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.

S KC, U Dhakal, P Karki et al.

Journal of Physics: Conference Series • 2023

Abstract The influence of operating variables like temperature, pressure, humidity etc. needs to be reduced to optimize the performance of proton exchange membrane fuel cells (PEMFCs). A model that can accurately simulate the real operating conditions of a fuel cell can be used to optimize its performance. This paper develops and simulates a mathematical model for PEMFC in steady-state operating conditions. A steady state model is built in MATLAB-Simulink environment. The effects of different operating variables on the performance of the PEMFC have been studied. The parameters include operating temperature and reactant flow pressure. The results in the form of polarization curve, efficiency, power and current density have been analysed to compare the fuel cell behaviours. The results show good conformity with other existing models.

S. Sai Mohan, G. Sanjana, D. Avinash et al.

Current Journal of Applied Science and Technology • 2020

Weeding is an important and labour intensive agricultural operation and about 1/3rd of the cost of cultivation is accounted towards weed control operation alone. Any delay and negligence in weeding operation effects the crop yields up to 30-40%. Today the agricultural sector requires non-chemical weed control that safeguards consumers demand for high quality food products and pay special attention to food safety. The objectives of the study was to evaluate the performance of power weeder by evaluating the energy consumption and cost economics of power weeder in sugarcane crop. The evaluation was conducted at soil different moisture contents at 30,45 and 60 days after sowing (DAS) at different speeds of weeder. The bulk density decreased from 0.84 to 0.65 g cm-3 with increased soil moisture content from 7±1 to 12±1 per cent. The field capacity of power weeder varied from 0.0347 to 0.137 ha h-1 when operated with 3 forward speeds at 30, 45 and 60 DAS. The weeding efficiency of power weeder is in the range of 98.74 to 91.22% at 0.584 km h-1, 96.80 to 84.93% at 1.35 km h-1 and 94.67 to 73.72% at 4.153 km h-1. The minimum and maximum plant damage is observed at a forward speeds of 0.584 km h-1 and 4.153 km h-1. When operated at lower speeds the plant damage will be minimum whereas operating at high speeds will result in maximum plant damage. Field machine index of the weeder is observed as 0.83, 0.82 and 0.864 for 30, 45 and 60 DAS. The cost of weeding per hectare is calculated as Rs.3,878 ha-1 and Rs.8000 ha-1 for mechanical and traditional weeding, respectively. It can be started and operated by farmer or any unskilled labour with ease. Also working with power weeder in between the rows is easy with a very less maintenance cost.

Helen K White, Clare E Reimers, Erik E Cordes et al.

The ISME Journal • 2009

Abstract This study examines changes in diversity and abundance of bacteria recovered from the anodes of microbial fuel cells (MFCs) in relation to anode potential, power production and geochemistry. MFCs were batch-fed with plankton, and two systems were maintained at different potentials whereas one was at open circuit for 56.8 days. Bacterial phylogenetic diversity during peak power was assessed from 16S rDNA clone libraries. Throughout the experiment, microbial community structure was examined using terminal restriction fragment length polymorphism. Changes in cell density of key phylotypes, including representatives of δ-, ɛ-, γ-proteobacteria and Flavobacterium-Cytophaga-Bacteroides, were enumerated by quantitative PCR. Marked differences in phylogenetic diversity were observed during peak power versus the final time point, and changes in microbial community structure were strongly correlated to dissolved organic carbon and ammonium concentrations within the anode chambers. Community structure was notably different between the MFCs at different anode potentials during the onset of peak power. At the final time point, however, the anode-hosted communities in all MFCs were similar. These data demonstrate that differences in growth, succession and population dynamics of key phylotypes were due to anode potential, which may relate to their ability to exploit the anode as an electron acceptor. The geochemical milieu, however, governs overall community diversity and structure. These differences reflect the physiological capacity of specific phylotypes to catabolize plankton-derived organic matter and exploit the anode of an MFC for their metabolism directly or indirectly through syntrophy.

Dmitrii Andreevich Chirkov, Aleksandr Dmitrievich Korotayev, Evgenii Aleksandrovich Chabanov

International Journal of Power Electronics and Drive Systems (IJPEDS) • 2022

Currently, linear motors find increasingly wide application in various industrial sectors. These motors feature a range of advantages including the absence of compound mechanical power transmissions between a motor and an actuator, simple design, and performance reliability. These advantages determine application of linear motors in electric drive systems of a range of industrial mechanisms including liquid metal and melt transfer units, various transport systems, and metal working and grinding machines. As an illustration, the article addresses submersible cylindrical linear alternating current electronic engines used for rodless oil extraction. Practice shows that the overall efficiency of such units is extremely low. This article is dedicated to the determination of performance and power/angle characteristics of such linear motors, their main energy indicators 𝑐𝑜𝑠𝜑 and efficiency at various supply voltage frequencies. It is shown that 𝑐𝑜𝑠𝜑 at all supply voltage frequencies remains very high, while the efficiency is extremely low. The main way to increase the engine efficiency is to increase the frequency of its supply voltage as much as possible. It is proposed to extend the results obtained to other possible industrial applications of linear electric drives.

H. Y. Kanaan, S. Georges, I. Mougharbel et al.

RE&PQJ • 2024

In this paper, a high-current two-stage DC-DC converter fed by a Proton Exchange Membrane Fuel Cell (PEMFC) is studied. The converter consists of two three-phase full-bridge inverters connected through three AC coupled inductors. The mathematical models of both converter and PEMFC are first presented, and a control scheme that ensures a high power factor at the AC stage and a regulated voltage at the DC load is then implemented. The performance of the proposed control system is verified through digital simulations.

Vladimir Gurau, Thomas A. Zawodzinski, J. Adin Mann

Journal of Fuel Cell Science and Technology • 2008

To date, multiphase computational fluid dynamics models for proton exchange membrane (PEM) fuel cells failed to provide even a qualitative depiction of the fuel cell water management. This was primarily due to the inability to capture two-phase phenomena in the cathode catalyst layer and the water saturation equilibrium at the interface between the fuel cell components. A model without the cathode catalyst layer cannot capture dominant mechanisms of water transfer and cannot explain correctly the fuel cell performance. We propose a multifluid, multiphase model consisting of separate transport equations for each phase. The model accounts for gas- and liquid-phase momentam and species transport in the cathode channel, gas diffusion layer (GDL), and catalyst layer and for the current density, ionomer-phase potential, and water content in the catalyst coated membrane. The model considers water produced at cathode by (I) electrochemical reaction, (II) change of phase, and (III) parallel, competing mechanisms of water transfer between the ionomer distributed in the catalyst layer and the catalyst layer pores. Liquid water is transported in the GDL and the catalyst layer due to liquid pressure gradient and in the channel due to gravity and two-phase drag. We have developed a transport equation for the water content. The source/sink terms of the transport equation represent the parallel, competing mechanisms of water transfer between the ionomer phase and the catalyst layer pores. They are (I) sorption/desorption at nonequilibrium and (II) electro-osmotic drag by the secondary current. Another distinguishing feature of this model is the capability to capture water saturation equilibrium at channel-GDL and GDL–catalyst layer interfaces. The computational results are used to study the dynamics of water transport within and between the fuel cell components and the impact of the GDL and catalyst layer properties on the amount of water retained in the fuel cell components during operation. A new dominant mechanism of water transfer between the ionomer distributed in the catalyst layer and the catalyst layer pores is identified. The amount of water retained in GDL is determined by GDL permeability and its pore size at the interface with the channel. The amount of water retained in the cathode catalyst layer is determined by the saturation equilibrium at the interface with the GDL. Models based on the two-phase mixture model are not applicable to PEM fuel cell electrodes.

Xiaobai Li, Yang Song, Zhuang Liu et al.

High Performance Polymers • 2013

A series of triple-layer membranes were prepared based on a sulfonated polyimide (SPI) and a traditional sulfonated poly(ether ether ketone) (SPEEK) polymer matrix. Compared with the single-component membranes (pure SPI and SPEEK), the multicomponent membranes exhibited better comprehensive performance. Interestingly, the triple-layer membranes possessed improved mechanical properties, lower water uptake, and swelling ratio than those of the corresponding blend membranes. When the contents of SPI were 30 and 40%, the triple-layer membranes even had lower methanol permeability (3.42 and 2.61 × 10 −7 cm 2 s −1 , respectively) than that of the pure SPI membrane (3.51 × 10 −7 cm 2 s −1 ). The proton conductivity of the triple-layer membranes was in the range of 0.117–0.149 S cm −1 at 100°C. All the results suggest that the triple-layer membranes have sufficiently excellent performance to be applied in fuel cells.

Ji Yeon Kim, Mehdi Mortazavi, Sung Yong Jung

ECS Meeting Abstracts • 2024

Polymer electrolyte membrane fuel cells (PEMFCs) offer numerous advantages, such as low operating temperatures, ease of start-up and shutdown, and high power density. Recent researches have focused on enhancing their performance for various industrial applications, particularly in transportation fields including vehicles and drones. The gas diffusion layer (GDL) in PEMFC plays a key role in the transport of fuel, oxygen, and water. The physical and chemical degradation of GDL adversely affects the water management resulting in performance deterioration. A major cause of GDL degradation in PEMFCs is the generation of hydrogen peroxide (H₂O₂) during the electrochemical reaction. H₂O₂ lead PTFE loss and carbon corrosion, and this degradation is irreversible. Although several studies demonstrate techniques for recovering performance for the reversible degradation, limited research exists on restoring performance in irreversibly degraded PEMFCs. This study proposes a novel approach for the performance recovery in irreversibly degraded PEMFCs by superimposing acoustic pressure waves on the oxygen gas flow which enhances the water management ability [1]. To investigate the effect of proposed recovery technique, performances were compared with or without the superimposed acoustic pressure waves using a unit cell having 25 cm² active area. The 19 % decrease in performance with aged GDL was observed due to the reduction in the water management capability caused by the decrease of hydrophobicity. The superimposed acoustic pressure waves led to a performance recovery of up to 9. This recovery is attributed to the enhanced removal of accumulated water on the GDL surface through external excitation, which facilitated oxygen supply and improved water discharge. The proposed the water management method can offer a promising solution for recovering performance in irreversibly degraded PEMFCs and has the potential to improve both performance and durability. Acknowledgement This work was supported by the National Research Foundation of Korea(NRF) grant funded by the Korea government(MSIT) (No. RS-2023-00208497, RS-2023-00219369). Reference [1] Kim, J. Y., Mortazavi, M., & Jung, S. Y. (2024). Improving polymer electrolyte membrane fuel cell performance and preventing flooding by exciting gas flow. Journal of Power Sources , 617 , 235181.

Kritika Sharma, Shrihari Sankarasubramanian, Zhongyang Wang et al.

ECS Meeting Abstracts • 2023

The development of high-power fuel cells could advance the electrification of the transportation sector, including marine and air transport. Liquid-fueled fuel cells are particularly attractive for such applications as they obviate the issue of fuel transportation and storage. Herein, we report a direct methanol hydrogen peroxide fuel cell (DMHPFC) for high-power propulsion applications that delivers 0.8 W cm 2 peak power density by using a pH gradient-enabled microscale bipolar interface (PMBI) to effectively meet the incongruent pH requirements for methanol oxidation/peroxide reduction reactions. DMHPFCs are an important alternative to hydrogen-fed polymer electrode membrane fuel cell (PEMFCs) and anion exchange membrane fuel cells (AEMFCs) due to methanol’s high energy density compared to that of hydrogen and superior kinetics of hydrogen peroxide reduction reaction as compared to Oxygen. A unit volume of Hydrogen gas stored at a pressure of approximately 69 MPa corresponds to volume-specific energy density of roughly 2.1 kWh/l while 39% volume of aqueous methanol and 41% volume of aqueous hydrogen peroxide corresponds to volume-specific energy density of 9.2 kWh/l. So, DMHPFC’s energy density is approximately four times higher than hydrogen fuel cell’s energy density and is comparable to gasoline which contains roughly 9.2 kWh/l of available bond energy. The theoretical potential for Methanol oxidation reaction (MOR) in basic medium is lower than that in an acidic medium (-0.78 V vs. -0.02 V) and the theoretical potential for the Hydrogen peroxide reduction reaction (HPRR) is higher than that for oxygen reduction (1.77 V vs. 1.23 V in acidic medium). This results in the highest theoretically possible cell voltage for cells with alkaline anodes and acidic cathodes. We achieved sustained operation of the DMHPFC with an alkaline anode and an acidic cathode by incorporating our pH-gradient-enabled microscale bipolar interface (PMBI). However, the system exhibits a relatively low Faradaic efficiency of 50% due to the parasitic evolution of O 2 by the decomposition of H 2 O 2 . The O 2 evolution results in a mixed potential at the cathode due to the occurrence of both the HPRR (E 0 = 1.77 V versus standard hydrogen electrode [SHE]) and the oxygen reduction reaction (ORR); (E 0 = 1.23 V versus SHE), lowering the overall cell potential. The O 2 surface coverage reduces the available sites for the HPRR, effectively deactivating the catalyst. Electrocatalysts exhibiting a combination of high HPRR activity and selectivity (by inhibiting H 2 O 2 decomposition, and hence inhibiting ORR) would result in higher faradic efficiency and have been the subject of sustained interest. Here, we examine an alternate reactant-transport engineering approach to improve the overall cell potential and cell performance of the DMHPFC. Our reactant-transport engineering approach has examined the impact of reactant flowrate, flow velocity, residence time, and flow regime (via the Reynolds number ([Re]) on DMHPFC performance. Balancing the competing demands of high residence time to improve Hydrogen peroxide reduction reaction (HPRR) rates with high flowrates to detach adsorbed O 2 , we identify a critical Re and Damkholer number (Da) to efficiently exclude O 2 gas bubbles while maintaining large current densities during the operation of a DMHPFC. Reactant-transport engineering of the cathode flow field architecture and fuel flowrates mitigates parasitic hydrogen peroxide decomposition and oxygen reduction reactions and lessens cathode passivation by oxygen bubbles. DMHPCs fulfilling these criteria provide a power density of >500 mW cm -2 at 1.0 V compared to state-of-the-art polymer electrolyte membrane fuel cells (PEMFCs) that typically operate at 0.75 V. The high peak power density of 800 mW cm -2 at 1.1 V may offer a pathway to reduce fuel cell stack size for propulsion applications. Our work paves the way for such other liquid fuel cells with hydrogen peroxide as the oxidant and enabled with PMBI resulting in significantly improvement in the performance. Figure 1

Vivek Yadav, Deepanshu, Harshit Mittal et al.

Research Square • 2025

Abstract Proton Exchange Membrane (PEM) fuel cells offer great potential in terms of green energy solutions but degrade over a period of time based on diverse operation and material aspects. Based on the data obtained from PEM Fuel Cell Dataset with polarization as well as impedance at diverse operations, this study makes use of machine learning algorithms for predicting degradation of fuel cell. Following preprocessing by imputation of missing values via mean imputation, exploratory data analysis was performed via heatmaps and key visualizations. Fifteen machine learning models involving linear and nonlinear regressors, decision trees, ensemble models, and neural networks were trained to predict important performance metrics like cell voltage, power density, and impedance characteristics. Model performance was conducted with Mean Absolute Error (MAE), Mean Squared Error (MSE), Root Mean Squared Error (RMSE), and R² Score, where the Extra Trees Regressor performed best with an MAE of 0.00099 and an R² score of 0.996. These results show the potential of machine learning to forecast fuel cell degradation, enabling proactive maintenance and increased system reliability. Future work will explore real-time deployment of predictive models for enhanced operational effectiveness in real-world systems.

Chongxue Zhao, Haihang Zhang, Zheng Huang et al.

Research Square • 2023

Abstract In this paper, a gradient pore size structure gas diffusion layer (GDL) was prepared. The pore structure of microporous layers (MPL) were controlled by pore-making agent ammonium bicarbonate (NH 4 HCO 3 ). The effects of the two-stage MPL and the different pore size structures in the two-stage MPL on the performance of proton exchange membrane fuel cells (PEMFC) were investigated. The results of the conductivity and water contact angle tests showed that the GDL had outstanding conductivity and good hydrophobicity. The results of the pore size distribution test indicated that the introduction of a pore-making agent altered the pore size distribution of the GDL as well as increased the capillary pressure difference within the GDL. Specifically, there was an increase in pore size within the 7-20 μm and 20-50 μm ranges, which improved the stability of water and gas transmission within the fuel cell. The maximum power density of the GDL03 was increased by 37.1% at 40% humidity, 38.9% at 60% humidity, and 40.3% at 100% humidity when compared to the commercial GDL29BC in a hydrogen-air environment. The design of gradient MPL ensured that pore size between carbon paper and MPL changed from an initially abrupt state to a smooth transition state, which greatly improved water and gas management capabilities of proton exchange membrane fuel cell.

Ratikanta Nayak, Bentham Science Publisher Harilal, Prakash Chandra Ghosh

Current and Future Developments in Nanomaterials and Carbon Nanotubes • 2022

Polymer nanocomposite is a new kind of material that offers to substitute traditionally filled polymers. The nanomaterial polymer matrix inter-phase area increases drastically due to the inherent high surface-to-volume ratio resulting in remarkably enhanced properties compared to the pristine polymers or their conventional counterpart filled nanocomposites. Nanocomposites have several novel properties such as nonlinear optical properties, electronic conductivity and luminescence. Therefore, their use has been projected in many areas like chemical sensors, polymer electrolyte membrane fuel cell (PEMFCs), electroluminescent devices, batteries, electrocatalysis, smart windows and memory devices. PEMFCs embody a potential candidate for electrochemical energy generation in the twenty-first century due to their better efficiency and environmentally friendly nature. Proton exchange/Polymer electrolyte membrane (PEM) plays a vital role in the PEMFCs. Currently, PEM like Nafion and Flemions are widely used in PEMFC, which have certain drawbacks such as fuel cross-over through the membrane, low operating temperature, and high cost. The researchers from several laboratories across the globe have put their extreme effort into preparing a novel polymer electrolyte membrane with high proton conductivity, better long-term stability, improved thermal stability, high peak power density (PPD), and less fuel crossover with minimum cost. The advent of nanotechnology has brought a new scope to this research area. The hybrid (organic polymer with inorganic nanoparticle) nanocomposite membrane has developed into an exciting alternative to the conventional polymer membrane applications. It provides an exclusive blend of inorganic and organic properties and helps to overcome the drawbacks of align="center"pristine polymer membranes. In this book chapter, we have focused on different nanomaterials and their effect is analyzed in polymer electrolyte nanocomposite membranes for PEMFC applications.

Yung-Neng Cheng, Shih-Wei Cheng, Ruey-Yi Lee

Journal of Fuel Cell Science and Technology • 2014

A solid oxide fuel cell (SOFC), which is a kind of fuel cell (FC) converting chemical energy into electricity directly without mechanical parts, has potential for the clean and efficient power generation from a wide variety of fuels ranging from hydrocarbons to renewables and coal-derived fuels. The Institute of Nuclear Energy Research has been committed to developing the SOFC technology since 2003 and the cell test is one of the working items in the project. Cells are the most important components in an SOFC stack, which are responsible for the electrical output functioning, as the heart in the human body, to the stack. Before stacking, it is essential to examine and evaluate the electrical performance of the cells that could be used in our stacks. There are two commercial cells tested in this paper. For both cell A, an anode supported cell, and cell B, an electrolyte supported cell, the cells with a lower open circuit voltage at a higher operating temperature are contributed by the Nernst equation. The I-V curve for a lower operating temperature with a steeper slope at the low current zone is credited to the increase of activation polarization from the triple phase boundary. Comparison between cell A and cell B, the electrical performance of cell A is better than that of cell B due to cell A possessing a lower total resistance at the same operating temperature.

Zina Belkhiri, Mostefa Zeroual, Hocine Ben Moussa et al.

Journal of Renewable Energies • 2023

A fuel cell is a promising energy conversion system that will eventually become the first-choice for producing power because of its clean or zero-emission nature. A steady-state, two-dimensional mathematical model with a complete set of governing equations valid in different components of a PEM fuel cell was developed to illustrate the temperature and water content effects on proton exchange membrane (PEM) fuel cell performance. This model considers the transport of species and water along the porous media: gas diffusion layers (GDL) anode and cathode, and the membrane of PEMFC fuel cell. To improve the kinetics of electrochemical reactions at the electrodes and thus reduce the activation overvoltage: increase the gas diffusion electrodes reduce the drop ohmic, especially in the proton conductive membrane through an increase in ionic conductivity. The electrochemical performance of a fuel cell will be strongly depend temperature and water content.

Yun Wang, Pengtao Sun

ASME 2010 8th International Fuel Cell Science, Engineering and Technology Conference: Volume 1 • 2009

This paper develops a 3D dynamic model for polymer electrolyte fuel cells (PEFCs also called PEM fuel cells) and investigates the internal physicochemical processes that occur during PEFC transients as well as fuel cell dynamic responses. This model couples various dynamic mechanisms in the key components of PEFC, such as electrochemical double-layer discharging/charging, species transport, heat transfer, and membrane water uptake. The model is further discretized for 3D numerical simulations with focus on transient operation upon the step change in power density. The numerical results show that over/undershoot dynamic responses may take place during transient. A detailed picture of internal operating conditions, such as water and current density distributions, is presented to develop a comprehensive understanding of fuel cell transient during power/load variation.

O. D. Adeniyi, B. Ngozichukwu, M. I. Adeniyi et al.

Ghana Journal of Science • 2021

Melon seed husk (MSH) biochar was used in a single cell direct carbon fuel cell (DCFC) as an alternative biofuel. The DCFCs belong to a generation of energy conversion devices that are characterised with higher efficiencies, lower emission of pollutants and MSH biochar as the fuel. Several analytical techniques (proximate, ultimate and thermo-chemical analysis) were employed to analyse the characteristics of the biomass fuel, their effects on the cell’s performance, and the electrochemical reactions between the fuel and the electrolyte in the system. High carbon content and calorific values are some of the parameters responsible for good performances. The performance of a lab-scale DCFC made of ceramic tubes using molten carbonate electrolyte was investigated. Binary carbonates mixture (Na2CO3-K2CO3, 38-62 mol.%) was used as electrolyte and the waste MSH carbonised at 450oC as biofuel. A practical evaluation of the fuel used in the DCFC system was conducted, for varying temperature of 100 - 800oC. The maximum open circuit voltage (OCV) was 0.71 V. With an applied load resistance and active surface area of 5.73 cm2 the maximum power density was 5.50 mWcm-2 and the current density was 29.67 mAcm-2 at 800oC.

Ayisa Timothy Terna, Muhammad Ramatu Gogo, Mohammed Jibrin Ndejiko

Journal of Basics and Applied Sciences Research • 2025

The concerns about global warming are gradually causing sensitive debate globally therefore its pertinent at this period to intensify the quest for alternative sources of energy. The potential of abattoir effluent to generate electricity at room temperature via microbial fuel cell technology has been demonstrated. Microbial fuel cell is a bio electrochemical system which utilizes bacteria to generate electricity. This study was conducted to evaluate the potential of bacteria to generate electricity through microbial fuel cells with abattoir effluent serving as a substrate. The study was carried out using a dual chambered microbial fuel cell. And the set up was monitored for a period of seven days. Readings were taken at intervals of two hours all through the experiment. The highest voltage generated was 0.58V on the first day and the lowest voltage recorded was 0.05V on the seventh day. The results from this study indicate that bacteria in microbial fuel cells can utilize abattoir effluent converting chemical energy to electrical energy. The low voltage generated makes microbial fuel cells less efficient than traditional energy generation methods. There is still much to be learned about complex interactions between micro organisms and electrode materials in microbial fuel cells. Hence, further research is needed to develop more efficient, durable and cost effective materials for microbial fuel cells.

Huu Linh Nguyen, Younghyeon Kim, Jaesu Han et al.

Volume 7: Energy • 2023

Abstract A proton exchange membrane fuel cell (PEMFC) of heavy-duty truck is operated in very harsh conditions, but it requires more longevity than a passenger vehicle. The current durability strategy for vehicular fuel cells is geared towards passenger vehicles, hence this study employs response surface analysis to develop a durability strategy for heavy-duty fuel cell trucks. The study uses a physics-based model to predict the degradation of PEMFC under truck operation mode. The model is validated using experimental data from a 20-cell PEMFC stack, which is operated for 2000 hours under the world harmonized vehicle cycle (WHVC) mode. The study employs a response surface method (RSM) to select the power output and degradation rate as object functions. Results indicated that as the operating temperature increases, the power output increases, but the degradation is accelerated. By contrast, increasing gas inlet temperature decreases power output and degradation rate. Higher relative humidity at the cathode and anode leads to increase fuel cell and lower voltage degradation. Therefore, the optimal operating conditions for the fuel cell to minimize voltage degradation are high levels of humidity, moderate cell temperatures, and moderate gas inlet temperatures. The study suggests that the optimal operating conditions are anode and cathode relative humidity of 100%, a fuel cell temperature of 61°C, and a gas inlet temperature of 57°C.

Song Qiu, Luyang Wang, Yimei Zhang et al.

International Journal of Environmental Research and Public Health • 2022

Most microbial fuel cell (MFC) sensors only focus on the detection of mixed solutions with respect to the chemical oxygen demand (COD) or toxicity; however, the concentrations of the individual analytes in a mixed solution have rarely been studied. Herein, we developed two types of MFC sensors, adapted with sodium acetate (MFC-A) and glucose (MFC-B) as organic substrates in the startup period. An evident difference in the sensor sensitivities (the slope value of the linear-regression curve) was observed between MFC-A and MFC-B. MFC-A exhibited a superior performance compared with MFC-B in the detection of sodium acetate (4868.9 vs. 2202 mV/(g/L), respectively) and glucose (3895.5 vs. 3192.9 mV/(g/L), respectively). To further compare these two MFC sensors, the electrochemical performances were evaluated, and MFC-A exhibited a higher output voltage and power density (593.76 mV and 129.81 ± 4.10 mW/m2, respectively) than MFC-B (484.08 mV and 116.21 ± 1.81 mW/m2, respectively). Confocal laser scanning microscopy (CLSM) and microbial-community analysis were also performed, and the results showed a richer anode biomass of MFC-A in comparison with MFC-B. By utilizing the different sensitivities of the two MFC sensors towards sodium acetate and glucose, we proposed and verified a novel method for a simultaneous test on the individual concentrations of sodium acetate and glucose in a mixed solution. Linear equations of the two variables (concentrations of sodium acetate and glucose) were formulated. The linear equations were solved according to the output voltages of the two MFC sensors, and the solutions showed a satisfactory accuracy with regard to sodium acetate and glucose (relative error less than 20%).

Mahir M Said, Asia A Saad, Geoffrey R John et al.

Tanzania Journal of Science • 2023

The access to electricity is still not reliable in Tanzania. Whilst, there are several locations within the country that have wastewater cites that are not economically used to produce electricity. At the University of Dar es Salaam (UDSM), there are main grid power, and few scattered solar panels. This study was intended to bridge the divide between the current increasing power demands of the UDSM by exploiting not so much used sources, such as electric energy from wastewater. This study was undertaken to develop a Microbial Fuel Cell (MFC) prototype fed by sewage in Dar es Salaam, for electricity generation using cost effective materials for the cathode compartment. The collection of samples took place using sewage substrates from the UDSM oxidation ponds. The untreated sewage was collected from oxidation ponds. Preliminary experiments were carried out to identify the cathode and substrate that produced better results in terms of volts and current output. Aluminium produced the most desirable results compared to copper, stainless steel and mild steel in all the substrates. On the other hand, untreated sewage with aluminium/carbon electrodes produced higher voltage and current compared to treated sewage with the same electrodes. Thereafter, a prototype of the MFC was developed by connecting three single chambered cells in series of 628 cm3 volume of untreated sewage with aluminium and carbon electrodes. The prototype generated a stable voltage of 1.73 V and a current of 0.07 mA recorded for a period of one hour. The power generated was enough to light a 6.25 mW LED bulb of 25 mA across a 100 Ω resister. Therefore, untreated sewage produced more power in MFCs with aluminium/carbon electrodes compared to the other tested materials.
 Keywords: Aluminium electrodes, charcoal electrode, alternative energy source, wastewater

Hany S. Abdo, Asiful H. Seikh, Ubair Abdus Samad et al.

Crystals • 2021

Methane is an extensively accessible green energy that can be obtained organically just by way of through natural gases. However, using methane in fuel at ambient temperature conditions is quite challenging, due to its high thermodynamically stability. In this present investigation, the feasibility of using methane in the low-temperature microbial fuel-cell (MFC) with an unadulterated culture of Methylococcus chroococcus without the inclusion of any additional electron mediators is investigated. The microbial fuel cell setup was prepared using a salt bridge. Through potentiodynamic study, power density, and OCV, it can be seen that the setup delivers a sufficient amount of voltage and power as the days progress. Electrochemical Impedance Spectroscopic investigations also depict the fact that the cell required roughly one day to balance out, and kept working at full force for up to seven days. This work exhibits the chance of creating power utilizing methane as one of the main carbon sources at ambient temperature with an M. chroococcus unadulterated culture as the direct electron-transporting MFC biocatalyst.

Roya Morovati, Mohammad Hoseini, Abooalfazl Azhdarpoor et al.

Sustainability • 2022

Microbial fuel cell (MFC) with a modified anode is one of the new methods to increase MFC efficiency. This study synthesized an anode modified with cobalt manganese oxide (MnCo2O4@CF) on carbon felt (CF) by easy hydrothermal method and binder-free. Chemical oxygen demand (COD) was measured with and without diclofenac (DCF). According to SEM results, MnCo2O4 was uniformly dispersed on the anode electrode surface. Moreover, the maximum power density in COD (1000 mg/L), 48 h. condition without DCF (726 mA/m2) was 165 ± 0.012 mW/m2 and with DCF concentration of 20 mg/L, it was 308 ± 0.013 mW/m2 (992 mA/m2). In addition, in the presence of 10 mg/L DCF concentration, the maximum COD removal efficiency was 82% ± 1.93 at 48 h. COD removal efficiency without DCF was 94.67% ± 0.02 at 72 h. After 72 h, the maximum removal efficiency of COD and DCF in the carbon anode was 41% ± 1.15 and 9.5% ± 0.23, respectively. Moreover, the maximum DCF removal efficiency using a MnCo2O4 anode was 56% ± 0.55, at 48 h; the initial COD concentration was 500 mg/L, and the DCF concentration was 20 mg/L. This research showed that coating the anode with MnCo2O4 could lead to the increased growth of microorganisms on the surface of the anode, decreased load transfer resistance, increased power density, and more removal of COD and DCF. As a result, the performance of fuel cells with modified anode and removal of DCF increased compared to anode with CF-MFC. Thus, the performance of fuel cells with modified anode and removal of DCF increased compared to anode with CF-MFC.

Julie C. Fornaciari, Samay Garg, Xiong Peng et al.

Journal of The Electrochemical Society • 2022

With a growing demand for electricity, clean hydrogen production and usage can be an asset not only to mitigate emissions but for long-term energy storage as well. Hydrogen gas, a high-density energy carrier, can be made through electrolysis in charging mode and generate electricity via a fuel cell in discharging mode in a unitized regenerative fuel cell (URFC). While URFCs reduce cost by combining the charging and discharging modes into a singular device, switching between modes becomes burdensome, and water management is a major challenge. One way to mitigate these issues is to operate the entire system in the vapor phase. Vapor-phase operation simplifies the physics of the system but will introduce losses within the system, primarily ohmic and mass transport during the charging mode. In this study, we explore the performance of a Proton-Exchange-Membrane (PEM)-URFC under vapor-phase conditions and the impact of different PEMs, feed gases, and relative humidity on the performance and durability. By tailoring operating conditions and membrane, the vapor-URFC achieves a roundtrip efficiency of 42% and a lifetime of 50,000 accelerated stress test cycles for fully humidified feeds. Discussion of vapor-URFC for energy storage and extensions to look at various applications shows the promise of this technology.

J. Cha, C. Kim, S. Choi et al.

Water Science and Technology • 2009

For simultaneous carbon and nitrogen removal via single stream, a microbial fuel cell (MFC) coupled with an aeration chamber and a bio-cathode was investigated. Without catalysts and any additional buffer, the MFC produced electricity continuously and the power density reached 1.3 W/m3 at a loading rate of 1.6 kg COD/m3 d. Simultaneously, the COD and the nitrate removal rate were 1.4 kg COD/m3 d and 67 g NO3-N/m3 d, respectively. When the hydraulic retention time was changed from 6 to 0.75 hours, the power density significantly increased from 0.2 to 10.8 W/m3 due to an increase of cathodic potential. When the aeration chamber was removed and the nitrate was injected into the cathode, the power density increased to 3.7 W/m3. At a high recirculation rate of 10 ml/min, the power density and the nitrate removal rate greatly increased to 34 W/m3 and 294 g NO3−-N/m3 d, respectively.

Hung-Thuan Tran, Dae-Hee Kim, Se-Jin Oh et al.

Water Science and Technology • 2009

Simultaneous organics removal and nitrification using a novel nitrifying biocathode microbial fuel cell (MFC) reactor were investigated in this study. Remarkably, the introduction of nitrifying biomass into the cathode chamber caused higher voltage outputs than that of MFC operated with the abiotic cathode. Results showed the maximum power density increased 18% when cathode was run under the biotic condition and fed by nitrifying medium with alkalinity/NH4+-N ratio of 8 (26 against 22 mW/m2). The voltage output was not differentiated when NH4+-N concentration was increased from 50 to 100 mg/L under such alkalinity/NH4+-N ratio. However, interestingly, the cell voltage rose significantly when the alkalinity/NH4+-N ratio was decreased to 6. Consequently, the maximum power density increased 68% in compared with the abiotic cathode MFC (37 against 22 mW/m2). Polarization curves demonstrated that both activation and concentration losses were lowered during the period of nitrifying biocathode operation. Ammonium was totally nitrified and mostly converted to nitrate in all cases of the biotic cathode conditions. High COD removal efficiency (98%) was achieved. In light of the results presented here, the application of nitrifying biocathode is not only able to integrate the nitrogen and carbon removal but also to enhance the power generation in MFC system. Our system can be suggested to open up a new feasible way for upgrading and retrofitting the existing wastewater treatment plant by the use of MFC-based technologies.

Mpumelelo Thomas Matsena, Shepherd Masimba Tichapondwa, Evans Martin Nkhalambayausi Chirwa

Catalysts • 2020

Palladium (Pd) is a cheap and effective electrocatalyst that is capable of replacing platinum (Pt) in various applications. However, the problem in using chemically synthesized Pd nanoparticles (PdNPs) is that they are mostly fabricated using toxic chemicals under severe conditions. In this study, we present a more environmentally-friendly process in fabricating biogenic Pd nanoparticles (Bio-PdNPs) using Citrobacter sp. isolated from wastewater sludge. Successful fabrication of Bio-PdNPs was achieved under anaerobic conditions at pH six and a temperature of 30 °C using sodium formate (HCOONa) as an electron donor. Citrobacter sp. showed biosorption capabilities with no enzymatic contribution to Pd(II) uptake during absence of HCOONa in both live and dead cells. Citrobacter sp. live cells also displayed high enzymatic contribution to the removal of Pd(II) by biological reduction. This was confirmed by Scanning Electron Microscope (SEM), Electron Dispersive Spectroscopy (EDS), and X-ray Diffraction (XRD) characterization, which revealed the presence Bio-PdNPs deposited on the bacterial cells. The bio-PdNPs successfully enhanced the anode performance of the Microbial Fuel Cell (MFC). The MFC with the highest Bio-PdNPs loading (4 mg Bio-PdNP/cm2) achieved a maximum power density of 539.3 mW/m3 (4.01 mW/m2) and peak voltage of 328.4 mV.

Ardiyan Harimawan, Hary Devianto, Rd. Habib R. M. T. Al-Aziz et al.

Journal of Engineering and Technological Sciences • 2019

Microbial fuel cell is one alternative technology that can be used to simultaneously solve problems related with wastewater production and energy demand. This study investigates the influence of electrode distance on power density in microbial fuel cell using tapioca wastewater. Graphite sheet without metal catalyst was used for both electrodes, separated by Nafion membranes. Four variations of electrode distance were used. MFC with highest electrode distance give the highest equilibrium OCV (676 mV), while the MFC with shortest electrode distance give the highest power density (7.74 mW/m2). EIS measurement suggested that the charge transfer resistance is dominant in all MFC configuration. Wastewater COD removal were in the range of 35-46 %, which were in accordance with the power density for all MFC.

Karanam Nithin, Vasupalli Manoj, Budumuru Mohith

INTERANTIONAL JOURNAL OF SCIENTIFIC RESEARCH IN ENGINEERING AND MANAGEMENT • 2023

A fuel-cell hybrid electric vehicle is an advanced type of hybrid vehicle that utilizes a combination of fuel-cell technology and electric propulsion for improved efficiency. The fuel cell generates electricity through a chemical reaction using hydrogen as the fuel source. This electricity powers the vehicle’s electric motor, while a battery system stores excess energy, provides additional power during acceleration, and stores regenerative braking energy. To improve the performance of fuel cell hybrids, designing and developing efficient energy management strategies is an urgent need for current automotive manufacturers. From the perspective of energy consumption, the main work is to reduce hydrogen consumption. In recent years, energy management strategies based on intelligent connected vehicle technology have also received extensive attention. Most fuel cell vehicles are classified as zero- emission vehicles that emit only water and heat. Compared with internal combustion vehicles, hydrogen vehicles centralize pollutants at the site of hydrogen production. In an electric drive vehicle, the low-voltage auxiliary battery provides electricity to start the engine before the traction battery is engaged, it also powers vehicle accessories. This high-voltage battery stores energy from regenerative braking and provides supplemental power to the electric motor. The DC converter converts higher voltage to lower voltage DC power which is needed to run the vehicle and recharge the auxiliary battery. Using power from the fuel cell and the traction battery pack, the motor drives the vehicle’s wheels. A fuel cell stack is an assembly of individual membrane electrodes that use hydrogen and oxygen to produce electricity. So the fuel cell electric vehicle is the best option to simultaneously reduce air pollution, greenhouse gas emissions, and the consumption of fossil fuels Key Words: Battery(auxiliary), Battery pack such as petroleum and natural gas., DC/DC Converter, Electric traction motor(FCEV), Fuel cell stack, Fuel filler, Fuel tank(hydrogen), Power electronics controller, Thermal system(cooling), Transmission(electric)

Tri Dewi Kusumaningrum Pribadi, Yudi Nurul Ihsan, Kalysta Fellatami et al.

Asian Journal of Water, Environment and Pollution • 2019

Cirata is one of the three reservoirs of Citarum where its function has developed from hydroelectric power generator to aquaculture and tourism in recent times. A number of floating net cage keeps increasing and they have reached 53,031 cages, which have actually exceeded the maximum amount under local government regulation. This condition has triggered eutrophication in the form of ammonium deposited in aquatic sediments. A study with a 30-day treatment of oxidation catalysis of inorganic and organic matter by bacteria called Microbial Fuel Cell (MFC) technology had been conducted to reduce contamination of ammonium in the water. Various treatments were applied in the form of single and dual chambers, with and without aeration. Parameters measurements were decreased in ammonium levels in the sediment, and the same applied to the electricity generated as the by-product of microbial activity. The results showed that MFC technology was proven to reduce the levels of ammonium in the sediments up to 96.12%. The electricity output reached 333 mA.m -2 for a single chamber treatment with aeration. Overall, it can be indicated that better results appeared in all measured parameters with single-chamber treatments compared to dual-chamber ones.