Natural 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 used as a source of energy for
heating, cooking, and electricity generation. It is also used as
fuel for vehicles and as a chemical feedstock in the manufacture of
plastics and other commercially important organic chemicals. Fossil
fuel based natural gas is a non-renewable resource.
Natural gas is found in deep underground rock formations or
associated with other hydrocarbon reservoirs in coal beds and as
methane clathrates. Petroleum is another resource and fossil fuel
found in close proximity to and with natural gas. Most natural gas
was created over time by two mechanisms: biogenic and thermogenic.
Biogenic gas is created by methanogenic organisms in marshes, bogs,
landfills, and shallow sediments. Deeper in the earth, at greater
temperature and pressure, thermogenic gas is created from buried
organic material.
