In this process, a mixture of pure nitrogen and hydrogen in the ratio 1 :3 by volumes are allowed to react. The basic problem in ammonia synthesis is that it is a reversible reaction and can be described as:
To get maximum yield of ammonia, the optimum condition of temperature should be 400-450°C, that of pressure should be 200-250 atmosphere and the appropriate catalyst Fe2O3 (Ferric oxide) with the small amount of Al2O3, CaO, K2O are required. Ammonia thus obtained is liquefied by cooling, the unused gases are recirculated over the catalyst for the further formation of ammonia. Millions of tons of ammonia are prepared annually by this method fig. describes the industrial preparation of ammonia by Haber’s process.