Improvement of biohydrogen production in microbial electrolysis cell (MEC) system by tackling methanogenesis

Department of Chemical Engineering, Faculty of Engineering Universitas Indonesia, Depok 16424, Indonesia

^* Coresponding author: nana@che.ui.ac.id

Abstract

The increasingly adverse effects of climate change caused by a variety of fossil-based fuel demands an alternative to such fuel. Hydrogen is one of the potential renewable fuel that offers numerous advantages compared to its competitors. However, the dominant hydrogen production methods are still energy-heavy and dependent on fossil-based resources. Microbial electrolysis cell or MEC system is one of the leading solution towards replacing conventional hydrogen production method. A persistent downside to this system in the presence of methanogens that consumes the hydrogen product. This research proposes alternative biological method to control the methanogen colony by introducing isolates of denitrifying bacteria to the system which will act as inhibitor to hydrogenotrophic methanogen. The reactor implemented is a single-chambered, membrane-less 20-ml reactor. Net hydrogen yield produced in the cathodic headspace will be analyzed by gas chromatography (GC). Hydrogen yield for reactor with enriched cathode is expected to be higher in comparison to unenriched reactor, as nitrogen oxides produced during the metabolism of the denitrifiers were known to inhibit methanogen growth. Experimental results showed consistent higher H² yield in inoculated reactor compared to control reactor, where in the second cycle H² production increased 100% compared to the control.