Comparative life cycle assessment of organic industrial solid waste co-disposal in a MSW incineration plant

Abstract

Co-disposal experiments involving industrial solid waste (ISW) are conducted at a municipal solid waste (MSW) incineration plant in this study, investing the environmental impact of co-disposal with different ISW addition proportions using life cycle assessment (LCA). Results show that increasing ISW proportions improves economic indicators, reducing the payback period from 7.92 years (0% ISW) to 6.58 years (40% ISW). Environmental impact indicators initially decrease and then increase. The indicator with the greatest environmental impact is Eutrophication Potential (EP), the only major indicator with positive values in all scenarios when considering power output. Its normalization value reaches a minimum at 30% ISW blending, at 7.85×10-12. Contribution analysis reveals that the direct emissions of N-containing gases are the primary cause, while the addition of urea, ammonia water, and quicklime in flue gas treatment, as well as the ash-slag landfill, also have significant effects. Technical optimization of stepwise co-disposal, denitrification system and ash-slag reduction will be the focus. Compared to the existing conventional situation, the co-disposal system exhibits considerable improvements in environmental benefits and carbon reduction potential. Notably, there is a significant reduction in non-CO2 greenhouse gas emissions. This study offers theoretical insights for multi-source waste disposal in MSW incineration plants.