Role of the organic loading rate and the electrodes’ potential control strategy on the performance of a micro pilot tubular microbial electrolysis cell for biogas upgrading

An innovative biogas upgrading process consists in the utilization of a microbial electrolysis cell (MEC) which biocathode performs bioelectromethanogenesis reaction reducing CO2 into CH4 while an additional removal mechanism sorption as HCO3−, due to alkalinity generation catholyte. Here, two chamber 12-liter tubular MEC has been developed upgrade by using bioelectrochemical organic matter oxidation at anode partially sustain energy demand process. In MEC, electroactive microorganisms’ selection was obtained polarizing + 0.2 V vs. SHE (Standard Hydrogen Electrode). Under this condition, three values applied loading rate (OLR) have investigated. Once best OLR selected 2.55 gCOD/Ld, potentiostatic control switched from cathode. As reported previous experiment, shift resulted sharp decrease process’ consumption thanks minimization anodic overpotential. Moreover, different runs were conducted with cathodic potential controlled −1.3 V; −1.8 −2.3 investigate performances abatement. The lowest for during vs condition 0.5 kWh/Nm3 removed CO2. Those results indicate that switch cathode permits minimize micro pilot having configuration.