Study On Industrial Technology Of Biomimetic Catalytic Oxidation Of Cyclohexane

Cyclohexane oxidation is the main method to prepare cyclohexone in industry Considerable research effort has been spent on how to realize the cyclohexane oxidation under the milder conditions. Mimicry for biological oxygenation catalyzed by metalloporphyrin made an inspirational results for selective oxidation of cyclohexane with molecule oxygen. Developing the industry technology of mimicry for biological oxygenation of cyclohexane, realizing the industry process of oxidation of inert C-H bond under the mild condition by the mimic-biological catalysis oxidation will open the new complexion for selectivity oxidation of hydrocarbon, provide the important guidance and referrence for the related key industry process. The industrial process of cyclohexane oxidation with air in the presence of metalloporphyrin catalyst to produce cyclohexanone has been studied in this paper. On the basis of the experimental research, the dynamics rules of batch and continuous reaction system had been studied, the dynimic model of the cyclohexane oxidation was developed, which was corrected by the experimental results of the medium-sized equipment of three stirred-reactors in series. The simulation calculation of the reaction process was also proceeded. According to the research above, the design of the plant with the extended capacity of 12.4kt/a from 7kt/a have been completed. The oxidation reactor's reconstructed effect was optimized by the CFD technology.The main research works and results are as follows:(1) The initial temperature of cyclohexane oxidation to cyclohexaone was 142℃and the oxidation reaction initial time can be shortened over the temperature 148℃. Cyclohexane oxidation reaction was a complicated consecutive process; the reaction selectivity was decreased with the increasing of the residence time and the conversion of cyclohexane. The backmixing of materials was also a reason resulted in the decrease of selectivity of reaction. When the tail oxygen concentration was up to 7%, the speed of mass transfer of oxygen had no effect on the reaction; the varieties oxygen concentration was zero series to the oxidation speed. Under the same conversion, the selectivity of reaction was higher under the low temperature for a long time than the conditions under the high temperature for a short time.(2) The dynamic model of the biomimetic catalytic oxidation reaction of cyclohexane was established, which can reflect the dynamic rules of the oxidation of cyclohexane properly. The simulation results of the oxidation process using the dynamic model corrected were showed that under the same conversion, the selectivity of the reaction was increased with the increasing of the number of stirred tank in series, what's more, the selectivity was increased evidently under the related lower temperature. (3) The flow routes, distribution of gas holdup, distribution of turbulent Kinetic Energy and shear StrainRate in reactor and the change trend with the radial position under different industrial cases were simulated and contrasted by the CFD technology, the stirrer's operation area coverage, condition of carrier point and flooding point were analysed as well. The reason affected the reactor efficiency was found and advises on realizing the uniform distribution of the concentration and temperature, gas and liquid disperse were provided.