Background, how we make them and the good and the bad
Overview of Fertliser
How long they've been around
Fertilisers have been used by farmers to aid plant nutrition for thousands of years. John Bennet Lawes was one of the first scientists to begin experimenting with the effects of manure on plant growth.
Industrial nitrogen based fertiliser was developed by Kristian Birkeland in 1903, nitrogen is placed in the fertiliser as the plants absorb the nitrate ions. The reaction used to produce this nitrogen based fertiliser was HNO3 → H+ + NO3-.
The Haber Process
The raw materials used in the haber process are hydrogen and nitogen. The hydrogen gas is obtained by reacting methene with steam and the nitrogen is obtained through the burning of hydrogen.
The nitrogen and hydrogen will react together under these conditions:
- At a very high temperature (400 degrees)
- Under very high pressure (200 times normal pressure)
- An iron catalyst is used.
When nitrogen and hydrogen are reacted together ammonia is formed. Ammonia is used in fertilisers. The reaction of nitrogen + hydrogen ammonia can work both backwards and forwards. This means that nitrogena and hydrogen can be reacted together to form ammonia and ammonia can be broken up into hydrogen and hydrogen.