The Successful Synthesis of Ammonia from Atmospheric Nitrogen

THE SUCCESSFUL SYNTHESIS OF AMMONIA FROM ATMOSPHERIC NITROGEN  

The successful demonstration of ammonia synthesis was reported in March, 1910 at a meeting in Karlsruhe/ It generated a sensational response as the new process to obtain bread from the air.  

The industrial development of ammonia synthesis was started in BASF immediately after that day in Karlsruhe, and Bosch was made responsible for the whole project. Despite the success of the feasibility study in Karlsruhe there were still many problems to be solved before a large-scale manufacturing process could be designed and built. 

In the first instance, substantially better catalysts were required for the synthesis stage. As mentioned above, active and stable catalysts allow the synthesis reaction to take place at lower pressures and temperatures. It was, accordingly, of fundamental importance to discover good catalysts which were cheaper and more stable than osmium and uranium, since both were difficult to obtain and presented handling problems. 

Solutions to all these problems presented considerable difficulties. Bosch and his co-workers had to overcome these hurdles, one at a time, in the embryo period of these emerging technologies. However, they worked as a powerful team, showing a great problem-solving capability. To solve the catalyst problem, they first turned to iron. This was known to be an effective catalyst for the decomposition of ammonia and Ostwald, Nemst, and Haber had all used iron as the catalyst in their early experiments. Mittasch and his co-workers noted in their experiments that the activity of iron catalysts was markedly influenced by the presence of a small amount of impurities in it. Consequently, they started to study multicomponent catalysts, by addition of other compounds to pure iron catalysts.  

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