Abstract

Flow Chemistry: Process Intensification through Microreactor Technology

Igor Plazl, Professor, University of Ljubljana

A substantial amount of publications each year demonstrate how through the application of microprocess engineering significant benefits can be obtained concerning product yield, purity and time needed for chemical and biochemical transformations, compared to the equivalent bulk reactions [1]. The microreactor technology demonstrated the advantages of microfluidic devices for very efficient performing of chemical and biochemical processes at controlled and repeatable conditions. Recently, the new concepts such as continuous processing, flow chemistry, high-throughput screening, and process intensification, have been established in order to open novel pathways in process design and engineering. The process intensification provides insights into the different scales at which process intensification can be employed. Stankiewicz and Moulijn [2] defined process intensification as the development of novel and sustainable equipment that compared to the existing state-of-the-art, produces dramatic process improvements related to equipment sizes, waste production, and other factors. No doubt, process intensification through microreactor applications clearly hold the potential to revolutionize (bio)chemical synthesis, but scarce articles demonstrate specific suggestions for possible replacement of existent industrial processes. On the other hand, a number of highly innovative and systematic approaches, protocols, tools, and strategies has currently been developed in both industry and academia, all to minimize the gap between research and industry, and to define a smooth transfer of lab-on-a-chip to the industrial environment. To meet these challenges, we must advance the field from (bio)catalyst discovery to (bio)catalytic microprocess design. This will require not only a new level of understanding of reaction mechanisms and transport phenomena at the micro scale, but also the development of relevant computational tools [3].In this work, the microscale (bio)process development based on scale-up/numbering-up concept in combination with modeling-based optimization is presented. The main features of microscale systems are reflected in fluid dynamics, therefore the understanding of fundamental mechanisms involved in fluid flow characteristics at the micro scale is essential since their behaviour affects the transport phenomena and microfluidic applications. Theoretical description of transport phenomena and the kinetics at the micro scale is discussed and illustrated on the cases of a lattice Boltzmann simulations for flow distribution in the packed bed microreactor “between two-plates” and the biocatalytic enzyme surface reaction.