Fast co-pyrolysis characteristics of polyethylene terephthalate and epoxy resin from waste wind turbine blades

The present study systematically investigated the fast co-pyrolysis characteristics of epoxy resin and polyethylene terephthalate (PET) derived from waste wind turbine blades, with the aim of uncovering the possible synergistic effect in co-pyrolysis. The co-pyrolysis of epoxy resin and PET was beneficial to the formation of pyrolytic char, while the generation of small molecule gaseous products was restrained to a certain degree. The kinetic results revealed that the presence of epoxy resin dramatically reduced the energy barrier for PET decomposition into terephthalic acid (TPA) and vinyl benzoate via a cyclic transition state, finally resulting in an obvious reduction in the activation energy of the pyrolysis reaction. Remarkably, the activation energy for co-pyrolysis sharply decreased to around 150 kJ/mol at a low conversion rate. The co-pyrolysis presented a significant impact on the further transformation of primary pyrolysis products via decarboxylation, deoxygenation, decarbonylation, isomerization, and so on, thus contributing to the selective production of specified chemicals. Furthermore, the plausible reaction pathways and synergistic mechanisms between co-pyrolysis of epoxy resin and PET were discussed thoroughly.