钛硅分子筛催化环己酮氨肟化反应过程--影响过氧化氢分解的因素分析

在实验室对钛硅分子筛催化环己酮氨肟化制备环己酮肟反应体系中引起H2O2分解的原因进行了考察。结果表明，最重要的因素是氨的过量所导致的碱性环境，维持反应体系低含量的氨和H2O2，有利于提高H2O2的有效利用率，反应温度的提高会造成H2O2的利用率略有下降，钛硅分子筛及加入的量对H2O2的分解几乎没有影响，但TiO2和硅胶的存在会对其分解有一些影响，反应器材质宜选不锈钢，使用前对其表面进行适当的酸、碱处理可消除其对H2O2分解的影响。这些结果可为H2O2进料方式的合理选择，反应器、分布器和混合器元件的优化设计提供依据。

AMMOXIMATION OF CYCLOHEXANONE TO CYCLOHEXANONE OXIME OVER HTS ZEOLITE--The effect Factors on Decomposition of Hydrogen Peroxide

The laboratory investigation result showed that the key effect factor on decomposition of hydrogen peroxide was the alkaline environment due to the presence of ammonia in the reaction system of ammoximation of cyclohexanone to cyclohexanone oxime over silicon-titanium zeolite (HTS). Maintaining proper ammonia concentration, hydrogen peroxide concentration and reaction temperature could improve the effective utilization rate of hydrogen peroxide. Raising temperature could drop the uti-lization rate of hydrogen peroxide; the HTS concentration had almost no effect on hydrogen peroxide decomposition; however; the presence of titanium dioxide and silica gel had some effect on the decomposition. Stainless steel was a suitable material for manufacturing the reactor. The effect of the material on hydrogen peroxide decomposition could be dispelled when its surface was treated with sodium hydroxide and nitric acid at a proper condition. The above results could provide the basis for reasonable selection of feeding way and optimizing the designs of reactor distributor and the elements of mixer.