Yuji Okuyama, Tomohiro Kuroha, Yamauchi Kosuke et al.

ECS Meeting Abstracts • 2020

Barium zirconate have high chemical stability with CO 2 comparison with barium cerate. Acceptor doped barium zirconate show high proton conductivity [1]. The proton conductivity of yttrium doped barium zirconate is 1×10 -2 Scm -1 at 600 ℃ and it is attracted as the electrolyte of fuel cell and water vapor electrolysis cell. The fuel cell using proton conducting oxide was called to PCFC (proton ceramic fuel cell) and work at the intermediate temperature. PCFC is expected to be the energy conversion device in future because of high efficiency [2] and low production cost [3]. Generally, nickel is used as anode of PCFC. The anode overpotential of nickel is lower than that of the other metals. However, the nickels dissolve to the proton conducting oxide and possibly increase the ohmic resistance of electrolyte. Moreover, the nickel and the electrolyte possibly form the blocking layer such as the complex oxide. Although the proton conductivity of yttrium doped barium zirconate is highest in the zirconate-type proton conductor, BaY 2 NiO 5 is formed between the nickel and the yttrium doped barium zirconate [4] and it might work as the blocking layer of proton. In this study, the reaction product between NiO and BaZr 0.8 M 0.2 O 3-δ ( M =Sc, In, Yb, Y, Gd) were confirmed by X-ray diffraction analysis. In order to clarify the NiO dissolution effect on the proton transport properties of BaZr 0.8 M 0.2 O 3-δ ( M =Sc, In, Lu, Yb, Y), the partial conductivity of the proton and the hole for BaZr 0.8 M 0.2 O 3-δ ( M =Sc, In, Lu, Yb, Y) with NiO were measured at temperature range of 200-600 ℃ by impedance analysis. The current efficiency on the polarization properties, then was examined for the fuel cell system using Acceptor-doped barium zirconate with NiO as electrolyte. Moreover, we investigated the effect of dopants on the ease of cell fabrication. The conventional ceramic tape-casting and firing process for fabricating laminated ceramic electronic devices was used, which is important for practical use. The power generation performance of planer cells fabricated by this process was also measured. The X-ray diffraction patterns of 0.4 mol% NiO doped BaZr 0.8 M 0.2 O 3-δ ( M = Sc, In, Yb, Y, Gd) were measured for the the samples as-sintered and annealed under 1%H 2 at 873K. The peak of the NiO or Ni phase except the barium zircanate phase was observed for 0.4 mol% NiO doped BaZr 0.8 M 0.2 O 3-δ ( M = Sc, In, Yb). On the other hand, the Ba M 2 NiO 5 phase was observed for M =Y, Gd. When the ionic radius of dopant is in excess of the size of Yb, the Ba M 2 NiO 5 was formed as the reaction product between NiO and BaZr 0.8 M 0.2 O 3-δ . The proton conductivity of the series of BaZr 0.8 M 0.2 O 3-δ containing no NiO increased in the order of In<Sc<Lu<Yb<Y. On the other hand, there was no distinct difference of the hole conductivity for dopant. PCFC using BZ M 20 ( M =Lu, Yb, Tm, Y) has an energy efficiency of more than 0.8 at 873 K. The proton conductivity decreased and the hole conductivity did not change for all series of BaZr 0.8 M 0.2 O 3-δ due to NiO dissolution in BaZr 0.8 M 0.2 O 3-δ . Therefore, proton transport number and the efficiency of the fuel cell decrease by addition to NiO. Considering the above, the ytterbium-doped barium zirconate did not form a complex oxide with NiO and might have high proton conductivity. The performance of PCFC using BZYb20 as electrolyte was measured. The maximum power density values at 600 and 700 °C were 0.50 and 0.70 Wcm −2 for the planar cells using BZYb20, respectively. Electrochemical impedance spectroscopy of the cell showed that the ohmic resistance was 0.28 Ωcm 2 at 600 °C, which was approximately three times larger than the resistance value calculated using the bulk conductivity of BZYb20 and the electrolyte thickness and was in agreement with the resistance value of BZYb20 with NiO. [1] K.D. Kreuer et al., Solid State Ionics 145(2001)295-306. [2] Y. Matsuzaki et al., Scientific Reports, 5:12640(2015)1-10. [3] A. Doubois et al., ECS Transaction 78(1) (2017)1963-1972. [4] J. Tong et al., J. Mater. Chem. , 20(2010)6333.

Wenqin Jiang, Jian Zhang, Qiulin Yang et al.

Sustainability • 2024

The Anammox anaerobic fluidized bed microbial fuel cell (Anammox AFB-MFC) exhibits exceptional performance in both nitrogen removal and electricity generation, effectively eliminating ammonia nitrogen (NH4+-N) and nitrite nitrogen (NO2−-N) pollutants. This technology offers the advantages of high efficiency in nitrogen removal and low electricity consumption. By coupling an AFB with an MFC, the Anammox AFB-MFC was developed through the introduction of anaerobic ammonia-oxidizing bacteria (AnAOB) into MFC. Anammox AFB-MFC’s nitrogen removal ability was found to be superior at an influent COD concentration of 200 mg/L, as determined by a study conducted under unchanged conditions. Subsequently, an open and closed-circuit experiment was performed on the Anammox AFB-MFC system while maintaining a COD concentration of 200 mg/L in the influent. Remarkably, the reactor exhibited significantly enhanced nitrogen removal performance when electricity generation occurred. Throughout the entire experimental process, the reactor consistently maintained high nitrogen removal efficiency and electricity production performance. Under optimal experimental conditions, the reactor achieved a remarkable nitrogen removal rate of 91.8% and an impressive output voltage of 439.1 mV. Additionally, the generation of Anammox bioparticles in MFC significantly contributed to efficient pollutant removal. This study elucidates the impact of organic matter on both the nitrogen removal and electricity generation capabilities of Anammox AFB-MFC, as well as highlights the synergistic effect between MFC electricity generation and nitrogen removal in the reactor.

Pengcheng Zhu, Shumin Zhuo, Weiying Zhang et al.

Journal of Applied Polymer Science • 2023

Abstract Microbial fuel cells (MFCs) are a potential biotechnology for simultaneous degradation of organic wastewater and power generation. In this paper, a biocompatible composite is constructed around a copper mesh with sodium alginate/agar and activated carbon (CM‐SA/AC) and acts as an efficient anode for MFCs after being microbe immobilized. The power performance of the MFC with CM‐SA/AC anode is investigated. The results show that the addition of activated carbon is conducive to the immobilization of bacteria on CM‐SA/AC anode and fast start‐up of MFCs. The power density reaches 1088.6 mW/m 2 , which is 2.03 times and 1.75 times that of CM‐SA (without activated carbon) anode and carbon felt anode, respectively. In case of a candied wastewater treatment, the MFC with immobilized CM‐SA/AC anode exhibits a much higher power density (724.5 mW/m 2 ) than that with carbon felt anode (145.0 mW/m 2 ), together with a longer stabilization time and a smaller charge‐transfer resistance. The total removal rate of chemical oxygen demand (COD) reaches 79.4 ± 0.65%. The present study will facilitate the development of inexpensive and biocompatible anodes to facilitate the application of MFCs in wastewater treatment.

Robyn Barbato, Robert Jones, Michael Musty et al.

• 2025

Electrogenic bacteria produce power in soil based terrestrial microbial fuel cells (tMFCs) by growing on electrodes and transferring electrons released from the breakdown of substrates. The direction and magnitude of voltage production is hypothesized to be dependent on the available substrates. A sensor technology was developed for compounds indicative of anthropological activity by exposing tMFCs to gasoline, petroleum, 2,4-dinitrotoluene, fertilizer, and urea. A machine learning classifier was trained to identify compounds based on the voltage patterns. After 5 to 10 days, the mean voltage stabilized (+/- 0.5 mV). After the entire incubation, voltage ranged from -59.1 mV to 631.8 mV, with the tMFCs containing urea and gasoline producing the highest (624 mV) and lowest (-9 mV) average voltage, respectively. The machine learning algorithm effectively discerned between gasoline, urea, and fertilizer with greater than 94% accuracy, demonstrating that this technology could be successfully operated as an environmental sensor for change detection.

Jakub Drewnowski, Francisco Fernandez-Morales

Sustainability • 2016

Nowadays, pollution caused by energy production systems is a major environmental concern. Therefore, the development of sustainable energy sources is required. Amongst others, the microbial fuel cell (MFC) seems to be a possible solution because it can produce clean energy at the same time that waste is stabilized. Unfortunately, mainly due to industrial discharges, the wastes could contain nitrates, or nitrates precursors such ammonia, which could lead to lower performance in terms of electricity production. In this work, the feasibility of coupling anodic denitrification process with electricity production in MFC and the effect of the nitrates over the MFC performance were studied. During the experiments, it was observed that the culture developed in the anodic chamber of the MFC presented a significant amount of denitrificative microorganisms. The MFC developed was able to denitrify up to 4 ppm, without affecting the current density exerted, of about 1 mA/cm2. Regarding the denitrification process, it must be highlighted that the maximum denitrification rate achieved with the culture was about 60 mg·NO3−·L−1·h−1. Based on these results, it can be stated that it is possible to remove nitrates and to produce energy, without negatively affecting the electrical performance, when the nitrate concentration is low.

Irene Bavasso, Luca Di Palma, Debora Puglia et al.

Polymer Engineering & Science • 2019

Nanocomposite membranes based on polyethersulfone (PES) and nanomagnetite have been investigated with regards to the effect of pretreatments on the electrochemical performance of microbial fuel cells (MFCs). Nanocomposite membranes containing various amounts of Fe 3 O 4 (5, 10, and 20 wt%) were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, thermogravimetric analysis, differential scanning calorimetry, and tensile tests. The application in MFC systems requires also chemical characterizations such as ion exchange capacity, water uptake, and oxygen permeability. The best formulation (PES10) showed electrochemical properties similar to the PES20. With the aim of obtaining a high‐performance membrane with a low filler dosage, a pretreatment procedure (1 h of boiling step in deionized water and 1 h of immersion in 0.5 M of H 2 SO 4 ) was adopted. The results of such pretreatment in terms of maximum power and current density were 10.59 ± 0.72 mW/m 2 and 52.07 ± 0.86 mA/m 2 , respectively. The adoption of a pretreatment avoids the need of higher amount of nanofillers that can affect membrane surface roughness and its processing. Overall, the nanocomposite membranes represent a suitable technology in the MFC process. POLYM. ENG. SCI., 60: 371–379, 2019. © 2019 Society of Plastics Engineers

Cheng Li, Hong Liu

ECS Meeting Abstracts • 2018

Mixed species biofilms have been able to generate current densities of over 20 A/m 2 in microbial fuel cells (MFCs), while also offering advantages in stability, substrate flexibility, and culture maintenance costs. To further increase the current density, a possible approach is to enhance the conductivity of biofilms and thereby the direct extracellular electron transfer within the biofilms and to the anode. While examination of conductivity in microbial samples is still in its relative infancy and conceptual models in terms of conductive mechanisms are still being developed and debated, our study has demonstrated that current-producing mixed species biofilms can exhibit high conductivity across non-conductive gaps. Differential responses observed over varying potentials also suggest that a redox driven conductivity mechanism is dominant in the tested mixed-species biofilms. Considering that some redox conductive organic polymer films possess negative magnetoresistance property (resistivity of a conductive material decreases as the magnetic field strength increases) and magnetic field may stimulate enzyme activity in certain anaerobic wastewater treatment systems, our mixed species biofilms were exposed to low intensity magnetic field to investigate the conductivity change and performance enhancement. Exposure of the biofilms to magnetic field has led to an over 100% increase in biofilm conductance and over 300% increase in current density. Application of the low intensity magnetic field also encouraged the enrichment of Geobacter spp. in biofilms. Short term application of magnetic field also increased the conductivity of anodic biofilms, resembling the negative magnetoresistivity that has not been observed in conductive biofilms before. These results not only enhance our understanding of the electrical conductivity in microbial aggregates, but also inform rational design and operation of microbial-based fuel cells.

Shiladitya Mukherjee, J. Vernon Cole, Kunal Jain et al.

ASME 2009 7th International Conference on Fuel Cell Science, Engineering and Technology • 2008

In Proton Exchange Membrane Fuel Cells (PEMFCs), water management and the effective transport of water through the gas-diffusion-layer (GDL) are key issues for improved performance at high power density and for durability during freeze-thaw cycles. The diffusion layer is a thin (∼150–350μm), porous material typically composed of a web of carbon fibers and particles, and is usually coated with hydrophobic Teflon to remove the excess water through capillary action. In-situ diagnostics of water movement and gas-reactant transport through this thin opaque substrate is challenging. Numerical analyses are typically based on simplified assumptions, such as Darcy’s Law and Leverett functions for the capillary pressure. The objective of this work is to develop a high fidelity CFD modeling and analysis tool to capture the details of multiphase transport through the porous GDL. The tool can be utilized to evaluate GDL material design concepts and optimize systems based on the interactions between cell design, materials, and operating conditions. The flow modeling is based on the Lattice Boltzmann Method (LBM). LBM is a powerful modeling tool to simulate multiphase flows. Its strength is in its kinetic theory based foundation, which provides a fundamental basis for incorporating intermolecular forces that lead to liquid-gas phase separation and capillary effects without resorting to expensive or ad-hoc interface reconstruction schemes. At the heart of the solution algorithm is a discrete form of the well-known Boltzmann Transport Equation (BTE) for molecular distribution, tailored to recover the continuum Navier-Stokes flow. The solution advances by a streaming and collision type algorithm, mimicking actual molecular physics, which makes it suitable for porous media involving complex boundaries. We developed a numerical scheme to reconstruct various porous GDL microstructures including Teflon loading. Single and multiphase LBM models are implemented to compute permeability. Predicted values are in good agreement with measured data. The present modeling approach resolves the GDL microstructures and captures the influence of fiber orientation on permeability and the influence of Teflon loading on the development of preferential flow paths through the GDL. These observations can potentially guide the development of novel GDL materials designed for efficient removal of water.

Cong Xu, Lorenz T. Biegler, Myung S. Jhon

AIChE Journal • 2006

Abstract An H 2 Polymer Electrolyte Membrane (PEM) Fuel Cell power generation system composed of three subsystems: fuel reforming, fuel cell stack, and post combustion is examined. The system is simulated and optimized with a fuel cell model integrated within the process flow sheet. A case study optimization of the entire power generation system is presented and the influence of heat integration on the optimization is demonstrated. Our objectives are to maximize the energy and system efficiencies as well as the system profit. Here, optimization formulations with heat integration are used to realize our objectives, which explore the synergy between optimization and heat integration. Our results showed that we can achieve an energy efficiency as high as 58.30% and a system efficiency as high as 28.35%. For comparison, we provide results obtained from sequential process optimization followed by heat integration. The gain from the synergy is mostly exemplified in the profit maximization study, where the profit increases by almost 27.15% in the best case. Finally, we obtain optimization results that include feed vaporization of water to steam as a comparison for the heat integration. These results demonstrate the importance of simultaneous optimal heat integration for fuel cell‐based processes. © 2006 American Institute of Chemical Engineers AIChE J, 2006

Vahid Rezaee, Arash Houshmand

Bulletin of the Polytechnic Institute of Iași. Electrical Engineering, Power Engineering, Electronics Section • 2022

Abstract In this study, the performance analysis of waste heat recovery systems in a power generation system consisting of 13000 Proton Exchange Membrane Fuel Cells (PEMFC) in a stack has been investigated. Organic Rankine Cycle (ORC) and Kalina Cycle System 11 (KCS11) as bottoming cycles to convert generated waste heat of stack into electricity were compared with each other in a defined hybrid system. The improvement of system with an exact energy and exergy analysis after utilizing the waste heat in the hybrid system has been analyzed. Results show that the energy efficiency of combined system using Organic Rankine Cycle and Kalina Cycle System 11 increase by about 5% and 1.75% respectively. In addition, exergy analysis results indicate that exergy efficiency of combined system using Organic Rankine Cycle and Kalina Cycle System 11 increases by about 4% and 1.5% respectively. The total exergy destruction rate obtained for the hybrid power systems is 235.5 kW when ORC is used and 329.7 kW when KCS11 is used respectively. Results show that in presented systems ORC has higher energy and exergy efficiencies than KCS11 but different used working fluids and equipment of systems must also be considered from an economical point of view.

Yifeng Zhang, Booki Min, Liping Huang et al.

Applied and Environmental Microbiology • 2009

ABSTRACT Electricity generation from wheat straw hydrolysate and the microbial ecology of electricity-producing microbial communities developed in two-chamber microbial fuel cells (MFCs) were investigated. The power density reached 123 mW/m 2 with an initial hydrolysate concentration of 1,000 mg chemical oxygen demand (COD)/liter, while coulombic efficiencies ranged from 37.1 to 15.5%, corresponding to the initial hydrolysate concentrations of 250 to 2,000 mg COD/liter. The suspended bacteria found were different from the bacteria immobilized in the biofilm, and they played different roles in electricity generation from the hydrolysate. The bacteria in the biofilm were consortia with sequences similar to those of Bacteroidetes (40% of sequences), Alphaproteobacteria (20%), Bacillus (20%), Deltaproteobacteria (10%), and Gammaproteobacteria (10%), while the suspended consortia were predominately Bacillus (22.2%). The results of this study can contribute to improving understanding of and optimizing electricity generation in microbial fuel cells.

Chetan Laddha

ADIPEC • 2023

Abstract Ammonia is a dense energy carrier with high energy density and established supply chain for transport, and storage of hydrogen. Ammonia is a common commodity used in the fertiliser and chemical sector and has a potential to become an affordable and sustainable energy carrier to meet growing demand for industrial decarbonisation. The transport of hydrogen over long distances require an efficient and cost competitive carrier. Potential options for hydrogen carrier are ammonia, liquid organic hydrogen carrier (LOHC), liquid hydrogen, compressed hydrogen, and methanol. This paper describes an innovative ceramics-based solid oxide fuel cell technology for conversion of ammonia into fossil fuel parity energy at a thermal efficiency of 85%. The technology is based on proton conducting ceramics (PCC) electrochemical pathway which eliminates NOx emissions by design and ammonia slippage by catalyst performance and reactor design. The technology has been developed over 7 years, between 2016 to 2022, and the ammonia utilisation capabilities has been proven through demonstrations conducted for O&G and industrial companies. The technology uses low-cost and widely available ceramics-based catalyst. The technology is particularly suited for industrial decarbonisation because of the ability to yield high efficiency and the ability to produce low-cost heat at 700C and hydrogen as byproducts.

Myong-Hwan Kim, Seung Eul Yoo, Youngmo Goo

ECS Meeting Abstracts • 2016

In generally, Bipolar plate is vital component of PEM fuel cells, which supplies fuel and oxidant to reactive sites, removes reaction products, collects produced current and provides mechanical support for the cells in the stack. At the present, the bipolar plate for fuel cell vehicle is metallic separators formed of metallic materials such as stainless steel. The existing bipolar plate includes a land(contacting) portion directly bonded to the gas diffusion layer(GDL) and a channel portion that serves as a supply passage of reaction gases and an exhaust passage of water between land portions. In the typical separator, the land portion and the channel portion are disposed in a longitudinal direction and a flow field area in which the channel portion is formed both have a longitudinal structure. Also, the land portion and the channel portion are distinctly separated from each other.However, in the case of a typical separator, this non-uniformity causes a concentration difference between the area that the channel portion contacts and the area that the land portion contacts among the whole area of the MEA where the electrochemical reaction occurs and the performance of fuel cell is decreased.In this paper, a porous separator with various structures for a fuel cell, which causes the high diffusion of reactant gases was studied for increasing the performance of fuel cell. Also, we conducted an analysis of the properties(contact resistance, corrosion etc.), machinability(uniformity of thickness, change of hole structure etc.) and performance according to hole and pitch structure.In conclusions, the porous separator with optimum structure shows the performance above 200mA/cm 2 at 0.6V in comparision with the typical separator. It is considered to be minimize concentration differences between area in a gas diffusion layer and achieve uniform electrochemical reaction and electricity generation over the whole reaction are, by improving the structure of a flow field in which reactant gases flow.

Lanka Tata Rao, Satish Kumar Dubey, Arshad Javed et al.

Journal of Electrochemical Energy Conversion and Storage • 2020

Abstract Paper-based membraneless microfluidic fuel cell (PMMFC) has emerged as an alternative to conventional fuel cells. Extraction of optimum energy yield from these PMMFCs requires selection and study of various design and operating parameters. In this context, this paper presents reliability analysis and robust design of PMMFC composed of air-breathing graphite electrodes using multiple concentrations of formic acid and sulfuric acid as fuel and electrolyte, respectively. Combinations of four different grades of pencils are employed to prepare the electrodes using various pencil strokes. PMMFC is analyzed for two different orientations—horizontal and vertical, and the maximum power outputs were recorded. In order to analyze the combined effects of different factors governing the performance of PMMFC, a statistical approach of full factorial design is utilized to perform analysis of mean (ANOM), analysis of variance (ANOVA), signal to noise ratio (SNR), and desirability study. The response equations in terms of coded values of the factors are also derived. Rigorous desirability study, with the optimized parameters, concludes that the best desirability values for the horizontal and vertical arrangements of PMMFC are 0.8842 and 0.92768, respectively. Overall, this study helps to develop reliable, robust, and efficient PMMFC for many realistic applications.

Abdelkader Hilmi, Timothy Geary, Adam Franco et al.

ECS Meeting Abstracts • 2023

Introduction The molten carbonate fuel cell (MCFC) has emerged as one of the promising alternatives for carbon capture from industrial and power generation CO 2 sources. MCFC technology is less energy-intensive compared to conventional amine scrubbing that requires a significant amount of energy (steam) for solvent regeneration process. MCFC has been commercially used for distributed power generation, however its use in carbon capture applications has been limited to development activities and a few demonstrations during the past decades. The electrochemical reactions taking place during cell operation involve the CO 2 transfer from cathode to anode in the form of carbonate ions resulting in a gas stream with high CO 2 concentration on the anode exhaust. Therefore, MCFC stack systems can be combined with conventional combustion-powered generators (coal and/or natural gas-based power plants) for simultaneous CO 2 separation, power and hydrogen generation. CO 2 capture applications will typically take in flue gas from industrial furnaces, coal and gas fired combined cycle plants as the cathode inlet gas stream having low CO 2 concentrations ranging from 4% to 10% by volume and high CO 2 utilization (>90%). These CO 2 -lean conditions may pose a challenge for attaining good mass-transfer performance and life stability, therefore innovative approaches are needed in terms of hardware design and cathode structure to achieve long-term stability. FCE has tested numerous single cells (250 cm 2 ) and technology stacks (30 kW) under carbon capture operating conditions (4-8% CO 2 in the cathode inlet as opposed to >12% in baseline MCFC systems) to understand impact of design parameters on performance, life, and to investigate design solutions for further enhancement. Figure 1 highlights the effect of cathode water content on CO 2 utilization. It appears that differences exist between the ideal and measured CO 2 utilizations, indicating that less CO 2 is transferring from the cathode to anode than expected. This CO 2 transference reduction becomes more pronounced with higher water concentration, suggesting that a species other than CO 3 2- ion, likely hydroxide (OH - ion), may be generated and transported through the electrolyte matrix. This paper will review the cathode material stability and electrochemical performance under long-term carbon-capture operation. The effect of parameters such as water content, gas composition, utilization, and electrolyte chemistry, as well as approaches to enhance the CO 2 capture efficiency and life, will be discussed. Figure 1

Samuel Simon Araya, Søren Juhl Andreasen, Søren Knudsen Kær

Journal of Fuel Cell Science and Technology • 2014

As fuel cells are increasingly commercialized for various applications, harmonized and industry-relevant test procedures are necessary to benchmark tests and to ensure comparability of stack performance results from different parties. This paper reports the results of parametric sensitivity tests performed based on test procedures proposed by a European project, StackTest. The sensitivity of a Nafion®-based low temperature PEMFC stack's performance to parametric changes was the main objective of the tests. Four crucial parameters for fuel cell operation were chosen; relative humidity (RH), temperature, pressure, and stoichiometry at varying current density. Furthermore, procedures for polarization curve recording were also tested both in ascending and descending current directions.

Takuya Tsujiguchi, Misaki Kojima, Takanori Iwakami et al.

ECS Transactions • 2013

A hyperbranched polymer was used as a catalyst stabilizer for use in a direct formic acid fuel cell, DFAFC, to obtain a high performance with a low catalyst loading. The catalyst ink was prepared by the mixing of Pd nanoparticles stabilized by a hyper branched polymer (H-Pd) and carbon black, which was then calcinated at 300 oC and 500 oC in flowing nitrogen to investigate the effect of the stabilizer residual on the catalytic activity for the formic acid oxidation. It was found that the catalytic activity of the H-Pd was 6 times higher than that of Pd black with a 500 oC calcination. In this condition, a cluster of Pd nanoparticles was observed. By using this catalyst as an anode catalyst of the DFAFC, a 6 times higher power density could be obtained compared to the case using Pd black.

Scott A Mauger, Min Wang, Samantha Medina et al.

ECS Meeting Abstracts • 2019

Industrial production of polymer electrolyte membrane fuel cell (PEMFC) electrodes will rely on continuous roll-to-roll (R2R) coating methods to meet the rates needed for mass production. 1–5 R2R production commonly uses solution coating methods to coat liquids onto a moving substrate at linear speeds over 100 m/min. 6 There are many coating methods, which have different coating physics and require different ink formulations. For PEMFC catalyst layers these differences may result in different morphologies and performance. As production of fuel cell vehicles and power systems increases there is a need to understand the process science of fuel cell manufacturing. Here we present the results of a study comparing fuel cell catalyst layers coated using two R2R coating methods: slot-die and gravure, shown in Figure 1. These two methods were selected because the physics of applying the liquid to the substrate is very different between the two cases. Also, they have different viscosity and wet-film thickness ranges, which may make one method better suited to certain materials or catalyst loadings. In slot die coating, the pre-metered liquid is fed through the cavity of a metal die and extruded onto the substrate, as shown in Figure 1a. In gravure coating, an engraved metal roller is used to transfer the liquid from a pan to the substrate (Figure 1b). In both of these methods the coated liquid film then consolidates into the final dry film. These methods are quite different than common lab-scale coating methods like ultrasonic spraying or hand painting where ink is repeatedly applied to the same area to build up the thickness of the catalyst layers. Pt/C catalysts layers were coated directly onto carbon-fiber gas diffusion media to create gas diffusion electrodes (GDEs), without the use of a decal transfer process. These GDEs were assembled into membrane electrode assemblies (MEAs) by hot pressing to Nafion membranes. In situ performance and other electrochemical diagnostics were used to determine the influence of coating method on catalyst layer electrochemical properties. Electron microscopy was utilized to understand the influence of coating method on electrode morphology and its influence on electrochemical properties. We also explored the influence of solvent ratio to understand the potential coupling between ink formulation and coating methodology. Through this work we demonstrate R2R-coated GDEs with performance equal to ultrasonic spray-coated GDEs and a 200x increase in production rate. This demonstrates that R2R coating methods are suitable for mass-production of high-performance fuel cells. It also lays a foundation for further process science studies. (1) Mauger, S. A.; Neyerlin, K. C.; Yang-Neyerlin, A. C.; More, K. L.; Ulsh, M. Gravure Coating for Roll-to-Roll Manufacturing of Proton-Exchange-Membrane Fuel Cell Catalyst Layer. J Electrochem Soc 2018 , 165 (11), F1012–F1018. https://doi.org/10.1149/2.0091813jes. (2) Bodner, M.; García, H. R.; Steenberg, T.; Terkelsen, C.; Alfaro, S. M.; Avcioglu, G. S.; Vassiliev, A.; Primdahl, S.; Hjuler, H. A. Enabling Industrial Production of Electrodes by Use of Slot-Die Coating for HT-PEM Fuel Cells. Int. J. Hydrog. Energy 2019 . https://doi.org/10.1016/j.ijhydene.2018.11.091. (3) Steenberg, T.; Hjuler, H. A.; Terkelsen, C.; Sánchez, M. T. R.; Cleemann, L. N.; Krebs, F. C. Roll-to-Roll Coated PBI Membranes for High Temperature PEM Fuel Cells. Energy Environ. Sci. 2012 , 5 (3), 6076–6080. https://doi.org/10.1039/c2ee02936g. (4) Ding, X.; Didari, S.; Fuller, T. F.; Harris, T. A. A New Fabrication Technique to Manufacture an MEA Using Direct Coating of Nafion® onto Catalyzed GDL. In 218th ECS Meeting ; ECS, 2010; pp 255–265. https://doi.org/10.1149/1.3484523. (5) Ding, X.; Didari, S.; Fuller, T. F.; Harris, T. A. L. Membrane Electrode Assembly Fabrication Process for Directly Coating Catalyzed Gas Diffusion Layers. J. Electrochem. Soc. 2012 , 159 (6), B746. https://doi.org/10.1149/2.103206jes. (6) Ding, X.; Liu, J.; Harris, T. A. L. A Review of the Operating Limits in Slot Die Coating Processes. AIChE J. 2016 , 62 (7), 2508–2524. https://doi.org/10.1002/aic.15268. Figure 1

Antonio Molinero, Juan Carlos Oller, José Miguel Barcala et al.

ECS Meeting Abstracts • 2022

An airship, or dirigible balloon, is an aircraft that gains its lift from a gas less dense than air, like helium. For traction, airships have two or more propellers normally attached to a gondola that is suspended under the balloon. At present, they are used for hovering long times without the need for a high speed, like for aerial observation, advertising, or as camera platforms. In our laboratory, the airship is being used as a platform for testing hydrogen fuel cell systems for aerial applications. The airship used in this communication is a 3 m 3 polyurethane's inflatable zeppelin, with radio control, and three electrical propellers (Fig. 1a). A hydrogen fuel cell system has been developed and integrated with the gondola for powering the propellers and electronics. The fuel cell is a 15 W PEMFC stack prototype able to work fully under passive feeding conditions (Fig. 1b). In addition, three supercapacitors have been implemented, that are recharged by the fuel cell, for eventual larger power demands up to 40 W. Hydrogen is stored in two metal hydride canisters with 2g capacity to provide 30 W h energy enough for a few hours autonomy. In addition, for fuel cell parameters monitoring, different sensors have been implemented that provide voltages of the individual cells, current, and temperatures. The sensors are connected to Arduino board, and measurements are continuously monitored by a Labview software with wifi. Boost dc-dc conversion provides 7V voltage power to feed the motors. The stack prototype allows for different testing configurations, using cells in series and parallel connection to change power characteristics with different voltage and current. Results of the testing are provided in this communication. Acknowledgement: The work is partially financed by the ELHYPORT project (PID2019−110896RB-I00), Spanish Ministry of Science and Innovation. Figure 1

, Thanaphorn Hakhen

• 2014

This research presents the application of model predictive control (MPC) to control a proton exchange membrane fuel cell (PEMFC). Firstly, the steady state analysis of PEMFC is considered to select its suitable operating conditions based on cell electrical characteristics. Then, the effect of input parameters on cell voltage and temperature is analyzed to investigate the dynamic behavior of PEMFC that is important for control design. It is found that the cell voltage and cell temperature depend on the inlet molar flow rates and temperature of hydrogen and air, and operating current density. To obtain an efficient control system, the control structure design of the PEMFC is considered to specify a good choice of the controlled and manipulated variables. An analysis of the steady-state relative gain array (RGA) is used for pairing of the controlled and manipulated variables. The result shows that the inlet molar flow rates of hydrogen and air are manipulated variables to regulate the cell temperature and partial pressure of hydrogen, respectively. Finally, a model predictive control (MPC) is developed and designed for controlling the cell temperature and partial pressure of hydrogen. Basically, MPC requires the process model used in its control algorithm. The PEMFC model is known to be complicated and involves uncertain parameters. Thus, an offline robust model predictive control (robust MPC) based on a linear time-varying (LTV) model is proposed for PEMFC control. The simulation results show that the robust MPC shows better control performance than conventional MPC because the robust MPC can guarantee robust stability.

H.‐P. Schmid, J. A. Wünning

Fuel Cells • 2004

Abstract Primary energy savings and CO 2 reduction is one of the key motivations for the use of fuel cell systems in the energy sector. A benchmark of domestic cogeneration by PEMFC with existing large scale power production systems such as combined steam‐gas turbine cycle, clearly reveals that only fuel cell systems optimising overall energy efficiency (> 85%) and electrical efficiencies (> 35%) show significant primary energy savings, about 10%, compared with the best competing technology. In this context, fuel processing technology plays a dominant role. A comparison of autothermal and steam reforming concepts in a PEMFC system shows inherent advantages in terms of efficiency at low complexity for the latter. The main reason for this is that steam reforming allows for the straightforward and effective use of the anode‐off gas energy in the reformer burner. Consequently, practical electrical system efficiencies over 40% seem to be achievable, most likely by steam reformers. FLOX®‐steam reforming technology has reached a high state of maturity, offering diverse advantages including: compact design, stable anode off‐gas usage, high efficiency, as well as simple control behaviour. Scaling of the concept is straightforward and offers an opportunity for efficient adaptation to smaller (1 kW) and larger (50 kW) units.

P Rama, R Chen, R Thring

Proceedings of the Institution of Mechanical Engineers, Part A: Journal of Power and Energy • 2005

A mathematical multi-species modelling framework for polymer electrolyte fuel cells (PEFCs) is presented on the basis of fundamental molecular theory. Characteristically, the resulting general transport equation describes transport in concentrated solutions and also explicitly accommodates for multi-species electro-osmotic drag. The multi-species nature of the general transport equation allows for cross-interactions to be considered, rather than relying upon the superimposition of Fick's law to account for the transport of any secondary species in the membrane region such as hydrogen. The presented general transport equation is also used to derive the key transport equations used by the historically prominent PEFC models. Thus, this work bridges the gap that exists between the different modelling philosophies for membrane transport in the literature. The general transport equation is then used in the electrode and membrane regions of the PEFC with available membrane properties from the literature to compare simulated one-dimensional water content curves, which are compared with published data under isobaric and isothermal operating conditions. Previous work is used to determine the composition of the humidified air and fuel supply streams in the gas channels. Finally, the general transport equation is used to simulate the crossover of hydrogen across the membrane for different membrane thicknesses and current densities. The results show that at 353 K, 1 atm, and 1 A/cm 2 , the nominal membrane thickness for less than 5 mA/cm 2 equivalent crossover current density is 30 μm. At 3 atm and 353 K, the nominal membrane thickness for the same equivalent crossover current density is about 150 μm and increases further to 175 μm at 383 K with the same pressure. Thin membranes exhibit consistently higher crossover at all practical current densities compared with thicker membranes. At least a 50 per cent decrease in crossover is chieved at all practical current densities, when the membrane thickness is doubled from 50 to 100 μm.

M. Muthukumar, P. Karthikeyan, V. Lakshminarayanan et al.

Applied Mechanics and Materials • 2014

The geometrical and flow parameters are governing the performance of the Proton Exchange Membrane Fuel Cell (PEMFC). The flow channels are used for distributing the reactants uniformly throughout the active area of fuel cell. Among different flow field designs, the serpentine flow field can give better performance to the PEM fuel cell. This paper numerically investigates the effects of the serpentine flow field with different number of passes. The 2 pass, 3 pass and 4 pass serpentine flow field designs of same rib size and channel size were modelled and analyzed using commercially available software package. From the polarization curves and performance curves drawn using the numerical results, the performance of three flow channel designs were compared and the maximum power densities of each design were found

Guruviah Velayutham, Srinivas Sribollepalli, P Kalingamuthu

ECS Meeting Abstracts • 2014

Gas diffusion layer (GDL) plays a very important role in the function of fuel cell performance. Therefore, the requirements of an ideal GDL include diffusion and distribution of reactants to the catalyst layers, good in plane and thro plane conductivity. Depending on the reactants and operating current densities, the GDL must provide an optimum hydrophobicity and hydrophilicity for gas distribution, water and thermal management (1-3). In order to improve the stability of fuel cell stack, a complete understanding of GDL properties are essential. In the present work, AvCarb MGL370 carbon paper and AvCarb 1071 carbon cloth is used as a substrate material. The effect of PTFE content on the substrate and micro-porous layer on the fuel cell performance is compared in both hydrogen/oxygen and hydrogen/air. The properties of GDL were characterized by experimental setup developed in house for the measurement of gas diffusion coefficient. The properties were also measured using Capillary Flow Porosity meter. The percentage of PTFE on the substrate is varied for both carbon paper as well as carbon cloth ranging from 5 to 20%, however the concentration of PTFE in the micro layer is fixed. The experiments are conducted by keeping constant PTFE loading in the substrate while the concentration PTFE in the micro layer is varied from 15 to 30%. The PEMFC cells were tested at 65 o C and at ambient pressure with relative humidity of hydrogen and air kept at 90% and 80%, respectively. The results were analyzed from the polarization curves. The long-term stability of the cell is evaluated by operating the cell at constant current density. PTFE content in the substrate as well as micro porous layer is important for the performance of fuel cell. The current density achieved in the hydrogen/oxygen is about 1.25A/cm2 at 0.6V, while the same electrode when operated with hydrogen air is 0.5A/cm2 at the same operating voltage (GDL1). Alteration of both substrate and micro-layer PTFE concentration improve the performance to 1.6A/cm2 and 0.7A/cm2 at 0.6V for hydrogen/oxygen and hydrogen/air respectively (GDL2),Fig.1. The effect of hot pressing condition on both carbon cloth as well as carbon paper is also discussed. The pressing pressure conditions varied from 40 to 120kg/cm2. In this paper the performance of both carbon paper and carbon cloth is discussed with respect to PTFE content and pressing conditions. Fig.1: The effect of PTFE content in the substrate and micro layer, ambient pressure, temperature of operation 65 o C, H 2 /O 2 - 100/80%, flow rate H 2 /O 2 is 300/400cc References: 1. G. Velayutham, J. Kaushik , N.Rajalakshmi , K.S.Dhathathreyan , Fuel Cell 7, 314-318 (2007) 2. G. Velayutham, International Journal of Hydrogen Energy 36(22), 14845-14850, (2011) 3. E.Passalacqua , G.Squadrito, F.Lufrano , A.Patti, L.Giorgi . J Appl Electrochem , 31, 449-54 ( 2001)

Yunqi Li, Danping Xiong, Yuwei Liu et al.

Nanotechnology Reviews • 2019

Abstract The catalysts performance degradation is a crucial issue in decay of the polymer electrolyte membrane fuel cell (PEMFC). The effect of Nafion content, dispersity of Pt nanoparticles and selected types of carbon support on the degradation of electrochemical surface area (ECSA) and double layer capacitance (DLC) were experimentally discussed by accelerated stress test (AST). The catalyst with 20wt% Nafion content exhibited better catalyst performance. i.e ., the less DLC and ECSA degradation during AST. Catalysts with well Pt dispersity showed superior %ECSA (the percentage change of ECSA) retention. The heat-treated catalysts exhibited the lowest ECSA and DLC degradation rate due to the larger Pt particle and high carbon corrosion resistance. Moreover, a multi-order model describing the correlation between ECSA and DLC degradation was proposed, providing a vital reference for quantitatively investigating ECSA and DLC degradation in the catalysts with different catalysts structural parameters.

Hegazy Rezk, Ahmed Fathy

Sustainability • 2020

The output power of a fuel cell mainly depends on the operating conditions such as cell temperature and membrane water content. The fuel cell (FC) power versus FC current graph has a unique maximum power point (MPP). The location of the MPP is variable, depending on the operating condition. Consequently, a maximum power point tracker (MPPT) is highly required to ensure that the fuel cell operates at an MPP to increase its performance. In this research work, a variable step-size incremental resistance (VSS-INR) tracking method was suggested to track the MPP of the proton exchange membrane (PEMFC). Most of MPPT methods used with PEMFC require at least three sensors: temperature sensor, water content sensor, and voltage sensor. However, the proposed VSS-INR needs only two sensors: voltage and current sensors. The step size of the VSS-INR is directly proportional to the error signal. Therefore, the step size will become small as the error becomes very small nearby the maximum power point. Accordingly, the accuracy of the VSS-INR tracking method is high in a steady state. To test and validate the VSS-INR, nine different scenarios of operating conditions, including normal operation, only temperature variation, only variation of water content in the membrane, and both variations of temperature and water content simultaneously, were used. The obtained results were compared with previously proposed methods, including particle swarm optimization (PSO), perturb and observe (P&O), and sliding mode (SM), under different operating conditions. The results of the comparison confirmed the superiority of VSS-INR compared with other methods in terms of the tracking efficiency and steady-state fluctuations.

Yang Zhao, Xue Li, Shubo Wang et al.

ECS Meeting Abstracts • 2019

Direct membrane deposition is introduced as a novel polymer electrolyte membrane fabrication method. This method is extended to fabricate a high-performance membrane electrode assembly for polymer electrolyte membrane fuel cell with poly (arylene ether sulfone) nanofibers as effective membrane reinforcements. The nanofibers are directly electrospun onto gas diffusion electrodes. By spray-coating ionomer dispersion into the pore space of nanofiber mats, composite membranes of 15 μm thickness are fabricated. The introduction of the electrically and ionically insulating nanofibers do not hamper the cell performance. At 80 ℃ and 75% relative humidity, the power density of the fuel cell employing direct membrane deposition, 2.85 W/cm 2 , is about 1.36 times higher than that of the reference fuel cell (2.09 W/cm 2 ) with Nafion ® 211. Its cell resistance (28 mΩ·cm 2 ) is much lower than that of the membrane electrode assembly fabricated by the catalyst coating membrane method (46 mΩ·cm 2 ). The performance differences between two fabrication methods are systematically analyzed by electrochemical impedance spectroscopy. Even though the thickness of the polymer electrolyte (15 μm) is much lower than that of Nafion ® 211, it shows much higher internal short resistance because of the existence of nanofibers.

, Dinesh Kumar Madheswaran

Green and Low-Carbon Economy • 2023

This article explores the potential and limitations of Sediment Microbial Fuel Cells (SMFCs) and their deployment for sustainable energy production and environmental remediation. SMFCs use naturally occurring redox gradients in sediments to produce bioelectricity, making them advantageous over conventional energy sources due to their affordability, simplicity, and ability to operate in various environments with minimum maintenance requirements. However, their low power output density restricts their practical applicability. The article discusses the controllable and uncontrollable factors that affect SMFC performance and their influence on SMFC functionality, electrode material, external resistance, electrode spacing, electrode design, electrode immersion dimensions, and catalyst. The article highlights the challenges facing SMFC deployment, particularly in large-scale businesses, such as the need for more scientific literature on SMFCs and inadequate focus on energy metrics.

Richard T. Meyer, Bin Yao

ASME 2006 Fourth International Conference on Fuel Cell Science, Engineering and Technology, Parts A and B • 2005

Recent trends and advances in hydrogen/air Proton Exchange Membrane Fuel Cells (PEMFC) are incorporated into a dynamic control oriented model. This type of model is important for development of control systems for PEMFC powered transportation where unpredictable and widely varying changes in power demand can be expected. Self humidification and low pressure operation are the two major changes to past systems. As a result, a high pressure air compressor, air cooler, and inlet gas humidifiers are no longer required. Also, the likelihood of cathode flooding is reduced. The overall fuel cell model consists of four basic sub-models: anode, cathode, fuel cell body, and cooling. Additionally, the oxidant supply blower, cooling pump, and cooling fan are explicitly incorporated. Mass and energy conservation are applied to each using a lumped parameter control volume approach. Empirical modeling is minimized as much as possible, however it is necessary for model manageability in a control context. Interactions between each subsystem and balance of plant components are clearly defined. The overall model is capable of capturing the transient behavior of the flows, pressures, and temperatures as well as net output power. The influence of the charge double layer effect on transient performance is also explored. Numerical simulations of the system are presented which illustrate the usefulness of the model. Finally, future control work is described.

Borker Mohnish, Suchithra T.V

International Journal of Engineering & Technology • 2018

The need for a sustainable source of energy has catered engineers to discover and develop a biological battery known as Plant Microbial fuel cell. This biological battery operates with the help of electrochemically active bacteria in presence of CO2, sunlight and water. This technique is gaining importance in the field of bioelectricity as it produces clean in-situ energy from living plants without the need to harvest the plant species. Research on these cells have led to the development of various models. One such plant species Setaria faberi was tested for its compatibility in sediment plant microbial fuel cell. Power density of 4.6mW/m2 was obtained when it was tested with cocopeat as a hydroponic media. This paper highlights the suitability of S. faberi in producing sustainable bioelectricity with a hydroponic media. Â

Sameer Al-Asheh, Yousef Al-Assaf, Ahmed Aidan

Energies • 2020

A Microbial Fuel Cell (MFC) is a process in which a microorganism respires and captures the electrons that normally passes through the electron transport system of the organism and produces electricity. This work intends to present the different operating parameters affecting the efficiency of a Microbial Fuel Cell (MFC) process. To study the performance of the process, various materials for the cathode and anode rods with similar size and chape including, copper, aluminum, carbon cloth, steel and brass were considered to determine the combination that leads to the best results. Moreover, different oxidizing agents such as Copper Sulphate and Potassium Hexacyanoferrate were considered. Furthermore, the effects of shapes, sizes and distance between electrodes on the current and voltage were investigated. The power outputs between electrochemical and microbial cells were recorded. In addition, the power, whether expressed as voltage or current, was measured at different conditions and different cell combinations. The power is directly related to the area, volume of the bacterial solution and supplying air and stirring.

M. Aliasghary

Fuel Cells • 2018

Abstract In this study, an interval type‐2 fuzzy proportional–integral–derivative (IT2FPID) controller is designed to be used in the air flow regulation of polymer electrolyte membrane fuel cell (PEMFC) systems. The proposed controller is able to handle the effect of external disturbances and fix the oxygen excess ratio at an appropriate set‐point. Three crisp singletons for the output and two interval type‐2 membership functions for the inputs are defined for the suggested controller. Two conventional controllers including type‐1 fuzzy PID (T1FPID) and ordinary proportional–integral–derivative (PID) are also investigated to evaluate the performance and efficiency of this technique. The results of various simulations indicate that the IT2FPID controller has a better performance and transient response compared to the other approaches.

Calvin H. Li, G. P. Peterson

Advances in Mechanical Engineering • 2009

A combined experimental and analytical investigation of single proton exchange membrane (PEM) fuel cells, during cold start, has been conducted. The temperature influence on the performance of a single PEM fuel cell and the cold start failure of the PEM fuel cell was evaluated experimentally to determine the failure mechanisms and performance. The voltage, current, and power characteristics were investigated as a function of the load, the hydrogen fuel flow rate, and the cell temperature. The characteristics of cold start for a single PEM fuel cell were analyzed, and the various failure mechanisms were explored and characterized. In an effort to better understand the operational behavior and failure modes, a numerical simulation was also developed. The results of this analysis were then compared with the previously obtained experimental results and confirmed the accuracy of the failure mechanisms identified.

Yong Yuan, Qing Chen, Shungui Zhou et al.

Journal of Chemical Technology & Biotechnology • 2011

Abstract BACKGROUND: Electricity can be generated directly from sewage sludge with a microbial fuel cell (MFC), combining degradation of organic matter. This study constructed a novel insert‐type air‐cathode microbial fuel cell (ITAC‐MFC) as an alternative to a sediment‐type MFC and a two‐chambered MFC for the generation of bioelectricity and the degradation of sewage sludge organic matter. Meanwhile, a pH adjustment was carried out to enhance substrate bioavailability of sludge and to suppress methane production in the MFC. RESULTS: A maximum power density of 73 ± 5 mW m −2 was obtained at sludge pH 10.0, much higher than those of 33 ± 3 and 4 ± 0.5 mW m −2 obtained at pH 8.0 and 6.0, respectively. It was observed that the soluble chemical oxygen demand (SCOD) of sewage sludge at pH 10.0 was almost three times greater than that at pH 6.0. At the same time, the total chemical oxygen demand (TCOD) removal and coulombic efficiency (CE) at pH 10.0 were also much higher than at the other two conditions. CONCLUSIONS: The results demonstrated that improved electricity production and organic degradation could be achieved by maintaining the sludge pH at 10.0 in an MFC. ITAC‐MFC offers an attractive alternative for the environmentally‐friendly removal of organic matter in sewage sludge. Copyright © 2011 Society of Chemical Industry

Hugo Guillermo Jimenez Pacheco, Abdel Alejandro Portocarrero Banda, Eric Ivan Vilca Cayllahua et al.

Energies • 2023

The generation of energy through the transformation of polluting waste is a widely explored field and offers advances in green technologies. One of the promising technologies is Microbial Fuel Cells (MFCs). These cells can contain electroactive microorganisms that transform organic waste into electricity by transferring electrons from their metabolism. In this study, a new bacterium capable of producing electricity from the waste of the poultry sector and using copper electrodes, called Av_G1, was identified and isolated. It is phylogenetically related to Citrobacter freundii and Citrobacter Murlinae. This new strain was identified molecularly, biochemically, and phylogenetically; its physiological and morphological characteristics were also studied through a Scanning Electron Microscope (SEM). Biochemical determination was performed using Simmons Citrate Agar, Lysine Iron Medium (L.I.A.), Motility/Ornithine Test, Methyl Red indicator, Enzymes: oxidase and catalase, and Gram stain test. The phylogenetic inference was deduced by bioinformatics tools (MEGA X, JalView, Clustal Omega) and the genetic databases The Ribosomal Database Project—RDP and the National Center for Biotechnology Information (NCBI). A maximum current potential of 0.645 V, a maximum current density of 168.72 ± 14.07 mA/m2, and a power density of 31.05 mW/m2 were recorded. During the monitoring, the physicochemical parameters were taken: pH, Oxide Reduction Potential (ORP), Dissolved Oxygen (DO), conductivity, Total Solids (TDS), and average temperature were recorded. Therefore, the present study shows a new Gram-negative electrogenic bacterium, which can be used for electrochemical processes and applied in MFC with copper electrodes.

Guanghua Wei, Jiabin Lu, Fengjuan Zhu et al.

ECS Meeting Abstracts • 2016

The polymer electrolyte membrane fuel cell (PEMFC) possesses many advantages for both automotive and stationary application, including high energy efficiency, low operating temperature, zero emission, and so on. Aside from the fact that great improvement should be made on its key materials, i.e., the ORR electrocatalysts and proton exchange membrane, it is believed that the PEM fuel cell performance is greatly affected by the operating temperature, gas inlet humidity as well as the flow pattern, and so on [1,2]. Thus, in this work, a 3D steady state model is established to investigate detailedly the effects of the flow pattern (co-flow and counter-flow), the anode and cathode gas inlet relative humidity (RH) on the cell performance. The governing equations of the 3D model result from careful analysis on the electro-chemical reactions, current conservation, membrane proton migration, membrane water transport and water-vapor phase transition. The membrane water transport takes into accounts the electro-osmatic drag and water back diffusion, and the conservation of momentum, species and energy is applied to all components of the PEM fuel cell. Experimental validation is also performed and fits very well with the simulation. Figure 1 shows the current density distribution for different flow patterns: (a), co-flow and (b), counter-flow. The corresponding achievement will offer an efficient guide on the design and performance optimization of PEMFC. Acknowledgements This work was supported in part by National Natural Science Foundation of China (Grant No. 21373135 and 21533005) and Science Foundation of Ministry of Education of China ( Grant No. 413064). References K. Dannenberg, P. Ekdunge, G. Lindbergh, Mathematical model of the PEMFC, Journal of Applied Electrochemistry, 2000, 30: 1377-1387. S.H. Ge, B.L. Yi, A mathematical model for PEMFC in different flow modes, Journal of power sources, 2003, 124: 1-11. Figure 1

Farzaneh Rezaei, Defeng Xing, Rachel Wagner et al.

Applied and Environmental Microbiology • 2009

ABSTRACT Electricity can be directly generated by bacteria in microbial fuel cells (MFCs) from many different biodegradable substrates. When cellulose is used as the substrate, electricity generation requires a microbial community with both cellulolytic and exoelectrogenic activities. Cellulose degradation with electricity production by a pure culture has not been previously demonstrated without addition of an exogenous mediator. Using a specially designed U-tube MFC, we enriched a consortium of exoelectrogenic bacteria capable of using cellulose as the sole electron donor. After 19 dilution-to-extinction serial transfers of the consortium, 16S rRNA gene-based community analysis using denaturing gradient gel electrophoresis and band sequencing revealed that the dominant bacterium was Enterobacter cloacae . An isolate designated E. cloacae FR from the enrichment was found to be 100% identical to E. cloacae ATCC 13047 T based on a partial 16S rRNA sequence. In polarization tests using the U-tube MFC and cellulose as a substrate, strain FR produced 4.9 ± 0.01 mW/m 2 , compared to 5.4 ± 0.3 mW/m 2 for strain ATCC 13047 T . These results demonstrate for the first time that it is possible to generate electricity from cellulose using a single bacterial strain without exogenous mediators.

Yi-Ta Wang, Chyow-San Chiou, Shao-Yu Chang et al.

Journal of Nanoscience and Nanotechnology • 2020

This study focused on an iron phthalocyanine compound with aligned CNTs on the surface of a carbon felt electrode (FePc/CNT/C) to enhance the bio-electro-Fenton microbial fuel cell system cathodes reaction rate of hydrogen peroxide and the electrical plate. Experiments of polarization curves and power density, decolorization of Reactive Black 5 (RB5), and scanning electron microscopy (SEM) measured the characteristics of the cathode plate. FePc/CNT/C presented better electrical properties (open-circuit voltage, maximum current density, and maximum power density) than that of CNT/C and C, as FePc is a catalyst and its planar structure could easily adhere to CNT to enhance the reduction reaction at the cathode and provide higher specific surface area. The optimal decolorization of RB5 dye, as achieved with the FePc/CNT/C electrode, was 61.79% among the three cathode electrodes in the bio-electro-Fenton microbial fuel cell system, and the maximum number of hydroxyl radicals was generated for the cathode electrode of FePc/CNT/C. These results suggest that the bio-electro-Fenton microbial fuel cell system could be applied as an energy-saving and efficient approach for dye-containing wastewater treatment.

Alwahab Alwahab, Pratitis Tri Maharani, Wa Ode Miranda Nur K. et al.

Advance Sustainable Science, Engineering and Technology • 2024

This study examines the potential of biogas liquid waste as a source of electrical energy through microbial fuel cell (MFC) technology. The results showed that biogas effluent in one-room MFC produced a maximum voltage of 1302.2 mV. In the two-room MFC with KMnO4 electrolyte, the voltage reached 1084.3 mV with an electric current of 0.1 mA. At the same time, the two-chamber MFC with K2Cr2O4 advanced a maximum voltage of 1675.8 mV and an electric current of 0.99 mA. Characterization of the MFC substrate showed a decrease in organic matter of biogas liquid waste, with C-organic content of 2.20%, total nitrogen of 1.85%, and C/N ratio of 1.19. The COD value decreased to 500.96 mg/L, while the BOD level decreased to 300.23 mg/L. Bacteria in MFC from biogas effluent are dominantly Gram-positive with rod and Sarcina forms, except for one Gram-negative isolate in the form of Spirillum.

Viatcheslav Fedorovich, Matthew C. Knighton, Eulyn Pagaling et al.

Applied and Environmental Microbiology • 2009

ABSTRACT Exoelectrogenic bacteria are organisms that can transfer electrons to extracellular insoluble electron acceptors and have the potential to be used in devices such as microbial fuel cells (MFCs). Currently, exoelectrogens have been identified in the Alpha -, Beta -, Gamma - and Deltaproteobacteria , as well as in the Firmicutes and Acidobacteria . Here, we describe use of culture-independent methods to identify two members of the genus Arcobacter in the Epsilon p roteobacteria that are selectively enriched in an acetate-fed MFC. One of these organisms, Arcobacter butzleri strain ED-1, associates with the electrode and rapidly generates a strong electronegative potential as a pure culture when it is supplied with acetate. A mixed-community MFC in which ∼90% of the population is comprised of the two Arcobacter species generates a maximal power density of 296 mW/liter. This demonstration of exoelectrogenesis by strain ED-1 is the first time that this property has been shown for members of this genus.