Energy valorization of tyres waste

Energy valorization of worn out tyres was studied. Two hypothesis were taken into account: co-combustion and pyrolysis. Firstly, a tyre sample was characterized by elemental analysis for the determination of the content of C, H and other elements, and the evaluation of its heat of combustion. Regarding its lower heating value, the tyre sample presents interesting features. Pyrolysis of the same tyre sample was studied by TG-MS/TG-GC-MS analyses and lab-scale reactor tests. The thermal decomposition of the waste tyre produced a gaseous phase (20%wt of the tyre mass), a tyre pyrolysis oil (TPO, 40% wt) and the solid char (40% wt). Both tar and char were characterized by elemental analysis and heat of combustion determination. TPO presented HHV and LHV of 49.5 and 46.7 MJ/kg, while the HHV and LHV for solid char char were 34.7 and 33.7 MJ/kg, respectively. A case of process application was studied, taking into account the features of waste tyres combustion plants and pyrolysis processes.