The Haber process, named after Fritz Haber, is an industrial process in which ammonia is manufactured by direct combination of its elements, nitrogen and hydrogen. The reaction is carried out at 400 to 500°C and at 200 atmospheres. The two gases (nitrogen and hydrogen), 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.
See also: Ammonia.