Ammonia/ammonium production

Manufacture. Historically, ammonium nitrate was manufactured by a double decomposition method using sodium nitrate and either ammonium sulfate or ammonium chloride. Modem commercial processes, however, rely almost exclusively on the neutralization of nitric acid (qv), produced from ammonia through catalyzed oxidation, with ammonia. Manufacturers commonly use onsite ammonia although some ammonium nitrate is made from purchased ammonia. SoHd product used as fertilizer has been the predominant form produced. However, sale of ammonium nitrate as a component in urea—ammonium nitrate Hquid fertilizer has grown to where about half the ammonium nitrate produced is actually marketed as a solution. 

For binder preparation, dilute hydrochloric or acetic acids are preferred, because these faciUtate formation of stable silanol condensation products. When more complete condensation or gelation is preferred, a wider range of catalysts, including moderately basic ones, is employed. These materials, which are often called hardeners or accelerators, include aqueous ammonia, ammonium carbonate, triethanolamine, calcium hydroxide, magnesium oxide, dicyclohexylamine, alcohoHc ammonium acetate, and tributyltin oxide (11,12). 

Reactions of ammonia and amines with carboxyUc acids result in the formation of a variety of products (47,48). Ammonium salts, RCOONH, are prepared with or without solvent, by reaction with anhydrous ammonia. Ammonium salts readily decompose to acid ammonium salts,... 

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... 

Antimony pentachloride also unites with ammonia. Two products are formed by passing ammonia gas into cold antimony pentachloride, namely, triammino-antimony pentachloride, [Sb(NH3)3]Cl3, and tetranunino-antimony pentachloride, [Sb(NH3)1]Cl5.1 Triammino-antimony pentachloride is a red substance which decomposes on heating, with formation of a sublimate of composition 3NH4Cl.SbCl5. Tetram-mino-antimony pentachloride is a white volatile substance which decomposes into antimony ammonium chloride. NH4Cl.SbCls, on treatment with hydrochloric acid. 

It should be noted that the method of Section A gives ammonia by-product which can be used to prepare more urea. However, Section B gives ammonium chloride, which requires costly conversion into free ammonia. 

Ammonium Azide Ammonates, Ammonium azide forms with ammonia addition products a)Monoammonate, NH4N3-NHa, its existence was established from a study of the system ammonium azide-ammonia (Refs 7 8) b) Diammonate, NH4Na 2NH3, clear, col elongated plates stable at -33°, but incapable of existence at 0° (Ref 7) c)Tetrammonate,... 

Ammino-orthoarsenates of composition Co3(As04)2(NH3).7H20, Co3(As04)2(NH3)2.6H20 and Co3(As04)2(NH3)3.5H20 have been obtained by the interaction in solution of a cobalt salt, arsenic acid or an arsenate and free ammonia, ammonium salts being present.7 The nature of the product depends on the amount of free ammonia present. 

When an aq. soln. of trimetaphosphimic acid, or of one of its salts, acidified with one of the stronger mineral acids, is heated or kept for a long time, decomposition occurs—slowly if cold, rapidly if heated. Orthophosphoric acid and ammonia (ammonium phosphate) are the ultimate products of the decomposition. Several intermediate products have been detected in addition to pyrophosphoric acid, what H. N. Stokes calls diimidotriphosphoric acid, and imidodiphosphoric acid have been found, and he represents the different stages of the decomposition ... 

Coke production was formerly the most important demonstrated technology associated with the direct production of chemicals from coal. Industrial chemicals currently obtained in significant amounts as coke byproducts include benzene, toluene, xylene, naphthalene, anthracene, phenanthrene, phenol, ammonia, ammonium sulfate, sulfitr, and carbon dioxide. The vast majority of aromatics production from coal occurs in Eastern Europe, India, and Japan.75... 

The high-volume use of these solutions is a result of their economy of production and the safety and convenience of their handling and application. The use of nonpressure equipment and surface application (in contrast to knifing) is normal. Nitrogen solutions of other compositions also are prepared commercially, but are used primarily as intermediates in the preparation of solid fertilizers. Such solutions usually consist of various combinations of water, ammonia, ammonium nitrate, and/or urea. Because of the content of free ammonia, most of these solutions require pressurized handling. 

Materials. Origin and characteristics of the cellulose samples used are listed in Table I. The low molecular weight cellulose sample A, was prepared from American Enka rayon by hydrolysis in 4 M HCl for 15 minutes and then washed with an eluotropic series of solvents. Sheets of samples C and D were shredded in a Wiley Mill (40 mesh) before use. Sample B, with degree of polymerization DP) of 210, was used in this study except where noted. Ammonium thiocyanate (Witco Chemical) was dissolved in condensed anhydrous ammonia (Air Products). Unless otherwise noted, all chemicals were ACS reagent grade. 

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