Experimental study on co-combustion and co-pyrolysis characteristics of end-of-life wind turbine blade (WTB) and coal

A concentrated wave of wind turbine blades (WTB) decommissioning is anticipated globally over the next few years. However, there remains a lack of systematic understanding regarding the thermochemical conversion and co-processing of end-of-life WTB composite waste. Although a series of laboratory-scale research has been conducted, the thermochemical behavior and interaction mechanisms of WTB-derived composite materials during co-processing with coal remain insufficiently understood. Most existing research focuses on a single composite material or model compound, while little attention has been paid to the thermal conversion mechanism of actual end-of-life WTB-derived composite materials and their coupled conversion with coal. In the current research, the thermal weight loss behavior and product evolution patterns of end-of-life WTB-derived materials, coal, and their blended samples during pyrolysis and combustion were investigated. A series of characterization techniques was employed, and a comprehensive comparative analysis of the combustion and pyrolysis process was conducted. The product distribution patterns and kinetic characteristics of the WTB-coal blend samples during thermochemical conversion were revealed. The findings show that there is significant synergistic cracking and oxidation between coal and WTB. The reaction behaviour of the WTB samples is jointly governed by epoxy resin matrix cracking, aromatic structure reconstruction, and high-temperature oxidation of residual char. After coal addition, the reaction mechanism shifts from a complex, multi-step chain-scission process to one dominated by volatile release and surface reactions. In addition, quantitative measurements from settling-furnace combustion experiments showed that the addition of 10 wt% WTB-1 reduced NO x concentrations by approximately 7.2∼17.2% at 1000–1300 °C, with an average reduction of approximately 11.6%, while NO concentrations decreased by approximately 7.1∼17.3%.These findings provide experimental evidence and mechanistic insights into the coupled thermochemical conversion of end-of-life WTB-derived materials and coal, and provide a scientific basis for further evaluation of WTB/coal co-processing.