On the Potential of Waste Tire Pyrolysis in Carbon Mitigation: A Review

This review aims to evaluate the carbon mitigation potential of waste tire (WT) pyrolysis through a life cycle assessment (LCA) perspective, with a focus on clarifying methodological differences across studies. The scope of the review covers the three main pyrolysis products—tire pyrolysis oil (TPO), recovered carbon black (rCB), and tire pyrolysis gas (TPG)—and their roles in two interconnected mitigation pathways: (i) material substitution, where TPO can displace fossil diesel (≈2.7–3.2 kg CO2e/kg) and rCB can replace virgin carbon black (≈1.8–2.2 kg CO2e/kg), and (ii) energy self-sufficiency, where TPG (≈30–40 MJ/m3) offsets external fuels. Unlike earlier reviews that emphasized technical feasibility, this study synthesizes comparative LCA evidence to explain why reported mitigation factors vary widely, highlighting the influence of system boundaries, substitution ratios, and product quality. Harmonizing these conventions provides a consistent basis for cross-study comparison and positions WT pyrolysis as a strategic contributor to circular economy and decarbonization agendas.