Source: Umweltcluster Bayern
The cross-cluster project of the Bavarian Environmental Cluster (UCB) and the top level cluster MAI Carbon of the Carbon Composites e.V. (CCeV) has now announced results. The speakers gave insights on recycling and disposal.
Aircraft, automobile or bicycle – the industries are versatile when it is to be light and stable and carbon fibre reinforced polymers (CFRP) are used. The composite material has an enormous potential for lightweight construction, which is to be used more and more frequently in the future. It is therefore very important to devote a great deal of attention to the question at the end of the life cycle of CFRP. Therefore, CFRP-containing waste streams will increase significantly in the future and new challenges for the recycling industry will arise. Unused recycling potentials and alternative disposal possibilities are central issues for both manufacturers and waste disposal companies.
The MAI UCB project, which was launched in October 2016, between the Bavarian Environmental Cluster (UCB) and the top level cluster MAI Carbon was devoted to issues related to the disposal and recycling of carbon fibre-containing waste. The aim of the project was to identify and elucidate intelligent and sustainable solutions for the recycling and disposal of carbon fibre-containing residues. It was about the development of a sustainable basis, which initiated processes over the duration of the project, which further develops the utilisation of CFRP and anchors it in Bavaria.
Apart from the established pyrolysis numerous new fibre-matrix separation processes are currently being tested. Solvolysis, supercritical water, induction heating and electromagnetic commutation are still in their infancy. If the fibre is successfully separated from the matrix, there are new paths for further processing. Fibres which are preserved in long pieces are processed into tapes, yarns or nonwovens. Short fibres and dusts can be processed by injection moulding. The goal is to use the fibres again and again. Even the shortest fibres can significantly increase the mechanical properties of injection moulding compounds.
CFRP can neither be deposited due to the carbon content nor burned in conventional waste incineration plants because of the stability of the fibre. Tobias Walter presented a solution from AlzChem GmbH at the one-day event at the Technology Center Augsburg (TCA). They tested successfully CFRP waste from raw material for the production of calcium carbide.
Furthermore, the results of the Georgsmarienhütte GmbH were presented, which successfully tested CFRP waste as a primary carbon substitute in steel production. Likewise, the special waste incinerator Indaver also carries out a thermal utilisation of CFRP with great success.
The contributions of the new methods for utilisation of CFRP were accompanied by scientific contributions from RWTH Aachen University and TU Dresden. Mrs. Maria Reiter from Fraunhofer IGCV presented the challenges in the life cycle assessment of CFRP recycling methods. Here, too, it became clear, depending on how and where the material is used, that it can be ecologically sustainable.
In summary, it should be noted that CFRP is a material in development. The current opinion that CFRP is not sustainable is obsolete. The technologies for a sustainable use of CFRP are already in place and are certainly in use. New applications of recycled materials are found almost daily. Decisive will still be the price. The trend continues to show downwards. The theme day “Utilisation of CFRP-containing waste” showed that there are quite marketable business models for disposal and recycling, which, however, must be expanded even more intensively for the mass market.
“For the further success of this material, it will be important that we develop value-adding prerequisites,” Prof. Dr. Volker Warzelhan, Member of the Board of the Carbon Composites e.V.