丙烷脱氢催化剂结焦性质表征与动力学研究

发布时间：2018-04-05 17:11

本文选题：丙烷脱氢　切入点：催化剂　出处：《华东理工大学》2017年硕士论文

【摘要】：丙烷脱氢是重要的丙烯生产工艺,Pt系催化剂在丙烷脱氢反应过程中具有较高的活性,但是催化剂在高温条件下容易因结焦而失活,对丙烷脱氢过程的经济性有重要影响。本文通过等量浸渍法分别制备了单Pt催化剂和PtSn催化剂,并与工业催化剂进行了比较。通过热重分析,拉曼光谱,热裂解气质联用等方法对结焦的催化剂进行了表征与分析。研究结果表明Pt系催化剂上的结焦可以分为芳香烃、脂肪烃和类石墨物质,脂肪烃的碳链长度在C8-C33之间连续分布。载体酸性的降低,提高了直链烷烃的比例。类石墨化的结焦具有二维片层结构。Sn和K等助剂的添加可以降低催化剂的结焦量,提高焦的石墨化程度。反应温度和丙烷分压的升高都会导致催化剂结焦量增加,焦的石墨化程度的升高;氢气分压的升高会导致催化剂结焦量的减少,焦的石墨化程度的降低。对工业催化剂结焦动力学的分析发现,结焦速率对丙烷分压的反应级数为0.9;对氢气分压的反应级数为-0.6;对丙烯分压的反应级数为0.6。研究结果对于丙烷脱氢催化剂的结焦抑制和新型催化剂设计开发具有一定的借鉴意义。
[Abstract]:Propane dehydrogenation is an important propene production process. Pt catalyst has high activity in propane dehydrogenation, but the catalyst is easily deactivated by coking at high temperature, which has an important effect on the economy of propane dehydrogenation.In this paper, single Pt catalyst and PtSn catalyst were prepared by the same amount of impregnation method, and compared with the commercial catalyst.The coking catalyst was characterized and analyzed by thermogravimetric analysis, Raman spectroscopy, pyrolysis and GC-MS.The results show that the coking on Pt catalyst can be divided into aromatic hydrocarbon, fatty hydrocarbon and graphite-like substance, and the length of carbon chain of fatty hydrocarbon is continuously distributed between C8-C33.With the decrease of carrier acidity, the ratio of straight chain alkanes is increased.The coke like graphitization can reduce the coking amount of the catalyst and increase the graphitization degree of coke by adding additives such as Sn and K with two-dimensional lamellar structure.The increase of reaction temperature and propane partial pressure will lead to the increase of catalyst coking amount and the graphitization degree of coke, and the increase of hydrogen partial pressure will lead to the decrease of catalyst coking amount and the decrease of coke graphitization degree.The reaction order of coking rate on partial pressure of propane is 0.9, that of hydrogen is -0.6, and that of propylene is 0.6.The results can be used for reference in the suppression of coking of propane dehydrogenation catalyst and the design and development of new catalyst.
【学位授予单位】：华东理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TQ221.212;O643.36

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