Samuel Simon Araya, Søren Juhl Andreasen, Søren Knudsen Kær

ASME 2014 12th International Conference on Fuel Cell Science, Engineering 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, Stack-Test. 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, temperature, pressure, and stoichiometry at varying current density. Furthermore, procedures for polarization curve recording were also tested both in ascending and descending current directions.

Hwa-Seob Song, Jong-Chul Hong, Gyu-Jin Jang et al.

Journal of Fuel Cell Science and Technology • 2013

In this study, Hyosung demonstrates how a dual-cell structured polymer electrolyte membrane fuel cells (PEMFC) can guarantee the development of a stack with enlarged active area and cost innovation without a change in electrochemical performance and operation conditions. The insertion of insulation part within the bipolar plate and divided membrane electrode assemblies allowed the two individual cells in single layer. This enables the development of highly cost effective stack for PEMFC of a 1 kW class for residential power generators. The decrease in the number of layers can be represented as a cost reduction. We developed a stack of 24 layers with 48 cells, 48 V at open circuit voltage (OCV) and achieved a performance rating of 0.75 V per cell at 250 mA/cm2.

Linde Ren, Jinrong Lu, Hua Liu

New Journal of Chemistry • 2021

Herein, the output power density produced by Fe–Cu–NC- x as the cathode catalyst of a MFC was higher than that of the AC control.

Solène Moulin, Bertrand Légeret, Stéphanie Blangy et al.

Scientific Reports • 2019

Abstract Use of microbes to produce liquid transportation fuels is not yet economically viable. A key point to reduce production costs is the design a cell factory that combines the continuous production of drop-in fuel molecules with the ability to recover products from the cell culture at low cost. Medium-chain hydrocarbons seem ideal targets because they can be produced from abundant fatty acids and, due to their volatility, can be easily collected in gas phase. However, pathways used to produce hydrocarbons from fatty acids require two steps, low efficient enzymes and/or complex electron donors. Recently, a new hydrocarbon-forming route involving a single enzyme called fatty acid photodecarboxylase (FAP) was discovered in microalgae. Here, we show that in illuminated E. coli cultures coexpression of FAP and a medium-chain fatty acid thioesterase results in continuous release of volatile hydrocarbons. Maximum hydrocarbon productivity was reached under low/medium light while higher irradiance resulted in decreased amounts of FAP. It was also found that the production rate of hydrocarbons was constant for at least 5 days and that 30% of total hydrocarbons could be collected in the gas phase of the culture. This work thus demonstrates that the photochemistry of the FAP can be harnessed to design a simple cell factory that continuously produces hydrocarbons easy to recover and in pure form.

Epiphane Zingbe, Damgou Mani Kongnine, Bienvenu M. Agbomahena et al.

Electrochem • 2025

In a plant microbial fuel cell (P-MFC), the plant provides the fuel in the form of exudates secreted by the roots, which are oxidised by electroactive bacteria. The immature plant is hampered by low energy yields. Several factors may explain this situation, including the low open-circuit voltage of the plant cell. This is a function of the development of the biofilm formed by the electroactive bacteria on the surface of the anode, in relation to the availability of the exudates produced by the roots. In order to exploit the fertilising role of biochars, a plant cell was developed from C. citratus and grown in a medium to which 5% by mass of coconut shell biochar had been added. Its effect was studied as well as the distance between the electrodes. The potential of Cymbopogon citratus was also evaluated. Three samples without biochar, with inter-electrode distances of 2, 5 and 7 cm, respectively, identified as SCS2, SCS5 and SCS7, and three with the addition of 5 % biochar, with the same inter-electrode distance values, identified as S2, S5 and S7, were prepared. Open-circuit voltage (OCV) measurements were taken at 6 a.m., 1 p.m. and 8 p.m. The results showed that all the samples had high open-circuit voltage values at 1 p.m. Samples containing 5% biochar had open-circuit voltages increased by 16 %, 8.94% and 5.78%, respectively, for inter-electrode distances of 2, 5 and 7 cm compared with those containing no biochar. Furthermore, the highest open-circuit voltage values were obtained for all samples with C. citratus at an inter-electrode distance of 5 cm. The maximum power output of the PMFC with C. citratus in this study was 75.8 mW/m2, which is much higher than the power output of PMFCs in recent studies.

Yilkal Dessie, Sisay Tadesse, Rajalakshmanan Eswaramoorthy

Journal of Nanomaterials • 2021

In this study, biosynthesized α-MnO2/NiO NPs and chemically oxidative polyaniline (PANI) were synthesized to form ternary composite anode material for MFC. The synthesized materials were characterized with different materials (UV-Vis, FTIR, XRD, TGA-DTA-DSC, SEM-EDX-Gwyddion, CV, and EIS) to deeply examine their optical, structural, morphological, thermal, roughness, and electrocatalytic properties. The degree of surface roughness for α-MnO2/NiO/PANI was 23.65 ± 5.652 nm . This value was higher than the pure α-MnO2, pure PANI, and even α-MnO2/PANI nanocomposite due to surface modification. The total charge storing performance for bare PGE, α-MnO2/PGE, PANI/PGE, α-MnO2/PANI/PGE, and α-MnO2/NiO/PANI/PGE were 5.291, 17.267, 20.659, 23.258, and 24.456 mC. From this, the charge storing performance formed by α-MnO2/NiO/PANI-modified PGE was highest, indicating that this electrode is best in cycle stability and increases its life cycle during energy conversion time in MFC. This is also supported by its effective surface area, having a value of 0.00984 cm2. From this, it is evidenced that the ternary composite catalyst-modified anode facilitates the fast electrocatalytic activity as observed from its high peak current and lower peak-to-peak potential separation ( Δ E p = 0.216 V ) than other electrodes. Such surface modification helps to store more electrical charge by increasing electrical conductivity during its charge/discharge processing time. In addition, the lower charge transfer resistance property with a value of 788.9 Ω and the fast heterogeneous electron transfer rate of ~2.92 s-1 enable to facilitate glucose oxidation, and this enhances to produce high power output and increase wastewater treatment efficiency. As a result, the bioelectrical activity of α-MnO2/NiO/PANI composite-modified PGE was very effective in producing a maximum power density of 506.96 mW m-2 with COD of 81.92%. The above observations justified that α-MnO2/NiO/PANI/PGE serves as an effective anode material in double-chambered MFC application.

B. R. Ringeisen, S. E. Lizewski, L. A. Fitzgerald et al.

Electroanalysis • 2010

Abstract Electrochemically active bacteria (EAB) are prominently found in aquatic environmental sediment samples and wastewater streams, which are known to contain several different types of microorganisms. Even though microbial consortia are found to enhance both Coulombic efficiency and total power output in microbial fuel cells (MFCs), it is currently unknown how many different EAB contribute to current generation in these systems. It is also difficult to track the relative population of different species during MFC operation. We used biological laser printing (BioLP) to isolate different bacterium from complex environmental samples and MFC anolytes. BioLP can be used to print droplets containing a single cell directly from liquid culture, thereby enabling EAB to be sorted from unmodified environmental or MFC samples. Isolated species were identified through 16S rDNA analysis of pure cultures derived from the printed samples. These experiments demonstrate how cell printing can be used as a single‐step method to separate and identify microorganisms from complex environmental samples and operating MFCs.

Daisie D. Boettner, Gino Paganelli, Yann G. Guezennec et al.

Dynamic Systems and Control • 2001

Abstract This paper describes use of a Proton Exchange Membrane (PEM) fuel cell system model for automotive applications in a fuel cell system/battery hybrid configuration. The fuel cell system model has been integrated into a vehicle performance simulator that determines fuel economy and allows consideration of control strategies. The simulator is used to explore relevant regions of the fuel cell-powered hybrid electric vehicle design space by conducting simulations using two simple supervisory-control strategies: thermostatic control and proportional control. During the simulations power provided by the battery and fuel cell system and operational limits on battery state of charge and fuel cell system current density are varied while maintaining minimum component sizing to meet vehicle performance criteria. Analysis of results from these simulations provides component power sizing and limits of operation suitable for development of a more advanced supervisory vehicle control strategy for a fuel cell vehicle.

Akil Ahmad, Mohammed B. Alshammari, Mohamad Nasir Mohamad Ibrahim

Processes • 2023

Microbial fuel cells (MFCs) are thought to be ecologically friendly, despite electron transport and generation challenges. In order to address this, the efficiency of MFCs was investigated using two different anode electrodes made from biomass: graphene oxide (GO) and graphene oxide-metal oxide (GO-MO) (GO-ZnO). After 18 days of operation, the maximum power density for GO was 0.69 mW/m2, whereas the maximum power density for GO-ZnO was 1.05 mW/m2. Furthermore, the ability of MFCs to transform the soluble metal ions (Cd2+, Cr3+, Pb2+, and Ni2+) into an insoluble state was investigated, which is a secondary use of MFCs with significant benefits. In the soluble state of metal ion transformation into an insoluble state, the rate of GO-ZnO was higher (92.71%) than that of GO (81.20%). The outcomes of material, analytical, and biological tests undertaken to validate the efficiency of anodes are presented. It has been shown that using innovative materials as electrodes in MFCs is a potential method for improving electron transport. Furthermore, as an organic substrate, food waste seems to be a viable alternative to more traditional options. In light of these discoveries, we investigate various unanswered issues and possibilities for MFCs. Organic substrate evaluation trials were also included in the present results to demonstrate that organic waste may be a reliable source of MFC performance. This article also has a thorough discussion of food waste oxidation, as well as challenges and future recommendations.

Nurhazirah Mohd Azmi, Nadira Anandita, Husnul Azan Tajarudin et al.

Journal of Physics: Conference Series • 2021

Abstract Fossil fuels have supported the industrialization and economic growth of countries during the past centuries and it is clear that they cannot indefinitely sustain in a longer time. In this study, membrane-less microbial fuel cell (ML-MFC) with mediators-less and air cathode had potential solution to generate electricity power and at the same time could reduce the abundant of food waste (1.64 kg/daily, around 8 tonnes/year) which dumped in the landfill and it’s cost effective device. The ML-MFC operated electrochemically incorporate electrogenic bacteria (EB) acted as a biocatalyst in order to produce electricity. The performance and optimization performance of food waste was evaluated using one-factor-at-a-time (OFAT) method and it was focused to pH for power generation. To determine the generated electricity the polarization curve was used to evaluate the performance of ML-MFC. The chemical oxygen demand (COD) of food waste was studied. The optimization of pH condition in ML-MFC was ranging from 7 to 9. Results showed that pH 8 was the optimum pH for EB strain, Bacillus Subtilis , with the high voltage (807 mV), EB biomass (15.46 mg/L), and power density (373.3 mW/m 2 ) generated. Clearly the pH environment condition affected the efficiency of ML-MFC performance. The increase in EB biomass also increased the voltage in the ML-MFC, proving that EB biomass and voltage were associated with growth.

Elham Shafiee Roudbari, Mohammad Taghi Hamidi Beheshti, Seyed Mehdi Rakhtala

IET Power Electronics • 2019

Nowadays, the demand for electrical energy is increasing, and conventional power systems will face major problems in the future if they cannot generate extra demand for electrical energy. One of the best solutions for solving extra demand for electrical energy is the use of renewable resources to produce energy. The main aim of this study is designing and controlling the microgrid voltage and frequency. This study proposed the voltage and frequency control of an islanded microgrid based on fuzzy logic controller. The system considered for this study consists of Proton‐Exchange Membrane Fuel Cell (PEMFC) that connected to parallel inverters to convert DC voltage to AC voltage. The control structure is based on adaptive droop control and fuzzy voltage control loop. Also, the proposed structure controls active and reactive powers and decreases power losses of the microgrid. Simulation results are presented to show the effectiveness and robustness of the proposed control structure over the conventional proportional–integral controller. It is shown that the proposed controller has good transient response under the output voltage PEMFC variation and load changes as disturbance.

S. Jouttijärvi, Xueli Yao, M. I. Asghar et al.

Research Square • 2020

Abstract A mixed ionic and semiconducting composite in a single-layer configuration has been shown to work as a fuel cell at a lower temperature (500-600 oC) than a traditional solid-oxide fuel cell. The performance of a single-layer fuel cell (SLFC) is often limited by high resistive losses. Here, an eutectic mixture of alkali-carbonates was added to SLFC to improve the ionic conductivity. The dual-phase composite ionic conductor consisted of a ternary carbonate (sodium lithium potassium carbonate, NLKC) mixed with gadolinium-doped cerium oxide (GDC). Lithium nickel zinc oxide (LNZ) was used as the semiconducting material. The LNZ-GDC-NLKC SLFC reached a high power density, 582 mW/cm2 (conductivity 0.22 S/cm) at 600 °C, which is more than 30 times better than without the carbonate. The best results were obtained with the ternary carbonate which decreased the ohmic losses of the cell by more than 95%, whereas the SLFC with a binary carbonate (sodium lithium carbonate, NLC) showed a lower conductivity and performance (243 mW/cm2, 0.17 S/cm at 600°C). It is concluded that adding carbonates to LNZ-GDC will improve the ionic conductivity and positively contribute to the cell performance. These results suggest a potential path for further development of SLFCs, but also imply the need for efforts on up-scaling and stability to produce practical applications with SLFC.

Siddharth Rajupet, Clayton J. Radke, Adam Z. Weber

ECS Meeting Abstracts • 2024

Electrochemical reactions in proton-exchange-membrane (PEM) fuel cells occur within catalyst layers (CL). The catalyst layer consists of a porous network of metal-activated catalyst particles coated with an ion-conducting polymer binder (ionomer) that enables proton transport. Nafion, a perfluorinated sulfonic-acid polymer, is the common binder used and consists of a hydrophobic backbone with negatively charged sulfonic-acid side chains. Prior studies have shown the Nafion distribution in catalyst layers is nonuniform on both the nano 1 and micrometer-scale. 2 This inhomogeneity is thought to impede catalyst-layer performance by limiting proton transport in Nafion-deficient regions and limiting oxygen transport in Nafion-enriched regions. The Nafion distribution in the catalyst layer is governed by the ink from which it is deposited. The catalyst ink is a colloidal slurry consisting of catalyst-activated particles and Nafion typically dispersed in a water-alcohol solvent mixture. Within this ink, some Nafion adsorbs to the surface of catalyst particles, while the remainder is dispersed in solution. Prior studies hypothesize that adsorption in the ink facilitates a more uniform Nafion distribution in the final catalyst layer, thereby improving transport in the catalyst layer. 3,4 Here, we characterize Nafion adsorption in catalyst inks by sedimenting catalyst particles with adsorbed Nafion from inks. The adsorbed Nafion content of the sediment is measured using thermogravimetric analysis. Nafion adsorption to catalyst particles is irreversible and is limited by electrostatic repulsion of the negatively charged Nafion sidechains. We demonstrate that one can control the extent of adsorption by adding mineral acid to the ink to increase the ionic strength and decrease electrostatic repulsion. Through adding acid, the extent of Nafion adsorption to catalyst particles increases by more than a factor of 2 as shown in Figure 1 below. Next, the effect of Nafion adsorption in the ink is correlated to final catalyst-layer performance and properties via cell diagnostics including sheet resistance, polarization performance, and limiting-current measurements. Overall, the talk will elucidate the governing interactions that control Nafion adsorption and how this adsorption affects performance. Acknowledgements This work was funded under the Million Mile Fuel Cell Truck Consortium. References [1] Girod, R., Lazaridis, T., Gasteiger, H. A., & Tileli, V. (2023). Three-dimensional nanoimaging of fuel cell catalyst layers. Nature Catalysis , 6 (5), 383–391. https://doi.org/10.1038/s41929-023-00947-y [2] Orfanidi, A., Rheinländer, P. J., Schulte, N., & Gasteiger, H. A. (2018). Ink Solvent Dependence of the Ionomer Distribution in the Catalyst Layer of a PEMFC. Journal of The Electrochemical Society , 165 (14), F1254–F1263. https://doi.org/10.1149/2.1251814jes [3] Ott, S., Orfanidi, A., Schmies, H., Anke, B., Nong, H. N., Hübner, J., Gernert, U., Gliech, M., Lerch, M., & Strasser, P. (2020). Ionomer distribution control in porous carbon-supported catalyst layers for high-power and low Pt-loaded proton exchange membrane fuel cells. Nature Materials , 19 (1), 77–85. https://doi.org/10.1038/s41563-019-0487-0 [4] Islam, M. N., Mansoor Basha, A. B., Kollath, V. O., Soleymani, A. P., Jankovic, J., & Karan, K. (2022). Designing fuel cell catalyst support for superior catalytic activity and low mass-transport resistance. Nature Communications , 13 (1), 1–11. https://doi.org/10.1038/s41467-022-33892-8 Figure 1

Nur Izzati Iberahim, Nabilah Aminah Lutpi, Li‐Ngee Ho et al.

Environmental Quality Management • 2024

Abstract The purpose of this article is to assess the feasibility analysis of microbial fuel cells (MFCs), particularly in the configuration of dual chamber salt bridge microbial fuel cell (DCSB‐MFC), as a promising approach for simultaneous bioelectricity generation and wastewater remediation. The application of a salt bridge presents an economically viable alternative to the use of a proton exchange membrane, which is known for its high cost, in the construction of MFCs. This arrangement has been demonstrated to offer significant benefits in terms of enhancing the performance of new elements and evaluating operational parameters. However, it also encounters issues related to the total internal resistance (R int ) of the MFCs as well as power density (P). In addition, it has been found that traditional packing materials such activated carbon and gravel demonstrate poor permeability, internal resistance, and slow biofilm growth. Furthermore, there is a necessity to search for electrodes that possess high resistance to corrosion and are cost‐effective to achieve optimal bioelectricity generation. Therefore, this article aims to emphasize the research areas that require attention. By addressing these areas, the actual implementation of this configuration can be brought closer to practical implementation.

Nasser A. M. Barakat, Rasha H. Ali, Hak Yong Kim et al.

Nanomaterials • 2022

Carbon nanofiber-decorated graphite rods are introduced as effective and low-cost anodes for industrial wastewater-driven microbial fuel cells. Carbon nanofiber deposition on the surface of the graphite rods could be performed by the electrospinning of polyacrylonitrile/N,N-Dimethylformamide solution using the rod as nanofiber collector, which was calcined under inert atmosphere. The experimental results indicated that at 10 min electrospinning time, the proposed graphite anode demonstrates very good performance compared to the commercial anodes. Typically, the generated power density from sugarcane industry wastewater-driven air cathode microbial fuel cells were 13 ± 0.3, 23 ± 0.7, 43 ± 1.3, and 185 ± 7.4 mW/m2 using carbon paper, carbon felt, carbon cloth, and graphite rod coated by 10-min electrospinning time carbon nanofibers anodes, respectively. The distinct performance of the proposed anode came from creating 3D carbon nanofiber layer filled with the biocatalyst. Moreover, to annihilate the internal cell resistance, a membrane-less cell was assembled by utilizing a poly(vinylidene fluoride) electrospun nanofiber layer-coated cathode. This novel strategy inspired a highly hydrophobic layer on the cathode surface, preventing water leakage to avoid utilizing the membrane. However, in both anode and cathode modifications, the electrospinning time should be optimized. The best results were obtained at 5 and 10 min for the cathode and anode, respectively.

, Sahrani Saharuddin, Amalyah Febryanti et al.

Jurnal Sumberdaya Alam dan Lingkungan • 2024

Plant-Microbial Fuel Cell (P-MFC) is a green technology because it uses a biocathode in the cathode compartment and also uses microorganisms to break down the chemical energy of organic matter into electrical energy. In this research, molasses and Saccharomyces cereviceae were used as substrates and Ceratophyllum demersum as a biocathode in the cathode compartment. The purpose of this study was to determine the potential variation in plant weight of C. demersum as a biocathode in the P-MFC system. The results of this study indicated that the maximum current at the biocathode was at a weight of 70 g, namely 0.180 mA with a power density value of 13.664 mW.m-2 and the maximum potential difference at the biocathode was at a weight of 40 g, which as 0.310 mV with a power density value of 30.787 mW.m-2. Therefore, coontail water plant has the potential as biocathode.

Yi Zuo, Defeng Xing, John M. Regan et al.

Applied and Environmental Microbiology • 2008

ABSTRACT Exoelectrogenic bacteria have potential for many different biotechnology applications due to their ability to transfer electrons outside the cell to insoluble electron acceptors, such as metal oxides or the anodes of microbial fuel cells (MFCs). Very few exoelectrogens have been directly isolated from MFCs, and all of these organisms have been obtained by techniques that potentially restrict the diversity of exoelectrogenic bacteria. A special U-tube-shaped MFC was therefore developed to enrich exoelectrogenic bacteria with isolation based on dilution-to-extinction methods. Using this device, we obtained a pure culture identified as Ochrobactrum anthropi YZ-1 based on 16S rRNA gene sequencing and physiological and biochemical characterization. Strain YZ-1 was unable to respire using hydrous Fe(III) oxide but produced 89 mW/m 2 using acetate as the electron donor in the U-tube MFC. Strain YZ-1 produced current using a wide range of substrates, including acetate, lactate, propionate, butyrate, glucose, sucrose, cellobiose, glycerol, and ethanol. Like another exoelectrogenic bacterium ( Pseudomonas aeruginosa ), O. anthropi is an opportunistic pathogen, suggesting that electrogenesis should be explored as a characteristic that confers advantages to these types of pathogenic bacteria. Further applications of this new U-tube MFC system should provide a method for obtaining additional exoelectrogenic microorganisms that do not necessarily require metal oxides for cell respiration.

Obaid ur Rehman, Amber Fishan Zafar

Journal of Electrochemical Science and Engineering • 2017

<p class="PaperAbstract">The performance of proton exchange membrane (PEM) fuel cell majorly relies on properties of gas diffusion layer (GDL) which supports heat and mass transfer across the membrane electrode assembly. A novel approach is adopted in this work to analyze the activity of GDL during fuel cell operation on a large-scale model. The model with mesh size of 1.3 million computational cells for 50 cm<sup>2</sup> active area was simulated by parallel computing technique via computer cluster. Grid independence study showed less than 5% deviation in criterion parameter as mesh size was increased to 1.8 million cells. Good approximation was achieved as model was validated with the experimental data for Pt loading of 1 mg/cm<sup>2</sup>. The results showed that GDL with higher thermal conductivity prevented PEM from drying and led to improved protonic conduction. GDL with higher porosity enhanced the reaction but resulted in low output voltage which demonstrated the effect of contact resistance. In addition, the compressive force reduced the porosity under the rib regions which resulted in lower gas diffusion and heat and water accumulation.</p>

Shuiyun Shen, Chao Wang, Qinglei Zhang et al.

ECS Meeting Abstracts • 2016

To further improve the cell performance of a proton exchange membrane fuel cell (PEMFC), thus meeting the high requirement for its automotive and stationary application, great efforts have been made on the optimization of the flow field pattern[1,2]. In this work, two novel flow field patterns are proposed and the influences on the cell performance are investigated. Both two novel flow field designs lead to superior cell performance than the conventional flow field patterns do, and this can be attributed to their superiority in removing water at high current densities while increasing the flow velocity near the outlet. The velocity magnitude in flow fields is examined and compared through the computational fluid dynamics modeling. 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 [1] Soler, J., E. Hontanon, and L. Daza, Electrode permeability and flow-field configuration: influence on the performance of a PEMFC. Journal of Power Sources, 2003. 118(1): p. 172-178. [2] Lee, B., K. Park, and H.-M. Kim, Numerical Optimization of Flow Field Pattern by Mass Transfer and Electrochemical Reaction Characteristics in Proton Exchange Membrane Fuel Cells. Int. J. Electrochem. Sci, 2013. 8: p. 219-234.

Pedro Oliveira, Francisco Brójo, Rafael Domingues

Volume 6: Energy • 2024

Abstract Water-in-diesel emulsions (WiDE) are an alternative fuel to be used in diesel engines capable of offering the benefits of higher engine efficiency and lesser pollutant emissions. This work aims to show how differences in WiDE fuel temperatures may impact its combustion properties and how they translate into different performances and emissions. An emulsion composed of diesel, 8% (m/m) of distilled water, and 3% (m/m) surfactant was performed in laboratory by mechanical homogenization and tested in a single-cylinder Hatz 1B40 Direct Injection (DI) diesel engine coupled to an eddy current dynamometer, an emission gas analyzer, and an opacimeter. The tests were performed for the fuel temperatures of 40°C and 50°C, and at 75% of the maximum considered engine load at four different speeds. The results show that higher emulsion temperatures lead to lower NO emissions, higher CO emissions, and decreased thermal efficiency.

S. Jouttijärvi, Xueli Yao, M. I. Asghar et al.

Research Square • 2019

Abstract A mixed ionic and semiconducting composite in a single-layer configuration has been shown to work as a fuel cell at a lower temperature (500-600 oC) than a traditional solid-oxide fuel cell. The performance of such single-layer fuel cell (SLFC) is often limited by high resistive losses. Here, an eutectic mixture of alkali-carbonates was added to SLFC to improve the ionic conductivity. The dual-phase composite ionic conductor consisted of a ternary carbonate (sodium lithium potassium carbonate, NLKC) mixed with gadolinium-doped cerium oxide (GDC). Lithium nickel zinc oxide (LNZ) was used as the semiconducting material. The LNZ-GDC-NLKC SLFC reached a high power density, 582 mW/cm2 (conductivity 0.22 S/cm) at 600 °C, which is more than 30 times better than without the carbonate. The best results were obtained with the ternary carbonate which decreased the ohmic losses of the cell by more than 95%, whereas a binary carbonate (sodium lithium carbonate, NLC) showed a lower conductivity and performance (243 mW/cm2, 0.17 S/cm at 600°C). It is concluded that adding carbonates to the LNZ-GDC will improve the ionic conductivity and positively contribute to the cell performance. These results will help to design better-performing SLFCs in the future and highlight the potential of SLFCs as a candidate for future electricity generation.

Hong Gun Kim, Lee Ku Kwac, Sung Soo Kang et al.

Materials Science Forum • 2007

An experimental study is carried out to investigate the performance and the practical application of polymer electrolyte membrane fuel cell(PEMFC) with the double-tied catalyst layers in a Membrane Electrolyte Assembly (MEA). Characteristics of PEMFC depend highly on the conditions such as gas pressure, temperature, thickness, supplied oxidant type (Oxygen/Air) as well as humidification. They are controlled under the same condition for the comparison of the simulation. Testing condition is fixed at 60sccm and 70°C in anode and cathode, respectively. The humidification about 15% the performance is improved no humidification rather. The current density is increased around 20% significantly when pure oxygen gas is provided as an oxidant. It is found that measured values of unit cell voltage and current are influenced strongly by the type and amount of oxidant, which give more enhanced values in case of oxygen compared to the ambient air as oxidant.

Xiaoyi Jiang, Xintong Gao, Ke Yang et al.

Environmental Engineering Research • 2024

Iron minerals can significantly impact the performance of soil microbial fuel cells (Soil-MFCs) through extracellular electron transfer (EET). Introducing defects into iron minerals has been shown to reinforce the microbial dissolution process. In this study, oxygen-rich vacancy defects were successfully incorporated into hematite (DHem), resulting in enhanced Soil-MFCs performance. Voltage measurement and Polarization curves demonstrated that the addition of DHem yielded the highest electricity output of 408.96 mV and the highest power density of 324.97 mW/m2. Liquid chromatography revealed that the system with DHem exhibited the most effective phenanthrene degradation at 61.42%, with a 40.70% increase in degradation near cathode areas. The introduction of defects led to increased dissolution of Fe(II) in hematite. The dissolved Fe(II) showed a significant positive correlation with both electricity generation and phenanthrene degradation, confirming that the introduction of defects strengthened the long-distance electron transfer capability by enhancing the dissolution of hematite. In addition, after adding iron minerals, the abundance of Petrimonas, Pseudomonas, Trichococcus, and Azoarcus was increased, which were all important function microorganisms in the system. We concluded that the introduction of defects in hematite can enhance the overall performance of Soil-MFCs by enhance electron transfer and microbial community structure.

Arpita Nandy, Mohita Sharma, Senthil Venkatesan et al.

Energies • 2019

This study aims to provide insight into the cost-effective catalyst on power generation in a microbial fuel cell (MFC) for treatment of municipal sludge. Power production from MFCs with carbon, Fe2O3, and Pt electrodes were compared. The MFC with no coating on carbon generated the least power density (6.72 mW·m−2) while the MFC with Fe2O3-coating on carbon anodes and carbon cathodes generated a 78% higher power output (30.18 mW·m−2). The third MFC with Fe2O3-coated carbon anodes and Pt on carbon as the cathode catalyst generated the highest power density (73.16 mW·m−2) at room temperature. Although the power generated with a conventional Pt catalyst was more than two-fold higher than Fe2O3, this study suggests that Fe2O3 can be investigated further as an efficient, low-cost, and alternative catalyst of Pt, which can be optimized for improving performance of MFCs. Electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) results demonstrated reduced resistance of MFCs and better charge transfer between biofilm and electrodes containing coated anodes compared to non-coated anodes. Scanning electron microscopy (SEM) was used to analyze biofilm morphology and microbial community analysis was performed using 16S rRNA gene sequencing, which revealed the presence of known anaerobic fermenters and methanogens that may play a key role in energy generation in the MFCs.

Ravi Shankar, Prasenjit Mondal, Shri Chand

Environmental Progress & Sustainable Energy • 2014

This work deals with the simultaneous generation of electricity and removal of organic load from synthetic wastewater containing eqimolar concentration of glucose and glutamic acid. The effect of initial COD (mg/L), anodic pH and metals (Zn 2+ , Cr 6+ , and Fe 3+ ) concentration on the generation of current density and voltage has been studied. Although, the amount of COD removed increases with increase in the initial COD value from 500 to 2500 mg/L, the maximum generation of current density (19 mA/m 2 ) and voltage (14.8 mV), after 7 days of operation, is achieved at the initial COD value of 1500 mg/L at anodic pH value of 7. Difference in the anodic and cathodic pH has also been observed maximum (∼1) at the initial COD value of 1500 mg/L. Addition of metals initially increases the voltage and power density generation, attains a maximum value at a certain metal concentration and decreases thereafter with increase in metal concentration. Optimum concentration of metals, that is, 8 mg/L Zn 2+ , 7 mg/L Cr 6+ , and 10 mg/L Fe 3+ in the solution produces maximum voltage of 142, 490, and 321 mV, after 7 days of operation, respectively. Corresponding maximum power densities are 6.9, 508, and 192 mW/m 2 , respectively. The present process seems to have maximum current density and voltage generation capacity in comparison to some recently reported literatures on membrane less MFCand is able to reduce COD value below permissible limit with the initial COD value ≤1250 mg/L. © 2014 American Institute of Chemical Engineers Environ Prog, 34: 255–264, 2015

Alfiah Alif, Muhamad Jalil Baari, Amalyah Febryanti

International Journal of Science, Technology & Management • 2023

Sediment Microbial Fuel Cell (MFC) is a technology that can convert chemical energy into electrical energy through the process of nutrient degradation by microbes. Sediment taken from the bottom of shrimp ponds was added as a source of microbes, while fish and shrimp wastewater were used as a source of nutrients for microbes. This study aims to measure the performance of the SMFC system on fish effluent and shrimp effluent to produce bio-electricity while reducing the waste load. The research method was experimental laboratories. The treatment given was the different types of electrodes, namely zinc-copper and aluminum-copper. In addition, 0.2 M KMnO4 electrolyte solution was used. This study consisted of four stages: the manufacture of nutrients from fish and shrimp wastewater, the manufacture of a dual chamber MFC bioreactor, the measurement of electrical values, and the analysis of waste quality. Experiments were carried out for 30 days by measuring electricity every 24 hours. The average value of electricity generated in the nutrients of fish wastewater with Zn/Cu electrodes was 0.705 V and Al/Cu was 0.472 V. Meanwhile, the average value of electricity in shrimp wastewater nutrients with Zn/Cu electrodes was 0.630 V and Al/Cu was 0.625 V. The number of colonies after adding sediment in the shrimp wastewater sample were 8.9 x 106 CFU/mL, the fish wastewater sample was 9.5 x 106 CFU/mL. It indicates the presence of microorganisms that play a role in the SMFC system

Sundas Bahar Yaqoob, Showkat Ahmad Bhawani, Rokhsana Mohammed Ismail Abdulrahman

Journal of Chemistry • 2021

Microbial fuel cells (MFCs) are a sustainable approach for the remediation of metals and the simultaneous production of energy. This paper highlighted the usage of mango extract to produce electricity as an organic source for bacteria and reduce metal ions from wastewater. The observed results were 51 mV in 15 days with 500 Ω of external resistance. The whole operation was carried out at room temperature. The observed current and power density were 28.947 mA/m2 and 0.972 mW/m2, respectively. The internal resistance was 150 Ω, which is lower than external resistance. The remediation performance varied with the metal ions as follows: Pb (II) shows 75%, Cd (II) shows 74.11%, and Cr (III) shows 80.50%. Finally, the detailed working mechanism of the present study, MFC challenges, and future research directions are covered in this paper.

Shizhe Peng, Jia Li, Yihan Hu et al.

Small • 2024

Abstract A decent stretchability is of paramount significance to operate microbial fuel cell (MFC) under mechanically dynamic conditions. However, it remains a grand challenge to fabricate fully stretchable MFC without compromising its power output. Here, using Shewanella oneidensis MR‐1 ( S. oneidensis ) as the model electrogenic bacteria, the study demonstrates a fully stretchable MFC device that can operate with a stretchability of 75%. The design takes advantage of a stretchable and ion‐conductive polyurethane membrane, which encapsulates the biohybrids composed of S. oneidensis and reduced graphene oxide (rGO) on the polydimethylsiloxane (PDMS) current collector for synchronous stretching. It is discovered that the “stretchable” living biohybrids can sustain an adaptive bio‐current output under stretching/releasing stimulation. The design also employs a stretchable air cathode. The stabilized peak power density of the stretchable MFC follows an increasing trend with the applied strain, and reaches 5.0 ± 0.7, 5.9 ± 0.9, 6.2 ± 1.1, 6.6 ± 1.4 µW cm −2 at strains of 0%, 25%, 50%, and 75%, respectively (n = 3). At 75% strain, the stretchable MFC yields a maximum current output of 104 ± 27 µA cm −2 and an open‐circuit voltage of 283 ± 30 mV (n = 3). The results provide insights to design stretchable MFCs to power the next‐generation on‐skin devices, soft robotics, and sustainable electronics.

Norhazirah Azhar, Thye-Foo Choo, Nur Ubaidah Saidin et al.

Engineering Headway • 2025

In the fabrication of fuel cell electrodes, applying catalyst ink onto a substrate is crucial. The performance of the proton exchange membrane fuel cell (PEMFC) is subsequently impacted by how the catalyst is applied onto substrate as well as in terms of its resulting morphology. In this study, a direct catalyst ink spraying approach was done in order to investigate transfer efficiency and surface morphology for different concentrations of ink. The concentration of catalyst ink used in the spraying process are 0.5, 1.0, 1.5, 2.0 and 2.5 mg/ml with fixed loading of 1.0 mg/cm 2 . The transfer efficiency of the catalyst inks was calculated neglecting human error during spraying. The coating thickness and distribution of the resulting catalysts were analysed via Field Emission – Scanning Electron Microscope (FESEM).

Jason Rugolo, Brian Huskinson, Michael J. Aziz

ECS Transactions • 2011

We develop a model for a regenerative hydrogen-chlorine fuel cell including four voltage loss mechanisms: hydrogen electrode activation, chlorine electrode activation, chlorine electrode mass transport, and ohmic loss through the membrane. The dependencies of each of these losses as a function of two "operating parameters", acid concentration and temperature; and five ``engineering parameters", exchange current densities at both electrodes, membrane thickness, acid diffusion layer thickness, and cell pressure, are explored. By examining this large parameter space, we predict the design target and ultimate limitations to the performance characteristics of this cell. We identify chlorine electrode activation as the dominant contribution to the loss for low current density, high-efficiency operation and membrane resistance as the dominant contribution to the loss at maximum galvanic power density. We conclude that a "dream" cell should be attainable with further research that operates at greater than 90% voltage efficiency at current densities >1A/cm2.

Theofilos Kamperidis, Pavlos K. Pandis, Christos Argirusis et al.

Sustainability • 2022

The aim of this study is to examine the effect of food waste condensate concentration (400–4000 mg COD/L) on the performance of two microbial fuel cells (MFCs). Food waste condensate is produced after condensing the vapors that result from drying and shredding of household food waste (HFW). Two identical single-chamber MFCs were constructed with different cathodic assemblies based on GoreTex cloth (Cell 1) and mullite (Cell 2) materials. Linear sweep voltammetry (LSV) and electrochemical impedance spectroscopy (EIS) measurements were carried out to measure the maximum power output and the internal resistances of the cells. High COD removal efficiencies (>86%) were observed in all cases. Both cells performed better at low initial condensate concentrations (400–600 mg COD/L). Cell 1 achieved maximum electricity yield (1.51 mJ/g COD/L) at 500 mg COD/L and maximum coulombic efficiency (6.9%) at 400 mg COD/L. Cell 2 achieved maximum coulombic efficiency (51%) as well as maximum electricity yield (25.9 mJ/g COD/L) at 400 mg COD/L. Maximum power was observed at 600 mg COD/L for Cell 1 (14.2 mW/m2) and Cell 2 (14.4 mW/m2). Impedance measurements revealed that the charge transfer resistance and the solution resistance increased significantly with increasing condensate concentration in both cells.

Whitney G. Colella, Viraj Srivastava

ASME 2012 10th International Conference on Fuel Cell Science, Engineering and Technology • 2012

The widespread use of combined heat and power (CHP) distributed generation (DG) for buildings could significantly increase energy efficiency and reduce greenhouse gas and air pollution emissions. By displacing both electricity from conventional centralized power plants and heat from decentralized boilers, CHP DG could reduce primary feedstock fuel consumption in the U.S. by approximately 20%, or 6,000 terawatt hours. However, optimally integrating CHP DG within buildings is challenging. This work aims to elucidate optimal system sizing and design of micro-CHP fuel cell systems (FCSs) integrated with commercial buildings. This modeling effort compares and contrasts the performance of high temperature polymer electrolyte membrane (PEM) fuel cell systems (HTPEM FCSs) and solid oxide fuel cell (SOFC) systems for commercial buildings. A parallel research effort is independently analyzing measured data from HTPEM FCSs installed in commercial buildings. Measured data from that effort is integrated into this modeling work. In certain regions, there has been a research and development and commercialization trend moving from using low temperature PEM FCSs (e.g. with a stack temperature of around 80°C) to using HTPEM FCSs (e.g. with a stack temperature of around 160°C) and to using SOFC systems (e.g. with a stack temperature of around 700°C) for CHP building applications, given the higher temperature of the available waste heat from these systems. In this work FCS performance data is coupled with building energy system models from the U.S. Department of Energy (DOE) using EnergyPlus™ whole-building energy simulation software. Using these baseline reference commercial building model data, parameters are examined including heat demand for space heating and for domestic hot water heating over time, temperatures and water flow rates associated with this heat demand, and building electrical demand over time, to evaluate FCS integration within the building. Examining the data obtained through the simulation exercise in this work, it is found that in a large office building, with heat demand temperatures in the range of 82°C for space heating and 60°C for hot water heating, an HTPEM FCS with an exhaust temperature of 47°C can potentially access, at a maximum, 19% of the total building heating demand. By contrast, in a small office building, with heat demand temperatures in the range of 23°C (supply air temperature) for space heating and 60°C for hot water heating, it is found that this HTPEM FCS can potentially access, at a maximum, 90% of the total building heating demand. Examining the temporal characteristics of the building heat demand to determine FCS sizing, it is found that a maximum of 50% of the time, the heat demand can be served with an HTPEM FCS with a thermal capacity of 8 kilowatts (kW) (0.05 kW for small office) and an electrical capacity of approximately 4.5 kilowatts-electric (kWe) (0.45 kWe for small office). A maximum of 80% of the time, the heat demand can be served with an HTPEM FCS with a thermal capacity of 85 kW (0.16 kW for small office) and an electrical capacity of approximately 73 kWe (0.14 kWe for small office). The simulation results further indicate that an SOFC has advantages over an HTPEM FCS that originate from its higher exhaust temperature (between 25°C and 315°C), which allows it to meet a greater percentage of the building heating demand (up to 100%). This enables an SOFC to serve a larger percentage of the building stock and a wider variety of building heating systems. Furthermore, if the CHP FCSs are grid independent (i.e., it is not possible to supply electrical power back to the grid), then the heat-to-power ratio of an FCS can be an important parameter. In such a scenario, the heat-to-power ratio of an SOFC (approximately 0.33) is closer to the heat-to-power ratio of a building (approximately 0.081, averaged over an entire year). In a stand-alone configuration, when the CHP DG has a heat-to-power ratio that more closely matches that of the buildings, the utilization of the DG system is likely to be higher and its economics and environmental impacts more favorable.

Venkata Yarlagadda, Trung Van Nguyen

ECS Meeting Abstracts • 2014

The hydrogen electrode in a H 2 -Br 2 fuel cell (Figure 1) has high active surface area because of the nano catalyst particle on carbon support material that is used. Current electrodes used for the bromine reactions are made of high porosity carbon fiber based gas diffusion media that have very low surface area. Currently, to obtain high surface area, multiple layers of this material are used. While this leads to an increase in the surface area, it also leads to high ionic and molecular transport resistance. To overcome this problem, our research group has developed a high surface area carbon diffusion material. This material is made by growing multiwall carbon nanotubes directly on the carbon fiber substrate (Figure 2). In this presentation, we will discuss the advantages of this material and compare the discharge/charge performance of an acid-based H 2 -Br 2 fuel cell with this material versus that with conventional electrode materials. Acknowledgements This work was funded by NSF through grant number EFRI-1038234 and DOE/ARPA-E under award number DE-AR0000262.

S. Cano-Andrade, A. Herna´ndez-Guerrero, M. Von-Spakovsky et al.

Volume 6: Energy Systems: Analysis, Thermodynamics and Sustainability • 2006

Proton exchange membrane (PEM) fuel cells are promising candidates for power generation in transportation, portable, and stationary applications due to their high full and partload efficiencies, low operating temperatures, high power densities, fast startups, and potential system robustness. A vital component for this new technology is the bipolar plate since it supplies the fuel and oxidant, removes the products of reaction, collects the current produced, and provides mechanical support for the cells in the stack. However, the bipolar plate adds weight, volume, and cost to the fuel cell. A way to offset this, at least partially and perhaps significantly, would be by improving the bipolar plate flow field layout so that the power density of the cell or stack (parallel cell arrangement) is improved. To that end, this paper proposes an innovative radial flow field design for which a three-dimensional model of the heat, mass, and charge transport and electrochemistry in a single fuel cell has been developed and solved via a finite volume approach. This model is based on the following supposition: steady state, isothermal, single phase, isotropic materials and mass transfer in three directions. Predictions of current density as well as the pressure losses, velocities, and flow field contours are made and presented.

Derek W. Fultz, Po-Ya Abel Chuang

Volume 9: Heat Transfer, Fluid Flows, and Thermal Systems, Parts A, B and C • 2008

Two fuel cell architectures, differing only by the surfaces onto which the electrodes were applied, have been analyzed to determine the root causes of dissimilarities in performance. The basic proton exchange membrane fuel cell (PEMFC) is comprised of the proton transporting membrane, platinum-containing anode and cathode electrodes, porous carbon fiber gas diffusion media (GDM), and flow fields which deliver the reactant hydrogen and air flows. As no optimal cell design currently exists, there is a degree of latitude regarding component assembly and structure. Catalyst coated diffusion media (CCDM) refers to a cell architecture option where the electrode layers are coated on the GDM layers and then hot-pressed to the membrane. Catalyst coated membrane (CCM) refers to an architecture where the electrodes are transferred directly onto the membrane. A cell with CCDM architecture has tightly bonded interfaces throughout the assembly which can result in lower thermal and electrical contact resistances. Considering the fuel cell as a 1-D thermal system, the through-plane thermal resistance was observed to decrease by 5–10% when comparing CCDM to CCM architectures. This suggests the thermal contact resistance at the electrode interfaces was significantly reduced in the hot-press process. In addition, the electrical contact resistances between the electrode and GDM were observed to be significantly reduced with a CCDM architecture. This study shows that these effects, which have a potential to increase performance, can be attributed to the hot-press lamination process and use of CCDM architecture.

Usman Javaid, Jamshed Iqbal, Adeel Mehmood et al.

PLOS ONE • 2022

A Polymer Electrolytic Membrane Fuel Cell (PEMFC) is an efficient power device for automobiles, but its efficiency and life span depend upon its air delivery system. To ensure improved performance of PEMFC, the air delivery system must ensure proper regulation of Oxygen Excess Ratio (OER). This paper proposes two nonlinear control strategies, namely Integral Sliding Mode Control (ISMC) and Fast Terminal ISMC (FTISMC). Both the controllers are designed to control the OER at a constant level under load disturbances while avoiding oxygen starvation. The derived controllers are implemented in MATLAB/ Simulink. The corresponding simulation results depict that FTISMC has faster tracking performance and lesser fluctuations due to load disturbances in output net power, stack voltage/power, error tracking, OER, and compressor motor voltage. Lesser fluctuations in these parameters ensure increased efficiency and thus extended life of a PEMFC. The results are also compared with super twisting algorithm STA to show the effectiveness of the proposed techniques. ISMC and FTISMC yield 7% and 20% improved performance as compared to STA. The proposed research finds potential applications in hydrogen-powered fuel cell electric vehicles.

Hikaru Takamata, Soichiro Shimotori, Shoichi Hidai et al.

ECS Meeting Abstracts • 2024

Toshiba’s Stationary Fuel Cell System Toshiba Energy Systems & Solutions Corporation is developing hydrogen solution, which is a key technology to achieve carbon neutral. Now we are manufacturing the pure hydrogen fuel cell systems for stationary application. This fuel cell systems have some models up to 100kW, and in order to provide the larger electricity than 100kW, the 100kW system can be operated connecting several units up to 1MW. Toshiba's fuel cell systems have been achieved stable, long-term operation, high durability, and high energy efficiency. These features are realized by internal water management cell stack conflagration using porous carbon bi-polar plates. The porous bi-polar plates can humidify reactant gases supplied as vapor from the surface of the porous bi-polar plates and removes produced water through the porous bi-polar plates by the pressure difference between the reactant gases and the coolant water. This technology realizes ideal conditions in terms of water activity entire active area, suppressing overpotentials due to flooding and temperature and water activity distribution. This technology enables stable continuous operation up to 1 week and design life of 80,000 hours confirmed by demonstration tests, which is one of the highest in the world. Recent trends in fuel cell development include the growing expectation and demand for higher capacity and long durability fuel cell systems for stationary applications such as carbon neutral complexes and data centers, etc. In addition, demand for high power density fuel cell systems for large commercial mobility vehicles, such as buses and trucks, is also increasing. In order to meet this demand, Toshiba is developing elemental technologies for higher performance fuel cells. Development of advanced high performance fuel cells In order to improve cell performance, it is necessary to reduce ohmic, activation, and diffusion polarizations. Among these three overpotentials, a reduction of diffusion polarization is particularly important to achieve operation up to the high current density. To reduce diffusion polarization, the flow field of bi-polar plates must be designed to improve the limiting current density by efficient gas supply to the catalyst layer and to reduce mass transport resistance in the gas diffusion layer and catalyst layer. Toshiba has focused on reducing this diffusion polarization and is working on the flow field design using numerical simulation. As an example, Toshiba has developed the advanced numerical simulation by introducing mass transfer models of water evaporation and water absorption on the surface of a porous bi-polar plates into a commercially available electrochemical reaction and thermal fluidics 3D simulator. This porous bi-polar plates model was then used to perform parametric study of the flow field design, and determine parameters in terms of gas diffusivity, electrical resistance, and temperature and humidity distribution. And then, the advanced cell that incorporating designed bi-polar plates, thinner components, and a new catalyst was fabricated and evaluated. Figure 1 shows comparison of cell performance between conventional and advanced cells. The limiting current density of advanced cell is 3.6 times larger than that of conventional cell due to simulation-based flow field design and optimization of operating pressure. The application of these development items and optimization of operating conditions reduced each polarization and achieved a current density twice that of conventional cell. In the future, we aim to achieve even higher performance by improving catalytic activity and reducing cell resistance through thinner components. Figure 1

Reena Meshram, Shailesh Kumar Jadhav

NewBioWorld • 2019

Microbial fuel cells (MFCs) are the electrochemical systems that harness electron from the reduction of organic compounds using microbes as a catalyst. 3 combinations from 4 electrodes that are, Zn (14.9cm×4.9cm), Carbon (14cm×1.5cm), Cu (14.9cm×4.9cm) and Al (14cm×4.5cm) were assessed . Zn-C, as an anode-cathode combination produced maximum voltage of 1.1±0.03V and current 1.5±0.12mA. In present study,gram negative non-fermentative staphylococcus bacterium was isolated from a mediator-less microbial fuel cell, fed with rice bran oil refinery wastewater operated in fed-batch manner. The isolate produced potential of 1.01±0.01V and current of 1.24±0.03mA using synthetic wastewater. The newly isolated bacterium has potential of generating electricity in MFC system and may hold many possibilities with different wastewater as well as in practical applications.

Akimitsu Ishihara, Shigenori Mitsushima, Nobuyuki Kamiya et al.

1st International Fuel Cell Science, Engineering and Technology Conference • 2002

An exergy (available energy) analysis has been conducted on a typical polymer electrolyte fuel cell (PEFC) system using methanol. The material balance and enthalpy balance were calculated for the PEFC system using methanol steam reforming, and the exergy flow was obtained. Based on these results, the exergy loss in each unit was obtained, and the difference between the enthalpy and exergy was discussed. The exergy loss in this system was calculated to be 178kJ/mole MeOH for the steam reforming process of methanol. Although the enthalpy efficiency approached unity as the recovery rate of the waste heat from the cell approached unity, the exergy efficiency remained around 0.45 since the cell’s operating temperature of 80°C is low. It was also found that the cell voltage should exceed 0.82V in order to obtain the exergy efficiency of 0.5 or higher. A direct methanol fuel cell (DMFC) was analyzed using the exergy and compared with the methanol reforming PEFC. In order to obtain the exergy efficiency higher than that of PEFC with steam reforming, the cell voltage of the DMFC should be 0.48V or greater at the current density of 600mA/cm2.

Ömer ER, Ali CAVAK, Adnan ALDEMİR et al.

MANAS Journal of Engineering • 2020

In this study, carbon nanotube (CNT) supported Pd catalysts at varying Pd molar ratios are prepared via NaBH4 reduction method. Catalysts prepared for hydrazine electrooxidation are characterized via N2 adsorption-desorption measurements (BET), X-ray photoelectron spectroscopy (XPS), and transmission electron microscope (TEM). Electrochemical measurements are performed using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) techniques by CHI660E potentiostat in a three-electrode system. According to the characterization results, Pd/CNT catalysts are successfully synthesized. For 5% Pd/CNT catalyst, the average particle size and the surface area determined as 5.17 nm and 773.10 m2 g-1 via TEM and BET, respectively. Between the Pd containing (0.1-20 wt %) CNT supported catalysts prepared, 5% Pd / CNT catalyst shows the best current density as 6.81 mA cm-2 (1122.63 mA mg-1 Pd). Furthermore, 5% Pd/CNT catalyst shows littlest charge transfer resistance (Rct) compared to Pd/CNT catalysts.