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This paper summarizes the 76th LCA Discussion Forum end its main findings. Main issues when addressing emerging technologies identified were: the lack of primary data, the need for (shared) future background scenarios and (guidlines for) a common methodology. The following recommendations have been derived by the organizers: 1) Specific foreground inventories are always tailor-made, but consistency can be improved through lists of mandatory considerations. 2) Continue sharing (future) technology data and proxy processes, that can be readily replicated to new studies and assist in developing inventories. 3) Streamline and unify the process of including scenarios for background systems. New approaches may provide first important solutions to efficiently include consistent future scenarios in prospective LCA.

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Aluminum is an energy-intensive material that is typically used as an alloy. The environmental impacts caused by its production can potentially be spread out over multiple uses through repeated recycling loops. However, inter-alloy contamination can limit the circularity of aluminum, which highlights the importance of analyzing prospective stock dynamics of aluminum at an alloy and alloying element level to inform a more sustainable management of this resource. A dynamic material flow analysis (MFA) of aluminum alloys was developed in line with the shared socioeconomic pathways (SSP) framework to generate consistent scenarios of the evolution of aluminum stocks and flows from 2015 to 2100 covering 11 economic sectors in 5 world regions. A sectorspecific and bottom-up modeling approach was developed. Results show no saturation of global stock per capita before 2100, reaching a range between 200 and 400 kg per capita according to different socioeconomic scenarios. For the business-as-usual scenario, the global annual inflow rises to 100 Mt in 2050 and peaks at 130 Mt in 2090, showing a saturation in total stock. Electricity-sector demand has the highest relative growth over the century, while building and construction demand saturates and decreases from 2090. No major mismatch between inflows and outflows of aluminum alloy is observed. This means that with appropriate dismantling and sorting, changes in alloy demand would not limit the implementation of a closed-loop aluminum industry. This study demonstrates the advantages of combining detailed MFAs and SSPs, both for greater consistency in circular economy modeling and for furthering scenario development efforts. This article met the requirements for a gold-gold JIE data openness badge described at http://jie.click/badges

Aluminum recycling follows a downcycling dynamic where wrought alloys are transformed into cast alloys, accumulating tramp elements at every cycle. With the saturation of stocks of aluminum and the reduction of the demand for cast alloy due to electrification of transport, improvement in the recycling system must be made to avoid a surplus of unused recycled aluminum, reduce the overall environmental impacts of the industry, and move toward a circular economy. We aim to evaluate the potential environmental benefits of improving sorting efforts by combining operations research, prospective material flow analysis, and life cycle assessment. An optimization defines the optimal sorting to minimize climate change impacts according to different sorting efforts, dismantling conditions, and collection rates. Results show how the improvement of sorting can reduce by around 30% the greenhouse gas emissions of the industry, notably by reducing unused scrap generation and increasing the recycled content of the flows that supply the demand of aluminum. The best performance is achievable with four different sorting pathways. Further improvements occur with a better dismantling and an increase of collection rates, but it requires more sorting pathways. Results point to different closed‐loop recycling initiatives that should be promoted on priority in specific sectors, like the building and construction sector and the aluminum cans industry. To implement a better material circularity, the mobilization of different stakeholders is needed. From a wider perspective, the article shows how operations research can be used to project a circular future in a specific industry. This article met the requirements for a Gold–Gold JIE data openness badge described at http://jie.click/badges.