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The Study On One-step Formation Of Cyclohexanone Oxime From Cyclohexane Ammoxidation

Posted on:2015-01-05Degree:MasterType:Thesis
Country:ChinaCandidate:S J WangFull Text:PDF
GTID:2251330428471973Subject:Organic Chemistry
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Cyclohexanone oxime is very importanrt chemical material, which is the precursor to engineering plastic and nylon6. Hydroxylamine method of cyclohexanone is generally used for the production of cyclohexanone oxime in traditional industries. This method not only requires multiple reaction steps, but also causes serious environmental pollution problems, because of the introduction of hydroxylamine and sulfuric acid. In the meantime, a large number of low value by-product ammonium sulfate, making the production efficiency affected. Therefore, people have been committed to the development of new synthetic routes. Then they have been completed by the multi-step liquid phase catalytic of cyclohexanone oxime etc. All these new methods require multistep reactions and cumbersome processes. The simplification of the production process route and reduction of environmental pollution have become the main research directions of cyclohexanone oxime production. From synthetic and industrial views, it is very meaningful to synthesize cyclohexanone oxime by a single ammoxidation with cyclohexane as raw material. In this thesis, the cyclohexanone oxime has been synthesized by the ammoxidation of cyclohexane, under the combined effect of hydrogen peroxide, ammonia and heterogeneous catalysts. The main research contents are as follows: (1) The one-step synthesis of cyclohexanone oxime by cyclohexane ammoxidation has been studied using TS-1in this project. Structure, synthesis, application of titanium silicon are summarized. The progress of cyclohexane catalyzed oxidation was reviewed, and the progress reaction and mechanism of cyclohexanone were summarized. On this basis, the route of one-step forming cyclohexanone oxime from cyclohexane ammoxidation was proposed.(2) A series of MxOy/TS-1catalysts were prepared for ammoxidation of cyclohexane with hydrogen peroxide. The catalysts were characterized by XRD and FT-IR. Effects of chromium source, Cr2O3loading amount and nitrogen source on the reaction were investigated. The best catalytic performances can be obtained when chromium nitrate was used as chromium source and ammonia as nitrogen source, Cr2O3loading amount was15%.(3) Above all,15%Cr2O3/TS-1catalysts were used for ammoxidation of cyclohexane. Following optimized reaction conditions are found through the experiment:cyclohexane1mL, catalyst0.1g, C6H12:H2O2:NH3·H2O=1:2.5:1(molar ratio), solvent8mL,70℃for6h, the conversion of cyclohexane reached8.6%and the selectivity for cyclohexanone oxime up to34.8%. Comparing the multi-step synthesis of cyclohexanone oxime, this process has the advantage of non-polluting. The method has the potential to simplify the process for preparing cyclohexanone oxime.(4) The selective oxidation reaction of cyclohexane to cyclohexanone with TS-1as catalyst has been devoted in this paper. The optimal experimental conditions are as follows:cyclohexane1mL, catalyst0.15g, solvent8mL, H2O2/cyclohexane=2.5(molar ratio),70℃for6h, and the conversion of cyclohexane can reach17.5%and the selectivity for cyclohexanone up to51.0%.
Keywords/Search Tags:cyclohexanone oxime, cyclohexane, titanium silicalite-1, ammoxidation, one-step
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