How to select the best approach for circular economy assessment? 3D positioning framework, decision support tool and critical analysis for bio-based systems

Although the transition from linear to circular economy is being carried out by many different actors, there is still not a well-established methodology for its assessment. In this paper, a review of available approaches for evaluating circular economy (technical and biological cycles) has been conducted. In total, 2.113 information sources have been revised and 105 of them were included in the review. They have been categorised per level (macro, meso, micro and nano), cycle (technical, biological or both) and methodology used, together with the sector according to NACE codes. Using this information, a positioning framework for classifying the different appraisal options has been developed and depicted in a 3D cube where each category is represented in one of the axes (level, cycle, and methodology). Moreover, a decision support tool has been created to help triple helix stakeholders selecting the most suitable approach according to the information they are looking for, i.e. the initial question they pose regarding how to assess circular economy. Since the main gap concerning available approaches has been identified for the biological cycle at micro and nano levels, a critical analysis of existing choices has been conducted. Finally, open areas for future work towards promoting circular bioeconomy assessment are identified.