Hydroxylamines phosphate

An additional mole of ammonium sulfate per mole of final lactam is generated duting the manufacture of hydroxylamine sulfate [10039-54-0] via the Raschig process, which converts ammonia, air, water, carbon dioxide, and sulfur dioxide to the hydroxylamine salt. Thus, a minimum of two moles of ammonium sulfate is produced per mole of lactam, but commercial processes can approach twice that amount. The DSM/Stamicarbon HPO process, which uses hydroxylamine phosphate [19098-16-9] ia a recycled phosphate buffer, can reduce the amount to less than two moles per mole of lactam. Ammonium sulfate is sold as a fertilizer. However, because H2SO4 is released and acidifies the soil as the salt decomposes, it is alow grade fertilizer, and contributes only marginally to the economics of the process (145,146) (see Caprolactam). 

Dutch State Mines (Stamicarbon). Vapor-phase, catalytic hydrogenation of phenol to cyclohexanone over palladium on alumina, Hcensed by Stamicarbon, the engineering subsidiary of DSM, gives a 95% yield at high conversion plus an additional 3% by dehydrogenation of coproduct cyclohexanol over a copper catalyst. Cyclohexane oxidation, an alternative route to cyclohexanone, is used in the United States and in Asia by DSM. A cyclohexane vapor-cloud explosion occurred in 1975 at a co-owned DSM plant in Flixborough, UK (12) the plant was rebuilt but later closed. In addition to the conventional Raschig process for hydroxylamine, DSM has developed a hydroxylamine phosphate—oxime (HPO) process for cyclohexanone oxime no by-product ammonium sulfate is produced. Catalytic ammonia oxidation is followed by absorption of NO in a buffered aqueous phosphoric acid... 

Dente and Ranzi (in Albright et al., eds.. Pyrolysis Theory and Industrial Practice, Academic Press, 1983, pp. 133-175) Mathematical modehng of hydrocarbon pyrolysis reactions Shah and Sharma (in Carberry and Varma, eds.. Chemical Reaction and Reaction Engineering Handbook, Dekker, 1987, pp. 713-721) Hydroxylamine phosphate manufacture in a slurry reactor Some aspects of a kinetic model of methanol synthesis are described in the first example, which is followed by a second example that describes coping with the multiphcity of reactants and reactions of some petroleum conversion processes. Then two somewhat simph-fied industrial examples are worked out in detail mild thermal cracking and production of styrene. Even these calculations are impractical without a computer. The basic data and mathematics and some of the results are presented. 

These reactors for hquids and liquids plus gases employ small particles in the range of 0.05 to 1.0 mm (0.0020 to 0.039 in), the minimum size hmited by filterability. Small diameters are used to provide as large an interface as possible since the internal surface of porous pellets is poorly accessible to the hquid phase. Solids concentrations up to 10 percent by volume can be handled. In hydrogenation of oils with Ni catalyst, however, the sohds content is about 0.5 percent, and in the manufacture of hydroxylamine phosphate with Pd-C it is 0.05 percent. Fischer-Tropsch slurry reac tors have been tested with concentrations of 10 to 950 g catalyst/L (0.624 to 59.3 IbiTi/fF) (Satterfield and Huff, Chem. Eng. Sci., 35, 195 [1980]). 

Stoppage of natural gas-water streams due to the formation of gas hydrates is prevented by incorporation of a surface-active agent in such streams, e.g., a 15% aqueous solution of hydroxylamine phosphate, which inhibits the formation of gas hydrates and the agglomeration of hydrate crystallites into large crystalline masses [255],... 

HPO [Hydroxylamine phosphate oxime] A process for making caprolactam, an intermediate in the manufacture of polyamides. It differs from related processes, such as HSO, in producing less of the ammonium sulfate by-product. Developed by DSM Research, The Netherlands, operated by DSM Polymers and Hydrocarbons, and offered for license by Stamicarbon. 

Keywords hydroxylamine phosphate, acetone, large scale, exhaust gas purification, flow system, gas-solid reaction, acetone oxime... 

Other DCAs introduced in the 1960s included the phosphated hydroxy-amines (hydroxylamine phosphate esters), such as triethanolamine phosphate ester. These are efficient scale inhibitors and are still employed in formulations today, but, like P-PO4, they are also prone to reversion (hydrolysis) to orthophosphates. 

Two general methods may be employed in the preparation of hydroxylamine involving either the thermal dissociation of certain hydroxylamine compounds or the interaction of hydroxylamine hydrochloride suspended in an alcohol with the corresponding sodium alcoholate. The first of these methods was used both by Crismer,1 who distilled zinc chloride dihydroxylamate under reduced pressure and by Uhlenhut,2 who decomposed tertiary hydroxylamine phosphate. These procedures are extremely wasteful, owing to the instability of hydroxylamine at the temperatures required to bring about dissociation. Any hydroxylamine that is not isolated is totally lost. 

Of the processes based on modification of the conventional route, only Stamicarbon s hydroxylamine phosphate oxime (HPO) process completely avoid all production of ammonium sulfate before the Beckmann rearrangement. The steps in the HPO process are listed below and shown in Figure 21.146, 264 ... 

Figure 14. Enhancement of absorption of hydrogen into aqueous hydroxylamine phosphate solutions by catalyst loading of the bulk Tor a stirred-tank reactor. Drawn lines are model calculations with best-fit parameters (from Wimmers and Fortuin [122]).

Ammonium nitrate solution is reduced to hydroxylamine phosphate with hydrogen under pressure on a suspended precious metal catalyst (substrate activated charcoal) in the presence of phosphoric acid (HPO Hydroxylamine Phosphate Oxime) ... 

The HPO (hydroxylamine phosphate oxime) process, developed byDSMand licensed by Siamicarbon, totally eliminates the production of ammonium sulfate, both in the production of hydroxylamine itself and in die oxime production stage. It consists of the catalytic hydrogenation of the nitrate ions resulting from the oxidation of ammonia to hydroxylamine ions in a solution buffered by phosphates. The nitrate reduction reaction is as follows ... 

The Dutch State Mines process uses hydroxylamine phosphate oxime (HPO) to carry out the oximation of cyclohexanone. The process sequence is shown in Figure 14. In this process phosphoric acid/ammonium nitrate... 

Hydroxalamine disulfonic acid, 193 Hydroxylamine phosphate oxime (HPO), 219 Hydroxylamine sulfate, 192-194, 219 Hydroxylammonium phosphate, 219, 220 Hydroxylated polyesters, 160 Hypochlorus acid, 149... 

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