Advancing continuous crystallisation technologies
Traditional batch technologies for manufacturing fine chemicals are inherently wasteful, due to difficulties in consistently meeting product specification. For every kilo of active pharmaceutical ingredient harvested, up to 200 kilos of waste can be produced.
Since the production of most ingredients involves crystallisation, better control of crystal purity and size makes a major difference to companies’ efficiency and profit. Hence the importance of research led by Heriot-Watt Professor Xiongwei Ni that pinpointed shortcomings of traditional batch reactors and crystallisers.
It was already known that delivering a consistent product specification required control of cooling and uniform mixing and that what worked in the lab became problematic at industrial scale. Prof Ni’s research focused on understanding the science of achieving uniform mixing whatever the batch size. The ‘continuous oscillatory baffled reactor and crystalliser’ technology that led on from this research combined uniform mixing with precise temperature control at all scales of production.
The reactor/crystalliser was taken to market through Heriot-Watt spinout NiTech Solutions Ltd. It has since generated very substantial sales for pharmaceutical companies. It fits easily into an existing building, avoiding the high start-up costs of conventional, larger, alternatives. The reaction is some 40 times faster, product quality is higher, and, with the ability to continuously monitor and control the reaction, reject rate is zero.
NiTech’s technology was the inspiration for, and now underpins the Continuous Manufacture and Crystallisation (CMAC) consortium which has attracted over £60M investment, much of it from major industrial partners GSK, AstraZeneca and Novartis. CMAC is now the largest centre globally for continuous crystallisation. It is focused on helping industry evaluate and trial leading-edge solutions to accelerate the introduction of new process-intensification technologies.
Thanks to Heriot-Watt research, continuous reaction and crystallisation feature prominently in the chemical and pharmaceutical industries’ drives aimed at more efficient use of reagents, solvents and energy, while minimising waste.