A New Design Enhances Hydrogen Production by G. Sulfurreducens Pca Strain in a Single-Chamber Microbial Electrolysis Cell (Mec)

Abstract

Microbial electrolysis cell (MEC) is an innovative and green technology to generate hydrogen from a wide range of renewable energy sources and wastewater. At current stage, the performance of these systems is still far from real-world applications. The most likely limiting factors for successful commercialization of this technology are the large internal resistance, high fabrication and operational costs. The aim of the present study was to enhance hydrogen production, reduce the construction and operational costs in MECs via development of a novel MEC design. A single-chamber membrane-free MEC was designed and successfully produced hydrogen from organic substrate using a pure culture: Geobacter sulfurreducens PCA. The MEC system was operated with Platinum (Pt) cathode at applied voltage range of 0.6 V to 1.1 V. Geobacter sulfurreducens PCA strain and sodium acetate used as inoculum and a fuel sources, respectively. The conductivity of electrolyte solution in the MEC was 4.5 mS/cm. Due to an improved the MEC reactor architecture, the maximum hydrogen production rate (HPR) of 3.67 ± 0.03 m3 H2 /m3 d with volumetric current density (IV) of 293.73 ± 1.18 A/m3 was achieved under an external applied voltage (Eap): 1.1 V. The highest overall hydrogen recovery ( ) and overall energy efficiency ( ) were 91.80 ± 1.06% and 66.97 ± 0.09%, respectively.

Microbial Electrochemical Technologies

“…In general, the essential components for the construction and operation of an MEC include a power supply with constant DC source typically between 0.2-0.8V, a microbial enriched anode, a catalyzed cathode (e.g., Pt catalyzed cathode) and a well-designed gas collection system. Different architecture exists (Kadier et al 2016b;Kadier et al 2017c) and they are basically optimized for the process/application that the MECs is built on but important parameters considered include anode-cathode distance, flow rates and configuration and presence/absence of a membrane. Recent studies Kadier et al 2017c) have confirmed that a single-chamber MEC is cost-effective and lead to an increase in the coulombic efficiency (CE) of the entire process.…”

“…Different architecture exists (Kadier et al 2016b;Kadier et al 2017c) and they are basically optimized for the process/application that the MECs is built on but important parameters considered include anode-cathode distance, flow rates and configuration and presence/absence of a membrane. Recent studies Kadier et al 2017c) have confirmed that a single-chamber MEC is cost-effective and lead to an increase in the coulombic efficiency (CE) of the entire process.…”

An overview of microbial electrolysis cell configuration: Challenges and prospects on biohydrogen production

“…It has been reported that single chamber membrane free MEC with graphite brush anode with closer electrode spacing achieved a maximum hydrogen production rate of 3.12 ± 0.02 m 3 H 2 /m 3 reactor/d at an applied voltage of 0.8 V 53 . Use of Geobacter sulfurreducens strain as a medium has improved the performance by minimizing the electrode spacing and internal resistance at 1.1 V 54,55 . The performance of the system was generally determined by changes toward the applied voltage 56 .…”