Characteristics, kinetics and product distribution on pyrolysis process for waste wind turbine blades

The surge in the number of waste wind turbine blades (WWTB) and improper disposal have resulted in the waste of land resources and potential environmental risks. The pyrolysis characteristics and product distribution of WWTB were discussed by thermogravimetry (TG), pyrolysis with gas chromatography and mass spectrometric (Py-GC/MS), and fixed bed reactor. The kinetic results showed that the average activation energy of WWTB is 125.24 kJ/mol (Flynn Wall Ozawa), 120.45 kJ/mol (Kissinger Akahira Sunose), and 124.66 kJ/mol (Friedman), which was much lower than that of sludge, pine, coal, etc. It indicated that the pyrolysis process of WWTB was more likely to occur with less energy consumption. Furthermore, Py-GC/MS results demonstrated that the carbon chain distribution of primary pyrolysis products was mostly C9–C16 (48.97–72.73 %), including mainly phenolic compounds, alcohols, ketones and carboxylic acids. The higher pyrolysis temperature was beneficial to promote the decarboxylation reaction, decarbonylation reaction and cyclization reaction in the pyrolysis reaction. Subsequently, the results of Py-GC/MS and fixed-bed reactor proved that low-temperature fast pyrolysis can contribute to the directional recovery of phenols such as bisphenol A. High temperature and long residence time would increase the production of aromatics and furans. This study clarified the applicability of pyrolysis for WWTB and provided a reference for the selection of pyrolysis process parameters and the prevention of secondary pollution of pyrolysis.