LHV of Producer Gas in Co-Gasification of Two Biomasses (Mathematica vs. Aspen-Plus)​
​Asma Hammami, Housam Binous, Hatem Dhaouadi and Ahmed Bellagi

We consider olive pomace + grape pomace gasification (or biomass co-gasification) in the presence of oxygen only.

We investigate (1) the effect of temperature and (2) Equivalence Ratio (ER) on the Lower Heating Value (LHV) of the producer gas.
​
Based on proximate and ultimate analyses, given in Aspen-Plus, olive pomace is modeled as a pseudo-compound whose formula is
C
1
H
1.53015
O
0.501421
while grape pomace is modeled as
C
1
H
1.30934
O
0.438956
.
​
LHV calculated using Mathematica agree closely with their counterpart given by Aspen-Plus.
In[]:=
In[]:=
sol[{x_,ER_}]:=Quiet@FindMinimum[{Re[Gtot[x,P]],{n[7]<1/1000000,n[1]>0,n[2]>0,n[3]>0,n[4]>0,n[5]>0,n[6]>0,n[7]>0,n[8]>0,n[9]>0,n[10]>0},n[1]+n[5]+n[4]+n[10]1+1,​​4n[1]+2n[2]+2n[3]1.53015+1.30934,​​n[3]+n[4]+2n[5]+n[6]+2n[7]+2n[9]0.501421+0.438956+2ER2.2397,n[6]+n[7]+2n[8]0.0},Table[{n[j],0.07},{j,1,10}],MaxIterations10000,AccuracyGoal5];(*xistemperatureandERisequivalenceratio*)​​
Temperature effect on LHV for ER=0.446
In[]:=
P=1;
In[]:=
ER=1/2.2397(*equivalenceratio*)
Out[]=
0.446488
In[]:=
LHV=<|"H2"->242,"CO"->283.0,"CH4"->802.0|>;
In[]:=
tbl=Table[{T,y[2]*LHV["H2"]+y[4]*LHV["CO"]+y[1]*LHV["CH4"]/.sol[{T,ER}][[2]]},{T,700,1200,20}]
Out[]=
{{700,77.6723},{720,81.1962},{740,85.1608},{760,89.7363},{780,95.1087},{800,101.468},{820,108.992},{840,117.822},{860,128.034},{880,139.607},{900,152.391},{920,166.091},{940,180.267},{960,193.775},{980,193.162},{1000,192.839},{1020,192.713},{1040,192.703},{1060,192.757},{1080,192.846},{1100,192.951},{1120,193.064},{1140,193.18},{1160,193.295},{1180,193.408},{1200,193.518}}
In[]:=
p1=ListPlot[tbl,Frame->True,GridLines->Automatic,AspectRatio->1,Joined->True];
In[]:=
tbl2={{700,77.9444699},{750,87.3949567},{800,101.07839},{850,121.732832},{900,150.569325},{950,184.821545},{1000,192.577999},{1050,192.448577},{1100,192.672723},{1150,192.959634},{1200,193.241435}};
In[]:=
p2=ListPlot[tbl2,PlotMarkers->"OpenMarkers",PlotStyle->Red];(*Aspenresultsarerepresentedusingredopenmarkers*)
In[]:=
Show[p1,p2,FrameLabel->{Style["Temperature (K)",16],Style["LHV in MJ/kmol",16]}]
Out[]=
ER effect on LHV for T=800K
In[]:=
P=1;
In[]:=
ER=.(*equivalenceratio*)
In[]:=
LHV=<|"H2"->242,"CO"->283.0,"CH4"->802.0|>;
In[]:=
tbl=Table[{ER,y[2]*LHV["H2"]+y[4]*LHV["CO"]+y[1]*LHV["CH4"]/.sol[{800,ER}][[2]]},{ER,0.01,0.75,0.025}]
Out[]=
{{0.01,215.416},{0.035,202.01},{0.06,190.151},{0.085,179.6},{0.11,170.167},{0.135,161.692},{0.16,154.046},{0.185,147.12},{0.21,140.822},{0.235,135.077},{0.26,129.818},{0.285,124.99},{0.31,120.545},{0.335,116.442},{0.36,112.645},{0.385,109.124},{0.41,105.85},{0.435,102.8},{0.46,99.9538},{0.485,97.2919},{0.51,94.7982},{0.535,92.4582},{0.56,90.2587},{0.585,88.1883},{0.61,86.2364},{0.635,84.3937},{0.66,82.6517},{0.685,81.0029},{0.71,79.4403},{0.735,77.9575}}
In[]:=
p1=ListPlot[tbl,Frame->True,GridLines->Automatic,AspectRatio->1,Joined->True];
In[]:=
tbl2={{0.05,207.838366},{0.15,186.423541},{0.25,169.000076},{0.35,154.60348},{0.45,142.548195},{0.55,132.335232},{0.65,123.593859},{0.75,116.043619},{0.85,109.468944},{0.95,103.701766},{1,101.07839},{1.05,98.6093712},{1.15,94.0857436},{1.25,90.0453074},{1.35,86.4183224},{1.45,83.1474556},{1.5,81.6303924}};
In[]:=
tbl2=Table[{tbl2[[i]][[1]]/2.2397,tbl2[[i]][[2]]},{i,1,Length@tbl2,2}]
Out[]=
{{0.0223244,207.838},{0.111622,169.},{0.20092,142.548},{0.290217,123.594},{0.379515,109.469},{0.446488,101.078},{0.513462,94.0857},{0.602759,86.4183},{0.669733,81.6304}}
In[]:=
p2=ListPlot[tbl2,PlotMarkers->"OpenMarkers",PlotStyle->Red];(*Aspenresultsarerepresentedusingredopenmarkers*)
In[]:=
Show[p1,p2,FrameLabel->{Style["ER",16],Style["LHV in MJ/kmol",16]},PlotRange->All]
Out[]=