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.