Energy uses and valorization of landfill gas in a developing country: Mexico’s case

The management of landfill gas (LFG) is a main issue in the final disposal of municipal solid waste (MSW), as LFG is an important source of greenhouse gas emissions. This management is more challenging in regions with developing countries, such as Latin America, where final disposal sites (FDS) lack adequate practices and infrastructure, although FDS are the main strategy of MSW management. The present study assessed the environmental and economic impact of LFG valorization in 198 sanitary landfills in Mexico, which is a developing country. The valorization scenarios included electricity generation, use as an industrial fuel, and upgrading to bio-compressed natural gas (bio-CNG). The environmental and economic impacts were evaluated for each scenario, using the single-issue method of IPCC 2021 GWP 100a and the net income, respectively. The results indicated that the use of LFG as a replacement for gasoline combined with electricity generation can mitigate up to 0.547 kg of CO 2 eq per m 3 of captured LFG, which presents the highest environmental gains of all scenarios assessed. The economic evaluation showed negative net income in all scenarios. Sensitivity analyzes were performed to evaluate the influence of some strategies to finance and incentive LFG energy use projects. The results showed a feed-in tariff policy of up to 80% in for the bio-CNG scenario, could more effectively secure the financial feasibility of the projects than an emissions trading system, due to the current context of energy market in Mexico. The findings suggest that Mexico and other developing countries may benefit from the diversification of the energy uses of LFG, contributing to the decarbonization of industry and transport sectors.