The category is Natural Gas: Natural gas (also called fossil gas; sometimes just gas), is a naturally occurring hydrocarbon gas mixture consisting chiefly of methane, but commonly including changing amounts of other higher alkanes, and occasionally a small percentage of carbon dioxide, nitrogen, hydrogen sulphide, or helium.
Parent categories: Metallurgy, Plastics, Rubber, Chemicals & Energies
Related categories: All categories that are energy related, visitor discretion required