Recovery of Glass Fiber Reinforcement from Retired Wind Turbine Blades for Recycled Composite Materials

By 2050 43,400,000 metric tons of cumulative wind turbine blade waste is expected to exist and continue growing at 2,000,000 metric tons/year globally. Even in the near term, wind turbine blade waste generation is expected to approach 1,000,000 metric tons/year by 2029. In short, the amount of wind turbine blade waste needing disposal is growing rapidly while the status quo option of landfilling, aside from being environmentally unsustainable, will progressively become politically and financially untenable. An economically and environmentally sustainable solution is needed for the handling of waste composite wind blade materials. As the glass fiber reinforced polymer composites used for wind blade construction are heavily used across the wider composites industry (i.e., +90% of all fiber reinforced polymer composites are made with glass fiber), such a recovery technology would have vast implications for the numerous other industrial sectors (e.g., aerospace, automotive, marine) that regularly utilize these materials in their products. In this project, a novel pyrolysis-based composite recycling method will be further developed to convert the organic components of wind turbine blades into energy-rich fuels / petrochemicals while recovering the embedded glass fiber reinforcement free of all char and other contaminants and with sufficiently retained mechanical properties for reuse as polymer reinforcement. Entire wind blades will be size reduced and fed into the prototype pilot reactor system with the output products (i.e., glass fiber, fuels, etc.) analyzed for yield and quality. In Phase I of this project, the recovery process was scaled in the lab from gram to kilogram scale quantities and the resulting reclaimed glass fiber used to produce a demonstration polypropylene composite. The recovered fiber was visibly indistinguishable from virgin material and possessed similar tensile stiffness. The recovered fiber polypropylene composite similarly exhibited comparable mechanical performance to polypropylene reinforced with virgin glass fiber. These results indicate that, if the recovery process can be further scaled, it can recover glass fiber with mechanical properties appropriate for reuse in 2nd life generation composites. In Phase II of this project, the team will solve scaling and other technical challenges that emerged during Phase I development, research and validate blade size reduction techniques and design and validate a prototype pilot reactor system for processing metric tons of wind turbine blade waste into recovered glass fiber and . Data collected from prototype development operation will be used to refine and validate a process techno-economic model being developed in tandem with the project technical work. At Phase II completion the composite recovery technology will have both the business case and physical process validated for private investment and full scale deployment in Phase III. Recovered glass fiber from this technology can be readily used in the manufacture discontinuous fiber composites (e.g., injection molding thermoplastics, molding compounds, other nonwovens) converting vast quantities of plastic waste into feedstocks for new value-added products. For example, the glass fiber from wind turbine blades, instead of going into landfills, would one day be usable for making new automotive composites to produce lighter weight, fuel efficient vehicles.