苯甲腈选择性加氢制备苯甲胺的催化剂研究

发布时间：2018-02-24 23:06

  本文关键词： 苯甲腈 苯甲胺 催化加氢 固定床 稳定性　出处：《上海师范大学》2016年硕士论文　论文类型：学位论文

【摘要】：苯甲胺又称为苄胺,是一种重要的精细化工中间体和有机化工原料。随着我国化工产业的不断发展,苯甲胺的需求量也不断增加。目前,国内生产的苯甲胺年产量低,主要依靠进口,苯甲胺的生产主要集中在德国、美国、日本等国家。国内的苯甲胺生产工艺落后,因此,开发高效的苯甲胺生产工艺将具有较好的市场前景。本论文在固定床反应条件下,研究了苯甲腈加氢制备苯甲胺的催化剂与反应工艺条件,开发了性能优异的贵金属催化剂,贵金属含量相比于文献大大降低,反应条件温和,为苯甲睛加氢制备苯甲胺实现连续化工业生产提供了有益的理论基础。本论文的主要研究内容与结果如下：1.筛选不同的催化剂配方,确定了由浸渍法制备的负载型Pd/γ-Al2O3催化剂是苯甲腈加氢制备苯甲胺反应的最优催化剂。比较了活性金属不同负载含量对反应性能的影响,优化后活性金属负载量为0.5 wt%,优化了浸渍法的制备工艺条件。2.考察反应工艺条件对催化剂性能的影响,并对反应工艺条件进行了优化,合适的反应工艺条件为：反应温度70-90℃,反应压1.5 MPa,氢腈比10-40,质量空速≤0.5 h-1。在该条件下,苯甲胺的收率最高可以达到88.8%。3.考察催化剂稳定性,在优化的反应工艺条件下,催化剂稳定运行209 h。之后苯甲腈的转化率降至97%以下,对失活催化剂进行了表征分析,失活催化剂不存在明显的活性金属组分流失,金属Pd并未发生大量团聚。催化剂表面覆盖了一些吸附物质,导致催化剂比表面积、孔容和孔径均有所下降。覆盖物是导致催化剂失活的主要原因。
[Abstract]:Benzylamine, also known as benzylamine, is an important fine chemical intermediate and organic chemical raw material. With the continuous development of chemical industry in China, the demand for benzylamine is also increasing. At present, the domestic production of benzyl amine is low. Mainly relying on imports, the production of benzomethylamine is mainly concentrated in Germany, the United States, Japan and other countries. In this paper, the catalyst and reaction conditions for the hydrogenation of benzonitrile to benzyl methylamine were studied, and the noble metal catalyst with excellent performance was developed. Compared with the literature, the content of precious metals is much lower, and the reaction conditions are mild. The main contents and results of this thesis are as follows: 1. Screening different catalyst formulations. The supported PD / 纬 -Al _ 2O _ 3 catalyst prepared by impregnation method was determined to be the best catalyst for the hydrogenation of benzonitrile to benzamide. The preparation conditions of the impregnation method were optimized. 2. The effect of reaction conditions on the performance of the catalyst was investigated, and the reaction conditions were optimized. The suitable reaction conditions were as follows: reaction temperature 70-90 鈩，

本文编号：1532061