Abstract

Nitrogen is an important industrial gas and an element that is essential to all life. Most naturally occurring, noncombined nitrogen exists as a diatomic gas sometimes referred to as dinitrogen. Dinitrogen is an extremely stable, relatively inert molecule. High temperatures are generally required to coax its reactivity. Due to its inert nature, gaseous nitrogen finds wide application in many industrial processes as a blanketing and purging agent. Dinitrogen liquifies at –196°C to a colorless liquid. Liquid nitrogen is used in many applications as an inert, expendable refrigerant. All commercial nitrogen uses atmospheric air as the feedstock. The principal manufacturing processes include cryogenic distillation, pressure swing adsorption, membrane permeation, and combustion-based processes. At the present time, cryogenic distillation is the most significant. Commercial nitrogen is distributed in very large volumes by pipeline or in smaller volumes in liquified form for use or vaporization at the use point or in compressed gaseous form in steel cylinders. Nitrogen is nontoxic but does not support life, therefore care is required before entering areas suspected of being nitrogen-enriched.