Design of an Industrial-Size Airlift Loop Redox Cycle (ALRC) Reactor for Catalytic Alcohol Oxidation and Catalyst Reactivation

Abstract

An industrial-size airlift loop redox cycle (ALRC) reactor has been designed for the selective oxidation of alcohols. Selective catalytic alcohol oxidation can produce valuable products for fine chemistry applications. However, the catalyst undergoes a factor of 10 loss in activity within hours as a result of overoxidation. The catalyst can be reactivated by contacting it with a reducing environment. This modeling and reactor design study shows that the ALRC reactor is a suitable option for achieving alternating contact of the catalyst with a reducing and oxidizing environment. It is shown that the superficial slurry velocity and the inlet partial pressure of oxygen mainly determine the reactor performance. A reactor design is developed on the basis of kinetic, hydrodynamic, and economic considerations, in which the catalyst activity remains high during its presence in the reactor. Finally, the ALRC reactor is compared with a stirred-tank reactor process involving alternating gas feed streams. It is shown that the ALRC reactor is much cheaper in terms of reactor operation than the stirred-tank reactor process and, thus, this type of reactor can feasibly be used in the selective oxidation of alcohols while maintaining a high catalyst activity.

Optimal Design of a Multifunctional Reactor for Catalytic Oxidation of Glucose with Fast Catalyst Deactivation

“…Sketch of tanks-in-series model (right) linking hydrodynamics with kinetics that occur in the individual sections of continuously operating three-phase gas-lift reactor (left). Kluytmans, et al (2003) proposed application of GLR for reaction similar to the model one. To design the target three-phase GLR that would suit the reaction of Glc oxidation over the Pd/C catalyst, we constructed GLR mathematical model (see Gogová & Hanika (2009,c) ) www.intechopen.com Dynamic Modelling 220 that is presented and applied in the following text.…”

“…The GLR model proposed employs tanks-in-series mixing model sketched in Figure 6 to combine hydrodynamics of a real GLR (Bello, et al (1984), Blažej, et al (2004, Sikula, et al (2007), , Sikula & Markoš (2008) ) and the kinetics of the model reaction from Section 1.1. This GLR model is much simpler and a bit more realistic than that of Kluytmans, et al (2003) who employed axial dispersion mixing model with hydrodynamics measured in small-scale 2D bubblecolumn reactor and considered intra-particle diffusion.…”

Model‐Aided Design of a Three‐Phase Gas‐Lift Reactor for Oxidation Accompanied by Catalyst Reversible Deactivation

“…Oxidation of polyol (methyl-a-D-glucopyranoside) over a supported platinum catalyst was studied by Kluytmans et al [2]. The reaction is one of the synthetic steps in vitamin C production.…”

“…It was shown in our previous papers [1,3] that the aldehydic group of glucose plays a positive role in the catalyst reactivation and its overall performance. Authors of the paper cited above [2] proposed application of a three-phase GLR suitable for the substrate oxidation in the riser and the catalyst reactivation in the downcomer sections.…”

“…The GLR model proposed employs a tanks-in-series mix-ing model to combine the hydrodynamics of a real GLR [4][5][6][7][8][9][10][11][12] and the kinetics of glucose oxidation by air over the palladium catalyst [1]. This GLR model is much simpler and a bit more realistic than that of Kluymans et al [2], who employed an axial dispersion mixing model with hydrodynamics measured in a small-scale 2D bubble column reactor and considered intraparticle diffusion.…”