Alexandros Dokouzis, Dimitra Zoi, George Leftheriotis

Materials • 2020

In the present work, we propose a new architecture for partly covered photoelectrochromic devices with a modified anode layout, so that the TiO2 film is deposited first on the substrate, covering a small part of its surface, followed by the WO3 film that covers the remaining device area. As a result, the TiO2 film can be subjected to the proper thermal and chemical treatment without affecting the electrochromic performance of the WO3 film. The proposed design led to photoelectrochromic (PEC) devices with a power conversion efficiency (PCE) four times higher than that of typical partly covered devices, with a measured maximum of 4.9%. This, in turn, enabled a reduction in the total area covered by the photovoltaic unit of the devices by four times (to 5% from 20%), thus reducing its visual obstruction, without affecting the depth, uniformity and speed of coloration. A detailed study of the parameters affecting the performance of the new devices revealed that, with the cover ratio decreasing, PCE was increasing. The photocoloration efficiency also exhibited the same trend for cover ratio values below 15%. Storage of the devices in short circuit conditions was found to accelerate optical reversibility without affecting their photovoltaic and optical performance.

Mengkun Tian, Wesley Tennyson, Alexander Blair Papandrew et al.

ECS Meeting Abstracts • 2017

Solid acid fuel cells (SAFC) working at intermediate temperature (250°C) have many advantages compared to the lower temperature proton exchange membrane fuel cell (PEMFC), such as increased catalyst activity and are more resistant to CO poisoning. 1, 2 The state-of-the-art cathode is comprised of porous protonic conductor coated by Pt. 3, 4 There are two major roles of Pt in the cathode: (1) the oxygen reduction reaction (ORR) catalyst and (2) the electron conductor. To maintain a highly electron conductive network, a high fraction of Pt has to be loaded in ‘conventional’ SAFC electrodes. However, to generate wider application, the cost of the cathode must be reduced significantly. The function of Pt as electron conductor can be replaced by the catalyst support to achieve this reduction in loading. The catalyst support must have high electron conductivity, corrosion-resistance and high surface area. The carbon nanostructures are the common catalyst supports used in the fuel cells. In our previous studies, we demonstrated that multi-wall carbon nanotubes are much more stable during fuel cell testing compared to the single wall carbon structures. 5 Indeed, pure single layer or few-layer carbon supports are well known to be particularly vulnerable to corrosion in the present of water. However, previous research showed that substitutional boron can lower the electron density of the reactive carbon, leading to a reduction in the rate of O 2 chemisorption. 6 Meanwhile, very small amounts of boron (~1%) have been demonstrated to enhance the conductivity of the single carbon structure. 7 In our recent studies, we synthesize the pure single wall carbon, carbon structures in hydrogen gas and with boron loading. Surprisingly, the boron loading induces the growth of few-layer graphenes (FLGs), which exhibit much better corrosion resistance than the single wall carbon and carbon synthesized in hydrogen gas which consists of multi-wall and single-wall carbon structure. In this research, we focus on the structural investigation of those FLGs. Characterization of the FLGs are performed by high resolution transmission electron microscopy (HRTEM) imaging, monochromated electron energy-loss spectroscopy (EELS), nano-beam electron diffraction (NBED), aberration corrected scanning transmission electron microscopy (STEM) imaging, X-ray photoelectron spectroscopy (XPS), nuclear magnetic resonance (NMR), Raman spectroscopy and X-ray diffraction (XRD). Representative STEM images in a low and high magnification are shown in Figure 1 (a)-(b). A significantly structure deviation compared to pure graphene/graphite is evident due to 1-3% boron loading. Those results indicate the few-layer graphene does not stack in a normal graphitic way in the c direction. The EELS, XPS and NMR show complicated electronic states of the boron in the carbon, implying boron does not have to be in the substitutional site. For example, Figure 1(c) show a representative EELS spectrum taken from a FLG. The featureless boron K-edge looks like to be taken from amorphous boron instead of substitutional boron. This result is also supported by the NBED and XRD, showing a non-flat features of the FLGs. Finally, we used the density functional theory (DFT) to explain the excellent oxygen resistance of FLG with this unique structure. Acknowledgments This work is supported by ARPA-E via cooperative agreement DE-AR0000499. The synthesis science is supported by BES-MSED. We thank JIAM and CNMS for microscopy use. Reference 1. K. Ishiyama, F. Kosaka, I. Shimada, Y. Oshima and J. Otomo, Journal of Power Sources, 2013, 225, 141-149. 2. A. B. Papandrew, R. W. Atkinson Iii, R. R. Unocic and T. A. Zawodzinski, Journal of Materials Chemistry A, 2015, 3, 3984-3987. 3. A. B. Papandrew, C. R. I. Chisholm, R. A. Elgammal, M. M. Özer and S. K. Zecevic, Chemistry of Materials, 2011, 23, 1659-1667. 4. A. B. Papandrew, C. R. I. Chisholm, S. K. Zecevic, G. M. Veith and T. A. Zawodzinski, Journal of The Electrochemical Society, 2013, 160, F175-F182. 5. A. B. Papandrew, R. A. Elgammal, M. Tian, W. D. Tennyson, C. M. Rouleau, A. A. Puretzky, G. M. Veith, D. B. Geohegan and T. A. Zawodzinski, Journal of Power Sources, 2017, 337, 145-151. 6. B. Yuan, W. Xing, Y. Hu, X. Mu, J. Wang, Q. Tai, G. Li, L. Liu, K. M. Liew and Y. Hu, Carbon, 2016, 101, 152-158. 7. M. Harada, T. Inagaki, S. Bandow and S. Iijima, Carbon, 2008, 46, 766-772. Figure 1

Hwijin Seo, Anna Joicy, Myoung Eun Lee et al.

Energies • 2023

Ultrasound and combined alkaline–ultrasound pretreatment (AUP) strategies were examined for primary sewage sludge (SS) disintegration and were utilized to evaluate the degree of solubilization (DS). Further, the pretreated primary SS was operated in microbial electrolysis cells (MECs) to maximize methane production and thereby improve the reactor performance. The highest DS of 67.2% of primary SS was recorded with the AUP. MEC reactors operated with the AUP showed the highest methane production (240 ± 6.4 mL g VSin−1). VS (61.1%) and COD (72.2%) removal in the MEC ALK-US showed the best organic matter removal efficiency. In the modified Gompertz analysis, the substrate with the highest degree of solubilization (AUP) had the shortest lag phase (0.2 ± 0.1 d). This implies that forced hydrolysis via pretreatment could enhance biodegradability, thereby making it easy for microorganisms to consume and leading to improved MEC performances. Microbial analysis implicitly demonstrated that pretreatment expedited the growth of hydrolytic bacteria (Bacteroidetes and Firmicutes), and a syntrophic interaction with electroactive microorganisms (Smithella) and hydrogenotrophic methanogens (Methanoculleus) was enriched in the MECs with AUP sludge. This suggests that the AUP strategy could be useful to enhance anaerobic digestion performance and provide a new perspective on treating primary SS in an economical way.

Alexander Schenk, Stefan Gamper, Christoph Grimmer et al.

ECS Meeting Abstracts • 2016

High-temperature polymer electrolyte fuel cells (HT-PEFCs) are a suitable technology for decentralized small scale electricity and heat production. HT-PEFCs do not require hydrogen infrastructure and are characterized by a simpler and therefore less expensive system compared to available fuel cell systems. In combination with a reformer unit, HT-PEFC systems offer an efficiency gain over conventional combustion of hydrocarbons, such as natural gas. In near future, HT-PEFCs will be even more effective and efficient when renewable biofuels and hydrogen are widespread available. We present an efficient HT-PEFC based combined heat and power (µ-CHP) system for the provision of electrical energy and hot water in single family households (see Table 1). Due to the optimized design and layout of the fuel cell based µ-CHP system and the respective manufacturing processes of the catalysts and the membrane electrode assemblies (MEA), the demand for cost effective and greenhouse gas efficient energy at customer level is addressed. Major efforts were devoted to the establishment of scalable catalyst deposition methods, which enable a loss-free utilization of precious metals. By using appropriate multimetallic catalyst systems at anode and cathode, the precious metal loading was reduced by approx. 20% in comparison to commercially available electrodes without compromising performance (see Figure 1) [1]. Furthermore, by introducing post-preparation treatments, the stability of the catalysts was enhanced over commercial Pt/C. The activity and stability of the catalyst systems were evaluated ex situ by means of cyclic voltammetry and accelerated stress tests using a rotating disk electrode (RDE) setup. Furthermore, the catalyst systems were characterized in situ by means of polarization curves, continuous operation, accelerated stress tests and electrochemical impedance spectroscopy measurements at single cell, stack and at system level (see Figure 1). Acknowledgment Financial support was provided by The Climate and Energy Fund of the Austrian Federal Government and The Austrian Research Promotion Agency (FFG) through the program Energieforschung (e!Mission). [1] A. Schenk, C. Grimmer, M. Perchthaler, S. Weinberger, B. Pichler, C. Heinzl, C. Scheu, F.-A. Mautner, B. Bitschnau, V. Hacker, Platinum–cobalt catalysts for the oxygen reduction reaction in high temperature proton exchange membrane fuel cells – Long term behavior under ex-situ and in-situ conditions, J. Power Sources. 266 (2014) 313–322. Figure 1

Nancy Hammad, Amr El-Nemr, Ibrahim G. Shaaban

Applied Sciences • 2024

Alkali-activated slag (AAS) materials are one of the most promising sustainable construction composites. These novel materials are highly characterized by their improved mechanical and durability properties. Nevertheless, the high shrinkage rate hinders their full-scale applications. The low Ca/Si ratio, complex hydration process, and fine pore microstructure are the main causes of the reported shrinkage behavior. This study introduces Bacillus subtilis culture for healing the cracking behavior. The enzymatic action leads to precipitating calcium carbonate crystals that fill AAS cracks and pores. Incorporating calcium oxide has been recommended in multiple studies. The main purpose of adding calcium oxide is to enhance the engineering properties of AAS and provide more calcium ions for the biochemical reactions induced by the added bacteria. However, inconsistent findings about the influence of calcium oxide have been reported. This research provides further insights into the effect of calcium oxide (CaO) on the performance of microbial self-healing efficiency in AAS composite. The results highlight that incorporating calcium oxide as 7% of the binder partial replacement has an impact on the engineering properties of bio-AAS materials. The study recommends correlating the percentage of free calcium ions within the AAS mixture with the microbial activity.

Abul K. Azad, Abdalla M. Abdalla, Ahmed Afif et al.

Research Square • 2021

Abstract Protonic ceramic fuel cells (PCFCs) have become the most efficient, clean and cost-effective electrochemical energy conversion devices in recent years. While significant progress has been made in developing proton conducting electrolyte materials, mechanical strength and durability still need to be improved for efficient applications. We report that adding 5 mol% Zn to the Y-doped barium cerate-zirconate perovskite electrolyte material can significantly improve the sintering properties, mechanical strength, durability and performance. Using same proton conducting material in anodes, electrolytes and cathodes to make a strong structural backbone shows clear advantages in mechanical strength over other arrangements with different materials. Rietveld analysis of the X-ray and neutron diffraction data of BaCe 0.7 Zr 0.1 Y 0.15 Zn 0.05 O 3-δ (BCZYZn05) revealed a pure orthorhombic structure belonging to the Pbnm space group. Structural and electrochemical analyses indicate highly dense and high proton conductivity at intermediate temperature (400-700 °C). The anode-supported single cell, NiO-BCZYZn05 | BCZYZn05 | BSCF-BCZYZn05, demonstrates a peak power density of 872 mW cm -2 at 700 °C which is one of the highest power density in an all-protonic solid oxide fuel cell. This observation represents an important step towards commercially viable SOFC technology.

Yi-Tang Chang, Chu-Wen Yang, Yu-Jie Chang et al.

BioMed Research International • 2013

Synthetic sewage containing high concentrations of pharmaceuticals and personal care products (PPCPs, mg/L level) was treated using an anoxic/aerobic (A/O) reactor coupled with a microbial fuel cell (MFC) at hydraulic retention time (HRT) of 8 h. A novel design of solid plain graphite plates (SPGRPs) was used for the high surface area biodegradation of the PPCP-containing sewage and for the generation of electricity. The average COD Cr and total nitrogen removal efficiencies achieved were 97.20% and 83.75%, respectively. High removal efficiencies of pharmaceuticals, including acetaminophen, ibuprofen, and sulfamethoxazole, were also obtained and ranged from 98.21% to 99.89%. A maximum power density of 532.61 mW/cm 2 and a maximum coulombic efficiency of 25.20% were measured for the SPGRP MFC at the anode. Distinct differences in the bacterial community were presented at various locations including the mixed liquor suspended solids and biofilms. The bacterial groups involved in PPCP biodegradation were identified as Dechloromonas spp., Sphingomonas sp., and Pseudomonas aeruginosa . This design, which couples an A/O reactor with a novel design of SPGRP MFC, allows the simultaneous removal of PPCPs and successful electricity production.

Jeffrey Book, Joel Golden, Ian Martens et al.

ECS Meeting Abstracts • 2018

Described here are the latest results from field tests of the Benthic Microbial Fuel Cell (BMFC). The BMFC sits on the sediment/water (benthic) interface of marine environments where it utilizes organic matter naturally residing in marine sediments as its fuel and oxygen in overlying water as its oxidant to generate electrical power. Both fuel and oxidant are used as found in the environment. The BMFC is expected to generate power indefinitely due to constant replenishment of organic matter and oxygen by naturally occurring mass transport (i.e., diffusion, advection, and tidal pumping); durability of its electrode catalysts consisting of self-forming biofilms comprised of microorganisms naturally inhabiting the benthic interface; and lack of moving, degrading, or depleting components. The BMFC is being developed to persistently power battery-powered oceanographic sensors presently limited in operational lifetime by battery depletion. During the past 10 years, we have successfully deployed small scale (< 0.1 Watt continuous output) BMFCs in coastal waters world wide ranging in depth from < 1 m to > 1000 m over for up to 2 years before being retrieved without any depletion in power output; and have powered a riverine metrological buoy with a radio transceiver link, a hydrophone with a radio transceiver link, and a surveillance camera with a cellular link. The highest power density we have thus far achieved is 0.39 Watt continuous power per square meter footprint area of sediment surface occupied by an early prototype that required extensive in-water manipulation by divers to deploy. This BMFC had a 29-liter volume, a 0.09-square meter footprint area (area of sediment surface occupied), and sustained 0.036 Watt continuously. Subsequently, by scaling up this BMFC we achieved the highest sustained power by a BMFC of 0.47 Watt continuous power (370 liter, 1.2 square meter footprint area, 0.39 Watt continuous power per square meter footprint area). Based on the 3.1 square meter footprint area of the oceanographic moorings we presently use to house battery-powered sensors, our long-term goal of a BMFC-equipped mooring capable of sustaining > 1 Watt is thought achievable. This amount of power, the equivalent of 440 alkaline D cells per year of operation based on optimal battery performance, is more than sufficient to operate complicated oceanographic instruments (e.g., an acoustic Doppler current profiler), including processing and transmitting data at least once a day either by acoustic telemetry or by radio to satellites. Practical considerations that limit the size of oceanographic battery packs (weight, cost, and size) compounded by poor battery performance at low temperatures encountered at the bottom of most marine environments limit the duration of most battery-powered sensors to 1 year. In contrast, the putative unlimited duration of BMFCs make them appealing for long-duration applications if BMFCs can be reliably deployed without in-water manipulation. Our current efforts to be reported on here center on iterative design and evaluation of full scale (targeting > 1 Watt continuous power) by BMFCS that do not require in-water manipulation by divers and/or remotely operated vehicles to deploy (i.e., drop and go). The challenge for deployment is the requirement that the anode be in contact with anoxic sediment and isolated from over lying oxic water. Our most recent design, to be described here, sustained 0.03 W continuous power when configured with a 1-m diameter bottom mount sensor mooring and was deployed without in-water manipulation. The power is intended to increase dramatically for each design-evaluation cycle and is projected to reach > 1 Watt continuous power as the mass-transport accessible surface area of the anode is increased. At this time 2 BMFC-equipped moorings are undergoing field testing. In addition to describing the results of these field tests, results of earlier deployments will be presented in which the dependency of BMFC power output vs sediment properties and environmental conditions was evaluated.

Gábor Márk Tardy, Bálint Lóránt, Miklós Gyalai-Korpos et al.

Biotechnology Letters • 2020

Abstract Objectives Single-chamber air cathode microbial fuel cells (MFCs) were applied as biosensors for biochemical oxygen demand (BOD) measurement of real wastewaters with considerable suspended and/or slowly biodegradable organic content. Results The measurement method consists of batch sample injection, continuous measurement of cell voltage and calculation of total charge (Q) gained during the biodegradation of organic content. Diverse samples were analyzed: acetate and peptone samples containing only soluble readily biodegradable substrates; corn starch and milk samples with suspended and colloidal organics; real domestic and brewery wastewaters. Linear regression fitted to the Q vs. BOD 5 measurement points of the real wastewaters provided high (> 0.985) R 2 values. Time requirement of the measurement varied from 1 to 4 days, depending on the composition of the sample. Conclusions Relative error of BOD measured in the MFCs comparing with BOD 5 was less than 10%, thus the method might be a good basis for the development of on-site automatic BOD sensors for real wastewater samples.

Jinrong Lu, Linde Ren, Cheng Li et al.

New Journal of Chemistry • 2022

Herein, the output power density produced by Zn/Co-S-3DHFLM as the cathode catalyst of an MFC was higher than that of Co-3DHFLM.

F. Khaled, B. Allard, O. Ondel et al.

Energy Harvesting and Systems • 2015

Cover letter An autonomous flyback converter was designed for energy harvesting from Microbial Fuel Cells (MFCs). The circuit was optimized to minimize the losses and maximize the efficiency. A Maximum Power Point Tracking (MPPT) algorithm was implanted in the converter to extract the maximum power available from MFC. Discontinuous conduction mode operation of the flyback allows controlling the MPP operation by impedance matching. The flyback can start-up at low voltage, around 300 mV. The output open circuit voltage is about 20 V and the voltage at MPP is 6.4 V with a maximum efficiency of 71.2%. Abstract : Microbial fuel cells (MFCs) use bacteria as the catalysts to oxidize organic matter and generate electricity. This energy can be used to supply low power electronic systems. A power management unit between the MFCs and the load is required to adapt the voltage and control the operation. The low voltage and low power characteristics of MFCs prohibit the use of standard converter topologies since the threshold voltage of standard CMOS transistors in CMOS technology is higher than the output voltage of MFCs. A low-voltage start-up sub-circuit is required to charge a primary capacitor to supply the driver. A specific sub-circuit is also required to control the operation of MFCs for Maximum Power Point Tracking (MPPT) issues. An optimized Discontinuous Conduction Mode (DCM) autonomous flyback converter for energy harvesting is presented for ambient sources, like MFCs. The converter is designed, fabricated, and tested. An MPPT algorithm is integrated in the system to control the operation and to extract the maximum available power from the MFC. The converter is able of start and step-up MFC output voltage to a value higher than 3 V under load. The peak efficiency of the converter is 71.2%.

Tuoyu Zhou, Rong Li, Shuting Zhang et al.

Biotechnology and Bioengineering • 2020

Abstract Copper pollution poses a serious threat to the aquatic environment; however, in situ analytical methods for copper monitoring are still scarce. In the current study, Escherichia coli Rosetta was genetically modified to express OprF and ribB with promoter P t7 and P cusC , respectively, which could synthesize porin and senses Cu 2+ to produce riboflavin. The cell membrane permeability of this engineered strain was increased and its riboflavin production (1.45–3.56 μM) was positively correlated to Cu 2+ (0–0.5 mM). The biosynthetic strain was then employed in microbial fuel cell (MFC) based biosensor. Under optimal operating parameters of pH 7.1 and 37°C, the maximum voltage (248, 295, 333, 352, and 407 mV) of the constructed MFC biosensor showed a linear correlation with Cu 2+ concentration (0.1, 0.2, 0.3, 0.4, 0.5 mM, respectively; R 2 = 0.977). The continuous mode testing demonstrated that the MFC biosensor specifically senses Cu 2+ with calculated detection limit of 28 μM, which conforms to the common Cu 2+ safety standard (32 μM). The results obtained with the developed biosensor system were consistent with the existing analytical methods such as colorimetry, flame atomic absorption spectrometry, and inductively coupled plasma optical emission spectrometry. In conclusion, this MFC‐based biosensor overcomes the signal conversion and transmission problems of conventional approaches, providing a fast and economic analytical alternative for in situ monitoring of Cu 2+ in water.

Jayanta Gogoi, Karan N, Abhishek Nalwad et al.

Water Practice & Technology • 2024

ABSTRACT This study developed a nature-based pilot-scale technology for simultaneous piggery WW treatment and resource recovery potential. The technology comprised a two-stage vertical flow constructed wetland (2-VFCW) integrated with a microbial fuel cell (MFC) and microalgal photobioreactor. The first and second stage was an unsaturated and saturated type, respectively. The bioelectricity generation was optimised by investigating the suitable electrode zonation, hydraulic retention time (HRT) and WW loading rate. The 2-VFCW-MFC-treated effluent was studied to grow microalgae for biomass production. The 2-VFCW-MFC showed better treatment efficiency than the 2-VFCW, possibly due to enhanced microbial activity on the electrode surface, leading to improved organic matter degradation and electron transfer to the cathode, enhancing NO3− and PO43− reduction. The 2-VFCW-MFC with electrode zonation of 20 cm (cathode) and 60 cm (anode) and HRT of 76 h, 48 min showed the highest open-circuit voltage of 291.83+13.53 mV and WW treatment efficiency. The highest algal biomass of 21,323.34+8,316.26 mg/L (wet weight) was produced at HRT of 96 h, then entered the death phase. Comparatively, the 2-VFCW-MFC showed higher WW treatment efficiency than 2-VFCW at 2 L/day by 23.24% COD, 27.43% TOC, 33.05% PO43−, 13.51% NO3−, 8.14% TN, except TAN (22.71%).

Rickelmi Agüero-Quiñones, Magaly De La Cruz-Noriega, Walter Rojas-Villacorta

Bioengineering • 2025

The projected global energy demand for 2050 drives the imperative search for alternative and environmentally friendly energy sources. An emerging and promising alternative is microbial fuel cells assisted with microalgae. This research evaluated the potential of Chlorella sp. biomass in electricity production using microbial fuel cells (MFCs) with a single chamber and activated carbon and zinc electrodes at the laboratory scale over 20 days of operation. Maximum values of voltage (1271 ± 2.52 mV), current (4.77 ± 0.02 mA), power density (247.514 mW/cm2), current density (0.551 mA/cm2), and internal resistance (200.83 ± 0.327 Ω) were obtained. The biomass-maintained pH values of 7.32 ± 0.03–7.74 ± 0.02 and peaks of electrical conductivity of 2450 ± 17.1 µS/cm and oxidation-reduction potential of 952 ± 20 mV were reached. Meanwhile, cell density and absorbance increased to average values of 2.2933 × 107 ± 1.15 × 106 cells/mL and 3.471 ± 0.195 absorbance units (AU), respectively. Scanning electron microscopy micrographs allowed the observation of filamentous structures of the formed biofilm attached to carbon particles, and energy-dispersive X-ray spectroscopy spectra of the anodes determined the predominance of oxygen, carbon, silicon, aluminum, and iron. Finally, this research demonstrates the great potential of Chlorella sp. biomass for sustainable bioelectricity generation in MFCs.

Salvatore Angelo Cancemi, Michela Angelucci, Rosa Lo Frano et al.

Volume 11: Student Paper Competition • 2024

Abstract In nuclear reactor fuel engineering, the phenomena of Pellet-Cladding Interaction (PCI) and Pellet-Cladding Mechanical Interaction (PCMI) present significant challenges. These issues affect the design and safety of NPPs, mainly due to factors like fission gas release and fuel swelling. Accurately modeling these interactions is complex, as they are complexly linked with the fuel’s neutronic and thermal responses. Traditionally, the simulation of these interactions, essential for nuclear safety and risk assessment, has been complex and resource intensive. This study focuses on developing innovative surrogate models to enhance computational efficiency in nuclear fuel code analysis. A surrogate model based on a neural network approach is a data-driven computational model that approximates the behavior or output of complex, time-consuming, or resource-intensive simulations. This study specifically employs Artificial Neural Networks (ANNs) and statistical algorithms, aiming to reduce high computational cost of traditional approaches. A validated synthetic dataset, representing thermal analysis under steady-state conditions, is used to train the machine learning model. The dataset specifically focuses on Cladding Temperature. The study investigates eight different Test-Case. The surrogate model, trained on only 20% of the dataset, can predicts the entire time series of temperature using ARIMA, LSTM, and Prophet algorithms. The maximum error achieved by the surrogate model is 3.19°C compared to the validated temperature. The study demonstrates that surrogate models offer a time-efficient alternative for simulating complex physical phenomena, achieving a balance between accuracy and efficiency. This approach is particularly beneficial in scenarios where full-scale 2D and 3D simulations are excessively time-consuming, providing quicker results and significantly reducing computational resources.

Anil N. Ghadge, Dipak A. Jadhav, Makarand M. Ghangrekar

Environmental Progress & Sustainable Energy • 2016

Performance of 45 L pilot scale microbial fuel cell (MFC) made from glass fiber‐reinforced plastic and ceramic‐separators (CS) with multiple electrode assembly was evaluated. Study on effect of external resistance ( R ext ) varying from 100 to 3 Ω revealed that maximum power ( P max ) of 14.28 mW (37.8 mA current) with chemical oxygen demand (COD) removal of 84 ± 5.1% was observed at R ext of 10 Ω. While evaluating influence of organic loading rate (OLR) from 0.75 to 8 g COD L −1 d −1 , the MFC showed P max of 17.63 mW (42 mA current) and COD removal of 69 ± 5.1% at OLR of 4.5 g COD L −1 d −1 . Internal resistance ( R int ) of 12.4 Ω observed is among the least value reported in literature for larger MFCs. Simplicity in design, ease of fabrication, lower R int , longevity and low cost CS, which can withstand more hydraulic pressure than polymeric membranes, are the advantages that this MFC offers to make it suitable for field applications. © 2016 American Institute of Chemical Engineers Environ Prog, 35: 1809–1817, 2016

Aline Oliveira da Silva, Simone Perazzoli, Hugo Moreira Soares et al.

Engenharia Sanitaria e Ambiental • 2023

ABSTRACT The aim of this study was to assess the feasibility of using cassava wastewater as a substrate for dual-chamber microbial fuel cells (MFCs) operating with denitrifying biocathodes. Two configurations related to the ion exchange membrane used were evaluated: one with an anion exchange membrane (MFC-A) and the other with a cation exchange membrane (MFC-C). Both bioreactors were operated in sequential batch mode. Furthermore, a low-cost platform based on Arduino technology was also proposed to enable continuous measurement and recording of voltage data from the MFCs. The highest voltage values were observed in the first days of MFC operation, with readings reaching approximately 350 mV (0.41 W·m 3) and gradually decreasing after 100 days of operation to 243 mV (0.20 W·m 3) and 125 mV (0.05 W·m 3) for the MFC-A and MFC-C, respectively (mean values for the last 20 days of operation). In both MFCs, the chemical oxygen demand reduction and nitrogen removal were over 98% after reactor stabilization, with no noticeable nitrite accumulation. The experimental results indicated superior performance when MFC was equipped with an anion exchange membrane. The results presented here demonstrate the feasibility of using cassava wastewater as a viable substrate for MFCs equipped with a denitrifying biocathode, allowing for efficient wastewater treatment and simultaneous electricity generation.

, Erich J. Mace, Yossef A. Elabd

• 2011

Proton-exchange membrane fuel cells (PEMFCs) are promising as high-efficiency energy conversion devices, but the need for expensive noble metal catalysts such as Pt has hindered commercialization. An alternative is the alkaline membrane fuel cell (AMFC), which intrinsically possesses faster kinetics at the cathode, enabling noble metals to be replaced by Co, Ag, Fe, or Ni. In order to compete with PEMFCs (i.e. achieve 1.0 W/cm2 power density), AMFCs require improved membranes. In particular, membranes must achieve conductivities of ~0.1 S/cm and be thermally, chemically, and mechanically stable. The membrane mass transport phenomena governing conduction should be clearly understood in order to efficiently develop new materials. In particular, there is need for an improved, molecularlevel understanding of the relationship between membrane water content and membrane conductivity, as well as an elucidation of the kinetic mechanism causing membrane carbonation. The dependency of conductivity on membrane water content is explored using Fourier Transform Infrared Attenuated Total Reflectance (FTIR-ATR) spectroscopy with twodimensional correlation techniques, and Electrochemical Impedance Spectroscopy (EIS). The particular role that specific water cluster states play during transport is elucidated, and the transient behavior associated with membrane carbonation is explored.

M. Priya, N. Ramesh Raju, V Madhavi et al.

International Journal of Advanced Research in Science, Communication and Technology • 2025

The Modular-Multilevel Converter (M-MC) has substantially contributed to the integration of non-conventional energy sources into grid systems, particularly Proton Exchange Membrane Fuel Cells (PEMFC). This paper proposes an M-MC system to interface PEMFC with the grid, focusing on controlling circulating currents and ensuring stability. A Fuzzy Logic is employed to mitigate circulating current (CC) harmonics. Phase-Shifted Carrier (PSC) modulation is used to improve capacitor voltage balancing, thus maintaining a constant input voltage. The boost converter enhances the input voltage to a higher level, which is essential for maintaining the necessary voltage margin in MMC. The main contribution of this paper is (I)The PSC-PWM was implemented for MMC to maintain a quality +y of output voltage by the control of capacitor voltages.(II)The proposed fuzzy logic controlled circulating current must be achieved in order to regulate the dc ripple component, arm current, and circulating current of MMC.(III)It is essential to regulate the SM capacitor voltages in order to provide a balanced and equal output while maintaining the ratings and limits of the SMs, and this will be accomplished.

Ivonne L. Alonso-Lemus, Carlos Cobos-Reyes, Mayra Figueroa-Torres et al.

Journal of Chemistry • 2022

In this work, electroactive biofilms of Bacillus subtilis (B. subtilis) or Escherichia coli (E. coli) were supported on functionalized biocarbon (AB7-F), which was synthesized from waste leather and was used as catalysts to develop bioanodes for microbial fuel cells (MFCs). This way, bioanodes were fabricated and further evaluated in a three-electrode cell using pharmaceutical wastewater (PWW) as substrate. The electrochemical measurements showed a higher performance of the bioanode based on AB7-f+ B. subtilis to oxidize organic matter from PWW. The polarization curves in the dual-chamber MFC showed that AB7-f+ B. subtilis bioanode can generate an open circuit voltage of 602 mV and a power density of 77 mW m−2. During long-term tests of the MFC, a variation in performance was observed, with a maximum of 96.3 mW m−2 on day 7. Such variation was attributed to the development of more stable biofilm as well as consumption of some compounds metabolized by bacteria grown on the bioanode. The results showed that AB7-f+ B. subtilis can be used as bioanode for MFCs with PWW as substrate removing around 45% of the chemical oxygen demand (COD).

Zijie Wu, Zhengyang Ni, Mengmeng Qin et al.

SmartMat • 2024

Abstract Microbial fuel cells (MFCs) benefit from the introduction of iron in the anode, as its multiple valence states and high electron‐catalytic activity led to improved power densities in MFCs. However, the effect of long‐term Fe 3+ release into the electrolyte on the power density of MFCs is often overlooked. Herein, an anode consisting of a three‐dimensional iron foam uniformly coated by reduced graphene oxide (rGO/IF) with a suitable loading density (8 g/m 2 ) and a large specific surface area (0.05 m 2 /g) for high‐density bacterial loading was prepared. The hybrid cells based on the rGO/IF anode exhibit a maximum power density of 5330 ± 76 mW/m 2 contributed by MFCs and galvanic cells. The rGO/IF anode enables continuous Fe 3+ release for high electron‐catalytic activity in the electrolyte during the discharging of the galvanic cells. As a result, the hybrid cells showed a power density of 2107 ± 64 mW/m 2 after four cycles, facilitated through reversible conversion between Fe 3+ and Fe 2+ in the electrolyte to accelerate electron transfer efficiency. The results indicate that the rGO/IF anode can be used for designing and fabricating high‐power MFCs by optimizing the rate of release of Fe 3+ in the electrolyte.

Ayesha Kausar, Ishaq Ahmad, Tingkai Zhao et al.

Journal of Composites Science • 2023

Fuel cell efficiency can be improved by using progressive electrodes and electrolytes. Green nanomaterials and green technologies have been explored for the manufacturing of high-performance electrode and electrolyte materials for fuel cells. Platinum-based electrodes have been replaced with green materials and nanocomposites using green fabrication approaches to attain environmentally friendly fuel cells. In this regard, ecological and sustainable electrode- and electrolyte-based membrane electrode assemblies have also been designed. Moreover, green nanocomposites have been applied to form the fuel cell electrolyte membranes. Among fuel cells, microbial fuel cells have gained research attention for the incorporation of green and sustainable materials. Hence, this review essentially focuses on the potential of green nanocomposites as fuel cell electrode and electrolyte materials and application of green synthesis techniques to attain these materials. The design of and interactions with nanocomposites have led to synergistic effects on the morphology, impedance, resistance, power density, current density, electrochemical features, proton conductivity, and overall efficiency. Moreover, we deliberate the future significance and challenges of the application of green nanocomposites in electrodes and electrolytes to attain efficient fuel cells.

Pavlina Theodosiou, Ioannis Ieropoulos, John Greenman et al.

ECS Meeting Abstracts • 2017

Introduction: Renewable energy production from waste using microbial fuel cell (MFC) technology is attracting increasing attention. MFCs are bio-electrical devices that use microorganisms as biocatalysts to convert chemical energy (stored in organic matter) into electrical energy. MFCs consist of a positive cathode and a negative anode, which are separated by a semi-permeable membrane. Microorganisms are inoculated in the anodic compartment and through substrate oxidation, release electrons to the anode electrode. The two electrodes are connected by an external circuit, which facilitates the flow of electrons from the anode to the cathode. One of the main contributors affecting the cost and performance of MFCs is the membrane, since these tend to be quite expensive, even though they are commercially available. To overcome this, alternative materials and configurations need to be identified. One design is the membrane electrode assembly (MEA) that improves power output by reducing the internal resistance. This study looks at 3D printing MFCs using novel extrude-able materials that can emerge from the Evobot platform (Figure 1). The focus is on the development of cost-effective MEA using extrude-able air-dry membranes painted with conductive paint. Materials and Methods: Twelve cubic analytical size MFCs were assembled with only one chamber forming the 25mL anode, so as to have an oxygen-diffusion cathode, whilst the membranes were glued to the anode chamber. For this experiment, three types of potentially extrude-able membranes were tested against a conventional CEM. These materials were two air-dry clays; Fimo and terracotta and standard terracotta clay (Figure 2A). The latter was kilned at a temperature of 1070 o C prior to use, to allow the structural bonding of the clay and ensure durability, whereas the rest were dried overnight at room temperature. The thickness of the tested membranes was consistent for all the custom made membranes (2.5mm). The control membrane required activation in 5% NaCl prior to use. A conductive graphite coating was applied to each membrane and formed the cathode electrode (Figure 2B). The coating was fabricated using polyurethane rubber coating (PlastiDip), white spirit and graphite powder. The membranes were coated with the conductive cathode mixture and the surface resistance was measured for each coating, until the lowest value was achieved (100-200 Ohms). After the membrane electrode assembly had dried, a cable was attached to the cathode using conductive wire glue, to form the cathodic current collector. The MFCs were then partially wrapped with Parafilm® to ensure moisture retention in the open-to-air cathode side (Figure 2C). All the cells were inoculated with activated sludge and fed with neat human urine collected anonymously from healthy individuals. Results and Discussion: Initially, the air-dry terracotta outperformed the other materials (70 µW), whereas the commercially available and most commonly used CEM was the least performing (30 µW). Air-dry Fimo and kilned terracotta were almost identical in terms of power output (50 µW). The experiment started with a 2.7 kΩ load, and although initially the air-dry clay was outperforming the rest, after fourteen days, both air-dry clay and fimo were identical. Following electrochemical analysis, the optimal external resistance was identified (1 kΩ). Once the MFCs were run at this resistance value the performance levels had clearly diverged and Fimo outperformed the other materials. The results from the polarisation experiment showed a difference with the real-time data, suggesting that the air-dry clay was the best performing with 123 μW, followed by Fimo with an output of 79 μW. However, in all cases, the soft materials were operating better than the conventional cation exchange membrane. The materials tested as alternative membranes come in the form of soft modelling clay, which makes these suitable for extrusion from the EVOBOT platform. As the original form of the electrode material is fluid, it can also be applied using EVOBOT by incorporating a brush/roller on the actuation layer of the robot. This will apply the conductive coating onto the dried extruded membranes, and help produce a uniform layer on the surface. Conclusions: The findings presented in this study demonstrate for the first time that soft materials cured in air can be used as membranes for MFCs, and in addition, even improve power output. This offers a great advantage over the conventional and expensive CEMs, and is a novelty in the MFC field. The EVOBOT robotic platform is flexible and can be modified to extrude such membranes. This is an exciting development and a step towards the overall goal of the EVOBLISS project, which is to monolithically 3D-print MFCs using EVOBOT. Figure 1

I. Ieropoulos, J. Greenman, D. Lewis et al.

Journal of Water, Sanitation and Hygiene for Development • 2013

This study builds on the previous work of urine utilisation and uses small-scale microbial fuel cells (MFCs), working both as individual units in cascade or collectively as a stack, to utilise artificial urine. Artificial urine was prepared at concentrations typically found in real human urine with peptone employed as a surrogate proteinacious component. MFCs were constructed from Nanocure® polymer using rapid prototype technology. The anode and cathode electrodes were made of 15 cm2 carbon veil, folded down to fit in the 1 mL chambers. Eight MFCs were inoculated using activated anaerobic sludge; after 17 days of fed batch mode they were switched to continuous flow, initially at 0.09 mL/h and subsequently at 0.43 mL/h, resulting in HRT of 12.69 minutes/MFC. MFCs showed stable performance following the maturing period and produced, under polarisation experiments, peak power levels of 117 μW, corresponding to 962.94 W/m3. Continuous flow experiments data showed higher power production, increasing with the concentration of the carbon/energy source within artificial urine. The work demonstrates that artificial urine of varying composition can be successfully utilised for the production of energy and concomitant cleanup of organic waste. Finally, in line with the practical implementation and robotics work in our group, the small-scale MFCs were configured into a stack and directly energised electronic devices.

Kumar Sonu, Monika Sogani, Zainab Syed et al.

Environmental Progress & Sustainable Energy • 2021

Abstract The key operational constraints of the microbial fuel cell (MFC) technology in achieving its due potential are the high cost of electrodes and the difficulties in scaling up. To address these issues, carbonized corncob anodes were prepared and modified with the hydrogen peroxide (H 2 O 2 ) to increase the oxygenated functional groups favoring the extracellular electron transfer between the microbes and electrodes. Compared to the MFC with anode without any modification, that is, bare anode, the single chambered MFC with 20% H 2 O 2 modified anode exhibited excellent electro‐catalytic activity and a 91% decrease in the internal resistance (decreased from 35 ± 0.5 to 3.0 ± 0.6 kΩ) along with 89% increase in the maximum power density (increased from 8.8 ± 0.7 to 89.7 ± 0.6 mW/m 2 ). MFCs with 20% H 2 O 2 modified anode resulted in high decolorization efficiency of real dye wastewater (RDW) up to 92% which is 18% higher than that of the MFC with the bare anode. In order to boost the power output, the system was designed and studied by electrically stacking the 24 individual units of the MFC with the modified anode into parallel and series configurations. In parallel stacking and series stacking, the power output was 18.9 and 13.5 times higher than the single MFC unit, respectively. The RDW degradation rate was in the order of parallel stack > series stack > single MFC unit.

Qibin Li, Hong Liu

International Journal of Engineering and Technology • 2023

In southern China, where there is no district heating in residential buildings, the thermal comfort of indoor occupants cannot be guaranteed in winter due to the high energy consumption of whole-space heating. Foot Heating Pad (FHP), as a Personal Comfort System (PCS) device, enables occupants to improve thermal comfort with less cost. In this study, the effects of local heating by FHP on foot skin temperatures and thermal comfort were investigated, and the energy-efficiency performance of FHP was analyzed. A heat transfer model of human foot, which consists of four layers of body tissues, was established to simulate the foot temperatures under continuous and intermittent heating, and the numerical simulation of the model was accomplished using ANSYS. Besides, an FHP (36 W) based on Peltier heater was proposed and developed to heat the foot, and a climate chamber experiment involving 16 subjects was performed to collect subjects’ thermal comfort votes at three ambient temperature conditions of 8 °C, 11 °C, and 14 °C. The simulation results show that the foot skin temperature was significantly enhanced, and the plantar skin temperature increased by seven Temperature (K). Besides, there was no significant difference in foot temperature distribution between intermittent heating and continuous heating. However, the experimental results indicated that continuous heating was more effective in enhancing subjects’ thermal comfort and was able to ensure a neutral overall thermal sensation in a 14 °C environment. The Corrective Power (CP) of FHP was 7K and the Corrective Energy & Power (CEP) was 5.1W/K. This study is expected to provide guidance for the optimization design of PCS devices.

Keith Scott, Cassandro Murano

Journal of Chemical Technology & Biotechnology • 2006

Abstract The paper reports results of a mediatorless microbial fuel cell (MFC), utilising waste carbohydrate (manure) as a fuel, which did not use a catalyst or a proton exchange membrane and is thus environmentally friendly (by using no toxic substances) in treating waste. The cell used a manure sludge in the anode compartment and an aqueous salt solution (seawater) containing dissolved oxygen. The influence of the geometric position of the anode and cathode, both made of carbon cloth, had a major effect on the fuel cell power performance. The maximum power density obtained with the cell was 4.21 mW m −2 . The paper also reports results of a mediated MFC using a yogurt bacteria and methylene blue as mediator. This cell produced a maximum power density of over 13 mW m −2 . This power output compares quite favourably with that achieved with the same cell using glucose as fuel with E. coli (peak power density of 180 mW m −2 ). Copyright © 2007 Society of Chemical Industry

Neng Wu Zhu, Xi Chen, Li Xing Tu et al.

Advanced Materials Research • 2011

Stacking microbial fuel cells (MFCs) in series can provide higher voltage; however, voltage reversal (VR) adversely affects performance of the stacked MFCs. In this paper, diodes are introduced into three stacked MFCs so as to investigate the VR behavior and offer a diodes-based explanation of the VR. The results show that VR occurs in the different stacked MFCs systems. VR of the stacked MFCs connected with forward diodes (～0.37 V) happens in a similar pattern as that without diodes (～0.80 V). However, it only happens at the end of a cycle. This can be analyzed that the resistance of the diodes consume a part of the flowing electrons and the speed of potential changes of the electrodes slows down. Differently, in the stacked MFCs connected with reverse diodes, the voltages of each unit MFC approximately equal their open circuit voltages (～0.75 V), and VR happens in the unit MFC with reverse diodes at the cathode end only. It implies that the imbalanced consumption of electrons in unit MFCs and the potential changes of specific electrode directly result in VR.

, Mark Dondi Arboleda

Journal of Environmental Science and Management • 2017

The current Philippine energy crisis reminds us of the importance of finding alternative energy sources. Microbial fuel cells (MFC) may contribute to the solution. MFCs utilizing marine sediments, rice straw, domestic sewage, and agricultural water have a large potential as an alternative energy source. The objectives of the project were to isolate the biological agent, determine the optimum waste substrates, and to develop a working microbial fuel cell using locally available materials as fuel source. Soil, sediment, and corn stover were collected. An improvised MFC was constructed with two compartments for the anode and cathode sections separated by an agar plug (5% w/v). Each compartment had 750 ml capacities. Several combinations of materials were determined. Triplicates of each material-isolate combination were used to determine voltage, amperage, and Columbic output. Thirty percent fish farm sediments produced the highest voltage and amperage. This treatment was able to produce power for 7 to 25 days after MFC setup. Addition of ammonium sulfate in this setup reduced electrical output. Other treatments also produced power but were not as comparable. This study showed that utilizing wastes as substrate for MFCs is feasible and may have practical use.

Maria G. Savvidou, Pavlos K. Pandis, Diomi Mamma et al.

Energies • 2022

High-energy consumption globally has raised questions about the low environmentally friendly and high-cost processes used until now for energy production. Microbial fuel cells (MFCs) may support alternative more economically and environmentally favorable ways of bioenergy production based on their advantage of using waste. MFCs work as bio-electrochemical devices that consume organic substrates in order for the electrogenic bacteria and/or enzyme cultures to produce electricity and simultaneously lower the environmental hazardous value of waste such as COD. The utilization of organic waste as fuels in MFCs has opened a new research path for testing a variety of by-products from several industry sectors. This review presents several organic waste substrates that can be employed as fuels in MFCs for bioenergy generation and the effect of their usage on power density, COD (chemical oxygen demand) removal, and Coulombic efficiency enhancement. Moreover, a demonstration and comparison of the different types of mixed waste regarding their efficiency for energy generation via MFCs are presented. Future perspectives for manufacturing and cost analysis plans can support scale-up processes fulfilling waste-treatment efficiency and energy-output densities.

Osamu Ichihashi, Kayako Hirooka, Tatsuya Takeguchi et al.

ECS Meeting Abstracts • 2016

Microbial fuel cell is a device that can achieve wastewater treatment and power generation simultaneously. For the practical application of microbial fuel cell, development of alternative cathode catalyst for platinum is necessary. In this study, a kind of sodium cobalt oxide, NaCo 2 O 4 was investigated, because estimated cobalt reserve is 100 times higher than platinum, and its price is about one thousandth. Catalyst ink was prepared by mixing NaCo 2 O 4 powder with carbon black powder and Nafion dispersion. Then cathode was fabricated by applying the ink to PTFE treated carbon paper. Cathode with Pt catalyst and that with activated carbon (NORIT SX PLUS) were also prepared for comparison.ORR activity of the cathodes was measured by linear sweep voltammetry (LSV). Oxygen reduction reaction (ORR) activity of NaCo 2 O 4 cathode increased 15-25 times by the addition of carbon black as conductive assistant material in catalyst ink. Two kinds of carbon black were tested, and a cathode with Ketjen black showed better ORR activity than that with Vulcan XC-72. By increasing coating amount of catalyst ink from 2mg/cm 2 (NaCo 2 O 4 ) to 4mg/cm 2 , ORR activity increased 1.6 - 1.7 times, which was equivalent to 50-60% of Pt catalyst (Fig) . Gram based ORR activity of this catalyst was higher than that of activated carbon (NORIT SX PLUS) catalyst (Fig). The NaCo 2 O 4 cathode having highest ORR activity was built into a pre-acclimated MFC, and then used for the treatment of synthetic wastewater. The current density was about 3A/m 2 , which was a little lower than the value during the operation equipped with a Pt cathode (about 4A/m 2 ). However, any problems such as a decrease in electricity generation were not observed in several days of operation. Power density curve of the MFC equipped with the NaCo 2 O 4 cathode was obtained by the LSV measurement , and the maximum current density was 0.58 W/m 2 , which is about a half of the density achieved by a Pt cathode. Further research on the preparation condition of the cathode, such as the amount of conductive assistant material, the amount of binder, and the coating amounts of the catalyst ink, would probably contribute to further improve the cathode ORR activity, which would improve electricity generation performance of a MFC. Figure 1

Ganesh Chinnaraj, Gomathi Priya Ponnaiah

Chemical Engineering & Technology • 2021

Abstract The microbial fuel cell (MFC) is a device for wastewater treatment with simultaneous power generation. As batch‐mode MFCs are common, the present research work reports on two trials of continuous mode operation of MFCs using domestic wastewater as substrate and sludge as bacterial source. Trial‐2 was carried out with low substrate flow rate. The maximum chemical oxygen demand (COD) reduction during substrate treatment in trial‐1 and 2 was determined. Though the average power output was high in trial‐1, it had a drastically changing trend. Trial‐2 provided better water treatment and non‐fluctuating power output. Thus, it is favorable considering sustainable electricity generation.

Jinzhu Tan, Y. J. Chao, Woo-Kum Lee et al.

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

A Polymer Electrolyte Membrane (PEM) fuel cell stack requires elastomeric gaskets in each cell to keep the reactant gases within their respective regions. If any gasket degrades or fails, the reactant gases (O2 and H2) can leak overboard or mix with each other directly during operation or during standby, and affect the overall operation and performance of the fuel cell. The degradation of four commercial gasket materials was investigated in a simulated fuel cell environment in this study. In an effort towards predicting lifetime of fuel cells, two solutions and two temperatures were used in the short-term, accelerated aging tests. Bend-strip environment crack resistance tests were performed on samples with various bend angles. Weight loss was monitored and surface structure changes were examined using optical microscopy on the samples exposed to the simulated fuel cell environment for selected periods of time. Attenuated Total Reflection Fourier Transform Infrared (ATR-FTIR) spectroscopy was employed to study surface chemistry of the gasket materials before and after exposure to the simulated fuel cell environment over time. Stress and strain analysis was conducted using finite element method (FEM) to quantify the stress/state in test samples. The test results reveal that two silicone materials were degraded significantly while the other two did not show much degradation up to 42 weeks exposure to the simulated fuel cell environment. Optical microscopy and ATR-FTIR spectroscopy analysis indicate that the surface chemistry altered gradually via mechanisms involving de-cross linking and chain scission in the backbone. From experimental and numerical results, it is concluded that there is an interaction between chemistry and stress that appears to accelerate the degradation of the gasket materials in fuel cell environment.

Chetan Laddha

SPE Offshore Europe Conference & Exhibition • 2023

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

Masakazu Yoneda, Masato Takimoto

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

It is very important to understand the transport phenomena under various operating and structural conditions to achieve the high performance of Polymer Electrolyte Fuel Cell (PEFC). In this study, the effect of liquid water removal inside flow channel on the performance of a large-sized cell was investigated. To calculate the performance of a cell or stack, we developed a simulation tool with macroscopic models of MEA characteristics such as electrochemical kinetics, catalyst utilization, limiting current density, and two-phase transport inside the gas diffusion layer (GDL) and the flow channel. At first, we investigated the effect of wall contact angle and cross-section of flow channel on the liquid water removal by the Moving Particle Semi-implicit method and calculated the velocity ratio (liquid water velocity for gas velocity) inside the flow channel including the effect of mesoscopic structure of GDL. Applying this correlation to the two-phase model of the macroscopic PEFC simulation, we confirmed that the performance in the case of hydrophilic and shallow-shaped channel is much better in other case under low utilization operation.

Paolo Bombelli, Ross J. Dennis, Fabienne Felder et al.

Royal Society Open Science • 2016

Plant microbial fuel cells are a recently developed technology that exploits photosynthesis in vascular plants by harnessing solar energy and generating electrical power. In this study, the model moss species Physcomitrella patens , and other environmental samples of mosses, have been used to develop a non-vascular bryophyte microbial fuel cell (bryoMFC). A novel three-dimensional anodic matrix was successfully created and characterized and was further tested in a bryoMFC to determine the capacity of mosses to generate electrical power. The importance of anodophilic microorganisms in the bryoMFC was also determined. It was found that the non-sterile bryoMFCs operated with P. patens delivered over an order of magnitude higher peak power output (2.6 ± 0.6 µW m −2 ) than bryoMFCs kept in near-sterile conditions (0.2 ± 0.1 µW m −2 ). These results confirm the importance of the microbial populations for delivering electrons to the anode in a bryoMFC. When the bryoMFCs were operated with environmental samples of moss (non-sterile) the peak power output reached 6.7 ± 0.6 mW m −2 . The bryoMFCs operated with environmental samples of moss were able to power a commercial radio receiver or an environmental sensor (LCD desktop weather station).

So̸ren Juhl Andreasen, Rasmus Mosbæk, Jakob Rabjerg Vang et al.

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

This paper presents test results regarding the poisoning effects of CO and CO2 on H3PO4/Polybenzimidazole (PBI) membrane based high temperature proton exchange membrane fuel cell (HT-PEMFC). Electrochemical impedance spectroscopy (EIS), which is a non intrusive diagnostic tool for electrochemical systems, has been used to investigate these effects. A single cell test setup consisting of an electrically heated single cell assembly with a PEMEAS CELTEC P membrane electrode assembly (MEA) of an active area of 45cm2 and mass flow controllers for Air, H2, CO and CO2 was constructed in the laboratory. All operational parameters as well as data acquisition are controlled by two LabView programs, running on two separate computers. The impedance spectrum of the fuel cell is recorded at different operating points and then an Equivalent Circuit (EC), proposed for modelling the cell impedance, is fitted to the spectrum in order to analyze and quantify the impact of the individual factors on HT-PEMFC performance. Results showed that CO poisoning has an effect on all the losses monitored. Intermediate frequency resistances showed higher increase with increasing contamination and decreasing temperature than high frequency resistances, which is attributable to the adsorption of CO on Pt catalyst.

Najla Grioui, Amal Elleuch, Kamel Halouani et al.

C • 2023

In this study, exhausted olive pomace (EOP) biochar prepared by carbonization at 400 °C is investigated as a fuel in a direct carbon fuel cell (DCFC) with an electrolyte-supported configuration. The feasibility of using the EOP biochar in the DCFC is confirmed, showing a maximum power density of 10 mW·cm−2 at 700 °C. This limited DCFC performance is compared with other biochars prepared under similar conditions and interrelated with various biochar physico-chemical characteristics, as well as their impact on the DCFC’s chemical and electrochemical reaction mechanisms. A high ash content (21.55%) and a low volatile matter (40.62%) content of the EOP biochar are among the main causes of the DCFC’s limited output. Silica is the major impurity in the EOP biochar ash, which explains the limited cell performance as it causes low reactivity and limited electrical conductivity because of its non-crystal structure. The relatively poor DCFC performance when fueled by the EOP biochar can be overcome by further pre- and post-treatment of this renewable fuel.

Feng Ji, Linlin Yang, Yinhua Li et al.

Energy Science & Engineering • 2019

Abstract Internal reforming methanol fuel cell (IRMFC) has potential applications in portable or stationary power supply system, but currently performance of the IRMFC is limited by the low hydrogen production of its reformer. In order to produce more hydrogen with less volume, in this paper a single channel serpentine packed bed reformer was designed, and its bed size was optimized by experiment and numerical simulation to enhance heat transfer and increase catalyst utilization. It was found that with the bed diameter from 5.8 mm down to 3.8 mm, the reformer temperature distribution was more uniform but the bed pressure drop increased a lot. Considering performance and pressure drop, the reformer of 5 mm was optimal, per milliliters of which could supply 9.8 mL/min hydrogen at 453 K, almost twice as much as that by A. Mendes et al with one‐third of their catalyst loading. The reformer was quite stable, and less than 10% decline in methanol conversion was observed during the 100 hours period at 473 K. When incorporated into an IRMFC single cell, power density of the single cell reached 0.45‐0.55 W/cm 2 at 453‐473 K under CH 3 OH solution and air feed, the highest in existing reports. The main drawback has to do with low stability of the IRMFC single cell at high current density.

Hengyuan Liu, Qili Hu

Journal of Water Reuse and Desalination • 2022

Abstract Nitrate widely exists in water pollution and is the most stable form of nitrogen pollution. This study investigated the effect of the current density (CD) and the wheat-rice stone powder (WP) on denitrification performance, microbial diversity and enzyme activity in a bio-electrochemical reactor (BER). It was found that an optimum CD of 200 mA/m2 and the addition of WP significantly improved the nitrate removal rate constant compared with the control group (12.28 d−1 versus 9.75 d−1) and remarkably reduced the intermediate accumulation of nitrite. The application of both optimum CD and WP enhanced the microbial diversity and catalytic activity of nitrate reductase (Nar) and nitrite reductase (Nir). The most dominant microbial taxa in our reactor were Methyloversatilis, Methylotenera, and an unclassified genus of the family Methylophilaceae. Moreover, WP allowed the denitrifiers to better withstand the stress of high CD. This study presented results supporting the use of an optimum CD and natural mineral addition to improving the performance of the denitrification process within a BER.