In 1908, a German Chemist Fritz Haber (1868~1934) had discovered the Haber process which is considered one of the crucial invention in the 20th century. At that time, the major method to produce the ammonia was extracting from the nature Chile saltpeter, which is sodium nitrate.
Ammonia is very useful materials, that is used for washing, chemical fertilizer and an explosive compound. Thus, it is used for wide range of purposes. However, it was hard for getting the ammonia by abstracting it from the Chile saltpeter for two major reasons. One is that Chile peter is located in the cave wall so that it was hard for mining it.
Another reason is that for producing the ammonia, people needed to decompose the large amount of excrements from the animal. At the beginning of the 20th century, there was a concerned raised that since the agriculture has been increased a lot in worldwide, the ammonia supply was scanty. Thus the supply could not be satisfied as the farmers demanded. The invention that Haber made was using the production way for producing the lots of ammonia plentifully. He extracted the hydrogen gas from the methane, then make it to have a chemical reaction with the nitrogen in the atmosphere. In order to accomplish this, the Catalyst is needed. During the experiment, Haber realized that iron is the best Catalyst, so that he used high pressure to have chemical reaction between hydrogen and nitrogen with iron, and produced huge amount of NH3, which is ammonia.
Manufacturing the ammonia makes people to produce soluble nitrogen containing fertilizers, which have revolutionized agriculture and led to enormous increases in food production. It is a based on the reversible equation which is nitrogen + hydrogen ? ammonia. At room temperature with having the normal pressure is not producing the ammonia. This Haber changed the conditions so that the forward reaction was favored. The forward reaction of the Haber process is exothermic, so a low temperature will promote this and yield more ammonia at equilibrium. Thus, a medium temperature, about 450 C is chosen.
A high pressure of 200 atmospheres is normally used, since increasing the pressure will lead to more ammonia at equilibrium. Catalyst is also important for its reaction. Without a catalyst, which is iron for this reaction, the reactions in both the forward and reverse directions will be very slow. Thus the Catalysts helps the reaction reach equilibrium with a fast speed.