Micro reaction technology

Selectivity (individual impurity) and optical purity of the batch and micro-reaction technology (MRT) processes for (S)-2-acetyl tetrahydro ran synthesis... 

Micro-reaction technology can be one of the tools that process intensification may use [5]. Hence chemical micro processing and process intensification have a share, where the former supplies devices for the latter concept or purpose. However, both chemical micro processing and process intensification also cover imique aspects that the other field does not comprise. 

Accordingly, it is valid to claim the joint onset of micro-reaction technology in 1995 and to try to name those who were the pathfinders in this development (see, e.g., [3] for a description of such an opinion). Regarding the birth of micro-reaction... 

A similar overview of German activities in 1998 is provided in [65]. The German working party on micro-reaction technology is presented, a federal funding program is introduced, and three top-priority research projects are presented. They show the activities at the edge of acceptance by industry. 

There is common agreement that with the aid of micro reactors, process development can be speeded up considerably [5]. First industrial examples on the implementation of micro-reaction technology for pilot-scale and production seem to con-... 

The main achievement of Schwalbe et al. is to have initiated such considerations in micro-reaction technology, known in conventional chemistry for decades, and to have pointed out the theoretical value of such reaction mechanism-based organic micro-reactor processing [81],... 

Micro-reaction technology has just left its infancy and started commercialization. Consequently, we do not know about the social response to micro reactors in general, i.e. the micro-reactor control circuif in the sense outlined above has not yet developed, but we do know something of the response of chemical industry and customers to what the micro-reactor offers. 

Concerning such user-supplier relationships, see also [102] for IMM s view on the role of strategic alliances in the field of micro-reaction technology. 

Fine-chemical companies have definitely shown interest in micro-reaction technology (see also the commitment in [137]) and have formed their own task forces for this purpose. The increasing number of patents is further proof of the beginning commercial use of micro reactors (see, e.g., [318-321]). 

Relationship of and Difference between of PI and Micro-reaction Technology 14... 

The LCA methodology has been used by Krahsch and Kreisel to investigate the pros and cons of micro-reaction technology at the stage of process development. The motivation for this study was the question whether ecological improvements can be expected for the chosen model reaction performed in the micro-structured device Cytos produced by CPC Systems GmbH, Germany. Such improvements were the premise for the construction of a continuously operated pilot plant based on Cytos micro-reactors. 

Watts P, Wiles C (2007) Recent advances in synthetic micro reaction technology. Chem Commun 5 443 167... 

In specialty chemicals, the majority of plants are multi-product or multipurpose plants operated in batch mode. Only a relatively small proportion of products is produced in continuous production plants. This might change however, once current development activities ongoing in the area of flexible, continuous production technology for small production volumes (micro-reaction technology) find their way into industrial production systems.13 So far, this technology is mostly employed in pilot-plant - scale production trials, but further improvements are to be expected in the near future. 

The theoretical foundation for this kind of analysis was, as mentioned, originally laid by Taylor and Aris with their dispersion theory in circular tubes. Recent contributions in this area have transferred their approach to micro-reaction technology. Gobby et al. [94] studied, in 1999, a reaction in a catalytic wall micro-reactor, applying the eigenvalue method for a vertically averaged one-dimensional solution under isothermal and non-isothermal conditions. Dispersion in etched microchannels has been examined [95], and a comparison of electro-osmotic flow to pressure-driven flow in micro-channels given by Locascio et al. in 2001 [96]. 

Manufacturing information systems for real-time process control in the lab and for efficient statistical process control, as well as the right number of lab trials, limits information losses between the plant and the labs. Parallel synthesis, such as units with online analytics in the lab, and the use of new technologies such as Micro Reaction Technology developed by Clariant and a few other companies for application in production mean a step change in reproducibility. 

Plants used in micro reaction technology span a wide range of geometrical scales and operational limits. Also a variety of application modes such as commercial, research or training purposes are found. Supplier-specific set-ups exist which intend... 

Modularity is only needed where micro reaction technology is really demanded i.e. for micro fluidic modules. The motto of the developers is thus in analogy with the credo of the authors of this book, not to make microstructured devices as small as possible as many tools as necessary, not as many as possible . 

Heatric claims to have developed a robust and renewable technology to apply catalyst coats to the passages within a PCR [163]. This coating has to be executed after the diffusion bonding but the coating procedure is not described. Such a development would certainly be a milestone in micro reaction technology as the standard wash-coat methods are usually applied to free accessible surfaces and not to closed channels. 

MRT MS MSR Micro reaction technology Mass spectrometry Methanol steam reforming... 

Furthermore, in the synthesis of fine chemicals typical process technology considerations, for example space-time-yield, are less important than for bulk chemicals. Because of the relatively small production outputs batch reactors are the most common apparatus in which to perform the synthesis. New chances in the field of fine chemistry may be offered by micro-reaction technology. Microstruc-tured systems can be used to improve heat transfer which may be critical for highly exothermic reactions and, furthermore, they may be also useful in reactions where fast mixing of components is recommended. 

In 2004 Clariant set up a new centre for the development of microreactor technology in Frankfurt, Germany, called the Clariant Competence Center for Micro Reaction Technology. Its facilities include two microreactor pilot plants and a dedicated laboratory. Clariant says that by using parallel microreactor modules makes it possible to turn out kilogram or even ton quantities of a product [B-46],... 

The synthetic processes of traditional chemical industry vill be strongly affected by new opportunities offered by biotechnology and process intensification (such as micro-reaction technology). The fiexible integration of inherently safe process technologies w ith small holding volumes w ill be a key to success for future products. 

Although the field of micro reaction technology has provided overwhelming evidence to show that reactions are more efficient and products can be synthesized in higher purity compared with conventional batch procedures, trace metal contamination of the resulting compounds can still present a problem. 

Limitations of the platform are related to the material properties of PDMS for example, chemicals which the elastomer is not inert to cannot be processed, and elevated temperatures such as in micro-reaction technology are not feasible. Also for the implementation of applications in the field of point-of-care diagnostics, where a handheld device is often required, the LSI platform seems not to be beneficial at the moment. Thereto external pressure sources and valves would have to be downsized to a smaller footprint, which is of course technically feasible, but the costs would be higher in comparison to other platform concepts. However, as a first step towards downsizing the liquid control equipment, the use of a Braille system was successfully demonstrated [143]. 

Dietzsch, E. Honicke, D. Fichtner, M. Schubert, K. WeiBmeier, G. IMRET 4 4th International Conference of Micro Reaction Technology Topical Conference Proceedings, AIChE, Spring National Meeting, Atlanta, GA, USA, March 5-9, 2000, American Institute of Chemical Engineers, Indianapolis, IN, USA, p 89. 

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