Abstract
Landfills emit biogenic CH4 with which green H2 can be produced. However, in developing countries, its territorial potential is unknown. This study presents the first site-resolved national assessment of that potential, with cost and carbon intensity, in Colombia. The 248 disposal sites active in 2024 were analyzed. The CH4 emissions were estimated with a first-order decay model according to the recommendations of the Intergovernmental Panel on Climate Change (IPCC) and the United States Environmental Protection Agency (US EPA). Catalytic reforming and electrolysis projects were evaluated, with Monte Carlo propagation. Through reforming, production was estimated at 76\( kt_{H_{2}} \)/yr if these sites keep receiving waste, and at 46\( kt_{H_{2}} \)/yr if they close when the current licenses expire, whereas through electrolysis, production was estimated at up to 23\( kt_{H_{2}} \)/yr. The estimates indicated that 90% of the national potential is concentrated in 30 landfills, and that 67% of the H2 via reforming (23-89%) costs less than 3USD/\( kt_{H_{2}} \). The CH4 slip proved decisive for the carbon intensity, 0.74\( kg_{CO_2}e \)/\( kt_{H_{2}} \) for reforming and 2.9\( kg_{CO_2}e \)/\( kt_{H_{2}} \) for electrolysis. Capturing the biogenic CO2 generated in reforming would reduce its carbon intensity to -4.1\( kg_{CO_2}e \)/\( kt_{H_{2}} \), provided that the transport and storage of CO2 exist.