HYDROXYLAMINE SULFATE PREPARATION PROCESS Russian patent published in 2005 - IPC

FIELD: industrial organic synthesis.

SUBSTANCE: invention relates to preparation of hydroxylamine sulfate used in caprolactam production. Process consists in catalytic steam-oxygen oxidation of ammonia and synthesis of hydroxylamine sulfate both carried out under elevated pressure (above 0.25 MPa), pressure in the steam-oxygen oxidation stage being higher than then in hydroxylamine sulfate synthesis stage by a value equal to aerodynamic resistance of equipment and pipelines installed between the two stages. Nitrose gas obtained after steam-oxygen oxidation stage is concentrated by condensing water vapors and freed of nitrogen dioxide, after which mixed with hydrogen for synthesis of hydroxylamine sulfate in dilute sulfuric acid solution. Nitric acid concentrate with 7-8.5% nitric acid releasing during concentration of nitrose gas is subjected to liquid-phase hydrogenation on platinum catalyst. Thus obtained pure nitrogen dioxide in mixture with hydrogen is sent to hydroxylamine sulfate synthesis stage and hydrogenation product containing up to 0.45% nitric acid is used to dilute concentrated sulfuric acid thereby providing wasteless technology.

EFFECT: simplified process flowsheet and automated process control, and reduced investment expenses of ammonia oxidation stage (by 65-70%).

3 cl, 2 dwg, 1 tbl