Green Recycling And re-manufacturing of Carbon fibre composites for a circular Economy (GRACE)

Lead Research Organisation: University of Manchester
Department Name: Materials

Abstract

Carbon fibre reinforced polymers (CFRP), with their superior combination of stiffness, strength, thermal stability, light weight and corrosion resistance have been leading contenders in various applications, ranging from aerospace to ground transportation, construction industries to sporting goods. The global transition of aircraft with composite architecture is estimated to contribute 15%-20% of industry CO2 reduction targets by 2050, due to the lightweight design. Strengthening of structural members using CFRP is one of the most commonly used methods in the construction industry to prolong the life of existing structures.

An increasingly significant amount of CFRP composite waste is being generated as large quantities of such materials starting life in the 1970's applications reach their 50-year service life. As these materials are thermoset, their decomposition and recycling are an urgent worldwide challenge. The existing recycling techniques generally require complicated processes, expensive facilities or toxic chemicals. Because the existing recycling methods need shredding or milling of the CFRP composite before recycling, the recycled carbon fibres have low commercial values. Moreover, the existing recycling methods focus on recovering fibres and the resin remains waste.

This project will develop international leading technologies of recovering carbon fibres from end-of-service-life (EOSL) carbon fibre reinforced polymer (CFRP) composites. The recovering process will be operated under ambient temperature and pressure. It will be zero waste and the recovered fibres will maintain the original dimensions and strengths. The transformative recycling methodology of this project will be based on the award-winning technology, the Electrically driven Hetero-catalytic Decomposition (EHD) method, patented by the applicants. The reclaimed fibres will be fabricated into continuous fibre yarns. Potential cost savings of more than 20%-83% and energy savings of 82%-98% have been predicted for using recycling technologies.

In addition to using recycled fibres, this project will incorporate low environmental impact bio-resins in CFRP composites and demonstrate their applications in aviation and construction industries through thorough testing and modelling. A cradle to grave Life Cycle Assessment (LCA) will be carried out to provide data for optimisation of resources and minimisation of environmental impacts. This collaborative project will take advantage of supplementary international leading expertise from the UK and Chinese partners to deliver transformative technologies to harness the full value of end of service life CFRP composites for a circular economy. The project team will use their wide networks of contacts to actively engage with key stakeholders in the entire supply chain of the composite industry in both the UK and China to ensure the widest interest in and take up of the outcome of the project.

Planned Impact

This project will develop technologies to transform the end of service life CFRP composites so as to fully recover the fibres and resin. Re-use of carbon fibres and introduction of bio-resin will deliver cost avoidance, cost reduction and reduced resource footprint and lower environmental impact. Discussions with our industrial stakeholders have confirmed that we are breaking new scientific ground whilst demonstrating also an understanding of the many challenges of reclaiming intact long carbon fibres from composite wastes. They are also optimistic of our proposed methods of remanufacturing composites from recycled carbon fibres and bio-resins for future applications (see letters of support). The broad scope of GRACE means there is a wide range of beneficiaries and stakeholders who will be impacted throughout this project and beyond.

The anticipated industrial and societal benefits and their beneficiaries include:
- Waste management companies: skill upcycling from value destruction and waste generation to value retention and resources creation, enhanced reputation and job opportunities; new commercial activities enabling direct material flow from wastes to new products
- CFRP manufacturers: high value remanufacture with reduced material usage and reduced life cycle cost of products.
- CFRP Suppliers: reduced cost of carbon fibres and enhanced sustainability reputation through reusing materials and products in new products.
- Bio-based resin supplier: opportunities of application of their materials in the aviation and construction industry.
- Product manufacturers: reduction in construction cost through high value material (carbon fibres) reuse and reduced manufacturing activities; low-carbon manufacture using bio-based low carbon resin; The products cover a wide range of industries such as aviation, vehicle, sport equipment, construction and etc.
- UK and China manufacturing: new manufacturing jobs in innovative technologies of recycling and remanufacturing of composites.
- Product designers and cross-sector professionals: 'new' low impact products, knowledge and skills and enhanced international leading expertise.
- Regional government: reduction of material downcycling and life cycle costs; improved resource productivity and enhanced competitiveness; creation of new industry sectors, ventures, jobs and employment.
- Regulators: guidance on reuse of reclaimed materials and products - uptaking and upscaling of innovation.
- Central government and wider policy environment: new and improved method of composite reuse.
- UK and China society: reduced environmental impacts, security and resilience of composite material supply.

Publications

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Soutis C (2019) How green composite materials could benefit aircraft construction in Science China Technological Sciences