Forming gas treatment of metals, because it reduces oxides on the metal surface. Forming gas Forming gas is a mixture of hydrogen (mole fraction varies) and nitrogen. It is sometimes called a "dissociated ammonia atmosphere" due to the reaction which generates it: It can also be manufactured by thermal cracking of ammonia, in an ammonia cracker or forming gas generator. Forming gas is used as an atmosphere for processes that need the properties of hydrogen gas. Typical forming gas formulations (5% H2 in N2) are not explosive. It is used in chambers for gas hypersensitization, a process in which photographic film is
Natural gas in the United States sold to refineries the same as oil. The C2 through C5 hydrocarbons (ethane, propane, butane, and pentane) are known as natural gas liquids (NGLs), and remain in gaseous form until they are extracted at a gas processing plant. The division between the two classes is not perfect: some hexane, and heptane remain in the gas to be separated out as NGLs, while some butane and pentane, may separate out with the condensate. Natural gas which contains NGLs is called "wet gas." Gas which naturally contains no NGLs, or gas from which the NGLs have been removed, is called "dry gas."