Haber-Bosch ammonia synthesis


The Haber-Bosch Process. A modem ammonia plant performs two distinct functions. The more energy-demanding and complex function is the preparation and purification, from various feedstocks, of synthesis gas, known as syngas, which contains N2 and H2 in a 1 3 ratio. The second function is the catalytic conversion of syngas to ammonia (Fig. 2). In the years since commercial introduction in 1913, many process changes have been made in syngas production to lower costs and to give greater efficiencies.  [c.83]

These examples existed prior to Ostwald s definition (1), ie, before the nature of catalysis was weU understood. But in 1850 Wilhelmy (3) made the first measurements of kinetics of catalytic reactions in an investigation of sugar inversion catalyzed by mineral acids. In the years foUowing Ostwald s definition, just as the principles of chemical equiUbrium and kinetics were becoming known, the field of catalysis became more quantitative and developed rapidly. Kinetics of surface catalyzed reactions were measured by Bodenstein (4) just after the turn of the century. The defining work that set the stage for modem catalytic technology was the development of the ammonia (qv) synthesis process by Haber, Bosch, Mittasch, and co-workers at BASF in Germany, beginning ca 1908 (1,5).  [c.161]

Catalysts are discovered to meet processing needs and opportunities, but the discovery of a catalytic appHcation to take advantage of some newly discovered material almost never occurs. Catalyst development is largely a matter of trial and error testing. The methodology was defined by Haber, Bosch, and Mittasch in the development of the ammonia synthesis process. Catalyst developers benefit from an extensive and diverse Hterature and often can formulate good starting points in a search for candidate catalysts by learning what has been used successfully for similar reactions. Deeper insights, such as would arise from understanding of the mechanistic details of a catalytic cycle, are usually not attainable the exceptions to this rule largely pertain to molecular catalysis, usually reactions occurring in solution. Fundamental insights were valuable in guiding the development of the process for chiral hydrogenation and that for methanol carbonylation, among others, but it would be inappropriate to infer that understanding of the fundamental chemistry led to straightforward design of the catalysts. Indeed, the initial working hypothesis about the chiral hydrogenation turned out to be incorrect. The more comphcated processes of surface catalysis are for the most part only partially understood even when the processes are estabUshed and extensive after-the-fact research has been done. Creative research in catalyst discovery and development is usually the result of intuition and partial understanding combined with efficient testing and serendipity. Researchers who are repeatedly successful in finding new and improved catalysts seem to recognize needs and opportunities and notice significant exceptions to expected patterns and reason inductively by imperfect analogies.  [c.183]

In 1838, Frederic Kuhlmann discovered die formation of nitrogen oxide (NO) during die catalytic oxidation of ammonia. Wilhelm Ostwald developed die production mediods in 1902 and established die base for today s major commercial processes. However, industrial production began only after Haber and Bosch developed the synthesis of ammonia around 1916.  [c.86]

Ammonia and Hydrogen Production. The earliest route for manufacture of ammonia from nitrogen was the cyanamide process commercialized in Italy in 1906. In this process calcium carbide manufactured from coal was treated with nitrogen at 1000°C to form calcium cyanamide, CaCN2. The cyanamide was hydrolyzed with water affording ammonia and calcium carbonate. Production reached 140,000 t/yr in Germany in 1915, but this process was energy intensive and soon was displaced by the more efficient Bosch-Haber process. This process was developed by BASE and commercialized in 1913 and involves the high pressure reaction of nitrogen and hydrogen over an iron catalyst. Most of the world s hydrogen production is used in ammonia synthesis by the Bosch-Haber process. The hydrogen for ammonia synthesis generally is obtained from synthesis gas produced by steam  [c.164]

Essentially all the processes employed for ammonia synthesis are variations of the Haber-Bosch process developed in Germany from 1904—1913. One of the all-time breakthroughs of chemical technology, the synthesis process involves the catalytic reaction of a purified hydrogen—nitrogen mixture under high (14 to 70 MPa (2,030 to 10,150 psi)) pressure and temperature (400 to 600°C). The preferred catalysts consist of specially activated iron. The ammonia that forms is condensed by cooling with Hquefied ammonia the unreacted gases are recycled to the synthesis loop. In over 80% of the ammonia plants of the 1990s, the hydrogen—nitrogen feed mixture is prepared by a series of reactions known as steam reforming, for which the raw materials are steam, natural gas (methane), and air. Commercial plants have also been based on use of naphtha or coal (coke) as feedstock. AH facets of ammonia production are highly sophisticated engineering processes requiring both a high level of technical know-how and a large capital investment.  [c.216]

The first reports of nitric acid have been credited to Arab alchemists of the eighth century. By the Middle Ages it was referred to as aquafortis (strong water) or aqua valens (powerful water). From that time onward, nitric acid was produced primarily from saltpeter [7757-79-1] (potassium nitrate) and sulfuric acid. In the nineteenth century, Chilean saltpeter [7631-99-4] (sodium nitrate) from South America largely replaced potassium nitrate. However, at the beginning of the twentieth century newer manufacturing technologies were introduced. In Norway, where electricity was inexpensive, electric arc furnaces were used to make nitrogen oxides, and subsequendy nitric acid, direcdy from air. The commercial life of these furnaces was relatively brief and most were shut down by 1930. At about the same time, a different production method was being developed. In 1908, at Bochum, Germany, Ostwald piloted a 3-t per day nitric acid process based on the catalytic oxidation of ammonia with air. In 1913 the synthesis of ammonia from coal, air, and water was successfully demonstrated using the Haber-Bosch process. With a secure and economical supply of ammonia, ammonia oxidation became firmly estabhshed as an industrial route to nitric acid manufacture. Process developments continued and plant scale increased to commercial quantities in both Europe and the United States. The first full-size plant to be built in the United States was installed in 1917 by Chemical Constmction Company (Muscle Shoals, Alabama). The process operated at atmospheric pressure and used multiple ammonia oxidation converters. Since those early days, ammonia oxidation has become the basis of all commercial nitric acid production. There have been many advances in plant design leading to improved process performance and higher production capacities at increased operating pressures. The plants of the 1990s have single-train capacities up to 2000 t/d and operate at pressures up to 1.5 MPa (14.8 atm). More details on the history of nitric acid and development of the manufacturing process are available (1 4).  [c.38]

Ammonium compounds were produced ia the 1890s on a large scale as by-product ammonium sulfate [7783-20-2] from coke oven gas. Coke oven gas also provided the feedstock for the Haber-Bosch process, the first technology to synthesize ammonia directiy from elemental hydrogen and nitrogen. The first commercial Haber-Bosch iastaHation went on stream ia 1913 at a Badische Anilin and Soda Fabtik (BASF) faciUty ia Ludwigshafen-Oppau, Germany. It had a design capacity of 30 metric tons per day. The successful commercialization of this process not only produced first-of-a-kiad high temperature and pressure equipment designs but also resulted ia the promoted iron catalyst which is essentially stiU used for ammonia synthesis.  [c.339]

F. Haber s catalytic synthesis of NH3 developed in collaboration with C. Bosch into a large-scale industrial process by 1913. (Hater was awarded the 1918 Nobel Prize in Chemistry for the synthesis of ammonia from its elements Bosch shared the 1931 Nobel Prize for contributions to the invention and development of chemical high-pressure methods , the Hater synthesis of NH3 being the first high-pressure industrial process.)  [c.408]

The value of nitrogen compounds as an ingredient of mineral fertilizers was recognized ia 1840. Nitrogen is an essential element to plant growth and ammonia is the primary nitrogen source used ia fertilizers (qv). Until the early 1900s, the nitrogen source ia farm soils was entirely derived from natural sources from mineral resources such as CtuleaQ nitrates, from manure and the putrefaction of vegetable wastes and from ammonium sulfate from coal coking, seed meals, sewage sludges, and food processiag by-products. The synthesis of ammonia directiy from hydrogen [1333-74-0] (qv) and nitrogen [7727-37-9] (qv) on a commercial scale was pioneered by Haber and Bosch ia 1913, for which they were awarded Nobel prizes. Further developments ia economical, large scale ammonia production for fertilizers have made a significant impact on iacreases ia the world s food supply.  [c.335]


See pages that mention the term Haber-Bosch ammonia synthesis : [c.73]   
Chemistry of the elements (1998) -- [ c.408 , c.409 ]