Carbon footprint analysis and environmental impact assessment of industrial waste oil regeneration process

This study focuses on an NMP-enhanced vacuum distillation process (N-Methyl-2-pyrrolidone solvent refining) for industrial waste oil regeneration. Using a systematic life cycle assessment (LCA) framework from environmental sustainability and climate mitigation perspectives, this research conducts a comprehensive qualitative-quantitative evaluation of process carbon footprints and assesses environmental burdens across distinct production stages. The results indicate that the total carbon footprint generated from regenerating 1000 kg of industrial waste oil is 712.49 kg CO 2 eq, with the NMP refining stage contributing the most at 363.89 kg CO 2 eq (51 %), followed by the transportation and collection stage at 250 kg CO 2 eq (35 %). Consumption of electricity, natural gas, and steam in the overall production process accounts for 62 % of the total carbon emissions. In terms of environmental impacts, the most significant factor is fossil fuel consumption at 28.63 Pt, followed by respiratory (inorganic) effects at 19.24 Pt, and climate change at 5.53 Pt. The analysis reveals that direct energy consumption accounts for 62.0 % of total carbon emissions, representing the primary decarbonization opportunity. Consequently, improving energy utilization efficiency and integrating renewable energy sources emerge as paramount strategies for industrial waste oil regeneration enterprises to achieve carbon reduction goals.