• Oscillating droplet reactor - towards kinetic investigations in heterogeneous catalysis on a droplet scale

    Torsten Klement, Schirin Hanf, Fabian Wolff, Norbert Kockmann, Stephan A. Schunk, Thorsten Röder

    In this work we present a new concept of a millistructured capillary reactor setup for contactless kinetic measurements via in-line Raman spectroscopy for three phase reactions in single slugs. With this setup, it is possible to decouple the residence time from the volumetric flow and the reactor length. Catalysts palladium supported on carbon, in the form of Pd nano-particles on graphite fibres as well as in the form of a fixed bed catalysts as particulates of porous carbon, were utilised. A 3D-printed catalyst holder was designed to integrate the catalyst powder with a fixed bed in the capillary. The proof of concept was demonstrated using two test reactions, namely the hydrogenation of nitrobenzene and cinnamaldehyde. Multiple measurements were carried out and a good reproducibility was achieved, which lays the foundation for the application of this 3-phase oscillating droplet reactor as a tool for assessing kinetics with respect to heterogeneously catalysed three phase reactions.

    • Link
    • DOI: 10.1039/D0RE00466A

    • Reaction Chemistry & Engineering

  • Continuous diameter increase reactor – a reactor concept for maximizing productivity by a controlled diameter extension

    Marcus Hafner, Fabian Wolff, Thorsten Röder

    This paper presents a novel theoretical approach for maximizing productivity in microreactors by a controlled extension of the tube diameter. A one-dimensional numeric model was developed where the tube diameter increases based on the reaction heat to achieve a constant temperature throughout the reactor length. Through this approach, a basic plug flow reactor model for mass and heat transfer was used with an integrated algorithm for a controlled diameter extension. A parametric study was performed to ensure safe operating conditions concerning thermal runaway. The results show an increase in productivity of approximately 42% for the fictional second-order test reaction.

    • Link
    • DOI: 10.1007/s41981-022-00224-2

    • Journal of Flow Chemistry


  • Device and method for anylizing three-phase reactions

    Michael Dejmek, Schirin Hanf, Patricia Löser, Stephan A. Schunk, Thorsen Röder, Torsten Klement, Fabian Wolff

    The invention relates to an apparatus for investigating reactions comprising a liquid phase and a gaseous phase in the presence of a solid catalyst (13), comprising a channel (9) in which the solid catalyst (13) is accommodated, a drop generator (7) for supplying at least one individual drop (31) into the channel (9), and an analysis unit (11) or measuring unit, characterized in that a gas connection for supplying the gas phase is further comprised and the channel (9) has a hydraulic diameter of 0.1 to 5 mm at the beginning and at the end of the solid catalyst (13), respectively, and a pump unit is comprised with which the at least one single droplet (31) can be moved through the solid catalyst (13) in an oscillating manner. The invention further relates to a method for investigating a three-phase reaction in such an apparatus.