Experimental and kinetic investigation of biomass pyrolysis toward sustainable carbon carriers for the steel industry

<ns3:p> The European steel industry, responsible for nearly 7-8% of global CO <ns3:sub>2</ns3:sub> emissions, faces an urgent need to decarbonize in line with the European Green Deal targets. Within this framework, the EU-funded BioCoDe project (Biomass for Cokemaking Decarbonization) explores the potential of biomass-derived carbon carriers to partially substitute fossil coal in the cokemaking process, enabling up to a 10% reduction in fossil carbon use. This study presents the experimental and kinetic characterization of five representative biomass feedstocks, olive branches, olive trunks, pine, pallet wood, and wooden crates, tested in laboratory-scale pyrolysis experiments carried out at RINA-CSM (Centro Sviluppo Materiali). Thermogravimetric analyses (TGA) were conducted under inert conditions to investigate the thermal degradation behavior of the feedstocks. Kinetic parameters were derived using the Coats–Redfern integral method, evaluating different reaction orders to determine activation energies and pre-exponential factors. The results reveal significant differences in thermal stability and decomposition kinetics linked to the lignocellulosic composition of the biomass, particularly the hemicellulose-to-lignin ratio. These findings provide a robust kinetic framework for optimizing pyrolysis conditions and selecting suitable precursors for high-quality biochar production. Overall, this study supports the technical feasibility of integrating biomass-based carbon carriers into the steel sector as a complementary and immediately deployable solution for reducing CO <ns3:sub>2</ns3:sub> emissions. </ns3:p>