Heterogeneous application prospect and techno-economic analysis of hydrogen from wasted activated sludge: Using microbial electrolysis cell

Abstract

The efficiency of hydrogen production from waste activated sludge (WAS) through combining anaerobic digestion and microbial electrolysis cell (AD-MEC) systems has been increasing. With advancements in materials science, the cost of MEC anode materials has decreased, making this technology potentially economically viable. By analyzing data from 3611 centralized wastewater treatment plants (WWTPs) in 276 prefecture-level cities in China, theoretical application scenarios and environmental benefits of hydrogen production in these WWTPs via AD-MEC were evaluated. Additionally, a theoretical economic model is constructed to validate the economic feasibility of AD-MEC technology. The key findings suggested that the theoretical potential for hydrogen production from WAS in China is 152,610.5 tons/year. The amount of CO2 emitted by natural gas, fuel diesel buses, or power electric public transportation could reduce approximately 1.51, 3.2, and 2.4 million tons/year, respectively, through utilizing hydrogen instead of the above energy sources. Due to the broader temperature adaptability of hydrogen fuel cells, this emission reduction effect was more pronounced in colder, high-latitude regions. Economic analysis revealed that, considering sludge reduction, the AD-MEC system could achieved a return on investment of 13%. This study demonstrated that with the rapid progression in urbanization, AD-MEC systems could contribute to reducing WAS treatment costs and providing clean hydrogen for carbon emission reductions in urban areas.