(NH3) Anhydrous Ammonia
A colorless , flammable, toxic, alkaline gas shipped as a
liquefied gas at its vapor pressure of 116.7 psig at 70°F
(21°C). It causes burns on contact with eyes, skin, and mucous
membranes.
- Anhydrous ammonia is one of the oldest
commercial refrigerants known. Its most extensive use
(about 80%) is in soil fertilization as a source of
nitrogen, which is essential for plant growth. Other uses
include metal treating operations such as nitriding,
sintering, and furnace brazing. Ammonia is also used the
chemical industry to make a host of products. Gunpowder
and sulfuric acid are a couple of well known products
that use ammonia as an ingredient.
- Ammonia is produced primarily by the Haber
process whereby nitrogen and hydrogen are combined
directly. A less important method is the calcium
cyanamide process which produces ammonia directly from
limestone, carbon, nitrogen, and steam. Also some ammonia
is produced from the destructive distillation of coal.
- Under appropriate regulations, anhydrous
ammonia is transported as a liquefied compressed gas in
cylinders, insulated and un-insulated tank cars, barges,
and tankers. It is stored in bulk in large capacity
containers installed above or below ground. Normal above
ground storage is un-insulated pressure storage
tanks.Very large aboveground storage containers are often
low pressure, refrigerated, and consequently insulated.
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