Natural Gas

Based on its composition, extracted (biological) natural gas belongs to one of four basic groups.

• dry (weak) natural gas contains a high percentage of methane (95-98%) and a very small amount higher hydrocarbons
• wet (rich) natural gas contains more higher hydrocarbons in addition to methane
• acidic natural gas has a high content of sulfane (H2S), which must be removed in processing plants before natural gas is supplied to the distribution system
• natural gas with a high content of inert gases, i.e. mainly carbon dioxide and nitrogen

As to higher hydrocarbons, natural gas contains mainly saturated hydrocarbons, which under normal conditions exist in gaseous form – ethane, propane, and butane. Natural gas from some deposits also contains hydrocarbons that are in a liquid state under normal conditions (pentane and higher) and are separated as a gaseous condensate during processing. Their mixture is called gasoline or biological petrol. 

Examples of the composition of natural gas

At present, the most widely used natural gas is the so-called oil-based natural gas, which formed together with crude oil. In most cases, oil-based natural gas extracted together with crude oil is wet natural gas. Some deposits contain no crude oil, but only dry natural gas.

Besides oil-based gas, carbon-based natural gas is used, which is removed from coal during the mining process for safety reasons. This natural gas is always dry. Carbon-based natural gas is used in areas with anthracite mining.

Although the deposits of oil-based natural gas are sufficient, research is underway into ways of producing energy when all gas deposits will have been exhausted. One possibility is producing substitute natural gas through coal gasification. The principle of making oil-based natural gas can be described by the following formula:

Coal + H ₂O = CH ₄ + CO ₂

Production of oil-based natural gas is currently disadvantageous from the economic viewpoint.