Agric & Bioresources Engineering
Permanent URI for this collectionhttp://197.211.34.35:4000/handle/123456789/72
Agric & Bioresources Engineering
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Item Electrochemical Characterization of Stainless-Steel Mesh and carbon-felt Electrodes for Enhanced Power Generation in Terrestrial Microbial Fuel Cells.(School of Physical Sciences, FUTMINNA, 2024-04-24) Simeon, Meshack Imologie; Alaka, Amarachi C.; Daniela, P.; Olalekan, D. AdeniyiTerrestrial Microbial Fuel Cells (MFCs) represent a promising avenue for sustainable energy production, leveraging microbial metabolism to convert organic matter in the soil into electricity. Crucial to MFC performance is selecting electrode materials, which directly interface with electroactive microbes for electron transfer. This study conducts a comparative analysis of surface-modified stainless-steel mesh (SMS) and carbon felt (CF) electrodes in terrestrial MFCs, evaluating their performance metrics and impedance spectroscopy. The SMS electrode, fabricated using the pasting and reinforcement process, demonstrated superior performance with a maximum power of 859 µW compared to the 234 µW power of the commercially available CF electrode. This better performance of the SMS electrode was attributed to its pseudocapacitive behavior, enhancing internal charge storage capacity and overall MFC efficiency. Electrochemical impedance spectroscopy revealed a substantially higher charge transfer resistance (Rct) in the CF electrode, impeding electron transfer processes. Conversely, the SMS electrode exhibited lower Rct and improved diffusion characteristics, facilitating efficient electron transfer and mass transport. Notably, the Rct of the CF electrode was over 40 times higher, while its diffusion coefficient was approximately six times greater compared to the SMS electrode. These findings underscore the significance of tailored electrode materials in optimizing MFC performance and emphasize the utility of impedance spectroscopy in elucidating complex electrochemical processes within MFC systems, thus guiding future advancements in sustainable power production in terrestrial MFCs.Item The applicability of the Maximum Power-point of Microbial Fuel Cells: Influence of Potential Scan rate and real-time external Load(international Society for microbial Electrochemistry amd Technology-ISMET, 2021-09-15) Simeon, Meshack Imologie; Freitag, RuthPerformance evaluation of a microbial fuel cell (MFC) is usually done with linear sweep voltammetry (LSV) [1] at a given potential scan rate (PSR) [2]. This evaluation does not often reflect the long-term performance of the MFC under real-time external loads [1]. In this study, the performance of a single-chamber MFC was evaluated with three external loads (1206, 470, and 270 Ohms) calculated from LSV maximum power point (MPP) with three PSRs (0.1, 0.5, and 1 mV/s). The estimated power from the MPP in ascending order of PSR was 61.96, 87.88, and 166.68 mW/m2 at 116.5, 229.6, and 403 mA/m2, respectively. The average power obtained with 1206, 470, and 270 Ohms in the first two hours of operation was 73 + 16.7, 36.3 + 42, and 88.5 + 120.1 mW/m2 at current densities of 124.6 + 14.3, 121.2 + 73.4, and 232.6 + 176.2 mA/m2, respectively. The result showed that overestimation was more pronounced at higher PSRs. Although the MFC was initially underestimated at 0.1 mV/s, this PSR more accurately reflects the true and applicable estimate of the long-term performance of the MF vC. These results are explicitly beneficial for ethe lectrochemical estimation of the actual performance of MFCs under real-time external loadsItem Polarization and power density trends of a soil-based microbial fuel cell treated with human urine(2020-03-14) Simeon, Meshack Imologie; Asoiro FU; Aliyu, M; Raji, OA; Freitag, RuthMicrobial fuel cells (MFCs) are bio-electrochemical devices that use microbial metabolic processes to convert organic substances into electricity with high efficiency. In this study, the performance of a soil-based MFC using urine as a substrate was assessed using polarization and power density curves. A single-chamber, membrane-less MFC with a carbon-felt air cathode and a carbon-felt anode fully buried in biologically active soil was constructed to examine the impact of urine treatment on the performance of the MFC. The peak power of the urine-treated MFC was 124.16 mW/m2 and was obtained 24 hours after the first urine addition; a control MFC showed a value of 65.40 mW/m2 in the same period. The treated MFC produced an average power of 70.75 mW/m2 up to 21 days after the initial urine addition; the control MFC gave an average value of 4.508 mW/m2 over the same period. The average internal resistances of the treated MFC and the control MFC obtained after the initial treatment were 269.94 and 1627.89 Ω, respectively. This study demonstrates the potential of human urine to reduce internal losses in soil MFCs and to provide stable power densities across various external resistors. These results are propitious for future advancements in soil MFCs for power generation, utilizing human urine (a readily available source of nutrients) as a substrate.