Nitric acid from nitrogen

Method 1. Place 20 g. of crude benzoin (preceding Section) and 100 ml. of concentrated nitric acid in a 250 ml. round-bottomed flask. Heat on a boiling water bath (in the fume cupboard) with occasional shaking until the evolution of oxides of nitrogen has ceased (about 1 -5 hours). Pour the reaction mixture into 300-400 ml. of cold water contained in a beaker, stir well until the oil crystallises completely as a yellow solid. Filter the crude benzil at the pump, and wash it thoroughly with water to remove the nitric acid. RecrystaUise from alcohol or methylated spirit (about 2-5 ml. per gram). The yield of pure benzil, m.p. 94-96°, is 19 g. 

Before 1900 the large-scale production of nitric acid was based entirely on the reaction of concentrated sulfuric acid with NaNOa and KNOj (p. 407). The first successful process for making nitric acid directly from Ni and O2 was devised in 1903 by E. Birkeland and S. Eyde in Norway and represented the first industrial fixation of nitrogen ... 

Investigation into the effect has been mainly devoted to reactions with red fuming nitric acid . It seems that in red fuming nitric acid a preliminary reaction results in the formation of a surface deposit of finely divided metallic titanium ignition or pyrophoricity can then be initiated by any slight impact or friction. The tendency to pyrophoricity increases as the nitrogen dioxide content of the nitric acid rises from zero to maximum solubility at about 20%, but decreases as the water content rises, the effect being nearly completely stifled at about 2% water. 

Atroschenko and Kargin (Ref 26, pp 223-268) describes several methods of prepn of coned nitric acid directly from oxides of nitrogen... 

It appears however that the reaction proceeds according to both equations simultaneously since ammonium nitrate and formaldehyde are formed according to equation (37) and C02, N2 and water according to equation (38). Some of the methylene groups and nitrogen atoms of hexamine are therefore not utilized for the production of cyclonite. The nitration of hexamine with nitric acid requires from four to eight times the theoretical amount of nitric acid. 

In making MA s from commercial oleums and anhyd nitric acids, nitrogen dioxide present in nitric acids, reacts with sulfuric acid forming nitrosylsulfuric acid... 

Cellulose nitrated by fixed quantities of N204 and CC14, whilst the quantity of nitric acid varied from 0 to 40 parts, after one hour yielded products differing in nitrogen content. The highest nitrogen content was reached by adding 8-20 parts of nitric acid (Fig. 129). 

In the event of a major plant accident, large quantities of nitrogen oxides could be released into the atmosphere and product nitric acid may well be released to the drains. There is little that can be done to provide for such a situation. The emphasis would be on dilution of any liquid wastes expelled. It would be left to the prevailing winds to disperse the nitrogen oxide cloud. Fortunately this gas cloud is not flammable, but it is highly toxic. Nitrogen oxide fumes either from nitric acid or from process gases may have a deceptive delayed action. The victim may feel no pain or discomfort at the time of the low-level inhalation, or for up to 48 hours thereafter, but then serious respiratory and cardiac problems can occur. 

The other source of nitrogen compounds in the chemical industry is nitric acid, obtained from the oxidation of ammonia... 

Vandoni [72] repeated the experiments of Sapozhnikov on the vapour pressure of HN03 over mixtures of HNO3-H2SO4-H2O using an improved technique. In the main, he confirmed the earlier results, but he introduced some corrections to the figures obtained by Sapozhnikov. Thus he used nitric acid free from nitrogen oxides which were present in the acid used by Sapozhnikov. Vandoni has shown... 

Derivation From dilute nitric acid, nitrogen dioxide, and oxygen. 

In a well-designed reprocessing plant, materials are recycled to the maximum extent practicable, to minimize the volume of effluents and reduce the cost of chemicals. Water and nitric acid evaporated from products and wastes are recycled. Nitrogen oxides are converted to nitric acid and reused. Solvent stripped of uranium and plutonium is cleaned of degradation products and contaminants in step 14 and reused. 

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