

Formulae for the burning of various fuels 

The following formulae assume complete burning of the fuel in oxygen. 

Although this is an assumption, the formulae give a good estimate of 

the amounts of exhaust gases produced, but do not include other 

noxious products.  


 
Hydrogen 

balanced equation   2 H₂ + O₂ > 2 H₂O     
molecular weights   2*2 + 2*16 > 2(2+16)     
   4 + 32 > 36     
weights normalised to hydrogen   1 + 8 > 9  weights in any consistent units, eg kg, lbf or tons   
Summary  One ton of hydrogen burns in 8 tons of oxygen to give 9 tons of water (vapour).   

 

 
Kerosene 

basic equation not balanced  C₁₂H₂₆ + O₂ > CO₂ + H₂O    
balanced equation  2C₁₂H₂₆ + 37O₂ > 24CO₂ + 26H₂O     
comprising  (2*12) C + (2*26) H + (2*37) O > 24 C + (2x26) H + (2x24 + 26)O    
or  24 C + 52 H + 74 O > 24 C + 52 H + 74 O    
molecular weights left side  2*12*12 + 2*26*1 + 2*37*16 = 1524     
molecular weights right side  24*12 + 24*2*16 + 26*2*1 + 26*16 = 1524    
molecular weights of each chemical 
in balanced equation above     
kerosene 2*(12*12 + 26*1) = 340   
oxygen   37*(2*16) = 1184   
carbon dioxide 24*(12+2*16) = 1056 
water 26*(2*1 + 16) = 468 
totals    340 + 1184 = 1524   and  1056 + 468 = 1524   
weights normalised to kerosene 340/340=1  1184/340=3.482  1056/340=3.106  468/340=1.376   
Summary One ton of kerosene burns in 3.48 tons of oxygen to give 3.11 tons of CO₂ and 1.38 tons of water (vapour).   

 



Note that SAF (Sustainable or Synthetic Aircraft Fuel) is the same chemically as kerosene, so has the same emissions. 
In fact half of it is fossil derived kerosene, the other half is derived from specially grown plant matter. 

 

 
Methane (fossil gas)  

balanced equation   2C₂H₆ + 7O₂ > 4CO₂ + 6H₂O     
molecular weights left side   2*2*12 + 2*6 +7*2*16 = 284     
 right side   4*12 + 4*2*16 + 6*2 + 6*16 = 284     
 methane   2*2*12  2*16 = 60     
 oxygen   7*2*16 = 224     
 carbon dioxide   4*12 +4*2*16 = 176     
 water   6*2 + 6*16 = 108     
weights normalised to methane   60/60 = 1    224/60 = 3.733     176/60 = 2.933    108/60 = 1.800    
Summary  One ton of methane burns in 3.73 tons of oxygen to give 2.93 tons of CO₂ and 1.8 tons of water (vapour).   

 

 
Methyl alcohol (Methanol)  

balanced equation   2CH₃OH + 3O₂ > 2CO₂ + 4H₂O     
comprising   2 C  8 H   8 O  >   2 C   8 H   8 O     
molecular weights left side   2(12 + 3 + 16 + 1) + 382*16 = 160     
right side   2(12 + 2*16) + 4(2 + 16) = 160     
methanol   2(12 + 3 + 16 + 1) = 64     
oxygen   3*2*16 = 96     
carbon dioxide   2(12 + 2*16) = 88     
water   4(2 + 16) = 72     
weights normalised to methanol   64/64 = 1    96/64 = 1.500    88/64 = 1.375    72/64 = 1.125  weights in any consistent units, eg kg, lbf or tons   
Summary  One ton of methanol burns in 1.5 tons of oxygen to give 1 and 3/8ths tons of carbon dioxide and 1 and 1/8th tons of water (vapour).   

 




 
Octane (petrol)  

balanced equation   2C₈H₁₈ + 25O₂ > 16CO₂ + 18H₂O    
 comprising   16 C   36 H   25 O₂   >  16 C   16 O₂   36 H    9 O₂   
molecular weights left side   16*12 + 36*1 + 25*2*16 = 1028   
 right side   16*12 + 16*2*16 + 36*1 + 9*2*16 = 1028   
 octane   192 + 36 = 228   
 oxygen   25*2*16 = 800   
 carbon dioxide   192 + 512 = 704    
 water   36 + 288 = 324    
weights normalised to octane   228/228 = 1    800/228 = 3.509     704/228 = 3.09    324/228 = 1.42    
Summary  One ton of octane burns in 3.5 tons of oxygen to give 3.1 tons of CO₂ and 1.42 tons of water (vapour).   

 

 
Ethanol (ethyl alcohol) C2H6O or CH3 CH2 OH  

balanced equation   2C₂H₆O + 3O₂ > 2CO₂ + 3H₂O    
 comprising   2C 6H 7O > 2C 6H 7O
molecular weights left side   2*12 + 6*1 + 16 + 3*2*16 = 142   
 right side   2*12 + 2*2*16 + 3*2*1 + 3*16 = 142   
 ethanol left side   24 + 6 + 16 = 46   
 oxygen left side   3*2*16 = 96   
 carbon dioxide right side   2* (12 + 2*16) = 88    
 water right side   3* (2 + 16) = 54    
weights normalised to ethanol   46/46  = 1    96/46 = 2.087     88/46 = 1.913    54/46 = 1.174    
Summary  One ton of ethanol burns in 2.1 tons of oxygen to give 1.9 tons of CO₂ and 1.2 tons of water (vapour), approximately.   

 

 
So as an interim measure, until I can get all of this typed up, 
 
I have put the .pdf file that I am using as content for the website.  
 
 Some formulae and general info about burning fuels, and trees offset.

Hydrogen
balanced equation	2 H₂ + O₂ > 2 H₂O
molecular weights	22 + 216 > 2(2+16)
	4 + 32 > 36
weights normalised to hydrogen	1 + 8 > 9	weights in any consistent units, eg kg, lbf or tons
Summary	One ton of hydrogen burns in 8 tons of oxygen to give 9 tons of water (vapour).

Kerosene
basic equation not balanced	C₁₂H₂₆ + O₂ > CO₂ + H₂O
balanced equation	2C₁₂H₂₆ + 37O₂ > 24CO₂ + 26H₂O
comprising	(212) C + (226) H + (2*37) O > 24 C + (2x26) H + (2x24 + 26)O
or	24 C + 52 H + 74 O > 24 C + 52 H + 74 O
molecular weights left side	21212 + 2261 + 23716 = 1524
molecular weights right side	2412 + 24216 + 2621 + 2616 = 1524
molecular weights of each chemical in balanced equation above
kerosene	2(1212 + 26*1) = 340
oxygen	37(216) = 1184
carbon dioxide	24(12+216) = 1056
water	26(21 + 16) = 468
totals	340 + 1184 = 1524 and 1056 + 468 = 1524
weights normalised to kerosene	340/340=1 1184/340=3.482 1056/340=3.106 468/340=1.376
Summary	One ton of kerosene burns in 3.48 tons of oxygen to give 3.11 tons of CO₂ and 1.38 tons of water (vapour).

Methane (fossil gas)
balanced equation	2C₂H₆ + 7O₂ > 4CO₂ + 6H₂O
molecular weights left side	2212 + 26 +72*16 = 284
right side	412 + 4216 + 62 + 6*16 = 284
methane	2212 2*16 = 60
oxygen	7216 = 224
carbon dioxide	412 +42*16 = 176
water	62 + 616 = 108
weights normalised to methane	60/60 = 1 224/60 = 3.733 176/60 = 2.933 108/60 = 1.800
Summary	One ton of methane burns in 3.73 tons of oxygen to give 2.93 tons of CO₂ and 1.8 tons of water (vapour).

Methyl alcohol (Methanol)
balanced equation	2CH₃OH + 3O₂ > 2CO₂ + 4H₂O
comprising	2 C 8 H 8 O > 2 C 8 H 8 O
molecular weights left side	2(12 + 3 + 16 + 1) + 382*16 = 160
right side	2(12 + 2*16) + 4(2 + 16) = 160
methanol	2(12 + 3 + 16 + 1) = 64
oxygen	3216 = 96
carbon dioxide	2(12 + 2*16) = 88
water	4(2 + 16) = 72
weights normalised to methanol	64/64 = 1 96/64 = 1.500 88/64 = 1.375 72/64 = 1.125	weights in any consistent units, eg kg, lbf or tons
Summary	One ton of methanol burns in 1.5 tons of oxygen to give 1 and 3/8ths tons of carbon dioxide and 1 and 1/8th tons of water (vapour).

Octane (petrol)
balanced equation	2C₈H₁₈ + 25O₂ > 16CO₂ + 18H₂O
comprising	16 C 36 H 25 O₂ > 16 C 16 O₂ 36 H 9 O₂
molecular weights left side	1612 + 361 + 25216 = 1028
right side	1612 + 16216 + 361 + 9216 = 1028
octane	192 + 36 = 228
oxygen	25216 = 800
carbon dioxide	192 + 512 = 704
water	36 + 288 = 324
weights normalised to octane	228/228 = 1 800/228 = 3.509 704/228 = 3.09 324/228 = 1.42
Summary	One ton of octane burns in 3.5 tons of oxygen to give 3.1 tons of CO₂ and 1.42 tons of water (vapour).

Ethanol (ethyl alcohol) C2H6O or CH3 CH2 OH
balanced equation	2C₂H₆O + 3O₂ > 2CO₂ + 3H₂O
comprising	2C 6H 7O > 2C 6H 7O
molecular weights left side	212 + 61 + 16 + 3216 = 142
right side	212 + 2216 + 321 + 316 = 142
ethanol left side	24 + 6 + 16 = 46
oxygen left side	3216 = 96
carbon dioxide right side	2* (12 + 2*16) = 88
water right side	3* (2 + 16) = 54
weights normalised to ethanol	46/46 = 1 96/46 = 2.087 88/46 = 1.913 54/46 = 1.174
Summary	One ton of ethanol burns in 2.1 tons of oxygen to give 1.9 tons of CO₂ and 1.2 tons of water (vapour), approximately.