Sustainable Recycling of Wind Turbine Blades: Glass Fiber Recovery through CFB Technology

This study investigates the application of circulating fluidized bed (CFB) oxidative pyrolysis for the recovery of glass fibers from decommissioned wind turbine blades (WTB). XPS analysis revealed that increasing oxidative pyrolysis temperature led to a progressive reduction in C-C bonds and an increase in polar surface groups such as C-OH and O─C═O, indicating enhanced surface oxidation and degradation of the carbon backbone. SEM images showed that surface morphology deteriorated at high temperatures, with increased cracking and contamination, whereas moderate oxidative pyrolysis conditions preserved smoother surfaces. Samples combusted with a temperature range of 600-700 °C (R2) yielded the most favorable balance between surface functionalization and structural integrity, as evidenced by the retention of key Si-C and Si-O-Si frameworks. R2 exhibited the highest tensile strength (0.295 GPa) and strength recovery rate (33.5%) among recycled samples. In contrast, lower temperatures showed signs of incomplete matrix decomposition, while higher temperatures underwent excessive thermal damage, impairing their mechanical performance. These findings highlight the critical role of oxidative pyrolysis temperature in governing the physicochemical and mechanical properties of recycled glass fibers and demonstrate that a controlled CFB process can enable the recovery of high-quality fibers suitable for reuse.