Nitrogen

Nitrogen has many commercial and technical applications based on its physical and chemical properties. Liquid nitrogen's cooling properties are used to freeze food, blood and other materials; modify metal properties; control reaction temperatures; cool concrete and simulate extremely cold operating conditions. Nitrogen gas is used to blanket, purge or stir many chemicals or molten metals. The gas can also be used to pressurize devices or pneumatically convey materials, while keeping out contaminates like oxygen or water
Nitrogen is colorless, odorless and tasteless. It is nonflammable, will not support combustion and is not life-supporting. The gas is slightly lighter than air and is only slightly soluble in water. When liquid nitrogen is vaporized and then heated it consumes a large amount of heat, making it an ideal coolant.
Nitrogen is present in the atmosphere at a concentration of 78.1%. Nitrogen is recovered from air in an Air Separation Unit (ASU) where it is drawn off as a cryogenic liquid at about -321°F. Nitrogen can then be distributed as a cryogenic liquid or as a gas in cylinders. Nitrogen can also be generated at the use point, using cryogenic, adsorption or membrane technologies.