It operates under conditions of high temperature 400–500 °C and pressure 200–250 bar, and its production has a huge carbon footprint. The H2 precursor, usually obtained by steam reforming of methane, also has a very large carbon footprint. Notably, the entire energy required to prepare the reagents and to operate the Haber-Bosch process amounts to 1–3% of the global energy supply. In stark contrast, in the natural world, plants and bacteria have been producing NH3 from N2 and solvated protons under ambient conditions, enabled by the FeMo cofactor of the metalloenzyme nitrogenase (N2 + 6H+ 6e-→2NH3). Inspired by this biological nitrogen fixation process, intensive efforts have been devoted to finding ways to mimic the process under similarly mild conditions.
The Haber-Bosch process uses a catalyst or container made of iron or ruthenium with an inside temperature of over 800?F (426?C) and a pressure of around 200 atmospheres to force nitrogen and hydrogen together. The elements then move out of the catalyst and into industrial reactors where the elements are eventually converted into fluid ammonia (Rae-Dupree, 2011). The fluid ammonia is then used to create fertilizers.