Fast batch reactor technology: Redefining reaction control & scalability
Philippa B. Cranwell of ConsultaChem and Benjamin J. Deadman of BJ Deadman Consultancy share some results comparing the PI QFlux fast batch reactor to conventional alternatives
Fast batch reactor technology has been explicitly designed for rapid adoption by the pharmaceutical, petrochemical and fine chemical industries. These versatile systems can be considered a half-way house between flow chemistry and traditional batch reactors, giving the excellent thermal and kinetic control offered by flow systems but on the reaction volume comparable with a process-scale reactor.
Optimising thermal control on process scale
Taking a chemical process from laboratory scale to process scale is never simple. Alongside the practical challenges of handling larger quantities of material during scaleup, the physical behaviours of the reaction should also be considered – especially the thermodynamic and kinetic profile.
Thermal control, in particular, is a common headache, during both heating and cooling of reaction mixtures, and can contribute significantly to the time profile for a reaction, which can increase costs and environmental impact. While flow chemistry can offer some answers to the scale-up problem, especially due to the thermal control offered, several challenges limit the mainstream adoption of flow chemistry at production scale.
Existing reactors, processes, services and staff training are often built around the traditional batch mode of product delivery, and installation of a flow set-up may not
Figure 1- Simulated comparison of times to cool DMF from 150 ° C to 20 ° C at different batch vessel scales.
Note: 1,000 L PI QFlux vessel- bold blue line, 10 L conventional batch reactor- red line
be viable, both in terms of cost and operator expertise. In addition, flow chemistry is not necessarily suitable for all processes, for example where solids are used or formed, reaction times are long, or work-up requires several steps or manual operations.
However, there is a third approach. A fast batch reactor, such as the PI QFlux *, can combine the advantages of batch and flow-based methodologies, offering significant gains over traditional process vessels and some flow chemistry set-ups. Key features of the PI QFlux, which was designed and developed by Process Technology Strategic Consultancy( PTSC) with thermodynamic modelling support from the University of Aberdeen, 1 include:
• A larger heated surface area
• Increased heat transfer capability
• Smaller thermal mass of the temperature control fluid
• Wider processing temperature range
• Optimised in-process mixing
• Plug-and-play capabilities
In addition, the PI QFlux requires significantly less energy during operation, and can substantially reduce end-to-end processing times.
Thermal transfer
Heating and cooling reactions on process scale is slow due to the inherent inefficiencies associated
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