EcoStrategic index: Economic value creation through product portfolio diversity for waste-to-x technologies

Sustainable decision-making for waste-to-X technologies presents a challenge, encompassing numerous alternatives across the entire supply chain, from biomass selection to diverse product portfolios. Each decision affects sustainability assessments, which span environmental, economic, social, technological, and circularity aspects. Addressing a gap in aligning product portfolio management with circular economy principles, this study introduces the EcoStrategic Index, a composite metric to quantify economic values within potential product portfolios. As part of a broader framework, the EcoStrategic Index integrates seamlessly with other dimensions to support strategic decision-making. Employing the value pyramid of bio-products concept, this study establishes a benchmark classification of chemicals with expert-informed values. Empirical validation was performed through a comparative case study of gasification and pyrolysis technologies, with catalogued product portfolios of approximately 300 and 1000 entries, respectively. Results show that over 50 % of both portfolios consist of functionalized hydrocarbons, with pyrolysis yielding a greater share of fine chemicals (28 %) compared to gasification (1 %), while gasification produces a larger share of inorganic salts and fertilizers (7 %). EcoStrategic Indices indicate that pyrolysis scores equal to or higher than gasification across all five sub-indices in multiple scenarios. To demonstrate its integrability, the TechnoStraegic Index was introduced, adding technology readiness level concept to form a cross-dimensional index reflecting economic value creation and technological maturity. The results show that while pyrolysis exhibits stronger potential for economic value, gasification often outperforms in cross-dimensional evaluations due to considerable higher technological maturity. This framework offers a cost-effective tool for guiding technology selection and strategic planning toward sustainable goals.