Page 109 - Encyclopedia of Chemical Compounds 3 Vols

AMMONIA

Ammonia. Blue atom is
nitrogen and white atoms are
hydrogen. PU BL I S HERS
RESOURCE GRO U P

the list of all chemicals produced by volume. About 90 percent
of all the ammonia used in the United States goes to the
production of fertilizers.

HOW IT IS MADE
Ammonia is produced naturally by the action of certain
types of bacteria on nitrogen found in the atmosphere. It is
also formed during the decay of dead organisms.
Until the end of the nineteenth century, ammonia was
produced commercially by the cyanamide process. Calcium
carbide (CaC 2 ), nitrogen gas (N 2 ), and steam were reacted
with each other to produce ammonia.
In the early 1900s, the German chemist Fritz Haber
(1868–1934) developed a method for making ammonia
directly from its elements, nitrogen and hydrogen. The two
gases are combined with each other at high temperature

(400 C to 650 C; 750 F to 1200 F) and pressure (200 to 400
atmospheres; 3,000 to 6,000 pounds per square inch) over a
catalyst made of finely-divided iron. Haber’s process was later
refined and improved by German chemical engineer Carl
Bosch (1874–1940). Haber and Bosch both won Nobel Prizes
in chemistry for their work on the production of ammonia.
The Haber-Bosch process remains the most common form of
ammonia production in many countries, including the United

58 CHEMICAL COMPOUNDS