The Study On Liquid-phase Ammoxidation Of Cyclohexane Catalyzed By TS-1

Cyclohexanone oxime is very importanrt intermediates, which is the precursor to engineering plastic and nylon 6. With the development of the chemical fiber industry and the expansion of market demand, the production technology of cyclohexanone oxime has also been a rapid development. The reduction of nitrogen oxide, sulfuric acid and phosphoric acid hydroxylamine method of cyclohexanone are general used for the production of cyclohexanone oxime in traditional industries. These methods have been completed mainly through the method of preparation of hydroxylamine salt. Then they have been completed by the multi-step liquid phase catalytic of cyclohexanone oxime. These methods are general completed by multistep reaction and have many defects. The using of green technology, reduction of environmental pollution and simplification of the production process route have become the main research directions of the production of cyclohexanone oxime in the future. From the view of synthetic and industrial, it is very meaningful that the cyclohexanone oxime has been synthesized by one step reaction, using cyclohexane as raw material. In this paper, the cyclohexanone oxime has been synthesized by the liquid ammonia oxidation of cyclohexane. It is a new way to synthesize the cyclohexanone oxime. Main works of this research are listed as following:(1) The study on liquid-phase ammoxidation of cyclohexane catalyzed by TS-1was focused in this paper, and then structural features, synthesis, application of titanium silicon are summarized.The progress of cyclohexane catalyzed oxidation was reviewed, the gas phase oxidation and the liquid-phase oxidation catalytic systems were focucsed.And the progress reaction and mechanism of cyclohexanone were summarized.(2) The catalytic process of cyclohexane was studied on HTS-1 in hydrogen peroxide. The amount of catalyst, reaction temperature, reactant ratio, reaction time and catalyst reuse on HTS-1 were investigated. It was found that there is no pollution and simple process compared with multi-step synthesis, and the optimum conditions as follows:amount of HTS-1 was 0.2g, cyclohexane, hydrogen peroxide, ammonia ratio was 1.2:1:1 in 70℃for 8h, the conversion of cyclohexane can reach 16.7%, the cyclohexanone Oxime selectivity can reach 20.4%. This method is likely to more simpler.(3) It was found that high content of unknown product in synthesis of cyclohexanone oxime reaction by one-step with acetonitrile.The structure was obtained by silica gel column, IR, and NMR, the results show that the presence of HTS-1, ammonia and hydrogen were resulted in hydrolysis of acetonitrile and the hydrolysis product is acetamide. And cyclohexane oxidation with HTS-1 was investigated, the results showed that:0.3 gHTS-1,0.2 mol cyclohexane,0.2 mol H2O2 for 8 h in 70℃cyclohexane conversion can reach to 30.1%.(4) Based on the literature of cyclohexanone ammonia oxidation reaction on TS-1, the cyclohexanone peroxide as raw material, reaction temperature, catalyst amount, ratio of reactants, different solvents and different catalysts were investigated. Comparing the two different reactants in the reaction rate under the same conditions, the results show that the conversion of cyclohexanone peroxide was 18.2%, the selectivity was 58.5%, and conversion of cyclohexanone was 28.3%.It was proved that oxidation of cyclohexanone peroxide was slowly steps compared with ammonium oxidation of cyclohexanone. Therefore, cyclohexanone oxime could produce by imine mechanism or hydroxyl ammonia mechanism.