Experimental and numerical investigation of the pyrolysis behavior of decommissioned wind turbine blades: Kinetics, reaction mechanisms, and life cycle assessment

The sustainable management of decommissioned wind turbine blades (DWTBs) has emerged as a critical challenge for the wind energy sector. This study systematically investigated the pyrolysis behavior of DWTBs by combining experimental characterization, multi-component dynamic simulation and life cycle assessment (LCA). Kinetic analysis revealed that the primary mass-loss stage occurred within 450 °C, yielding a solid residue of 79.1–81.6 wt%. As the conversion progressed, the reaction mechanism transitioned from the F1/F3 model to the F2/F3 model. GC–MS characterization demonstrated that pyrolysis tar was dominated by phenolic derivatives, with phenyl carbamate exhibiting the highest relative abundance (24.7%). This finding confirms the profound—yet previously overlooked—participation of nitrogen-containing curing agents in the macromolecular cleavage pathways. A four-pseudo-component reaction model optimized using a genetic algorithm (GA) successfully decoupled the overlapping decomposition behavior of DWTBs, achieving excellent predictive accuracy (F dev < 2.1%). Notably, a previously unreported “reaction-order inversion” phenomenon was identified at ultra-high heating rates (≥200 °C/min), where kinetically driven collision frequencies overrode thermodynamically favored pathways, causing the strongly cross-linked network to degrade prior to the weakly cross-linked network. LCA results further revealed that, although pyrolysis is inherently energy-intensive, the recovery of glass fibers generated substantial environmental credits (−93.1 Pt), significantly offsetting the environmental burdens of the process. Moreover, transitioning to a renewable-energy-dominated electricity mix reduced the carbon footprint from 4530 to 340 kg CO 2 /t-blade. Collectively, this work provides robust kinetic parameters, mechanistic insights, and environmental performance benchmarks for the large-scale implementation of industrial DWTBs recycling technologies.