Research on carbon emission reduction potential of sorting, treatment and disposal of low-value recyclables from municipal solid waste

The sorting, treatment and disposal of municipal solid waste (MSW) is a significant source of urban greenhouse gas (GHG) emissions. The sorting of low-value recyclables (LVRs) in MSW helps reduce waste and maximize resource utilization, playing a critical role in the development of an environmentally friendly and resource-efficient society. Taking the pilot communities of LVR sorting in Xiamen as a case study, we analyzed the composition, carbon emission characteristics, and carbon reduction potential of MSW LVRs based on the IPCC inventory guidelines. The results indicated that: (1) Diverse economic levels resulted in significant differences in LVR composition between communities, where waste plastic comprised the highest proportion (52.62%-58.40%), followed by waste paper (16.42%-19.29%) and waste glass (8.80%-11.58%), with the remainder being waste ceramics, waste textiles, and impurities. (2) Different scenarios were set based on LVR sorting rates, with net carbon emissions decreasing from 645.86 kg/t in Scenario One (incineration + landfill) to 374.24 kg/t in Scenario Four (30% LVR recycling). (3) Uncertainty analysis showed that in Scenario Four, an 8% increase in incineration energy efficiency and a 20% reduction in product substitution from recycling led to a carbon emission reduction of 239.15 kg/t and an increase of 172.56 kg/t, respectively. (4)When the annual waste incineration amount in Xiamen reached 1. 6137 million tons, 30% LVR recycling from residual waste could reduce carbon emission reduction by 0.927 million tons annually.