Natural gas

[3][4] Because natural gas is odorless, odorizers such as mercaptan (which smells like rotten eggs) are commonly added to it for safety so that leaks can be readily detected.

[5] Natural gas is a fossil fuel that is formed when layers of organic matter (primarily marine microorganisms)[6] are thermally decomposed under oxygen-free conditions, subjected to intense heat and pressure underground over millions of years.

When burned for heat or electricity, natural gas emits fewer toxic air pollutants, less carbon dioxide, and almost no particulate matter compared to other fossil and biomass fuels.

Thermogenic gas takes a much longer period of time to form and is created when organic matter is heated and compressed deep underground.

"[16] In order to highlight its role in exacerbating the climate crisis, however, many organizations have criticized the continued use of the word "natural" in referring to the gas.

[17][18][19] A 2020 study of Americans' perceptions of the fuel found that, across political identifications, the term "methane gas" led to better estimates of its harms and risks.

The large volumes produced could not be used until relatively expensive pipeline and storage facilities were constructed to deliver the gas to consumer markets.

Gas venting and production flaring are still practised in modern times, but efforts are ongoing around the world to retire them, and to replace them with other commercially viable and useful alternatives.

[32] It sometimes contains a significant amount of ethane, propane, butane, and pentane—heavier hydrocarbons removed for commercial use prior to the methane being sold as a consumer fuel or chemical plant feedstock.

Sources that consider that Russia has by far the largest proven reserves include the US Central Intelligence Agency (47,600 km3)[34] and Energy Information Administration (47,800 km3),[35][36] as well as the Organization of Petroleum Exporting Countries (48,700 km3).

[39] In turn, many studies from MIT, Black & Veatch and the US Department of Energy predict that natural gas will account for a larger portion of electricity generation and heat in the future.

"[43] Following the increased production in the United States, shale gas exploration is beginning in countries such as Poland, China, and South Africa.

[47] In late 2020, China National Petroleum Corporation claimed daily production of 20 million cubic meters of gas from its Changning-Weiyuan demonstration zone.

Most town "gashouses" located in the eastern US in the late 19th and early 20th centuries were simple by-product coke ovens that heated bituminous coal in air-tight chambers.

The coal tar (or asphalt) that collected in the bottoms of the gashouse ovens was often used for roofing and other waterproofing purposes, and when mixed with sand and gravel was used for paving streets.

Huge quantities of natural gas (primarily methane) exist in the form of clathrates under sediment on offshore continental shelves and on land in arctic regions that experience permafrost, such as those in Siberia.

The large trade cost implies that natural gas markets are globally much less integrated, causing significant price differences across countries.

Usually sales quality gas that has been treated to remove contamination is traded on a "dry gas" basis and is required to be commercially free from objectionable odours, materials, and dust or other solid or liquid matter, waxes, gums and gum forming constituents, which might damage or adversely affect operation of equipment downstream of the custody transfer point.

As a further option, the gas is now sometimes re-injected into the formation for enhanced oil recovery by pressure maintenance as well as miscible or immiscible flooding.

Conservation, re-injection, or flaring of natural gas associated with oil is primarily dependent on proximity to markets (pipelines), and regulatory restrictions.

[4] Natural gas dispensed in a residential setting can generate temperatures in excess of 1,100 °C (2,000 °F) making it a powerful domestic cooking and heating fuel.

[4] In much of the developed world it is supplied through pipes to homes, where it is used for many purposes including ranges and ovens, heating/cooling, outdoor and portable grills, and central heating.

Raw material for large-scale fuel production using gas-to-liquid (GTL) process (e.g. to produce sulphur-and aromatic-free diesel with low-emission combustion).

[112] After release to the atmosphere, methane is removed by gradual oxidation to carbon dioxide and water by hydroxyl radicals (OH−) formed in the troposphere or stratosphere, giving the overall chemical reaction CH4 + 2O2 → CO2 + 2H2O.

In Amsterdam, no new residential gas accounts have been allowed since 2018, and all homes in the city are expected to be converted by 2040 to use the excess heat from adjacent industrial buildings and operations.

Sand and other particles are added to the water as a proppant to keep the fractures in the rock open, thus enabling the gas to flow into the casing and then to the surface.

In the US, the New London School explosion that occurred in 1937 in Texas caused a push for legislation requiring the addition of an odorant to assist consumers in detecting leaks.

Many building codes now forbid the installation of gas pipes inside cavity walls or below floor boards to mitigate against this risk.

Moreover, it would help to resolve supply and global warming issues,[171] as well as strengthen relations with other Mediterranean countries and foster investments in the region.

A gigajoule (GJ) is a measure approximately equal to 80 litres (0.5 barrels) of oil, or 28 m3 or 1,000 cu ft or 1 million BTUs of gas.