Naturally occurring gas that primarily contains methane, CH₄. A fossil fuel like coal and petroleum, it is the hottest and cleanest burning of these fuels and is increasingly touted as a substitute for petroleum. It is, however, an explosion hazard in coal mines and an unwanted byproduct of anaerobic digestion in landfills. It is most commonly found with petroleum or at depths which vaporize oil. Use is hampered by transportation difficulties and risks, and thus it is limited to pipelines and compression tanks. Huge quantities exist as unconventional sources, including coal gasification and conversion to methanol.

See Also

Liquified Natural Gas