Studies Of Catalytic Oxidation Of Cyclohexane To KA Oil By Hemin And Its Derivatives

KA oil(cyclohexanone and cyclohexanol)is an important organic chemical product,can be used as an excellent solvent,is an important intermediate for synthesis of caprolactam,adipic acid and other chemicals.Due to the complexity of cyclohexane oxidation reaction,we should controle the conversion rate of cyclohexane to obtain the high selectivity of KA oil.Therefore,this reaction has the disadvantages of high energy consumption and low raw material utilization.Therefore,it is of great scientific significance and application prospect to study the technical method for further improving the reaction conversion and selectivity of KA oil prepared by air oxidized cyclohexane.In this paper,we studied metal porphyrins catalysts modified by hemin on the preparation of KA oil by air oxidation of cyclohexane.Combined with the existing equipment of KA oil production in Juhua polyamide company,the idesa of industrial application were put forward.1.Through modification of heme chloride,four commonly used metalloporphyrin compounds with stable structure and multiple activities were prepared and the key structures of some products were characterized by liquid chromatography and NMR.2.We tested catalytic properties of three kinds of hemin,two kinds of tetraphenyl porphyrins and four kinds of metal porphyrins modified by hemin and found that the catalyst could shorten the induction time of the reaction,and the induction time of tetraphenyl porphyrin was the shortest.Among the four kinds of modified porphyrins,mesopoporphyrin cobalt dimethyl ester has the best catalytic activity.Under the same reaction conditions,when the reaction time is 3.0 h,the highest conversion rate of cyclohexane can reach 11.4%,and the selectivity of the target product is 87.3%.Deuteroporphyrin cobalt dimethyl ester in the target product selectivity control is better.3.In batch kettle reaction,we used mesopoporphyrin cobalt dimethyl ester as catalyst to investigate the influence of reaction temperature,reaction pressure,amount of catalyst,air volume,HEDP ester and other factors on cyclohexane oxidation reaction.The most suitable reaction conditions were: reaction temperature of 150 ℃,reaction pressure of 0.80 MPa,catalyst concentration of 0.8 mg/L,air flow rate of400 m L/min.Under the reaction conditions of 3.0 h,the conversion rate of cyclohexane could reach 11.4% and the selectivity of the target product was 87.3%.4.In order to make the experimental conditions closer to the actual production device,we set up a continuous experimental device.Due to the poor mass and heat transfer in the bubbule-tube reactor,the reaction conversion rate and selectivity are lower than that in the batch reactor under the same experimental conditions,which is the same as that in the actual production unit.Finally,we put forward some suggestions and ideas for the industrial application of the catalytic technology of metalloporphyrin in the preparation of KA oil by air oxidation of cyclohexane.