Life-cycle assessment of municipal solid waste management options: A case study of refuse derived fuel production in the city of Brasilia, Brazil

Abstract

In Brazil, municipal solid waste (MSW) is mainly treated by landfilling. The underutilization of solid waste resources, from the viewpoint of their heating value, contributes to increasing greenhouse gas (GHG) emissions and abiotic resources depletion. MSW as a resource, however, is capable of a coupe with the existing demand of the local cement industry as refuse-derived fuel (RDF). This paper analyzes the application of life-cycle assessment as the basis for improved MSW management in the Brasilia, the capital of Brazil. This study compared four scenarios of MSW management, in which three of them are characterized as an expansion of the ongoing practice by incorporating RDF production while another considers only the landfilling of solid waste. The results indicated that the current MSW management system contributes 267.44 Gg CO2-eq/year to GHG emissions, and the study showed that scenarios based on RDF production imply an increase in energy demand, with higher total GHG emissions, compared to the current management practice. However, gains are archived in environmental terms when the avoided emissions resulting from the substitution of fossil fuels are included in the analysis. The production and use of RDF outperformed the conventional systems by providing emission reductions of 2% to about 23%. Besides, this implies that the implementation of RDF oriented management could significantly reduce the impact on current disposal capacity at the local landfill site. From the perspective of impact related to abiotic resource depletion, it has been found that recycling and composting in the current scenario produces a reduction of 0.12 Gg Sb-eq/year. It constitutes a minimal fraction compared to the reduction in fossil fuel when considering the avoided coke extraction, that provides reductions from 3.63 to 13.73 Gg Sb-eq/year. It was concluded that the environmental advantages of RDF base scenarios in this context arise when the assessment is expanded to include the reduction of GHG indirect emissions and the use of resources.