Biogas upgrading by electromethanogenesis using a microbial electrolysis cell

Abstract

Bioelectrochemical systems (BES) use microorganisms attached to one or both electrode(s) to catalyse oxidation and/or reduction reactions. A BES is called Microbial Electrolysis Cell (MEC) when external energy is supplied to promote a thermodynamic non spontaneous reaction. These systems have emerged as a highly versatile technology that allows the coupling of wastewater treatment to the production of chemical compounds and energy carriers. In the anode compartment of a MEC, oxidation reactions take place, producing protons and electrons. The electrons are conducted to the anode and flow through an external electrical circuit to the cathode, while the protons and the cations migrate to the cathodic compartment through the cationic exchange membrane placed between both compartments to maintain electroneutrality