Tag: calorific value

Calorific value is a measure of heating capacity of fuel. It gives the fuel efficiency.

The calorific value of a fuel is the quantity of heat produced by its combustion - at constant pressure and under a conditions known as " normal " of temperature and pressure (i.e. to 0oC and under a pressure of 1,013 mbar). 
The combustion of a fuel product generates water vapor. Certain techniques are used to recover the quantity of heat contained in this water vapor by condensing it. 
The Higher Calorific Value (or Gross Calorific Value - GCV) supposes that the water of combustion is entirely condensed and that the heat contained in the water vapor is recovered. 
The Lower Calorific Value (or Net Calorific Value - NCV) supposes that the products of combustion contains the water vapor. The heat contained in the water vapor is not recovered. 
LPG has a typical specific calorific value of 46.1 MJ/kg.
Calorific value of Bio gas is about 19 to 25 MJ/cubic meter, depending on the methane percentage in the biogas mix.
Heat of combustion of kerosene for lower heating value is 43.1 MJ/kg, and for higher heating value is 46.2 MJ/kg.
Petrol, calorific value of which is 45.8 MJ/kg.
Thus, LPG has highest calorific value among above.

Calorific value is the amount of energy produced by the complete combustion of a molecule. Amongst the given options, $H _{2}$ has the highest calorific value.