Contact

Dr. Markus Schubert

m.schubertAthzdr.de
Phone: +49 351 260 2627

Rotating fixed bed reactor for process intensification of multiphase reactions

Conversion and selectivity of heterogeneous catalyzed hydrogenation and oxidation processes in trickle bed reactors are often narrowed by the limited access of the gaseous phase to the solid catalysts. In addition, maldistributions of gas and the liquid phase reduce the utilization of the catalyst packing. The inclined rotating fixed bed is a novel reactor concept for process intensification, inducing beneficial flow patterns, which ensures catalyst wetting intermittency by superimposed reactor inclination and rotation.



Within the framework of a DFG-funded project, tomographic imaging was applied to identify beneficial process windows of the inclined rotating reactor prototype at which the stratified flow regime evolves, which significantly enhances the gas mass transfer. Under these conditions, reaction studies for the hydrogenation of alpha-methylstyrene revealed a twofold increase of the conversion compared to the conventional upright trickle-bed reactor. Complementary computational fluid dynamics simulations based on a 3D model utilizing a modified permeability approach were successfully applied to predict the flow patterns.



The aim of the second funding period is the development of an application-oriented and predictive reactor model for the description of the space-time-yield of various inclined reactor designs with stratified flow in order to fully utilize the intensification potential and to identify optimal process conditions. For that purpose, a two-phase Eulerian-Eulerian CFD model for the description of the hydrodynamics of the stratified flow regime will be coupled with a heterogeneous continuum mass transport model. The model will be validated by means of a comprehensive experimental database on the influence of operating parameters and material properties.

Funding

Deutsche Forschungsgemeinschaft (DFG, SCHU 2421/2-1, SCHU 2421/2-3)

References

  • K. Subramanian, M. Winkler, H.-U. Härting, M. Schubert
    Prediction of flow patterns of rotating inclined reactors by using a modified permeability approach
    Chemical Engineering and Technology 39, 11, 2077-2086 (2016)
  • H.-U. Härting, R. Lange, M. Schubert
    Multiphase flow modelling in moderately rotating inclined porous media
    Canadian Journal of Chemical Engineering 94, 10, 1995-2003 (2016)
  • H.-U. Härting, R. Lange, F. Larachi, M. Schubert
    A novel inclined rotating tubular fixed bed reactor concept for enhancement of reaction rates and adjustment of flow regimes
    Chemical Engineering Journal 281, 931-944 (2015)
  • H.-U. Härting, R. Berger, R. Lange, F. Larachi, M. Schubert
    Liquid backmixing in an inclined rotating tubular fixed bed reactor - Augmenting liquid residence time via flow regime adjustment
    Chemical Engineering and Processing: Process Intensification 94, 2-10 (2015)
  • H.-U. Härting, A. Bieberle, R. Lange, F. Larachi, M. Schubert
    Hydrodynamics of co-current two-phase flow in an inclined rotating tubular fixed bed reactor - Wetting intermittency via periodic catalyst immersion
    Chemical Engineering Science 128, 147-158 (2015)