Dynamic Characterization of Trickle-Bed Reactors (Industry-University Cooperative Project)

滴流床反应器广泛用于各种石油加工系统，如加氢脱硫、脱氮、脱金属、加氢处理以及涉及加氢和氧化反应的化学品的制造。反应器由直径为0.08 cm至0.32 cm的固体催化剂颗粒组成，填充在垂直管状反应器中，具有共流（下行或上行）或逆流气/液流动配置。由于其流型接近塞流，单位体积液体的催化剂负荷高，能量耗散低，并且在生产率和操作条件上具有灵活性，因此得到了广泛的应用。滴流床反应器的潜力从未得到充分利用，特别是在化学加工和特种产品制造方面。这是因为人们对滴床中的现象还不完全了解，而且与滴床设计相关的困难超过了其他类型的反应堆。虽然在石油加工过程中，为某些已知原料扩大滴床反应器的规模已经成为一门艺术，对于以前不存在专门知识的饲料和工艺，从小型实验室装置放大的滴流床性能的“先验”预测仍然被认为是非常危险的，根本没有做。阻碍滴床放大问题的主要原因是对颗粒尺度不完全接触的认识不足以及工业滴床床层尺度上的总液体分布不均匀。精确的设计前提是了解局部液固接触（即颗粒的外部和内部湿润程度）和颗粒外部液体流动的非理想性（即旁路，流动中的径向不均匀性，与塞流的其他偏差等）。示踪剂方法提供了一种评估反应器尺度和颗粒尺度非理想性的工具。提出的研究范围是研究在识别和解耦上述影响的示踪数据解释的新方法。提出的项目背后的关键思想是使用多种示踪剂，即使用非吸附和吸附（非挥发性）示踪剂来表征反应器中液相的行为。pi想要表明，通过使用这种技术可以获得额外的信息，这些信息允许反应器尺度和颗粒尺度的非理想性解耦。

Trickle-bed reactors are used in a wide variety of petroleum processing systems such as hydrodesulfurization, denitrogenation, demetallization, hydrotreating and in manufacture of chemicals involving hydrogenation and oxidation reactions. The reactors consist of solid catalyst pellets, 0.08 cm to 0.32 cm in diameter, packed into a vertical tubular reactor with cocurrent (downflow or upflow) or countercurrent gas/liquid flow configurations. They are widely used because their flow pattern approaches plug flow, high catalyst loading per unit volume of the liquid is possible, energy dissipation is low, and there is flexibility in production rate and operating conditions. The potential of trickle-bed reactors has never been fully utilized especially in chemical processing and manufacture of specialty products. This is due to the fact that the phenomena in trickle-beds are incompletely understood, and the difficulties which are associated with trickle-bed design exceed those encountered with other reactor types. While scaleup of trickle-bed reactors in petroleum processing for certain types of known feeds is well established as an art, "a priori" prediction of trickle-bed performance of scaleup from small laboratory units for feeds and processes for which previous know-how does not exist is still considered very risky and is simply not done. The scaleup problem in trickle-beds is hampered mainly by inadequate knowledge of both the particle scale incomplete contacting as well as by the gross liquid maldistribution on the bed scale in industrial trickle-beds. Accurate design presupposes the knowledge of local liquid-solid contacting (i.e. of the extent of external and internal wetting of the particles) and of the non-idealities of flow of the liquid external to particles (i.e., bypassing, radial non-uniformity in flow, other deviations from plug flow, etc.). Tracer methods offer a tool for evaluating both of these reactor scale and particle scale non-idealities. It is the scope of the proposed research to investigate new methods of tracer data interpretation in identification and decoupling of the above effects. The key idea behind the proposed project is the use of multiple tracers i.e. the use of non-adsorbing and adsorbing (non- volatile) tracers to characterize the behavior of the liquid phase in a reactor. The PIs want to show that additional information, which allows the decoupling of the reactor scale and particle scale non-idealities, can be obtained by the use of this technique.