Low-Carbon Thermochemical Upcycling of Plastic Waste with Steel Slag at Elevated Temperatures

作者：Ke Tang, Junjun Wu, Wei Ren, Xun Zhu, Qiang Liao · 发表于：Industrial & Engineering Chemistry Research · 年份：2025 · DOI：10.1021/acs.iecr.5c03356 · 被引用次数：1 · 研究领域：Thermochemical Biomass Conversion Processes、Recycling and utilization of industrial and municipal waste in materials production、Thermal and Kinetic Analysis

Plastic waste (PW) poses a severe global environmental threat, with thermochemical upcycling offering a promising solution. However, conventional pyrolysis faces challenges in terms of energy intensity and catalyst dependency. This study proposes a synergistic approach using high-temperature steel slag (SS) as both a heat carrier and a catalyst for low-carbon PW upcycling. We investigate the co-pyrolysis of four major plastics─HDPE, PP, PS, and PET─with SS and its primary oxides (CaO, MgO, SiO 2, Al 2 O 3, Fe 2 O 3, TiO 2 ) via TG-FTIR-GC/MS. Results demonstrate that SS significantly alters product selectivity: PS pyrolysis yields >90% aromatic hydrocarbons (mainly styrene), PET decomposition shifts from acids to acetaldehyde/CO 2, while HDPE/PP primarily generate alkenes/alkanes. Kinetic analysis (Freeman-Carroll method) confirms reduced activation energies (e.g., 208 kJ·mol –1 for PET/SS vs 318 kJ·mol –1 for pure PET). Crucially, waste heat from SS (1173–1673 K) exceeds pyrolysis energy demands by 41–73 MWh/t-SS, enabling net energy recovery. This work validates SS as a sustainable dual-functional material for scalable PW valorization.