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.
| Component | Typical Analysis (mole %) |
Range (mole %) |
|---|---|---|
| Methane | 94.6 | 93.1 - 96.1 |
| Ethane | 4.4 | 3.1 -5.7 |
| Propane | 0.2 | 0.09 - 0.2 |
| iso - Butane | 0.01 | trace - 0.02 |
| normal - Butane | 0.01 | trace - 0.03 |
| iso - Pentane | 0.003 | trace - 0.007 |
| normal - Pentane | 0.002 | trace - 0.005 |
| Hexanes plus | 0.002 | trace - 0.004 |
| Nitrogen | 0.4 | 0.3 - 0.45 |
| Carbon Dioxide | 0.3 | 0.19 - 0.51 |
| Oxygen | 0.005 | trace - 0.51 |
| Hydrogen | 0.01 | trace - 0.01 |
| Specific Gravity | 0.58 | 0.57 - 0.59 |
| Gross Heating Value (MJ/m3), dry basis * | 38.9 | 38.5 - 39.3 |
| Wobbe Number (MJ/m3) | 50.9 | 50.7 - 51.3 |
* 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).
