Manufacture of Nitrogen-Containing Fertilizers

Ammonium sulfate is produced is produced as a byproduct in a number of processes both in and outside the chemical industry. In addition it is produced directly in small quantities by the neutralization of sulfuric acid with ammonia, concentrating the solution and crystallization  

Ammonium sulfate from ammonia and sulfuric acid in  

To obtain the coarse crystals required in agriculture, the reaction is carried out in special plants ( saturators ) in which the small crystals have a sufficiently long residence time in which to grow. 

70% Sulfuric acid is utilized with gaseous ammonia, the heat of neutralization then being sufficient to evaporate all the water. In a process operated in Japan, sulfuric acid is fed in at the top of a tower and gaseous ammonia at the bottom. The ammonium sulfate can be drawn off from the bottom, which requires no further drying. 

In the USA in 1993, 14% of the total production of ammonium sulfate was manufactured from ammonia and sulfuric acid. 

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Most of the nitric acid is utilized in the form of 50 to 70% acid for the manufacture of nitrogen-containing fertilizer, particularly ammonium nitrate. Ammonium nitrate is also used as an explosive e.g. in mining, due to its low explosion temperature (safety explosive). Other industrially important nitrates are sodium nitrate, a speciality fertilizer and oxidizing agent in the glass and enamel industries, and calcium and potassium nitrates, which are also used as fertilizers. Nitric acid is also utilized in the digestion of raw phosphate (Odda process, which is not operated in the USA, see Section 2.1.2.4) ... 

The demand for ammonia for the manufacture of nitrogen-containing fertilizers and other chemicals is huge. Today s industrial manufacture of more than 100 billion tons of ammonia per year is achieved by the Haber and Bosch process, discovered more than 80 years ago. In this process a Fe-based heterogeneous catalyst is used. 

This is the most important of the acids containing nitrogen and it is used in enormous quantities ( 14 billion lbs/yr). It is used in the manufacture of explosives, propellants, fertilizers, organic nitro compounds, dyes, plastics, and so on. It is a strong acid, because b = 2 in the formula (HO) XO/ and is a strong oxidizing agent. 

Nitric acid is used in the manufacture of fertilizers, dyes, drugs, and explosives. The Chemistry in Action essay on p. 849 describes a nitrogen-containing fertilizer that can be highly explosive. 

Nitric acid, HNO3, is a colorless, corrosive liquid used in the manufacture of nitrogen fertilizers and explosives. In an experiment to develop new explosives for mining operations, a sample containing 28.5 g of nitric acid was poured into a beaker. How many moles of HNO3 are there in this sample of nitric acid ... 

Ammonia is used for the manufacture of fertilizers or for the manufacture of other nitrogen-containing compounds used for fertilizer or, to a lesser extent, explosives, plastics, and fibers. Explosives made from ammonia are ammonium nitrate and (via nitric acid) the nitroglycerin used in dynamite. Plastics include (via urea) urea-formaldehyde and melamine-formaldehyde resins. Some ammonia ends up in fibers, since it is used to make hexameth-ylenediamine (HMDA), adipic acid, or caprolactam, all nylon precursors. 

Most of the ammonia that is produced is employed as fertilizer or used to manufacture other fertilizers, such as urea, ammonium sulfate, ammonium nitrate, or diammonium hydrogen phosphate. Ammonia is also used in the Solvay process, and it is a starting material for the manufacture of cyanides and nitriles (which are used to make polymers such as nylon and acrylics) as well as aromatic compounds containing nitrogen, such as pyridine and aniline. 

In tests made by TVA and IFDC of many other organic nitrogen-containing compounds as fertilizers, some proved readily available, some slowly available, some inert, and some toxic. Among those that showed promise as slow-release fertilizers were oxamide, glycouril, cyanuric acid, ammeline, and ammelide. For lack of an economical process, none of these materials has been manufactured commercially for fertilizer use. 

Ammonia X X X X Fertilizer and animal feed production manufacture of fibre, plastics, explosives, paper and rubber coolant metal processing starting production for many nitrogen-containing compounds cleaning agents food additive diuretic 311/2,3210,341, 351,3523,3529, 355, 38... 

In 2008, more than 95 percent of all the phosphate rock mined in the United States was used in the manufacture of fertilizer and animal feed supplements. Modern farmers use enormous amounts of synthetic (artificial) fertilizer on their crops. This synthetic fertilizer contains nitrogen, phosphorus, and potassium, the three elements critical to growing plants. These elements normally occur in the soil, but may not be present in large enough amounts. Adding them by means of synthetic fertilizer helps plants grow better. Most farmers add some form of synthetic fertilizer to their fields every year. This demand for synthetic fertilizers accounts for the major use of phosphorus compounds. 

Urea. H2NCONH2, is excreted in the urine as the chief nitrogen-containing end product of protein metabolism. It is synthesized on a large scale for use as a fertilizer and as a raw material in the manufacture of urea-formaldehyde plastics and of drugs. 

The commercial grade of [NH4][N03] contains 34% nitrogen. For fertilizers, it is manufactured in the form of pellets which are easily handled. Its high solubihty in water ensures efficient uptake by the soil. 

Production of animal glue is considered as environmentally friendly , since it involves conversion of unpleasant waste into useful products, but economic operation depends on satisfactory disposal of residues some of these are used as slow-release nitrogenous fertilizers. The mineral residue from bone glue production ( bone meal ) by thermal methods is used as a phosphate supplement in animal feed and fertilizers it is also calcined at 1000-1200 °C to produce calcined bone, used in the manufacture of bone china to provide strength and translucency. Animal glues and technical gelatins contain added preservatives and a proportion of non-protein materials, usually mucopolysaccharides and soluble inorganic salts. These impurities differ with the source of raw material. 

Ammonia is also used in the production of nitrogen fertilizer solutions that consist of ammonia, ammonium nitrate, urea, and water in various combinations. Some are pressure solutions and others are not. Nonpressure and low-pressure solutions are widely used for direct application to the soil. Pressure solutions containing free ammonia are used in the manufacture of high-analysis mixed fertilizers. 

Because wheat, rice, corn, and potatoes cannot perform the same feat as legumes, these plants depend on nitrogen-fbang bacteria in the soil. Soil bacteria convert NHg into nitrate ions, NO 3, the form of nitrogen that can be absorbed and used by plants. These plants also often need nitrogen fertilizers to supplement the work of the bacteria. Besides supplying nitrogen, fertilizers are manufactured to contain phosphorus, potassium, and trace minerals. 

Sulfuric acid has many uses but one of the largest uses is for fertilizer manufacture. Primary nutrients for plants are nitrogen, phosphorus and potassium. The major use of sulfuric acid in fertilizer manufacture is in the production of phosphoric acid, which in turn is used to produce phosphorus-containing fertilizers. 

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