Microreactors are one of the most talked about innovations in the process development laboratory in the last decade. In spite of widespread publications industrial adoption can be sometimes slow. R&D Teams struggle to justify return on investment and here we try to provide some tips that have helped our customers select the best chemistry scenarios to deploy a microreactor in.
- Highly Exothermic reactions: Typically, as a reactor becomes larger the surface area to volume ratio decreases. As a result, it is exceedingly difficult to conduct reactions which have large exotherms in conventional reactors. Our Amar microreactors are an excellent option to conduct such reactions due to multiple reasons:
- Large heat transfer surface areas
- Safety impact is limited due to small reactant holdups
- Toxic or corrosive reagents: In Pharma or specialty chemicals R&D teams can be wary to use synthesis that include corrosive, toxic or pyrophoric reagents. Microreactors are a safe option since in the worst case scenario very limited exposures would happen. For synthesis using low LD50 value chemicals always consider a flow synthesis in a microreactor due to enhanced safety. Talk to our experts at Amar to find out exotic MOC options such as Hastealloy for your reaction requirements.
- Process intensification: Customers can be disappointed due to the high costs of microreactors relative to throughput (kilos per day) especially in production scenarios. One mistake we see customers make is to use the same T or P conditions that they have been using in batch reactors in the plant. Microreactors are usually capable of withstanding much more aggressive T and P conditions. Such conditions can give faster reactions and hence justify the higher costs of a microreactor per unit volume. Be willing to experiment to find the best T and P for selectivity and throughput and often this will lead to more aggressing operating points of T and P.
- Batch to continuous conversion: Often the first part of this process is to evaluate reaction kinetics. Microreactors can be an excellent way to collect such data rapidly without wasting expensive reagents. Furthermore, due to higher mixing and heat transfer it is easier to obtain inherent reaction kinetics and not get misleading results due to heat transfer limits or mass transfer limits
- Lab scale Synthesis of new molecules: In initial stages of new molecules or impurities milligram or microgram quantities are often sufficient. But in a conventional lab synthesis larger quantities must be made and this wastes resources. A cascading synthesis in flow mode with microreactors can very often be the perfect match for such demands.
- Prioritizing intermolecular reactions versus an intramolecular product: Some chemical synthesis have competing intermolecular versus intramolecular products. In conventional macro scale reactor processes it becomes impossible to get the intermolecular product at high selectivity since the kinetics favours the intramolecular product. However since microreactors have low mixing distances they can often be used to tune selectivity towards the desired intermolecular product.
This should provide customers some food for thought about use cases where microreactors would be a great match for their projects. Do talk to our experts at Amar for additional assistance in deciding whether a microreactor or a conventional reactor would work best for their requirements.
