No abstract

Industrial symbiosis networks are generally assumed to provide economic and environmental benefits for all firms involved, though few quantifications have been produced in the literature, and the methods for these quantifications have varied. This paper provides an approach to quantify environmental performance of industrial symbiosis using guidance from the literature of life cycle assessment. Additionally, an approach to distribute credits due to exchanges for firms in the industrial symbiosis network is outlined. From the approach, influential methodological considerations used for the quantifications are discussed, including e.g. the production of reference systems, allocation methods, system boundaries and functional unit. The implications of such an approach may be beneficial for the industrial symbiosis community and provide information crucial for taxes, subsidies, business relations, expansion possibilities for the network, marketing and other issues related to the environmental performance of firms in the industrial symbiosis network.

Studies concerning landfill mining have historically focused on reclamation of land space and landfill remediation. A limited number of studies, however, have evaluated landfill mining combined with resource recovery, most of them being pilot studies or projects with little emphasis on resource extraction. This implies that many uncertainties remain related to landfill mining. With a growing interest in environmental concerns around the globe, the environmental evaluation of large-scale projects has become an increasingly important issue. A common way of conducting such an evaluation is to use Life Cycle Assessment (LCA). However, LCA by itself might not take into account all the inherent uncertainties in landfill mining. This article describes an approach for environmental evaluation of landfill mining that combines the principles of Life Cycle Assessment and Monte Carlo Simulation. In order to demonstrate its usability for planning and evaluation purposes, the approach is also applied to a hypothetical landfill mining case by presenting examples of the types of results it can produce. Results from this approach are presented as cumulative probability distributions, rather than a single result figure. By presenting results in this way, the landfill mining practitioner will get a more complete view of the processes involved and will have a better decision base.

Large technical systems serving the everyday needs of people, such as water supply systems, power grids or communication networks, are rich in accumulated metals. Over time, parts of these systems have been taken out of use without the system infrastructure being removed from its original location. Such metal stocks in hibernation thus constitute potential resource reservoirs accessible for recovery. In this paper, obsolete stocks of copper situated in the local power grids of two Swedish cities are quantified. Emphasis is also on economic conditions for extracting such -hibernating‖ cables. The results show that on a per customer basis, the two power grids contain similar amounts of copper, i.e. 0.04-0.05 tonnes per subscriber. However, the share of the copper stock that is in hibernation differs between the grids. In the larger grid of Gothenburg, almost 20% of the copper accumulated in the grid is no longer in use, while the obsolete share does not exceed 5% in the city of Linköping. For managers of local power grids, recovery of hibernating cables could be beneficial if integrated with other maintenance work on the grid. At the present price of copper, however, separate recovery of obsolete cables is not economically justified.2

Landfill mining has been proposed as an innovative strategy to mitigate environmental risks associated with landfills, to recover secondary raw materials and energy from the deposited waste, and to enable high-valued land uses at the site. The present study quantitatively assesses the importance of specific factors and conditions for the net contribution of landfill mining to global warming using a novel, set-based modeling approach and provides policy recommendations for facilitating the development of projects contributing to global warming mitigation. Building on life-cycle assessment, scenario modeling and sensitivity analysis methods are used to identify critical factors for the climate impact of landfill mining. The net contributions to global warming of the scenarios range from -1550 (saving) to 640 (burden) kg CO2e per Mg of excavated waste. Nearly 90% of the results' total variation can be explained by changes in four factors, namely the landfill gas management in the reference case (i.e., alternative to mining the landfill), the background energy system, the composition of the excavated waste, and the applied waste-to-energy technology. Based on the analyses, circumstances under which landfill mining should be prioritized or not are identified and sensitive parameters for the climate impact assessment of landfill mining are highlighted.