 [K]−182.47≤T≤−82.595 [◦C]
0≤X≤1.0 [–]11.719×103 ≤P≤4.595×106 [Pa]0.11719≤P≤45.95 [bar]11.719×103 ≤P≤4.595×106 [Pa]0.11719≤P≤45.95 [bar]11.719×103 ≤P≤40×106 [Pa]TMLP(P)≤T≤620 [K]
40×106 <P≤109 [Pa]TMLP(P)≤T≤470 [K]
0.11719≤P≤400 [bar]TMLP(P)≤T≤346.85 [◦ C]
400<P≤10000 [bar]TMLP(P)≤T≤196.85 [◦ C]
11.719×103 ≤P≤4.595×106 [Pa]0.11719≤P≤45.95 [bar]0≤X≤1.0 [–]90.68≤T≤190.555 [K]−182.47≤T≤−82.595 [◦C]
90.68≤T≤190.555 [K]−182.47≤T≤−82.595 [◦C]
90.68≤T≤190.555 [K]−182.47≤T≤−82.595 [◦C]
0≤X≤1.0 [–]11.719×103 ≤P≤40×106 [Pa]TMLP(P)≤T≤620 [K]
40×106 <P≤109 [Pa]TMLP(P)≤T≤470 [K]
0.11719≤P≤400 [bar]TMLP(P)≤T≤346.85 [◦ C]
400<P≤10000 [bar]TMLP(P)≤T≤196.85 [◦ C]

Methane(IUPAC Table)

233
Table II–2.23–1

No.
8G
8H
56

Name of
Function
WTD(T)WTDD(T)
XPH(P,H)57

XPS(P,S)58

XPU(P,U)59

XPV(P,V)60

XTH(T,H)

61

XTS(T,S)62

XTU(T,U)63

XTV(T,V)

Methane Function (cont’d)

Function and Argument(s)Range of Argument(s)XPH: Dryness Fraction [–]P∗: Pressure [Pa], [bar]H: Speciﬁc Enthalpy of Mixture [J/kg]
XPS: Dryness Fraction [–]P∗: Pressure [Pa], [bar]S: Speciﬁc Entropy of Mixture [J/(kg·K)]
XPU: Dryness Fraction [–]P∗: Pressure [Pa], [bar]U: Speciﬁc Internal Energy of Mixture [J/kg]
XPV: Dryness Fraction [–]P∗: Pressure [Pa], [bar]V: Speciﬁc Volume of Mixture [m3 /kg]
XTH: Dryness Fraction [–]T∗: Temperature [K], [◦C]
H: Speciﬁc Enthalpy of Mixture [J/kg]
XTS: Dryness Fraction [–]T∗: Temperature [K], [◦C]
S: Speciﬁc Entropy of Mixture [J/(kg·K)]
XTU: Dryness Fraction [–]T∗: Temperature [K], [◦C]
U: Speciﬁc Internal Energy of Mixture [J/kg]
XTV: Dryness Fraction [–]T∗: Temperature [K], [◦C]
V: Speciﬁc Volume of Mixture [m3 /kg]

11.719×103 ≤P≤4.595×106 [Pa]0.11719≤P≤45.95 [bar]HPD(P)≤H≤HPDD(P) [J/kg]
11.719×103 ≤P≤4.595×106 [Pa]0.11719≤P≤45.95 [bar]SPD(P)≤S≤SPDD(P) [J/(kg·K)]
11.719×103 ≤P≤4.595×106 [Pa]0.11719≤P≤45.95 [bar]UPD(P)≤U≤UPDD(P) [J/kg]
11.719×103 ≤P≤4.595×106 [Pa]0.11719≤P≤45.95 [bar]VPD(P)≤V≤VPDD(P) [m3 /kg]
90.68≤T≤190.555 [K]−182.47≤T≤−82.595 [◦ C]
HTD(T)≤H≤HTDD(T) [J/kg]
90.68≤T≤190.555 [K]−182.47≤T≤−82.595 [◦ C]
STD(T)≤S≤STDD(T) [J/(kg·K)]
90.68≤T≤190.555 [K]−182.47≤T≤−82.595 [◦ C]
UTD(T)≤U≤UTDD(T) [J/kg]
90.68≤T≤190.555 [K]−182.47≤T≤−82.595 [◦ C]
VTD(T)≤V≤VTDD(T) [m3 /kg]