Microreaction Systems

H., Richter, T., Storz, M., Wole, A., WoRZ, O., Breysse, J., High temperature HCN generation in an integrated Microreaction system, in Ehreeld, W. (Ed.), Microreaction Technology 3rd International Conference on Microreaction Technol-ogy, Proc. of IMRET 3, pp. 152-164, Springer-Verlag, Berlin (2000). 

Taking into account these findings, a microreaction system has been developed by loLiTec Ionic Liquid Technologies GmbH Co to improve mass and heat transfer. The producfion capacity of the currently running system is about 0.5kg/h with a purity >99%. 

The microreaction system and operation were described previously (2). Reactions of 5 jul pulses of o-ethyltoluene (280 ml (NTP)/min He passing over 0.057 gram catalyst) were measured in the catalyst initial activity region prior to extensive deactivation. Catalysts were pretreated for 15.5 hours at 538°C in 40 ml (NTP)/min He. 

Figure 13 Modular microreaction system consisting of functional elements for reactions and unit operations arranged on a base plate. The cube-shaped modules of stainless steel with built-in microstructures have a side length of 25 mm and can be operated at pressures up to 100 bar. (Source Ehrfeld Mikrotechnik.)... 

Essential progress is to be expected from the introduction of so-called modular microreaction systems. The system developed by Ehrfeld Mikrotechnik comprises single functional elements for reactions, unit operations, transport,... 

Kestenbaum, H., Lange de Olivera, A., Schmidt, W., Schuth, F., Ehrfeld, W., Gebauer K., Lowe, H., Richter T., Silver-catalyzed oxidation of ethylene to ethylene oxide in a microreaction system, Ind. Eng. Chem. Res. 2000, 41, 710-719. 

A family of table-top microreaction systems named mikroSyn is provided by MiKroglas Chemtech (Figure 4.26) [77]. The basic system has a size of 700 mm x 70 mm x 330 mm and a weight of 30 kg. It can be equipped with two rotary pumps, one gear pump, valves and pressure and temperature sensors. The reactor itself is interchangeable with all reactor modules provided by Mikroglas Chemtec. 

Figure 4.26 Photograph of the basic mikroSyn microreaction system [77],...

Reactor 14 [R 14] EM Modular Microreaction System (Ehrfeld Mikrotechnik)... 

Figure4.30 Scheme of EM Modular Microreaction System for performing a reaction between aryl halides and vinyl compounds [83] (by courtesy of Ehrfeld Mikrotechnik BTS GmbH).

The parameters windows of the automated microreaction system AuMpRes are given in Table 4.9. These specifications allow the operation of most liquid reactions [108],... 

The Fraunhofer Alliance Modular Microreaction System (FAMOS) is currently working on a micro reaction simulation toolkit (Figure 4.82) with special attention to micro-scale phenomena [124], The virtual toolkit comes with a physical micro reaction toolkit. The MicroSim software reflects the process by considering reaction conditions and reactor geometries. Of course, this approach on the other hand limits the software to the dimensions and geometries of the reactors supplied with the physical toolkit. 

FAMOS - Fraunhofer Alliance Modular Microreaction System - Virtual Toolkit, http //www.microreaction-technology.info,... 

Dietrich, T., Freitag, A., Scholz, R., Microreactors and microreaction systems for development and production, in Proceedings of the 27th International Exhibition-Congress on Chemical Engineering, Environmental Protection and Biotechnology, ACHEMA (19-24 May 2003), DECHEMA, Frankfurt, 2003, 19. 

Dietrich, T. R., Freitag, A., Scholz, R., Microreactors and microreaction systems... 

Ferstl, W., Loebbecke, S., Antes, J., Krause, H., Haeberl, M., Schmaiz, D., Muntermann, H., Grund, M., Steckenborn, A., Lohf, A., Hassel, S., Bayer, T., Leipprand, I., Development of an automated microreaction system with integrated sensorics for process screening and production, Chem. Eng. 2004,... 

Microreactor technology has developed to such an extent that a wide variety of microreactor components, e.g. micropumps, mixers, reaction chambers, heat exchangers, separators and complete integrated microreaction systems with process control units have been fabricated using the appropriate microfabrication process and materials that are suitable for specific applications. 

Integrated microreaction systems for single reactions Single reaction with several (unit) operations — System with several components in fixed sheets... 

Even more complex systems will be given by integrated microreaction systems for multiple-step reactions. They will be composed of flexible sheets which may be divided into classes each representing a homologous series of components. Thus, similar to the series of flasks with variable sizes of 25, 50,... 

Fig. 8. Integrated microreaction system containing mixing units and heat exchangers a Integrated system in photoetchable glass made by photolithography and wet etching, b Detail of an integrated system in a special alloy made by micro spark erosion (EDM-grinding)...

Yoshida and coworkers also developed a microreaction system for cation pool-initiated polymerization [62]. Significant control of the molecular weight distribution (Mw/Mn) was achieved when N-acyliminium ion-initiated polymerization of butyl vinyl ether was carried out in a microflow system (an IMM micromixer and a microtube reactor). Initiator and monomer were mixed using a micromixer, which was connected to a microtube reactor for the propagation step. The polymerization reaction was quenched by an amine in a second micromixer. The tighter molecular weight distribution (Mw/M = 1.14) in the microflow system compared with that of the batch system (Mw/M > 2) was attributed to the very rapid mixing and precise control of the polymerization temperature in the microflow system. 

Another example in which biocatalysis is combined with analysis is the system reported by Honda et al. [436]. A microreaction system, consisting of an enzyme-immobilized microreactor, for optical resolution of racemic amino acids was devel-... 

A maximum yield of80-85% was obtained at 4 s residence time and a temperature of 50 °C by microreaction system processing [27,28], The use of ordinary lab processing with standard lab glassware yielded only 25%. The continuous industrial process had a yield of 80-85% the former employed with semibatch industrial process gave 70% yield. The temperature and the residence time of industrial and microreactor continuous processing were identical. 

In discussing microreaction systems, it is helpful to first distinguish the characteristic size of a microreactor in comparison with conventional scale reactors. Two different definitions of the term microreactor are commonly used in the literature. The first defines any reactor that is an order of magnitude or more smaller than its conventional scale coimterpart as a microreactor. For example, an industrial reforming reactor might be 10,000-100,000 L in volume. Using this first definition, a 1 L reforming reactor could be considered a microreactor. This definition is not very useful as it... 

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