Stoichiometric or Theoretical Air Quantity
Theoretical Air Quality is calculated based on the chemical reaction between the elements and oxygen.
- Carbon combines with oxygen to form carbon-dioxide and heat.
C+ O2 > CO2
1 C +32/12 O > 44/12 CO2
1 kg Carbon +2.67 kg Oxygen > 3.67 kg Carbon Dioxide
- Hydrogen combines with oxygen to form water and heat
2 H2+ O2> 2H2O
1 H +32/4 O >36/4 H2O
1 kg Hydrogen +8 kg Oxygen >9 kg Water
- Sulphur combines with oxygen to form sulphur dioxide
S + O2 > SO2
1 S +32 /32 O >64 /32 SO2
1 kg Sulphur +1 kg Oxygen >2 kg Sulphur Dioxide.
For this example, we are considering coal having a makeup of 57.2 % Carbon, 2.2 % Hydrogen , 0.5 % Sulphur and 6.9 % Oxygen.
- The theoretical oxygen required to burn this coal is then
2.67 x C % + 8 x H% + 1 x S % - O% = 1.64 kg of Oxygen for 1 kg of Coal.
Air contains 23.2% by weight of oxygen.
- The theoretical air required to burn the coal is
= 1.64 / 23.2% = 7.1 kg of Air for 1 kg of Coal.
This is the theoretical air required to burn the coal.