丙炔对Pt系催化剂上对丙烷脱氢反应的影响

发布时间：2018-06-25 13:30

本文选题：丙烷脱氢 + 丙炔　；参考：《华东理工大学》2017年硕士论文

【摘要】：丙烷脱氢正日益成为丙烯生产的重要工艺,但现有工艺仍存在催化剂结焦失活等问题。结焦组成和机理研究将为这一问题的解决提供重要支持。丙炔是丙烷脱氢反应中的重要中间物种,是裂解副反应的起始物质,对结焦反应可能也有重要影响。本研究通过将丙炔引入丙烷脱氢体系,提高脱氢过程的副反应程度,结合热解气质联用、拉曼、红外、元素分析、热重分析表征结焦的性质,探索丙烷脱氢过程结焦反应路径。研究结果表明Pt系催化剂上丙烷脱氢反应的结焦可分为三类:类石墨物质,多环芳烃和碳原子数连续分布的长直链烷烃;推出了较为完整的丙烷脱氢反应结焦路径,发现丙炔对丙烷脱氢结焦反应路径具有重要影响,可以直接聚合环化生成多环芳烃,并进一步脱氢生成类石墨化物质;丙炔的加入会降低Pt系催化剂上丙烷脱氢反应的选择性,即除了丙炔自身的结焦反应外,还可能诱发丙烯参与结焦反应中。因此,抑制丙烷脱氢过程的深度脱氢反应,降低催化剂表面丙炔浓度,是抑制丙烷脱氢过程结焦的有效方法。
[Abstract]:Propane dehydrogenation is increasingly becoming an important process for propylene production, but the existing processes still exist problems such as deactivation of catalyst coking. The study of coking composition and mechanism will provide important support for solving this problem. Propargyl is an important intermediate species in the dehydrogenation of propane, which is the starting material of the pyrolysis side reaction and may also have an important influence on the coking reaction. In this study, propargyl was introduced into propane dehydrogenation system to improve the side reaction degree of dehydrogenation process, combined with pyrolysis, Raman, infrared, elemental analysis, thermogravimetric analysis to characterize the properties of coking, and to explore the coking reaction path in the process of propane dehydrogenation. The results show that the coking of propane dehydrogenation over Pt catalyst can be divided into three categories: graphite-like substances, polycyclic aromatic hydrocarbons and long-chain alkanes with continuous distribution of carbon atoms, and a complete coking path for dehydrogenation of propane is derived. It is found that propargene has an important influence on the reaction path of dehydrogenation of propane and can be directly polymerized to form polycyclic aromatic hydrocarbons (PAHs) and further dehydrogenated to form graphitized substances, and that the addition of propargene reduces the selectivity of dehydrogenation of propane over Pt catalysts. Besides the coking reaction of propyne itself, propene may also be involved in the coking reaction. Therefore, it is an effective method to restrain the coking of propane dehydrogenation by inhibiting the deep dehydrogenation of propane and reducing the concentration of propane on the catalyst surface.
【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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