Green hydrogen production from urban waste biogas: An analysis of the Brazilian potential and the process’ economic viability

Abstract

The goal of this research is to pioneeringly assess the Brazilian potential and the economic viability of producing green hydrogen from urban waste using the biomethane steam reforming (BSR) process. Hence, first, it presents the methane and then the hydrogen estimated production of national wastewater treatment plants (WWTPs) and landfills, followed by two uses for their hydrogen potential. At last, it performsthe economic evaluation of both the hydrogen production and its applications. Brazil can produce 4.57 E+08 Nm3H2/y from WWTPs and 2.87 E+09 Nm3H2/y from landfills. The BSR cost range stands at 2.84–1.48 USD/kgH2 for plant sizes of 2.50 E+05–1.45 E+07 kgH2/y. If applied for electricity generation, the WWTPs' hydrogen potential can attend to 52.57% of the Brazilian wastewater treatment sector's demand while avoiding the emission of 4.60 E+04 tCO2e/y. However, the analyzed system for this hydrogen application has not yet reached economic viability. If employed to power fuel cell electric vehicles (FCEVs) following the distribution of 25% for cars and 75% for buses, the landfills' hydrogen potential would enable the replacement of 0.64 and 4.82% of the national car and bus fleet while preventing the emission of 4.76 E+06 tCO2e/y. For the studied systems, the hydrogen selling price, despite being 89.5% higher than diesel prices, could be nearly equivalent to gasoline prices. To conclude, although urban waste cannot be the country's main hydrogen source due to its reduced potential, this study suggests it may be vital for the early development of the green hydrogen economy in Brazil.