MCEC Members: Maike Baltussen (TU/e) and Ward van der Stam (UU)

In the second phase of MCEC, we have welcomed many new members. In this rubric we will introduce them to you. 

Maike Baltussen (TU/e)

… is an Assistant Professor at the research group Multiscale Modelling of Multiphase Flows of Prof. Hans Kuipers in Eindhoven.

Photo: Vincent van den Hoogen

What do you do?

I’m specializing in simulating gas-liquid and gas-liquid-solid flows using mainly Direct Numerical Simulations. Within MCEC, I work on the flow in trickle beds and riser reactors. Besides, we are working on the formation of droplets in a spray dryer. Finally, soon a project on water electrolysis is starting.

A new sub-grid scale method
Besides these projects, my personal focus is trying to investigate the mass transfer from single bubbles. I have been developing a new sub-grid scale method, which enables us to simulate high Schmidt numbers. Currently I’m trying to extend this to multiple bubbles and bubbles interacting with structures.

Length and time scales
The main challenge in performing numerical simulations without rigorous assumptions is covering all the relevant length and time scales. For example, the boundary layer in mass transfer is much smaller than the hydrodynamic boundary layer (about 10-30 times). To resolve it, we have to create a higher resolution, which will result in a high grid count or very slow simulation (waiting for several months).

Future collaboration
The next step in multi-scale modelling of gas-liquid and gas-liquid-solid models is to optimize the code even further. This will enable us to model more realistic systems. In addition, the current models are only including simplified kinetics. To create a more realistic model, we have to include the realistic kinetics.

To include these, I think collaboration is of high importance. Currently I am collaborating with Ivo Filot, using his microkinetic modelling to include the essential kinetics in our reactor models. Combining this with the heat and mass transfer in our models, will enable us to make a realistic prediction of a real reactor.

Read more about Maike Baltussen on the website of TU/e

Ward van der Stam (UU)

… is tenure track Assistant Professor at Utrecht University in the Inorganic Chemistry and Catalysis research group of Prof. Bert Weckhuysen.

What do you do?
My research at Utrecht University focuses on the combination of colloidal chemistry and in situ spectroscopy/diffraction techniques in order to understand and steer the electrocatalytic CO2 reduction reaction.

Colloidal nanomaterials
The overarching goal of my research is to rationally design electrocatalyst nanoparticles that selectively convert CO2 into value-added base chemicals and fuels, such as long-chain hydrocarbons and alcohols. For example, 16 products are known to evolve from copper electrocatalysts, and I want to understand why certain products form and how we can selectively make a specific product. I personally think that colloidal nanomaterials offer interesting opportunities to achieve this goal, since the size, shape and composition of these nanomaterials can be tailored with atomic precision, and these parameters heavily influence the outcome of the CO2 reduction reaction.

In situ electrochemical cells
Specific challenges of this research involve the design and construction of in situ electrochemical cells that are compatible with different characterization techniques (e.g. infrared and X-ray radiation) while ensuring the electrocatalytic performance (e.g. activity and selectivity of the CO2 reduction reaction). Currently, our team of PhD-students, postdocs and technicians is developing electrochemical cells for in situ surface-sensitive and time-resolved Raman spectroscopy, (Grazing Incidence) X-ray Scattering and Diffraction and X-ray Absorption Spectroscopy measurements, and future developments will focus on surface-sensitive Infrared Spectroscopy and fluorescence spectroscopy.

Future developments and collaboration
I think MCEC is an excellent environment for this research to take the next step and understand the CO2 reduction reaction in detail and valorize industrial CO2 waste streams. I look forward to many fruitful collaborations within MCEC, since the interdisciplinary background present within the community allows for out-of-the-box research and innovative science.

Read more about Ward van der Stam on the website of ICC UU