Patent ID: 7005547

Claim:
Process for the production of cyclohexanone oxime in which a phosphate-containing aqueous reaction medium is cycled from a hydroxylammonium synthesis zone (A) to a cyclohexanone oxime synthesis zone and back to the hydroxylammonium synthesis zone (A), in which hydroxylammonium synthesis zone hydroxylammonium is formed by catalytic reduction of nitrate with hydrogen, which cyclohexanone oxime synthesis zone comprises a reaction zone (B) and an extraction zone (C), said process comprising; (i) feeding the aqueous reaction medium to reaction zone (B), and from reaction zone (B) to extraction zone (C); (ii) feeding cyclohexanone and an organic solvent into the cyclohexanone oxime synthesis zone, cyclohexanone being fed to the cyclohexanone oxime synthesis zone between the reaction zone (B) and the extraction zone (C); (iii) in said reaction zone (B), reacting hydroxylammonium with cyclohexanone to form cyclohexanone oxime by contacting the aqueous reaction medium with a stream containing the cyclohexanone and the organic solvent; (iv) in said extraction zone (C), contacting the aqueous reaction medium and the organic solvent; (v) withdrawing an organic medium comprising the organic solvent and cyclohexanone oxime from the cycrohexanone oxime synthesis zone; and wherein the ratio f h /f c <1.00, wherein f h represents the molar quantity of hydroxylammonium fed to the cyclohexanone oxime synthesis zone per unit of time (in mol/s), and f c represents the molar quantity of cyclohexanone fed to the cyclohexanone oxime synthesis zone per unit of time (in mol/s).