Development of an Acetate-Fed or Sugar-Fed Microbial Power Generator for Military Bases

Abstract

Abstract : Our main goal is to develop and optimize a microbial fuel cell (MFC) that uses a non-flammable and renewable fuel, such as acetate or sucrose, to be used in future military missions. Thus, we must design an MFC capable of producing high power densities with minimal potential losses. These characteristics would allow the MFC to be feasible and efficient. Our proposed approach is to optimize each component of MFCs and then use these components in novel reactor designs that yield high power densities. We have recently finished the first quarter of the project and are beginning the second one. The goals for the first quarter included: (1) testing anode and anion exchange membrane (AEM) materials, (2) developing a mixed culture for sucrose consumption in an MFC, and (3) completing the design of the MFC modules. The goals for the ongoing second quarter include: (1) optimizing the anode medium for anode-respiring bacteria (ARB) using the PCBIOFILM model and short-term experiments and (2) constructing the MFC modules. We successfully achieved the 3 goals for the first quarter. We tested graphite and stainless steel as anode materials for ARB growth, showing the greater suitability of carbon fibers as anode material (Figures 1-2). We also tested different commercially available AEMs to select for the most suitable for our MFC modules (Figure 3 and Table 1). Using these selected materials, we are underway of constructing our first MFC module (Figure 5). We also used an enriched consortium of homo-acetogenic bacteria to consume sucrose and convert it into volatile fatty acids (VFAs) that are easily consumed by ARB (Figure 4). This culture produces mainly lactate and acetate as fermentation products and is ready for test in the MFC modules.