Ostwald process
From Academic Kids
The Ostwald process is an industrial process, invented by Wilhelm Ostwald, used to produce nitric acid.
Following production from the Haber process, ammonia is heated with a catalyst (platinum containing 10% rhodium) to form nitric oxide and water:
- 4 NH3 + 5 O2 → 4 NO + 6 H2O
The nitric oxide is then oxidized to yield nitrogen dioxide:
- 2 NO + O2 → 2 NO2
This in turn reacts with water to yield nitric acid and nitric oxide:
- 4 NO2 + O2 + 2 H2O → 4 HNO3(aq)
The conditions used in industry, which lead to about 96% conversion are:
- pressure between 4 and 10 atmospheres and
- temperatures between 975 and 1125 K.
Fixing nitrogen into ammonia and nitric acid was a key development in the production of fertilisers and explosives. Previously sources of Nitrogen had been Guano and Chilean saltpeter.
