Assessment of the Sequential Dark Fermentation and Photofermentation of Organic Solid Waste with Magnetite and Substrate Pre-Treatment Aimed at Hydrogen Use

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.