This study investigates the catalytic pyrolysis of tire recycling residues — solid waste generated during mechanical tire recycling — as a route for producing fuel-grade pyrolysis oil meeting EU regulatory requirements. Pyrolysis was conducted in a pilot-scale fixed-bed reactor at temperatures between 450 and 600 °C under a nitrogen atmosphere, using Ca(OH) 2 and MgO catalysts in direct and mixed configurations, applied either by surface deposition or by homogenization with the feedstock. The performance of each configuration was evaluated in terms of oil yield and sulfur content in the pyrolysis oil, with the 1.00 wt% sulfur threshold defined by EU Directive 2016/802 as a key benchmark. Ca(OH) 2 effectively reduced sulfur content to 0.82 wt%, while the mixed Ca(OH) 2 configuration achieved a more balanced outcome with an oil yield of 33.38 wt% and sulfur content of 0.91 wt%. MgO achieved the highest oil yield (34.5 wt%) while remaining below the sulfur threshold (0.93 wt%). In contrast, the mixed MgO configuration did not meet the regulatory limit, reaching a sulfur content of 1.01 wt%. The environmental performance of each configuration was assessed through an LCA using the Environmental Footprint (EF) 3.1 method, with a functional unit of 1 MJ of compliant pyrolytic oil. Fossil CO 2 dominated emissions across all configurations. The results confirm that catalyst selection and application mode decisively govern both product quality and carbon footprint. The pilot-scale setup used in this study provides a foundation for scale-up assessment, highlighting the potential of catalytic tire pyrolysis for industrial implementation within the circular economy. • Semi-pilot catalytic pyrolysis of tire waste enhances pyrolytic oil quality. • Ca(OH)2 reduces sulfur below 1 %, meeting EU fuel quality standards. • MgO raises oil yield (34.5 %) but complicates sulfur removal. • LCA shows Ca(OH)2 catalyst has lower carbon footprint than MgO.
Janáková et al. (Thu,) studied this question.