Life cycle assessment of structured polymer–carbon composites from date palm fronds: Environmental hotspots and energy recovery potential

Biomass–plastic integration enables the conversion of powdered activated carbon (AC) into structured composites with improved handling and recovery. This study presents a process-based life cycle assessment (LCA) of polyethylene (PE)-integrated AC composites derived from date palm (Phoenix dactylifera) fronds (PF). The analysis identifies the environmental burdens, hotspots, and sensitivities associated with activation route, pyrolysis processing, and electricity source. The analysis was further extended to evaluate pyrolysis gas emissions and the energy recovery potential of by-products. Under the baseline natural gas electricity scenario, climate change (CC) impacts ranged from 4.25 to 5.43 kg CO₂ eq., while net energy demand (EN) ranged from 115 to 145 MJ depending on the activation route. Contribution analysis identified thermal processing as the dominant contributor to CC impacts, whereas sensitivity analysis revealed pyrolysis as the most influential process parameter. Alternative electricity scenarios altered environmental performance. Additional assessments indicated that pyrolysis gas and oil provide a combined energy recovery potential of 21.5 MJ kg⁻¹ AC, while estimated direct pyrolysis emissions included 0.663 kg biogenic CO₂ kg⁻¹ AC and methane emissions equivalent to 2.40 kg CO₂-eq kg⁻¹ AC. Overall, pyrolysis emerged as the dominant environmental hotspot, highlighting the importance of thermal-process optimization, energy recovery, and low-carbon energy sources for improving the sustainability of biomass-derived AC composites.