Classical production of
mineral nitrogen fertilizer

[Motivation, Idea Identification]

The Haber-Bosch-process was developed of two chemists named Fritz Haber and Carl Bosch. They received the 1912 Nobel Prize in chemistry for it.

The method was taken over later by the enterprise BASF for ammonia production.

The Haber-Bosch-process serves to synthetically produce ammonia (NH3) from nitrogen and hydrogen.

The nitrogen needed for it is gathered from liquefied air. The N2 boils at -195.8 °C, 2 at -182.96 °C. Due to the different boiling temperatures of N2 and CO2 under enormously high energy can be separated through cooling.

Pure oxygen results as a quasi by-product. In order to make the elementary nitrogen reaction possible, however a high activation energy has to be invested in the form of heat and electricity.

Whereby the necessary hydrogen comes from water, or natural gas (NH3).

Haber and Bosch found, after many years of failed attempts, that the following four conditions for the equilibrium reaction between nitrogen and hydrogen- and thus for optimal ammonia production, are required.


A temperature of 550°C


A very high pressure from 150 to 250 bar.


A surplus of nitrogen (reference: The stoichiometric relationship with the reaction between nitrogen and hydrogen would be according to the theory 1:3, however in practice more nitrogen is added)


The presence of a catalyst.

Due to the high power requirement for atmospheric nitrogen fixing, the reactions needed for the separation of pure hydrogen, ammonia synthesis and the high temperatures necessary for the manufacturing process and pressures, account for about 1.4 % of the world's energy consumption, ie on the Haber-Bosch-process, whereby altogether approx. 100 million tons ammonia are produced annually.