The Haber-Bosch Synthesis Reactor

The ammonia synthesis reaction is exothermic, but as a result of the low conversion heat loss from the small early reactor exceeded the heat of reaction. 

Therefore, additional heat had to be supplied to the catalyst bed and this was done in a number of ways  

A reactor, producing 20 tons.day of ammonia weighed about 70 tonnes, was 12 m long, and held a basket of 80 cm internal diameter. It took about 3 days to change a deactivated catalyst and restart operation. In those days, in order to increase production, typical ammonia plants operated with several small reactors rather than a single large one. 

The production of ammonia during the early 1900s stimulated the increasing use of industrial catalysts. Development of the synthesis catalyst set a pattern for all other catalysts subsequently used in chemical and refining processes. 

Theoretical and experimental effort had shown that the process was feasible. This was followed by the development of practical equipment and full-scale operation. A relatively cheap and reliable catalyst was thoroughly tested and produced economically in what were then large volumes. Finally, both the process and catalyst were gradually improved as the scale of operation expanded. 

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