Linking internal resistance with design and operation decisions in microbial electrolysis cells

• Published in: Environment international Vol. 126; no. C; pp. 611 - 618
• Main Authors: Miller, Andrew, Singh, Lakhveer, Wang, Luguang, Liu, Hong
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier Ltd 01.05.2019; Elsevier
• Subjects: Biohydrogen production; ENVIRONMENTAL SCIENCES; Environmental Sciences & Ecology; Internal resistance; Microbial electrolysis cell; Microbial electrolysis cell; Internal resistance; Biohydrogen production
• ISSN: 0160-4120; 1873-6750
• DOI: 10.1016/j.envint.2019.02.056

The distribution of internal resistance in most microbial electrolysis cells (MECs) remains unclear, which hinders the optimization and scaling up of the technology. In this study, a method for quantifying the effects of design and operation decisions on internal resistance was applied for the first time to MECs. In typical single chamber MECs with carbon cloth electrodes, the internal resistance was distributed as follows: 210 Ω cm2 for anode, 77 Ω cm2 for cathode, and 11 Ω cm2 M for solution. While varying the spacing of the electrodes (<1 cm) had little effect on MEC performance, inducing fluid motion between the electrodes decreased the internal resistance of all MEC components: 150 Ω cm2 for anode, 47 Ω cm2 for cathode, and 5.3 Ω cm2 M for solution. Adjusting the anode to cathode surface area ratio, to balance the internal resistance distribution, resulted in a significant improvement in performance (47 A/m2 current density, 3.7 L-H2/L-liquid volume/day). These results suggest that the quantification of the internal resistance distribution enables the efficient design and operation of MECs. The parameters obtained in this study were also capable of predicting the performance of MECs from some previous studies, demonstrating the effectiveness of this method. •A method was developed to quantify the internal resistance distribution in MECs.•The specific resistance of anode was about 3 times of the cathode, indicating the system is more anode limiting.•Varying the electrode spacing (<1 cm) had little effect on MEC performance.•Inducing fluid motion between the electrodes decreased the internal resistance of all MEC components significantly.•Balancing the internal resistance distribution resulted in a significant improvement in performance.