Electrochemical Recycling of Carbon Fiber Composite Wind Turbine Components

This work addresses the need for technologies to recycle wind turbine blades. Wind energy is one of the fastest growing energy sources. As wind energy deployment increases, so too is the quantity of waste from wind turbine blade decommissioning, projected to hit 43.4M tons by 2050. Wind turbine blades are made from difficult-to-recycle composites (including carbon fiber composites) and the majority of decommissioned blades are currently landfilled. Landfilling is environmentally unsustainable and increasingly financially and politically untenable as the amount of blade waste grows. A process for recycling carbon fiber composites from end-of-life blades is being developed that will provide an economical and environmentally sustainable alternative to landfilling. In Phase I, the technical feasibility of this recycling approach was demonstrated by recovering carbon fiber with properties on par with virgin carbon fiber and re-using the carbon fiber in second-generation composite manufacturing. In Phase II, this recycling technology will be refined to achieve the performance, economic, and environmental metrics needed for an in-field pilot-scale demonstration during Phase III. In Phase I, this technology was shown to recover carbon fiber which retained 100% of the mechanical strength of virgin carbon fiber. Carbon fiber recovery was scaled to quantities needed for composite manufacturing; manufacturing of a second-generation polypropylene composite was demonstrated. Technoeconomic analysis showed this recycling technology recovers carbon fiber at a price point ($16/kg fiber) that is cost-competitive with other recycling approaches ($18-25/kg) and significantly lower than virgin carbon fiber manufacturing ($33-66/kg). Lifecycle analysis showed a significantly lower global warming potential (2kg CO2eq/kg) and energy demand (12MJ/kg) than virgin carbon fiber manufacturing (24kg CO2eq/kg, 100-900MJ/kg) and other recycling technologies (3-5kg CO2eq/kg, 67-69MJ/kg). In Phase II, the recycling technology will be optimized to recover fiber that achieves performance benchmarks identified by commercial composite manufacturers and costs needed for breakthrough into large volume markets ($2.2/kg). The ability to manufacture second-generation composites with properties on par with virgin composites will be demonstrated. Mechanical deconstruction procedures will be developed that recover high-quality composite feedstocks from end-of-life blades. By end of Phase II, the recycling technology will be ready for an in-field pilot-scale demonstration. This recycling technology will recover a high-quality, low-cost recycled carbon fiber that can be used to manufacture composites with properties on par with virgin composites. These high-performance, low-cost recycled composites will benefit industries that use large quantities of composites (e.g., aerospace, automotive, wind, sporting goods, boating).