Discover insights from thousands of peer-reviewed papers on microbial electrochemical systems
Nurul Najwa Adam Malik, Mohammad Mirza Mohammad Faizal, Husnul Azan Tajarudin et al.
Journal of Physics: Conference Series · 2021
Abstract Electricity constitutes one of the basic energies of our everyday life and approximately 14 % of the global population does not have the access to electricity. An abundance of waste is generated daily wherein food waste constitutes 45 % of the composition. A mediator-less and membrane-less single-chambered microbial fuel cell (ML-MFC) has the potential to serve as a cost-effective solution for food waste treatment and electricity power generation at no additional cost for the substrate. Food waste from E-Idaman Sdn. Bhd. Kedah was utilised in this study to generate electrical energy while focusing on the effect of different yeast extract concentrations on the performance of the ML-MFC. Electrogenic bacterial (EB) culture employed in this study acted as a catalyst for the power generation and was isolated from a previous ML-MFC study. The proximate analysis of food waste observed carbon constituting the greatest composition at 30.02 %. From the conducted preliminary study which compared three different strains of EB to be introduced in the ML-MFC, Bacillus subtillis sp . exhibited the highest specific growth rate, μ , (0.117 g. L −1 /h) and shortest doubling time, Td , (5.93 h). One-factor-at-a-time (OFAT) method was utilised to evaluate the performance of the ML-MFC. 15 g/L yeast extract concentration obtained the greatest power density (628.05 × 10 6 mW/m 2 ), substrate degradation efficiency (12.3 %), COD removal (99 mg/L) and biomass (44.32 mg/L). This showcased that the addition of extra yeast extract concentration into the food waste had boosted the efficiency of EB’s growth resulting in greater consumption of carbon source (removed COD value; bioremediation) in the food waste.
Y. Reyes-Vidal, J. López-Maldonado, F. Castañeda et al.
International Journal of Chemical Reactor Engineering · 2018
Abstract A theoretical model that describe the effect of design and operational conditions on current density distribution in a bioelectrochemical reactor used as microbial electrolysis cell (MEC) is described in this study. This model is proposed considering an approach where a direct electron transfer mechanism from the biofilm to the electrode surface takes place (mechanism present in most of microbial systems) and is governed by a dual donor-acceptor Nernst-Monod bioelectrochemical kinetic expression. The bioelectrochemical reactor is modelled considering two flow electrochemical reactor designs (a reactor design based in literature reports and a modified system proposed by the authors) operating at different flow inlet velocities and electrical overpotentials. Results obtained from the numerical solution shows that flow distribution is an essential aspect that impact the reactor performance, since concentration profiles and electrical potential-current distributions are strongly dependent on flow regime. Modified inlet configuration displays a more homogeneous fluid distribution and this behavior directly affects the mass transport and current density performance, as a result higher current density values are obtained for such configuration. Finally, it is expected that the information obtained from the analysis carried out in this report will provide us with a theoretical basis to realize the construction of a bioelectrochemical reactor prototype to develop the MEC concept.
Y Z Jin, Y C Wu, B Q Li et al.
IOP Conference Series: Earth and Environmental Science · 2019
Abstract We use anhydrous sodium acetate, glucose, lactose and Colocasia antiquorum Schott as anode substrate to study the periodic curve of battery voltage and stable output voltage of different substrates, The results showed that the four kinds of microbial fuel cells with sodium acetate, glucose, lactose and pretreated Colocasia antiquorum Schott as anode substrate had the following power generation periods: 23.98 d, 20.15 d, 18.84 d and 23.52 d, respectively, and the stable voltage at the two ends of the resistance of microbial fuel cells with four different anode substrates are 0.77 V, 0.75 V, 0.65 V and 0.70 V respectively. We found at the same carbon source concentration, MFC with sodium acetate as the substrate has the best electricity production characteristics. When the pretreated Colocasia antiquorum Schott is used as anode substrate, the time for cell voltage to rise from initial value to stable value is the shortest, and as a carbon source, it can also play a dominant role in the process of electric energy collection and utilization.
Yucui Shi, Gang Tang, Shaohong You et al.
Applied Sciences · 2023
Cr (VI) is hazardous to humans and our environment. Leersia hexandra Swartz (L. hexandra) is the first wet chromium hyperaccumulator found in China. This study constructed the L. hexandra constructed wetland-microbial fuel cell (CW-MFC) system to treat Cr (VI) wastewater. It also determined the effects of different dissolved oxygen (DO) concentrations on power generation, pollutant removal, and Cr (VI) reduction. Cathode aeration promoted the voltage output and pollutant removal of the L. hexandra CW-MFC when the DO concentration was 4.5 mg·L−1: the highest voltage was 520 mV, the chemical oxygen demand (COD) removal rate was 93.73%, and the Cr (VI) removal rate was 97.77%. Moreover, the increase in the DO concentration improved the absorption of heavy metal Cr by the substrate and L. hexandra, and promoted the transformation from Cr (VI) to Cr (III). Chromium mostly exists as a residue with low toxicity and low mobility in L. hexandra and the substrate. This proves that the increased DO concentration promotes the redox reaction in the system and plants, reducing Cr (VI) to Cr (III). At the same time, the key micro-organism Geobacter that enhances the performance of the system and Cr (VI) reduction was found. The research results can provide a reference for the subsequent CW-MFC treatment of actual Cr-containing wastewater.
Samsudeen Naina Mohamed, Radhakrishnan Thota Karunakaran, Matheswaran Manickam
Environmental Progress & Sustainable Energy · 2017
Distillery wastewater is an important potential sources for electricity generation using Microbial Fuel Cell (MFC) because of it has high content of organic waste and can be easily degraded. This study investigated the effect of feed pH and buffering conditions on electricity production and treatment efficiency using distillery wastewater as a substrate in MFC. The anodic chamber was operated with diluted distillery wastewater (4000 ± 20 mg COD/L) at various pH between 5.4 and 10 while the cathode chamber was maintained at pH 7.5. The MFC peak power density of 168 mW/m 2 (580 mA/m 2 ) with COD, color and TDS removal efficiency of 68.2, 26.4, and 15.4%, respectively was achieved at pH 8. Cyclic voltammetry revealed that an exoelectrogenic activity of microorganism was significantly influenced with respect to pH. The effect of buffering salts in the anolyte on MFC performance was also investigated. When the system operating with borate buffer, highest power density of 194.7 mW/m 2 (624 mA/m 2 ) at 100 Ω was achieved. The result indicated that alkaline condition (pH 8) and borate buffer was favored for obtaining maximum power generation and treatment efficiency from distillery wastewater in the MFC. © 2017 American Institute of Chemical Engineers Environ Prog, 37: 663–668, 2018
Areli Ortega-Martínez, Katy Juárez-López, Omar Solorza-Feria et al.
Journal of New Materials for Electrochemical Systems · 2012
The aim of this work was to design and characterize a novel, multiface parallelepiped MFC in the perspective of decreasing the internal resistance (Rint) and increasing the volumetric power (Pv) output. The cell was fitted with a ‘sandwich’ cathode-membrane-anode assemblage in five of its faces, and possessed a ratio electrode surface area-to-volume ξ (csi) of 19 m-1 .
 When the 5 faces of the MFC-P were connected in series, the Rint was 601 Ω with a voltage of 0.52 V. Characterization of the cell with the 5 faces connected in parallel gave a Rint of 62 Ω with a voltage of 0.5 V that corresponded to external resistance of 56 k Ω in the polarization procedure. This result was ascribed to both the changes in cell architecture and decrease of the inter-electrode distance as well as the parallel connection. The Pv of the new MFC-P achieved values of 62 and 570 mW/m3 for series and parallel connection, respectively.
 Molecular ecological techniques were used to analyze the bacterial diversity of biocatalyst used in new design MFC-P. They showed a low species richness and low-to-moderate evenness. The community consisted primarily of δ-Proteobacteria and Firmicutes, bacteria that are recognized to be capable of exocellular electron transfer.
Jonathan Winfield, Paolo Milani, John Greenman et al.
ECS Meeting Abstracts · 2018
The versatility of Microbial fuel cells (MFCs) has meant that the technology can now branch towards a growing variety of applications. One of the big challenges however, has not been the microbial community but the identification of materials that allow the organisms to thrive and ultimately produce power. Paper has recently been adopted as a viable material that functions both structurally and as the medium for proton exchange. To date; the most reported use for paper-based MFCs has been as a diagnostics tool, however it is highly desirable to develop paper MFCs as lightweight, portable power supplies. In a diagnostic role, the paper MFCs reported have been low-power and short-lived (lasting just minutes) which is not suitable if the role were as power supply. There have been reports of longer-term electrical outputs using paper-based MFCs (with air-cathodes) such as origami stacks 1 and 3D-tetrahedron MFCs 2 . However, in both cases the method for feeding was via careful liquid injection. This is all very well in a lab-based environment but in a real-world scenario MFCs might need activating quickly and without delicate feeding requirements. Here it would be advantageous to simply distribute onto pools of liquid and have them passively intake the fuel. The goal of the current study therefore was to look at paper-based MFCs and investigate whether they might be able to passively intake nutrients from the surrounding environment. Two MFC designs were looked at; the first being flat 2D-MFCs with the anode on the underside of the paper, directly in contact with the liquid and the cathode on top, open to air. The second design was 3D-tetrahedron MFCs constructed from standard copier paper but with an absorbent cellulose material incorporated into the base. For all MFCs, air-cathodes were used without platinum or ferricyanide. For the 2D-flat MFCs, two methodologies were tested; the first was to print electrodes on either side of the paper and the second were hand-made, three-layered structures with conductive latex cathodes painted on one side and a sheet of carbon fibre adhered to the other. Each MFC was approximately 2cm x 4cm. In all experiments, there was no inoculation prior to the MFC being placed on puddles of enriched wastewater. The MFCs with printed electrodes reached peak OCV of 300mV which quickly dropped. In closed circuit the current peaked at 2.4 µA before rapidly declining which is clearly unsuitable for real-world use. The reason for the poor performance was the dissolution of the electrode as the liquid displaced the conductive elements as verified by the significant increase in resistance after use. Further work with printed MFCs will investigate incorporating a stabilising material to prevent the electrodes dissolving. The flat hand-made MFCs fared much better. Interestingly the conductive-latex cathodes were more resistive than the printed ones yet the MFCs were superior and more stable over time. These MFCs climbed and stabilised for 4 days at 11 µW (185mV). Different types of paper were trialled including baking, greaseproof and copier and all performed comparably. Further work will investigate stacking multiple flat-MFCs on single sheets of paper. The simple flat-MFCs are promising but for MFCs operating outside and tapping into nutrients in puddles they should ideally have enclosed chambers housing the anode. To trial this, 3D-tetrahedron MFCs with 15mL volume were set up to sit on pools of liquid with the only method of feeding via capillary motion of the absorbent base. The 3D-MFCs with absorbent bases were compared to MFCs with a waterproof coating over their base. Those with the absorbent bottoms immediately generated a current and continued increasing in power for over 2 weeks peaking and stabilising at 40µW (2.7 W/m 3 ). In addition, when fresh nutrient was added to the reservoir (not directly to the MFCs), they responded almost immediately, a factor that could be advantageous if the role were biosensor. The MFCs with plastic coated bases showed no working voltage throughout the period. The output generated by the MFCs relying on a passive feeding mechanism is comparable to that produced by the same MFCs with sealed bases from a previous study (where injection feeding took place 2 ). This output is sufficient to initiate a power management system and broadcast radio signals. These findings are an exciting development because lightweight paper-MFCs could potentially be dropped onto puddles of organic liquid, passively sucking up nutrients from the environment and subsequently broadcasting distress signals. References 1 Fraiwan et al., (2016) Biosens Bioelectron 85: 190-197 2 Winfield et al., (2015) J Mater Chem A 13: 7058-7065
Hodaka Shimohata, Dang Nguyen, Kozo Taguchi
Resourceedings · 2023
Bamboo is a fast-growing plant in Southeast Asia, Africa, and Latin America. Due to its rapid growth, bamboo is considered a problem because it rapidly invades forested areas and alters the original ecosystem. On the other hand, it is regarded as a material that is readily available and very accessible in many countries and has great potential for both ecological and social purposes. Therefore, bamboo was employed as the material for the electrodes of microbial fuel cells in this study. Typically, biochar used for electrodes is chemically activated to remove impurities and increase its surface area. However, chemical treatment of biochar can have a negative impact on the activity of microorganisms. The Bamboo charcoal powder, prepared by heat-treating powdered bamboo for one hour under air at 500°C, contained about 75% carbon and had a porous structure. Therefore, the material could be used as an electrode material for microbial fuel cells without complicated and time-consuming treatment processes. Some of these treatment processes include chemical treatment, and chemically treated biochar may impact the environment. Bamboo charcoal, which does not require this chemical treatment process, is effective as an electrode material for microbial fuel cells. Bokuju, a common kind of drawing ink in Japan and mainly composed of carbon black, was used as a binder for the prepared bamboo charcoal. The reason for using powdered bamboo charcoal with Bokuju is that it is easier to obtain a solid electrode shape by a drying process. We used this electrode in a floating microbial fuel cell and optimized the ratio of Bamboo charcoal powder and Bokuju in the electrode. By evaluating the performance of the microbial fuel cell using the Bamboo charcoal Bokuju electrode, we were able to improve the effectiveness of the electrode material.
Seyed M Ghoreyshi, Meinhard T Schobeiri
Proceedings of the Institution of Mechanical Engineers, Part A: Journal of Power and Energy · 2020
In the Ultra-High Efficiency Gas Turbine Engine, UHEGT (introduced in our previous studies) the combustion process is no longer contained in isolation between the compressor and turbine, rather distributed within the axial gaps before each stator row. This technology substantially increases the thermal efficiency of the engine cycle to above 45%, increases power output, and reduces turbine inlet temperature. Since the combustion process is brought into the turbine stages in UHEGT, the stator blades are exposed to high-temperature gases and can be overheated. To address this issue and reduce the temperature on the stator blade surface, two different approaches are investigated in this paper. The first is indexing (clocking) of the fuel injectors (cylindrical tubes extended from hub to shroud), in which the positions of the injectors are adjusted relative to each other and the stator blades. The second is film cooling, in which cooling holes are placed on the blade surface to bring down the temperature via coolant injection. Four configurations are designed and studied via computational fluid dynamics (CFD) to evaluate the effectiveness of the two approaches. Stator blade surface temperature (as the main objective function) along with other performance parameters such as temperature non-uniformity at rotor inlet, total pressure loss over the injectors, and total power production by rotor are evaluated for all configurations. The results show that indexing presents the most promising approach in reducing the stator blade surface temperature while producing the least amount of total pressure loss.
Sofia Babanova, Jason Jones, Sujal Phadke et al.
Water Environment Research · 2019
Abstract Microbial fuel cells (MFCs) have long held the promise of being a cost‐effective technology for the energy‐neutral treatment of wastewater. However, successful pilot‐scale demonstrations for this technology are still limited to very few. Here, we present a large‐scale MFC system, composed of 12 MFCs with a total volume of 110 L, successfully treating swine wastewater at a small educational farm. The system was operated for over 200 days in continuous mode with hydraulic residence time of 4 hr. Very stable electrochemical and waste treatment performance was observed with up to 65% of chemical oxygen demand (COD) removed and a maximum treatment rate of 5.0 kg COD/m 3 .day. Robust microbial enrichment was performed and adapted to metabolize and transform a diversity of compounds present. The Net Energy Recovery (NER = 0.11 kWhr/kg COD) is not only competitive with conventional cogeneration processes, but is in fact sufficient to sustain the operational energy requirements of the system. Practitioner points This study demonstrates the design and operation of a large‐scale microbial fuel cells (MFC) system for continuous treatment of swine wastewater. The system achieved a high chemical oxygen demand removal rate within a short hydraulic residence time. This study moves one‐step closer to applying MFC technology for real wastewater treatment.
Yucui Shi, Gang Tang, Shaohong You et al.
Frontiers in Environmental Science · 2022
Cr(VI) is toxic to the human body and environment. As a suitable wastewater treatment with low energy requirement technology, constructed wetland-microbial fuel cells (CW-MFCs) can treat Cr(VI) wastewater while generating electricity. In this study, CW-MFC and constructed wetland systems were developed to purify Cr(VI) wastewater. The removal mechanism of Cr(VI) was examined by electron paramagnetic resonance (EPR), X-ray photoelectron spectroscopy (XPS), and Fourier transform infrared spectroscopy. The results demonstrated that the average pollutant removal efficiency of the CW-MFC system is 2.99–8.13% higher than that of the constructed wetland system, and the maximum power density is 505.61 mW m −2 . Moreover, the XPS and EPR analyses demonstrated that Cr in substrates and Leersia hexandra Swartz primarily is in the form of Cr(III). Moreover, in plants and substrates, the Cr(III) content of the CW-MFC system was higher than that of the control, and the bioconcentration and translocation factors were 0.23 and 0.05 higher than those in the control group, respectively. Therefore, the CW-MFC system can efficiently remove Cr(VI) and promote the accumulation and transport of Cr. Microbial community diversity in the CW-MFC was significantly higher than CW. The abundance of electrogenic bacteria Geobacter and metal dissimilatory reducing bacteria Acinetobacter in CW-MFC is higher than that in CW. To summarize, the study results provide a theoretical basis for the mechanism study of Cr(VI) wastewater treatment using CW-MFC systems.
Kieu Thi Quynh Hoa, Phung Minh Hieu, Vy Tuan Anh et al.
Vietnam Journal of Biotechnology · 2022
Sulfate/sulfide-containing wastewater is a widespread environmental contaminant resulting from human activities. These pollutants have negative impact on natural ecosystems and human beings. Biological sulfate/sulfide removal can be achieved by reducing sulfate to sulfide with sulfate-reducing bacteria and then oxidizing sulfide to elemental sulfur (So) with sulfide oxidizing bacteria. In sulfate/sulfide contaminant wastewater lacking electron acceptor for sulfide oxidization, excess sulfide will be produced and accumulated in the treatment system. Therefore, microbial fuel cells (MFCs) have been shown to be a promising technique for the removal of sulfate/sulfide pollutants in wastewater. In this study, a lab-scale MFCs has been developed based on the activity of sulfate-reducing bacterium Desulfovibrio. sp. The results showed that sulfate and sulfide removal efficiencies of 74 - 82% (78 ± 2,5%) and 80.8 - 89.1% (~85,6 ± 3,1%) were achieved, respectively, from the 5th day to the 14th day of operation. The voltage of 0.02V and power density of 7.2 to 7.8 mW/m2 was obtained. In this study, sulfide oxidizing-based MFC integrated with sulfate-reducing bioreactor, representing the feasibility of simultaneous sulfate/sulfide pollutants removal and electricity generation in MFCs. This provides a promising treatment system to scale up for its actual applications in sulfate/sulfide removal.
Banu Taşkan, Ergin Taşkan, Halil Hasar
Environmental Progress & Sustainable Energy · 2020
Abstract The aim of this study is to increase the electricity generation capacity of sediment microbial fuel cell (SMFC) using sewage sludge as a substrate source in anode media via an attractive electrode material. For this purpose, several electrochemical and molecular techniques have been employed to evaluate the performance of SMFC. The max power density and charge transfer resistance of SMFC running on sewage sludge were 187 mW/m 2 and 84.7 Ω, respectively. The polymerase chain reaction‐denaturing gradient gel electrophoresis (PCR‐DGGE) analysis indicated that bacteria in anode biofilm belonged to the Clostridia , d‐proteobacteria , g‐proteobacteria , and b‐proteobacteria . Scanning electron microscopy and fluorescence in situ hybridization observations demonstrated that a viable biofilm was formed on the anode surface and the abundance of bacteria was significantly higher than archaea. Consequently, this study showed that sewage sludge could be used as a substrate in the anode media of SMFC for producing high power density.
D Chatzikonstantinou, A Tremouli, K Papadopoulou et al.
Waste Management & Research: The Journal for a Sustainable Circular Economy · 2018
In this study, the use of a dual-chamber microbial fuel cell for the production of bioelectricity from a food residue biomass (FORBI) product was investigated. Food residue biomass was produced by drying and shredding the pre-sorted fermentable fraction of household food waste collected door-to-door in the Municipality of Halandri, Athens, Greece. Different organic loads of food residue biomass expressed as chemical oxygen demand (COD) were examined (0.7, 0.9, 1.4, 2.8, 6 and 14 g COD L −1 , respectively). It was observed that an increase of the initial concentration of the final extract resulted in a corresponding increase in the operating time. The microbial fuel cell potential increased from 33.3 mV to 46 mV as the concentration was increased from 0.7 to 14 g COD L −1 . The best performance in terms of maximum power density (29.6 mW m −2 ) corresponding to a current density of 88 mA m −2 was observed for 6 g COD L −1 . Setting the external resistance at its optimal value (R ext = 2 kΩ) as determined by polarisation experiments, P yield drastically increased to 13.7 and 17.3 Joule (g FORBI) −1 in two consecutive cycles. The results demonstrate that readily biodegradable substrates, such as food residue biomass, can be effectively used for enhanced bioelectricity harvesting in a microbial fuel cell.
Anna Salvian, Daniel Farkas, Marina Ramirez-Moreno et al.
npj Clean Water · 2024
Abstract Efficient wastewater treatment monitoring is vital for addressing water scarcity. Microbial fuel cells (MFCs) have emerged as real-time biosensors for biochemical oxygen demand (BOD) in urban wastewater. Discrepancies in signal generation may arise due to changes in the composition and metabolism of mixed-culture electroactive biofilms stemming from different wastewater compositions. In this study, 3D-printed MFC-based biosensors were employed to assess the BOD of sterile complex artificial wastewater and untreated urban wastewater. Alterations in the microbial composition of the anode were evaluated using 16S rRNA sequencing and metagenomics analysis. Results show that MFC-based biosensors can be effectively recalibrated for diverse types of wastewater, maintaining consistent sensitivity (0.64 ± 0.10 mA L mg −1 m −2 with synthetic wastewater and 0.78 ± 0.13 mA L mg −1 m −2 with urban wastewater) and limit of detection (49 ± 8 mg L −1 for synthetic wastewater and 44 ± 7 mg L −1 for urban wastewater). Crucially, pre-sterilization, conductivity adjustments, and nitrogen purging of wastewater are not required before its introduction into the biosensor. However, the presence of native aerobic microorganisms in the wastewater might affect the current output. Metagenomics and taxonomic analyses revealed that the alterations in biofilm composition are predominantly in response to the varied chemical and microbiological compositions of different substrates. Despite variations in anodic biofilm composition, the MFC-based biosensor maintains a relative error comparable to the standard BOD test. This highlights the resilience and flexibility of the biosensor when directly used with a variety of wastewater types before full biofilm adjustment.
Henan Li, Guohong Liu, Chao Li et al.
Research Square · 2021
Abstract Six 60-L benthic microbial electrochemical systems (BMES) were built for the bioremediation of river sediment. Carbon mesh anodes with honeycomb-structure supports were compared with horizontal anodes, and the system was tested using different cover depths and anode densities. The pollutant removal, electricity generation, and electrochemistry of the six BMES with different anodes was examined using the Ashi River (Harbin, China) as a case study. Total organic carbon (TOC) and total nitrogen (TN) removal from sediments in BMES with three-dimensional anodes were 20%~30% and 20%~33% higher for the other reactors. Moreover, the honeycomb-structure of the anode also resulted in higher power density and improved humus removal.
Segundo Rojas Flores, Orlando Pérez-Delgado, Nazario Naveda-Renny et al.
Environmental Research, Engineering and Management · 2022
The large amount of molasses that are generated in sugar-processing companies are not always redistributed for commercialization in by-products. Because of this, the present research uses these wastes as fuel in low-cost, lab-scale, single-chamber microbial fuel cells. Zinc and copper electrodes were used as electrodes and 100 mL of molasse in the chamber as fuel, managing to generate current and voltage peaks of 1.73 ± 0.13 mA and 0.953 ± 0.142 V. In monitoring the conductivity of the substrate, a maximum peak of 111.156 ± 8.45 mS/cm was observed, and a slightly acidic pH was observed throughout the monitoring. It was possible to obtain a power density of 5.45 ± 0.31 W/cm2 for a current density of 308.06 mA/cm2, while the yeast count showed a logarithmic curve throughout the monitoring. Finally, the molecular technique identified 100% of the special C. boidinii present in the anodic electrode. This research will give great benefits to sugar companies because they will be able to generate electricity using the molasses that cannot generate by-products.
I. Khazaee, M. Mohammadiun
International Journal of Applied Mechanics and Engineering · 2013
A complete three-dimensional and single phase model for proton exchange membrane (PEM) fuel cells was used to investigate the effect of using different channels geometry on the performances, current density and gas concentration. The proposed model was a full cell model, which includes all the parts of the PEM fuel cell, flow channels, gas diffusion electrodes, catalyst layers and the membrane. Coupled transport and electrochemical kinetics equations were solved in a single domain; therefore no interfacial boundary condition was required at the internal boundaries between cell components. This computational fluid dynamics code was employed as the direct problem solver, which was used to simulate the three-dimensional mass, momentum, energy and species transport phenomena as well as the electron- and proton-transfer process taking place in a PEMFC. The results showed that the predicted polarization curves by using this model were in good agreement with the experimental results and a high performance was observed by using circle geometry for the channels of anode and cathode sides. Also, the results showed that the performance of the fuel cell improved when a rectangular channel was used.
Tukendra Kumar, Satya Eswari Jujjavarapu
Journal of Chemical Technology & Biotechnology · 2023
Abstract BACKGROUND The experimental process for optimizing microbial fuel cell (MFC) design under different electrode geometries is restricted. An MFC can be defined as a bio‐electrochemical system (BES) that facilitates the direct conversion of the chemical energy stored in organic matter into electrical energy by harnessing the metabolic activity of microorganisms. Computational fluid dynamics (CFD) tools allow the simulation and evaluation of electro‐analysis phenomena such as cyclic voltammetry and chemical reactions, which can help the optimization of the BESs. In this study, MFC is designed to provide the maximum peak current and efficiency for the applied voltage on various working (or anode) electrode geometries (i.e. hexagonal, square, pentagonal, circular, triangular, rectangular, and rhombus). RESULTS The CFD simulation results demonstrate that a configuration with a larger perimeter value and surface area (i.e. hexagonal design) of the working electrode shows a higher peak current (2422.75 mA) than other configurations. The experimental findings supported the simulation result and reveal that a hexagonal electrode containing a MFC setup produces a maximum power density of 22.41 ± 0.32 mW m −3 and a current density of 41.58 ± 0.35 mA m −2 . The MFC operation demonstrated adequate bioelectricity generation of 540 ± 03 mV on Day 4 of operation at 1000 Ω. Additionally, maximum reduction in chemical oxygen demand (76.13 ± 0.5%) and coulombic efficiency (76.03 ± 0.4%) was achieved for synthetic wastewater using a hexagonal MFC. CONCLUSION Based on these fundamental discoveries, the CFD simulation and its experimental validation considerably drag focus toward the possibility of employing COMSOL Multiphysics software for system improvement of different MFC system applications. © 2023 Society of Chemical Industry (SCI).
Siti Kudnie Sahari, Mohd. Zulhilmi Firdaus Rosli, Amir Maina Butit et al.
Pertanika Journal of Science and Technology · 2022
This paper presents a Single-chamber Microbial Fuel Cell (SMFC) design by utilizing soil as a substrate with two sets of electrode combinations, which are graphite-activated carbon and copper-zinc of different sizes. It was found that graphite and activated carbon produced greater power density compared to copper and zinc. Moreover, it was observed that the graphite-activated carbon cloth electrode with a bigger surface area of 51cm2, resulted in a higher power density of 904mW/m2. To further improve the voltage production of this model, four SMFCs were stacked in series and connected to a DC-DC boost converter to increase the voltage to 1.482 V for the copper-zinc electrode and 1.722 V for the graphite-activated carbon electrode, respectively, which was sufficient to light up an LED light.
Xiaoyuan Zhang, Qiuying Wang, Cheng Tang et al.
Small · 2019
Abstract Microbial fuel cells (MFCs) can convert organics in wastewater directly to electricity, and improving oxygen reduction reaction (ORR) performance is critical to their development and future applications. Electrocatalytic ORR performance is determined by the intrinsic activity and accessible amounts of active sites. A surface nitrogen‐enriched carbon coaxial nanocable (NCCN) is applied as an ORR electrocatalyst and combined with activated carbon (AC) with 80 wt% addition as a carbon–carbon composite air cathode in MFCs. The fully exposed nitrogen active sites of NCCN contribute to the enhanced ORR activity, while the graphitized core affords a rapid pathway for electron transportation. AC serves as a spacer to construct a porous framework with interconnected ion diffusion channels. This cathode thus exhibits a maximum power density of 2090 mW m –2 , 120% higher than commercial Pt/C electrocatalysts, and also 6% higher than the pure NCCN, indicating a synergistic effect between NCCN and AC. A high‐performance NCCN‐AC air cathode with a great promise for future MFC applications is reported and an effective strategy to bridge the electrocatalytic performance from nanomaterials to practical devices is presented.
Chikashi Sato, Wilgince Apollon, Alejandro Isabel Luna-Maldonado et al.
Membranes · 2023
In this study, a microbial fuel cell was integrated into a hydroponic system (MFC-Hyp) using a ceramic membrane as a separator. The MFC-Hyp is a passive system that allows the transport of nutrients from wastewater in the microbial fuel cell (MFC) to water in the hydroponic vessel (Hyp) through a ceramic membrane separator, with no external energy input. The performance of this system was examined using potato-process wastewater as a source of energy and nutrients (K, P, N) and garlic chives (Allium tuberosum) as a hydroponic plant. The results showed that based on dry weight, the leaves of Allium tuberosum grew 142% more in the MFC-Hyp than those of the plant in the Hyp without the MFC, in a 49-day run. The mass fluxes of K, P, and NO3−-N from the MFC to the Hyp through the ceramic membrane were 4.18 ± 0.70, 3.78 ± 1.90, and 2.04 ± 0.98 µg s−1m−2, respectively. It was apparent that the diffusion of nutrients from wastewater in the MFC enhanced the plant growth in the Hyp. The MFC-Hyp in the presence of A. tuberosum produced the maximum power density of 130.2 ± 45.4 mW m−2. The findings of this study suggest that the MFC-Hyp system has great potential to be a “carbon-neutral” technology that could be transformed into an important part of a diversified worldwide energy–water–food supply system.
Constantina K. Varnava, Panagiotis Persianis, Ioannis Ieropoulos et al.
Bioprocess and Biosystems Engineering · 2024
Abstract In the present study, the potential of Pseudomonas citronellolis 620C strain was evaluated, for the first time, to generate electricity in a standard, double chamber microbial fuel cell (MFC), with oily wastewater (OW) being the fuel at 43.625 mg/L initial chemical oxygen demand (COD). Both electrochemical and physicochemical results suggested that this P. citronellolis strain utilized efficiently the OW substrate and generated electricity in the MFC setup reaching 0.05 mW/m 2 maximum power. COD removal was remarkable reaching 83.6 ± 0.1%, while qualitative and quantitative gas chromatography/mass spectrometry (GC/MS) analysis of the OW total petroleum and polycyclic aromatic hydrocarbons, and fatty acids revealed high degradation capacity. It was also determined that P. citronellolis 620C produced pyocyanin as electron shuttle in the anodic MFC chamber. To the authors’ best knowledge, this is the first study showing (phenazine-based) pyocyanin production from a species other than P. aeruginosa and, also, the first time that P. citronellolis 620C has been shown to produce electricity in a MFC. The production of pyocyanin, in combination with the formation of biofilm in the MFC anode, as observed with scanning electron microscopy (SEM) analysis, makes this P. citronellolis strain an attractive and promising candidate for wider MFC applications.
Yuta Nakayasu, Hiroto Nakano, Masaki Umetsu et al.
Energy Technology · 2024
Microbial fuel cells (MFCs) present a promising alternative to traditional activated sludge treatment for livestock wastewater, offering a carbon‐neutral, sustainable approach to wastewater management. Activated sludge treatment requires significant energy input for aeration and produces unpleasant odors. MFCs eliminate the need for energy‐intensive aeration, simultaneously generating energy during wastewater treatment. Platinum‐based electrodes commonly used in the cathode of MFCs pose a significant cost barrier, necessitating advancements in electrode materials for practical, large‐scale application. This study reports on the performance of a continuous methanogen biocathode MFC system engineered to simultaneously treat cattle‐barn wastewater and utilize carbon dioxide without 2‐bromoethanesulfonic acid (BES). Carbon felt treated with nitric acid without BES successfully reduces methane production by 93%. An MFC configuration utilizing nitric acid‐treated carbon felt as the anode and an oak‐derived carbon electrode as the cathode effectively treat wastewater and convert CO 2 to methane, yielding a power density of 5.5 mW m −2 and Coulombic efficiency of 7.3%, approximately twice those without nitric acid treatment and surpassing even the performance of the system with BES treatment. This system represents a promising, low‐cost, and environmentally sustainable approach to renewable energy production and livestock wastewater treatment.
Pei‐Zhi Yang
Heat Transfer—Asian Research · 2010
Abstract Three kinds of adsorption refrigeration cycles are analyzed in this paper, a two‐bed continuous cycle, an adiabatic mass recovery cycle, and an isothermal mass recovery cycle. Operating parameters (including desorption temperature, adsorption temperature, cycle adsorption rate, COP, and period refrigerating capacity) with the change of the evaporating temperature, condensing temperature, heat capacity ratio, and heat resource temperature are discussed. The analysis indicates that performance differences between the mass recovery cycle and the two‐bed continuous cycle are reduced with an increasing of evaporating temperature and heat source temperature. By increasing the heat capacity ratio, COP values for the three kinds of cycle decrease. When the heat source temperature is between 70 and 90°C, the performance of the isothermal mass recovery cycle is best. Through study, this paper puts forward that the isothermal mass recovery cycle is the best cycle for adsorption refrigeration systems driven by fuel cell electrical vehicle waste heat. © 2010 Wiley Periodicals, Inc. Heat Trans Asian Res, 39(7): 523–538, 2010; Published online 16 July 2010 in Wiley Online Library ( wileyonlinelibrary.com ). DOI 10.1002/htj.20315
Lanka Tata Rao, Satish Kumar Dubey, Arshad Javed et al.
Energy Technology · 2022
Paper devices are cutting‐edge platforms for creating miniaturized energy conversion, storage, and sensing devices. In such devices, co‐laminar flow and embedded capillaries not only eliminate membranes and external pumps but also allow widespread application. The fabrication, optimization, and characterization of a microfluidic paper ethanol fuel cell (MPEFC) has been demonstrated in the presented study. The MPEFC uses ethanol and sodium hydroxide as fuel and sulfuric acid as electrolytes. Numerous experiments have been conducted to improve the performance of MPEFC by optimizing various electrode types such as laser‐induced graphene (LIG), Ag nano‐ink/LIG, buckypaper, Ag nano‐ink/buckypaper, and two different 3D printed conductive electrodes. Different electrolyte concentrations (NaOH‐0.25, 0.5, 1 m ) have been studied to understand the impact on ion conductivity. It is observed that the developed MPEFC with multiwalled carbon nanotube ‐buckypaper as an optimized electrode, 1 M ethanol with 0.5 m NaOH as anolyte, and 1 m H 2 SO 4 as electrolyte delivered the best performance with a current density of 1756.2 μA cm −2 , and power density of 72.62 μW cm −2 , at a stable open‐circuit voltage of 235 mV with Gr 1 cellulose microchannel with parallel stacked configuration. This work demonstrates the effective enhancement of the output power with inexpensive individual MPEFC.
M. H. Pishbin, A. R. Mohammadi, M. Nasri
Fuel Cells · 2007
Abstract The aim of this research is to optimise manufacturing parameters for a fuel cell electrode. The combination of nickel oxide, silver oxide and ammonium bicarbonate powders is used to produce the electrode. The main role of silver element is to increase the activity in the electrode. Ni–Ag electrode can be used in fuel cells as positive and negative electrodes. All powders are mixed in the benzene solution by a magnetic mixer and then compressed to form green electrode. The range of pressure in this step is between 40 and 160 MPa. The green electrode is sintered in hydrogen atmosphere through a tube furnace and then cooled to 200 °C under argon atmosphere. The range of sintering temperature and time is 500–800 °C and 10–60 min, respectively. Also, silver oxide and ammonium bicarbonate percentages are varied from 20 to 65 and 15 to 35%, respectively. All parameters including composition, pressure, sintering temperature and time are changed during electrode fabrication to achieve optimised properties in the electrode. So, it is necessary to perform several tests measuring porosity, surface area, density, weight loss, mechanical strength, shrinkage, exchange current density and metallographic photos. The optimum conditions of the electrode production resulting from this investigation include compacting pressure 60 MPa, sintering temperature 560 °C, sintering time 15 min, silver oxide percentage 50% and ammonium bicarbonate percentage 27%.
Iwona Gajda, John Greenman, Carlo Santoro et al.
Journal of Chemical Technology & Biotechnology · 2018
Abstract BACKGROUND In this work, a small‐scale ceramic microbial fuel cell (MFC) with a novel type of metal–carbon‐derived electrocatalyst containing iron and nicarbazin (Fe‐NCB) was developed, to enhance electricity generation from neat human urine. Substrate oxidation at the anode provides energy for the separation of ions and recovery from urine without any chemical or external power additions. RESULTS The catalyst was shown to be effective in clear electrolyte synthesis of high pH, compared with a range of carbon‐based metal‐free materials. Polarisation curves of tested MFCs showed up to 53% improvement (44.8 W m −3 ) in performance with the use of Fe‐NCB catalyst. Catholyte production rate and pH directly increased with power performance while the conductivity decreased showing visually clear extracted liquid in the best‐performing MFCs. CONCLUSIONS Iron based catalyst Fe‐NCB was shown to be a suitable electrocatalyst for the air‐breathing cathode, improving power production from urine‐fed MFCs. The results suggest electrochemical treatment through electro‐osmotic drag while the electricity is produced and not consumed. Electro‐osmotic production of clear catholyte is shown to extract water from urine against osmotic pressure. Recovering valuable resources from urine would help to transform energy intensive treatments to resource production, and will create opportunities for new technology development. © 2018 The Authors. Journal of Chemical Technology & Biotechnology published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.
Abdul Azeez Olayiwola Sirajudeen, Mohamad Suffian Mohamad Annuar, Ramesh Subramaniam
Biotechnology and Applied Biochemistry · 2020
Abstract A microbial fuel cell is a sustainable and environmental‐friendly device that combines electricity generation and wastewater treatment through metabolic activities of microorganisms. However, low power output from inadequate electron transfer to the anode electrode hampers its practical implementation. Nanocomposites of oxidized carbon nanotubes and medium‐chain‐length polyhydroxyalkanoates (mcl‐PHA) grafted with methyl acrylate monomers enhance the electrochemical function of electrodes in microbial fuel cell. Extensive polymerization of methyl acrylate monomers within mcl‐PHA matrix, and homogenous dispersion of carbon nanotubes within the graft matrix are responsible for the enhancement. Modified electrodes exhibit high conductivities, better redox peak and reduction of cell internal resistance up to 76%. A stable voltage output at almost 700 mV running for 225 H generates maximum power and current density of 351 mW/m 2 and 765 mA/m 2 , respectively. Superior biofilm growth on modified surface is responsible for improved electron transfer to the anode hence stable and elevated power output generation.
Muaz Mohd Zaini Makhtar, Husnul Azan Tajarudin, Mohd Dinie Muhaimin Samsudin et al.
AIP Advances · 2021
Dewatered sludge is redundantly found in a municipal wastewater treatment plant, and the amount is increasing every year. However, the dewatered sludge could be used to power the membrane-less microbial fuel cell (ML-MFC), which is operated electrochemically via incorporation of electricity producing micro-organisms. The dewatered sludge normally acts as an electron donating substrate. Results showed that the ML-MFC produced voltage at about 927.7 ± 11.24 mV whereby 178.7 mg/L of chemical oxygen demand (COD) was removed after 240 h of incubation period. Nonetheless, voltage and COD removal values obtained from the dewatered sludge in the ML-MFC might differ every time the study is repeated because the availability of maximum biomass of electrogenic bacteria (EB) will be different due to the heterogeneous properties and EB performance inside the ML-MFC. The parametric uncertainty analysis of COD removal was then assessed using Monte Carlo simulation (stochastic variable) to determine the distribution probability affected by the fluctuation and variation of kinetic model parameters. From the study of 100 000 samples tested (simulation), the results show that the substrate removal (S) value ranged from 172.58 to 185.02 mg/L. The impact of each kinetic parameter on the ML-MFC performance was evaluated via sensitivity analysis. It is found that the ML-MFC performance significantly relied on the growth of EB present.
Mohammad Amin Sadeghi, Jake Barralet, Tomislav Friscic et al.
ECS Meeting Abstracts · 2019
Polymer electrolyte fuel cells (PEFCs) have attracted special attention as a source of power for vehicles and stationary power generation systems, owing to features such as high energy density and fast refueling times. They are, however, still expensive and therefore their successful commercialization is contingent on continued reduction in their price. During the last decade according to U.S. Department of Energy, the cost power generated by fuel cell (FC) systems has been reduced from $124/kW in 2006 to $53/kW in 2015, with the ultimate goal set at $30/kW. Apart from reducing the manufacturing and material processing costs, maximizing their catalytic performance directly translates into cheaper FCs. This can be done in two ways: (1) coming up with new catalysts that are either cheaper or more durable (or both) than platinum, and (2) reducing the platinum loading without affecting performance. Here, we consider the latter by optimizing – via computer simulation – the internal structure of the PEFC catalyst layer (CL), which is host to platinum nanoparticles deposited on a carbon backbone for electron transport and a thin coating of an ionomer (e.g. Nafion) for ion transport. Optimizing the internal structure, by definition, requires that a pore-scale modeling strategy to be employed rather than volume-averaged continuum methods. This challenge has two parts: (1) digital reconstruction of the CL with high fidelity such that it is representative of an actual CL, and (2) multiphysics simulation of coupled nonlinear equations associated with different transport mechanisms in different locations, i.e. electron transport in the solid phase, ion transport in the ionomer phase, and gas (oxygen) transport in the void phase together coupled with interfacial phenomena such as gas partitioning and electrochemical reaction at void-ionomer and ionomer-platinum interfaces, respectively. The length scales at which different transport mechanisms occur vary from only a few nanometers through the ionomer film up to a few tenths of a micron in inter-agglomerate pores. Such disparate length scales make it difficult to perform – in reasonable time – direct numerical simulation (DNS) on a large-enough section of the entire CL such that it is statistically representative. We propose pore-scale strategy based on a hybrid of DNS and pore network modeling (PNM). PNM is a pore-scale modeling technique in which a porous domain is mapped onto an equivalent graph such that each node represents a single pore. Such simplification reduces the computational complexity of PNMs up to 4-5 orders of magnitude, compared to an equivalent DNS. In this work, the void and the carbon backbone are each modeled by PNM, and the ionomer thin film and platinum nanoparticles are modeled by DNS. Briefly, the justification behind this decision is that transport of oxygen and protons, for the most part, are restricted by the diffusivity and ionic conductivity in the ionomer phase rather than in the void and carbon, respectively. For the digital reconstruction of the CL, we use “process-based” reconstruction in which the actual manufacturing process of the CL is mimicked. The reconstructed geometry is in the form of a three-dimensional (3D) image and consists of 4 distinct phases: carbon support, platinum, Nafion (as the ionomer), and void. Using a network extraction algorithm, the equivalent networks corresponding to the void and carbon phases are extracted. The entire digital reconstruction was performed using the open-source software OpenPNM and PoreSpy . We propose a simple algorithm to couple the two extracted networks with the remainder of the original 3D image, which now only consists of Nafion and platinum. Note that the computational bottleneck of the entire simulation is the DNS, which is only applied to the Nafion and platinum phases. Since the carbon backbone and the void usually contribute up to 80% of the total volume of the CL, the proposed hybrid scheme significantly reduces the computational time compared with the case where the entire domain is modeled using DNS. While the proposed hybrid model allows for simulating much larger sections of the CL – therefore obtaining more representative results – the DNS step still imposes a serious limitation. Ideally, one could apply PNM to model the Nafion film, eliminating the DNS step altogether. However, since the thickness of the Nafion film is very small compared to the largest length scale of the system, network extraction algorithms require ultrahigh-resolution 3D images to generate a reasonably-accurate network that represents the thin Nafion film. Therefore, this study can be regarded as the first step toward developing a full network model of the CL. We hope that this study will become a cornerstone for many future studies.
Fatima Zahra Belhaj, Hassan El Fadil, Zakariae El Idrissi et al.
Electronics · 2020
Based on full and rigorous study, this paper addresses the issue of ensuring a feasible association in practice between a Proton Exchange Membrane Fuel Cell (PEMFC) and DC-DC power converters including a buck and boost converter. This association is mathematically modeled, analyzed, and controlled by an optimal PID controller. Using absolute stability tools with a rigorous analytical approach that takes into consideration windup effects, in addition to the nonlinear behavior of the Proton Exchange Membrane Fuel Cell, sufficient conditions are provided to ensure that the closed-loop system is L2-stable. These conditions allow the optimal PID controller parameters to be chosen and ensure the closed-loop system stability, by tracking reference outputs, and an optimal performance against perturbations. Formal analysis, numerical simulations, and experimental validation were carried out to verify that the PID controller designed with an anti-windup action is robust and meets all of the pre-defined objectives. Moreover, this study demonstrates that the association between the PEMFC and the DC-DC converters is achieved if only certain conditions are met.
Eric Alexander Chadwick, Pranay Shrestha, Harsharaj Birendrasingh Parmar et al.
ECS Meeting Abstracts · 2024
The bipolar plate of polymer electrolyte membrane (PEM) fuel cells is responsible for reactant delivery, liquid product water removal, and mechanical stability of PEM fuel cell stacks. Bipolar plates account for 70-90% of the weight and volume and 18-28% of the production costof stacks [1]. Improving the function of the flow fields embedded in the bipolar plates can significantly impact the energy density of PEM fuel cells by improving liquid water management and reactant distribution. Researchers have modified conventional flow fields by adding baffles or partially narrowed channels as semi-obstructive structures in the channels, exploiting Forchheimer’s intertial effect to locally increase gas velocity, thereby increasing oxygen diffusion and water removal in the GDL [2,3]. However, adding obstructions such as baffles or narrowed channels inherently increases the overall pressure drop across the flow fields, thus increasing the power required to supply reactant gases. In other attempts, biomimetic channel architectures have been shown to enhance preferential water flow; however, these designs have not been tailored to control water accumulation for improved reactant distribution [4,5]. Therefore, there is still a need to investigate flow field land-channel architectures that both enhanced inertial gas diffusion to the catalyst layer reaction sites and efficiently remove excess liquid water. In this work, PEM fuel cell flow fields were laser-cut to enhance the liquid water removal and reactant distribution in the under-land region of the GDL. Operando synchrotron X-ray radiography revealed reduced GDL water accumulation when using our novel flow fields. The reduced mass transport overpotential and corresponding power density increase were attributed to enhanced liquid water removal and reactant distribution due to the flow field design. Ultimately, this work can be used to further optimize the design of bipolar plates for more efficient stacks and accelerate the commercialization of PEM fuel cells. References: Y. Wang, D. F. Ruiz Diaz, K. S. Chen, Z. Wang, and X. C. Adroher, Materials Today , 32 , 178–203 (2020). H. Guo, H. Chen, F. Ye, and C. F. Ma, Int J Energy Res , 43 , 2737–2755 (2019). H. Chen, H. Guo, F. Ye, and C. F. Ma, Int J Hydrogen Energy , 46 , 2990–3007 (2021). N. Guo, M. C. Leu, and U. O. Koylu, Int J Hydrogen Energy , 39 , 21185–21195 (2014). S. Feng et al., Science , 373 , 1344–1348 (2021).
Yuxian Yang, Jialuo Lin, Xin Li et al.
Physical Chemistry Chemical Physics · 2022
The cathode electrocatalyst Nano-Co@NC is synthesized from ZIF-67, exhibiting a high Co mass loading and enabling MFCs with a comparable initial power density to and better durability than that using Pt/C.
Chuan Yu Yen, Shu Hang Liao, Yu Feng Lin et al.
Key Engineering Materials · 2007
The thin polymer composite bipolar plates (the thickness < 1.5 mm) for use in polymer electrolyte membrane fuel cells (PEMFCs) containing vinyl ester resin, graphite powder, organoclay have been fabricated by bulk molding compound (BMC) process. Organoclay prepared by ionic exchange of montmorillonite (MMT) with three different Mw of diamine intercalating agents was used to reinforce the mechanical properties of the composite bipolar plates. Results indicate that the basal spacing and content of MMT varied with Mw of POP-diamines are critical in determining the resultant mechanical properties for bipolar plates. The flexural strength and the unnotched impact strength of the plate were ca. 38 % (from 30.21 MPa to 45.66 MPa) and ca. 30 % (from 58.11 J/m to 80.21 J/m) higher than the pristine graphite plate, respectively, as the basal spacing of MMT (2 phr) was increased from 1.71 to 5.43 nm. The limiting oxygen index (L.O.I.) and the UL-94 test revealed that the bipolar plate possesses excellent flame retardant with L.O.I. higher than 50 and UL-94-V0. In addition, the electrical conductivity of the bipolar plates with different MMT contents and basal spacing of MMT is higher than 100 S/cm.
Gustavo A. Andreasen, Silvina G. Ramos, Hernán A. Peretti et al.
Journal of Electrochemical Energy Conversion and Storage · 2016
The performance of a hydrogen storage prototype loaded with AB5H6 hydride, whose equilibrium pressure makes it suitable for both feeding a H2/air proton exchange membrane (PEM) fuel cell and being charged directly from a low-pressure water electrolyzer, interacting thermally with the fuel cell exhaust air, is reported. The nominal 70 L hydrogen storage capacity of the prototype suffices for hydrogen delivery at 0.5 L min−1, which allows a power supply of 50 W for 140 min from the H2/air fuel cell in the absence of thermal interaction. The storage prototype was characterized by monitoring the internal pressure and the temperatures of the external wall and at the center inside the container at different hydrogen discharge conditions. The responses of the integrated system after either immersing the metal hydride container in air or exposing it to the fuel cell hot exhaust air stream under forced convection were compared. The system shows the best performance when the heat generated at the fuel cell is used to increase the metal hydride container temperature, allowing the operation of the fuel cell at 280 W for 16 min at a high hydrogen flow rate of 4 L min−1.
Ahmet Erensoy, Nurettin Çek
ChemistrySelect · 2018
Abstract In this study, biofuel properties of poplar wood materials rich in organic materials were investigated for microbial fuel cells. Therefore, in this study, investigates the chemical, biochemical properties with electrochemical performance of single chamber microbial fuel cell manufactured using poplar biomass materials, natural soil, graphite anode electrode and graphite cathode electrode. With the increase in the weight of the poplar tree in the microbial fuel cells, the power density increased. SEM, EDS, FTIR analyses showed that bacillus and coccus type bacteria in the natural structure of the soil act as the catalyst in the anode electrode. Poplar wood, electrodes and bacteria have served in harmony. According to experimental results, the maximum power reaches to 16.88 mW and microbial fuel cell successfully displays a maximum power density of 8555 mW/m 2 . All these results indicate that poplar wood may be appropriate biofuel sources for electrical energy generation as an effective environmentally microbial fuel cell technology.
Giuseppe De Lorenzo, Francesco Piraino, Francesco Longo et al.
Energies · 2022
This paper describes the implementation of a hydrogen-based system for an autonomous surface vehicle in an effort to reduce environmental impact and increase driving range. In a suitable computational environment, the dynamic electrical model of the entire hybrid powertrain, consisting of a proton exchange membrane fuel cell, a hydrogen metal hydride storage system, a lithium battery, two brushless DC motors, and two control subsystems, is implemented. The developed calculation tool is used to perform the dynamic analysis of the hybrid propulsion system during four different operating journeys, investigating the performance achieved to examine the obtained performance, determine the feasibility of the work runs and highlight the critical points. During the trips, the engine shows fluctuating performance trends while the energy consumption reaches 1087 Wh for the fuel cell (corresponding to 71 g of hydrogen) and 370 Wh for the battery, consuming almost all the energy stored on board.
Radwan A. Almasri, Nasser AM Barakat, Osama M Irfan
Journal of Chemical Technology & Biotechnology · 2024
Abstract Background Recently, the concept of the membrane‐less microbial fuel cell (MFC) has gained traction to avoid the high internal resistance that is created upon utilizing conventional membranes. Nevertheless, an overlooked problem arises from the ingress of oxygen from the cathode side into the anolyte solution, fostering the formation of biofilms by aerobic microorganisms on the cathode surface. This biofilm layer poses a formidable impediment, leading to cell disconnection. Moreover, low surface area of conventional anodes is another important issue behind the low power density generation. In this research, a novel approach to circumvent biofilm formation and achieve stable and high‐power‐density output from MFCs by harnessing a commercial antibacterial spacer is introduced. Results Air‐cathode, sewage‐driven MFCs showed continuous power generation without the need for external microorganisms. Conversely, the absence of the innovative membrane resulted in a catastrophic power breakdown after 125 h of operation due to the formation of a dense biofilm layer on the cathode. Through the utilization of the proposed membrane strategy, stable power density output of 100 ± 8, 135 ± 11 and 142 ± 10 mW m −2 with carbon cloth, carbon paper and carbon felt anodes, respectively, was achieved. Moreover, a novel anode is introduced from graphitization of grape tree branches. The proposed anode could increase the generated power to 516 ± 17 mW m −2 from the sewage‐driven air‐cathode MFC, more than three times compared to the best conventional anode, carbon felt. Conclusion This study provides significant solutions for sustainability, low‐performance and high‐cost problems of microbial fuel cells. © 2024 Society of Chemical Industry (SCI).
Jaydev Chetan Zaveri, Shankar Raman Dhanushkodi, C. Ramesh Kumar et al.
Energies · 2023
Modern industries encourages the use of hydrogen as an energy carrier to decarbonize the electricity grid, Polymeric Electrolyte membrane fuel cell which uses hydrogen as a fuel to produce electricity, is an efficient and reliable ‘power to gas’ technology. However, a key issue obstructing the advancement of PEMFCs is the unpredictability of their performance and failure events caused by flooding and dehydration. The accurate prediction of these two events is required to avoid any catastrophic failure in the cell. A typical approach used to predict failure modes relies on modeling failure-induced performance losses and monitoring the voltage of a cell. Data-driven machine learning models must be developed to address these challenges. Herein, we present a machine learning model for the prediction of the failure modes of operating cells. The model predicted the relative humidity of a cell by considering the cell voltage and current density as the input parameters. Advanced regression techniques, such as support vector machine, decision tree regression, random forest regression and artificial neural network, were used to improve the predictions. Features related to the model were derived from cell polarization data. The model’s results were validated with real-time test data obtained from the cell. The statistical machine learning models accurately provided information on the flooding- and dehydration-induced failure events.