Comprehensive characterization of heavy fraction of tire pyrolysis oil and its blends with heavy oil: From liquid evaporation to coke combustion

Poonawala, Taha (Universidad de Zaragoza) ; Muelas, Álvaro (Universidad de Zaragoza) ; Ballester, Javier (Universidad de Zaragoza)

Resumen: The combustion of the liquid heavy fraction obtained after distilling the raw tire pyrolysis oil poses some challenges analogous to those of heavy fuel oil (HFO). Namely, its evaporation process and the formation and subsequent slow oxidation of solid residues are the most relevant issues that need attention to achieve a clean conversion of this alternative fuel. However, despite its relevance, the combustion characteristics of this heavy fraction of tire pyrolysis oil (TPO) remains mostly unexplored. This work aims to fill this gap by characterizing in detail the liquid and solid burning stages, including the envelope flame, of single droplets of TPO, HFO and their blends. The morphology of the solid particles is also analyzed using SEM-EDX. TPO droplets are found to follow evolution stages similar to HFO, but with liquid consumption times ∼1.5 shorter and cenospheres significantly smaller (36–43 % the size of HFO cokes). TPO cenospheres are hollow and have thin (∼10 µm), sponge-like walls, showing large deposits of soot even on the inner surfaces. This results in a rapid oxidation of TPO cokes through a mixed burning regime, ∼4 times faster than HFO cenospheres (which rather burnt in a constant-diameter regime). All HFO-TPO blends exhibited perfect miscibility without requiring co-solvents, with TPO addition significantly reducing HFO viscosity. Interestingly, different TPO concentrations had a similar effect on the liquid droplet lifetime, with reductions ∼12%. Likewise, the initial cenosphere size was reduced to a similar degree (∼33 %) for different TPO addition levels, their consumption being also faster due to the increased porosity of the cenosphere walls. These favorable effects thus point to the potential of TPO/HFO blending as a promising method to utilize both fuels in a synergistical manner, as a means to valorize TPO and, at the same time, improve efficiency and reduce particulate emissions in HFO combustion.

Idioma: Inglés

DOI: 10.1016/j.proci.2025.105880

Año: 2025

Publicado en: PROCEEDINGS OF THE COMBUSTION INSTITUTE 41 (2025), 105880 [7 pp.]
ISSN: 1540-7489

Financiación: info:eu-repo/grantAgreement/ES/AEI/PID2022-140620OB-I00
Financiación: info:eu-repo/grantAgreement/ES/MICINN PRE2020-094620

Tipo y forma: Article (Published version)

Área (Departamento): Área Mecánica de Fluidos (Dpto. Ciencia Tecnol.Mater.Fl.)