1 Nitrogen and Hydrogen are needed to make Ammonia
1.1 The nitrogen is obtained from air (78% nitrogen) the hydrogen comes from natural
gas or other sources like crude oil
2 Some of the nitrogen and hydrogen reacts to form Ammonia. Because the reaction is reversible, it occurs in both
directions. Ammonia can break down into nitrogen and hydrogen. The reaction reaches an equilibrium.
3 Higher pressures favour forward reaction so the pressure is set as high
as possible to give the best % yield without making it too expensive.
3.1 (200) atmospheres
3.1.1 The forward reaction is exothermic which means that increasing the temperature will actually move the
equilibrium the wrong way, so the yield of Ammonia would be greater at lower temperatures.
184.108.40.206 However, lower temp means lower rate of reaction so they increase the temp anyway to get a faster reaction. (450c) compromise.
4 Ammonia is formed as a gas but as it cools in the condenser, it liquefies and
id removed. The unused H and N are recycled so nothing is wasted