Industrial microreactor process synthesis

Hessel, V., Lob, P., and Lowe, H. (2008) Industrial microreactor process development up to production, in Microreactors in Organic Synthesis and Catalysis (ed. Th. Wirth), Wiley-VCH Verlag GmbH, Weinheim, pp. 211-275. 

Currently, after each step in the synthesis process, a sample is analyzed to approve or reject the operation. Not only is this inefficient for the industry in general, this is also a stumbling block for a rapid scale-up. Controls and measurements of the process need to be accomplished in situ, which is again an issue that requires the chemists and chemical engineers to work together toward a solution. It may, in fact, involve lab-on-a-chip technologies and microreactors that were presented by other speakers in this workshop. 

With MRT the synthesis of increased amounts of a compound is reduced to a simple question of the rate of throughput. Once a synthesis has been optimized in a microreactor, small-scale production will be only a matter of numbering up the microreactor systems or a problem of scaling out the microreactor [22]. Not surprisingly, chemists in process development departments, particularly in the pharmaceutical industry, recognized MRT as a versatile tool for their daily work as it enabled fast and low-cost kilogram-scale synthesis, e.g. for early clinical studies, in an... 

As mentioned above, microreactors are expected as small-size industrial reactors for nanoparticle synthesis. A number of reports on nanoparticle synthesis in a microreactor have been published following the reports of De Mello s group and Maeda s group in 2002. Among them, the most dominant and currently being employed in nanoparticle synthesis using a microreactor is the nucleation-growth model. Therefore, this section mainly focuses on this process. 

The work presented here is based on the development at University of Regensburg by Ulbrich et td. [55]. It utilizes the novel process windows offered by continuous-flow microreactor technology [56]. A conventional industrial batch synthesis of the product 4-hydroxycyclopentanone, which is an important intermediate for pharmaceutical building blocks, was described previously [57]. In a recent publication, Nettekoven et al. [58] described an investigation of a synthetic route for five-membered ring structures used as pharmaceutical synthetic building blocks based on furfuryl alcohol... 

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