Fuel Calorific Values



The calorific value of a fuel is the quantity of heat produced by its combustion – at constant pressure and under “normal”  (standard) conditions (i.e. to 0oC and under a pressure of 1,013 mbar).

The combustion process generates water vapor and certain techniques may be used to recover the quantity of heat contained in this water vapor by condensing it.

  • Higher Calorific Value (or Gross Calorific Value – GCV, or Higher Heating Value – HHV) – the water of combustion is entirely condensed and that the heat contained in the water vapor is recovered;
  • Lower Calorific Value (or Net Calorific Value – NCV, or Lower Heating Value – LHV) – the products of combustion contains the water vapor and that the heat in the water vapor is not recovered.

Arrow Right   Fuel Calorific Values



Natural gas 12500 kcal/kg
Propane-butane 11950 kcal/kg
Disel 10000 kcal/kg
Fuel oil 9520 kcal/kg
Brown coal 3500 kcal/kg
Woods 2500 kcal/kg
Electricity 860 kcal/kWh

Arrow Right 1 cubic meter of Methane weighs 0.717 kg/m³

Arrow Right   1 kW is obtained from:

0.072 kg natural gas
0,073 kg propane-butane
0,083 kg gasoline
0,085 kg disel
0,092 kg fuel oil
0,124 kg charcoal
0,144 kg coal
0,218 kg brown coal

Arrow Right   Composition of Natural Gas

Methane CH4 70-90%
Ethane C2H6 0-20%
Propane C3H8 Butane C4H10 Carbon Dioxide CO2 0-8%
Oxygen O2 0-0.2%
Nitrogen N2 0-5%
Hydrogen sulphide H2 S 0-5%
Rare gasesA, He, Ne, Xe trace




5 thoughts on “Fuel Calorific Values

  1. Jorge Martins

    Would the Calorific Values presented High or Low? I mean, should they be compared to High Heating Values or to Low Heating Values?

    Reply
  2. Martin

    I am sorry, but a lot of mistakes in the tables provided.

    First the dimensions: it says that 0.072 kg of NG gives 1 KW; actually this should be 1 kJ or alternatively it could have been 0.072 kg/s (consumption) delivers 1 KW.

    Second, it is unclear what is meant here. I assume we are talking about the caloric value translated into “heat” and not “power”. If power is meant then much more is wrong with the tables. However, if it is combustion value (heat) also the calculation is wrong.

    1 kg of NG is approx. 52000 kJ/kg caloric value which fits with 12500 kcal/kg. Then 0.072 kg of NG gives me 0.072 x 52000 = 3744 kJ -OR- 0.072 kg/s NG gives me 3,744 kW (and not 1 KW as quoted). So either there is a huge mistake, or the KW figure is electricity and inefficiencies/losses of E-generation are taken into account. However, then it does not fit with other fuels quoted.

    So please update your data.

    Martin

    Reply
  3. Martin

    further calcls give me:

    1 kWh is 1 KW power during 3600 secs, which is
    1 kJ/s during 3600 secs, which is
    (1/52300) (kJ/s divided by kJ/kg) during 3600 s, which is
    (1/52300) x 3600 kg NG = 0.0688 kg NG, which is close to the 0.072 kg NG per KWh.

    In other words: the second table should be defined as the amount of fuel to generate 1 kWh. But again this is thermal and not yet electricity.

    Martin

    Reply

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