Stoichiometric Combustion Calculator for Alkane, Alkene and Alkyne fuels

Stoichiometric combustion offers an easy way to understand combustion concepts. When fuel and air mix they produce products as co2, co, oh, h2o, no, n2o and many more. In stoichiometric combustion we make a simple assumption that the by products are only co2, h2o and n2. For a generic alkane fuel the combustion process will following the below equation

Here

n = Number of moles of C

ar = Stoichiometric co-efficient

a = Number of moles of Carbon-di-oxide

b = Number of moles of water

c = Number of moles of nitrogen

'ar' is calculated for various number of moles.

Fuels were varied from alkalenes, alkenes and alkalynes.

We could observe a linear increase of Stoichiometric co-efficient with increase in carbon moles.

Code was developed to calculate 'ar' co-efficient in GNU Octave.

Graph was plotted for a range of number of moles of carbon for all the three types of fuels.

clear all

close all
clc

#for alkanes

for i = 1:10
  n=i
  c= n;
  h = (2*n)+2;
  a = [c,0,-1,0,0;h,0,0,-2,0;0,2,-2,-1,0;0,7.52,0,-1,-2;0,0,0,0,1];

  b= [0;0;0;0;1];
  c= inv(a) *b ;
  d = c/min(c)
  alka(i) = [d(2)]
   
end

#for alkenes
#c2h4
for i = 2:11
  n=i
  c= n;
  h = (2*n);
  a = [c,0,-1,0,0;h,0,0,-2,0;0,2,-2,-1,0;0,7.52,0,-1,-2;0,0,0,0,1];

  b= [0;0;0;0;1];
  c= inv(a) *b ;
  e= c/min(c)
  alke(i-1) = [e(2)]
   
end


#for alkynes

for i = 2:11
  n=i
  c= n;
  h = (n);
  a = [c,0,-1,0,0;h,0,0,-2,0;0,2,-2,-1,0;0,7.52,0,-1,-2;0,0,0,0,1];

  b= [0;0;0;0;1];
  c= inv(a) *b ;
  f= c/min(c)
  alky(i-1) = [f(2)]
   
end


xaxis = linspace(1,10,10)
#figure (1)
plot(xaxis,alka,'r--')
#legend('s')
hold on

xaxis2 = linspace(2,11,10)
#figure (2)
plot(xaxis2,alke, 'b--')


xaxis3 = linspace(2,11,10)
plot(xaxis3,alky)
hold off
legend( 'Alkanes','Alkenes','Alkynes')
xlabel('moles of carbon')
ylabel('stoichiometric co-efficient "ar"')