REACTOR TECHNOLOGY with large-scale material processing, and in some cases the heating or cooling process can take longer than the reaction itself. This also requires substantial energy input, increasing both costs and environmental impact.
Under plant conditions, the performance of a PI QFlux was compared with a conventional process-scale reactor by heating 1,000 L of water from 5 ° C to 95 ° C. 2 Physical testing of the PI QFlux was performed by Kobelco Eco Solutions of Japan.
When the input temperature was 170 ° C, the water took 93 minutes to reach 95 ° C using a conventional heating jacket alone. When using the PI QFlux, where heat was exchanged through both the jacket and baffle, the water only took 25 minutes to reach the target temperature, a 73 % reduction in process time.
This was attributed to increased heat transfer performance from the jacket, additional heat transfer performance from the baffle and because, unlike a glass-lined jacket, the baffle heat differential is not restricted to protect the lining.
Reactor equivalencies
Reactor vessel size has a substantial impact upon heat transfer, and therefore rate of heating and cooling of the bulk. The enhanced thermal design of the PI QFlux system circumvents these issues, especially during cooling. During a simulated study that considered reactor size and the time required to cool a batch of DMF, it was revealed that the PI QFlux system surpassed the conventional approach. 2
In this experiment, a series of batch reactor vessels ranging from 1 L to 1000 L were simulated to cool the DMF from 150 ° C to 20 ° C. 2 Overall, the time taken to cool the reactor increased from 13 minutes for the 1 L vessel, to 27 minutes for the 10 L vessel, and 126 minutes for the 1000 L batch vessel( Figure 1).
When a simulation of the PI QFlux system – which holds 1000 L – was included, the performance was similar to that of a 10 L conventional batch vessel, requiring only 33 minutes: fast batch technology can safely manage the thermal risk of transitioning from large-lab scale to mini-pilot, and even production, scale.
Faster heating
This faster reaction heating also means that reaction lag-time, i. e. the time taken to reach the activation temperature of the system, is minimised. This is exemplified using a simple, irreversible bimolecular chemical reaction 1, where A and B react to give product P, which can be modelled using the Arrhenius equation and thus used to derive the rate equation 2.2
Using a computer-based simulation, an isothermal reaction was modelled that, at 110 ° C, took 65 minutes to reach 90 % conversion. Undertaking this same reaction in a conventional reactor, the time taken to reach 90 % conversion was 107 minutes, whereas when using of the PI QFlux fast batch reactor, 90 % conversion only took 79 minutes – a saving of nearly 30 minutes.
In both cases, the time required to heat the reactor was included, which is where the biggest reductions in the time required are made: the benefits of fast batch are most pronounced when the time to complete a reaction is short, because heating and cooling are more efficient due to the reactor set-up.
Unsurprisingly, the faster and more efficient heating by the PI QFlux system results in higher simulated initial rates of reaction, with maximum rates reached in a very short timeframe( Figure 2). 2 This rate then drops quickly as the concentrations of A and B reduce. Conversely, in the conventional reactor the peak in reaction rate is slower but broader, as A and B are consumed less quickly.
In both cases, during prolonged reactions simulated over 6 hours concentration becomes the dominant effect, with the total
Figure 2- Simulated reaction rate & conversion vs. time for PI QFlux( left) & conventional batch( right) reactor
NOV / DEC 2026 SPECCHEMONLINE. COM
59