Eco-efficiency evaluation on the recycling of carbon fibre reinforced polymer

Carbon fibre reinforced polymer (CFRP) is widely used in aerospace applications, and will increasingly be used in automotive applications into the future. A large quantity of composites waste is therefore generated from manufacturing processes and end-of-life vehicles. Recovering value from CFRP waste can help to address the high cost and environmental burden of producing carbon fibres. Life cycle costing and environmental assessment methods are applied in this study to quantify the financial and environmental impacts of alternative waste CFRP treatment routes. Thus, we formed a set of combined indicators including total cost and global warming potential (GWP). Three CFRP waste treatment routes are evaluated: landfilling; incineration with energy recovery; and mechanical recycling. Fibre recovered by mechanical recycling output is evaluated as a substitute for glass fibre and carbon fibre, depending on fibre properties and application. In the absence of regulation, landfill represents the least-cost CFRP waste treatment of those considered. When Landfill Tax legislation is included in the analysis, incineration is preferred from a cost perspective. However, relative to landfill, incineration is associated with increased greenhouse gas emissions: carbon released from CFRP during combustion exceeds CO₂ emissions savings from displacing UK electricity and/or heat generation. The financial and environmental performance of mechanical recycling for recycling of CFRP is heavily dependent on the materials they can displace. On-going development of carbon fibre recovery technologies and composite manufacturing techniques using recycled carbon fibres will lead to improved material properties and is therefore critical to ensuring financial viability and environmental benefit of CFRP recycling.