METHOD OF OBTAINING HYDROXYLAMINE SULPHATE Russian patent published in 2008 - IPC C01B21/14 

FIELD: chemistry.

SUBSTANCE: invention pertains to the method of producing hydroxylamine sulphate through a method of recovering nitrogen monoxide (NO) using hydrogen (H₂) on a catalyst in a sulphuric acid medium. In this method, hydroxylamine sulphate is synthesised through mixing concentrated nitrogen monoxide with pure hydrogen in a medium of 19% sulphuric acid on a suspended platinum catalyst. At the same time, secondary reactions take place, enriching the gas phase in the reactors, which can form an explosive mixture with hydrogen. For safety purposes, gases containing not more than 10.5÷11.5% volume of N₂O are released from the hydroxylamine sulphate synthesis reactors. These tail gases also contain 60÷70% hydrogen, 8÷14% volume of NO. For absorption of NO, it is recommended to use a 15÷26% solution of FeSO₄ with temperature during the absorption process of 10÷35°C and pressure of 0.1-0.4 MPa. After desorption, taking place at 85÷95°C and pressure of 0.105 MPa, concentrated NO is obtained (not lower than 94%), or NO containing gas during desorption, taking place at 30÷40°C through a current of hydrogen. To maintain concentration of nitrogen oxide outside the limits of explosiveness at the absorption stage, nitrogen is added, in quantity equal to that of the absorbed NO.

EFFECT: lower production costs; reduced pollution of the atmosphere with nitrogen oxides; increased production of caprolactam with minimal capital expenditure without increasing processing units for production of concentrated NO.

6 cl, 2 ex, 2 dwg