Assessment of the potential of coprocessing as a destination for municipal solid waste in the state of Minas Gerais, Brazil

Abstract

The current climate crisis has resulted in efforts to reduce greenhouse effect emissions (GEE) both in the industrial and in the public sanitation sectors. In the year of 2022, there were 10 operational cement kilns licensed for coprocessing in the state of Minas Gerais, with a combined production capacity of 18.8 Mt/year. In the same year, 40.2% of the 853 municipalities in the state still disposed of their municipal solid waste (MSW) in irregular dumps and landfills, which corresponds to approximately 2Mt of MSW per year. Given the strong presence of cement industries in the region, the coprocessing of MSW could represent both a useful tool in MSW management and a strategy to reduce the carbon footprint of the sector, as long as the waste characteristics are made adequate to the technical demands of the process. This work assesses different pre-treatment routes in order to prepare MSW for coprocessing in cement kilns. For each scenario, a preliminary analysis of the potential treatment capacity of these wastes by local cement industries is performed. The results indicate that reducing MSW water content, whether through triage or thermal treatment, drastically increases the lower heating value (LHV) and its applicability as an alternative fuel in cement plants. When considering a 25% alternative fuel ratio in cement kilns, up to 590,000 t/year of MSW could be coprocessed in the State of Minas Gerais.