Revision:Manufacture of ammonia

Uses of ammonia

  • Manufacture of nitric acid
  • Fertilisers (ammonium sulphate)
  • Manufacture of fibres (nylons, dyes)

Raw materials of ammonia

  • N2 gas obtained from the air
  • H2 gas obtained from methane


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  • Methane is heated with steam to produce hydrogen

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Temperature of approx. 450 degrees because a low temperature moves the equilibrium in the exothermic direction therefore the yield of ammonia is increased. However at a low temperature, the rate of production of ammonia is very slow.

There a four mols of gas on the left and 2 on the right of the equation so a low pressure will move the equilibrium position to the right hand side.

An iron catalyst is used to increase the rate of attainment of the equilibrium.


Because the reaction is exothermic, the energy released is used to maintain the temperature of the system.

Unreacted H2 and N2 are reused.