Critical factors for economic and environmental performance of landfill mining- learnings from three case studies in Sweden

In the last couple of years several studies have attempted to assess the environmental and economic performance of landfill mining projects. However, most of these assessments are based on single non-full scale projects and... [ view full abstract ]

In the last couple of years several studies have attempted to assess the environmental and economic performance of landfill mining projects. However, most of these assessments are based on single non-full scale projects and there have been few studies trying to synthesize results from several projects. These means that the results are not conclusive and that there is still a lot to learn about how different settings and system conditions influence performance. Which critical factors govern the performance and how can different technology set-ups influence the performance?

This study assess three vastly different landfill mining set-ups, a shredder waste landfill, a landfill for incineration fly ash and a household waste based old bioreactor. They have different material compositions and also different drivers behind the reason for excavation. They are also different in the respect to data availability since the shredder landfill and the bioreactor both has large scale test excavations whereas the fly ash landfill is a hypothetical case. The aim of this study is two-fold, first to through three very different lfm cases learn more about critical factors influencing economic performance and impact on climate change. Secondly to understand how different technological set-ups influence which critical factors that can be identified.

First the cases are assessed with a conventional technology set-up and then the major barriers which can be identified with these set-ups (i.e. inefficient separation, low quality fractions, impurities affecting marketability) are used to develop more advanced technology set-ups. Secondly economic performance and impact on climate change for the different cases and set-ups are evaluated. The economic performance is calculated based on the perspective of the landfill mining organisation and the climate change calculations are based on a life cycle approach.

Preliminary results suggests that for the economic performance the alternative costs often connected with the driving force behind the excavations are very important as well as the ability to get a combustible fraction with a quality which the incineration actors deem sufficient. Depending on the landfills the impact on climate change seem to be linked to how remaining methane potential in the deposited waste is modelled and also how the incineration processes are modelled.