Life cycle-based, energy-related analysis for waste management strategies: a case study of two impact indicators in...

Municipal solid waste (MSW) is regarded to be an important source of greenhouse gas emissions, which could result in a significant impact on climate change. This study conducted analyses of both cumulative energy demand (CED) and carbon footprint (CF) indicators per reference flow (RF) and identified the relationship between both the indicators, and additionally, it made some recommendations for MSW management strategies in Pyongyang, DPR Korea, based on life cycle thinking. This present study suggested using a hybrid CED indicator and the energy-related CF indicator for the analysis of the existing MSW management system, while applying system expansion for crediting the recycled materials, the energy recovery, and the compost/fertilizer. The result showed that the CED indicator in the MSW management system accounted for - 9,569.8 MJ/RF of primary energy savings in total, corresponding to the avoided emissions of - 1,522.89 kg CO₂eq/RF. The recycling and composting of waste presented energy savings due to the recycled materials and the avoided production of mineral fertilizers replaced with the compost, respectively. In addition, the incineration had some potential for energy recovery from waste, and it could result in crediting energy further, while the landfill should be improved in a more sustainable way of making use of the landfill gas and/or replacing the landfill with incineration with energy recovery. The results also indicated that the CED indicator was closely related to the CF indicator, valued as global warming potential, throughout the MSW management options/processes, and both the indicators could serve as an appropriate proxy of the environmental impacts on a life cycle phase.