Abstract: The invention relates to a process for treating an aqueous medium containing cyclohexanone oxime and cyclohexanone, said process comprising stripping the aqueous medium with steam, wherein said stripping is carried out at a pressure higher than 0.11 MPa. The invention also relates to a process for the preparation of cyclohexanone oxime, which involves stripping at a pressure higher than 0.11 MPa.

Abstract: The invention relates to a process for treating an aqueous medium containing (i) phosphate and (ii) cyclohexanone and/or cyclohexanone oxime, said process comprising: feeding the aqueous medium to a stripping zone; passing steam through the aqueous medium in the stripping zone; and discharging a vapor stream from said stripping zone; wherein the joint content cyclohexanone and cyclohexanone oxime in the aqueous medium entering the stripping zone is less than 0.08 wt. %.

Abstract: The invention relates to a process for reducing the aldehyde concentration in a mixture comprising cyclohexanone and one or more aldehydes, said process comprising distilling said mixture in a distillation column in the presence of an alkaline compound, wherein in the bottom of the distillation column substantially no water is present.

Abstract: The invention relates to a process for mixing a first acidic aqueous solution comprising hydroxylammonium and phosphate with a second acidic aqueous solution comprising nitric acid at a temperature between 20 and 80° C. resulting in a third acidic aqueous solution comprising hydroxylammonium, phosphate and nitric acid, wherein in the third acidic aqueous solution the total acid concentration minus the phosphate concentration is lower than 0.523*ln([hydroxylammonium]/1.25)+422/(T+81) whereby [hydroxylammonium] is the concentration of hydroxylammonium in the third acidic aqueous solution, T is the temperature of the third acidic aqueous solution expressed in ° C. and all concentrations are expressed in mol/l.

Abstract: The invention relates to a process for treating an organic solution comprising cyclohexanone oxime, cyclohexanone and an organic solvent, said process comprising distilling the organic solution such as to obtain (i) a first product comprising organic solvent, (ii) a second product comprising cyclohexanone and (iii) a third product comprising cyclohexanone oxime; and feeding the second product to a cyclohexanone oxime synthesis zone in which hydroxylammonium is reacted with cyclohexanone to form cyclohexanone oxime.

Abstract: The invention relates to a process for preparing nitric acid by treating an aqueous medium containing organic compounds and phosphate, said process comprising: feeding the aqueous medium to a nitric acid synthesis zone; forming nitric acid by contacting the aqueous medium with a gaseous medium in said nitric acid synthesis zone, said gaseous medium containing NO2?; discharging an off-gas from said nitric acid synthesis zone; wherein the total organic carbon concentration in the aqueous medium entering the nitric acid synthesis zone is less than 0.03 wt. %.

Abstract: The invention relates to a process for treating an aqueous medium containing cyclohexanone oxime and cyclohexanone, said process comprising stripping the aqueous medium with steam, wherein said stripping is carried out at a pressure higher than 0.11 MPa. The invention also relates to a process for the preparation of cyclohexanone oxime, which involves stripping at a pressure higher than 0.11 MPa.

Abstract: The invention relates to a process for the preparation of hydroxylammonium, said process comprising the steps of: a) feeding gaseous hydrogen to a reaction mixture, said reaction mixture comprising an aqueous reaction medium and a gaseous phase; b) catalytically reducing, in said reaction mixture, nitrate or nitrogen oxide with hydrogen to form the hydroxylammonium; c) withdrawing a gas mixture from the reaction mixture, said gas mixture comprising gaseous hydrogen and gaseous non-hydrogen compounds; d) separating at least part of the gaseous non-hydrogen compounds from the gas mixture to obtain a hydrogen-enriched gas; and e) passing the hydrogen-enriched gas to a hydrogenation zone.

Abstract: The invention relates to a process for treating an aqueous medium containing (i) phosphate and (ii) cyclohexanone and/or cyclohexanone oxime, said process comprising: feeding the aqueous medium to a stripping zone; passing steam through the aqueous medium in the stripping zone; and discharging a vapor stream from said stripping zone; wherein the joint content cyclohexanone and cyclohexanone oxime in the aqueous medium entering the stripping zone is less than 0.08 wt. %.

Abstract: The invention relates to a process for the production of cyclohexanone oxime in which a phosphate-containing aqueous reaction medium is cycled from a hydroxylammonium synthesis zone to a cyclohexanone oxime synthesis zone and back to the hydroxylammonium synthesis zone, in which hydroxylammonium synthesis zone hydroxylammonium is formed by catalytic reduction of nitrate with hydrogen, and in which cyclohexanone oxime synthesis zone hydroxylammonium is reacted with cyclohexanone to form cyclohexanone oxime, where the concentration hydroxylammonium in the aqueous reaction medium entering the cyclohexanone oxime synthesis zone is higher than 1.0 mol/l.

Abstract: The invention relates to a process for the production of cyclohexanone oxime in which a phosphate-containing aqueous reaction medium is cycled from a hydroxylammonium synthesis zone to a cyclohexanone oxime synthesis zone and back to the hydroxylammonium synthesis zone, in which hydroxylammonium synthesis zone hydroxylammonium is formed by catalytic reduction of nitrate with hydrogen, and in which cyclohexanone oxime synthesis zone hydroxylammonium is reacted with cyclohexanone to form cyclohexanone oxime, where the concentration hydroxylammonium in the aqueous reaction medium entering the cyclohexanone oxime synthesis zone is higher than 1.0 mol/l.