Briefing: Landfill mining for energy recovery in tropical developing countries

This paper discusses landfill mining (LM) and uses data from tropical landfills in a preliminary analysis of its applicability. It is shown that there is a tendency of concentration of components with high calorific values over time, the contrary occurring with the municipal solid waste (MSW) water content, w, which is normally smaller for aged samples compared to that for fresh ones. This encourages LM adoption in various landfills since more energy can be recovered from MSW with the use of thermal recovery methods (TRMs) and less energy is necessary for MSW drying. Furthermore, it is demonstrated that 4–6 years is enough for most biological processes to occur in the field in tropical regions, making the use of LM possible in few years after landfill closing. The use of TRMs such as gasification is interesting because the produced hydrogen gas (H₂) can be used for electrical power generation similar to methane (CH₄). However, the use of thermal energy recovery methods in MSW components can result in dangerous atmospheric emissions, which must be controlled and rigorously monitored, as well as the stability of the MSW mass during the excavation process.