Transitioning towards standardised circular economy assessments; application to high-value production from OFMSW biogas

Abstract

Publication of the European Green Deal, and subsequent Circular Economy Action Plan, establishes improving resource circularity as a key pillar of Europe’s sustainable development plan. However, a higher degree of circularity does not automatically result in a more sustainable economy, meaning the newly published ISO59020 for circularity performance measurement and assessment demands the completion of complementary sustainability analysis to support decision making. Therefore, this work aims to complete a holistic circularity assessment in line with ISO59020, by assessing both conventional and novel production processes of a high value cosmetic ingredient, that has potential to be generated from waste-derived biogas. This was achieved by applying standardised methods for circularity and environmental (life cycle assessment), economic (technoeconomic assessment), and social (social life cycle assessment) sustainability assessment. The novel process performed poorly in terms of water and emissions circularity, meaning investments are required for water upgrading and recycling technologies, and that CO₂ emissions should be recirculated to the biogas generation plant. However, even though the process performed well across sustainability dimensions, it was clear the process was vulnerable to performance deterioration if circularity and sustainability assessment results were considered independently. Specifically, the impacts of local water usage and grid electricity did not impact sustainability performance, whilst circularity indicators showed reliance on large freshwater demands and highly renewable grid electricity to maintain performance. Therefore, the need for harmonised assessments of circularity and sustainability is clear, and further work is needed to develop robust tools for combining impact indicators into a single, easily utilised metric.