Calcium ammonia from

The reaction may, therefore, be regarded as a synthesis of ammonia from its elements iu the presence of magnesium or calcium. 

Its principal use is in steelmaking, but it also goes into the manufacture of chemicals, water treatment, and pollution control. In the Solvay process, calcium carbonate and sodium chloride are used to produce calcium chloride and sodium carbonate with ammonia (which is recycled) as a medium for dissolving and carbonating the sodium chloride and calcium hydroxide for precipitating calcium chloride from the solution. 

Dimethylaniline has been prepared by reduction of the corresponding nitro compound, either chemically or catalyti-cally. It has been prepared from 3,4-dimethylphenol by heating with ammonia, ammonium bromide, and zinc bromide from w-toluidine hydrochloride by alkylation with methanol at high temperatures from anhydro-4-amino-2-methylbenzyl alcohol by dry distillation from calcium hydroxide from 2-methyl-S-aminobenzyl alcohol by reduction with sodium from 2-methyl-5-nitrobenzyl chloride and 2-methyl-S-nitrobenzyl acetate by catalytic reduction from o-xylene by direct amination with hy-droxylamine hydrochloride in the presence of aluminum chloride and from 3,4-dimethylacetophenone by the Beckmann rearrangement of the oxime.i" The present method has been published. ... 

Separation (partial) of the calcium nitrate from the digestion mixture by crystallizing out at low temperatures as its tetrahydrate. The calcium nitrate separated can be converted with ammonia/carbon dioxide to a mixture of calcium carbonate and ammonium nitrate (lime ammonium nitrate) (Odda process)... 

The Nitrates Products Co. Ltd. have secured the world s rights of this process outside Westphalia and Rhineland. They intend to produce their ammonia from the action of steam on nitrolime (calcium cyanamide). 

Ammonia from Cyanamide.—Cyanamide is made by causing atmospheric nitrogen to directly unite with calcium carbide, as described in Martin s Industrial Chemistry, Vol. II. Ammonia is next made from the cyanamide by passing superheated steam over it, when the following change takes place... 

In 1898 Frank and Caro in Germany developed the cyanamide route, in which very high temperatures were used to fix elemental nitrogen to obtain calcium cyanamide from calcium carbide (Eq. 11.4). Hydrolysis of calcium cyanamide then produced ammonia and calcium carbonate (Eq. 11.5). For many years the cyanamide produced predominantly went into ammonia synthesis. 

In the synthesis of the antidepressant (-)-Rolipram, Meyers et al. [26] tried to convert bicyclic lactam 39 to hydroxylactam 40 by use of dissolved metals. The increased yield of 40 on going from Li -> K -> Na parallels fhe reduction potential of the metals Li (3.0), K (2.9), and Na (2.7). The reduction potential of calcium is known to be even lower. When 39 is treated with calcium metal (10 equiv.) in liquid ammonia, fhe desired 40 is produced in 84% yield (Scheme 4.11). The same type of reduction is applicable to the conversion of 41 to 42 [27]. Furthermore, treatment of tricyclic lactam 43 wifh EtsSiH and I ifTi gives poor isolated yield (22%) of the polar diamino alcohol 44. In contrast, calcium-ammonia reduction of 43 produces N-unsubstituted hydroxylactam 45 in an excellent yield. 

Metallic bronze fh(N 11, ), can, furthermore, be prepared from calcium-ammonia solution by evaporation of the ammonia. A bronze sohd is obtained, which in TH F at -30 °C behaves as a sohd surface in its reaction with alkyl hahdes (Scheme 4.17) [39]. Its apphcation in the reduction of 61 b produces a mixture of cyclopropane derivative 62 (81%) and straight-chain diphenylbutane 64 (8%). The process involves the formation of a tight anion radical-cation radical as an intermediate. Carbon-halogen bond cleavage occurs on the surface of the metalhc cluster. 

Biofiltration can be used to remove volatile organic compounds, including odors, from waste air.295 Pseudomonas spp. can remove toluene, and Bacillus spp., ethanol. The process is suitable for use on food-processing plants, public treatment works, and others, to control odors. The cost can be quite a bit lower than that of incineration or adsorption on carbon. A biofilter with Nitrosomonas eu ropaea immobilized in calcium alginate removed 97.5% of ammonia from air.296... 

We should remember that urban air in Asian cities like Bangkok, Beijing or Seoul contains basic compounds, such as ammonia from automobile emissions or calcium oxide from cement kiln and dust. In these conditions, sulfuric acid will react to form salts... 

Discussion The preparation of ammonia from ammonium chloride and calcium hydroxide resembles the preparation of carbon dioxide from an acid and a carbonate in that a double decomposition is immediately followed by the spontaneous breaking up of one of the products into water and a gas. In both cases also the secondary reaction is reversible and with ammonia this reversal, together with the great solubility of ammonia gas itself, is so marked as to require the use of solid material instead of solutions, in order to reduce as much as possible the amount of water present. 

High-calcium limestone is not widely used in fertiliser formulations, as it can release ammonia from nitrogenous compounds. 

The structure of isoeremophilone 66 was established by correlation with the compound derived from calcium/ammonia reduction of the acetate of 1,11-diene (58). Alloeremophilone (67), also reported as a minor constituent of E. mitchelli, can be generated from the acetate of HDE (57) by pyrolysis, which also yields equivalent amounts of eremophilone (59). 

Granat s chemical relationship for European rainwater assumes the following sources and acidities/alkalinities sulfuric acid from air pollutants with two equivalents of acidity per mole, nitric acid from air pollutants with one equivalent of acidity per mole, ammonia from air pollutants with one equivalent of alkalinity per mole, sea salt with negligible alkalinity, calcium soil dust with two equivalents of alkalinity per mole, magnesium soil dust with two equivalents of alkalinity per mole, and potassium soil dust with one equivalent of alkalinity per mole(3). Cogbill and Likens added hydrochloric acid air pollutants with one equivalent of acidity per mole for the northeastern United States calculations(4). 

The sodium hydrogencarbonate is heated to give sodium carbonate and carbon dioxide. The ammonium chloride is heated with calcium oxide (from the first stage) to regenerate the ammonia. The process was patented in 1861 by the Belgian chemist Ernest Solvay (1838-1922). 

The other method was wet chemical . The finely powdered mineral was treated with nitric acid. It was attacked and some of it was dissolved. The solution contained calcium nitrate. The insoluble residue was partly not attacked tungsten mineral and partly a yellow precipitate, formed in the reaction. Scheele thought that this was the anhydride of the tungstic acid. The yellow precipitate could be dissolved in ammonia. From this solution tungstic acid was precipitated with diluted nitric acid... 

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