Environmental impact assessment of carbon-negative bio-based plastics advancing sustainable feedstock utilization

This study evaluates the potential of second and third-generation feedstocks for bio-based plastic production, aiming to replace up to 82 % of global plastic demand while achieving carbon-negative outcomes. Life Cycle Inventory (LCI) analysis was conducted to assess greenhouse gas emissions, energy consumption, land use, and resource efficiency. Results indicate that allocation methods significantly impact Global Warming Potential (GWP), with economic and mass allocation increasing GWP by 32 % to 173 % for second-generation crops, while mass allocation benefits first-generation crops by reducing emissions. Additional environmental factors, including water consumption and fossil fuel dependency, were examined to provide a comprehensive sustainability assessment. Strategies for minimizing emissions and optimizing production include decarbonizing energy inputs, reducing ammonia-based fertilizer use, integrating renewable hydrogen, adopting bio-based alternatives, enhancing enzyme production, and improving biomass conversion processes. Findings highlight the importance of balancing multiple environmental factors to ensure bio-based plastics contribute effectively to sustainability goals.