1. Fundamental aspects of the synthesis reaction

The history of ammonia synthesis goes back to Haber's discovery in 1909 of the catalytic effect of iron on direct synthesis from hydrogen and nitrogen. Under Bosch's impetus, the process was soon industrialized. As early as 1920, a 50 t/d reactor was commissioned by BASF in Ludwigshafen [1] .

Today, unit capacities of up to 1,800 t/d are in operation, and world production is approaching 140 Mt per year (production in France was around 1.6 Mt in 1997).