【作者】 欧阳南；

【导师】 陈丰秋；

【作者基本信息】 浙江大学 ， 化学工程， 2003， 硕士

【摘要】 吡啶类化合物有着十分广泛的用途，其来源主要有两种：一种是提炼法，另一种是化学合成法。自二十世纪50年代工业化以来，化学合成法已成为吡啶类化合物的主要生产方法。近年来我国化工行业以及饲料行业的迅速发展，国内对吡啶类化合物的需求量日益增长，但国内尚未有成熟的、有自主知识产权的合成技术及工业生产装置。因此，进行合成吡啶类化合物的国产化技术开发已十分必要和迫切。鉴于此，针对以甲醛、乙醛和氨气为原料合成吡啶类化合物的技术路线，本课题组于1999年开始开展催化剂及其工艺条件的实验研究，并取得了初步的研究成果。在此研究基础上，本文主要针对此类反应的催化剂容易失活，再生后催化剂又能重复使用的特点，着重考察了催化剂的失活和再生行为及其影响因素，为催化剂的进一步改进提供了技术依据。 由催化剂的失活实验研究中得出，原料气中氨气的比例越大，越有利于吡啶的生成，但不利于3-甲基吡啶的生成，同时催化剂也越容易失活；原料气中的水蒸气的存在使催化剂表面保持清洁，并能延缓催化剂的失活。实验还发现，催化剂失活的主要形式是催化剂表面的积炭，在本实验的操作条件下，催化剂上的积炭量Cc（g／g.cat）随反应时间t（hour）变化的关系式为： Cc=0.01684t^0.62644 通过催化剂再生的实验研究，发现此类失活催化剂的再生较佳温度在770K～800K之间。再生反应空速对催化剂再生有显著影响，并存在一最佳值，在本实验的操作条件下，再生的最佳空速为3000h^-1左右。研究结果还表明：再生除去了初始碳含量的99％以上，催化剂的活性能基本恢复，达到工业再生的要求。最后，还获得了此类失活催化剂在再生温度为725K～800K之间、再生反应空速为2500h^-1下的再生动力学方程为： 考虑到环保问题及反应过程的集成，再生过程中尽量多的生成CO，少生成CO₂。因此，我们采用了升高再生反应温度、降低再生反应空速的措施。 浙江大学硕士学位论文 在综合文献调研的基础上，本文另外还开展了催化剂改性的实验研究。用Z广和 Vy元素分别对ZSM6型催化剂进行改性后，毗院和 3．甲基0比陡的得率显著提高，其中V外元素改性的催化剂更有利于3．甲基毗陡的生成；用钻或钒金属离子对催化剂进行改性后，反应目的产物的总得率比催化剂改性前增长了15％～20％。研究结果还表明：钒型催化剂具有较高的活性，铅型催化剂则具有较好的稳定性。更多还原

【Abstract】 Pyridine bases are widely used in Chemical industry since the industrialization of their synthetic technology in the 1950’s. There are two main sources about pyridine bases: One is distilling from coal tar, the other is chemical synthesis. With the rapid development of chemical industry and feedstuff industry in our country, the demand of pyridine bases is expanded increasingly. As far as the independent property for synthetic technology and the manufacture equipment in our country are concerned, it’s a blank in this area. Then it is exigent and necessary to exploit our own technology to produce pyridine bases. Further research has been experimented on catalysts and the technical conditions of synthesis, which used formaldehyde . acetaldehyde and ammonia as raw material since 1999 to improve the activity of catalysts. Based on the easily deactivation and the rapidly regeneration of this kind of catalyst which can be used times, more attentions were paid on the factors in order to provide theoretical and practical guidance for catalysts’ further improvement.The experiments on catalyst’s deactivation showed that the more ratio of the ammonia in the gas of raw material, the more yield of pyridine and the less that of 3-picoline. The catalyst was prone to deactivation when the proportion of ammonia in the raw materials was large. The content of water in the raw materials can restrains the catalyst’s deactivation because of keeping the catalyst cleanly. At the same time, the results of experiments indicated that the catalyst’s deactivation was made up of two parts: one was caused by ammonia called poisoning-deactivation, the other was caused by formaldehyde . acetaldehyde ,called coking. But the latter was the main reason for catalyst’s deactivation. The connected equation of accumulated carbon with the deactivated time was: Cc=0.01684 t062644.After a series of experiments on the behavior of catalyst’s regeneration, the optimum conditions were obtained: the optimum temperature of regeneration was between 770 K and 800 K; the optimized space-velocity of regeneration was about 3000 h-1, and the influence of the regeneration space-velocity was significant. On these conditions, more than 99 percent of the original accumulated carbon could be burnt out, the activity of catalyst could be restored mostly, and it could be satisfied to the need of industry. Finally, when the temperature of regeneration was between 725K and 800K, the regeneration equation for this deactivated catalyst was shown as following:On considering the environment and the integration of process, more carbon monoxide is expected in the waste gas during catalyst’s regeneration, but carbon dioxide is on the contrary. For this destination, elevating the reaction temperature and reducing the space-velocity were adopted.inBased on summarizing the literature, this thesis has researched the alteration of catalyst also. The results showed that catalyst dipped with vanadium or zirconium could improve the total yields of pyridine bases remarkably. At the same time, the catalyst dipped with vanadium element was more propitious to the manufacture of 3-picoline. The total yields of pyridine and 3-picoline was improved by from 15 percent to 20 percent through the alteration of catalysts with zirconium or vanadium element. Moreover, the results of experiments exhibited that the catalyst dipped with vanadium has much higher activity, while the catalyst mended with zirconium exhibited long-term stabilities.更多还原