Innovation in rare earths recycling: a quantitative and qualitative analysis of patent data

The rare earth elements (REE) are currently essential enablers of the digital and decarbonization transitions. Nonetheless, their supply chain is highly concentrated and their extraction has high environmental impacts. Circular economy solutions could provide a twofold benefit, reducing the supply risk for import-dependent countries and mitigating REE mining impacts. This article focuses on REE recycling, providing a comprehensive, global overview of innovation dynamics in that sector by means of patent data. We propose a two-steps patent search methodology for the identification of REE recycling patents, based on OECD ENV-TECH classification for green technologies and keywords occurrence. Hence, we develop a series of quantitative and qualitative metrics to explore innovation dynamics at the country, applicant and technology type level. China clearly emerges as the most attractive market for REE recycling patents and Chinese universities as the most active applicants globally. Conversely, patent applications in all other countries registered stagnating trends over the last decade. In Europe, in particular, a lower number of patents are both filed and developed with respect to the US and Japan. However, patent quality indicators present a quite different picture, with US and Japanese applicants that seem to be at the technological forefront, receiving more citations and being more oriented to protect their inventions internationally. Therefore, our analysis underlines the importance of considering both quantitative and qualitative patent metrics when exploring innovation trends in REE recycling. We discuss the determinants of these observed phenomena and provide policy implications, particularly for countries dependent on REE imports.