Microscale technology and biocatalytic processes (Part 2*): scale-up case of surface enzyme-catalyzed biotransformation
Microreactor technology (MRT) has advantages, which can be efficiently used in the large scale manufacturing of chemicals. For economical and practical reasons, single microreactor unit has to be optimized before numbering up. In this paper, we carry out preliminary calculations for the selection of the optimal device dimensions for the case study of enzyme-catalysed reaction. We find that the space-time-yield for the plate stacked reactors with wall-immobilized enzymes, can be improved by the use of channels with smaller height. However, for the large scale applications, enzyme immobilization on the high surface material, such as on a layer of the nanosprings, is essential.
In the first part of the article we outlined some of the scale-up approaches of microreactor technology (MRT) devices. It is important to develop an efficient single microreactor unit, before the final numbering-up (1). We present preliminary selection of the optimal dimensions of a single reactor, by reviewing the process constrains, while maintaining the total throughput and the conversion the same. In order to clearly demonstrate the scale-up of MRT, a catalysed biochemical reaction process performed at the uniform reaction temperature is used for the case study. Enzymes can be immobilized in a porous media to achieve higher stability, easy separation from liquid and high enzyme loading. However, in the case of enzymes with a high turnover number, the reaction can suffer from intraparticle diffusion limitations and from the inaccessibility of active sites. One solution is the deposition of enzymes on the high specific surface area material which allows transport of reagents through convection. An example of this material is a nanospring layer (2). For the large scale production, a device with high surface to volume ratio should be used to ...