Page 16 - Curriculum Visions Dynamic Book

Hydrogen for ammonia
About a half of all the hydrogen produced in industry is used for making ammonia. Ammonia is one of the foundation materials
for the manufacture of artificial fertilisers. These fertilisers, in turn, are vital for boosting the world’s food supply.
Ammonia
Ammonia is a compound of nitrogen and hydrogen. It is easy to detect because it has
a strong, irritating smell. It is
a colourless gas, not actually poisonous, but breathing in its fumes can cause people to stop breathing, so it can have very serious effects.
Ammonia is extremely soluble in water, where it produces an alkaline liquid called ammonium hydroxide. This dilute solution
is commonly sold for use as a household disinfectant and cleaning agent under the title “household ammonia”.
Making ammonia
The method of making ammonia is called the Haber–Bosch process after its inventors.
In the process, hydrogen and nitrogen gases are reacted at high temperatures (up to 600°C) and high pressures (up to 600 atmospheres).
The reaction works best if this is done in the presence of iron, although iron plays no part in the actual reaction (it is a catalyst for this reaction).
The ammonia produced is liquified to separate it from any unreacted gases, and these are then recycled.
 This is part of a Haber–Bosch ammonia plant. These pipes are recycling some of the unreacted gases.
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