Holistic life cycle assessment and economic analysis of CFRP and CMC from renewable resources

In view of dwindling fossil resources and political challenges, independence from them is crucial. However, high-performance materials such as carbon fiber-reinforced plastics (CFRP) and carbon fiber-based ceramic matrix composites (CMC) are currently based on petroleum-based, non-renewable raw materials. A more sustainable production of these materials requires both an improvement of existing products with regard to their eco-balance and the development of innovative, resource-saving CFRP and CMC solutions. This can be driven forward through the targeted promotion of basic knowledge and initial impetus for sustainable manufacturing processes.

In Germany, the production, processing and use of carbon fiber-reinforced plastics and fiber ceramics for new applications is predominantly carried out by small and medium-sized enterprises (SMEs). However, these often face high investment hurdles in the area of sustainability. The aim of the project is to provide these companies with a sound basis for overcoming these obstacles. To this end, promising manufacturing processes for regenerative carbon fiber and ceramic composites are identified, implemented and comprehensively evaluated in terms of their performance and sustainability.

Both CFRP and ceramic composites are based on petroleum-based carbon fibers, which is why CFRP can be considered a precursor to CMC materials. A key approach to reducing environmental impacts therefore lies in the development of alternative, renewable raw materials for carbon fiber production.

In the CU GreenCeramic project, promising approaches are identified through literature research and expert interviews and evaluated in close consultation with the project advisory committee (pA). The alternative process routes for the production of renewable carbon fibers and the starting material acrylonitrile (ACN) required for manufacturing are evaluated and analyzed in terms of their life cycle assessment in order to work with industry to identify those with the greatest potential for future application.

In addition, the project also focuses on the production of CMC applications from recycled carbon fiber (rCF) semi-finished products. For this purpose, rCF nonwovens are used, which are adapted to the specific requirements. The nonwovens are produced using wet laid technology.

Another focus is on the development of sustainable matrix materials for CFRP and CMC ceramics. To this end, both partially bio-based and 100% bio-based resin systems are being developed, tested, and evaluated in terms of their sustainability.