Assessment of the Sequential Dark Fermentation and Photofermentation of Organic Solid Waste with Magnetite and Substrate Pre-Treatment Aimed at Hydrogen Use
Gabriela Cadete de Souza, Jessica Silva Souza, Isabela Faria Silva, Regina Mambeli Barros, Geraldo Lúcio Tiago Filho, Ivan Felipe Silva dos Santos, Diego Mauricio Yepes Maya, Electo Eduardo Silva Lora, Rafael Silva Capaz, João Victor Rocha de Freitas, Aylla Joani Mendonça de Oliveira Pontes
Abstract
This study examines the enhancement of dark sequential fermentation and photofermentation of organic solid waste using magnetite and substrate pre-treatment for hydrogen production within the context of transitioning to cleaner energy sources, particularly low-carbon hydrogen. Experimental dark fermentation and photofermentation apparatuses were used, utilizing microorganisms to decompose biomass at a mesophilic temperature (35 °C) of Organic Fraction of Municipal Solid Waste (OFMSW), inoculated with UASB sludge and enhanced with magnetite. A dosage of 120 mg/L of magnetite was the most effective, yielding an average value of 4144 mL H2/gVS. Additionally, the analysis revealed that the levelized cost of hydrogen (LCOH) decreases as more organic waste is utilized, making biohydrogen production a sustainable option, reaching USD 5/kg of OFMSW. Ultimately, generating hydrogen from organic waste can help reduce greenhouse gas emissions and promote a cleaner energy matrix.