Main Field of Research:

Enhancement of mass transfer in multiphase flows

Experimental investigation of reactive bubbly flows - Influence of boundary layer dynamics on mass transfer and chemical reactions

Reactive Bubbly Flows DFG Priority Programm 1740

  • How does the interaction of the timescales of hydrodynamic mixing, mass transfer and reaction influence the selectivity in a chemical process?
  • Using laser measuring techniques like Particle Image Velocimetry and Laser Induced Fluoresccence to visualize the velocity and concentration fields of reactants, product or side products to understand the interaction of their timescales. 
  • The understanding of the inerlinked local processes can lead to more save, reliable and efficient process control in mulitphase reactors of the next generation.

Characterization of Fine Bubbles for biocatalytic processes

  • Macroscopic aeration can lead to reduced enzyme activity by foaming and induced shear forces.
  • Bubbles with diameters less than 100 μm offer large volume-specific interfacial areas a and therefore high mass transfer rates βLa of the gaseous reactant into the bulk phase.
  • The project is in close collaboration with the Institute of Technical Biocatalysis (ITB) focusing on the application of the achieved findings for biocatalytic processes. 

Transport Processes at fluidic Interphases

  • Hydrodynamics and Mass Transfer across clean and contaminated fluidic interphases at single Taylor bubbles in vertical channels.
  • Using Particle Image Velocimetry and Laser Induced Fluorescence to visualize the local velocity and concentration field.
  • Surface Active Agents (surfactants) adsorb at interfaces and formate layers, which effects the mass transfer across and the slip condition at the interphases. 

Experimental studies on mass transfer and local flow parameters in monoliths, foam structures and structure elements

"Energy efficient chemical processes" - Helmholtz Energy alliance

  • Development of novel structured packings which can optimize the Mass Tranfer und Pressure Loss regarding process efficiency in multiphase reactors 
  • Identifying the geometry parameter field and manufacturing of structure elements
  • Laser optical measurement and calculation of energy specific mass transfer performance for the parameter field

Design & scale up of multiphase reactors

Experimental analysis of crucial model parameters in bubble columns under industrial conditions

  • Scale up & design of bubble column reactors.
  • Most relevant is the specific interfacial area for mass transfer but it is difficult to estimate, which requires advanced measurement methods for process medium and operation conditions
  • Smart design strategy for bubble column reactors with reliable multiscale modeling. 

Large scale bioreactors - insights into a black box

  • Lack of knowledge especially for large scale applications, where the influence of the inhomogeneity of the gas phase is much higher than in small scale reactors.
  • An acrylic glass reactor has been designed and erected on industrial scale (15 000 L).
  • The optical access of this reactor enables us detailed studies on local flow patterns and their influences on mixing and mass transfer
  • Liquids with tailored theology for the substiution of process media to enable opticale measurements (various industrial partners)

Controlling Multiphase Flows for Process Safety

Characterization and prevention of vortices at centrifugal pump intakes

    "SAVE" Safety-relevant Analysis of the Performance of Centrifugal Pumps, Valves and Inlet Geometries, including stress-related Events BMBF-Project: 

  • The occurrence of vortices in cooling water reservoirs poses a high safety risk for the safe operation of cooling systems
  • Vortices lead to entrainment of angular momentum and gas in the cooling pumps which reduces or interrupts the flow of cooling water and damages pump inlets.
  • Investigation of the influences of different parameters on vortex formation, optimization of existing analytical models and design recommendations for the prevention of air entrainment. 

Hydrodynamic Characterization of Deep-Sea Blowouts

  • For the experimental investigation of multiphase flow phenomena under simulated deep-sea conditions several high-pressure facilities have been developed, built and commissioned.
  • Sophisticated measurement technologies such as high-definition camera recording, high-speed Particle Image Velocimetry (PIV) and an endoscopic particle size measurement system from the Sopat GmbH are applied.
  • Close collaboration with various international partners for experimental investigations and modeling.