Ammonia, and ammonium nitrate

Free energies of formation suggest that ammonia and ammonium nitrate could be produced spontaneously in... 

Ammonium nitrate prepared from ammonia obtained by the dry distillation of coal should not be used as component of any explosive material because of the ammonium thiocyanate and pyridine present in it (the latter as nitrate). When the ammonia liquor from dry distillation of coal was the sole source af ammonia and ammonium nitrate, decomposition of mixtures containing ammonium nitrate with TNT (amatols), was brought about at the melting point TNT reacted with ammonium thiocyanate or with pyridine nitrate and evolved gaseous products. Minute traces of these impurities were sufficient to cause abundant gas evolution to develop during the fusion, pouring, and cooling of amatol. 

The steam production section comprising the steam superheater and waste-heat boiler is designed to lower the reaction-gas temperature from 645°C to 280°C (further oxidation in these vessels will also continue to produce reaction heat). Steam of sufficient quality is to be produced for export to the adjacent ammonia and ammonium nitrate plants. Medium-pressure steam (at 380°C and 4000 kPa) is preferred. 

Hoffmann and co-workers49 160 first successfully isolated 1,2-dihydropyrim-idines 93 from a condensation of the dimethylacetal of acetoacetic aldehyde with different carbonyl-containing compounds in the presence of ammonia and ammonium nitrate [Eq. (32)]. 

In practice, the ammonolysis is carried out in the presence of ammonium salts—preferably ammonium nitrate—and the comparatively stable guanidine nitrate is formed. Such a technique is employed to prevent the relatively active guanidine from combining with unreacted cyanamide to form melamine. The reaction is carried out by heating calcium cyanamide, cyanamide, or dicyandiamide with ammonia and ammonium nitrate for 2 hr at 160°C under autogenic pressure. During the course of the reaction, dicyandiamide is formed from cyanamide in the presence of ammonia and, in all probability, is the primary product. The monomeric reaction is... 

C. W. Keitel et al. give another bath formula cis-dinitrodiam-mineplatinum is dissolved in ammonia, and ammonium nitrate and sodium nitrite are added to improve the conductivity of the bath. 

From the reaction and evaporation systems steam containing ammonia and ammonium nitrate these are in small quantities and treated in the scrubbing system. Scrubbing waters are recycled to the reaction/evaporation system. 

Other chemical exchange reactions that have been used for the fractionation of nitrogen isotopes include ammonia and ammonium nitrate solution [45], ammonia and ammonium carbonate [46], and ammonia and its complexes with aliphatic alcohols [47]. 

The principal use for urea is as fertilizer, with over 80 percent of all production being consumed for this purpose. Urea is used as a solid fertilizer and also in solutions in combination with ammonia and ammonium nitrate. The latter commercial product is known as UAN. Continued growth is expected because the solution can be handled as if it were water, in contrast to the handling required for anhydrous ammonia. 

Ammonia from coal gasification has been used for fertilizer production at Sasol since the beginning of operations in 1955. In 1964 a dedicated coal-based ammonia synthesis plant was brought on stream. This plant has now been deactivated, and is being replaced with a new faciUty with three times the production capacity. Nitric acid is produced by oxidation and is converted with additional ammonia into ammonium nitrate fertilizers. The products are marketed either as a Hquid or in a soHd form known as Limestone Ammonium Nitrate. Also, two types of explosives are produced from ammonium nitrate. The first is a mixture of fuel oil and porous ammonium nitrate granules. The second type is produced by emulsifying small droplets of ammonium nitrate solution in oil. 

Pipeline systems for transporting anhydrous ammonia that are urea and ammonium nitrate (UAN) and LNG compatible, exist in Europe, Mexico, and the Soviet Union. Export-oriented ammonia producing countries utilize huge ocean-going tankers that contain up to 50,000 t for distribution of ammonia. Co-shipment in refrigerated LNG tankers is usuaky done. 

Markets. Industrial use of ammonia varies according to region. Eor example, industrial usage represents 20% of the ammonia production in the United States and Western Europe, 10% in the USSR, 1—10% in Asia, and 5% in Latin America and North Africa (79). Fertiliser ammonia consumed domestically in most countries is converted to straight or compound fertilisers such as urea, ammonium nitrate, diammonium phosphate, and various grades of mixed fertilisers. However, almost 29% of ammonia nitrogen in the United States is consumed as direct appHcation material. The use of nitrogen solution such as urea and ammonium nitrate (UAN) has also become popular in the United States and the USSR. 

Nitrogen solutions consist of fertilizer product combinations, eg, ammonium nitrate —ammonia, urea—ammonium nitrate—ammonia, urea—ammonium nitrate, and urea—ammonia solutions. Mixed fertilizers cover a broad range and can be loosely defined as fertilizers which contain chemically mixed nitrogen, phosphoms, and potassium (N—P—K). Examples are ammonium phosphate—potash mixtures and ammonium phosphate nitrates. 

Nitric acid is a strong, monobasic acid. It reacts readily with alkalies, oxides, and basic materials, forming salts. The reaction with ammonia, forming ammonium nitrate, for use as a fertilizer, is by far the largest single industrial outlet for nitric acid... 

Pyridines are traditionally prepared using the Hantzsch reaction, a condensation between 2 mol of a 6-ketoester, 1 mol of an aldehyde and 1 mol of ammonia. The product of this reaction is a 1,4-dihydropyridine which can be further oxidized to the corresponding pyridine compound (as 155 in Scheme 54). A first report described the Hantzsch reaction carried out under microwave irradiation on Bentonite clay and ammonium nitrate as ammonia... 

All of these species are very soluble in a rain or cloud drop and are an important source of atmospheric aerosols. For ammonia and ammonium, the condensed phases (I and s) represent approximately two-thirds of the total atmospheric burden, whereas for nitric acid and nitrates, about two-thirds is in the gas phase (Soderlund and Svensson, 1976). 

Ammonia G A Coal distillation (coke ovens) Nitric acid production Urea and ammonium nitrate works... 

N2 + 3 H2 2 NH3 A Gj-eaction — " 32.8 kJ Figure 14-17 shows other spontaneous reactions that lead from ammonia to nitric acid, urea, and ammonium nitrate. 

According to an O.S. amendment sheet, the procedure as described [1] is dangerous because the reaction mixture (dicyanodiamide and ammonium nitrate) is similar in composition to commercial blasting explosives. This probably also applies to similar earlier preparations [2]. An earlier procedure which involved heating ammonium thiocyanate, lead nitrate and ammonia demolished a 50 bar autoclave [3], TGA and DTA studies show that air is not involved in the thermal decomposition [4], Explosive properties of the nitrate are detailed [5], An improved process involves catalytic conversion at 90-200°C of a molten mixture of urea and ammonium nitrate to give 92% conversion (on urea) of guanidinium nitrate, recovered by crystallisation. Hazards of alternative processes are listed [6],... 

Similarly to melamine hydrobromide, in the second step of weight loss (370-450 0, Figure 8), IR data show that melam nitrate evolves further ammonium nit rate,ammonia and melamine nitrate giving melon which decomposes completely to volatile products above 500 C. The degradation scheme is then ... 

Ebara [Electron beam ammonia reaction] A dry process for removing sulfur and nitrogen oxides from flue-gas. A beam of high energy electrons is injected into the gas, to which a stoichiometric quantity of ammonia has been added. The product, a mixture of ammonium sulfate and ammonium nitrate, is collected downstream by an electrostatic precipitator or a bag filter. Developed by Ebara Corporation, Japan, and piloted in Indianapolis in 1986. 

Later workers (489) have postulated the existence of intermediate biguanide in the interaction of cyanoguanidine and ammonium nitrate in liquid ammonia (at relatively high temperatures). The reaction is thus thought to adopt the same reaction path as that of the analogous fusion, but positive evidence for this view is difficult to obtain, because of the rapidity with which all postulated intermediates are onverted into guanidine salts. 

Table 4.1 gives the use profile for ammonia. It can be applied directly for fertilizer or made into other nitrogen-containing compounds used for fertilizer such as urea, ammonium nitrate, ammonium phosphate, ammonium sulfate, and nitric acid. Overall approximately 80% of ammonia has an end use as fertilizer. Explosives, a second important end use, made from ammonia are ammonium nitrate and, via nitric acid, the nitroglycerin used in dynamite. Chemical intermediates include acrylonitrile and caprolactam, which eventually go into fibers. 

Nitric and sulfuric acids readily dissolve in water drops, lowering the vapor pressure of the water and stabilizing the smog aerosols. Ammonia from animal feedlots also dissolves in these drops, creating ammonium sulfate and ammonium nitrate. 

The retarding action of ammonia has also been observed in the decomposition of a number of ammonium salts, eg ammonium perchlorate (NH4CIO4) and ammonium nitrate (NH4N03) (Ref 10) ... 

Diammino-silver nitrate forms glistening rhombic or prismatic crystals which blacken on exposure to light. It is fairly stable, and may be heated to 100° C. without loss of ammonia. Further heating causes it to decompose, and finally to melt with evolution of nitrogen and ammonia, leaving a residue of metallic silver and ammonium nitrate. It is soluble in water, but partial dissociation takes place so that the solution is alkaline in reaction, and it therefore yields a precipitate of silver chloride and soluble chlorides. Certain of the metals—for example, zinc, cadmium, and copper—quickly reduce the ammine in solution to metallic silver. 

Agriculture therefore depends on there being a sufficient supply of inorganic nutrients to plants. Cereals, vegetables, fruit-bearing trees or plants, and animal fodder require bioavailable nutrients, that is, nutrients in forms that they can use. Since intensive agriculture depletes many natural nutrients, synthetic nutrients (fertilizers) must be supplied.1-7 In particular, we need to fix the inert N2 of the atmosphere as soluble, reactive compounds such as nitrates, ammonia, and ammonium salts. Other major fertilizer components are sulfate, potassium, and phosphate ions. It may also be necessary to provide trace nutrients, such as cobalt compounds, or to remove excess soil acidity by treatment with lime (CaO). World fertilizer demand in the year 2001 is expected to be about 1.5 x 10s metric tons N, 7.6 x 107 metric tons P2O5, and 6.7 x 107 metric tons K2O these projections represent an... 

When organic matter decays, say, in the soil of cattle yards and stables, ammonia and ammonium compounds are produced by the action of certain bacteria. If the soil be fairly dry, but not too dry, a white scum appears on the exposed surface. The scum is made up of small crystals of potassium nitrate and, after a time, if the soil be extracted with water and strained, the liquid, on evaporation, furnishes yellowish-brown crystals of crude nitre. The crude nitre can be purified by resolution and crystallization. The white efflorescence sometimes seen on the walls of stables, etc., is sometimes, though not always, due to the formation of nitrates in this way. 

E. Rammann noted that a little ammonium nitrate is formed during the reduction of a soln. of ferric nitrate by metallic iron whereby ferrosoferric oxide is precipitated, and ammonium nitrate appears in the soln. E. W. von Siemens and J. G. Halske patented a process in which a mixture of well-dried oxygen, nitrogen, and ammonia... 

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