Reducing atmosphere Reducing atmosphere A reducing atmosphere is an atmospheric condition in which oxidation is prevented by removal of oxygen and other oxidizing gases or vapours, and which may contain actively reducing gases such as hydrogen, carbon monoxide, and gases such as hydrogen sulphide that would be oxidized by any present oxygen. In metal processing, a reducing atmosphere is used in annealing ovens for relaxation of metal stresses without corroding the metal. A non oxidizing gas, usually nitrogen, is used, or for more extreme conditions, hydrogen gas. A reducing atmosphere is also used to produce specific effects on ceramic wares being fired.
Flash-gas (petroleum) to its combustion. As of 2009, energy-related CO emissions made up more than 80% of total U.S. greenhouse gas emissions. Flare and flash gas both contain GHGs and therefore contribute to their release into the atmosphere, estimates of their emission levels during petroleum production vary due to largely unmeasured release of flash gas and other forms of fugitive emissions. One study estimated a 40% increase in the atmospheric concentration of the GHG carbon dioxide (CO) is due directly to human activities since 1750. GHGs other than CO which are produced during petroleum operations are also a concern to the environment.