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Nitrogen, or N2, is a diatomic gas which comprises
78 percent of the earth's atmosphere. In addition to air,
nitrogen is found in the protein matter of all life forms,
in some natural gas-hydrocarbon deposits, and in many organic
and inorganic compounds.
Colorless, odorless, tasteless, and nontoxic, nitrogen exists
as a non-flammable gas at atmospheric temperatures and pressures.
A specific gravity of .9669 makes nitrogen slightly lighter
than air. When cooled to its boiling point of -320°F,
nitrogen becomes a colorless liquid which can, in turn, be
compressed into a colorless, crystalline solid. It is only
slightly soluble in water and most other liquids, and is a
poor conductor of heat and electricity.
Most uses of gaseous nitrogen depend on its inert characteristics.
At high temperatures and pressures, however, it will combine
with some reactive metals (such as lithium and magnesium)
to form nitrides, as well as with some gaseous elements such
as hydrogen and oxygen.
Nitrogen finds use in diverse commercial applications, including:
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Chemical Processing ...
to inert vessels and oxygen-sensitive chemicals, creating
an oxygen-deficient environment that reduces safety hazards;
to propel liquids through pipelines; and to manufacture
ammonia. |
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Food ... to extend shelf-life
in packaged foods by preventing spoilage from oxidation,
mold growth, moisture migration and insect infestation;
to rapidly freeze; and to refrigerate perishables during
transport. |
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Metal Production and Fabrication
... to protect metals such as steel, copper and
aluminum during annealing, carburizing and sintering operations
in high temperature furnaces; to cool extrusion dies;
and to shrink fit metal parts; utilized as a purge gas
with stainless steel tube welding. Also used to support
plasma cutting. |
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Electronics ... to prevent
oxidation in the manufacture of semiconductors and printed
circuits; and to enhance solvent recovery systems by eliminating
the use of chlorofluorocarbons for cleanup. |
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Glass Manufacturing ...
to cool furnace electrodes and prevent oxidation during
manufacturing; and to lower air temperatures for optimum
cooling rates. |
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Research and Health Services
... to freeze and preserve blood, tissue, semen
and other biological specimens; to freeze and destroy
diseased tissue in cryosurgery and dermatology; and to
pre-cool or insulate Magnetic Resonance Imaging (MRI),
conserving the more costly helium. |
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Construction ... to suppress
the pour temperature of concrete mixtures, inhibiting
the formation of cracks; and to stabilize the ground as
in the restoration of the Leaning Tower of Pisa. |
Although nontoxic and inert, nitrogen can act as a simple asphyxiant
by displacing needed oxygen in the air. Liquid nitrogen may
cause severe frostbite to the eyes and skin. To avoid these
harmful effects, producers and customers should follow strict
safety guidelines for storage and handling, and consult nitrogen
Material Safety Data Sheets.
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Nitrogen, MSDS |
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Nitrogen (Liquid), MSDS |
Customers can obtain nitrogen through a variety of supply
options, including:
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Bulk liquid delivery in tank trucks |
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Bulk gas delivery by tube trailer trucks |
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Cylinders |
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Portable insulated containers called dewars |
Nitrogen...Facts
Nitrogen's low boiling point and non-toxic
properties make it an economical choice for recycling tires
through cryopulverization. In this process, liquid nitrogen
serves as a freezing agent and embrittles shredded tire scrap
so that it can be easily ground into crumb rubber. The resulting
product finds use in roofing materials, sealants, oil well
linings, recreational surfaces and asphalt paving.
A similar process is used to grind and sort polyvinyl chloride
from post-consumer scrap in mixed waste loads, as well as
to grind and process dried fruits, delicate herbs and spices.
Nitrogen, one of the largest volume industrial gases, is
produced commercially as a gas or as a liquid by several methods.
These include:
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Cryogenic Air separation, a process in which air is
compressed and cooled to cryogenic temperatures, liquefied
and then, relying on different boiling points, separated
into its components in a distillation column. This can
be done in a co-products plant producing nitrogen, oxygen
and argon, or in a Nitrogen Plant (N-Plant) which produces
high purity nitrogen only. |
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Membrane separation, a non-cryogenic technology that
uses hollow-fiber polymer membranes to separate gaseous
nitrogen from air by selective permeability. Membrane
nitrogen is usually lower cost than cryogenically produced
nitrogen, but it is also lower purity. |
Cryogenic distillation accounts for approximately 85 percent
of nitrogen production. It is the preferred supply mode for
high volume and high purity requirements. Membrane systems
are preferred because of their lower cost and simplicity for
smaller and lower purity requirements.
Select a gas from the list of the below for more information
about gas applications and supply options.
| » Atmospheric Gases |
» Process Gases |
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| » Gases & Mixtures for Specific Applications |
» Rare Gases |
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