Lee-Kesler Generalized Correlations for Gases​
​Authors: Housam Binous and Ahmed Bellagi

Using a modified version of the Benedict–Webb–Rubin equation of state, Lee and Kesler [1, 2] generated several tables to estimate the following properties at a reduced pressure and temperature .​1.
0
Z
and
1
Z
or the compressibility factor
Z=
0
Z
+ω
1
Z
,​2.
0
R
H
R
T
c
and
1
R
H
R
T
c
or the residual enthalpy
R
H
=R
T
c
0
R
H
R
T
c
+ω
1
R
H
R
T
c
,​3.
0
R
S
R
and
1
R
S
R
or the residual entropy
R
S
=R
0
R
S
R
+ω
1
R
S
R
, and​4.
0
ϕ
and
1
ϕ
or the fugacity coefficient
ϕ=
ω
0
ϕ

1
ϕ

.​In the preceding expressions,
ω
and
T
c
are the acentric factor and critical temperature of methane, respectively (i.e.,
ω=0.012
and
T
c
=190.6K
). These two parameters must be modified in case you select another alkane. ​You can also choose any other value for
T
r
and
P
r
. Here, we set
P
r
=0.40
and
T
r
=0.65
for illustration purposes . ​Here, we display all of the cited thermodynamic properties in the form of a table.
References:​
[1] J. M. Smith, H. C. Van Ness, M. M. Abbott and M. T. Swihart, Introduction to Chemical Engineering Thermodynamics, 9th ed., Boston: McGraw-Hill, 2022.
[2] B. I. Lee and M. G. Kesler, "A Generalized Thermodynamic Correlation Based on Three-Parameter Corresponding States," AlChE Journal, 21(3), 1975 pp. 510–527. doi:10.1002/aic.690210313.
Reduced temperature and pressure (user can change these values if needed)
In[]:=
Tre=0.65;​​Pre=0.40;
Acentric factor and critical temperature of Methane (user can select a different alkane if needed)
In[]:=
w=0.012;​​Tc=190.6;
Universal gas constant
In[]:=
R=8.314;
Following Ref. 2, we compute:​1.
0
Z
2.
0
R
H
R
T
c
​3.
0
R
S
R
4.
0
ϕ
Ba0=b10-b20/Tre-b30/Tre^2-b40/Tre^3;​​Ca0=c10-c20/Tre+c30/Tre^3;​​Da0=d10+d20/Tre;​​Ea0=c40/2/Tre^3/gamma0(beta0+1-(beta0+1+gamma0/Vre^2)Exp[-gamma0/Vre^2]);​​​​Vre=ZTre/Pre;​​​​eq0=Z1+Ba0/Vre+Ca0/Vre^2+Da0/Vre^5+c40/Tre^3/Vre^2(beta0+gamma0/Vre^2)Exp[-gamma0/Vre^2];​​​​b10=0.1181193;​​b20=0.265728;​​b30=0.154790;​​b40=0.030323;​​​​c10=0.0236744;​​c20=0.0186984;​​c30=0.0;​​c40=0.042724;​​​​d10=0.15548810^-4;​​d20=0.62368910^-4;​​​​beta0=0.65392;​​gamma0=0.060167;​​​​Z0=Z/.FindRoot[eq0,{Z,0.01,0.95}];​​​​H0overRTc=Tre(Z0-1-(b20+2b30/Tre+3b40/Tre^2)/Tre/Vre-(c20-3c30/Tre^2)/2/Tre/Vre^2+d20/5/Tre/Vre^5+3Ea0)/.ZZ0;​​​​phi0=Exp[Z0-1-Log[Z0]+Ba0/Vre+Ca0/2/Vre^2+Da0/5/Vre^5+Ea0/.ZZ0];​​​​S0overR=Log[Z0]-(b10+b30/Tre^2+2b40/Tre^3)/Vre-(c10-2c30/Tre^3)/2/Vre^2-d10/5/Vre^5+2Ea0/.ZZ0;
Following Ref. 2, we compute:​1.
1
Z
2.
1
R
H
R
T
c
​3.
1
R
S
R
4.
1
ϕ
Ba=b1-b2/Tre-b3/Tre^2-b4/Tre^3;​​Ca=c1-c2/Tre+c3/Tre^3;​​Da=d1+d2/Tre;​​Ea=c4/2/Tre^3/gamma(beta+1-(beta+1+gamma/Vre^2)Exp[-gamma/Vre^2]);​​​​b1=0.2026579;​​b2=0.331511;​​b3=0.027655;​​b4=0.203488;​​​​c1=0.0313385;​​c2=0.0503618;​​c3=0.016901;​​c4=0.041577;​​​​d1=0.4873610^-4;​​d2=0.074033610^-4;​​​​beta=1.226;​​gamma=0.03754;​​​​wr=0.3978;​​​​eq1=Z1+Ba/Vre+Ca/Vre^2+Da/Vre^5+c4/Tre^3/Vre^2(beta+gamma/Vre^2)Exp[-gamma/Vre^2];​​Zc=Z/.FindRoot[eq1,{Z,0.01,0.95}];​​​​Z1=(Zc-Z0)/wr;​​​​H1overRTc=((Tre(Z-1-(b2+2b3/Tre+3b4/Tre^2)/Tre/Vre-(c2-3c3/Tre^2)/2/Tre/Vre^2+d2/5/Tre/Vre^5+3Ea)/.ZZc)-H0overRTc)/wr;​​​​phi1=Exp[((Z-1-Log[Z]+Ba/Vre+Ca/2/Vre^2+Da/5/Vre^5+Ea/.ZZc)-Log[phi0])/wr];​​​​S1overR=((Log[Z]-(b1+b3/Tre^2+2b4/Tre^3)/Vre-(c1-2c3/Tre^3)/2/Vre^2-d1/5/Vre^5+2Ea/.ZZc)-S0overR)/wr;
Generating a table with the thermodynamic properties of methane at the reduced pressure and temperature (
P
r
=0.40
and
T
r
=0.65
):
​
​1- compressibility factor
2- residual enthalpy
3- residual entropy
4- fugacity coefficient​
​
One can easily check our results against the values reported in the corresponding Tables of Appendix D of Ref. 1.
​
In[]:=
GraphicsGrid[{{​​Text@Style[Grid[{{"property","value"},​​{​​Row[{Superscript[Style["Z",Italic],"0"]}],​​NumberForm[Z0,{5,4}]​​},{​​Row[{Superscript[Style["Z",Italic],"1"]}],​​NumberForm[Z1,{5,4}]​​},{​​Row[{Style["Z",Italic]}],​​NumberForm[Z0+wZ1,{5,4}]​​},{​​Row[{Superscript[Row[{"(",Style[Superscript["H","R"],Italic],")"}],"0"],"/",Style[Subscript["RT","c"],Italic]}],​​NumberForm[H0overRTc,{5,4}]​​},{​​Row[{Superscript[Row[{"(",Style[Superscript["H","R"],Italic],")"}],"1"],"/",Style[Subscript["RT","c"],Italic]}],​​NumberForm[H1overRTc,{5,4}]​​},{​​Row[{Style[Superscript["H","R"],Italic]," (J/mol)"}],​​NumberForm[RTc(H0overRTc+wH1overRTc),{5,2}]​​}}​​,FrameAll,Background{None,{Lighter[Blend[{Blue,Green}],.3],{Lighter[Blend[{Blue,Darker@Green}],.8],Lighter[Green,.9]}}},ItemSize{8.4,2.0},FrameDarker[Gray,.6],ItemStyle14,Spacings{Automatic,.8}],16],​​​​Graphics[{​​Text@Style[Grid[{{"property","value"},​​{​​Row[{Superscript[Row[{"(",Style[Superscript["S","R"],Italic],")"}],"0"],"/"Style["R",Italic]}],​​NumberForm[S0overR,{5,4}]​​},{​​Row[{Superscript[Row[{"(",Style[Superscript["S","R"],Italic],")"}],"1"],"/"Style["R",Italic]}],​​NumberForm[S1overR,{5,4}]​​},{​​Row[{Style[Superscript["S","R"],Italic]," (J/mol.K)"}],​​NumberForm[R(S0overR+wS1overR),{5,4}]​​},{​​Row[{Superscript["ϕ","0"]}],​​NumberForm[phi0,{5,4}]​​},{​​Row[{Superscript["ϕ","1"]}],​​NumberForm[phi1,{5,4}]​​},{​​Row[{"ϕ"}],​​NumberForm[phi0phi1^w,{5,4}]​​}}​​,FrameAll,Background{None,{Lighter[Blend[{Blue,Red}],.3],{Lighter[Blend[{Blue,Darker@Red}],.8],Lighter[Red,.9]}}},ItemSize{8.4,2.0},FrameDarker[Gray,.6],ItemStyle14,Spacings{Automatic,.8}],16]}]​​}},ImageSize600{1.1,0.7}]