The technology consists of a reaction cylinder at the bottom of which are three rotating discs. When gas is fed into the system through the floor of the cylinder the bubbles are sheared off by the high-speed flow of the mixture.
Lead developer Marco Meeuwse told in-Pharmtechnologist.com that, unlike in stirred tank systems, the close proximity of the discs to the reactor wall in the new design means energy used for rotation is dissipated in a smaller volume.
“This,” he continued “leads to the formation of much smaller gas bubbles, and thus gas-liquid interfacial area, and a high degree of turbulence, leading to high gas-liquid and liquid-solid mass transfer coefficients.
“Overall this leads to high mass transfer rates, much higher than in conventional reactors,” Meeuwse continued, and claimed that this can be a factor of 10 times higher than in traditional stirred tank reaction systems.
Advantages
Higher transfer rates allow for smaller reaction volumes, which would be a significant advantage for potentially dangerous processes such as hydrogenation according to Meeuwse.
He also said that, depending on a reaction’s kinetics and mechanism, a higher mass transfer rate can increase the selectivity, potentially making separation easier and reducing raw material consumption.
“The reactor can be scaled up by scaling out by stacking several rotor-stator units in series. The same reactor type could therefore be used for small scale as well as for large scale production, which could reduce the time to market.”
Next steps
Now that proof of principal and the scale up potential of the new approach has been established, Meeuwse and his colleagues are assessing its impact on other reaction characteristics, for example, heat transfer.
“We are in close cooperation with a large equipment manufacturer, who is interested in commercialising the reactor. An innovation and design process for a reactor like this normally takes a few extra years, so it will still take some time before the first commercial units will be built, although we already have a reactor which can cope with industrial conditions, which can be used for proof of principle study of reaction cases.”