Closing the loop: Structural, environmental and regional assessments of industrial symbiosis

Regional symbiosis, based on industrial symbiosis principles, is one possible strategy for managing the environmental impact of human activities and the increasing risks associated with resource availability. An assessment is needed to ensure the benefits of implementing synergies in a region. Current research focuses on the environmental and structural analysis of symbiosis networks but lacks frameworks that consider the benefits of symbiosis at the regional scale. By combining ecological network analysis (ENA), circularity metrics and the life cycle assessment (LCA) approach, this study intends to analyze the benefits brought by expanding industrial symbiosis to a broader region. Through the analysis of different symbiosis scenarios under two energetic cases (electricity and biomethane production), the study showed that implementing regional symbiosis was a lever to improve the robustness, the circularity and the environmental impact of the system. The environmental dimension was lowly affected by the scenario changes, but they provided a wider effect on regional metrics. The change in energetic production did not bring significant differences in the results. This study also showed that the structural metrics followed a different trend than the regional and environmental metrics, revealing the complementary views that were brought by the multidimensional analysis. It advocates for a holistic assessment of systems and highlights network structural organization, which should be accounted for in regional sustainability planning.