HaberBosch

The Haber-Bosch process is an industrial method for synthesizing ammonia (NH3) from nitrogen (N2) and hydrogen (H2) using an iron-based catalyst under high pressure and temperature. It is named after Fritz Haber, who developed the chemical reaction, and Carl Bosch, who scaled it for industrial production at BASF in the early 20th century. The process converts N2 and H2 to NH3 via N2 + 3 H2 ⇌ 2 NH3. It is exothermic; higher pressure favors ammonia formation, but higher temperature increases the reaction rate. Modern plants operate at roughly 150–350 atmospheres and 400–500 degrees Celsius to balance conversion, catalyst life, and equipment costs.

Hydrogen is typically produced from natural gas by steam reforming and the water-gas shift reaction, while nitrogen is obtained from air by separation. The gas mixture is compressed, circulated over an iron-based catalyst with promoters such as potassium and aluminum oxide, and cooled to condense ammonia, which is separated from unreacted gases that are recycled into the reactor.

The Haber-Bosch process enables large-scale production of ammonia, a key feedstock for fertilizers such as urea and ammonium nitrate and for other chemicals. Its development is considered pivotal for modern agriculture, supporting the Green Revolution by providing a scalable source of fixed nitrogen. However, the process is energy-intensive and contributes to CO2 emissions when hydrogen is produced from fossil fuels; ongoing research seeks greener routes, including renewable-energy–driven hydrogen and new catalysts.

See also: Haber process; ammonia synthesis.