Mehroze Iqbal, Amel Benmouna, Frederic Claude et al.

Energies • 2023

Mainstream power-conditioning devices such as boost converters are frequently utilized for developing a compatible interface between a fuel cell, electrical storage, and high power loads. The conventional power stage comprising a unique boost converter suffers from low efficiency and poor reliability due to excessive power losses, particularly in high-power applications. Additionally, the presence of high ripple contents can reduce the lifespan of the fuel cell itself. With this background, this paper proposes and experimentally validates a physical components-assisted equivalent power-sharing strategy between parallel-coupled boost converters (PCCs) that is subjected to a wide spectrum of low-voltage–high-power conditions. The operation of PCCs is bottlenecked by several practical limitations, such as the presence of inner circulating currents (ICCs) and stability issues associated with the equivalent sharing of power. To overcome these limitations, a module of reverse blocking diodes is suggested to avoid ICCs between the PCCs. Further, an equalization filter is properly placed to improve the equivalent power-sharing capability. The proposed strategy is theoretically assessed in a MATLAB/Simulink environment with a 6 kW proton exchange membrane fuel cell (PEMFC) as the main power source. A scaled-down laboratory setup consisting of an 810 W PEMFC stack, an electronic load, three boost converters, and a filter circuit is then designed and critically evaluated. A consistent agreement is observed between the experimental findings and the simulation results under realistic operating conditions.

Aryama Raychaudhuri, Manaswini Behera

Research Square • 2021

Abstract An innovative design approach was employed in the present study to enhance the electricity generation and wastewater treatment in a microbial fuel cell (MFC). A dual-chambered MFC with a ceramic separator was coupled with an acidogenic chamber. Acidogenic bioconversion of rice mill wastewater into volatile fatty acid (VFA) represents an interesting approach for wastewater valorization. The VFA containing effluent could be used as an effective substrate for bioelectricity generation in MFCs. A short hydraulic retention time (HRT) can be used for the two-stage anaerobic process (acidogenesis and electrogenesis), thus preventing the proliferation of methanogens. The effect of pH (5.5–7.5) and HRT (0.5 d–0.75 d) were investigated to understand the influence of operational parameters on the performance of the integrated system. The maximum VFA concentration of 1065.15 ± 5.08 mg COD/L was achieved at pH 7.5 and HRT 0.5 d. Under these operating conditions, the general activity of acid-forming microorganisms and exoelectrogens improved remarkably, and the power density obtained from the system was 4.72 ± 0.10 W/m 3 . The current research indicates excellent potential for simultaneous treatment and electricity production from rice mill wastewater. The use of low-cost, locally manufactured, and customized membranes and the two-stage treatment can pave the way for the practical application of this technology.

Marzia Quaglio, Daniyal Ahmed, Giulia Massaglia et al.

Fuels • 2021

Sediment microbial fuel cells (SMFCs) are energy harvesting devices where the anode is buried inside marine sediment, while the cathode stays in an aerobic environment on the surface of the water. To apply this SCMFC as a power source, it is crucial to have an efficient power management system, leading to development of an effective energy harvesting technique suitable for such biological devices. In this work, we demonstrate an effective method to improve power extraction with SMFCs based on anodes alternation. We have altered the setup of a traditional SMFC to include two anodes working with the same cathode. This setup is compared with a traditional setup (control) and a setup that undergoes intermittent energy harvesting, establishing the improvement of energy collection using the anodes alternation technique. Control SMFC produced an average power density of 6.3 mW/m2 and SMFC operating intermittently produced 8.1 mW/m2. On the other hand, SMFC operating using the anodes alternation technique produced an average power density of 23.5 mW/m2. These results indicate the utility of the proposed anodes alternation method over both the control and intermittent energy harvesting techniques. The Anode Alternation can also be viewed as an advancement of the intermittent energy harvesting method.

Xuan Yang, Cong Li, Cheng Li et al.

New Journal of Chemistry • 2024

Through a one-step hydrothermal method, we synthesized CCS- M ( M = Cu/Co ratio) catalysts, with M = 0.5 showing optimal ORR performance. As an MFC cathode, it achieved 200.08 mW m −2 power density and stable 345 mV output.

I. A. Ieropoulos, J. You, I. Gajda et al.

Fuel Cells • 2018

Abstract Microbial fuel cells (MFCs) are energy transducers, which through the metabolic reactions of facultative anaerobic microorganisms, transform the energy in organic matter directly into electricity. Extrinsic parameters such as hydraulic retention time, fuel quality (type and concentration) and physicochemical environment of electrodes and biofilms (e.g., temperature, pH, salinity, and redox), can all influence system efficiency. This work proposes that MFCs can be “fine‐tuned” by adjustment of any of the physicochemical conditions including redox potential; in this context, an entirely novel method was investigated as a practical means of tuning, modulating and monitoring the redox potential within the electrode chambers. The method uses additional electrodes – known as 3 rd and 4 th ‐pins for anode and cathode chambers, respectively – which can be used in individual units, modules, cascades or stacks, for optimising the production of a large variety of chemicals, as well as biomass, water and power. The results have shown that the power output modulation resulted in an up to 79% and 33% increase, when connected via 3 rd and 4 th pins, respectively. Apart from power improvement, this study also demonstrated a method of open circuit potential (OCP) sensing, by using the same additional electrodes to both monitor and control the MFC signal in real time.

Pinkhas Rapaport, Yeh-Hung Lai, Chunxin Ji

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

This paper reports on the study of gas diffusion media (GDM) intrusion into reactant gas channels and its effect on the performance of the proton exchange membrane (PEM) fuel cell. The PEM fuel cell under consideration consists of a membrane electrode assembly (MEA) sandwiched between two layers of gas diffusion media commonly made of carbon paper or cloth. The GDM/MEA/GDM assembly is then compressed between two adjacent bi-polar plates. In this configuration, the compression pressure is transmitted under the lands of the reactant gas flow-field onto GDMs on which the portion over the channels remain unsupported. Because of the relatively low bending and compressive stiffness, it is found that GDMs can easily intrude into the reactant gas channels. The direct consequence of GDM intrusion is the pressure drop increase in the reactant gases in the intruded channels. This is further compounded by cell-to-cell or channel-to-channel variation in GDM thickness and mechanical properties, which results in non-uniform reactant gas flow distribution and ultimately negatively impacts the fuel cell performance. In this study, we have developed a GDM intrusion model based on the finite element method (FEM. We have also devised an experimental setup to measure the GDM intrusion, in which we found good agreement between the model prediction and experimental measurement. Combining the FEM based intrusion model and a flow redistribution model we have investigated the effect of GDM channel intrusion on the reactant flow distribution and the impact on the fuel cell performance. It is found that a 20% reduction of reactant flow can be induced with a 5% additional blockage in channels by GDM intrusion. Based on the findings from the current study, we attribute the significant performance variation in a 30-cell fuel cell stack to the variation in reactant flow induced by the variation in GDM intrusion. The results from the analytical study and fuel cell testing both suggested that the product variations in GDM would need to be significantly reduced and the stiffness of the GDM would need to be increased if the PEM fuel cells of high power density were to be used reliably at a relatively low stoichiometry.

Seok-Beom Yun, Youn-Jea Kim

Volume 6: Ceramics and Ceramic Composites; Coal, Biomass, Hydrogen, and Alternative Fuels; Microturbines, Turbochargers, and Small Turbomachines • 2021

Abstract Renewable energy such as hydrogen or solar energy is promising due to issues surrounding environmental pollution. In particular, hydrogen only produces water and generates electric energy in a fuel cell when reacting electrochemically with air. A fuel cell consists of many parts such as a cell stack, an ejector, a hydrogen tank, and a regulator, and so on. In this study, the ejector, a device that supplies hydrogen to proton exchange membrane fuel cell (PEMFC), is studied. The ejector recirculates unreacted hydrogen in proton exchange membrane fuel cells by the Venturi effect. Since the ejector is related to energy efficiency, many researchers have conducted research to improve the performance of the ejector. Therefore, it is most desirable that hydrogen recirculation in the ejector is increased. The present research investigates how the configuration of the ejector affects the hydrogen recirculation. A concave configuration of the ejector is considered. This concave having a helical pattern is dependent on a pitch ratio and the number of grooves. The results are compared with numerical analysis data from existing publications using computational fluid dynamics (CFD). The influence of the configuration was analyzed by performing numerical simulations with three-dimensional grid systems. A poly-hex-core mesh type was applied to reduce errors caused by convection and diffusion in the computational domain. Considering the configurations of the ejector, turbulence dissipation rate, static pressure, and tangential velocity inflow were analyzed graphically. Consequently, it was determined that the model displays a 7% increase in recirculation ratio over the reference model.

Mahak Jain, Partha Sarathi Ghosal, Ashok Kumar Gupta

• 2023

In recent times, the research trend has shifted towards identifying sustainable energy resources. Bioenergy generation employing wastewater and micro-organisms might be a potential solution to achieve this goal. In microbial fuel cells (MFC), the energy stored in the chemical bonds of contaminants present in wastewater is utilized by the micro-organisms for their metabolism in redox conditions. Furthermore, in this process, free electrons are released into the system, which are captured by the electrodes resulting in the generation of electricity in the external circuit. Hence, the system provides wastewater treatment along with bioenergy generation. However, the system finds difficulty in degrading recalcitrant organic compounds, such as pharmaceuticals and other emerging contaminants, which is possible in constructed wetland (CW) systems. However, CWs require a large footprint area. Recently, combined CW and MFC systems are being used for this purpose due to their resilience and capacity to produce electricity and provide a high level of wastewater treatment. Combined CW-MFC has been found to be more useful than either system alone by complimenting their issues as the redox conditions required for the proper functioning of the MFC system are available in the CW system. Furthermore, the high diversity of micro-organisms present in MFC improves the treatment efficiency of the CW system. This study involves the application of a combined CW-MFC system for the treatment of wastewater and the production of bioelectricity using Lemna minor as macrophyte species. Graphite plates were used as the anode and cathode for electricity production. In order to test the system's effectiveness in terms of removing recalcitrant organic compounds, synthetic wastewater was spiked with 5 mg/L of sulfamethoxazole. The influence of various parameters, such as electrode spacing, the substrate to water depth ratio, and the initial COD concentration of wastewater, was studied. Considerably high removal of around 99% for sulfamethoxazole and 90% for COD removal were observed, along with the production of 133 mV of voltage. It was observed that with the increase in initial COD concentration and substrate to water depth ratio, COD removal also increased. However, an increase in electrode spacing and substrate to water depth ratio after a certain limit showed a negative effect on voltage generation. The entire system could effectively generate bioenergy and treat the sulfamethoxazole-contaminated wastewater.Keywords- Constructed wetlands, Microbial fuel cell, Lemna minor, Emerging contaminants, Bioelectricity

Md. Abdul Halim, Md. Owaleur Rahman, Mohammad Ibrahim et al.

Journal of Chemistry • 2021

Finding sustainable alternative energy resources and treating wastewater are the two most important issues that need to be solved. Microbial fuel cell (MFC) technology has demonstrated a tremendous potential in bioelectricity generation with wastewater treatment. Since wastewater can be used as a source of electrolyte for the MFC, the salient point of this study was to investigate the effect of pH on bioelectricity production using various biomass feed (wastewater and river water) as the anolyte in a dual-chambered MFC. Maximum extents of power density (1459.02 mW·m−2), current density (1288.9 mA·m−2), and voltage (1132 mV) were obtained at pH 8 by using Bhairab river water as a feedstock in the MFC. A substantial extent of chemical oxygen demand (COD) removal (94%) as well as coulombic efficiency (41.7%) was also achieved in the same chamber at pH 8. The overall performance of the MFC, in terms of bioelectricity generation, COD removal, and coulombic efficiency, indicates a plausible utilization of the MFC for wastewater treatment as well as bioelectricity production.

Ademola Adekunle, Vijaya Raghavan

Waste Management & Research: The Journal for a Sustainable Circular Economy • 2016

In a number of energy-poor nations, peel from cassava processing represents one of the most abundant sources of lignocellulosic biomass. This peel is mostly discarded indiscriminately and eventually constitutes a problem to the environment. However, energy can be extracted from this peel in a microbial fuel cell. In this study, the viability of cassava peel extract as a substrate in a single-chamber air cathode microbial fuel cell is demonstrated, and optimum performance conditions are explored. The effects of different pretreatments on the extract are also discussed in the context of observed changes in the internal resistances, conductivity and Coulombic efficiencies. At the best conditions examined, the extract from cassava peel fermented for 168 h and adjusted to a pH of 7.63 attained a peak voltage of 687 mV ± 21 mV, a power density of 155 mW m −3 of reactor volume and a Coulombic efficiency of 11 %. Although this energy is limited to direct use, systems exist that can effectively harvest and boost the energy to levels sufficient for supplementary energy usage in cassava producing regions.

Rachel C Wagner, Sikandar Porter-Gill, Bruce E Logan

AMB Express • 2012

Abstract Current-generating (exoelectrogenic) bacteria in bioelectrochemical systems (BESs) may not be culturable using standard in vitro agar-plating techniques, making isolation of new microbes a challenge. More in vivo like conditions are needed where bacteria can be grown and directly isolated on an electrode. While colonies can be developed from single cells on an electrode, the cells must be immobilized after being placed on the surface. Here we present a proof-of-concept immobilization approach that allows exoelectrogenic activity of cells on an electrode based on applying a layer of latex to hold bacteria on surfaces. The effectiveness of this procedure to immobilize particles was first demonstrated using fluorescent microspheres as bacterial analogs. The latex coating was then shown to not substantially affect the exoelectrogenic activity of well-developed anode biofilms in two different systems. A single layer of airbrushed coating did not reduce the voltage produced by a biofilm in a microbial fuel cell (MFC), and more easily applied dip-and-blot coating reduced voltage by only 11% in a microbial electrolysis cell (MEC). This latex immobilization procedure will enable future testing of single cells for exoelectrogenic activity on electrodes in BESs.

V. Mounica, Y. P. Obulesu

Energies • 2022

The power management strategy (PMS) is intimately linked to the fuel economy in the hybrid electric vehicle (HEV). In this paper, a hybrid power management scheme is proposed; it consists of an adaptive neuro-fuzzy inference method (ANFIS) and the equivalent consumption minimization technique (ECMS). Artificial intelligence (AI) is a key development for managing power among various energy sources. The hybrid power supply is an eco-acceptable system that includes a proton exchange membrane fuel cell (PEMFC) as a primary source and a battery bank and ultracapacitor as electric storage systems. The Haar wavelet transform method is used to calculate the stress σ on each energy source. The proposed model is developed in MATLAB/Simulink software. The simulation results show that the proposed scheme meets the power demand of a typical driving cycle, i.e., Highway Fuel Economy Test Cycle (HWFET) and Worldwide Harmonized Light Vehicles Test Procedures (WLTP—Class 3), for testing the vehicle performance, and assessment has been carried out for various PMS based on the consumption of hydrogen, overall efficiency, state of charge of ultracapacitors and batteries, stress on hybrid sources and stability of the DC bus. By combining ANFIS and ECMS, the consumption of hydrogen is minimized by 8.7% compared to the proportional integral (PI), state machine control (SMC), frequency decoupling fuzzy logic control (FDFLC), equivalent consumption minimization strategy (ECMS) and external energy minimization strategy (EEMS).

J.C. Carrillo-Rodriguez, I.L Alonso-Lemus, R. Pérez-Hernández et al.

ECS Meeting Abstracts • 2017

Nanostructured Pd-CeO 2-NR /G, synthesized with NaBH 4 as reducing agent, was evaluated as cathode catalyst for the Oxygen Reduction Reaction (ORR) in 0.5 M KOH and in a Microbial Fuel Cell (MFC) with pH=9.6. Previously, ceria nanorods (CeO 2-NR ) were synthesized by a hydrothermal method, while graphene (G) was obtained by mechanical milling. Morphological characterization showed agglomerated Pd nanoparticles and CeO 2-NR dispersed over graphene. Evaluation of catalytic activity for the ORR in half cell showed a higher mass activity of Pd-CeO 2-NR /G relative to Pd/C. The MFC was of the two-chamber type, separated by a Nafion(R) 117 membrane. In the anode, residual water directly from a pharmaceutical company (pH=9.6) was the electrolyte with an anode containing commercial Pt/C. The Bacilus Subtilis microorganism was used to form a biofilm over Pt/C and promote the bioelectrochemical reactions in N 2 atmosphere. In the cathode chamber, KOH with pH=9.6 was the electrolyte, which was saturated with O 2 . The polarization curves from the MFC demonstrated a higher catalytic activity of Pd-CeO 2-NR /G than Pd/C. The former delivered an open circuit voltage of 0.26 V and a maximum power density of 12.47 mW m -2 .

Yueping Ren, Danyun Pan, Xiufen Li et al.

Journal of Chemical Technology & Biotechnology • 2013

Abstract BACKGROUND The limitation on output power is a great challenge for the practical application of sediment microbial fuel cells ( SMFC ). One of the effective strategies to overcome this problem is to develop better‐performing cathodes . RESULTS Polyaniline (PANI)‐graphene nanosheets (GNS) modified cathodes were fabricated and applied as the cathodes of SMFCs to improve their electricity generation capacity. PANI‐GNS cathodes were fabricated through situ‐polymerization of aniline in a solution containing homogeneously dispersed GNS . The mass ratio between aniline and GNS in the polymerized solution was the key factor controlling the properties of the modified cathode and the optimum ratio was 9:1. Because of the outstanding electrical conductivity of GNS , PANI‐GNS cathodes outperform the control (blank) and PANI cathodes. The PANI‐GNS 0 .1 ‐ SMFC exhibited the highest output voltage of 640 mV , 5 times that of the blank SMFC ; the maximum power density was improved from 0.85 mW m ‐2 with the blank SMFC to 99 mW m ‐2 of the optimal PANI‐GNS 0 .1 ‐ SMFC . CONCLUSIONS This study provides a simple electrode modifying method to enable an as‐synthesized PANI‐GNS cathode to dramatically promote the performance of an SMFC . © 2013 Society of Chemical Industry

S. A. Abbasi, Tabassum Abbasi, Pratiksha Patnaik

Nature Environment and Pollution Technology • 2021

Studies are presented in the context of the past attempts at finding nanocatalysts that can boost the performance of microbial fuel cells (MFCs) ? in terms of waste treatment and energy generation. Given the great potential of biomimetically synthesized nanoparticles (BMNPs) in providing less expensive and more environmentally friendly alternatives to NPs synthesized by physical and chemical methods, as well as a near-total lack of previous work in this area, the current research was undertaken. Effect of gold and silver nanoparticles (NPs), synthesized biomimetically using five freely available weeds, was assessed as catalysts in the MFCs. In all cases, the nanoparticles were seen to enhance the coulombic efficiency (reflective of the reduction in the waste’s organic carbon load), maximum attainable power density, and overall energy yield of the MFCs by >200% relative to the uncatalyzed MFCs. Gold nanoparticles were more effective than silver nanoparticles by ? 20%. The results reveal that biomimetically synthesized NPs can be highly effective in reducing the operational costs as well as ecological footprints of MFCs and further work should be focused on NPs of non-precious metals.

Rishi Gurjar, Manaswini Behera

Fermentation • 2022

Performance evaluation of a ceramic microbial fuel cell (CMFC) by varying organic strength, hydraulic retention time (HRT) and anode electrode surface area (AESA) to treat leachate generated from acidogenesis of kitchen waste (KW) was studied by the central composite design of experiment. The increase in organic loading rate (OLR) positively affected power density (PD) while negatively influencing organic removal and coulombic efficiency (CE). This behavior is possible due to substrate inhibition and the coercive effect of low HRT, i.e., substrate washout, biofilm abrasion, and reduced contact period, while at high HRT, the volatile fatty acid (VFA) degradation improved. Since acetic acid is the final product of long-chain VFAs degradation, a pseudo consumption order for VFAs was obtained: butyric > propionic > acetic. The AESA aided organics removal and PD but had a negligible effect on CE. According to ANOVA, the COD removal was linearly modeled, while PD and CE were quadratic. The validation runs (VR) proved efficient as the highest COD removal was for VR2 (83.7 ± 3.6%), while maximum PD and CE values obtained were 0.224 ± 0.02 W/m3 and 2.62 ± 0.33%, respectively, for VR3, supported by the lower anode potential.

Iliya Krastev Iliev, Antonina Andreevna Filimonova, Andrey Alexandrovich Chichirov et al.

Energies • 2024

Currently, the process of creating industrial installations is associated with digital technologies and must involve the stage of developing digital models. It is also necessary to combine installations with different properties, functions, and operational principles into a single system. Some tasks require the use of predictive modeling and the creation of “digital twins”. The main processes during the fuel cell modeling involve electrochemical transformations as well as the movement of heat and mass flows, including monitoring and control processes. Numerical methods are utilized in addressing various challenges related to fuel cells, such as electrochemical modeling, collector design, performance evaluation, electrode microstructure impact, thermal stress analysis, and the innovation of structural components and materials. A digital model of the membrane-electrode unit for a solid oxide fuel cell (SOFC) is presented in the article, incorporating factors like fluid dynamics, mass transfer, and electrochemical and thermal effects within the cell structure. The mathematical model encompasses equations for momentum, mass, mode, heat and charge transfer, and electrochemical and reforming reactions. Experimental data validates the model, with a computational mesh of 55 million cells ensuring numerical stability and simulation capability. Detailed insights on chemical flow distribution, temperature, current density, and more are unveiled. Through a numerical model, the influence of various fuel types on SOFC efficiency was explored, highlighting the promising performance of petrochemical production waste as a high-efficiency, low-reagent consumption fuel with a superior fuel utilization factor. The recommended voltage range is 0.6–0.7 V, with operating temperatures of 900–1300 K to reduce temperature stresses on the cell when using synthesis gas from petrochemical waste. The molar ratio of supplied air to fuel is 6.74 when operating on synthesis gas. With these parameters, the utilization rate of methane is 0.36, carbon monoxide CO is 0.4, and hydrogen is 0.43, respectively. The molar ratio of water to synthesis gas is 2.0. These results provide an opportunity to achieve electrical efficiency of the fuel cell of 49.8% and a thermal power of 54.6 W when using synthesis gas as fuel. It was demonstrated that a high-temperature fuel cell can provide consumers with heat and electricity using fuel from waste from petrochemical production.

Fumihiko Yoshiba

Journal of Fuel Cell Science and Technology • 2008

A module part of a 7MW class centralized molten carbonate fuel cell/gas turbine (GT) combined system has been tested. Since the designed (GT) working pressure is 1.2MPa, the operating pressure of the module was high (1.2MPa). In order to realize a high steam-reforming efficiency of the fuel gas under high-pressure operation, the module has an additional adiabatic reformer, which changes the CH4 remaining in the exhausted anode gas to H2. Using a 125-cell stack, the module was operated and the performance of the stack was evaluated; the CO2 partial pressure of the cathode inlet gas was kept low during the operation. The maximum operating current density of the stack was limited to 1600A∕m2; however, the maximum total steam-reforming efficiency of the fuel gas was 96% in the module. The heat loss of the module was evaluated in the pressure swing test. Using these operation results, the efficiency of the module, at the designed operating current density of 2000A∕m2, was estimated; the result was 39.6% low heating value (LHV) by applying the normal cell performance, whereas 44.4% LHV by applying the best performance cell. The module efficiency of 44.4% LHV corresponds to the system’s net efficiency of 48% high heating value in the 7MW system.

Willie Prasidha, Akmal Irfan Majid

Jurnal Penelitian Saintek • 2020

This study was aimed at evaluating the performance of non-aerated and aerated double chamber microbial fuel cells from food waste leachate. The value of open circuit voltage (OCV) and close circuit voltage (CCV) were taken to analyze power density and current density of both configurations. Two double chamber microbial fuel cells (MFC) with different configurations were developed to produce electricity from food waste leachate and studied for 30 days. Anode and catode were made by uncoated carbon felt and graphite rod. Food waste and water were incubated inside a reactor. After 30 days, the electricity production characteristics between the two configurations were obtained. Both configurations reached the same maximum power density and maximum current density but the aerated MFC showed higher performance of maximum open-circuit voltage (OCV), average power density, and current density than non-aerated MFC. The results show that the supplying continuous dissolved air in the cathode chamber resulted in higher voltage, higher average power density, and higher average current density in double chamber microbial fuel cell.

Seyed Hesam‐Aldin Samaei, Gholamreza Bakeri, Mohammad Soleimani Lashkenari

Journal of Applied Polymer Science • 2020

Abstract In this research, the preparation of low cost proton exchange membranes (PEMs) based on sulfonated poly ether ether ketone (SPEEK) for application in the microbial fuel cells (MFCs) is studied. Sulfonated polystyrene (SPS) and phosphotungstic acid (PWA) were employed to improve the performance of PEM through the creation of more proton pathways. At first, the sulfonation of PEEK and polystyrene were performed through two modified methods to obtain uniform and high degree of sulfonation (DS) of the polymers and then, the PEMs were prepared through the solution casting method. Accordingly, the formation of uniform skin layer was confirmed by the SEM micrographs. Blending the aforementioned additives to the SPEEK polymer solution significantly enhanced the proton conductivity, water uptake and durability of the modified membranes. The proton conductivities of SPEEK/SPS and SPEEK/PWA membranes at additive/SPEEK weight ratio of 0.15 were 45.3% and 26.2% higher than that of the commercial Nafion117 membrane, respectively. Moreover, the degradation times for the abovementioned modified membranes were 140 and 350 min which indicated satisfactory oxidation stability. Besides, the aforementioned membranes exhibited two times more water uptake compared to the neat SPEEK membrane. Finally, SPEEK/SPS and SPEEK/PWA membranes produced 68% and 36% higher maximum power in the MFC, compared to the commercial Nafion117 membrane. Therefore, the fabricated PEMs are potentially suitable alternatives to be used in the fuel cell applications.

Hao-Ming Chang, Min-Hsing Chang

Journal of Fuel Cell Science and Technology • 2013

In this study, the performance of a polymer electrolyte membrane fuel cell with double-side microporous layer (MPL) coating on gas diffusion layer (GDL) is investigated experimentally. A standard commercial SGL® 10BA carbon paper is used as the substrate and it is coated with MPL on both sides of the paper with different composition. Three different carbon powders are used in the experiments, including Vulcan XC-72R, Acetylene black, and Black Pearls 2000. The effect of polytetrafluoroethylene (PTFE) content is also considered. A single cell testing apparatus is constructed to measure the cell performance and evaluate the effect of GDL with double-side MPL coating. Accordingly, the optimal fabrication parameters of double-side MPL are determined. The result shows that under the same operating conditions, the performance of fuel cell using GDL with double-side MPL is better than that using general single-side MPL. The Acetylene black is found to give the best cell performance than the others. The optimal composition of MPL on the surfaces facing to the catalyst layer and flow-channel plate are 1.25 mg/cm2 and 0.25 mg/cm2, respectively. Besides, the optimal PTFE content is the same on both sides of MPL which is found to be 20 wt%.

Susanta K. Das, K. J. Berry

ASME 2016 14th International Conference on Fuel Cell Science, Engineering and Technology • 2016

In this paper, using patented nano-additive based polymer synthesis technology, a novel approach to the design and fabrication of high temperature proton exchange membrane (PEM) has been developed. The presence of sulfonated octaphenyl POSS (S-POSS) in a PBI-PA (polybenzimidazole-phosphoric acid) membrane results in a 40–50% increase in conductivity at 120–200$deg relative to non-sulfonated silica or POSS control fillers at comparable weight percent filler loadings and PBI molecular masses, and also relative to unfilled PBI-PA membranes. In addition, the presence of S-POSS and silica both result in physical reinforcement of the membrane and increased its modulus and mechanical integrity, but only S-POSS offers the benefits of both increased conductivity and increased modulus. Isophthalic acid and 3,3’-diaminobenzidine (DAB) were polymerized in the presence of polyphosphoric acid (PPA) and S-POSS nanoadditive, and the degree of polymerization was monitored by viscosity and torque change measurements. Molecular mass was determined by inherent viscosity measurements of samples removed from the reaction solution. Membranes were prepared by casting the reaction solution and allowing PPA to hydrolyze to PA under ambient conditions. The membranes were characterized for acid content, in-plane conductivity, tensile modulus and shear modulus, and were roll-milled to achieve the desired thickness for membrane electrode assembly (MEA) fabrication.

M Amirul Islam

IIUM Engineering Journal • 2017

Microbial fuel cell (MFC) is a bioelectrochemical system that uses bacteria as biocatalyst to oxidize organic substrates as well as release electrons, which can be harvested in an external circuit to produce electrical energy. In this study, a proteolytic biocatalyst Bacillus cereus (B. cereus) has been employed for the first time in a microbial fuel cell (MFC). The wild type pure culture was isolated from municipal wastewater and identified using Biolog Gen III analysis. The MFCs were fueled with palm oil mill effluent (POME) and attained the maximum power density of about 3.88 W/m3. The electrochemical behavior of MFC operated by B. cereus was evaluated using polarization curve, electrochemical impedance spectroscopy (EIS) and cyclic voltammetery (CV) analysis. B. Cereus excreated electron shuttling compound which significantly reduced the anode charge transfer resistance (52.95%). The FESEM result shows that B. Cereus has the capability of effective biofilm formation. These results revealed the electrocatalytic potentiality of B. cereus and which makes it a promising candidate to be used in MFCs. Therfore, this biocatlyst can be used to generate electricity through the wastewater valorization.

Hong Song, Wei Guo, Menglin Liu et al.

Water Science and Technology • 2013

The microbial fuel cells (MFCs) are the focus of extensive investigation as one of the promising technologies for renewable energy generation and wastewater treatment. Two-chambered MFCs were designed to investigate the removal of metronidazole and to quantify the effect of antibiotic on the efficacy of energy generation. Using 1,000 mg glucose L−1 containing different concentrations of metronidazole (0, 10, 30, 50 mg L−1) as the fuels, the corresponding power densities were 141.94, 99.23, 25.44, 16.26 mW m−2, respectively. The adverse effect on the performance of the MFCs was reversible. The removal of metronidazole achieved 85.4% within 24 hours in MFCs, while only 35.2% in open circuit. Current generation could account for the improved removal efficiency at these tested concentration levels. The findings of this paper indicated that antibiotics such as metronidazole could be removed in MFCs, which has implications for general wastewater treatment.

Jakub Dziegielowski, Mirella Di Lorenzo

E3S Web of Conferences • 2021

Soil microbial fuel cell (SMFC) is a carbon-neutral energy harvesting technology that exploits the use of electroactive bacteria naturally present in soil to directly generate electricity from organic compounds. Given the simplicity of the system design, SMFCs have great potential to be used for decentralised solutions, especially in areas where access to conventional energy sources is limited. Yet, the high cost to power ratio severely limits the translation of this technology into the market. With the aim of reducing the capital cost, in this study we explore the effect of decreasing the amounts of current collector (CC) on the performance. The results demonstrate that increasing the amount of current collector per surface area of the electrode is not a feasible way of enhancing power densities, as to increase the performance by 20% and 35%, the amount of current collector would have to be increased by 150% and 300%, respectively. This highlights the importance of economic evaluations when optimising the design of a SMFC.

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Biointerface Research in Applied Chemistry • 2021

Hospital waste is a type of hazardous waste that contains a wide range of dangerous substances, including radioactive materials. Radiation-tolerant microbes have shown an interest in treating this liquid waste. Radiation-resistant microorganisms were chosen from irradiated fermented sausage in this investigation. The activity of enzymes such as protease, lipase, and laccase was studied. For hospital wastewater treatment, a single chamber microbial fuel cell (sMFC) with a radiation-tolerant bacterial consortium was deployed. The microbial structure analysis showed the selected consortium was similar to Acinetobacter sp. The COD was removed at a rate of 90.10±0.30%, and the power density (PD) was 168.91±3.89 mW/m2. This was the first study to use the radiation-resistant Acinetobacter sp. bacterial consortia to treat hospital waste and generate power simultaneously.

Julian Ferdinand, Adhi Yuniarto

Sainteknol : Jurnal Sains dan Teknologi • 2024

Chromium ions is notably a hazardous heavy metal due to its toxic and carcinogenic nature, particularly in its hexavalent form, Cr(VI). One of the major Cr(VI) pollution source is from electroplating industry effluent, which may contain high concentrations that pose a risk of contamination of aquatic and soil ecosystems if not treated carefully. One of the alternative method known to be able to treat Cr(VI) wastewater is by using microbial fuel cell (MFC). This research focused on on the removal of Cr(VI) from synthetic electroplating wastewater using a 4L dual-chamber MFC under fed-batch condition, as well as investigating the impact of mixed liquor suspended solids (MLSS) and chemical oxygen demand (COD) concentrations to its performance. Observed parameters include the efficiency of Cr(VI) removal and power density. Septage sludge and acetate were both used as biomass and substrate source respectively. Based on this research, it can be concluded that the highest Cr(VI) removal efficiency and power density were achieved using specific MLSS and COD concentration that resulting in F/M ratio of 0,459 to 0,489 gCOD/gMLSS. From initial Cr(VI) concentration of 50 mg/L, the highest removal was obtained by MFC running with initial MLSS and COD concentrations of 3.500 and 1.500 mg/L respectively, achieving 62,17% over 312 hours. This setup also produced the highest power density of 48,22 mW/m².

M N I M Sabri, N A Shamsuddin, M F A Alias et al.

IOP Conference Series: Earth and Environmental Science • 2021

Abstract Water and energy security are gaining high interest of many researchers and intensive exploration took place around the global. Membrane-less microbial fuel cell (ML-MFC) has been emerging as one of the popular wastewater treatment-based technology to provide clean water and green energy. MFC are bio-electrical devices that harness the natural metabolism of electrogenic bacteria (EB) to produce electrical energy. In this study, Bacillus subtilis (BS) was used to catalyst the transformation of carbon source in dewatered sludge into renewable energy. From the study, the MFCs were tested to see the robustness of the MFC by exposing them to the ambient temperature (25± 1°C) with the parameter of pH (6), electrode distance (6 cm), initial moisture content (30 % vol/wt) were set as constant. The result focused on the performance of the ML-MFC during noon (8-10 am and 4-6 pm) as these were the periods which BS recorded actively growth (increment of ±5.167 × 10 -3 mg/L of biomass per day). The ML-MFCs were carried out for 7 days incubation period and the BS growth reflected significantly on the voltage and power generated. The highest voltage and power density were recorded which were 90 mV and 8.793Watt/m 2 (at morning on 6th day), respectively. Moreover, observation gram staining of BS under a light microscope indicated a purple appearance due to thick peptidoglycan layer of the cell wall. Obviously, this study could be the bench mark of the practicality of the MFC technology which projected to be implemented in remote area where the natural environment condition is the surrounding parameter of the MFC same like in current study.

Tsvetomila Ivanova Parvanova-Mancheva, Elena Razkazova-Velkova, Martin Martinov et al.

Food Science and Applied Biotechnology • 2018

Traditional methods for wastewater treatment are associated with high energy consumption. This is why biological treatment of water is more appropriate at the moment. In our previous study, oxidation and reduction of pollutants have been proposed to be carried out in a microbial fuel cell (MFC) designed by our laboratory that simultaneously purifies wastewater from sulfide and nitrate ions and generates electricity. The experiments were carried out with two types of electrodes, graphite rods and paddling of activated carbon using a Fumapem® FFA-3-PK-75 (OH- form) membrane. The results show that the cell has higher energy output when using paddling of activated carbon as an electrode.

Víctor Salgado‐Dávalos, Sthefany Osorio‐Avilés, Sathish Kumar Kamaraj et al.

CLEAN – Soil, Air, Water • 2021

Abstract An economic and simple sediment microbial fuel cell (SMFC) design is evaluated to improve the recovery of energy from a river sediment, in terms of power density output (maximum power pick) normalized to the cathode surface. The organic matter content in the sediment is boosted by adding abundant, natural, and waste biomass (chitin) near the anode surface. The sluggish kinetics in the two‐electron reduction reaction of O 2 at the C‐cathode is replaced with an efficient four‐electron reduction reaction at the MnO 2 /C cathode. Five SMFCs composed of a common carbon fabric (CF) cathode and different unmodified anode materials, such as reticulate vitreous carbon (RVC: 10, 30, and 60 pore per inch, ppi), CF and commercial stainless‐steel (SS) mesh, are evaluated. The catholyte conductivity improved with Na 2 SO 4 . The results show that the power density output increased a 100‐fold when an MnO 2 /CF‐cathode is used with Na 2 SO 4 catholyte and the anolyte contained chitin. A microbial analysis of the SMFC sediment is performed. The bacterial groups identified, mainly Aminicenantia and Deltaproteobacteria , offer metabolic capacities to participate in the degradation of organic matter in the presence of chitin. Therefore, bacterial groups enriched in the anode biofilm produce electrical energy.

Xin Wang, Yujie Feng, Jia Liu et al.

Journal of Chemical Technology & Biotechnology • 2011

Abstract BACKGROUND: For a microbial fuel cell (MFC), the anode potential is an important electrochemical parameter for the growth, electron distribution and electrical activity of exoelectrogenic bacteria. RESULTS: The performance of a batch‐flow two‐chambered MFC was investigated operated at anode potentials of − 400, − 200, 0, + 200 and + 400 mV versus Ag/AgCl reference electrode. Glucose was used as substrate and ferricyanide as cathodic electron acceptor. At potentials from − 400 to + 200 mV, increasing maximum current outputs were obtained, ranging from 6.0 to 8.6 mA. However, the maximum current output decreased to 6.9 mA when the anode potential was further increased to + 400 mV. More positive potentials resulted in higher Coulombic efficiencies (CEs), with values increased from 64% (−400 mV) to 88% (+400 mV). Electrons deposited as H 2 and CH 4 resulted in lower CEs at more negative potentials (−400, − 200 and 0 mV). When + 400 mV was applied to the anode, the growth yield dropped from 0.25 ± 0.05 to 0.11 mol biomass mol −1 COD (chemical oxygen demand) with inhibition of electrical activity. CONCLUSIONS: The most positive anode potential reduced growth yield and inhibited bacterial growth, but electrical activity increased for potentials ranged from − 400 to + 200 mV. When the potential was increased to + 400 mV, growth yield was limited, affecting MFC performance. Copyright © 2011 Society of Chemical Industry

Sema Aslan, Peter Ó Conghaile, Dónal Leech et al.

Electroanalysis • 2017

Abstract Gluconobacter oxydans ( G. oxydans ) cells together with an osmium redox polymer (ORP) [Osmium (2,2’‐bipyridine)2(poly‐vinylimidazole)10Cl]Cl were combined with a glassy carbon paste electrode (GCPE) to form a bioanode for a microbial fuel cell (MFC) based on G. oxydans . Although there are G.oxydans / ORP combined bioanode in the literature, as far as it is known, this system is the first one where G.oxydans /ORP bioanode is combined with a cathode and a MFC is formed. After the optimization of experimental parameters, analytical characteristics of ORP/ G. oxydans /GCPE bioanode were investigated. ORP/ G. oxydans /GCPE showed two linear ranges for ethanol substrate as 1.0–30 mM (R 2 =0.902) and 30–500 mM (R 2 =0.997) and analytical range as 1.0–1000 mM. Limit of detection (3.0 s/m) and limit of quantification (10 s/m) values were calculated as 1.29 mM and 4.30 mM respectively where the RSD value was 1.16 % for n=5. Combining the developed bioanode in the presence of 5.0 mM K 3 Fe(CN) 6 mediator with a Pt wire cathode a double compartment MFC was obtained via a salt bridge. G. oxydans /GCPE bioanode based MFC had maximum power density of 0.133 μW cm −2 (at 33.5 mV), maximum current density as 8.73 μA cm −2 and OCP value of 156 mV. On the other hand, ORP/ G. oxydans /GCPE based MFC showed maximum power density as 0.26 μW cm −2 (at 46.8 mV), maximum current density as 15.079 μA cm ‐2 and OCP value of 176 mV.

Mohit Kumar, Soumya Pandit, Vinay Patel et al.

bioRxiv (Cold Spring Harbor Laboratory) • 2022

Abstract Utilization of organic wastewater for hydrogen production has dual advantages of clean energy generation and bioremediation which is sustainable for a longer period. To maximize the energy recovery from starch rich wastewater, a two stage system comprising of thermophilic dark fermentation coupled with microbial fuel cell was employed. A single parameter optimization strategy was implemented for the operation of the batch system. The maximum cumulative hydrogen production obtained was 2.56 L L −1 with a 48 % reduction in COD under the optimal conditions of 35 g L −1 initial substrate concentration (COD), temperature 60 o C, and pH 6.5. The H 2 yield and H 2 production rate were 6.8 mol H 2 /kg COD reduced and 731.3 mL L −1 h −1 respectively. The effect of the organic loading rate (OLR) on H 2 production rate was studied in a continuous stirred tank reactor (CSTR). A maximum hydrogen production rate of 913 mL L −1 h −1 was observed at an OLR of 5.6 g L − 1 h −1 . Effluent recycle played an important role in the improvement of H 2 production. A maximum H 2 production rate of 1224 mL L −1 h −1 was observed at a recycle ratio of 0.6. Power density of 4.2 W m −3 was observed with MFC using the dark fermentative spent media neutralized with carbonate buffer at an optimal pH of 7. A total COD reduction of 86% was observed.

Segundo Rojas-Flores, Renny Nazario-Naveda, Santiago M. Benites et al.

Molecules • 2022

The excessive use of fossil sources for the generation of electrical energy and the increase in different organic wastes have caused great damage to the environment; these problems have promoted new ways of generating electricity in an eco-friendly manner using organic waste. In this sense, this research uses single-chamber microbial fuel cells with zinc and copper as electrodes and pineapple waste as fuel (substrate). Current and voltage peaks of 4.95667 ± 0.54775 mA and 0.99 ± 0.03 V were generated on days 16 and 20, respectively, with the substrate operating at an acid pH of 5.21 ± 0.18 and an electrical conductivity of 145.16 ± 9.86 mS/cm at two degrees Brix. Thus, it was also found that the internal resistance of the cells was 865.845 ± 4.726 Ω, and a maximum power density of 513.99 ± 6.54 mW/m2 was generated at a current density of 6.123 A/m2, and the final FTIR spectrum showed a clear decrease in the initial transmittance peaks. Finally, from the biofilm formed on the anodic electrode, it was possible to molecularly identify the yeast Wickerhamomyces anomalus with 99.82% accuracy. In this way, this research provides a method that companies exporting and importing this fruit may use to generate electrical energy from its waste.

Emilio Steven Corrales Navarro*, Melissa May Muñoz Boado

Research Square • 2023

Abstract The rapid consumption of fossil fuels has led to calls to switch from non-renewable to renewable energy sources. Microbial fuel cells are a promising technology that simultaneously treats wastewater and produces power. This study used the Taguchi Experimental method to optimize anode thickness and pH to obtain the maximum power density of an air-cathode microbial fuel cell (ACMFC). The graphene-sponge (G-S) anode thickness and chamber pH were selected as operating parameters, with their corresponding levels. The L 9 orthogonal array was selected for the experimental design. According to Taguchi Method, the optimum G-S anode thickness and chamber pH were obtained at 1.0 cm and 8.0, respectively. A confirmatory run was performed with the optimum conditions, and accordingly, maximum power density was observed at 707.75 mW·m −3 . Analysis of variance (ANOVA) was conducted to identify the percentage contributions of operating parameters in the process and was found to be 30.66% for pH and 69.34% for anode thickness.

Atit Jawre, Priyanshi Chauhan, Anket Patel et al.

Preprints.org • 2019

In these times electricity is big trouble of problem facing by the world. Therefore, there is necessitating for the property basis of energy that is employed for as bio-electricity. Many of the scientists and researchers are trying to find out the sustainable energy generates with the help of plant microbial fuel cell. Plant microbial fuel cell (P-MFCs) could be feasibility technology approach of bio-electricity generation which is mutualism interaction of the plants along with their rhizospheric bacteria. In the present study, Plant-microbial fuel cell was observed in grass e-table evaluated in term of bioelectricity generation from Cynodon dactylon (Dooba Ghas). This e-table was connected with electrode and different condition (physical and chemical) to detect the change in bioelectric potential. It was found that maximum voltage generated among all the conditions was 4.24 ±2V at 15 days by using Cynodon dactylon through P-MFCs. The potential difference generated through P-MFCs was measured using a multimeter. The generation of bioelectricity was observed under different conditions like exposure to light and shade condition measured for voltage was found to be significantly different parameters. The maximum recorded under light and shade conditions were 3.82 ±2 V and 4.25 ±2 V respectively at 15 days of incubation.

Zejie Wang, Taekwon Lee, Bongsu Lim et al.

Biotechnology for Biofuels • 2014

Abstract Background The microbial fuel cell represents a novel technology to simultaneously generate electric power and treat wastewater. Both pure organic matter and real wastewater can be used as fuel to generate electric power and the substrate type can influence the microbial community structure. In the present study, rice straw, an important feedstock source in the world, was used as fuel after pretreatment with diluted acid method for a microbial fuel cell to obtain electric power. Moreover, the microbial community structures of anodic and cathodic biofilm and planktonic culturewere analyzed and compared to reveal the effect of niche on microbial community structure. Results The microbial fuel cell produced a maximum power density of 137.6 ± 15.5 mW/m 2 at a COD concentration of 400 mg/L, which was further increased to 293.33 ± 7.89 mW/m 2 through adjusting the electrolyte conductivity from 5.6 mS/cm to 17 mS/cm. Microbial community analysis showed reduction of the microbial diversities of the anodic biofilm and planktonic culture, whereas diversity of the cathodic biofilm was increased. Planktonic microbial communities were clustered closer to the anodic microbial communities compared to the cathodic biofilm. The differentiation in microbial community structure of the samples was caused by minor portion of the genus. The three samples shared the same predominant phylum of Proteobacteria. The abundance of exoelectrogenic genus was increased with Desulfobulbus as the shared most abundant genus; while the most abundant exoelectrogenic genus of Clostridium in the inoculum was reduced. Sulfate reducing bacteria accounted for large relative abundance in all the samples, whereas the relative abundance varied in different samples. Conclusion The results demonstrated that rice straw hydrolysate can be used as fuel for microbial fuel cells; microbial community structure differentiated depending on niches after microbial fuel cell operation; exoelectrogens were enriched; sulfate from rice straw hydrolysate might be responsible for the large relative abundance of sulfate reducing bacteria.

Zhiguo Gao, Ping Xue, Haibo Wang et al.

Journal of The Electrochemical Society • 2023

Formaldehyde is a common organic pollutant in water with teratogenic and carcinogenic effects. This study reports that 200 mg l −1 formaldehyde in water can be effectively degraded with generating electricity by using microbial fuel cell (MFC) technology. A novel composite anode M-Co 3 O 4 -PEDOT-GF was prepared by modifying Co 3 O 4 nanoparticles (M-Co 3 O 4 ) derived from ZIF-67 and poly (3,4-ethylenedioxythiophene) (PEDOT) on the surface of Graphite felt (GF). The results showed that the MFC loading M-Co 3 O 4 -PEDOT-GF anode exhibited excellent electricity generation performance and formaldehyde degradation. The maximum voltage of the MFC was 549 mV, 46.0% increase than that of GF anode (376 mV), and higher than N-Co 3 O 4 -PEDOT-GF anode (488 mV) modified with commercial Co 3 O 4 (N-Co 3 O 4 ). The maximum power density of the MFC loading composite anode was 4177 mW m −2 , while that of MFC loading bare GF anode was 1562 mW m −2 . The dominant microorganisms were Pseudomonadales and Rhizobiales at the order level. The removal efficiency of formaldehyde by MFC loading M-Co 3 O 4 -PEDOT-GF anode was 89.2% in 152 h. The high efficiency of formaldehyde degradation was still maintained after 10 cycles. The results could be attributed to the composite anode with loose porous three-dimensional structure and good biological compatibility of PEDOT.

Ji Ho Ahn, Ji Hun Jeong, Tong Seop Kim

Volume 3: Coal, Biomass, and Alternative Fuels; Cycle Innovations; Electric Power; Industrial and Cogeneration; Organic Rankine Cycle Power Systems • 2018

The demand for clean energy continues to increase as the human society becomes more aware of environmental challenges such as global warming. Various power systems based on high-temperature fuel cells have been proposed, especially hybrid systems combining a fuel cell with a gas turbine, and research on carbon capture and storage technology to prevent the emission of greenhouse gases is already underway. This study suggests a new method to innovatively enhance the efficiency of a molten carbonate fuel cell/micro gas turbine hybrid system including carbon capture. The key technology adopted to improve the net cycle efficiency is off-gas recirculation. The hybrid system incorporating oxy-combustion capture was devised, and its performance was compared with that of a post-combustion system based on a hybrid system. A molten carbonate fuel cell system based on a commercial unit was modeled. Externally supplied water for reforming was not needed as a result of the presence of the water vapor in the recirculated anode off-gas. The analyses confirmed that the thermal efficiencies of all the systems (MCFC stand-alone, hybrid, hybrid with oxy-combustion capture, hybrid with post-combustion capture) were significantly improved by introducing the off-gas recirculation. In particular, the largest efficiency improvement was observed for the oxy-combustion hybrid system. Its efficiency is over 57% and is even higher than that of the post-combustion hybrid system.

Jarina Joshi, Rocky Maharjan

ECS Meeting Abstracts • 2019

Microbial fuel cells (MFCs) are devices that can use microbial metabolism to degrade greenary waste from a wide range organic substrates. Alternatively, they produce electricity from microbial metabolism. Agricultural waste is a great problem in the low income country like Nepal. There are different techniques which is used for agriculture waste management. However, these techniques are time consuming and costly. Use of an efficiently designed microbial fuel cell is beneficial for proper management of organic waste of different composition. If there is production of value added products like electricity, will be the additional benefit. A significant amount of reduction in chemical oxygen demand (COD) was observed using MFC when 35% diluted solid greenery waste was used. Further, a maximum open circuit voltage of 222.7 mV was observed when MFC was operated with graphite felt electrode in anode. Vast enhancement in open circuit voltage was found when graphite felt electrode was coated with multiwalled carbon nano tubules/ polyaniline (MWCNT/PANI) was used as anode. Keyword: Microbial Fuel cell (MFC); cathode; graphite felt; Chemical Oxygen Demand (COD). References Rabaey, K., & Verstraete, W. (2005). Microbial fuel cells: Novel biotechnology for energy generation. Trends in Biotechnology , 23 (6) : 291–298. Hy Chiu, Ty Pai, MH Liu, CA Chang, FC Lo, TC Chang, HM Lo, CF Chiang, KP Chao, WY Lo, SW Lo and YL Chu (2016). Electricity Production from Municipal Solid Waste using Microbial Fuel Cells. Waste Management and Research. Pp 1-11.