1. Chemsheets AS006 (Electron arrangement)
14/04/2017
HABER PROCESS
© GCSE Jul-13

2. NH3

3. PRODUCTION OF AMMONIA
Millions of tonnes per year
NH3

4. MAKING AMMONIA
fertiliser
cleaning fluid

5. MAKING AMMONIA N2(g) + 3 H2(g)  2 NH3(g)
RAW MATERIALS
methane
+ steam
air
N2(g) H2(g)  2 NH3(g)
nitrogen
hydrogen
ammonia
© GCSE Jul-13

7. MAKING AMMONIA N2(g) + 3 H2(g)  2 NH3(g)
exothermic
N2(g) H2(g)  2 NH3(g)
endothermic
4 molecules molecules
more pressure less pressure
© GCSE Jul-13

8. MAKING AMMONIA

9. MAKING AMMONIA N2(g) + 3 H2(g)  2 NH3(g)
Temperature 450ºC
Lower temperature → more NH3
Reaction exothermic
Higher temperature → faster
Compromise between yield & rate
Pressure 200 atm
Higher pressure → more NH3
4 molecules → 2 molecules
Higher pressure → very expensive
Compromise between yield & cost
Catalyst iron
Speeds up reaction
No effect on yield of NH3
© GCSE Jul-13

10. MAKING AMMONIA N2(g) + 3 H2(g)  2 NH3(g)
NH3 is removed by cooling (forms a liquid).
Less than 30% yield, so the unreacted H2 and N2 are recycled.
© GCSE Jul-13