Techno-economic analysis of solvent-based biogas upgrading technologies for vehicular biomethane production: A case study in Prados de la Montaña landfill, Mexico City

Abstract

This study examines the feasibility of utilizing biogas from the Prados de la Montaña landfill (PML) in Mexico City to produce vehicular biomethane. Five solvent-based biogas upgrading technologies are analyzed: water scrubbing (WS), propylene carbonate (PC), dimethyl ether of polyethylene glycol (DPEG), monoethanolamine solution (MEA), and potassium carbonate solution (K2CO3). Process modeling and economic analysis are conducted, focusing on the levelized cost of energy (LCOE) as a comparative indicator. The results indicate that the quality and production capacity of biomethane are comparable across all evaluated technologies. The carbon capture system, which significantly impacts the LCOE, represents the largest component cost of the biogas upgrading plant. Among the case studies, the PC solvent demonstrates the most favorable economic performance ($14.5/MMBTU), followed by the solvents K2CO3, DPEG, and WS, which exhibit similar LCOE values ($17.1–17.5/MMBTU). Conversely, the MEA solvent exhibits the highest cost ($20.3/MMBTU). While these LCOEs exceed the historical average cost of natural gas in the market, the PC solvent remains competitive at a carbon tax price ≥ $9.6/tCO2eq. In conclusion, the commercial viability of producing vehicular biomethane at PML using these technologies is primarily dependent on the projected price of imported natural gas and the carbon tax.