Background: Microreactors are three-dimensional structures in the micrometer to centimeter range, in which chemical reactions occur to synthesis chemicals, exchange heat or provide energy. Due to the miniaturization the advantages of microreactor technology are better heat and mass transfer, a greater surface-to-volume ratio and no need to scale up reactions. Aside from chemical synthesis micro reactors are frequently used in catalysis research for high throughput catalyst screening and kinetic studies. Furthermore, the recent progress in microelectromechanical systems (MEMS) demands for much smaller and higher energy density electrical power sources such as microcombustors (microburners) because hydrocarbon energy densities are 100 times higher than the state of- the-art lithium-ion batteries. If microcombustors were successfully developed and combined with appropriate energy conversion devices, lighter and/or longer lifetime electrical power sources could be realized.

 

           

CFD simulation of velocity field (middle), product concentration (right) using 80000 cells (left) in single bead reactor (d = 1 mm) applied for high throughput catalyst screening by hte AG


Projects: In the last years, we have been active in the areas of the application of micro reactor development for catalyst screening and catalytic microburners. Since the catalytic structures used in high temperature catalysis are on the sub-millimeter scale, there are synergies between these research projects and our micro reactor activities.  The development of microreactor technology for catalyst screening calls for a clear understanding of the interactions between different reaction chambers in the reactor. It must be ensured that the single reactor chambers do not thermally interact and are filled uniformly. CFD simulations have been used to guide the design and optimization of experimental devices for catalyst screening.
Currently computational tools are applied for the design of microreactors used in hydrocarbon reforming and for the development of micro-devices for combustion.


Collaboration: hte AG, Heidelberg/Germany, K. Maruta (Akita University, Japan), P.D. Ronney (USCLA, USA)


Funding: hte AG, Heidelberg/Germany

 

Further information:

T. Zech, J. Klein, S.A. Schunk, T. Johann, F. Schüth, S. Kleditzsch, O. Deutschmann. Miniaturized Reactor Concepts and Advanced Analysis for Primary Screening in High-Throughput Experimentation. Chapter 25 in High Throughput Analysis: A Tool for Combinatorial Material Science. Kluwer, 2003, 491-523

K. Maruta, K. Takeda, J. Ahn, K. Borer, L. Sitzki, P. D. Ronney, O. Deutschmann. Extinction Limits of Catalytic Combustion in Microchannels. Proc. Combust. Inst. 29 (2002) 957-963

O. Deutschmann. Modellierung von Mikrostrukturreaktoren. DECHEMA-Weiterbildungskurs Mikroverfahrenstechnik, Frankfurt a.M., June 8/9, 2005