Production of SynGas using Coal-Steam reactions​
​Authors: Housam Binous, Raoudha Garma and Ahmed Bellagi

References :​[1] S. I. Sandler, Chemical, Biochemical and Engineering Thermodynamics, 5th Edition, NY: Wiley, 2017.​[2] Tilouche, R., Garma, R., Binous, H. et al. Valorization of Tunisian olive pomace by steam gasification: thermodynamic study using MATHEMATICA© and ASPEN-PLUS®. Biomass Conv. Bioref. (2023). https://doi.org/10.1007/s13399-023-04167-z​​[3] https://webbook.nist.gov/chemistry/
We compute the equilibrium mole fractions of H2O, CO, CO2, H2, and CH4 in the steam-carbon system at a total pressure of 1 bar and over the temperature range of 600 to 1600 K.​Reaction taking place at 1 Bar (Ref. 2) :​​
​​The set of independent reactions is given below:​ C + 2 H2O = CO2 + 2 H2 (rxn 1) C + H20 = CO + H2 (rxn 2) C + 2 H2 = CH4 (rxn 3)
In[]:=
Off[General::"spell1"]
Plot of equilibrium constant versus temperature obtained using NIST Chemistry WebBook (Ref. 2 and 3)
In[]:=
Gwater[T_]:=Modulea,b,c,d,e,f,g,h,θ=
T
1000
,ΔHo=-241.826,HH,SS,If[500≤T≤1700,{a,b,c,d,e,f,g,h}={30.09200,6.832514,6.793435,-2.534480,0.082139,-250.8810,223.3967,-241.8264},If[1700<T≤6000,{a,b,c,d,e,f,g,h}={41.96426,8.622053,-1.499781,0.098119,-11.15764,-272.1797,219.7809,-241.8264}]];HH=aθ+
b
2
2
θ
+
c
3
3
θ
+
d
4
4
θ
-
e
θ
+f-h+ΔHo;SS=
aLog[θ]+bθ+
c
2
2
θ
+
d
3
3
θ
-
e
2
2
θ
+g
1000
;HH-TSS
In[]:=
Gh2[T_]:=Modulea,b,c,d,e,f,g,h,θ=
T
1000
,ΔHo=0.0,HH,SS,If[298<T≤1000,{a,b,c,d,e,f,g,h}={33.066178,-11.363417,11.432816,-2.772874,-0.158558,-9.980797,172.707974,0.0},If[1000≤T≤2500,{a,b,c,d,e,f,g,h}={18.563083,12.257357,-2.859786,0.268238,1.977990,-1.147438,156.288133,0.0},If[2500<T≤6000,{a,b,c,d,e,f,g,h}={43.413560,-4.293079,1.272428,-0.096876,-20.533862,-38.515158,162.081354,0.0}]]];HH=aθ+
b
2
2
θ
+
c
3
3
θ
+
d
4
4
θ
-
e
θ
+f-h+ΔHo;SS=
aLog[θ]+bθ+
c
2
2
θ
+
d
3
3
θ
-
e
2
2
θ
+g
1000
;HH-TSS
In[]:=
Gco[T_]:=Modulea,b,c,d,e,f,g,h,θ=
T
1000
,ΔHo=-110.53,HH,SS,If[298≤T≤1300,{a,b,c,d,e,f,g,h}={25.56759,6.096130,4.054656,-2.671301,0.131021,-118.0089,227.3665,-110.5271},​​If[1300<T≤6000,{a,b,c,d,e,f,g,h}={35.15070,1.300095,-0.205921,0.013550,-3.282780,-127.8375,231.7120,-110.5271}]];HH=aθ+
b
2
2
θ
+
c
3
3
θ
+
d
4
4
θ
-
e
θ
+f-h+ΔHo;SS=
aLog[θ]+bθ+
c
2
2
θ
+
d
3
3
θ
-
e
2
2
θ
+g
1000
;HH-TSS
In[]:=
Gco2[T_]:=Modulea,b,c,d,e,f,g,h,θ=
T
1000
,ΔHo=-393.51,HH,SS,If[298≤T≤1200,{a,b,c,d,e,f,g,h}={24.99735,55.18696,-33.69137,7.948387,-0.136638,-403.6075,228.2431,-393.5224},​​If[1200<T≤6000,{a,b,c,d,e,f,g,h}={58.16639,2.720074,-0.492289,0.038844,-6.447293,-425.9186,263.6125,-393.5224​​}]];HH=aθ+
b
2
2
θ
+
c
3
3
θ
+
d
4
4
θ
-
e
θ
+f-h+ΔHo;SS=
aLog[θ]+bθ+
c
2
2
θ
+
d
3
3
θ
-
e
2
2
θ
+g
1000
;HH-TSS
In[]:=
Gch4[T_]:=Modulea,b,c,d,e,f,g,h,θ=
T
1000
,ΔHo=-74.87,HH,SS,If[298≤T≤1300,{a,b,c,d,e,f,g,h}={-0.703029,108.4773,-42.52157,5.862788,0.678565,-76.84376,158.7163,-74.87310},​​If[1300<T≤6000,{a,b,c,d,e,f,g,h}={85.81217,11.26467,-2.114146,0.138190,-26.42221,-153.5327,224.4143,​​-74.87310}]];HH=aθ+
b
2
2
θ
+
c
3
3
θ
+
d
4
4
θ
-
e
θ
+f-h+ΔHo;SS=
aLog[θ]+bθ+
c
2
2
θ
+
d
3
3
θ
-
e
2
2
θ
+g
1000
;HH-TSS
In[]:=
Tc=Join[{298.15},Table[i,{i,300,2000,100}]];​​
In[]:=
Gs=Interpolation[Transpose[{Tc,{-1.712,-1.722,-2.449,-3.473,-4.789,-6.386,-8.248,-10.358,-12.700,-15.257,-18.016,-20.965,-24.091,-27.385,-30.837,-34.439,-38.183,-42.061,-46.069}}]];​​
In[]:=
rxn1[T_]:=Gco2[T]+2Gh2[T]-2Gwater[T]-Gs[T]
In[]:=
rxn2[T_]:=Gco[T]+Gh2[T]-Gs[T]-Gwater[T]
In[]:=
rxn3[T_]:=Gch4[T]-2Gh2[T]-Gs[T]
In[]:=
R=8.314;
In[]:=
K1[T_]:=Exp[-10^3rxn1[T]/R/T]
In[]:=
K2[T_]:=Exp[-10^3rxn2[T]/R/T]
In[]:=
K3[T_]:=Exp[-10^3rxn3[T]/R/T]
In[]:=
p1=Plot[{Log10[K1[T]],Log10[K2[T]],Log10[K3[T]]},{T,600,1600},FrameTrue,​​GridLinesAutomatic,AspectRatio1.3,PlotStyleThick,PlotRangeAll];
Comparison between our data (colord lines) and the digitized data (black squares) from Fig. 13.3 - 1 (Ref. 1)​​
In[]:=
DATASANDLERkEQ={{650.,1.51046567998152},{650.,-2.23905174627189},{650.,-3.10195438683431},{700.,0.996833155837218},{700.,-1.69460127067892},{700.,-2.34177825110075},{750.,0.54483653459023},{750.,-1.20151404750039},{750.,-1.68432862019604},{800.,0.154475816240561},{800.,-0.749517426253413},{800.,-1.13987814460308},{850.,-0.194794300177564},{850.,-0.348884057420856},{850.,-0.646790921424552},{900.,0.0106587094801562},{900.,-0.215339601143337},{900.,-0.502973814664147},{950.,0.308565573483852},{950.,0.154475816240561},{950.,-0.780335377702069},{1000.,0.555109185073117},{1000.,0.483200631692914},{1000.,-1.02687898929133},{1050.,0.83247074811104},{1050.,-1.23233199894905},{1100.,1.12010496163185},{1100.,-1.43778500860677},{1150.,1.39746652466977},{1150.,1.27419471887514},{1150.,-1.62269271729872},{1200.,1.66455543722481},{1200.,1.45910242756709},{1200.,-1.80760042599067},{1250.,1.8905537478483},{1250.,1.64401013625903},{1250.,-1.96169018323396},{1300.,2.11655205847179},{1300.,1.79809989350233},{1300.,-2.11577994047725},{1350.,2.30145976716374},{1350.,1.95218965074562},{1350.,-2.24932439675477},{1400.,2.48636747585569},{1400.,2.09600675750602},{1400.,-2.38286885303229},{1450.,-2.48559535786115},{1500.,2.81509229130805},{1500.,-2.5985945131729},{1550.,2.94863674758556},{1549.99999999999,2.48636747585569},{1550.,-2.70132101800176},{1600.,3.},{1599.99999999999,2.58909398068455},{620.679137491754,-3.75488837381005},{612.321546366172,-2.64595525269458},{1470.28486011171,2.30673146170093},{1449.84779622244,2.66651940522515},{605.440604215711,1.9774024292086}};