The Haber Process
Ammonia is manufactured on a large scale by the invented in 1908 by Fritz Haber as a practical method of making nitrogen compounds from nitrogen gas.
Originally, Haber invented the process to make explosives from ammonia. However, the Haber process soon became the main source of ammonia for making nitrogen fertilisers.
In the Haber process, nitrogen and hydrogen gases are mixed together the ratio of 1:3. The nitrogen is obtained from the air, while the hydrogen is obtained from natural gas. The mixture is passed over an iron catalyst (Figure 2.17).
The equation for the reaction producing ammonia is:
nitrogen + hydrogen→ ammonia
N2 (g)+ 3H2 (g) →2NH3 (g) + heat
The ammonia gas formed is condensed a liquid. Unreacted nitrogen into and hydrogen are recycled. Modern ammonia plants produce 1000 to 7000 tonnes of ammonia a day.
The Haber process is an efficient chemical process. Nitrogen from the air, hydrogen from natural gas and iron for the catalyst are plentiful and cheap. There are no waste products and the process can produce unlimited amounts of ammonia .The heat given out in the reaction is not wasted but is used to keep the catalyst hot and to heat the gases entering the catalyst chamber.