Progressing Flow Chemistry through the Additive Manufacturing of Novel Functionalised Systems

Project background (identification of the problem and its importance and relevance to sustainability)

Flow chemistry has demonstrated improvements over traditional batch type chemistry systems. Improved mass and heat transfer allows more effective and efficient production of chemical products, and the continuous nature inherently improves safety by minimising operator exposure. Flow systems are industrially utilised for processes ranging from petrochemicals to bulk manufacture of specialty chemicals such as nanoparticles showing the versatility of the technology. However, initial experimental design and screening is predominantly performed with lab-based batch equipment.

While small scale flow systems are available commercially for research, they typically use standardised components that lack flexibility. Additive Manufacturing (AM) can be utilised to develop more flexible systems for a range of chemical synthesis including heterogeneous catalysis, photo and electrochemistry. Developments in AM has enabled increasing design freedom for printed parts. Novel methodologies have overcome restrictions such as the requirement for structural supports. Polymers have extensive use in the fabrication of microfluidic systems due to their controllable properties such as shape fidelity and applicability to different 3D printing methods. However limitations around chemical compatibility, temperature tolerance, material leeching and air-permeability are yet to be suitably addressed.

Additive manufacturing addresses the accessibility to flow systems by allowing them to be produced and trialled on site. This enables researchers to more readily trial novel reactions in a more sustainable way and also has the potential to provide access to more complicated reactor setups to less developed research locations. Solving the issue around typical AM materials while also utilising the benefits of AM is the focus of this project.

Proposed solution and methodology

Glass is a desirable material for use in AM due to its chemical inertness, high transparency and physical tolerances. Conventional 3D printing techniques employ layer by layer formation of materials that suffer inter-layer deformities. More novel techniques utilise volumetric prints, producing glass structures of suitable quality for use as tubular flow paths. Work will be undertaken to identify and assess suitable methodologies for producing flow systems using AM glass structures.

Further development of flow systems utilises PAT (process analytical techniques) and computerised systems for machine learning for rapid process optimisation. AM enables the integration of sensors into components as they are fabricated, minimising production time and enabling novel analytical techniques. Additional functionalisation can integrate reactive components such as supported catalysts for uses such as enzymatic reactions. Development of a flow system utilising glass and the functionalisation enabled through AM will expand the applications of flow chemistry. The inherent sustainability of flow systems will further benefit from ease of reaction monitoring through integrated components and reactive functionality will open the door to novel synthesis techniques.

Relevant analysis techniques will be used to assess AM glass transparency, purity and structural strength. Developed systems will also be assessed through reaction trials to monitor performance with results from all analysis leading into further development and optimisation.

This CDT will deliver impact aligned to the following agendas:

People
A2P will provide over 60 PhD graduates with the skill sets required to deliver innovative sustainable products and processes into the UK chemicals manufacturing industry. A2P will inspire and develop leaders who will:
- understand the needs of industrial end-users;
- embed sustainability across a range of sectors; and
- catalyse the transition to a more productive and resilient UK economy.

Economy
A2P will promote a step change towards a circular economy that embraces resilience and efficiency in terms of atoms and energy. The benefits of adopting more sustainable design principles and smarter production are clear. For example, the global production of active pharmaceutical ingredients (APIs) has been estimated at 65,000-100,000 tonnes per annum. The scale of associated waste is > 10 million tonnes per annum with a disposal cost of more than £15 billion. Consequently, even a modest efficiency increase by applying new, more sustainable chemical processes would deliver substantial economic savings and environmental wins. A2P will seek and deliver systematic gains across all sectors of the chemicals manufacturing industry. Our goals of providing cross-scale training in chemical sciences with economic and life- cycle awareness will drive uptake of sustainable best practice in UK industry, leading to improved economic competitiveness.

Knowledge
This CDT will deliver significant new knowledge in the development of more sustainable processes and products. It will integrate the philosophy of sustainability with catalysis, synthetic methodology, process engineering, and scale-up. Critical concepts such as energy/resource efficiency, life cycle analysis, recycling, and sustainability metrics will become seamlessly joined to what is considered a 'normal' approach to new molecular products. This knowledge and experience will be shared through publications, conferences and other engagement activities. A2P partners will provide efficient routes to market ensuring the efficient translation and transferal of new technologies is realised, ensuring impact is achieved.

Society
The chemistry-using industries manufacture a rich portfolio of products that are critical in maintaining a high quality of life in the UK. A2P will provide highly trained people and new knowledge to develop smarter, better products, whilst increasing the efficiency and sustainability of chemicals manufacture.
To amplify the impacts of our CDT, effective public engagement and technology transfer will become crucially important. As a general comment, 'sustainability' styled research is often regarded in a positive light by society, however, the science that underpins its effective implementation is often poorly appreciated. The University of Nottingham has developed an effective communication portfolio (with dedicated outreach staff) to tackle this issue. In addition to more traditional routes of scientific communication and dissemination, A2P will develop a portfolio of engagement and outreach activities including blogs, webpages, public outreach events, and contribution of material to our award-winning YouTube channel, www.periodicvideos.com.

A2P will build on our successful Sustainable Chemicals and Processes Industry Forum (SCIF), which will provide entry to networks with a wide range of chemical science end-users (spanning multinationals through to speciality SMEs), policy makers and regulators. We will share new scientific developments and best practice with leaders in these areas, to help realise the full impact of our CDT. Annual showcase events will provide a forum where knowledge may be disseminated to partners, we will broaden these events to include participants from thematically linked CDTs from across the UK, we will build on our track record of delivering hi-impact inter-CDT events with complementary centres hosted by the Universities of Bath and Bristol.