The most popular catalysts are based on iron promoted with K 2O, CaO, SiO 2, and Al 2O 3.ĭuring the interwar years, alternative processes were developed, most notably the Casale process, Claude process, and the Mont-Cenis process developed by Friedrich Uhde Ingenieurbüro. ![]() A major contributor to the elucidation of this catalysis was Gerhard Ertl. In 1909, BASF researcher Alwin Mittasch discovered a much less expensive iron-based catalyst that is still used. Haber noted uranium was almost as effective and easier to obtain than osmium. The original Haber–Bosch reaction chambers used osmium as the catalyst, but it was available in extremely small quantities. Synthetic ammonia from the Haber process was used for the production of nitric acid, a precursor to the nitrates used in explosives. ![]() Germany had no such resources, so the Haber process proved essential to the German war effort. India had large supplies too, but it was also controlled by the British. The Allies had access to large deposits of sodium nitrate in Chile (Chile saltpetre) controlled by British companies. During World War I, the production of munitions required large amounts of nitrate. Īmmonia was first manufactured using the Haber process on an industrial scale in 1913 in BASF's Oppau plant in Germany, reaching 20 tonnes/day in 1914. Haber and Bosch were later awarded Nobel Prizes, in 19 respectively, for their work in overcoming the chemical and engineering problems of large-scale, continuous-flow, high-pressure technology. The process was purchased by the German chemical company BASF, which assigned Carl Bosch the task of scaling up Haber's tabletop machine to industrial scale. They demonstrated their process in the summer of 1909 by producing ammonia from the air, drop by drop, at the rate of about 125 mL (4 US fl oz) per hour. Haber, with his assistant Robert Le Rossignol, developed the high-pressure devices and catalysts needed to demonstrate the Haber process at a laboratory scale. Although atmospheric nitrogen (N 2) is abundant, comprising ~78% of the air, it is exceptionally stable and does not readily react with other chemicals. At the beginning of the 20th century these reserves were thought insufficient to satisfy future demands, and research into new potential sources of ammonia increased. The main source was mining niter deposits and guano from tropical islands. N 2 + 3 H 2 ⟶ 2 NH 3 Δ H ∘ = − 91.8 kJ/mol īefore the development of the Haber process, it had been difficult to produce ammonia on an industrial scale, because earlier methods, such as the Birkeland–Eyde process and the Frank–Caro process, were too inefficient.ĭuring the 19th century, the demand for nitrates and ammonia for use as fertilizers and industrial feedstocks rapidly increased. Hydrogen is produced via steam reforming, followed by an iterative closed cycle to react hydrogen with nitrogen to produce ammonia. It decreases entropy, complicating the process. ![]() it releases energy), meaning that the reaction is favoured at lower temperatures and higher pressures. ![]() This reaction is slightly exothermic (i.e. The process converts atmospheric nitrogen (N 2) to ammonia (NH 3) by a reaction with hydrogen (H 2) using a metal catalyst under high temperatures and pressures. It is named after its inventors, the German chemists: Fritz Haber and Carl Bosch, who developed it in the first decade of the 20th century. The Haber process, also called the Haber–Bosch process, is the main industrial procedure for the production of ammonia.
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