The Haber Process
- Ammonia is manufactured using the Haber Process
- More than 80% of the ammonia produced is used to produce fertiliser
- It is also used to make explosives and dyes
- The reactants are hydrogen and nitrogen which are extracted from methane and the air respectively
- The process occurs in five stages:
- Stage 1: H2 and N2 gases are pumped into the compressor through pipes
- Stage 2: The gases are compressed to about 200 atmospheres inside the compressor
- Stage 3: The pressurised gases are pumped into a tank containing layers of catalytic iron beads at a temperature of 450°C. Some of the hydrogen and nitrogen react to form ammonia in the following reversible reaction
N2 (g) + 3H2 (g) ⇌ 2NH3 (g)
- Stage 4: Unreacted H2 and N2 and product ammonia pass into a cooling tank.
- The ammonia is liquefied and removed to pressurised storage vessels
- Stage 5: The unreacted H2 and N2 gases are recycled back into the system
The production of ammonia by the Haber Process
Examiner Tip
The air contains 78% nitrogen and it is removed by fractional distillation. Hydrogen is derived from methane (CH4) in a process called steam reforming.
