Ostwald process manufacture

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 ... 

NH3 + 5 02 > 4 NO + 6 H20 Pt and Rh First step in the Ostwald process for synthesis of nitric acid HN03 Manufacture of explosives, fertilizers, plastics, dyes, lacquers... 

Molecular nitrogen (N2) is unreactive because of its strong N=N triple bond. Nitrogen exhibits all oxidation states between —3 and +5. Nitric acid is manufactured by the Ostwald process. 

EnviNOx Two related processes for removing N20 and NOx from the tailgases from nitric acid manufacture by the Ostwald process. Both variants use two beds of two zeolite catalysts modified with iron. The first variant is for gases hotter than 425°C and involves injecting ammonia between the beds. The second variant, for gases cooler than 425°C, injects ammonia before the first bed and a volatile hydrocarbon between the beds. Developed by Uhde in association with Agrolinz Melamine International. The first variant was installed in Linz, Austria, in 2003. The second variant was installed in Egypt in 2007. The catalysts are supplied by Sud-Chemie. 

Fig. 1.4-5. Schema of the Ostwald process for the manufacture of nitric acid.

Nitro acid, 17-31, for guncotton, 93 for I nitroglycerine, 88 manufacture from ammonia, 28, 29 manufacture from atmosphere, 21-28 manufacture from Chile saltpetre, 17-20 properties of 29, 30 Ostwald process, 28, 29 red fuming, 30 spe cific gravity of, 30 S statistics, 31 transport of, 30 vacuum process, 20 Nitric organism, 5... 

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 Other now outdated processes include the reaction of sodium nitrate with sulfuric acid and direct synthesis from N2 and 02 by the arc process at temperatures in excess of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. 

Nitric acid (HNO3) is a very important strong acid manufactured by the Ostwald process... 

Nitric acid is an important industrial chemical (see Box 15.8) and is manufactured on a large scale in the Ostwald process, which is closely tied to NH3 production in the Haber-Bosch... 

Ostwald process The manufacture of nitric acid by the catalytic oxidation of ammonia. In the first step of the process, compressed air and ammonia react (at 1,472°F [800 C] in the presence of a platinum gauze catalyst) to give nitrogen monoxide and water. 

Ammonia production in the world is presently as large as 110 million tonnes per year. The product is stored as a liquid at a pressure of 100 atm (10.1 MPa) and a temperature of -35.5°C. Ammonia is the base material for the manufacture of nitrogen oxides and various industrial products. Nitrogen oxides have a number of appHca-tions. NjO is used in medicine, as it has anesthetic properties (laughing gas). is used as an oxidizer in rocket fuel. From ammonia, nitric add is manufactured by oxidation with air at about 800°C. Different types of catalysts, e.g. platinum, may be used. NO, formed in the oxidation, is reacted with water to HNOj and NO. The technique is called the Ostwald process. 

Nitric acid is an important industrial chemical (Box 15.8) and is manufactured on a large scale in the Ostwald process, which is closely tied to NH3 production in the Haber-Bosch process. The first step is the oxidation of NH3 to NO (eq. 15.23). After cooling, NO is mixed with air and absorbed in a countercurrent of water. The reactions involved are summarized in scheme 15.116. This produces HNO3 in a concentration of 60% by weight and it can be concentrated to 68% by distillation. 

The first step in the Ostwald process for manufacturing nitric acid is the reaction between ammonia and oxygen described by the equation 4 NH3 + 5 O2 4 NO + 6 HjO. Use this equation to answer all parts of this question. 

The first step in the manufacture of nitric acid by the Ostwald process is the reaction of ammonia gas with oxygen, producing nitrogen oxide and steam. The reaction mixture contains 7.60 g of ammonia and 10.00 g of oxygen. After the reaction is complete, 6.22 g of nitrogen oxide are obtained. 

Pritz Haber s successful synthesis of ammonia a few years before the First World War had a profound impact on world history. Nitric acid and nitrates are essential in the manufacture of fertilizers and explosives. Haber s synthesis of ammonia without impurities made it possible to manufacture nitric acid by the Ostwald process. Unfortunately the first major application of ammonia production was manufacture of explosives which prolonged the war. 

Nitric acid is produced industrially by the Ostwald process. The majority of HNO3 is used in the manufacture of fertilizers. 

In addition to fertilizer production, one of the most important uses for ammonia is in the manufacture of nitric acid by the Ostwald process, as discussed earlier in this Book. In essence, ammonia is oxidized over a catalyst to oxides of nitrogen, which are dissolved in water to form a concentrated solution of the acid. From a purely practical standpoint, the initial oxidation step is worth a closer look. 

The modem process for manufacturing nitric acid depends on the catalytic oxidation of NH3 over heated Pt to give NO in preference to other thermodynamically more favour products (p. 423). The reaction was first systematically studied in 1901 by W. Ostwald (Nobel Prize 1909) and by 1908 a commercial plant near Bochum. Germany, was producing 3 tonnes/day. However, significant expansion in production depended on the economical availability of synthetic ammonia by the Haber-Bosch process (p. 421). The reactions occurring, and the enthalpy changes per mole of N atoms at 25 C are ... 

Nitric acid (HNO ) is an important commercial chemical and was manufactured commercially to produce fertilizers and explosives as well as plastics and many other products. In 1902 a German chemist, WiUrehn Ostwald (1853—1932), developed a process wherein at high temperatures he used platinum catalysts to convert ammonia into nitric acid. When nitric acid is reacted with glycerol, the result is nitroglycerine—an unstable explosive unless dissolved in inert material, such as clay. It can then be stabihzed as dynamite. 

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. 

The importance of catalysts in chemical reactions cannot be overestimated. In the destruction of ozone previously mentioned, chlorine serves as a catalyst. Because of its detrimental effect to the environment, CFCs and other chlorine compounds have been banned internationally. Nearly every industrial chemical process is associated with numerous catalysts. These catalysts make the reactions commercially feasible, and chemists are continually searching for new catalysts. Some examples of important catalysts include iron, potassium oxide, and aluminum oxide in the Haber process to manufacture ammonia platinum and rhodium in the Ostwald synthesis of nitric... 

Catalysis refers to the phenomenon by which the rate of a chemical reaction is accelerated by a snbstance (the catalyst) not appreciably consnmed in the process. The term catalysis was coined by Berzelins in 1835 and scientifically defined by Ostwald in 1895, but applications based on catalysis can be traced back to thousands of years ago with the discovery of fermentation to produce wine and beer. Nowadays, catalysts are used in 80% of all chemical industrial processes, and create annual global sales of about 1500 billion dollars and contribute directly or indirectly to approximately 35% of the world s GDP. Catalysis is central to a myriad of applications, including the manufacture of commodity, fine, specialty, petro-, and agro- chemicals as well as the production of pharmaceuticals, cosmetics, foods, and polymers. Catalysis is also an important component in new processes for the generation of clean energy, and in the protection of the enviromnent both by abating environmental pollutants and by providing alternative cleaner chemical synthetic procedures. 

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