Composites waste, projected to soar to a staggering 683,000 metric tons annually by 2050 in Europe alone, poses a challenge for the industry. With its diverse composition of glass fibers, additives, and thermosetting resins, composite waste demands innovative solutions to mitigate its environmental impact. Here, Kim Sjödahl, senior vice president for technology and sustainability at specialist composites manufacturer Exel Composites, explores the pioneering initiatives shaping the future of composites manufacturing.
What’s the Problem with Composite Materials?
Composite materials are difficult to recycle due to their complex structure. Composites vary in chemical compositions and physical properties, and consist of fibers, such as glass or carbon, embedded in a resin matrix. This heterogeneity makes separation difficult, especially considering the strong bonding between the components, and risks material damage.
Due to a lack of infrastructure and technology available for large-scale composite recycling, finding sustainable, cost-effective disposal methods has remained challenging. That is, however, until December 2020 when the Finnish Plastics Industries Federation, the Ministry of the Environment, Kuusakoski Oy, Finnsementti Oy and seven composite industry companies including Exel Composites, secured funding for an innovative initiative.
The KiMuRa Project and Cement Production
The KiMuRa project spearheads the development of a circular economy model for composite products by implementing open-loop recycling techniques to transform composite waste into cement through co-processing. Manufacturers supply glass fiber composite waste for processing. This co-processing method involves the shredding and crushing of the waste to break the composites down into more manageable pieces.
Subsequently, the prepared composite waste is introduced into a cement kiln, where each constituent element of the glass contributes to the formation of cement clinker, an essential intermediary in cement production. Additionally, co-processing enables energy recovery, as the organic components in the resins generate heat energy during combustion, reducing the reliance on fossil fuels in cement kiln operations.
reliance on fossil fuels
Cement clinker formation conventionally relies on two primary materials: limestone (calcium carbonate) and aluminum silicate clays like kaolinite. These materials react to produce alite, the key component of cement clinker. In the co-processing method, glass fibers serve as a replacement for both limestone and kaolinite. Glass fiber’s composition, approximately 50 per cent silicon dioxide, up to 15 per cent aluminum oxide, and 20 per cent calcium oxide, make it an effective alternative for both substrates in cement clinker production.
Towards Sustainable Waste Management
The co-processing of composite waste provides a step in the right direction of sustainable waste management, diverting it away from energy recovery and/or landfills and generates zero ash residue. It also reduces the need for mining and extraction operations of raw materials, such as limestone and kaolinite.
Composite waste in Europe is on course to reach 683,000 metric tons annually by 2050. Exel Composites, alongside industry leaders and partners, leads the charge in innovative recycling solutions. The KiMuRa project exemplifies this commitment, repurposing composite waste into valuable resources while reducing environmental impact. Despite challenges like limited scrap availability and cost concerns, the journey towards a zero-landfill future persists.
Join us in revolutionizing composite recycling and building a greener future. Visit www.exelcomposites.com/sustainability to learn how you could take part in sustainability initiatives.
