Assessing environmental impacts in Industrial Symbiosis networks: A Life Cycle Assessment literature review

In recent decades, more manufacturing companies have been collaborating across industries to share resources such as by-products, waste, and energy, primarily to gain competitive advantage. This strategic approach is known as industrial symbiosis (IS) and represents a tangible application of the circular economy in an industrial context. As a result, there has been a growing interest in assessing the environmental impacts generated by IS networks. Life Cycle Assessment (LCA) is widely recognized as an effective tool for quantifying such impacts. However, the application of LCA to IS networks poses significant challenges due to the complex nature of these systems, which often exhibit multifunctional processes. Therefore, the objective of this study is to conduct a comprehensive literature review of LCA studies in IS networks, with the aim of understanding and critically evaluating how LCA methodologies have been applied to assess these systems. The literature review includes only those papers that aim to provide general guidelines for the application of LCA methodology to IS systems (those that focus specifically on one industry are excluded). The papers deemed eligible for analysis were analyzed using the four LCA phases as a reference. Among the main findings are discrepancies in the first LCA phase, i.e. the Goal and Scope, as different approaches to defining the functional unit(s) and allocation methods emerged. The results of this analysis will provide recommendations for future LCA studies applied to IS networks.