Natural gas is methane that comes from buried plants and animals which decayed and formed tiny bubbles of gas that is gathered, cleaned and used as an energy source.

Chemical composition of natural gas

Natural gas is a naturally occurring gas mixture, consisting mainly of methane sourced from supply basins in western Canada, the United States and Ontario producers.

Composition is an overall system average and may vary from the typical value listed below by location.

Natural gas composition components
Component Typical Analysis
(mole %)
Range
(mole %)
Methane 94.7 87.0 - 98.0
Ethane 4.2 1.5 - 9.0
Propane 0.2 0.1 - 1.5
iso - Butane 0.02 trace - 0.3
normal - Butane 0.02 trace - 0.3
iso - Pentane 0.01 trace - 0.04
normal - Pentane 0.01 trace - 0.04
Hexanes plus 0.01 trace - 0.06
Nitrogen 0.5 0.2 - 5.5
Carbon Dioxide 0.3 0.05 - 1.0
Oxygen 0.01 trace - 0.1
Hydrogen 0.02 trace - 0.05
Specific Gravity 0.58 0.57 - 0.62
Gross Heating Value (MJ/m3), dry basis * 38.8 36.0 - 40.2
Wobbe Number (MJ/m3) 50.9 47.5 - 51.5

* The gross heating value is the total heat obtained by complete combustion at constant pressure of a unit volume of gas in air, including the heat released by condensing the water vapour in the combustion products (gas, air, and combustion products taken at standard temperature and pressure).

Sulphur: In the Enbridge Gas system, the typical Sulphur content is from 3 - 6 mg/m3.

Water vapour: The water vapour content of natural gas in the Enbridge Gas system is less than 65 mg/m3 and is typically 16 - 32 mg/m3.

Typical combustion properties of natural gas:

  • Ignition Point: 564 oC *
  • Flammability Limits: 4% - 15% (volume % in air) *
  • Theoretical Flame Temperature (stoichiometric air/fuel ratio): 1953 oC *
  • Maximum Flame Velocity: 0.36 m/s *

* The properties shown are an overall average on the Enbridge Gas system and may vary at your location. Information provided is from the Ortech Report No. 26392, Combustion Property Calculations for a typical Union Gas Composition, 2017.