Not to be confused with gasoline.
Natural gas (also called fossil gas; sometimes just gas), is a naturally occurring hydrocarbon gas mixture consisting primarily of methane, but commonly including varying amounts of other higher alkanes, and sometimes a small percentage of carbon dioxide, nitrogen, hydrogen sulfide, or helium.
It is formed when layers of decomposing plant and animal matter are exposed to intense heat and pressure under the surface of the Earth over millions of years.
The energy that the plants originally obtained from the sun is stored in the form of chemical bonds in the gas.
Natural gas is a fossil fuel.
The mining and consumption of natural gas is a major and growing driver of climate change.
Petroleum is another resource and fossil fuel found close to and with natural gas.
Most natural gas was created over time by two mechanisms: biogenic and thermogenic.
Deeper in the earth, at greater temperature and pressure, thermogenic gas is created from buried organic material.
In petroleum production, gas is sometimes burned as flare gas.
Before natural gas can be used as a fuel, most, but not all, must be processed to remove impurities, including water, to meet the specifications of marketable natural gas.
The by-products of this processing include ethane, propane, butanes, pentanes, and higher molecular weight hydrocarbons, hydrogen sulfide (which may be converted into pure sulfur), carbon dioxide, water vapor, and sometimes helium and nitrogen.
Natural gas is sometimes informally referred to simply as "gas", especially when it is being compared to other energy sources, such as oil or coal.
However, it is not to be confused with gasoline, which is often shortened in colloquial usage to "gas", especially in North America.
Natural gas was discovered accidentally in ancient China, as it resulted from the drilling for brines.
Natural gas was first used by the Chinese in about 500 BC (possibly even 1000 BC).
The discovery and identification of natural gas in the Americas happened in 1626.
In 1821, William Hart successfully dug the first natural gas well at Fredonia, New York, United States, which led to the formation of the Fredonia Gas Light Company.
The city of Philadelphia created the first municipally owned natural gas distribution venture in 1836.
By 2009, 66 000 km³ (or 8%) had been used out of the total 850 000 km³ of estimated remaining recoverable reserves of natural gas.
Based on an estimated 2015 world consumption rate of about 3400 km³ of gas per year, the total estimated remaining economically recoverable reserves of natural gas would last 250 years at current consumption rates.
An annual increase in usage of 2–3% could result in currently recoverable reserves lasting significantly less, perhaps as few as 80 to 100 years.
Credits to the contents of this page go to the authors of the corresponding Wikipedia page: en.wikipedia.org/wiki/Natural gas.