Thermal treatment characteristics and kinetic analysis of decommissioned wind turbine blades
To examine the thermal treatment characteristics of decommissioned wind turbine blades,thermogravimetric analyses were conducted on glass fiber/epoxy resin wind turbine blades under various heating rates(5、10、20、40 ℃·min-1)and in two distinct atmospheres(nitrogen and air).Each reaction process was meticulously analyzed using kinetic methods.The thermogravimetric results revealed two distinct weight loss stages for the blades in nitrogen atmosphere,stabilizing in mass post 500 ℃.In an air atmosphere,three weight loss stages were observed,with mass stabilization occurring post 600 ℃.This suggests that the presence of oxygen significantly influences the thermal decomposition of glass fiber/epoxy resin.TG/DTG curve comparisons at different heating rates indicated a high-temperature shift of the TG curve with increasing heating rate,a gradual decrease in the peak weight loss of the DTG curve,and a slight reduction in overall mass loss during the reaction.The kinetic processes were scrutinized using the Kissinger-Akahira-Sunose(KAS)and Flynn-Wall-Ozawa(FWO)methods.The activation energies determined for pyrolysis and oxidation reactions using these kinetic models ranged from 135.14~207.24 kJ·mol-1,137.64~207.58 kJ·mol-1,117.95~172.19 kJ·mol-1,119.31~173.22 kJ·mol-1,with mean values of 179.30 kJ·mol-1,180.44 kJ·mol-1,141.18 kJ·mol-1,143.15 kJ·mol-1,respectively.The KAS and FWO methods applied to analyze identical reactions,produced congruent data sets.The mechanistic model of the reaction process was explored using the Coats-Redfern(CR)method.The results indicated that the pyrolysis process followed an A1/2 mechanism,while the oxidation process conformed to the F3 mechanism.This study provides significant theoretical and methodological references for the effective disposal and resource recycling of large-scale periodic decommissioned wind turbine blades.