Hydrazine manufacture

This type of amination by an oxaziridine is assumed to be the key step of a novel process for hydrazine manufacture, in the course of which butanone in solution with ammonia is reacted with hydrogen peroxide and acetonitrile. The smooth formation of oxaziridines from Schiff bases and hydrogen peroxide-nitrile mixtures is as well known as NH transfer from an oxaziridine like (300), suggesting the intermediacy of (300) as the N—N forming agent (72TL633). 

Powell, R., Hydrazine Manufacturing Processes, Noyes Development Corp., Park Ridge, NJ, 1968. 

A relatively recent evaluation of the performance of nickel azide hydrazine manufactured by this procedure indicates it to be a safer, lead-free, primary explosive than lead styphanate or lead azide [12], For this reason it has also been explored as a charge for semiconductor-bridge initiators used for the initiation of high-explosive devices. Its best ignition performance parameters under optimal conditions have been evaluated by the same group [13]. 

Another type of polyol often used in the manufacture of flexible polyurethane foams contains a dispersed soHd phase of organic chemical particles (234—236). The continuous phase is one of the polyols described above for either slab or molded foam as required. The dispersed phase reacts in the polyol using an addition reaction with styrene and acrylonitrile monomers in one type or a coupling reaction with an amine such as hydrazine and isocyanate in another. The soHds content ranges from about 21% with either system to nearly 40% in the styrene—acrylonitrile system. The dispersed soHds confer increased load bearing and in the case of flexible molded foams also act as a ceU opener. 

Hydrazine [302-01-2] (diamide), N2H4, a colorless liquid having an ammoniacal odor, is the simplest diamine and unique in its class because of the N—N bond. It was first prepared in 1887 by Curtius as the sulfate salt from diazoacetic ester. Thiele (1893) suggested that the oxidation of ammonia (qv) with hypochlorite should yield hydrazine and in 1906 Raschig demonstrated this process, variations of which constitute the chief commercial methods of manufacture in the 1990s. 

Hydrazine forms a high (120.5°C) boiling azeotrope with water that has a composition of 58.5 mol % (71.48 wt %) N2H4 at 102.6 kPa (1.02 atm) pressure. This comphcates the separation of hydrazine from water in the manufacturing process because it necessitates the removal of a large amount of water in order to approach the azeotropic composition. 

MMHa.nd UDMH. MonomethyUiydrazine and yyz -dimethylhydrazine are manufactured by Olin Corp. using the same Raschig process and equipment employed for anhydrous hydrazine. Chloramine, prepared as described above, reacts with methylamine or dimethylamine instead of with... 

Chromium Removal System. Chlorate manufacturers must remove chromium from the chlorate solution as a result of environmental regulations. During crystallization of sodium chlorate, essentially all of the sodium dichromate is recycled back to the electrolyzer. Alternatively, hexavalent chromium, Cr, can be reduced and coprecipitated in an agitated reactor using a choice of reducing agents, eg, sodium sulfide, sulfite, thiosulfate, hydrosulfite, hydrazine, etc. The product is chromium(III) oxide [1333-82-0] (98—106). Ion exchange and solvent extraction techniques have also... 

Maleic hydrazide (149), produced on a large scale as a herbicide, can be obtained, according to a patent, from a simple diaziridine, which on an industrial scale could be less expensive than hydrazine hydrate. In the proposed manufacture of diamide (150) from a diaziridine and urea it must be taken into account that the reaction of urea is preceded by solvolytic hydrazine formation, which probably proceeds under the reported conditions (several hours, 70-80 °C, acidic media) (79AHC(24)63). 

World production capacity of hydrazine solutions in 1995 (expressed as N2H4) was about 40000 tonnes, predominantly in USA 165(X) t, Germany 6400 t, Japan 6600 t and France 6KX) t. In addition some 32(X) t of anhydrous N2H4 was manufactured in USA for rocket fuels. 

This is the basis of the iodofonn test for the CHiCO group. In addition to the.se reactions tliere is considerable industrial use for HOCl and hyfHxrhlorites in the manufacture of hydrazine (p. 427), chlorhydrins and or-glycols ... 

CAUTION NOTE Hydrazine is toxic, and suitable precautions for its handling should be observed. Its use is usually prohibited in hospitals, the food manufacturing industry, and where steam may come into contact with food or beverages. The use of sodium sulfite may also be unacceptable in some of these applications. The existence of any regulations governing the use of either should be ascertained and observed. 

In a factory manufacturing organo-iron and organo-manganese catalysts, use of cotton waste to mop up a spill of dilute hydrazine solution led to a spontaneous fire later. The fire was attributed to onset of rapid metal-catalysed decomposition of the hydrazine after sufficient water had evaporated from the waste, the traces of heavy metals originating from dust contamination, etc. 

Used in agriculture as a fertilizer and defoliant in the manufacture of nitric acid, hydrazine, hydrogen cyanide, urethanes, acrylonitrile, nitrocellulose, nitroparaffins, melamine, ethylene diamine, and sodium carbonate as an intermediate in producing explosives, synthetic fibers and dyes and used industrially as a refrigerant gas, neutralizing agent in the petroleum industry, latex preservative, and the production of fuel cells. 

Several amino compounds are being used extensively in industrial processes. Most of these compounds are manufactured, except hydrazine. Azo dyes are produced by diazotization of aromatic amines and currently there are at least 3000 azo dyes in use. These dyes are used widely in textiles, leather, printing, paper making, drug and food industries. In the past three decades many food, drug and cosmetic colours have been banned from commercial use as food colourants. This section gives a brief account of adverse affects caused by the use of various amino compounds. 

Uses Manufacture of acrylonitrile, hydrazine hydrate, hydrogen cyanide, nitric acid, sodium carbonate, urethane, explosives, synthetic fibers, fertilizers refrigerant condensation catalyst dyeing neutralizing agent synthetic fibers latex preservative fuel cells, rocket fuel nitrocellulose nitroparaffins ethylenediamine, melamine sulfite cooking liquors developing diazo films yeast nutrient. 

Rocket fuel factory and surroundings. Fine, et al (5) reported nitrosodimethylamine (NDMA) to be present as an air pollutant in Baltimore, Maryland. The prime source was subsequently found to be a chemical plant which was manufacturing the rocket fuel, unsymmetrical dimethyl hydrazine (UDMH), for which NDMA was used as a precursor. Typical NDMA levels were between 6000 and 36,000 ng/m3 on the site of the factory, about 1000 ng/m3 in the residential neighborhood adjacent to the factory and about 100 ng/m3 two miles away in downtown Baltimore. Typical daily human exposures to NDMA were calculated to be 39 Mg at the factory site, 10 Mg in the adjacent residential neighborhood and 1.0 Mg in downtown Baltimore. It is of interest to note that a leak of just 130 g. (4.7 ounces) NDMA per hour could have explained all the airborne NDMA emissions in Baltimore. 

The converse of this type of reaction has been used to determine hydrazine as a manufacturing impurity in the drug hydralazine by reaction of the hydrazine residue with benzaldehyde to form a volatile derivative for GC analysis. ... 

There are two methods for the manufacture of hydrazoic acid or its salts. One is derived from a number of investigations by Curtius [1] and is based on the action of nitrous acid on hydrazine ... 

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