An Integrated Process of H₂O₂ Production through Isopropanol Oxidation and Cyclohexanone Ammoximation

Abstract

The possibility of the integration of the processes of H 2 O 2 production through isopropanol partial oxidation and the direct ammoximation of cyclohexanone with H 2 O 2 and NH 3 catalyzed by TS-1 was investigated. The results of isopropanol partial oxidation showed that around 7.5 % yield of H 2 O 2 was obtained at 110 C, 10 atm, 2 h, and after fractionation, a H 2 O 2 solution with the typical composition 25.2 wt.-% H 2 O 2 , 10.3 wt.-% isopropanol, 0.29 wt.-% acetone, 0.45 wt.-% phosphoric acid and 0.43 wt.-% acetic acid was obtained. The presence of these impurities up to the above levels did not appreciably influence the ammoximation of cyclohexanone in terms of the conversion of cyclohexanone and the selectivity to cyclohexanone oxime. The results indicate that the processes of H 2 O 2 production through isopropanol partial oxidation and the ammoximation of cyclohexanone can be integrated.

Reaction mechanism of the ammoximation of ketones catalyzed by TS-1

“…The procedure for the ammoximation reactions of ketones was described before [12][13][14]. The reaction conditions were those optimized with cyclohexanone as the substrate [12][13][14].…”

“…The reaction conditions were those optimized with cyclohexanone as the substrate [12][13][14]. Qualitative and quantitative analysis of the products were performed by a HP-5890 gas chromatography using an OV-17 column and a FID detector.…”

“…Since the discovery of this _________________________ * Corresponding author. Phone/Fax: +86-22-27406335; E-mail: yqwang@tju.edu.cn catalytic process, it has been intensively studied [1][2][3][4][5][6][7][8][9][10][11][12][13][14]. Two reaction mechanisms have been proposed: in the first, a ketone reacts with ammonia, forming an imine, which is then oxidized to oxime by hydrogen peroxide [2][3][4][5].…”

Process integration of H2O2 generation and the ammoximation of cyclohexanone

“…We have studied an integrated process for cyclohexanone oxime production, in which isopropanol is first oxidized to generate H 2 O 2 , then acetone and unreacted isopropanol are distilled out from the oxidation mixture and recycled, and the H 2 O 2 solution is used in the ammoximation of cyclohexanone with t-butyl alcohol as solvent. 11 If cyclohexanone oxime can be produced with high yield in an isopropanol-based solvent, only acetone, rather than acetone and isopropanol, needs to be separated after the partial oxidation of isopropanol and the H 2 O 2 solution with unreacted isopropanol can be directly used in the ammoximation reaction (see Fig 1).…”

Catalytic mechanism and reaction pathway of acetone ammoximation to acetone oxime over TS-1

“…The conventional route involves multiple reaction steps, hazardous chemicals like oleum, halides or oxides of nitrogen and, more seriously, a large amount of low-value by-products like ammonium sulfate are produced. In recent years, a new catalytic process for the manufacture of oximes has been developed in liquid phase over titanium silicate, especially TS-1, employing NH 3 and H 2 O 2 as the ammoximation agents [2,3], which becomes increasingly important because it is an efficient and environmental friendly route. Liang et al [1] studied the effects of reaction conditions (solvents, reaction temperature, catalyst amount, the molar ratio of NH 3 /acetone) on the conversion and selectivity of the reaction.…”