Natural gas is a fossil fuel formed by the decomposition of organic substances. It is a mixture of various gases, comprising mostly methane or CH4 (up to 99%). Also present are ethane, propane, butane, particles of heavy hydrocarbons, nitrogen and carbon dioxide. Natural gas is extracted from underground deposits and then transmitted to users via underground gas transmission networks.

Natural gas is the cleanest fossil fuel, with the lowest CO2 emissions when burned. It serves multiple purposes and is energy efficient. Natural gas is non-toxic. It is lighter than air, odourless and is explosive in the right combination with air. Thus, for safety reasons an odorant is added to natural gas in the distribution process in order to detect its presence.

CO2 and H2O are generated when methane is burned and chemical energy is converted to heat. The abbreviation NG is used to designate natural gas.

Basic technical information about natural gas:

Gross calorific value: (kJ/Sm3) → From 36,000 to 40,000

Wobbe number (MJ/Sm3) → From 48 to 52

Density (kg/Sm3) → From 0,6 to 0,8

Relative density (air = 1) → From 0,54 to 0,59

Sm3 = standard cubic meter (15ºC and 1.01325 bar)