Experts develop faster enzyme reactor technology

Dr Emma Emanuelsson and Dr Darrell Patterson developed the ’Spinning Cloth Disc Reactor’ (SCDR) at the university’s Department of Chemical Engineering.

Based on extended principles of the conventional Spinning Disc Reactor (SDR), the SCDR uses centrifugal forces to allow the spread of a thin film across a spinning horizontal disc. Though, this disc has a cloth with immobilised enzyme resting on top of it.

“Our work has shown that this system produces enhanced reaction rates compared to conventional systems

Dr Darrell Patterson

This allowed the SCDR to produce a flow of thin film both on top of, as well as through the enzyme-immobilised cloth, providing a large interfacial surface area for the reaction.

“Our work has shown that this system produces enhanced reaction rates compared to conventional enzyme reaction systems. Our initial work has been on the conversion of a simple oil system (tributyrin hydrolysis), which shows us if the reactor could be used practically for the treatment of oily wastewaters for example,” Patterson said.

“We found that the conversion and reaction rates in the SCDR were significantly higher than that in a conventional batch stirred tank reactor under comparable conditions,” he added.

Many enzyme reactors suffer from a loss of enzyme activity over many cycles of reaction due to deactivation - and you would perhaps expect this to be the case in a rotating reactor, where enzymes would be deactivated by shear, Emanuelsson explained.

“However, the most exciting result is that the immobilised lipase showed excellent stability to repeat reactions in the SCDR: for the tributyrin system, 80 per cent of the original lipase activity was retained after 15 consecutive runs,” she said.

Meanwhile, a residence time distribution and flow analysis study showed that the SCDR is not quite like other rotating reactors - such as conventional spinning disc reactors and rotating packed bed reactors.

“Our results have shown that the SCDR is a separate class of spinning disc-type reactor for process intensification. We have called this new reactor class ’spinning mesh disc reactors’ (SMDRs), which enables any type of mesh (i.e. not just cloths) with an unbound top surface on a spinning disc to be included within this new reactor classification.

“Overall, our results indicate that the SCDR is an innovative, superior and robust technology for enhancing enzyme reactions, taking enzyme reactors beyond the current state-of-the-art. This concept can readily be extended to other enzyme-catalysed reactions, where enhanced mass transfer and enzyme stability is needed,” Patterson added.