Haber-Bosch process

Industrial process in which ammonia is manufactured by direct combination of its elements, nitrogen and hydrogen. The reaction is carried out at 752–932°F/400–500°C and at a pressure of 200 bar. The two gases, in the proportions of 1:3 by volume, are passed over a catalyst of finely divided iron.

Around 10% of the reactants combine, and the unused gases are recycled. The ammonia is separated by either dissolving in water or cooling to liquid form.

The equation

N₂ + 3H₂ « 2NH₃

predicts that the volume of the gas mix should be reduced by half if the reactants were completely converted to ammonia. Thus, following Le Chatelier's principle, high pressure can be used to shift the equilibrium to the right hand side.