Multi-scale assessment of global warming mitigation potential of anaerobic digestion for food waste management in the United States: A comparison of Life Cycle Assessment approaches

This study provides a holistic Life Cycle Assessment (LCA) for evaluating the decarbonization potential of using Anaerobic Digestion (AD) in food waste treatment. The LCA is based on the development of a new flexible tool that allows the integration of the LCA at the process level with geospatial data and therefore includes a wide range of factors such as multiple feedstocks, technologies for end -use applications, and facility locations. This tool estimates a potential for reducing 21.8 MMtons CO2eq/y (345 gCO2eq/kgwaste) and generating 161 TBTU/y of renewable natural gas for the whole United States by managing food waste based on waste-hierarchy. This study also identifies those states with a more efficient AD implementation potential regarding CO2eq avoidance. It highlights the importance of including region-specific conditions since feedstock diversion depends on the state and is the main contributor to the decarbonization potential, up to 60 % of the avoided emissions.