Effect of Oxygen on Cyclohexane Oxidation: A Stirred Tank Study

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• 作者：Radmila Jevtic ; P. A. Ramachandran ; Milorad P. Dudukovic
• 刊名：Industrial & Engineering Chemistry Research
• 出版年：2009
• 出版时间：September 2, 2009
• 年：2009
• 卷：48
• 期：17
• 页码：7986-7993
• 全文大小：281K
• 年卷期：v.48,no.17(September 2, 2009)
• ISSN：1520-5045

文摘

Cyclohexane oxidation is the first step in the currently used technology for production of Nylon-6 and Nylon-6,6 which employs a two-stage process. In the first stage, cyclohexane is oxidized with air to 4−8% conversion at about 80% selectivity to cyclohexanol and cyclohexanone as desired products. In this study, we examined the effect of oxygen availability on the volumetric productivity, yield, and selectivity of this reaction by using a stirred autoclave operated free from mass transfer effects in a batch and “dead-end” semibatch mode. Both uncatalyzed and catalyzed systems were used. The experimental and the modeling results lead to the conclusion that increased oxygen availability improves the productivity and selectivity at the fixed cyclohexane conversion (4%) as the residence time required declines with the increase in oxygen concentration. The positive effect on the reaction rate of increased oxygen concentration is the same when such an increase is achieved at constant pressure by raising the mole fraction of oxygen in the feed or by raising the total pressure in the system at fixed oxygen mole fraction.