Continuous Chemical Manufacture with Light (C2ML)

The manufacture of chemicals makes a major contribution to the UK's economy; £10 bn p.a. in the chemicals and £9bn in the pharmaceuticals sectors alone. The recent report of the Chemistry Growth Strategy Group states that 'By 2030, the UK chemical industry will have further reinforced its position as the country's leading manufacturing exporter and enabled the chemistry-using industries to increase their Gross Value Added contribution to the UK economy by 50%' with "smart manufacturing" as one of three priorities in realising their vision.

Our proposal aims to contribute to this smart manufacturing by transforming the way in which continuous photochemistry can be applied to commercial chemical manufacture. There is considerable current academic interest in new photochemical reactions for organic synthesis but how they might be used industrially is usually ignored. Nevertheless the potential of photochemistry in manufacturing is widely recognized if only it could be made scalable and efficient. Traditionally the pharmaceutical and fine chemicals industries have used batch reactors for manufacture, which are difficult to adapt effectively for photochemistry. Therefore, this proposal focuses on continuous reactors which not only permit innovation in design to overcome technical limitations of current photoreactors but also provide a direct route to increased throughput via scale up or scale out.

We will tackle some of the technical and engineering issues inherent in conventional photoreactors. These engineering problems include getting light efficiently into the reactors, build-up of opaque material on transparent surfaces key safety issues, particularly in reactions involving oxidation, as well as cost issues related to low efficiency of many light sources and difficulties of scale up.

Our project proposes to create new engineering approaches to continuous photochemical manufacture of chemicals, which could transform chemical processes and cost. Our proposal addresses key technical/scientific barriers frustrating current commercial use of photochemistry and promises cheaper products in the pharmaceutical, agrochemical and fine chemicals sectors. Our team consists of three investigators with a proven track record of taking chemical processes from laboratory to commercial plant. Between us, we have the expertise needed for success; namely, in photochemistry, continuous organic reactions, manufacturing, mechanical and chemical engineering and process monitoring.

Our Impact Plan is focussed on transferring our research as effectively as possible into chemical manufacture. To achieve this we have assembled an initial group of project partners. They include the Chemistry Innovation Knowledge Transfer Network (CIKTN), Britest, equipment manufacturers Uniqsis and HEL, LED specialist and supplier Enlumo, pharmaceutical companies Sanofi, Novartis, AstraZeneca and GSK, fine chemical manufacturer Thomas Swan & Co and agrochemical company Syngenta.

The manufacture of organic chemicals is unusual because usually there is more than one route to making a particular compound. Historically, speed rather than cost has been the most important factor in determining the route for making a compound in research labs. This means that the whole process may have to be redesigned before the scale of production can be increased and the compound manufactured cost effectively in a commercial production plant. There are a variety of reasons for this including the difficulty of using some reagents in large quantities, generation of unacceptable volumes of waste, and difficulties in controlling exotherms on a large scale. In particular, the pharmaceutical industry often uses different routes to produce the same compound at different stages of drug development. Therefore, there would be significant savings in cost and time if one could use the same process along the entire length of the chemical manufacturing pipeline; for discovery, for development and for commercial manufacture.

In this context, continuous reactions have a distinct advantage that more material can be produced merely by running the reactor for longer and throughput can be increased either by building larger reactors (scale up) or running several reactors in parallel (scale out). Furthermore, our project is timely because there is already considerable interest in continuous processing in the pharmaceutical and fine chemicals sectors. This means that we will be pursuing our pathway to impact with an industry that is already sympathetic to the concept of continuous reactions.