The Haber–Bosch processCatalystsHaber Bosch process ofConverters, ammoniaBASF BASFCatalystsBASF whenConverters, ammoniaBASF introduced in 1913 was achieved by a team of chemists and engineers headed by Carl Bosch[aut]Bosch, Carl. Less than a decade later, Luigi Casale[aut]Casale, Luigi almost single-handedly introduced a slew of new features in order to design a more effective variant for synthesizing ammonia from its elements. However, the type of challenges faced by both Carl Bosch[aut]Bosch, Carl and Luigi CasaleHydrogen, processeselectrolysisCasale were not unalike. They included: pure and cheap to produce nitrogenFertilizersnitrogen and hydrogen, the availability of compressors, the formulation of catalystsCatalysts, and materials of constructionBadische Anilin & Soda-Fabrik (BASF)ammonia, manufacture of. Economic sources of hydrogen, the main input, were determined by the cost of electricity, in the case of electrolysisHydrogen, processeselectrolysis, or the availability of fossil fuels. The larger factories relied on water gasHydrogen, processeswater gas, made from coal. By the early 1930s, coking oven gas processes were also important, particularly in Europe. Investigations into the use of natural gas led to the early development of catalytic steam methane reformingReforming, development ofmethane.