Heat Value of Natural Gas (MJ/m3 and BTU/SCF)

2021. 02. 23.

Heat Value of Natural Gas

What is the heat value of natural gas? It depends on the country and the pipelines, so the value can differ from 34 to 52 MJ/m3 (950 to 1,050 BTU/SCF).

Natural gas components

The components of natural gas determine the heat value of this fossil fuel. Natural gas mostly contains methane (91.3%), ethane (5%), propane (1.8%), butane (1%), nitrogen and carbon dioxide. It also contains hydrogen sulfide and helium in a very little amount.

Therefore, natural gas is an extremely flammable gas, which is odourless and colourless too. Natural gas producers add odour to the gas to make it less dangerous and to make leaking more noticeable.

Heat value of natural gas (in MJ/m3 and BTU/SCF)

The heat value of natural gas depends on how effective the thermal energy coming from the natural gas is. The heat content of natural gas is not related to the colour of the flame in the stove, nor to its colour or price.

“A megajoule per cubic meter (MJ/m³) is a decimal multiple of a derived unit of specific energy, heating value, energy content, or heat of combustion per unit volume.” Shortly: it shows how much energy (in megajoule) is released while combusting 1 cubic meter of natural gas.

1 MJ/m3 = 26.83 BTU/SCF (british thermal unit / cubic foot)

The heat content of natural gas might be different in various countries. For example, in Hungary, the heat value of natural gas has an average of 34.12 MJ/M3.

Other heating values:

  • Petrol / gasoline: 44-46 MJ/m3
  • Diesel fuel: 42-46 MJ/m3
  • Crude oil: 42-47 MJ/m3
  • Liquefied petroleum gas (LPG): 46-51 MJ/m3
  • Natural gas: 42-46 MJ/m3
  • Hard black coal (IEA definition): 23.9 MJ/m3
  • Firewood (dry): 16 MJ/m3

Source: https://www.world-nuclear.org/

However, the scale is not that wide: natural gas producers must meet a lot of quality criteria and parameters before exporting their product. A tool called chromatograph is measuring the quality of the natural gas and is able to determine the exported fossil fuels’ components, therefore its heating value will also be known.

The price is not set by the quantity of natural gas, but the quality and the heating value will determine how much an individual (or a country) will pay for this fuel.

The formula is simple:

Price of 1 m3 natural gas = volume (m3) x heat value (MJ/m3) x price (Currency/MJ) x VAT.

Is the heating value of natural gas decreasing?

Calorific value of natural gas

As time goes on, people will start to recognize that the heating value of natural gas is decreasing. It is not because of the quality they are receiving, but because the technology and heating systems become obsolete, thus the efficiency of these technologies will decrease.

Season factors also affect the “feel” of a decrease in heating value. For example, even tap water is colder in winter, so it takes more time to boil it.

Not just the maintenance of heating systems, but thermal insulation is also an important factor to have a better heating efficiency.

Conclusion

The heating value depends on

  • the components of the natural gas
  • the producers’ quality
  • and even the conditions of your home heating system