SCREEN-LCA: Ex-ante prioritization of bio-based pathways for chemicals and plastics under a climate-mitigation objective

Life cycle assessment (LCA) is a key tool for guiding circular bioeconomy strategies, including the substitution of fossil carbon with bioresources. However, its data- and time-intensive nature can hinder its use when there are numerous candidate pathways, particularly in the chemical sector. Here, we developed SCREEN-LCA, a stepwise ex-ante framework designed to prioritize case studies before conducting full LCA. The framework combines: (i) sector-level impact estimation; (ii) identification of hotspot products within targeted sectors; (iii) mapping of corresponding alternative bio-based pathways; and (iv) pathway prioritization based on multiple criteria. We applied SCREEN-LCA in a France-oriented demonstration to prioritize residual-biomass-based pathways for subsequent LCA. The greenhouse gas footprint of incumbent petrochemicals and plastics, feedstock compatibility, and technological maturity were used as screening criteria. An extensive graph database covering 50 hotspot products and their alternative bio-based routes was assembled. Ethylene, propylene, methanol, and PET emerged as priorities with promising bio-based alternatives.