Clariant advances microreactors for pharma synthesis

This unit, called the Clariant Competence Centre for Microreactor Technology (C3MRT), will develop microreactor technology as a means of increasing efficiency, improving safety and reducing the costs of pharmaceutical synthesis.

In addition, C3MRT will assist in the use of microreactor technology as a process development tool for syntheses that will be carried out in standard batch-type equipment.

Microreactors take the form of miniaturised flow channels ranging between several micrometres and 1 millimetre in size, that are connected in parallel to handle the large-volume requirements of speciality chemical producers. But compared to large-volume batch reactors, these microreactors allow an increased transfer of material and heat, thanks to their much larger surface area, and their modular set-up allows the process to be adapted quickly to the varying requirements of different chemical reactions.

And because reactions can take place at higher temperatures, this should reduce the amount of reagents and catalysts used, providing an opportunity for cost savings.

This set-up also makes screening of reaction parameters - such as temperature, residence time, concentration - quicker and easier. Also, due to their small reaction volume, microreactors are viewed as inherently safe installations, so they could be used to house explosive or hazardous reactions that would be impossible in batch reactors.

Until recently, the use of microreactors has largely been limited to research and development, as experience in scaling it up to a larger capacity has been lacking. Clariant has been developing the technology for the specialty chemicals sector since the late 1990s.

"Microreactor technology can offer significant advantages in commercial pharmaceutical applications that require rapid scale-up, those that have safety issues at traditional scales, as well as in reactions that require an uncommonly high level of temperature, concentration and dosing control or very high purity,"​ according to Ralf Pfirmann, global director, pharmaceutical market management for Clariant Pharmaceuticals.

He noted that the technology is already providing commercial results in niche applications at Clariant, and that the use of microreactors in pharmaceutical synthesis has the potential to deliver molecules "at much better yields, with higher selectivities and with economics heretofore not possible."​

However, there are still a number of challenges to overcome to refine the use of microreactors in synthesis. For example, they can be affected by clogging and corrosion, particularly if solid phases are needed in a reaction, and their tiny bores means cleaning can be difficult, especially if films form within the microreactor vessels. Also, there can be significant changes in the behaviour of reactions once the process is scaled up to a commercial level.

The new unit will be based in Clariant's Frankfurt site, which includes two pilot plants and a dedicated laboratory. C3MRT was inaugurated in January.

Christian Wille, who is responsible for technical development at C3MRT, said: "While microreactor technology will not replace all of today's batch process technologies, we see its development in niches."​

He estimated that in total these niches could account for 15 to 20 per cent of all synthetic processes.

Other companies developing microreactors for fine chemicals synthesis include BASF, Ehrfield Microtechnik, CPC Systems and Bartels Microtechnik.