Page 16 - Curriculum Visions Dynamic Book

Making ammonia industrially
The industrial method of making ammonia is called the Haber–Bosch process after its inventors. In the process, nitrogen and hydrogen 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 is a catalyst
in the reaction and so remains unchanged.
The ammonia produced is liquified to separate it from the unreacted gases, which are then recycled.
Limitations of the Haber–Bosch process
This process has produced the foundation material for important fertilisers and has thus greatly contributed to the increase in the world’s food supply. However, the process consumes large amounts of energy and the equipment, operating at high temperatures and pressures, is expensive to make.
The source of hydrogen from the reaction
is mainly petroleum, a nonrenewable fossil fuel. For this reason, fertilisers are expensive and scientists are looking for a natural way to fix nitrogen for use as a fertiliser.
Nitrogen
Hydrogen
EQUATION: Production of ammonia by the Haber-Bosch process
The mixture of gases is put under great pressure and heated to a high temperature.
Hydrogen+ nitrogen ➪ ammonia 3H2(g) + N2(g) ➪ 2NH3(g)
Ammonia molecules
Hydrogen
Nitrogen
+
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