Comparing a material circularity indicator to life cycle assessment: The case of a three-layer plastic packaging

Abstract

There is a serious need to assess the evolution of transitions from a linear to a Circular Economy (CE) using tools, metrics, and measurement indicators that not only are able to take into account the circularity, but also the other sustainability performances of products. Currently, most measurement tools do not lead to valuable decisions, as they do not capture the performance of the CE in its entirety, resulting in poorer performance on certain aspects, such as the environment. In addition, the lack of industry-specific indicators may hinder the adaptation of CE due to the different structures and functions of products. Consequently, this paper proposes a circularity indicator adapted from the Material Circularity Indicator (MCI) for the plastic industry, specifically Multi-layer Plastic Packaging (MPP). The adapted indicator is expanded based on the quality of recycled polymers by defining a new utility factor (X) as the polymers' intensity of re-use. It also highlights that it is necessary to combine a circularity indicator with Life Cycle Assessment (LCA) for viable end-of-life (EOL) management. To illustrate the use of the proposed indicator and the trade-offs between circularity and environmental impacts, a case study on three-layer plastic packaging is applied to two end-of-life scenarios (Incineration, and closed-loop mechanical recycling). The results show that an increase in material circularity generally decreases the environmental impacts. However, recycling was found to have a higher impact than incineration on some impact categories such as land use and freshwater eutrophication.