Analysis of carbon reduction potential from typical municipal solid waste incineration plants under MSW classification

Abstract

The disposal of municipal solid waste (MSW) is a significant source of greenhouse gas (GHG) emissions. As incineration becomes the primary method of MSW disposal in China, MSW incineration (MSWI) plants are expected to play a crucial role in mitigating GHG emissions in the waste sector. This study estimated the quarterly GHG emissions from two representative MSWI plants in Qingdao using a life-cycle assessment (LCA) approach. Additionally, the potential for GHG emissions reduction in MSWI was explored. The findings indicated that, in 2022, the GHG emission intensity for plants A and B were 56.55 and 96.73 kg CO₂-eq/t MSW, respectively. The fluctuating composition of MSW, particularly the proportions of recyclables and food waste, could significantly impact GHG emissions from MSWI. Surprisingly, a negative correlation was observed between net GHG emissions and the recycling efficiency of recyclables, suggesting that improving the sorting efficiency of recyclables may not yield substantial carbon reduction advantages for the final incineration of MSW. The utilization of waste heat for heating presented a higher potential for carbon reduction compared to incineration for power generation. Consequently, the reuse of residual steam heat, the application of carbon flue gas capture technology, and proper co-combustion with industrial solid waste or municipal sludge are viable strategies for mitigating GHG emissions from MSWI plants.

Keywords: Carbon reduction; Greenhouse gas emissions; Life-cycle assessment; MSW classification; Municipal solid waste incineration.