Ammonia oxidation Ostwald process

Currently, nitric acid is manufactured exclusively by catalytic oxidation of ammonia. Platinum or platinum-rhodium is an effective catalyst of this oxidation (Ostwald process). Three basic steps in such ammonia oxidation process are (1) oxidation of ammonia to form nitric oxide ... 

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. 

H.20 The first stage in the production of nitric acid by the Ostwald process is the reaction of ammonia gas with oxygen gas, producing nitric oxide gas, NO, and liquid water. The nitric oxide further reacts with oxygen to produce nitrogen dioxide gas, which, when dissolved in water, produces nitric acid and nitric oxide. Write the three balanced equations that lead to the production of nitric acid. 

Ammonia is also the starting material for the production of nitric acid, and the first step is oxidation of ammonia by the Ostwald process. 

In the early 1900s, it was discovered that ammonia could be oxidized in the presence of a platinum catalyst (the Ostwald process). 

One of the steps in the Ostwald process for the production of nitric acid involves the oxidation of ammonia. 

Platinum also is used extensively as a catalyst in hydrogenation, dehydrogenation, oxidation, isomerization, carbonylation, and hydrocracking. Also, it is used in organic synthesis and petroleum refining. Like palladium, platinum also exhibits remarkable abdity to absorb hydrogen. An important application of platinum is in the catalytic oxidation of ammonia in Ostwald s process in the manufacture of nitric acid. Platinum is installed in the catalytic converters in automobile engines for pollution control. 

Ostwald process The production of nitric acid by the catalytic oxidation of ammonia, overall order The sum of the powers to which individual concentrations are raised in the rate law of a reaction. Example If the rate = [S02][S03]" l/2, then the overall order is f. 

PROBLEM 8.16 Use the information in Table 8.2 to calculate AH° (in kilojoules) for the reaction of ammonia with 02 to yield nitric oxide (NO) and H20(g)/ a steP m the Ostwald process for the commercial production of nitric acid. 

In the first step of the Ostwald process for the synthesis of nitric acid, ammonia is converted to nitric oxide by the high-temperature reaction... 

Nitric acid is produced industrially by the multistep Ostwald process, which involves (1) air oxidation of ammonia to nitric oxide at about 850°C over a platinum-rhodium catalyst, (2) rapid oxidation of the nitric oxide to nitrogen dioxide, and (3) disproportionation of N02 in water ... 

Researchers returned to the oxidation of ammonia in air, (recorded as early as 1798) in an effort to improve production economics. In 1901 Wilhelm Ostwald had first achieved the catalytic oxidation of ammonia over a platinum catalyst. The gaseous nitrogen oxides produced could be easily cooled and dissolved in water to produce a solution of nitric acid. This achievement began the search for an economic process route. By 1908 the first commercial facility for production of nitric acid, using this new catalytic oxidation process, was commissioned near Bochum in Germany. The Haber-Bosch ammonia synthesis process came into operation in 1913, leading to the continued development and assured future of the ammonia oxidation process for the production of nitric acid. 

The Ostwald process is the basis for the modem family of processes that make nitric acid by the catalytic oxidation of ammonia. Wilhelm Ostwald, a German physical chemist, discovered it in 1900. The process was used by Germany during World War I to make explosives after the Allied blockade cut off the regular German supply of nitrites from Chile and other places96. 

In the Ostwald process ammonia is catalytically oxidized in a heterogeneous reaction. The key steps in the process are 1) Oxidation of ammonia to nitric oxide (NO), 2) Oxidation of NO to nitrogen dioxide (NO2) and 3) Absorption ofN02 in water to produce nitric acid. These steps are summarized in the following sections91,97. 

The major deposits of alkali nitrates found in Chile were vital for making nitric acid, which is necessary to prepare almost all types of explosives and propellants. Of course, nitric acid is now obtained by the catalytic oxidation of ammonia by the Ostwald process (see Chapter 12). 

Nitric acid is produced commercially by the Ostwald process. In the first step ammonia is oxidized to nitric oxide ... 

Ostwald process a commercial process for producing nitric acid by the oxidation of ammonia. (19.2)... 

Nitric acid is currently almost exclusively produced by the catalytic oxidation of ammonia using the Ostwald process (1902). The reaction of sodium nitrate (Chile niter, the only nitrate occurring naturally in large quantities) with sulfuric acid, operated at the turn of the century, has not been economic since the emergence of the Haber-Bosch ammonia synthesis process shortly before World War 1. The... 

Ostwald process An industrial process that produces oxide and nitric acid from ammonia and oxygen. 

Present-day nitric acid production is almost entirely via the oxidation of ammonia and absorption of the oxidation products in water. The chemistry of this process was proven experimentally by Kuhlmann in 1839, but had to wait for the development of an economical route to ammonia before it could become commercially significant [38]. Ostwald, working in Germany in about 1900, reexamined and extended Kuhlmann s data and established the proper conditions required for the ammonia oxidation step. Very shortly after this plants operating on these principles were constructed both in Germany and the U.S. Since 1980, 3-5 million metric tonnes of nitric acid (100% basis) have been produced annually in Germany, and 7-9 million tonnes in the U.S. (Table 11.7). 

Most of the modem manufacture of nitric acid is done by the catalytic oxidation of ammonia (Ostwald process). Other now outdated processes include the reaction of sodium nitrate with sulfuric acid and direct synthesis from N2 and 02 by the arc process at temperatures in excess of 2,000°C. Once cheap ammonia became available these processes were no longer economical. 

The chemical nature and composition of nitric acid were first determined in 1784 by the English chemist and physicist Henry Cavendish (1731-1810). Cavendish applied an electric spark to moist air and found that a new compound-nitric acid-was formed. Cavendish was later able to determine the acid s chemical and physical properties and its chemical composition. The method of preparation most commonly used for nitric acid today was one invented in 1901 by the Russian-born German chemist Friedrich Wilhelm Ostwald (1853-1932). The Ostwald process involves the oxidation of ammonia over a catalyst of platinum or a platinum-rhodium mixture. 

Although several methods for the preparation of nitric acid are theoretically available, only one finds much commercial use the direct oxidation of ammonia, an updated and improved version of the traditional Ostwald process. In this method, ammonia is heated and reacted with air over a catalyst, most commonly a mixture of rhodium and platinum metals. That reaction results in the formation of nitric oxide (NO), which is then converted to nitrogen dioxide (N02). The nitrogen dioxide reacts with water to form nitric acid. 

At 1000°C, ammonia gas, NH3(g), reacts with oxygen gas to form gaseous nitric oxide, NO(g), and water vapor. This reaction is the first step in the commercial production of nitric acid by the Ostwald process. Balance the equation for this reaction. 

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