The industrial production of urea using a high-pressure process goes back to Carl Bosch and Wilhelm Meiser. In 1922, BASF put the first production plant into operation where in a high-pressure reactor in a first step at 150 bar, ammonia and carbon dioxide formed ammonium carbamate (NH4CO2NH2) in an -117 kJ / mol exothermic reaction:
2NH3 + CO2 → NH4CO2NH2
Ammonium carbamate further reacts in an endothermic reaction to urea and water:
NH4CO2NH2 → NH2CONH2 + H2O
In addition to CO2, nitrogen is also used for inerting purposes.