Researchers at Bath University in the UK have developed a new enzymatic process intensification technology that is now being investigated for potential use in accelerating the rate of pharmaceutical enzyme reactions.
Dr Emma Emanuelsson and Dr Darrell Patterson, from the University’s Department of Chemical Engineering, developed the Spinning Cloth Disc Reactor (SCDR). This technology extends the principles of the conventional Spinning Disc Reactor, in that it uses centrifugal forces to allow the spread of a thin film across a spinning horizontal disc; however, the disc has a cloth with immobilised enzyme resting on top of it. The SCDR therefore produces 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 and accelerating the rate of an enzyme reaction.
Dr Patterson said: ‘Our work has shown that this system produces enhanced reaction rates compared with conventional enzyme reaction systems. We found that the conversion and reaction rates in the SCDR were significantly higher than those in a conventional batch stirred tank reactor under comparable conditions. The SCDR was also simple to control.'
Dr Emanuelsson said: ‘Many enzyme reactors suffer from a loss of enzyme activity over many cycles of reaction due to deactivation – and one would perhaps expect this to be the case in a rotating reactor, where enzymes would be deactivated by shear.
‘However, the most exciting result is that the immobilised lipase showed excellent stability to repeat reactions in the SCDR: for the tributyrin system, 80% of the original lipase activity was retained after 15 consecutive runs.’
The team has also demonstrated the robustness of the SCDR to industry-relevant feeds through the successful hydrolysis of different vegetable oils at reaction rates five times higher than other reactors.
Dr Patterson said: ‘We have called this new reactor class “spinning mesh disc reactors”, 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.’
The researchers are now looking to extend the applications to pharmaceutical and biodiesel synthesis reactions.