Developing strategies for improved economic performance and reduced climate impact of landfill mining in Europe

Sammanfattning: Landfill mining refers to the re-circulation of resources from the previously deposited wastes. It is an alternative approach for managing landfills that integrates resource recovery with site remediation. Several resources that can be recovered in landfills include scrap metals for recycling, combustibles for energy recovery, and inert materials for construction applications. In addition, land can be recovered for alternative uses, or landfill void space can be liberated for the deposition of future wastes. At present, landfill mining is still an emerging concept with few project implementations. Consequently, the assessments of its economic and climate implications are case study-specific, limiting the understanding of its potential in a wider geographical scope.  This thesis aims to assess the economic performance and climate impact of landfill mining in Europe towards the development of sound strategies for implementation. Different project setups are assessed in relation to varying factors at the site level such as waste composition and landfill settings, and at the system level such as policy and market conditions and background material and energy. In doing so, a factor-based method is developed and applied to generate multiple scenarios (531, 441 scenarios per project setup) and determine the underlying important factors and their interrelations that drive the results. Such understanding is used to develop and discuss strategies for improvement by addressing relevant questions for specific stakeholders, including project investors (i.e., which landfill sites to prioritize?), landfill mining practitioners (i.e., how to set up such projects?), and policymakers (i.e., which policy instruments can effectively support such projects?).  Results show that landfill mining is preferable in terms of climate than economy. In general, about 50% of the scenarios are climate beneficial, while only about 20% of the scenarios are profitable. Possible economic and climate improvements are shown by employing internal thermal treatment of combustibles and extending fines residue utilization as construction aggregates. However, these require overarching conditions such that the choice of project setup must be in line with the selection of landfills for mining. Preferable site and system-level conditions are identified in general but it is also discussed that the plausibility of finding such conditions may be difficult at present. This steers the development of more tailored strategies on what can be done now by the landfill practitioners in terms of setting up projects under current policy and market conditions in specific regions, or what can be done by the policymakers in terms of implementing various policy instruments that can drive such changes at the system level. In this regard, the future of landfill mining research can be guided towards addressing key challenges and potential solutions for improvement elicited through a generic and learning-oriented assessment. Furthermore, this thesis highlights the role of assessment as a tool for learning and guiding the development of emerging concepts such as landfill mining.