Microreactor System Design

TeGeotenhuis, W. E., Wegeng, R. S., VanderWiel, D. P., Whyatt, G. A., ViSWANATHAN, V. V, ScHIELKE, K. P., Sanders, G. B., Peters, T. A., Microreactor system design for NASA in situ propellant production plant on mars, in Proceedings of the 4th International Conference on Microreaction Technology, IMRET 4, pp. 343-3350 (5-9 March 2000), AIChE Topical Conf Proc., Atlanta, USA. 

Fig. la-e. Selected microreactors, a Stainless steel microreactor system designed by Ehrfeld Mikrotechnik. b Glass microreactor (Watts and Haswell 2005). c Stainless steel microreactor of the CYTOS Lab system (http //www.cpc-net.com/cytosls.shtml). d Silicon-based microreactor designed by Jensen (Ratner et al. 2005). e Glass microreactor of the AFRICA System... 

Quiram DJ, Jensen KF (2007) Integrated microreactor system for gas-phase catalytic reactions. 3. Microreactor system design and system automation. Ind Eng Chem Res 46 8319-8335... 

The authors developed a multi-layered microreactor system with a methanol reforma- to supply hydrogen for a small proton exchange membrane fiiel cell (PEMFC) to be used as a power source for portable electronic devices [6]. The microreactor consists of four units (a methanol reformer with catalytic combustor, a carbon monoxide remover, and two vaporizers), and was designed using thermal simulations to establish the rppropriate temperature distribution for each reaction, as shown in Fig. 3. 

As the ability to generate more samples per imit time increases with improvements in the capabilities of combinatorial and microreactor systems, there is a growing need for a faster analytical response. To keep the Development Cycle (react, analyze, handle data, and design next experiment) functioning at a productive rate there is need to characterize samples and convert the corresponding analyhcal data into valuable information. This information will then feed the Design of Experiment part of the cycle. Significant effort has been put into approaches to speed up the ability to analyze samples and this has often been aided by miniaturization of the analytical equipment. 

DARPA (Defense Advanced Research Program Agency) provides additional funding for DuPont/MIT collaborative research effort to prove that a microreactor system can be designed for safe, parallel operation... 

Full factorial designs with M levels can be used for estimating polynomials of order at most M -1. Naturally, these designs are feasible only with very few variables, say maximum 3, and typically for only few levels, say at most 4. For example, a 44 design would contain 256 which would be seldom feasible. However, the recent development in parallel microreactor systems having e.g. 64 simultaneously operating reactors at different conditions can make such designs reasonable. 

FIGURE 42.3 A modular microreactor system for the direct fluorination of ethyl acetoacetate by fluorine gas. The design allows for multiple channels to be supplied from single reservoir sources and a multichannel device to be constructed in a facile manner from a disposable channel plate. (Taken from Chambers, R.D., et al.. Lab on a Chip, 2005, 5 191-198. With permission.)... 

By applying MF techniques, the reaction heat can be controlled by varying the thickness and thermal conductivity of the wall. Geometrical parameters and construction materials are the key selection criteria in designing the microreactor systems, whilst for microsystems which perform chemical reactions, separations, analyses, and sensing devices, the channels, cavities, valves and electrodes all need to be designed and selected properly. 

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