Understanding key factors driving circularity in plastic systems through material flow analysis: Findings from Portugal

This article presents a structured approach integrating Material Flow Analysis (MFA) and circularity indicators to assess key factors affecting material circularity, illustrated through a Material Flow Analysis of plastic flows in Portugal. The study follows material flows from polymer production to post-consumption treatment, measures circularity indicators across various system boundaries. A sensitivity analysis is performed to evaluate the effects of specific variables on circularity. Results highlight the limited circularity of plastics in Portugal, with a recycling rate of only 17% and a Material Circularity Indicator of 20.9%. The analysis highlights key areas for improvement: increasing production efficiency, boosting the fraction collected for recycling, and raising the fraction of product feedstock derived from recycled materials. These measures have the potential to enhance circular performance individually (up to 35%) but targeting multiple variables simultaneously (such as, fraction collected for recycling and production efficiency) produces greater benefits (71% increase). Projections suggest that, while circularity is likely to improve in recycling and material reintegration. However, significant challenges remain, particularly in the early stages of waste management. The proposed Material Flow Analysis -based framework allows for a comprehensive understanding of how different processes and material flows affect circularity outcomes. It also provides a foundation for targeted policy and industry actions. Although the study focus on plastics, the approach is widely applicable to other materials and sectors. This framework offers a practical tool for assessing and designing more circular systems throughout the economy. • Approach to assess key factors affecting material circularity. • Static Material Flow Analysis (MFA) for plastic in Portugal for six years. • Results indicate a 17% recycling rate and 20.9% material circularity indicator. • Key improvements include increasing production efficiency and waste for recycling. • Targeting multiple variables at once can lead to 71% improvements in circularity.