Patent ID: 7785549
Filing Date: 2010-08-31
Classification: C01B,C07C

Abstract:
1. A recycling system for hydroxylamine formation and oximation, comprising: (a) a hydroxylamine formation zone in which nitrate is reduced to hydroxylamine with a hydrogen gas in the presence of a catalyst in an inorganic process solution containing an acidic buffering agent; (b) an oximation zone in which hydroxylamine formed in the hydroxylamine formation zone and cyclohexanone are subjected to an oximation reaction to form cyclohexanone oxime; (c) a pre-mixing tank connecting the hydroxylamine formation zone and the oximation zone; (d) a purification zone in which organic impurities in the inorganic process solution are removed; and (e) an adjusting zone having a nitric acid absorption tower for supplementing nitrate ions to the inorganic process, wherein the inorganic process solution fed into the adjusting zone comprises a first portion that is fed to the nitric acid absorption tower, and a second portion that is not fed to the nitric acid absorption tower, such that the volume of the first portion of the inorganic process solution does not exceed 20% (by volume) of the total volume of the inorganic process solution, and in which the first portion of the inorganic process solution, after being supplemented with nitrate ions in the nitric acid absorption tower, is mixed with the second portion of the inorganic process solution.