Example 8.2: Calculate GHG carbon dioxide (CO₂) emissions per unit  release of energy when methane is completely burned.

Solution:

Complete   or stoichiometric combustion reaction of methane in air is;

Mass of reactants

Methane   + Air                        =  CO2  +  Water  +  Nitrogen
16            + 2 (32 + 3.76 x28)   =  44     + 2x 18    +  2 x3.76x 28

16            + 274.56                                  44      +  36                  + 210.56

From  Example 1 the energy released when 1 kg of methane is burned =  50 MJ/kg the above
CO₂ produced per kg of methane burned =  44/16 = 2.75 kg CO₂/kg of methane

CO₂ produced = 2.75/50 = 0.055 kg/MJ or 55 g/MJ of energy released.                 Ans