Degradation mechanisms of sulfonated poly-aromatic membranes in fuel cell; Mecanismes de degradation des membranes polyaromatiques sulfonees en pile a combustible

Energy Technology Data Exchange (ETDEWEB)

Perrot, C

2006-11-15

Fuel cell development requires an improvement in the electrode-membrane assembly durability which depends on both the polymer used and the fuel cell operating conditions. The origin of the degradation can be either electrochemical, chemical and/or mechanical. This study deals with the understanding of alternative membranes ageing mechanisms, i.e. non fluorinated membranes, such as sPEEK and sPI. For this kind of membranes, the first process is chemical. Understanding these mechanisms is the first essential step to develop more stable structures. An original approach is developed to overcome the analytical difficulties encountered with polymers. It consists in studying the degradation mechanism on model structures. Ageing are carried out in water, with H{sub 2}O{sub 2} in some cases (identified as a cause of membrane chemical ageing in the fuel cell system), and at different temperatures. The approach consists in separating the different products formed by chromatography. Then they are identified (NMR, IR, MS) and quantified. This method allows us to establish the ageing mechanism. We show that the ageing of a sPEEK structure mainly results from an attack by end chains which spreads to the whole. This mechanism is confirmed on ex-situ and in-situ aged membranes. These two kinds of ageing lead to an important decrease in polymerisation degree (determined by SEC). Formation of the same degradation products is observed. In fuel cells, a heterogeneous degradation is noticed. It takes place mainly on the cathode side. sPI are known for their high sensitivity to hydrolysis. Nevertheless, we highlight a limited degradation at 80 Celsius degrees due to the recombination of hydrolyzed species at this temperature. (author)

Performance and long term degradation of 7 W micro-tubular solid oxide fuel cells for portable applications

Science.gov (United States)

Torrell, M.; Morata, A.; Kayser, P.; Kendall, M.; Kendall, K.; Tarancón, A.

2015-07-01

Micro-tubular SOFCs have shown an astonishing thermal shock resistance, many orders of magnitude larger than planar SOFCs, opening the possibility of being used in portable applications. However, only few studies have been devoted to study the degradation of large-area micro-tubular SOFCs. This work presents microstructural, electrochemical and long term degradation studies of single micro-tubular cells fabricated by high shear extrusion, operating in the intermediate range of temperatures (T∼700 °C). A maximum power of 7 W per cell has been measured in a wide range of fuel utilizations between 10% and 60% at 700 °C. A degradation rate of 360 mW/1000 h (8%) has been observed for cells operated over more than 1500 h under fuel utilizations of 40%. Higher fuel utilizations lead to strong degradations associated to nickel oxidation/reduction processes. Quick thermal cycling with heating ramp rates of 30 °C /min yielded degradation rates of 440 mW/100 cycles (9%). These reasonable values of degradation under continuous and thermal cycling operation approach the requirements for many portable applications including auxiliary power units or consumer electronics opening this typically forbidden market to the SOFC technology.

The Effect of Platinum Electrocatalyst on Membrane Degradation in Polymer Electrolyte Fuel Cells.

Science.gov (United States)

Bodner, Merit; Cermenek, Bernd; Rami, Mija; Hacker, Viktor

2015-12-08

Membrane degradation is a severe factor limiting the lifetime of polymer electrolyte fuel cells. Therefore, obtaining a deeper knowledge is fundamental in order to establish fuel cells as competitive product. A segmented single cell was operated under open circuit voltage with alternating relative humidity. The influence of the catalyst layer on membrane degradation was evaluated by measuring a membrane without electrodes and a membrane-electrode-assembly under identical conditions. After 100 h of accelerated stress testing the proton conductivity of membrane samples near the anode and cathode was investigated by means of ex situ electrochemical impedance spectroscopy. The membrane sample near the cathode inlet exhibited twofold lower membrane resistance and a resulting twofold higher proton conductivity than the membrane sample near the anode inlet. The results from the fluoride ion analysis have shown that the presence of platinum reduces the fluoride emission rate; which supports conclusions drawn from the literature.

Chromium related degradation of solid oxide fuel cells; Chrom-bezogene Degradation von Festoxid-Brennstoffzellen

Energy Technology Data Exchange (ETDEWEB)

Neumann, Anita

2011-05-04

Solid Oxide Fuel Cells (SOFCs) offer a high potential for application as an auxiliary power unit (APU) for heavy goods vehicles as well as combined heat and power (CHP) systems. SOFCs are especially attractive due to their high efficiencies and the use of different fuel types. However, optimization in terms of long term stability and costs are still necessary. This work characterized the degradation of SOFCs with lanthanum strontium manganite (LSM) cathodes under chromium influence. Galvanostatic cell tests were carried out at 800 C with operation times from 250 - 3000 h and variation of the chromium source and current density. The current densities of j = 0 (A)/(cm{sup 2}), j = 0,3 (A)/(cm{sup 2}) and j = 0,5 (A)/(cm{sup 2}) were applied. The high temperature ferritic alloy Crofer22APU was used as a chromium source. Variation of the chromium source was realized by coating the Crofer22APU insert with the chromium retention layer Mn{sub 3}O{sub 4} and the cathode contact layer LCC10. Cell degradation was analyzed with regard to cell voltage, current density and area specific resistance (ASR). Microstructural alterations of the cathode as well as chromium content and distribution across the cell were investigated after completion of the cell tests. For cells with a chromium source present and operation with a nonzero current density, the course of cell degradation was divided into three phases: a run-in, weak linear degradation and strong linear degradation. A decrease of the chromium release rate by means of different coatings stretched the course of degradation along the timescale. Strong degradation, which is characterized by a significant increase in ASR as well as a decrease of current density at the operating point, was only observed when a chromium source in the setup was comb ined with operation of the cell with a non-zero current density. Operation of the cell with a chromium source but no current density caused a degradation of current density at the

Microstructural degradation of Ni-YSZ anodes for solid oxide fuel cells

DEFF Research Database (Denmark)

Thydén, Karl Tor Sune

2008-01-01

-reforming catalysis. In the context of electrochemically tested and technologically relevant cells, the majority of the microstructural work is performed on a cell tested at 850°C under relatively severe conditions for 17,500 hours. It is demonstrated that the major Ni rearrangements take place at the interface...... are of technological relevance, it is difficult to identify the effect from isolated parameters such as temperature, fuel gas composition and polarization. Model studies of high temperature aged Ni-YSZ cermets are generally performed in atmospheres containing relatively low concentrations of H2O. In this work......, the microstructural degradation in both electrochemically longterm tested cells and high-temperature aged model materials are studied. Since Ni particle sintering / coarsening is attributed to be the major cause of anode degradation, this subject attains the primary focus. A large part of the work is focused...

Oxidative degradation of acid doped polybenzimidazole membranes and fuel cell durability in the presence of ferrous ions

DEFF Research Database (Denmark)

Liao, Jianhui; Yang, Jingshuai; Li, Qingfeng

2013-01-01

Phosphoric acid doped polybenzimidazole membranes have been explored as proton exchange membranes for high temperature polymer electrolyte membrane fuel cells. Long-term durability of the membrane is of critical concern and has been evaluated by accelerated degradation tests under Fenton conditions...... of the polymer. Fuel cell durability tests with contaminations of ferrous ions did show considerable performance degradation, however, primarily due to the catalyst deterioration rather than the membrane degradation........ In this study effects of phosphoric acid and ferrous ions were investigated by measurements of the weight loss, intrinsic viscosity and size exclusion chromatography (SEC) of the polymer membranes. Ferrous ions resulted in, as expected, catalytic formation of peroxide radicals and hence the accelerated polymer...

Catalyst Degradation in High Temperature Proton Exchange Membrane Fuel Cells Based on Acid Doped Polybenzimidazole Membranes

DEFF Research Database (Denmark)

Cleemann, Lars Nilausen; Buazar, F.; Li, Qingfeng

2013-01-01

and multi‐walled carbon nanotubes were used as supports for electrode catalysts and evaluated in accelerated durability tests under potential cycling at 150 °C. Measurements of open circuit voltage, area specific resistance and hydrogen permeation through the membrane were carried out, indicating little...... contribution of the membrane degradation to the performance losses during the potential cycling tests. As the major mechanism of the fuel cell performance degradation, the electrochemical active area of the cathodic catalysts showed a steady decrease in the cyclic voltammetric measurements, which was also......Degradation of carbon supported platinum catalysts is a major failure mode for the long term durability of high temperature proton exchange membrane fuel cells based on phosphoric acid doped polybenzimidazole membranes. With Vulcan carbon black as a reference, thermally treated carbon black...

Chemical degradation mechanisms of membranes for alkaline membrane fuel cells

Energy Technology Data Exchange (ETDEWEB)

Choe, Yoong-Kee [National Institute of Advanced Industrial Science and Technology, Umezono 1-1-1, Tsukuba (Japan); Henson, Neil J.; Kim, Yu Seung [Los Alamos National Laboratory, Los Alamos, NM (United States)

2015-12-31

Chemical degradation mechanisms of membranes for alkaline membrane fuel cells have been investigated using density functional theory (DFT). We have elucidated that the aryl-ether moiety of membranes is one of the weakest site against attack of hydroxide ions. The results of DFT calculations for hydroxide initiated aryl-ether cleavage indicated that the aryl-ether cleavage occurred prior to degradation of cationic functional group. Such a weak nature of the aryl-ether group arises from the electron deficiency of the aryl group as well as the low bond dissociation energy. The DFT results suggests that removal of the aryl-ether group in the membrane should enhance the stability of membranes under alkaline conditions. In fact, an ether fee poly(phenylene) membrane exhibits excellent stability against the attack from hydroxide ions.

Electrochemical AC impedance model of a solid oxide fuel cell and its application to diagnosis of multiple degradation modes

Energy Technology Data Exchange (ETDEWEB)

Gazzarri, J.I.; Kesler, O. [Department of Mechanical Engineering, University of British Columbia, 2054-6250 Applied Science Lane, Vancouver, BC V6T 1Z4 (Canada)

2007-05-01

A finite element model of the impact of diverse degradation mechanisms on the impedance spectrum of a solid oxide fuel cell is presented as a tool for degradation mode identification. Among the degradation mechanisms that cause electrode active area loss, the attention is focused on electrode delamination and uniformly distributed surface area loss, which were found to cause distinct and specific changes in the impedance spectrum. Degradation mechanisms resulting in uniformly distributed reactive surface area loss include sintering, sulphur poisoning, and possibly incipient coke formation at the anode, and chromium deposition at the cathode. Parametric studies reveal the extent and limits of applicability of the model and detectability of the different degradation modes, as well as the influence of different cell geometries on the change in impedance behaviour resulting from the loss of active area. It is expected that this technique could form the basis of a useful diagnostic tool for both solid oxide fuel cell developers and users. (author)

Role of dissolved oxygen on the degradation mechanism of Reactive Green 19 and electricity generation in photocatalytic fuel cell.

Science.gov (United States)

Lee, Sin-Li; Ho, Li-Ngee; Ong, Soon-An; Wong, Yee-Shian; Voon, Chun-Hong; Khalik, Wan Fadhilah; Yusoff, Nik Athirah; Nordin, Noradiba

2018-03-01

In this study, a membraneless photocatalytic fuel cell with zinc oxide loaded carbon photoanode and platinum loaded carbon cathode was constructed to investigate the impact of dissolved oxygen on the mechanism of dye degradation and electricity generation of photocatalytic fuel cell. The photocatalytic fuel cell with high and low aeration rate, no aeration and nitrogen purged were investigated, respectively. The degradation rate of diazo dye Reactive Green 19 and the electricity generation was enhanced in photocatalytic fuel cell with higher dissolved oxygen concentration. However, the photocatalytic fuel cell was still able to perform 37% of decolorization in a slow rate (k = 0.033 h -1 ) under extremely low dissolved oxygen concentration (approximately 0.2 mg L -1 ) when nitrogen gas was introduced into the fuel cell throughout the 8 h. However, the change of the UV-Vis spectrum indicates that the intermediates of the dye could not be mineralized under insufficient dissolved oxygen level. In the aspect of electricity generation, the maximum short circuit current (0.0041 mA cm -2 ) and power density (0.00028 mW cm -2 ) of the air purged photocatalytic fuel cell was obviously higher than that with nitrogen purging (0.0015 mA cm -2 and 0.00008 mW cm -2 ). Copyright © 2017 Elsevier Ltd. All rights reserved.

Microstructural degradation of Ni-YSZ anodes for solid oxide fuel cells

Energy Technology Data Exchange (ETDEWEB)

Thyden, K.

2008-03-15

Ni-YSZ cermets have been used as anode materials in SOFCs for more than 20 years. Despite this fact, the major cause of degradation within the Ni-YSZ anode, namely Ni sintering / coarsening, is still not fully understood. Even if microstructural studies of anodes in tested cells are of technological relevance, it is difficult to identify the effect from isolated parameters such as temperature, fuel gas composition and polarization. Model studies of high temperature aged Ni-YSZ cermets are generally performed in atmospheres containing relatively low concentrations of H2O. In this work, the microstructural degradation in both electrochemically longterm tested cells and high-temperature aged model materials are studied. Since Ni particle sintering / coarsening is attributed to be the major cause of anode degradation, this subject attains the primary focus. A large part of the work is focused on improving microstructural techniques and shows that the application of low acceleration voltages (<= 1 kV) in a FE-SEM makes it possible to obtain two useful types of contrast between the phases in Ni-YSZ composites. By changing between the ordinary lateral SE detector and the inlens detector, using similar microscope settings, two very different sample characteristics are probed: 1) The difference in secondary emission coefficient, delta, between the percolating and non-percolating Ni is maximized in the low-voltage range due to a high delta for the former and the suppression of delta by a positive charge for the latter. This difference yields a contrast between the two phases which is picked up by an inlens secondary electron detector. 2) The difference in backscatter coefficient, eta, between Ni and YSZ is shown to increase with decreasing voltage. The contrast is illustrated in images collected by the normal secondary detector since parts of the secondary signals are generated by backscattered electrons. High temperature aging experiments of model Ni-YSZ anode cermets show

Degradation of H₃PO₄/PBI High Temperature Polymer Electrolyte Membrane Fuel Cell under Stressed Operating Conditions

DEFF Research Database (Denmark)

Zhou, Fan

performance loss caused by CO poisoning can be alleviated by the presence of water vapor. The CO oxidation via the water gas shift reaction is the main reason for the mitigated CO poisoning with the presence of water vapor. Meanwhile, the CO poisoning can deteriorate with the presence of CO2, although the CO2...... for HT-PEM fuel cell based micro-CHP units for households, the daily startup/shutdown operation is necessary. Moreover, the faults in the H2 supply system or in controlling the reformer can cause the H2 starvation of the HT-PEM fuel cell. The effects of these operating conditions to the degradation...... results in the degradation in cell performance of the HT-PEM fuel cell by increasing the charge transfer resistance and mass transfer resistance. The CO with volume fraction of 1% – 3% can cause significant performance loss to the HT-PEM fuel cell at the operating temperature of 150 oC. The cell...

Study on hydrophobicity degradation of gas diffusion layer in proton exchange membrane fuel cells

International Nuclear Information System (INIS)

Yu, Shuchun; Li, Xiaojin; Li, Jin; Liu, Sa; Lu, Wangting; Shao, Zhigang; Yi, Baolian

2013-01-01

Highlights: • The hydrophobicity degradation mechanism of GDL was proposed thoroughly. • C-O and C=O groups appeared on the surfaces of GDL after immersion. • The relative content of PTFE in GDL decreased after immersion. • The surfaces and inner structure of GDL destroyed after immersion. - Abstract: As one of the essential components of proton exchange membrane fuel cell (PEMFC), gas diffusion layer (GDL) is of importance on water management, as well on the performance and durability of PEMFC. In this paper, the hydrophobicity degradation of GDL was investigated by immersing it in the 1.0 mol L −1 H 2 SO 4 solution saturated by air for 1200 h. From the measurements of contact angle and water permeability, the hydrophobic characteristics of the pristine and immersed GDLs were compared. To investigate the causes for hydrophobicity degradation, the GDLs were analyzed by scanning electron microscopy, X-ray photoelectron spectroscopy and thermogravimetry. Further, the chemical compositions of H 2 SO 4 solutions before and after immersion test were analyzed with infrared spectroscopy. Results showed that the hydrophobicity of immersed GDL decreased distinctly, which was caused by the damage of physical structure and surface characteristics. Moreover, the immersed GDL showed a worse fuel cell performance than the pristine GDL, especially under a low humidity condition

Methyl phosphate formation as a major degradation mode of direct methanol fuel cells with phosphoric acid based electrolytes

DEFF Research Database (Denmark)

Aili, David; Vassiliev, Anton; Jensen, Jens Oluf

2015-01-01

Phosphoric acid and phosphoric acid doped polymer membranes are widely used as electrolytes in hydrogen based fuel cells operating at elevated temperatures. Such electrolytes have been explored for direct oxidation of methanol to further increase the versatility of the systems, however......, with demonstrated lifetimes of only a few days to weeks. In this work the methyl phosphate formation from the acid and methanol is identified and proposed to be a major mechanism for the cell degradation. Proton conductivity and fuel cell durability tests validate the mechanism at high methanol contents....

Anodic deposition-assisted photoelectrocatalytic degradation of bisphenol A at a cadmium sulfide modified electrode based on visible light-driven fuel cells

International Nuclear Information System (INIS)

Luo, Jin-Yuan; Chen, Lin-Lin; Liang, Xing-Hui; Zhao, Qian-Wen; Li, Hong

2015-01-01

Highlights: • CdS nanoparticles can largely promote anodic deposition of BPA in the dark. • Photoelectrocatalytic degradation of BPA is driven by photo-stimulated fuel cells. • CdS/ITO is regenerated in photoelectrocatalytic degradation process of BPA. • Visible light-driven BPA fuel cell exhibits several unique advantages. - Abstract: A novel photoelectrocatalytic oxidation method has been successfully developed to effectively degrade bisphenol A (BPA) using a visible light-sensitive CdS nanoparticle modified indium-tin oxide (ITO) electrode. In the present protocol, BPA is oxidized on the CdS/ITO electrode to produce a redox-active film (BPA AD ), which is subsequently degraded upon incorporation of visible light irradiation and anodic electric fields, making the CdS/ITO electrode cyclically regenerated and the BPA removed. The addition of CdS nanoparticles to the ITO electrode not only increases the anodic deposition of BPA in the dark, but also promotes the photoelectrocatalytic degradation of BPA under visible light irradiation. The CdS/ITO photoanode shows high regeneration ability, and the removal efficiency of BPA is high up to 94.1%. Meanwhile, a monopolar visible light-simulated BPA fuel cell vs. Ag/AgCl electrode with a salt bridge is fabricated to achieve the photoelectrocatalytic degradation of BPA, showing open-circuit photovoltage of 0.412 (±0.015) V and short-circuit photocurrent density of 20.52 (±1.02) μA cm −2 , respectively. The present study provides a new approach for efficient removal of phenolic pollutants and optimum utilization of renewable energy sources.

Degradation modeling and operational optimization for improving the lifetime of high-temperature PEM (proton exchange membrane) fuel cells

International Nuclear Information System (INIS)

Kim, Jintae; Kim, Minjin; Kang, Taegon; Sohn, Young-Jun; Song, Taewon; Choi, Kyoung Hwan

2014-01-01

High-temperature PEMFCs (proton exchange membrane fuel cells) using PA (phosphoric acid)-doped PBI (polybenzimidazole) membranes have received attention as a potential solution to several of the issues with traditional low-temperature PEMFCs. However, the durability of high-temperature PEMFCs deteriorates rapidly with increasing temperature, although its performance improves. This characteristic makes it difficult to select the proper operating temperature to achieve its target lifetime. In this paper, to resolve this problem, models were developed to predict the performance and durability of the high-temperature PEMFC as a function of operating temperature. The optimal operating temperature was then determined for a variety of lifetimes. Theoretical model to estimate cell performance and empirical model to predict the degradation rate of cell performance were constructed, respectively. The prediction results of the developed models agreed well with the experimental data. From the simulation, we could obtain higher average cell performances by optimizing the operating temperature for the given target lifetime compared to the cell performance at some temperatures determined using an existing rule of thumb. It is expected that the proposed methodologies will lead to the more rapid commercialization of this technology in such applications as stationary and automotive fuel cell systems. - Highlights: • High-temperature PEMFCs (proton exchange membrane fuel cells). • Operational optimization for improving the lifetime. • Development of the degradation modeling for high-temperature PEMFCs

Highly durable, coking and sulfur tolerant, fuel-flexible protonic ceramic fuel cells.

Science.gov (United States)

Duan, Chuancheng; Kee, Robert J; Zhu, Huayang; Karakaya, Canan; Chen, Yachao; Ricote, Sandrine; Jarry, Angelique; Crumlin, Ethan J; Hook, David; Braun, Robert; Sullivan, Neal P; O'Hayre, Ryan

2018-05-01

Protonic ceramic fuel cells, like their higher-temperature solid-oxide fuel cell counterparts, can directly use both hydrogen and hydrocarbon fuels to produce electricity at potentially more than 50 per cent efficiency 1,2 . Most previous direct-hydrocarbon fuel cell research has focused on solid-oxide fuel cells based on oxygen-ion-conducting electrolytes, but carbon deposition (coking) and sulfur poisoning typically occur when such fuel cells are directly operated on hydrocarbon- and/or sulfur-containing fuels, resulting in severe performance degradation over time 3-6 . Despite studies suggesting good performance and anti-coking resistance in hydrocarbon-fuelled protonic ceramic fuel cells 2,7,8 , there have been no systematic studies of long-term durability. Here we present results from long-term testing of protonic ceramic fuel cells using a total of 11 different fuels (hydrogen, methane, domestic natural gas (with and without hydrogen sulfide), propane, n-butane, i-butane, iso-octane, methanol, ethanol and ammonia) at temperatures between 500 and 600 degrees Celsius. Several cells have been tested for over 6,000 hours, and we demonstrate excellent performance and exceptional durability (less than 1.5 per cent degradation per 1,000 hours in most cases) across all fuels without any modifications in the cell composition or architecture. Large fluctuations in temperature are tolerated, and coking is not observed even after thousands of hours of continuous operation. Finally, sulfur, a notorious poison for both low-temperature and high-temperature fuel cells, does not seem to affect the performance of protonic ceramic fuel cells when supplied at levels consistent with commercial fuels. The fuel flexibility and long-term durability demonstrated by the protonic ceramic fuel cell devices highlight the promise of this technology and its potential for commercial application.

Unraveling micro- and nanoscale degradation processes during operation of high-temperature polymer-electrolyte-membrane fuel cells

Science.gov (United States)

Hengge, K.; Heinzl, C.; Perchthaler, M.; Varley, D.; Lochner, T.; Scheu, C.

2017-10-01

The work in hand presents an electron microscopy based in-depth study of micro- and nanoscale degradation processes that take place during the operation of high-temperature polymer-electrolyte-membrane fuel cells (HT-PEMFCs). Carbon supported Pt particles were used as cathodic catalyst material and the bimetallic, carbon supported Pt/Ru system was applied as anode. As membrane, cross-linked polybenzimidazole was used. Scanning electron microscopy analysis of cross-sections of as-prepared and long-term operated membrane-electrode-assemblies revealed insight into micrometer scale degradation processes: operation-caused catalyst redistribution and thinning of the membrane and electrodes. Transmission electron microscopy investigations were performed to unravel the nanometer scale phenomena: a band of Pt and Pt/Ru nanoparticles was detected in the membrane adjacent to the cathode catalyst layer. Quantification of the elemental composition of several individual nanoparticles and the overall band area revealed that they stem from both anode and cathode catalyst layers. The results presented do not demonstrate any catastrophic failure but rather intermediate states during fuel cell operation and indications to proceed with targeted HT-PEMFC optimization.

Oxidative degradation of polybenzimidazole membranes as electrolytes for high temperature proton exchange membrane fuel cells

DEFF Research Database (Denmark)

Liao, J.H.; Li, Qingfeng; Rudbeck, H.C.

2011-01-01

the oxidative degradation of the polymer membrane was studied under the Fenton test conditions by the weight loss, intrinsic viscosity, size exclusion chromatography, scanning electron microscopy and Fourier transform infrared spectroscopy. During the Fenton test, significant weight losses depending...... on the initial molecular weight of the polymer were observed. At the same time, viscosity and SEC measurements revealed a steady decrease in molecular weight. The degradation of acid doped PBI membranes under Fenton test conditions is proposed to start by the attack of hydroxyl radicals at the carbon atom......Polybenzimidazole membranes imbibed with acid are emerging as a suitable electrolyte material for high-temperature polymer electrolyte fuel cells. The oxidative stability of polybenzimidazole has been identified as an important issue for the long-term durability of such cells. In this paper...

Phenomenology of BWR fuel assembly degradation

Science.gov (United States)

Kurata, Masaki; Barrachin, Marc; Haste, Tim; Steinbrueck, Martin

2018-03-01

Severe accidents occurred at the Fukushima-Daiichi Nuclear Power Station (FDNPS) which required an immediate re-examination of fuel degradation phenomenology. The present paper reviews the updated knowledge on the phenomenology of the fuel degradation, focusing mainly on the BWR fuel assembly degradation at the macroscopic scale and that of the individual interactions at the meso-scale. Oxidation of boron carbide (B4C) control rods potentially generates far larger amounts of heat and hydrogen under BWR accident conditions. All integral tests with B4C control rods or control blades have shown early failure, liquefaction, relocation and oxidation of B4C starting at temperatures around 1250 °C, well below the significant interaction temperatures of UO2-Zry. These interactions or reactions potentially influence the progress of fuel degradation in the early phase. The steam-starved conditions, which are being discussed as a likely scenario at the FDNPS accident, highly influence the individual interactions and potentially lead the fuel degradation in non-prototypical directions. The detailed phenomenology of individual interactions and their influence on the transient and on the late phase of the severe accidents are also discussed.

Regularization of the degradation behavior and working zone of proton exchange membrane fuel cells with a five-constant ideal cell as prototype

International Nuclear Information System (INIS)

Zhang, H.F.; Pei, P.C.; Yuan, X.; Chao, P.X.; Wang, X.Z.

2011-01-01

Highlights: → Load-oriented cell lifetime endpoint definition to reveal two forms of lifetime. → Working zone representing the range of optimum operating endpoint candidates. → Ideal cell model to describe the commonness in PEM fuel cell specialties. → Ideal cell as prototype to regularize real cells. → Working zone of real cells uniformly characterized with five cell constants. - Abstract: This paper is to outline the working zone (the correlative assembly of all the practical steady-state operating points under all affordable constant power loads) of proton exchange membrane (PEM) fuel cells in united form. For this purpose, an ideal cell model is proposed to regularize the degradation behavior of real cells, and a load-oriented cell lifetime endpoint definition is made to reveal two forms of cell lifetime. As derived, the working zone of any cell is an enclosed region by three boundaries: one part of the initial steady-state polarization (SSP) curve, the lifetime end-curve and the zero current density line; and the ideal cell has three distinct shapes of working zone of the simplest expressions of lifetime end-curve. Practical data well support the ideal cell as a good prototype for the regularization, and thus the working zone of real cells can be approximately but uniformly and concisely outlined, with the boundaries characterized with five cell constants including two initial SSP constants, two degradation constants and the absolute lifetime.

Investigation of electrolyte leaching in the performance degradation of phosphoric acid-doped polybenzimidazole membrane-based high temperature fuel cells

Science.gov (United States)

Jeong, Yeon Hun; Oh, Kyeongmin; Ahn, Sungha; Kim, Na Young; Byeon, Ayeong; Park, Hee-Young; Lee, So Young; Park, Hyun S.; Yoo, Sung Jong; Jang, Jong Hyun; Kim, Hyoung-Juhn; Ju, Hyunchul; Kim, Jin Young

2017-09-01

Precise monitoring of electrolyte leaching in high-temperature polymer electrolyte membrane fuel cell (HT-PEMFC) devices during lifetime tests is helpful in making a diagnosis of their quality changes and analyzing their electrochemical performance degradation. Here, we investigate electrolyte leaching in the performance degradation of phosphoric acid (PA)-doped polybenzimidazole (PBI) membrane-based HT-PEMFCs. We first perform quantitative analyses to measure PA leakage during cell operation by spectrophotometric means, and a higher PA leakage rate is detected when the current density is elevated in the cell. Second, long-term degradation tests under various current densities of the cells and electrochemical impedance spectroscopy (EIS) analysis are performed to examine the influence of PA loss on the membrane and electrodes during cell performance degradation. The combined results indicate that PA leakage affect cell performance durability, mostly due to an increase in charge transfer resistance and a decrease in the electrochemical surface area (ECSA) of the electrodes. Additionally, a three-dimensional (3-D) HT-PEMFC model is applied to a real-scale experimental cell, and is successfully validated against the polarization curves measured during various long-term experiments. The simulation results highlight that the PA loss from the cathode catalyst layer (CL) is a significant contributor to overall performance degradation.

Effect of inlet fuel type on the degradation of Ni/YSZ anode of solid oxide fuel cell by carbon deposition

Directory of Open Access Journals (Sweden)

Suttichai Assabumrungrat

2006-11-01

Full Text Available According to the high operating temperature of Solid Oxide Fuel Cell (SOFC (700-1100ºC, it is known that some hydrocarbon fuels can be directly used as inlet fuel instead of hydrogen by feeding straight to the anode. This operation is called a direct internal reforming SOFC (DIR-SOFC. However, the major difficulty of this operation is the possible degradation of anode by the carbon deposition, as the carbon species are easily formed. In the present work, the effect of inlet fuel (i.e. H2, synthesis gas (H2+CO, CH4, CH4+H2O, CH3OH+H2O, and C2H5OH+H2O on the degradation of nickel cermet (Ni/YSZ, which is the most common anode material of SOFC, was studied.It was found from the work that hydrogen and synthesis gas (CO+H2 are proper to be used as direct inlet fuels for DIR-SOFC with Ni/YSZ anode, since the carbon formation on Ni/YSZ occurred in the small quantity. The mixture of methane and steam (CH4+H2O can also be used as the inlet feed, but the H2O/CH4 ratio plays an important role. In contrast, pure methane (CH4, methanol with steam (CH3OH+H2O and ethanol with steam (C2H5OH+H2O are not suitable for using as direct inlet fuel for DIR-SOFC with Ni/YSZ anode even the higher H2O/CH3OH and H2O/C2H5OH ratios were applied.

In situ fluorescence spectroscopy correlates ionomer degradation to reactive oxygen species generation in an operating fuel cell.

Science.gov (United States)

Prabhakaran, Venkateshkumar; Arges, Christopher G; Ramani, Vijay

2013-11-21

The rate of generation of reactive oxygen species (ROS) within the polymer electrolyte membrane (PEM) of an operating proton exchange member fuel cell (PEMFC) was monitored using in situ fluorescence spectroscopy. A modified barrier layer was introduced between the PEM and the electrocatalyst layer to eliminate metal-dye interactions and fluorescence resonance energy transfer (FRET) effects during measurements. Standard fuel cell operating parameters (temperature, relative humidity, and electrode potential) were systematically varied to evaluate their influence on the rate of ROS generation during PEMFC operation. Independently, the macroscopic rate of PEM degradation was measured by monitoring the fluoride ion emission rate (FER) in the effluent stream at each operating condition. The ROS generation reaction rate constant (estimated from the in situ fluorescence experiments) correlated perfectly with the measured FER across all conditions, demonstrating unequivocally for the first time that a direct correlation exists between in situ ROS generation and PEM macroscopic degradation. The activation energy for ROS generation within the PEM was estimated to be 12.5 kJ mol(-1).

Fiscal 1994 survey report. Survey of factors causing degradation of phosphoric acid fuel cells; 1994 nendo rinsangata nenryo denchi no cell rekka yoin chosa hokokusho

Energy Technology Data Exchange (ETDEWEB)

NONE

1995-03-01

This survey aims to effectively promote studies for evaluating phosphoric acid fuel cell degradation. Data of time-dependent changes in voltage are collected from 58 plants now in operation (for 17,500 hours at the maximum). Half of them exhibit a degradation rate of 0.25-1%/1000 hours while degradation is abruptly accelerated midway in the other half. Causes for voltage drop are not known clearly. Since but a little systematically collected test data are available concerning the mechanism of cell degradation, it is decided that tests be conducted using small test model cells sharing the same specifications. Primary test conditions (combination of temperature, current, and pressure with test reference levels), performance evaluating methods (conditions of data collection), and methods of investigation by dismantling (items and frequency of investigations) are determined, and guidelines are provided for element tests for complementing the said test items and for studying their relations with the degradation mechanism. Based on acceleration-related factors to be obtained by common specification test cells, corporations involved will develop their own accelerated test methods. Small cells are fabricated for testing parameters, and model cells are specified. (NEDO)

Short stack modeling of degradation in solid oxide fuel cells. Part II. Sensitivity and interaction analysis

Science.gov (United States)

Gazzarri, J. I.; Kesler, O.

In the first part of this two-paper series, we presented a numerical model of the impedance behaviour of a solid oxide fuel cell (SOFC) aimed at simulating the change in the impedance spectrum induced by contact degradation at the interconnect-electrode, and at the electrode-electrolyte interfaces. The purpose of that investigation was to develop a non-invasive diagnostic technique to identify degradation modes in situ. In the present paper, we appraise the predictive capabilities of the proposed method in terms of its robustness to uncertainties in the input parameters, many of which are very difficult to measure independently. We applied this technique to the degradation modes simulated in Part I, in addition to anode sulfur poisoning. Electrode delamination showed the highest robustness to input parameter variations, followed by interconnect oxidation and interconnect detachment. The most sensitive degradation mode was sulfur poisoning, due to strong parameter interactions. In addition, we simulate several simultaneous two-degradation-mode scenarios, assessing the method's capabilities and limitations for the prediction of electrochemical behaviour of SOFC's undergoing multiple simultaneous degradation modes.

Short stack modeling of degradation in solid oxide fuel cells. Part II. Sensitivity and interaction analysis

Energy Technology Data Exchange (ETDEWEB)

Gazzarri, J.I. [Department of Mechanical Engineering, University of British Columbia, 2054-6250 Applied Science Lane, Vancouver, BC V6T 1Z4 (Canada); Kesler, O. [Department of Mechanical and Industrial Engineering, University of Toronto, 5 King' s College Road, Toronto, ON M5S 3G8 (Canada)

2008-01-21

In the first part of this two-paper series, we presented a numerical model of the impedance behaviour of a solid oxide fuel cell (SOFC) aimed at simulating the change in the impedance spectrum induced by contact degradation at the interconnect-electrode, and at the electrode-electrolyte interfaces. The purpose of that investigation was to develop a non-invasive diagnostic technique to identify degradation modes in situ. In the present paper, we appraise the predictive capabilities of the proposed method in terms of its robustness to uncertainties in the input parameters, many of which are very difficult to measure independently. We applied this technique to the degradation modes simulated in Part I, in addition to anode sulfur poisoning. Electrode delamination showed the highest robustness to input parameter variations, followed by interconnect oxidation and interconnect detachment. The most sensitive degradation mode was sulfur poisoning, due to strong parameter interactions. In addition, we simulate several simultaneous two-degradation-mode scenarios, assessing the method's capabilities and limitations for the prediction of electrochemical behaviour of SOFC's undergoing multiple simultaneous degradation modes. (author)

Increasing the lifetime of fuel cell catalysts

NARCIS (Netherlands)

Latsuzbaia, R.

2015-01-01

In this thesis, I discuss a novel idea of fuel cell catalyst regeneration to increase lifetime of the PEM fuel cell electrode/catalyst operation and, therefore, reduce the catalyst costs. As many of the catalyst degradation mechanisms are difficult to avoid, the regeneration is alternative option to

Arrangement of fuel cell system for TNRF

International Nuclear Information System (INIS)

Nojima, Takehiro; Yasuda, Ryo; Iikura, Hiroshi; Sakai, Takuro; Matsubayashi, Masahito; Takenaka, Nobuyuki; Hayashida, Hirotoshi

2012-02-01

Polymer electrolyte fuel cells (fuel cells) can be potentially employed as sources of clean energy because they discharge only water as by-products. Fuel cells generate electricity with supply of oxygen and hydrogen gases. However, the water produced by the fuel cells blocks the gas supply, thereby degrading their performances. Therefore, it is important to understand the behavior of the water produced by the fuel cells in order to facilitate their development. Neutron radiography is a useful tool for visualizing the distribution of water in fuel cells. We have designed fuel cell operation system for TNRF (Thermal Neutron Radiography Facility) at JRR-3. The fuel cell operation system consists of various components such as gas flow and humidification systems, hydrogen-diluting system, purge system, and safety system for hydrogen gas. We tested this system using a Japan Automobile Research Institute (JARI) standard cell. The system performed stably and efficiently. In addition, neutron radiography tests were carried out to visualize the water distribution. The water produced by the fuel cell was observed during the fuel cell operation. (author)

Review: Durability and degradation issues of PEM fuel cell components

NARCIS (Netherlands)

Bruijn, de F.A.; Dam, V.A.T.; Janssen, G.J.M.

2008-01-01

Besides cost reduction, durability is the most important issue to be solved before commercialisation of PEM Fuel Cells can be successful. For a fuel cell operating under constant load conditions, at a relative humidity close to 100% and at a temperature of maximum 75 °C, using optimal stack and flow

The next generation fuel cells: anion exchange membrane fuel cells (AEMFC)

International Nuclear Information System (INIS)

Tauqir, A.; Zahoor, S.

2013-01-01

Many environmentally friendly alternatives (solar, wind, hydroelectric, and geothermal power) can only be used in particular environments. In contrast, fuel cells can have near-zero emissions, are quiet and efficient, and can work in any environment where the temperature is lower than the cell's operating temperature. Among various types of fuel cells, the AEMFC is the most recent one and has advantages such as excellent performance compared to other candidate fuel cells due to its active O/sub 2/ electrode kinetics and flexibility to use a wide range of electro-catalysts such as silver and nickels contrary to expensive one (Platinum) required for proton exchange membrane fuel cell (PEMFC). Anion exchange membrane (AEM) is a crucial part in AEMFC, determining durability and electrochemical performances of membrane electrode assembly (MEA). The role of an AEM is to conduct hydroxyl ions from cathode to anode. If this conduction is not sufficiently high and selective, the corresponding fuel cell will not find any practical application. One of the major problems associated with AEMFC is much lower conductivities of anion compare to proton conductivity in PEMFCs, even upon similar working condition. Thus AEMs is only practical, if it is chemically and mechanically stable against severe basic operation conditions and highly hydroxyl ions conductive. The conventional AEMs based on animated aliphatic and aromatic hydrocarbon or even fluorinated polymers tend to be attacked by hydroxyl ions, causing the degradation during operation is strongly basic conditions. (author)

End of project report on degradation processes in hydrogen fuel cells.

Science.gov (United States)

2008-01-01

Proton exchange membrane (PEM) fuel cells are one of the most popular types of fuel cells. They operate similarly to others with the electrolyte material inbetween the electrodes being a patented polymer called Nafion, made by DuPont. This polyelec...

Durability of PEM Fuel Cell Membranes

Science.gov (United States)

Huang, Xinyu; Reifsnider, Ken

Durability is still a critical limiting factor for the commercialization of polymer electrolyte membrane (PEM) fuel cells, a leading energy conversion technology for powering future hydrogen fueled automobiles, backup power systems (e.g., for base transceiver station of cellular networks), portable electronic devices, etc. Ionic conducting polymer (ionomer) electrolyte membranes are the critical enabling materials for the PEM fuel cells. They are also widely used as the central functional elements in hydrogen generation (e.g., electrolyzers), membrane cell for chlor-alkali production, etc. A perfluorosulfonic acid (PFSA) polymer with the trade name Nafion® developed by DuPont™ is the most widely used PEM in chlor-alkali cells and PEM fuel cells. Similar PFSA membranes have been developed by Dow Chemical, Asahi Glass, and lately Solvay Solexis. Frequently, such membranes serve the dual function of reactant separation and selective ionic conduction between two otherwise separate compartments. For some applications, the compromise of the "separation" function via the degradation and mechanical failure of the electrolyte membrane can be the life-limiting factor; this is particularly the case for PEM in hydrogen/oxygen fuel cells.

Bio-Electron-Fenton (BEF) process driven by microbial fuel cells for triphenyltin chloride (TPTC) degradation

International Nuclear Information System (INIS)

Yong, Xiao-Yu; Gu, Dong-Yan; Wu, Yuan-Dong; Yan, Zhi-Ying; Zhou, Jun; Wu, Xia-Yuan; Wei, Ping; Jia, Hong-Hua; Zheng, Tao; Yong, Yang-Chun

2017-01-01

Graphical abstract: Schematic diagram of the Bio-Electron-Fenton (BEF) process for TPTC degradation. - Highlights: • A Bio-Electro-Fenton process was performed for TPTC degradation. • TPTC removal efficiency achieved 78.32 ± 2.07% within 100 h. • The TPTC degradation rate (0.775 ± 0.021 μmol L"−"1 h"−"1) was much higher than previous reports. - Abstract: The intensive use of triphenyltin chloride (TPTC) has caused serious environmental pollution. In this study, an effective method for TPTC degradation was proposed based on the Bio-Electron-Fenton process in microbial fuel cells (MFCs). The maximum voltage of the MFC with graphite felt as electrode was 278.47% higher than that of carbon cloth. The electricity generated by MFC can be used for in situ generation of H_2O_2 to a maximum of 135.96 μmol L"−"1 at the Fe@Fe_2O_3_(_*_)/graphite felt composite cathode, which further reacted with leached Fe"2"+ to produce hydroxyl radicals. While 100 μmol L"−"1 TPTC was added to the cathodic chamber, the degradation efficiency of TPTC reached 78.32 ± 2.07%, with a rate of 0.775 ± 0.021 μmol L"−"1 h"−"1. This Bio-Electron-Fenton driving TPTC degradation might involve in Sn−C bonds breaking and the main process is probably a stepwise dephenylation until the formation of inorganic tin and CO_2. This study provides an energy saving and efficient approach for TPTC degradation.

Tutorial review of spent-fuel degradation mechanisms under dry-storage conditions

International Nuclear Information System (INIS)

Einziger, R.E.

1983-02-01

This tutorial reviews our present understanding of fuel-rod degradation over a range of possible dry-storage environments. Three areas are covered: (1) why study fuel-rod degradation; (2) cladding-degradation mechanisms; and (3) the status of fuel-oxidation studies

Fuel Cell Power Plant Initiative. Volume 1; Solid Oxide Fuel Cell/Logistics Fuel Processor 27 kWe Power System Demonstration for ARPA

Science.gov (United States)

Veyo, S.E.

1997-01-01

This report describes the successful testing of a 27 kWe Solid Oxide Fuel Cell (SOFC) generator fueled by natural gas and/or a fuel gas produced by a brassboard logistics fuel preprocessor (LFP). The test period began on May 24, 1995 and ended on February 26, 1996 with the successful completion of all program requirements and objectives. During this time period, this power system produced 118.2 MWh of electric power. No degradation of the generator's performance was measured after 5582 accumulated hours of operation on these fuels: local natural gas - 3261 hours, jet fuel reformate gas - 766 hours, and diesel fuel reformate gas - 1555 hours. This SOFC generator was thermally cycled from full operating temperature to room temperature and back to operating temperature six times, because of failures of support system components and the occasional loss of test site power, without measurable cell degradation. Numerous outages of the LFP did not interrupt the generator's operation because the fuel control system quickly switched to local natural gas when an alarm indicated that the LFP reformate fuel supply had been interrupted. The report presents the measured electrical performance of the generator on all three fuel types and notes the small differences due to fuel type. Operational difficulties due to component failures are well documented even though they did not affect the overall excellent performance of this SOFC power generator. The final two appendices describe in detail the LFP design and the operating history of the tested brassboard LFP.

Materials testing for molten carbonate fuel cells

International Nuclear Information System (INIS)

Di Mario, F.; Frangini, S.

1995-01-01

Unlike conventional generation systems fuel cells use an electrochemical reaction between a fossil fuel and an oxidant to produce electricity through a flame less combustion process. As a result, fuel cells offer interesting technical and operating advantages in terms of conversion efficiencies and environmental benefits due to very low pollutant emissions. Among the different kinds of fuel cells the molten carbonate fuel cells are currently being developed for building compact power generation plants to serve mainly in congested urban areas in virtue of their higher efficiency capabilities at either partial and full loads, good response to power peak loads, fuel flexibility, modularity and, potentially, cost-effectiveness. Starting from an analysis of the most important degradative aspects of the corrosion of the separator plate, the main purpose of this communication is to present the state of the technology in the field of corrosion control of the separator plate in order to extend the useful lifetime of the construction materials to the project goal of 40,000 hours

Bio-Electron-Fenton (BEF) process driven by microbial fuel cells for triphenyltin chloride (TPTC) degradation

Energy Technology Data Exchange (ETDEWEB)

Yong, Xiao-Yu; Gu, Dong-Yan; Wu, Yuan-Dong [College of Biotechnology and Pharmaceutical Engineering, Nanjing TECH University, Nanjing 211816 (China); Bioenergy Research Institute, Nanjing TECH University, Nanjing 211816 (China); Yan, Zhi-Ying [Key Laboratory of Environmental and Applied Microbiology, Environmental Microbiology, Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Science, Chengdu 610041 (China); Zhou, Jun; Wu, Xia-Yuan [College of Biotechnology and Pharmaceutical Engineering, Nanjing TECH University, Nanjing 211816 (China); Bioenergy Research Institute, Nanjing TECH University, Nanjing 211816 (China); Wei, Ping [College of Biotechnology and Pharmaceutical Engineering, Nanjing TECH University, Nanjing 211816 (China); Jia, Hong-Hua [College of Biotechnology and Pharmaceutical Engineering, Nanjing TECH University, Nanjing 211816 (China); Bioenergy Research Institute, Nanjing TECH University, Nanjing 211816 (China); Zheng, Tao, E-mail: zhengtao@ms.giec.ac.cn [Guangzhou Institute of Energy Conversion, Chinese Academy of Science, Nengyuan Road, Guangzhou 510640 (China); Yong, Yang-Chun, E-mail: ycyong@ujs.edu.cn [Biofuels Institute, School of the Environment, Jiangsu University, Zhenjiang 212013 (China); Jiangsu Key Laboratory of Chemical Pollution Control and Resources Reuse, Nanjing University of Science and Technology, Nanjing 210094 (China)

2017-02-15

Graphical abstract: Schematic diagram of the Bio-Electron-Fenton (BEF) process for TPTC degradation. - Highlights: • A Bio-Electro-Fenton process was performed for TPTC degradation. • TPTC removal efficiency achieved 78.32 ± 2.07% within 100 h. • The TPTC degradation rate (0.775 ± 0.021 μmol L{sup −1} h{sup −1}) was much higher than previous reports. - Abstract: The intensive use of triphenyltin chloride (TPTC) has caused serious environmental pollution. In this study, an effective method for TPTC degradation was proposed based on the Bio-Electron-Fenton process in microbial fuel cells (MFCs). The maximum voltage of the MFC with graphite felt as electrode was 278.47% higher than that of carbon cloth. The electricity generated by MFC can be used for in situ generation of H{sub 2}O{sub 2} to a maximum of 135.96 μmol L{sup −1} at the Fe@Fe{sub 2}O{sub 3(*)}/graphite felt composite cathode, which further reacted with leached Fe{sup 2+} to produce hydroxyl radicals. While 100 μmol L{sup −1} TPTC was added to the cathodic chamber, the degradation efficiency of TPTC reached 78.32 ± 2.07%, with a rate of 0.775 ± 0.021 μmol L{sup −1} h{sup −1}. This Bio-Electron-Fenton driving TPTC degradation might involve in Sn−C bonds breaking and the main process is probably a stepwise dephenylation until the formation of inorganic tin and CO{sub 2}. This study provides an energy saving and efficient approach for TPTC degradation.

Stimulated-healing of proton exchange membrane fuel cell catalyst

NARCIS (Netherlands)

Latsuzbaia, R.; Negro, E.; Koper, G.J.M.

2013-01-01

Platinum nanoparticles, which are used as catalysts in Proton Exchange Membrane Fuel Cells (PEMFC), tend to degrade after long-term operation. We discriminate the following mechanisms of the degradation: poisoning, migration and coalescence, dissolution, and electrochemical Ostwald ripening. There

Materials Challenges for Automotive PEM Fuel Cells

Science.gov (United States)

Gasteiger, Hubert

2004-03-01

Over the past few years, significant R efforts aimed at meeting the challenging cost and performance targets required for the use of Polymer Electrolyte Membrane (PEM) fuel cells in automotive applications. Besides engineering advances in bipolar plate materials and design, the optimization of membrane-electrode assemblies (MEAs) was an important enabler in reducing the cost and performance gaps towards commercial viability for the automotive market. On the one hand, platinum loadings were reduced from several mgPt/cm2MEA [1] to values of 0.5-0.6 mgPt/cm2MEA in current applications and loadings as low as 0.25 mgPt/cm2MEA have been demonstrated on the research level [2]. On the other hand, implementation of thin membranes (20-30 micrometer) [3, 4] as well as improvements in diffusion medium materials, essentially doubled the achievable power density of MEAs to ca. 0.9 W/cm2MEA (at 0.65 V) [5], thereby not only reducing the size of a PEMFC fuel cell system, but also reducing its overall materials cost (controlled to a large extent by membrane and Pt-catalyst cost). While this demonstrated a clear path towards automotive applications, a renewed focus of R efforts is now required to develop materials and fundamental materials understanding to assure long-term durability of PEM fuel cells. This presentation therefore will discuss the state-of-the-art knowledge of catalyst, catalyst-support, and membrane degradation mechanisms. In the area of Pt-catalysts, experience with phosphoric acid fuel cells (PAFCs) has shown that platinum sintering leads to long-term performance losses [6]. While this is less critical at the lower PEMFC operating temperatures (200C), very little is known about the dependence of Pt-sintering on temperature, cell voltage, and catalyst type (i.e., Pt versus Pt-alloys) and will be discussed here. Similarly, carbon-support corrosion can contribute significantly to voltage degradation in PAFCs [7], and even in the PEMFC environment more corrosion

3D Analysis of Fuel Cell Electrocatalyst Degradation on Alternate Carbon Supports.

Science.gov (United States)

Sneed, Brian T; Cullen, David A; Reeves, Kimberly S; Dyck, Ondrej E; Langlois, David A; Mukundan, Rangachary; Borup, Rodney L; More, Karren L

2017-09-06

Understanding the mechanisms associated with Pt/C electrocatalyst degradation in proton exchange membrane fuel cell (PEMFC) cathodes is critical for the future development of higher-performing materials; however, there is a lack of information regarding Pt coarsening under PEMFC operating conditions within the cathode catalyst layer. We report a direct and quantitative 3D study of Pt dispersions on carbon supports (high surface area carbon (HSAC), Vulcan XC-72, and graphitized carbon) with varied surface areas, graphitic character, and Pt loadings ranging from 5 to 40 wt %. This is accomplished both before and after catalyst-cycling accelerated stress tests (ASTs) through observations of the cathode catalyst layer of membrane electrode assemblies. Electron tomography results show Pt nanoparticle agglomeration occurs predominantly at junctions and edges of aggregated graphitized carbon particles, leading to poor Pt dispersion in the as-prepared catalysts and increased coalescence during ASTs. Tomographic reconstructions of Pt/HSAC show much better initial Pt dispersions, less agglomeration, and less coarsening during ASTs in the cathode. However, a large loss of the electrochemically active surface area (ECSA) is still observed and is attributed to accelerated Pt dissolution and nanoparticle coalescence. Furthermore, a strong correlation between Pt particle/agglomerate size and measured ECSA is established and is proposed as a more useful metric than average crystallite size in predicting degradation behavior across different catalyst systems.

Acid Distribution and Durability of HT-PEM Fuel Cells with Different Electrode Supports

DEFF Research Database (Denmark)

Kannan, A.; Li, Q.; Cleemann, L. N.

2018-01-01

made from carbon black took up much more acid than materials with a more coarse apparent structure made from graphitized carbon. The same trend was evident from thermally accelerated fuel cell tests at 180 °C under constant load where degradation rates depended strongly on the choice of GDL material......, especially on the cathode side. Acid was collected from the fuel cell exhaust at rates clearly correlated to the fuel cell degradation rates, but amounted to less than 6% of the total acid content in the cell even after significant degradation. Long-term durability of more than 5,500 h with a degradation...... long-term operation. The effect of the gas diffusion layers (GDL) on acid loss was studied. Four different commercially available GDLs were subjected to passive ex situ acid uptake by capillary forces and the acid distribution mapped over the cross-section. Materials with an apparent fine structure...

Improved Accelerated Stress Tests Based on Fuel Cell Vehicle Data

Energy Technology Data Exchange (ETDEWEB)

Patterson, Timothy [Research Engineer; Motupally, Sathya [Research Engineer

2012-06-01

UTC will led a top-tier team of industry and national laboratory participants to update and improve DOE’s Accelerated Stress Tests (AST’s) for hydrogen fuel cells. This in-depth investigation will focused on critical fuel cell components (e.g. membrane electrode assemblies - MEA) whose durability represented barriers for widespread commercialization of hydrogen fuel cell technology. UTC had access to MEA materials that had accrued significant load time under real-world conditions in PureMotion® 120 power plant used in transit buses. These materials are referred to as end-of-life (EOL) components in the rest of this document. Advanced characterization techniques were used to evaluate degradation mode progress using these critical cell components extracted from both bus power plants and corresponding materials tested using the DOE AST’s. These techniques were applied to samples at beginning-of-life (BOL) to serve as a baseline. These comparisons advised the progress of the various failure modes that these critical components were subjected to, such as membrane degradation, catalyst support corrosion, platinum group metal dissolution, and others. Gaps in the existing ASTs predicted the degradation observed in the field in terms of these modes were outlined. Using the gaps, new AST’s were recommended and tested to better reflect the degradation modes seen in field operation. Also, BOL components were degraded in a test vehicle at UTC designed to accelerate the bus field operation.

Degradation of graphene coated copper in simulated proton exchange membrane fuel cell environment: Electrochemical impedance spectroscopy study

Science.gov (United States)

Ren, Y. J.; Anisur, M. R.; Qiu, W.; He, J. J.; Al-Saadi, S.; Singh Raman, R. K.

2017-09-01

Metallic materials are most suitable for bipolar plates of proton exchange membrane fuel cell (PEMFC) because they possess the required mechanical strength, durability, gas impermeability, acceptable cost and are suitable for mass production. However, metallic bipolar plates are prone to corrosion or they can passivate under PEMFC environment and interrupt the fuel cell operation. Therefore, it is highly attractive to develop corrosion resistance coating that is also highly conductive. Graphene fits these criteria. Graphene coating is developed on copper by chemical vapor deposition (CVD) with an aim to improving corrosion resistance of copper under PEMFC condition. The Raman Spectroscopy shows the graphene coating to be multilayered. The electrochemical degradation of graphene coated copper is investigated by electrochemical impedance spectroscopy (EIS) in 0.5 M H2SO4 solution at room temperature. After exposure to the electrolyte for up to 720 h, the charge transfer resistance (Rt) of the graphene coated copper is ∼3 times greater than that of the bare copper, indicating graphene coatings could improve the corrosion resistance of copper bipolar plates.

High temperature corrosion of metallic interconnects in solid oxide fuel cells

International Nuclear Information System (INIS)

Bastidas, D. M.

2006-01-01

Research and development has made it possible to use metallic interconnects in solid oxide fuel cells (SOFC) instead of ceramic materials. The use of metallic interconnects was formerly hindered by the high operating temperature, which made the interconnect degrade too much and too fast to be an efficient alternative. When the operating temperature was lowered, the use of metallic interconnects proved to be favourable since they are easier and cheaper to produce than ceramic interconnects. However, metallic interconnects continue to be degraded despite the lowered temperature, and their corrosion products contribute to electrical degradation in the fuel cell. coatings of nickel, chromium, aluminium, zinc, manganese, yttrium or lanthanum between the interconnect and the electrodes reduce this degradation during operation. (Author) 66 refs

Proton exchange membrane fuel cell operation and degradation in short-circuit.

OpenAIRE

Silva , R.E.; Harel , F.; Jemei , S.; Gouriveau , Rafael; Hissel , Daniel; Boulon , L.; Agbossou , K.

2013-01-01

International audience; Hybridization of proton exchange membrane fuel cells (PEMFC) and ultra capacitors (UC) are considered as an alternative way to implement high autonomy, high dynamic, and reversible energy sources. PEMFC allow high efficiency and high autonomy, however their dynamic response is limited and this source does not allow recovering energy. UC appears to be a complementary source to fuel cell systems (FCS) due to their high power density, fast dynamics, and reversibility. A d...

Fuel Cell Balance-of-Plant Reliability Testbed Project

Energy Technology Data Exchange (ETDEWEB)

Sproat, Vern [Stark State College of Technology, North Canton, OH (United States); LaHurd, Debbie [Lockheed Martin Corp., Oak Ridge, TN (United States)

2016-10-29

Reliability of the fuel cell system balance-of-plant (BoP) components is a critical factor that needs to be addressed prior to fuel cells becoming fully commercialized. Failure or performance degradation of BoP components has been identified as a life-limiting factor in fuel cell systems.1 The goal of this project is to develop a series of test beds that will test system components such as pumps, valves, sensors, fittings, etc., under operating conditions anticipated in real Polymer Electrolyte Membrane (PEM) fuel cell systems. Results will be made generally available to begin removing reliability as a roadblock to the growth of the PEM fuel cell industry. Stark State College students participating in the project, in conjunction with their coursework, have been exposed to technical knowledge and training in the handling and maintenance of hydrogen, fuel cells and system components as well as component failure modes and mechanisms. Three test beds were constructed. Testing was completed on gas flow pumps, tubing, and pressure and temperature sensors and valves.

Thermal modeling and temperature control of a PEM fuel cell system for forklift applications

DEFF Research Database (Denmark)

Liso, Vincenzo; Nielsen, Mads Pagh; Kær, Søren Knudsen

2014-01-01

Temperature changes in PEM fuel cell stacks are considerably higher during load variations and have a negative impact as they generate thermal stresses and stack degradation. Cell hydration is also of vital importance in fuel cells and it is strongly dependent on operating temperature....... A combination of high temperature and reduced humidity increases the degradation rate. Stack thermal management and control are, thus, crucial issues in PEM fuel cell systems especially in automotive applications such as forklifts. In this paper we present a control–oriented dynamic model of a liquid–cooled PEM...... fuel cell system for studying temperature variations over fast load changes. A temperature dependent cell polarization and hydration model integrated with the compressor, humidifier and cooling system are simulated in dynamic condition. A feedback PID control was implemented for stack cooling...

Alternate Fuel Cell Membranes for Energy Independence

Energy Technology Data Exchange (ETDEWEB)

Storey, Robson, F.; Mauritz, Kenneth, A.; Patton, Derek, L.; Savin, Daniel, A.

2012-12-18

performance properties of experimental membranes, 9) fabrication and FC performance testing of membrane electrode assemblies (MEA) from experimental membranes, and 10) measurement of ex situ and in situ membrane durability of experimental membranes. Although none of the experimental hydrocarbon membranes that issued from the project displayed proton conductivities that met DOE requirements, the project contributed to our basic understanding of membrane structure-property relationships in a number of key respects. An important finding of the benchmark studies is that physical degradation associated with humidity and temperature variations in the FC tend to open new fuel crossover pathways and act synergistically with chemical degradation to accelerate overall membrane degradation. Thus, for long term membrane survival and efficient fuel utilization, membranes must withstand internal stresses due to humidity and temperature changes. In this respect, rigid aromatic hydrocarbon fuel cell membranes, e.g. PAES, offer an advantage over un-modified Nafion membranes. The benchmark studies also showed that broadband dielectric spectroscopy is a potentially powerful tool in assessing shifts in the fundamental macromolecular dynamics caused by Nafion chemical degradation, and thus, this technique is of relevance in interrogating proton exchange membrane durability in fuel cells and macromolecular dynamics as coupled to proton migration, which is of fundamental relevance in proton exchange membranes in fuel cells. A key finding from the hydrocarbon membrane synthesis effort was that rigid aromatic polymers containing isolated ion exchange groups tethered tightly to the backbone (short tether), such as HPPS, provide excellent mechanical and durability properties but do not provide sufficient conductivity, in either random or block configuration, when used as the sole ion exchange monomer. However, we continue to hypothesize that longer tethers, and tethered groups spaced more closely

Hydrogen fuel injection - the bridge to fuel cells

International Nuclear Information System (INIS)

Gilchrist, J.S.

2004-01-01

'Full text:' For over a century, industry has embraced a wide variety of applications for hydrogen. Since the mid-1970's, the focus of the bulk of hydrogen research has been in the area of fuel cells. Unfortunately, there is limited awareness of more immediate applications for hydrogen as a catalyst designed to improve the performance of existing hydro-carbon fuelled internal combustion engines. Canadian Hydrogen Energy Company manufactures a patented Hydrogen Fuel Injection System (HFI) that produces hydrogen and oxygen from distilled water and injects them, in measured amounts, into the air intake system on any heavy-duty diesel or gasoline application including trucks, buses, stationary generators, etc. In use on over 30 fleets, research is supported by over 40 million miles of field data. The hydrogen acts as a catalyst to promote more complete combustion, with remarkable results. Dramatically reduce emissions, particularly Carbon Monoxide and Particulate Matter. Increase horsepower and torque. Improved fuel efficiency (a minimum 10% improvement is guaranteed). Reduced oil degradation The HFI system offers the first large-scale application of the use of hydrogen and an excellent bridge to the fuel-cell technologies of the future. (author)

High temperature PEM fuel cells

Energy Technology Data Exchange (ETDEWEB)

Zhang, Jianlu; Xie, Zhong; Zhang, Jiujun; Tang, Yanghua; Song, Chaojie; Navessin, Titichai; Shi, Zhiqing; Song, Datong; Wang, Haijiang; Wilkinson, David P.; Liu, Zhong-Sheng; Holdcroft, Steven [Institute for Fuel Cell Innovation, National Research Council Canada, Vancouver, BC (Canada V6T 1W5)

2006-10-06

There are several compelling technological and commercial reasons for operating H{sub 2}/air PEM fuel cells at temperatures above 100{sup o}C. Rates of electrochemical kinetics are enhanced, water management and cooling is simplified, useful waste heat can be recovered, and lower quality reformed hydrogen may be used as the fuel. This review paper provides a concise review of high temperature PEM fuel cells (HT-PEMFCs) from the perspective of HT-specific materials, designs, and testing/diagnostics. The review describes the motivation for HT-PEMFC development, the technology gaps, and recent advances. HT-membrane development accounts for {approx}90% of the published research in the field of HT-PEMFCs. Despite this, the status of membrane development for high temperature/low humidity operation is less than satisfactory. A weakness in the development of HT-PEMFC technology is the deficiency in HT-specific fuel cell architectures, test station designs, and testing protocols, and an understanding of the underlying fundamental principles behind these areas. The development of HT-specific PEMFC designs is of key importance that may help mitigate issues of membrane dehydration and MEA degradation. (author)

Summary report on the aerobic degradation of diesel fuel and the degradation of toluene under aerobic, denitrifying and sulfate reducing conditions

International Nuclear Information System (INIS)

Coyne, P.; Smith, G.

1995-01-01

This report contains a number of studies that were performed to better understand the technology of the biodegradation of petroleum hydrocarbons. Topics of investigation include the following: diesel fuel degradation by Rhodococcus erythropolis; BTEX degradation by soil isolates; aerobic degradation of diesel fuel-respirometry; aerobic degradation of diesel fuel-shake culture; aerobic toluene degradation by A3; effect of HEPES, B1, and myo-inositol addition on the growth of A3; aerobic and anaerobic toluene degradation by contaminated soils; denitrifying bacteria MPNs; sulfate-reducing bacteria MPNs; and aerobic, DNB and SRB enrichments

Degradation resistant fuel cladding materials and manufacturing

Energy Technology Data Exchange (ETDEWEB)

Marlowe, M.O. [GE Nuclear Energy, Wilmington, NC (United States); Montes, J. [ENUSA, Madrid (Spain)

1995-12-31

GE has been producing the degradation resistant cladding (zirconium liner and zircaloy-2 surface larger) described here with the cooperation of its primary zirconium vendors since the beginning of 1994. Approximately 24 fuel reloads, or in excess of 250,000 fuel rods, have been produced using this material by GE. GE has also produced tubing for one reload of fuel that is currently being produced by its technology affiliate ENUSA. (orig./HP)

Fuel cell generator with fuel electrodes that control on-cell fuel reformation

Science.gov (United States)

Ruka, Roswell J [Pittsburgh, PA; Basel, Richard A [Pittsburgh, PA; Zhang, Gong [Murrysville, PA

2011-10-25

A fuel cell for a fuel cell generator including a housing including a gas flow path for receiving a fuel from a fuel source and directing the fuel across the fuel cell. The fuel cell includes an elongate member including opposing first and second ends and defining an interior cathode portion and an exterior anode portion. The interior cathode portion includes an electrode in contact with an oxidant flow path. The exterior anode portion includes an electrode in contact with the fuel in the gas flow path. The anode portion includes a catalyst material for effecting fuel reformation along the fuel cell between the opposing ends. A fuel reformation control layer is applied over the catalyst material for reducing a rate of fuel reformation on the fuel cell. The control layer effects a variable reformation rate along the length of the fuel cell.

Identical location transmission electron microscopy in combination with rotating disc electrode measurements. The activity of fuel cell catalysts and their degradation

Energy Technology Data Exchange (ETDEWEB)

Schloegl, Katrin G.

2011-07-13

As an alternative to conventional combustion engines, the Proton Exchange Membrane Fuel Cell (PEMFC) using hydrogen as a fuel is a promising concept owing to its potential independence from fossil fuels, high efficiency and zero emissions. Concerning its commercial viability, the fundamental problem of high system cost per power output and lifetime is closely related to finding more active and stable catalysts for the oxygen reduction reaction. In the presented work, several methods are combined to examine the parameters and processes responsible for both activity and degradation of platinum-based catalysts. Degradation mechanisms are scrutinized by means of electrochemical measurements with the rotating disc electrode in combination with a recently developed TEM technique, which allows for the comparison of identical locations before and after accelerated stress tests. (orig.) [German] Die mit Wasserstoff betriebene Proton Exchange Membrane Brennstoffzelle (PEMFC) stellt aufgrund ihrer potentiellen Unabhaengigkeit von fossilen Energietraegern, ihrem hohen Wirkungsgrad und fehlendem Schadstoffausstoss eine vielversprechende Alternative zum konventionellen Verbrennungsmotor dar. Das grundlegende Problem der zu hohen Systemkosten und zu geringen Lebensdauer fuer kommerzielle Anwendungen ist eng mit der Entwicklung aktiverer und stabiler Elektrokatalysatoren fuer die Sauerstoffreduktion verknuepft. In der vorliegenden Arbeit werden verschiedene Methoden kombiniert, um die Parameter und Prozesse zu untersuchen, welche fuer die Aktivitaet und Degradation platinbasierter Katalysatoren verantwortlich sind. Zur Aufklaerung vorliegender Degradationsmechanismen werden elektrochemische Messungen mit der rotierenden Scheibenelektrode in Kombination mit einer neu entwickelten TEM Methode eingesetzt, welche es ermoeglicht, identische Stellen vor und nach beschleunigten Degradationstests zu untersuchen.

Pt/C Fuel Cell Catalyst Degradation

DEFF Research Database (Denmark)

Zana, Alessandro

This thesis investigates the degradation behavior of Pt/C catalysts under simulated automotive conditions. By using the “tool box” synthesis method the Pt loading has been changed from low to high Pt loadings, therefore permitting to study the role of Pt on the degradation of high surface area (H...

Solid oxide fuel cell performance under severe operating conditions

DEFF Research Database (Denmark)

Koch, Søren; Hendriksen, P.V.; Mogensen, Mogens Bjerg

2006-01-01

The performance and degradation of Solid Oxide Fuel Cells (SOFC) were studied under severe operating conditions. The cells studied were manufactured in a small series by ECN, in the framework of the EU funded CORE-SOFC project. The cells were of the anode-supported type with a double layer LSM...... cathode. They were operated at 750 °C or 850 °C in hydrogen with 5% or 50% water at current densities ranging from 0.25 A cm–2 to 1 A cm–2 for periods of 300 hours or more. The area specific cell resistance, corrected for fuel utilisation, ranged between 0.20 Ω cm2 and 0.34 Ω cm2 at 850 °C and 520 m......V, and between 0.51 Ω cm2 and 0.92 Ω cm2 at 750 °C and 520 mV. The degradation of cell performance was found to be low (ranging from 0 to 8%/1,000 hours) at regular operating conditions. Voltage degradation rates of 20 to 40%/1,000 hours were observed under severe operating conditions, depending on the test...

Fuel Exhaling Fuel Cell.

Science.gov (United States)

Manzoor Bhat, Zahid; Thimmappa, Ravikumar; Devendrachari, Mruthyunjayachari Chattanahalli; Kottaichamy, Alagar Raja; Shafi, Shahid Pottachola; Varhade, Swapnil; Gautam, Manu; Thotiyl, Musthafa Ottakam

2018-01-18

State-of-the-art proton exchange membrane fuel cells (PEMFCs) anodically inhale H 2 fuel and cathodically expel water molecules. We show an unprecedented fuel cell concept exhibiting cathodic fuel exhalation capability of anodically inhaled fuel, driven by the neutralization energy on decoupling the direct acid-base chemistry. The fuel exhaling fuel cell delivered a peak power density of 70 mW/cm 2 at a peak current density of 160 mA/cm 2 with a cathodic H 2 output of ∼80 mL in 1 h. We illustrate that the energy benefits from the same fuel stream can at least be doubled by directing it through proposed neutralization electrochemical cell prior to PEMFC in a tandem configuration.

Durability Improvements Through Degradation Mechanism Studies

Energy Technology Data Exchange (ETDEWEB)

Borup, Rodney L. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Mukundan, Rangachary [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Spernjak, Dusan [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Baker, Andrew M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Lujan, Roger W. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Langlois, David Alan [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Ahluwalia, Rajesh [Argonne National Lab. (ANL), Argonne, IL (United States); Papadia, D. D. [Argonne National Lab. (ANL), Argonne, IL (United States); Weber, Adam Z. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Kusoglu, Ahmet [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Shi, Shouwnen [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); More, K. L. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Grot, Steve [Ion Power, New Castle, DE (United States)

2015-08-03

The durability of polymer electrolyte membrane (PEM) fuel cells is a major barrier to the commercialization of these systems for stationary and transportation power applications. By investigating cell component degradation modes and defining the fundamental degradation mechanisms of components and component interactions, new materials can be designed to improve durability. To achieve a deeper understanding of PEM fuel cell durability and component degradation mechanisms, we utilize a multi-institutional and multi-disciplinary team with significant experience investigating these phenomena.

Final Report - MEA and Stack Durability for PEM Fuel Cells

Energy Technology Data Exchange (ETDEWEB)

Yandrasits, Michael A.

2008-02-15

Proton exchange membrane fuel cells are expected to change the landscape of power generation over the next ten years. For this to be realized one of the most significant challenges to be met for stationary systems is lifetime, where 40,000 hours of operation with less than 10% decay is desired. This project conducted fundamental studies on the durability of membrane electrode assemblies (MEAs) and fuel cell stack systems with the expectation that knowledge gained from this project will be applied toward the design and manufacture of MEAs and stack systems to meet DOE’s 2010 stationary fuel cell stack systems targets. The focus of this project was PEM fuel cell durability – understanding the issues that limit MEA and fuel cell system lifetime, developing mitigation strategies to address the lifetime issues and demonstration of the effectiveness of the mitigation strategies by system testing. To that end, several discoveries were made that contributed to the fundamental understanding of MEA degradation mechanisms. (1) The classically held belief that membrane degradation is solely due to end-group “unzipping” is incorrect; there are other functional groups present in the ionomer that are susceptible to chemical attack. (2) The rate of membrane degradation can be greatly slowed or possibly eliminated through the use of additives that scavenge peroxide or peroxyl radicals. (3) Characterization of GDL using dry gases is incorrect due to the fact that fuel cells operate utilizing humidified gases. The proper characterization method involves using wet gas streams and measuring capillary pressure as demonstrated in this project. (4) Not all Platinum on carbon catalysts are created equally – the major factor impacting catalyst durability is the type of carbon used as the support. (5) System operating conditions have a significant impact of lifetime – the lifetime was increased by an order of magnitude by changing the load profile while all other variables remain

Determination of membrane degradation products in the product water of polymer electrolyte membrane fuel cells using liquid chromatography mass spectrometry

Energy Technology Data Exchange (ETDEWEB)

Zedda, Marco

2011-05-12

The predominant long term failure of polymer electrolyte membranes (PEM) is caused by hydroxyl radicals generated during fuel cell operation. These radicals attack the polymer, leading to chain scission, unzipping and consequently to membrane decomposition products. The present work has investigated decomposition products of novel sulfonated aromatic hydrocarbon membranes on the basis of a product water analysis. Degradation products from the investigated membrane type and the possibility to detect these compounds in the product water for diagnostic purposes have not been discovered yet. This thesis demonstrates the potential of solid phase extraction and liquid chromatography tandem mass spectrometry (SPE-LC-MS/MS) for the extraction, separation, characterization, identification and quantification of membrane degradation products in the product water of fuel cells. For this purpose, several polar aromatic hydrocarbons with different functional groups were selected as model compounds for the development of reliable extraction, separation and detection methods. The results of this thesis have shown that mixed mode sorbent materials with both weak anion exchange and reversed phase retention properties are well suited for reproducible extraction of both molecules and ions from the product water. The chromatographic separation of various polar aromatic hydrocarbons was achieved by means of phase optimized liquid chromatography using a solvent gradient and on a C18 stationary phase. Sensitive and selective detection of model compounds could be successfully demonstrated by the analysis of the product water using tandem mass spectrometry. The application of a hybrid mass spectrometer (Q Trap) for the characterization of unknown polar aromatic hydrocarbons has led to the identification and confirmation of 4-hydroxybenzoic acid in the product water. In addition, 4-HBA could be verified as a degradation product resulting from PEM decomposition by hydroxyl radicals using an

Optimization of degradation of Reactive Black 5 (RB5) and electricity generation in solar photocatalytic fuel cell system.

Science.gov (United States)

Khalik, Wan Fadhilah; Ho, Li-Ngee; Ong, Soon-An; Voon, Chun-Hong; Wong, Yee-Shian; Yusoff, NikAthirah; Lee, Sin-Li; Yusuf, Sara Yasina

2017-10-01

The photocatalytic fuel cell (PFC) system was developed in order to study the effect of several operating parameters in degradation of Reactive Black 5 (RB5) and its electricity generation. Light irradiation, initial dye concentration, aeration, pH and cathode electrode are the operating parameters that might give contribution in the efficiency of PFC system. The degradation of RB5 depends on the presence of light irradiation and solar light gives better performance to degrade the azo dye. The azo dye with low initial concentration decolorizes faster compared to higher initial concentration and presence of aeration in PFC system would enhance its performance. Reactive Black 5 rapidly decreased at higher pH due to the higher amount of OH generated at higher pH and Pt-loaded carbon (Pt/C) was more suitable to be used as cathode in PFC system compared to Cu foil and Fe foil. The rapid decolorization of RB5 would increase their voltage output and in addition, it would also increase their V oc , J sc and P max . The breakage of azo bond and aromatic rings was confirmed through UV-Vis spectrum and COD analysis. Copyright © 2017 Elsevier Ltd. All rights reserved.

Optimised control between fuel cell and battery in 'zero emission' fuel cell drives; Optimierung der Regelung zwischen Brennstoffzelle und Batterie in 'Zero-Emission' Brennstoffzellen-Antrieben

Energy Technology Data Exchange (ETDEWEB)

Herb, F.; Jossen, A. [Zentrum fuer Sonnenenergie- und Wasserstoff-Forschung (ZSW), Ulm (Germany); Frank, A. [Univ. Ulm (Germany); Nitsche, C. [Mercedes-Benz Technology GmbH, Sindelfingen (Germany)

2008-07-01

The contribution investigates the effects of various hybridisation strategies for fuel cell hybrid vehicles on the life of the fuel cell and the high-voltage battery and on hydrogen consumption on the basis of different driving cycles. The hybridisation strategies focus on the control of the power distribution of the fuel cell and battery. The investigation was carried out using a specially vehicle simulation model and vehicle data of the Advisor model. Quality parametersdefined for the life of the fuel cell and battery are presented in a diagram. Further, the influence of a degraded fuel cell on the control efficiency was investigated. For this, a fuel cell model was established on the basis of artificial neuronal networks based on real driving data, which was integrated in the vehicle model. The changes are discussed on the basis of the dependence of the quality parameters on the various control parameters. (orig.)

Fuel Cell and Hydrogen Technology Validation | Hydrogen and Fuel Cells |

Science.gov (United States)

NREL Fuel Cell and Hydrogen Technology Validation Fuel Cell and Hydrogen Technology Validation The NREL technology validation team works on validating hydrogen fuel cell electric vehicles; hydrogen fueling infrastructure; hydrogen system components; and fuel cell use in early market applications such as

Anode Supported Solid Oxide Fuel Cells - Deconvolution of Degradation into Cathode and Anode Contributions

DEFF Research Database (Denmark)

Hagen, Anke; Liu, Yi-Lin; Barfod, Rasmus

2007-01-01

The degradation of anode supported cells was studied over 1500 h as function of cell polarization either in air or oxygen on the cathode. Based on impedance analysis, contributions of anode and cathode to the increase of total resistance were assigned. Accordingly, the degradation rates...... of the cathode were strongly dependent on the pO(2); they were significantly smaller when testing in oxygen compared to air. Microstructural analysis of the cathode/electrolyte interface of a not-tested reference cell carried out after removal of the cathode showed sharp craters on the electrolyte surface where...

Operation strategy for solid oxide fuel cell systems for small-scale stationary applications

DEFF Research Database (Denmark)

Liso, Vincenzo; Nielsen, Mads Pagh; Kær, Søren Knudsen

2009-01-01

Solid oxide fuel cell micro cogeneration systems have the potential to reduce domestic energy consumption by providing both heat and power on site without transmission losses. The high grade heat produced during the operation of the power causes high thermal transients during startup/shutdown pha......Solid oxide fuel cell micro cogeneration systems have the potential to reduce domestic energy consumption by providing both heat and power on site without transmission losses. The high grade heat produced during the operation of the power causes high thermal transients during startup....../shutdown phases and degrades the fuel cells. To counteract the degradation, the system has not to be stressed with rapid load variation during the operation. The analysis will consider an average profile for heat and power demand of a family house. Finally data analysis and power system limitations will be used...

Optimised fuel cell operation management. Final report; Optimiertes Betriebsmanagement von Brennstoffzellen. Schlussbericht

Energy Technology Data Exchange (ETDEWEB)

NONE

2003-11-05

Investigations were carried out on two fuel cell systems of the type ONSI PC 25C (large fuel cells) and three fuel cell heaters of the type HXS 1000 PREMIERE by Sulzer HEXIS (small fuel cells) for long periods of time and in different modes of operation. Information was obtained on efficiencies and performance, pollutant emissions, degradation and availability. The status of the project is reported and compared with the goals stated initially. (orig.) [German] Das Hauptziel des Projektes bestand darin, Kriterien fuer den optimalen Betrieb (hohe Verfuegbarkeit, geringe Anzahl von Abschaltungen, hohe Energienutzung etc.) von Brennstoffzellen im Zusammenspiel mit den peripheren Komponenten der Gebaeudetechnik zu ermitteln. Hierzu wurden Untersuchungen an zwei Brennstoffzellen-Anlagen vom Typ ONSI PC 25C (grosse BZ) und an drei Brennstoffzellen-Heizgeraeten HXS 1000 PREMIERE von Sulzer HEXIS (kleine BZ) ueber laengere Zeitraeume und bei weitestgehend unterschiedlichen Betriebsweisen durchgefuehrt. In Auswertung dieser Messkomplexe wurden Aussagen zum Betriebsverhalten der Brennstoffzellen, wie z.B. zu Wirk- und Nutzungsgraden, Schadstoffemissionen, Verlauf der Degradation sowie zur Verfuegbarkeit getroffen. Im vorliegenden Bericht wird der erreichte Sachstand detailliert dargestellt und mit den Zielsetzungen des FuE-Antrages verglichen. (orig.)

Solid oxide fuel cell performance comparison fueled by methane, MeOH, EtOH and gasoline surrogate C_8H_1_8

International Nuclear Information System (INIS)

Liso, Vincenzo; Cinti, Giovanni; Nielsen, Mads P.; Desideri, Umberto

2016-01-01

Carbon deposition is a major cause of degradation in solid oxide fuel cell systems. The ability to predict carbon formation in reforming processes is thus absolutely necessary for stable operation of solid oxide fuel cell systems. In the open literature it is found that the steam input is always considered in large excess compared to what required by the reforming process with the purpose of reducing carbon formation and avoiding rapid degradation of the cell performance. This makes it difficult to consistently compare system performance with different fuels. In this work, the molar compositions at equilibrium are calculated for a minimum steam to carbon ratio for each fuel type. We carry out a thermodynamic analysis of fuel/steam system using Gibbs Free Energy minimization method. A mathematical relationship between Lagrange's multipliers and carbon activity in the gas phase was deduced. Minimum steam required for the reforming process for each fuel was related to the heat required for the reforming process and fuel cell open circuit voltage. Furthermore, in an experimental test, steam reforming product compositions were used to evaluate and compare SOFC performance with different hydrocarbons. Comparing the model to the experimental activity, it is revealed that at temperatures exceeding 800 °C the gas composition is dominated by hydrogen and carbon monoxide for any of the fuels considered leading to similar cell polarization curves performance for different fuels. The main effect on the performance is related to OCV values which are dependent on different steam content for each fuel. It was concluded that the magnitude of the heat requested for the fuel reforming process is the major difference in system performance when comparing different fuels. However, reforming kinetic effects can become predominant rather than thermodynamics, especially at lower temperatures.

Durability Issues and Status of PBI-Based Fuel Cells

DEFF Research Database (Denmark)

Jakobsen, Mark Tonny Dalsgaard; Jensen, Jens Oluf; Cleemann, Lars Nilausen

2016-01-01

This chapter briefly reviews durability and stability issues with key materials and components for HT-PEMFCs, including the polymer membrane, the doping acid, the electrocatalyst, the catalyst support and bipolar plates. Degradation mechanisms and their dependence on fuel cell operating condition...

Operation of real landfill gas fueled solid oxide fuel cell (SOFC) using internal dry reforming

DEFF Research Database (Denmark)

Langnickel, Hendrik; Hagen, Anke

2017-01-01

Biomass is one renewable energy source, which is independent from solar radiation and wind effect. Solid oxide fuel cells (SOFC’s) are able to convert landfill gas derived from landfill directly into electricity and heat with a high efficiency. In the present work a planar 16cm2 SOFC cell...... was necessary to prevent poisoning and thereby to decrease the degradation rate....

Microbial surface displayed enzymes based biofuel cell utilizing degradation products of lignocellulosic biomass for direct electrical energy.

Science.gov (United States)

Fan, Shuqin; Hou, Chuantao; Liang, Bo; Feng, Ruirui; Liu, Aihua

2015-09-01

In this work, a bacterial surface displaying enzyme based two-compartment biofuel cell for the direct electrical energy conversion from degradation products of lignocellulosic biomass is reported. Considering that the main degradation products of the lignocellulose are glucose and xylose, xylose dehydrogenase (XDH) displayed bacteria (XDH-bacteria) and glucose dehydrogenase (GDH) displayed bacteria (GDH-bacteria) were used as anode catalysts in anode chamber with methylene blue as electron transfer mediator. While the cathode chamber was constructed with laccase/multi-walled-carbon nanotube/glassy-carbon-electrode. XDH-bacteria exhibited 1.75 times higher catalytic efficiency than GDH-bacteria. This assembled enzymatic fuel cell exhibited a high open-circuit potential of 0.80 V, acceptable stability and energy conversion efficiency. Moreover, the maximum power density of the cell could reach 53 μW cm(-2) when fueled with degradation products of corn stalk. Thus, this finding holds great potential to directly convert degradation products of biomass into electrical energy. Copyright © 2015 Elsevier Ltd. All rights reserved.

Development of PEM fuel cell technology at international fuel cells

Energy Technology Data Exchange (ETDEWEB)

Wheeler, D.J.

1996-04-01

The PEM technology has not developed to the level of phosphoric acid fuel cells. Several factors have held the technology development back such as high membrane cost, sensitivity of PEM fuel cells to low level of carbon monoxide impurities, the requirement to maintain full humidification of the cell, and the need to pressurize the fuel cell in order to achieve the performance targets. International Fuel Cells has identified a hydrogen fueled PEM fuel cell concept that leverages recent research advances to overcome major economic and technical obstacles.

Fuel Cell and Hydrogen Technologies Program | Hydrogen and Fuel Cells |

Science.gov (United States)

NREL Fuel Cell and Hydrogen Technologies Program Fuel Cell and Hydrogen Technologies Program Through its Fuel Cell and Hydrogen Technologies Program, NREL researches, develops, analyzes, and validates fuel cell and hydrogen production, delivery, and storage technologies for transportation

Thermal conductivity degradation analyses of LWR MOX fuel by the quasi-two phase material model

International Nuclear Information System (INIS)

Kosaka, Yuji; Kurematsu, Shigeru; Kitagawa, Takaaki; Suzuki, Akihiro; Terai, Takayuki

2012-01-01

The temperature measurements of mixed oxide (MOX) and UO 2 fuels during irradiation suggested that the thermal conductivity degradation rate of the MOX fuel with burnup should be slower than that of the UO 2 fuel. In order to explain the difference of the degradation rates, the quasi-two phase material model is proposed to assess the thermal conductivity degradation of the MIMAS MOX fuel, which takes into account the Pu agglomerate distributions in the MOX fuel matrix as fabricated. As a result, the quasi-two phase model calculation shows the gradual increase of the difference with burnup and may expect more than 10% higher thermal conductivity values around 75 GWd/t. While these results are not fully suitable for thermal conductivity degradation models implemented by some industrial fuel manufacturers, they are consistent with the results from the irradiation tests and indicate that the inhomogeneity of Pu content in the MOX fuel can be one of the major reasons for the moderation of the thermal conductivity degradation of the MOX fuel. (author)

Non-destructive delamination detection in solid oxide fuel cells

Energy Technology Data Exchange (ETDEWEB)

Gazzarri, J.I.; Kesler, O. [Department of Mechanical Engineering, University of British Columbia, 2054-6250 Applied Science Lane, Vancouver, BC V6T 1Z4 (Canada)

2007-05-15

A finite element model has been developed to simulate the steady state and impedance behaviour of a single operating solid oxide fuel cell (SOFC). The model results suggest that electrode delamination can be detected minimally-invasively by using electrochemical impedance spectroscopy. The presence of cathode delamination causes changes in the cell impedance spectrum that are characteristic of this type of degradation mechanism. These changes include the simultaneous increase in both the series and polarization resistances, in proportion to the delaminated area. Parametric studies show the dependence of these changes on the extent of delamination, on the operating point, and on the kinetic characteristics of the fuel cell under study. (author)

Hydroxide Self-Feeding High-Temperature Alkaline Direct Formate Fuel Cells.

Science.gov (United States)

Li, Yinshi; Sun, Xianda; Feng, Ying

2017-05-22

Conventionally, both the thermal degradation of the anion-exchange membrane and the requirement of additional hydroxide for fuel oxidation reaction hinder the development of the high-temperature alkaline direct liquid fuel cells. The present work addresses these two issues by reporting a polybenzimidazole-membrane-based direct formate fuel cell (DFFC). Theoretically, the cell voltage of the high-temperature alkaline DFFC can be as high as 1.45 V at 90 °C. It has been demonstrated that a proof-of-concept alkaline DFFC without adding additional hydroxide yields a peak power density of 20.9 mW cm -2 , an order of magnitude higher than both alkaline direct ethanol fuel cells and alkaline direct methanol fuel cells, mainly because the hydrolysis of formate provides enough OH - ions for formate oxidation reaction. It was also found that this hydroxide self-feeding high-temperature alkaline DFFC shows a stable 100 min constant-current discharge at 90 °C, proving the conceptual feasibility. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Fuel Cell Electric Bus Evaluations | Hydrogen and Fuel Cells | NREL

Science.gov (United States)

Bus Evaluations Fuel Cell Electric Bus Evaluations NREL's technology validation team evaluates fuel cell electric buses (FCEBs) to provide comprehensive, unbiased evaluation results of fuel cell bus early transportation applications for fuel cell technology. Buses operate in congested areas where

Fuel Cell Manufacturing Research and Development | Hydrogen and Fuel Cells

Science.gov (United States)

| NREL Fuel Cell Manufacturing Research and Development Fuel Cell Manufacturing Research and Development NREL's fuel cell manufacturing R&D focuses on improving quality-inspection practices for high costs. A researcher monitoring web-line equipment in the Manufacturing Laboratory Many fuel cell

Survey on aging on electrodes and electrocatalysts in phosphoric acid fuel cells

Science.gov (United States)

Stonehart, P.; Hochmuth, J.

1981-01-01

The processes which contribute to the decay in performance of electrodes used in phosphoric acid fuel cell systems are discussed. Loss of catalytic surface area, corrosion of the carbon support, electrode structure degradation, electrolyte degradation, and impurities in the reactant streams are identified as the major areas for concern.

Degradation of nitrile rubber fuel hose by biodiesel use

International Nuclear Information System (INIS)

Coronado, Marcos; Montero, Gisela; Valdez, Benjamín; Stoytcheva, Margarita; Eliezer, Amir; García, Conrado; Campbell, Héctor; Pérez, Armando

2014-01-01

Nowadays biodiesel is becoming an increasingly important and popular fuel, obtained from renewable sources, and contributes to pollutant emissions reduction and decreasing fossil fuels dependence. However, its easier oxidation and faster degradation in comparison to diesel led to compatibility problems between biodiesel and various metallic and polymeric materials contacted. Therefore, the objective of this work is to investigate the effect of different mixtures diesel–biodiesel (fuel type B5, B10, B20) used in Baja California, Mexico on the resistance of nitrile rubber fuel hoses at temperatures of 25 °C and 70 °C applying gravimetric tests, tensile strength measurements and scanning electron microscopy analysis. The factors affecting the material mass change were identified using an experimental design analysis. It was found that the fuel temperature did not conduct to significant mass loss of nitrile rubber fuel hose, while biodiesel concentration affected the properties of the elastomer, causing the phenomenon of swelling. The exposure of hoses to fuel with increasing concentrations of biodiesel led to tensile strength decrease. - Highlights: • The biodiesel oxidation led to problems with polymeric materials. • The degradation of a nitrile rubber fuel hose in biodiesel blends was assessed. • The nitrile rubber showed greater affinity for biodiesel than diesel. • The elastomer swelled, cracked and lost its mechanical properties by biodiesel. • SEM analysis confirmed surface morphology changes in higher biodiesel blends

Fuel Cell Technology Status Analysis | Hydrogen and Fuel Cells | NREL

Science.gov (United States)

Technology Status Analysis Fuel Cell Technology Status Analysis Get Involved Fuel cell developers interested in collaborating with NREL on fuel cell technology status analysis should send an email to NREL's Technology Validation Team at techval@nrel.gov. NREL's analysis of fuel cell technology provides objective

Investigation of Ruthenium Dissolution in Advanced Membrane Electrode Assemblies for Direct Methanol Based Fuel Cells Stacks

Science.gov (United States)

Valdez, T. I.; Firdosy, S.; Koel, B. E.; Narayanan, S. R.

2005-01-01

This viewgraph presentation gives a detailed review of the Direct Methanol Based Fuel Cell (DMFC) stack and investigates the Ruthenium that was found at the exit of the stack. The topics include: 1) Motivation; 2) Pathways for Cell Degradation; 3) Cell Duration Testing; 4) Duration Testing, MEA Analysis; and 5) Stack Degradation Analysis.

Electroplating of Protective Coatings on Interconnects Used for Solid Oxide Fuel Cell Stacks

DEFF Research Database (Denmark)

Harthøj, Anders

Solid oxide fuel Cell (SOFC) technology can with a high efficiency produce environmentally clean electricity by converting the chemical energy in a fuel to electrical energy. SOFC systems have a high operation temperature, approx. 600-850 °C. Advantages compared to other types of fuel cells......, are they can utilize a wide range of fuels, e.g. hydrogen, natural gas and methanol, do not contain noble metals and have a high efficiency. A major obstacle to the commercialization of SOFC technology is the high degradation rates and costs of the systems. A significant source of degradation is high...... on the side facing its anode. Two high temperature corrosion issues, which both affect the air side of the interconnect, are especially significant, both of: Formation of thick oxide scales on its surface and evaporation of chromium species from the oxide. The oxide scales increases the electrical resistance...

Fuel cells 101

Energy Technology Data Exchange (ETDEWEB)

Taylor, B.

2003-06-01

A capsule history of fuel cells is given, beginning with the first discovery in 1839 by William Grove, a Welsh judge who, when experimenting with electrolysis discovered that by re-combining the two components of electrolysis (water and oxygen) an electric charge was produced. A century later, in 1958, Francis Thomas Bacon, a British scientist demonstrated the first working fuel cell stack, a technology which was licensed and used in the Apollo spacecraft. In Canada, early research on the development of fuel cells was carried out at the University of Toronto, the Defence Research Establishment and the National Research Council. Most of the early work concentrated on alkaline and phosphoric acid fuel cells. In 1983, Ballard Research began the development of the electrolyte membrane fuel cell, which marked the beginning of Canada becoming a world leader in fuel cell technology development. The paper provides a brief account of how fuel cells work, describes the distinguishing characteristics of the various types of fuel cells (alkaline, phosphoric acid, molten-carbonate, solid oxide, and proton exchange membrane types) and their principal benefits. The emphasis is on proton exchange membrane fuel cells because they are the only fuel cell technology that is appropriate for providing primary propulsion power onboard a vehicle. Since vehicles are by far the greatest consumers of fossil fuels, it follows that proton exchange membrane fuel cells will have the greatest potential impact on both environmental matters and on our reliance on oil as our primary fuel. Various on-going and planned fuel cell demonstration projects are also described. 1 fig.

Spectroelectrochemical cell for in situ studies of solid oxide fuel cells

DEFF Research Database (Denmark)

Hagen, Anke; Traulsen, Marie Lund; Kiebach, Wolff-Ragnar

2012-01-01

to control before the technology can achieve breakthrough. They have been widely studied, predominately by electrochemical testing with subsequent micro-structural analysis. In order to be able to develop better SOFCs, it is important to understand how the measured electrochemical performance depends......Solid oxide fuel cells (SOFCs) are able to produce electricity and heat from hydrogen- or carbon-containing fuels with high efficiencies and are considered important cornerstones for future sustainable energy systems. Performance, activation and degradation processes are crucial parameters...... on materials and structural properties, preferably at the atomic level. A characterization of these properties under operation is desired. As SOFCs operate at temperatures around 1073 K, this is a challenge. A spectroelectrochemical cell was designed that is able to study SOFCs at operating temperatures...

Electricity generation by microbial fuel cells fuelled with wheat straw hydrolysate

DEFF Research Database (Denmark)

Thygesen, Anders; Poulsen, Finn Willy; Angelidaki, Irini

2011-01-01

Electricity production from microbial fuel cells fueled with hydrolysate produced by hydrothermal treatment of wheat straw can achieve both energy production and domestic wastewater purification. The hydrolysate contained mainly xylan, carboxylic acids, and phenolic compounds. Power generation...... in 95% degradation of the xylan and glucan. The study demonstrates that lignocellulosic hydrolysate can be used for co-treatment with domestic wastewater for power generation in microbial fuel cells....... density with the hydrolysate was higher than the one with only xylan (120 mW m−2) and carboxylic acids as fuel. The higher power density can be caused by the presence of phenolic compounds in the hydrolysates, which could mediate electron transport. Electricity generation with the hydrolysate resulted...

Optimization of Fuel Cell System Operating Conditions for Fuel Cell Vehicles

OpenAIRE

Zhao, Hengbing; Burke, Andy

2008-01-01

Proton Exchange Membrane fuel cell (PEMFC) technology for use in fuel cell vehicles and other applications has been intensively developed in recent decades. Besides the fuel cell stack, air and fuel control and thermal and water management are major challenges in the development of the fuel cell for vehicle applications. The air supply system can have a major impact on overall system efficiency. In this paper a fuel cell system model for optimizing system operating conditions was developed wh...

UPS Project for GSM base stations with a fuel cell (PEM fuel cell back-up system) - Final report; Projekt USV fuer GSM-Basisstationen mit BZ (PEM fuel cell back-up system) - Abschlussbericht

Energy Technology Data Exchange (ETDEWEB)

Trachte, U.

2007-07-01

The University of applied sciences HTA Lucerne designed a prototype of an uninterruptible power supply (UPS) with Fuel Cell technology instead of lead-acid batteries and put it into operation. The delayed start-up of the Fuel Cell was bridged with ultra capacitor technology. In a first project stage the system was designed, assembled and tested in laboratory. In a second stage the installation was connected to a real base station of a telecommunication antenna and put to field tests for one year. The field test included monthly simulations of power failure with antenna load of about 2.4 kW as well as tests with external load up to 8.5 kW to establish the characteristic diagram. Hydrogen was provided by two 50 l pressure tanks. The full quantity of hydrogen secured a stand-alone operation of the Fuel Cell system for about 6 hours under antenna load. The results of the 101 grid-failure simulations demonstrate a very reliable start-up behaviour of the Fuel Cell System. Also during a real power failure due to a thunderstorm the installation provided the demanded power without any problem. The total duration of operation of the Fuel Cell during the field tests was 39 hours. No degradation could be noticed. The project takes place in collaboration with the industrial partners APC Industrial Systems, as a producer and market leader of UPS-Systems, and Swisscom Mobile AG, as a user of UPS-systems in telecommunications. Following the good results and in order to get more experience in long-term operation of the Fuel Cell system the tests will go on for two more years. (author)

CERDEC Fuel Cell Team: Military Transitions for Soldier Fuel Cells

Science.gov (United States)

2008-10-27

Fuel Cell (DMFC) (PEO Soldier) Samsung: 20W DMFC (CRADA) General Atomics & Jadoo: 50W Ammonia Borane Fueled PEMFC Current Fuel Cell Team Efforts...Continued Ardica: 20W Wearable PEMFC operating on Chemical Hydrides Spectrum Brands w/ Rayovac: Hydrogen Generators and Alkaline Fuel Cells for AA...100W Ammonia Borane fueled PEMFC Ultralife: 150W sodium borohydride fueled PEMFC Protonex: 250W RMFC and Power Manager (ARO) NanoDynamics: 250W SOFC

Experimental study of cell reversal of a high temperature polymer electrolyte membrane fuel cell caused by H2 starvation

DEFF Research Database (Denmark)

Zhou, Fan; Andreasen, Søren Juhl; Kær, Søren Knudsen

2015-01-01

Operation under fuel starvation has been proved to be harmful to the fuel cell by causing severe and irreversible degradation. To characterize the behaviors of the high temperature PEM fuel cell under fuel starvation conditions, the cell voltage and local current density is measured simultaneously...... under different H2 stoichiometries below 1.0 and at different current loads. The experimental results show that the cell voltage decreases promptly when the H2 stoichiometry decreases to below 1.0. Negative cell voltage can be observed which indicates cell reversal. The local current density starts...... to diverge when the cell voltage decreases. In the H2 upstream regions the current densities show an increasing trend, while those in the H2 downstream regions show a decreasing trend. Consequently, the current density distribution becomes very uneven. The current density is the highest in the upstream...

SOFC direct fuelling with high-methane gases: Optimal strategies for fuel dilution and upgrade to avoid quick degradation

International Nuclear Information System (INIS)

Baldinelli, A.; Barelli, L.; Bidini, G.; Di Michele, A.; Vivani, R.

2016-01-01

Highlights: • SOFCs are operated on natural gas and biogas direct feeding. • Methane partial oxidation and dry reforming are compared. • The optimal oxygen-to-carbon stoichiometry to avoid degradation is determined for both natural gas and biogas. • NiYSZ anodes degradation mechanisms are investigated though SEM-EDX and XRD. - Abstract: In the outlook of the transition to the carbon-free society, low-carbon gases, such as natural gas or biogas, are very promising. The first is commonly used for stationary applications based on Solid Oxide Fuel Cells (SOFCs) equipped with external reformers. Similar installations are required when the SOFC is run on biogas. Yet, high SOFC operative temperature enables internal decomposition of light hydrocarbons, therefore allowing the suppression of external reforming. Evidently, this brings about benefits in terms of system complexity and cost reduction. Nonetheless, unlike reformate fuels, direct exposure to large amount of methane favours SOFC anodes degradation. Implementing a systematic experimental approach, this paper aims at determining a simple operative strategy to carry out direct feeding without meeting with quick degradation issues, producing interesting outcomes with regards to the management of SOFC-based systems. Particularly, the regulation of the oxygen-to-carbon (O/C) relative fraction of the fuel through air addition to natural gas and partial CO_2 separation from biogas is helpful in the prevention of those mechanisms. In this study, NiYSZ anode SOFCs are exposed to air-diluted natural gas and upgraded biogas, featuring O/C between 0.2 and 1.2. Tracing these cases, at 800 °C and 500 mA/cm"2 constant load, cell performances are measured over a time interval of 100 h. Finally, post-mortem analysis is performed on the specimens to investigate material morphological changes after the exposure to high-methane fuels. Results showed that O/C = 0.8 (+63% air) is the best case to employ air-diluted natural gas

Assessment of the cathode contribution to the degradation of anode-supported solid oxide fuel cells

DEFF Research Database (Denmark)

Hagen, Anke; Liu, Yi-Lin; Barfod, Rasmus

2008-01-01

The degradation of anode-supported cells was studied over 1500 h as a function of cell polarization either in air or oxygen on the cathode side. Based on impedance analysis, contributions of the anode and cathode to the increase of total resistance were assigned. Accordingly, the degradation rates...... of the cathode were strongly dependent on the pO(2). Microstructural analysis of the cathode/electrolyte interface carried out after removal of the cathode showed craters on the electrolyte surface where the lanthanum strontium manganite (LSM) particles had been located. The changes of shape and size...... of these craters observed after testing correlated with the cell voltage degradation rates. The results can be interpreted in terms of element redistribution at the cathode/electrolyte interface and formation of foreign phases giving rise to a weakening of local contact points of the LSM cathode and yttria...

A comprehensive review of PBI-based high temperature PEM fuel cells

DEFF Research Database (Denmark)

Simon Araya, Samuel; Zhou, Fan; Liso, Vincenzo

2016-01-01

of their design and characterization techniques at single cell, stack and system levels is given. The state-of-the-art concepts of different degradation mechanisms and methods of their mitigation are also discussed. Moreover, accelerated stress testing (AST) procedures for HT-PEMFCs available in literature...... fuel cell faults for targeted interventions based on the observed conditions to prevent sudden failures and to prolong the fuel cell's lifetime. However, the technology is still under development and robust on-line diagnostics tools are hardly available. Currently, mitigation is mainly done based......The current status on the understanding of the various operational aspects of high temperature proton exchange membrane fuel cells (HT-PEMFC) has been summarized. The paper focuses on phosphoric acid-doped polybenzimidazole (PBI)-based HT-PEMFCs and an overview of the common practices...

Annual Report: Advanced Energy Systems Fuel Cells (30 September 2013)

Energy Technology Data Exchange (ETDEWEB)

Gerdes, Kirk; Richards, George

2014-04-16

The comprehensive research plan for Fuel Cells focused on Solid State Energy Conversion Alliance (SECA) programmatic targets and included objectives in two primary and focused areas: (1) investigation of degradation modes exhibited by the anode/electrolyte/cathode (AEC), development of computational models describing the associated degradation rates, and generation of a modeling tool predicting long term AEC degradation response; and (2) generation of novel electrode materials and microstructures and implementation of the improved electrode technology to enhance performance. In these areas, the National Energy Technology Laboratory (NETL) Regional University Alliance (RUA) team has completed and reported research that is significant to the SECA program, and SECA continued to engage all SECA core and SECA industry teams. Examination of degradation in an operational solid oxide fuel cell (SOFC) requires a logical organization of research effort into activities such as fundamental data gathering, tool development, theoretical framework construction, computational modeling, and experimental data collection and validation. Discrete research activity in each of these categories was completed throughout the year and documented in quarterly reports, and researchers established a framework to assemble component research activities into a single operational modeling tool. The modeling framework describes a scheme for categorizing the component processes affecting the temporal evolution of cell performance, and provides a taxonomical structure of known degradation processes. The framework is an organizational tool that can be populated by existing studies, new research completed in conjunction with SECA, or independently obtained. The Fuel Cell Team also leveraged multiple tools to create cell performance and degradation predictions that illustrate the combined utility of the discrete modeling activity. Researchers first generated 800 continuous hours of SOFC experimental

Nanofluidic fuel cell

Science.gov (United States)

Lee, Jin Wook; Kjeang, Erik

2013-11-01

Fuel cells are gaining momentum as a critical component in the renewable energy mix for stationary, transportation, and portable power applications. State-of-the-art fuel cell technology benefits greatly from nanotechnology applied to nanostructured membranes, catalysts, and electrodes. However, the potential of utilizing nanofluidics for fuel cells has not yet been explored, despite the significant opportunity of harnessing rapid nanoscale reactant transport in close proximity to the reactive sites. In the present article, a nanofluidic fuel cell that utilizes fluid flow through nanoporous media is conceptualized and demonstrated for the first time. This transformative concept captures the advantages of recently developed membraneless and catalyst-free fuel cell architectures paired with the enhanced interfacial contact area enabled by nanofluidics. When compared to previously reported microfluidic fuel cells, the prototype nanofluidic fuel cell demonstrates increased surface area, reduced activation overpotential, superior kinetic characteristics, and moderately enhanced fuel cell performance in the high cell voltage regime with up to 14% higher power density. However, the expected mass transport benefits in the high current density regime were constrained by high ohmic cell resistance, which could likely be resolved through future optimization studies.

Bringing fuel cells to reality and reality to fuel cells: A systems perspective on the use of fuel cells

International Nuclear Information System (INIS)

Saxe, Maria

2008-10-01

The hopes and expectations on fuel cells are high and sometimes unrealistically positive. However, as an emerging technology, much remains to be proven and the proper use of the technology in terms of suitable applications, integration with society and extent of use is still under debate. This thesis is a contribution to the debate, presenting results from two fuel cell demonstration projects, looking into the introduction of fuel cells on the market, discussing the prospects and concerns for the near-term future and commenting on the potential use in a future sustainable energy system. Bringing fuel cells to reality implies finding near-term niche applications and markets where fuel cell systems may be competitive. In a sense fuel cells are already a reality as they have been demonstrated in various applications world-wide. However, in many of the envisioned applications fuel cells are far from being competitive and sometimes also the environmental benefit of using fuel cells in a given application may be questioned. Bringing reality to fuel cells implies emphasising the need for realistic expectations and pointing out that the first markets have to be based on the currently available technology and not the visions of what fuel cells could be in the future. The results from the demonstration projects show that further development and research on especially the durability for fuel cell systems is crucial and a general recommendation is to design the systems for high reliability and durability rather than striving towards higher energy efficiencies. When sufficient reliability and durability are achieved, fuel cell systems may be introduced in niche markets where the added values presented by the technology compensate for the initial high cost

Corrosion in batteries and fuel-cell power sources

International Nuclear Information System (INIS)

Cieslak, W.R.

1987-01-01

Batteries and fuel cells, as electrochemical power sources, provide energy through controlled redox reactions. Because these devices contain electrochemically active components, they place metals in contact with environments in which the metals may corrode. The shelf lives of batteries, particularly those that operate at ambient temperatures depend on very slow rates of corrosion of the electrode materials at open circuit. The means of reducing this corrosion must also be evaluated for its influence on performance. A second major corrosion consideration in electrochemical power sources involves the hardware. Again, shelf lives and service lives depend on very good corrosion resistance of the containment materials and inactive components, such as separators. In those systems in which electrolyte purity is important, even small amounts of corrosion that have not lessened structural integrity can degrade performance. There is a wide variety of batteries and fuel cells, and new systems are constantly under development. Therefore, to illustrate the types of corrosion phenomena that occur, this article will discuss the following systems: lead-acid batteries, alkaline batteries (in terms of the sintered nickel electrode only), lithium ambient-temperature batteries, aluminum/air batteries, sodium/sulfur batteries, phosphoric acid (H/sub 3/PO/sub 4/) fuel cells, and molten carbonate fuel cells

Fuel Cell Electric Vehicle Evaluations | Hydrogen and Fuel Cells | NREL

Science.gov (United States)

Electric Vehicle Evaluations Fuel Cell Electric Vehicle Evaluations NREL's technology validation team analyzes hydrogen fuel cell electric vehicles (FCEVs) operating in a real-world setting to include commercial FCEVs for the first time. Current fuel cell electric vehicle evaluations build on the

Development of molten carbonate fuel cells for power generation

Science.gov (United States)

1980-04-01

The broad and comprehensive program included elements of system definition, cell and system modeling, cell component development, cell testing in pure and contaminated environments, and the first stages of technology scale up. Single cells, with active areas of 45 sq cm and 582 sq cm, were operated at 650 C and improved to state of the art levels through the development of cell design concepts and improved electrolyte and electrode components. Performance was shown to degrade by the presence of fuel contaminants, such as sulfur and chlorine, and due to changes in electrode structure. Using conventional hot press fabrication techniques, electrolyte structures up to 20" x 20" were fabricated. Promising approaches were developed for nonhot pressed electrolyte structure fabrication and a promising electrolyte matrix material was identified. This program formed the basis for a long range effort to realize the benefits of molten carbonate fuel cell power plants.

Ni-YSZ solid oxide fuel cell anode behavior upon redox cycling based on electrical characterization

DEFF Research Database (Denmark)

Klemensø, Trine; Mogensen, Mogens Bjerg

2007-01-01

Nickel (Ni)—yttria-stabilized zirconia (YSZ) cermets are a prevalent material used for solid oxide fuel cells. The cermet degrades upon redox cycling. The degradation is related to microstructural changes, but knowledge of the mechanisms has been limited. Direct current conductivity measurements...

Fuel cells science and engineering. Materials, processes, systems and technology. Vol. 1

Energy Technology Data Exchange (ETDEWEB)

Stolten, Detlef; Emonts, Bernd (eds.) [Forschungszentrum Juelich GmbH (DE). Inst. fuer Energieforschung (IEF), Brennstoffzellen (IEF-3)

2012-07-01

-Temperature Fuel Cells (Juergen Wackerl); 20: Degradation Caused by Dynamic Operation and Starvation Conditions (Jan Hendrik Ohs, Ulrich S. Sauter and Sebastian Maass). PART IV: Quality Assurance. Chapter 21: Quality Assurance for Characterizing Low-Temperature Fuel Cells (Viktor Hacker, Eva Wallnoefer-Ogris, Georgios Tsotridis and Thomas Malkow); 22: Methodologies for Fuel Cell Process Engineering (Remzi Can Samsun and Ralf Peters).

Constant strength fuel-fuel cell

International Nuclear Information System (INIS)

Vaseen, V.A.

1980-01-01

A fuel cell is an electrochemical apparatus composed of both a nonconsumable anode and cathode; and electrolyte, fuel oxidant and controls. This invention guarantees the constant transfer of hydrogen atoms and their respective electrons, thus a constant flow of power by submergence of the negative electrode in a constant strength hydrogen furnishing fuel; when said fuel is an aqueous absorbed hydrocarbon, such as and similar to ethanol or methnol. The objective is accomplished by recirculation of the liquid fuel, as depleted in the cell through specific type membranes which pass water molecules and reject the fuel molecules; thus concentrating them for recycle use

Fuels processing for transportation fuel cell systems

Science.gov (United States)

Kumar, R.; Ahmed, S.

Fuel cells primarily use hydrogen as the fuel. This hydrogen must be produced from other fuels such as natural gas or methanol. The fuel processor requirements are affected by the fuel to be converted, the type of fuel cell to be supplied, and the fuel cell application. The conventional fuel processing technology has been reexamined to determine how it must be adapted for use in demanding applications such as transportation. The two major fuel conversion processes are steam reforming and partial oxidation reforming. The former is established practice for stationary applications; the latter offers certain advantages for mobile systems and is presently in various stages of development. This paper discusses these fuel processing technologies and the more recent developments for fuel cell systems used in transportation. The need for new materials in fuels processing, particularly in the area of reforming catalysis and hydrogen purification, is discussed.

SOLID STATE ENERGY CONVERSION ALLIANCE (SECA) SOLID OXIDE FUEL CELL PROGRAM

Energy Technology Data Exchange (ETDEWEB)

Nguyen Minh; Jim Powers

2003-10-01

This report summarizes the work performed for April 2003--September 2003 reporting period under Cooperative Agreement DE-FC26-01NT41245 for the U.S. Department of Energy, National Energy Technology Laboratory (DOE/NETL) entitled ''Solid State Energy Conversion Alliance (SECA) Solid oxide Fuel Cell Program''. During this reporting period, the conceptual system design activity was completed. The system design, including strategies for startup, normal operation and shutdown, was defined. Sealant and stack materials for the solid oxide fuel cell (SOFC) stack were identified which are capable of meeting the thermal cycling and degradation requirements. A cell module was tested which achieved a stable performance of 0.238 W/cm{sup 2} at 95% fuel utilization. The external fuel processor design was completed and fabrication begun. Several other advances were made on various aspects of the SOFC system, which are detailed in this report.

Final Report - Durable Catalysts for Fuel Cell Protection during Transient Conditions

Energy Technology Data Exchange (ETDEWEB)

Atanasoski, Radoslav [3M Company, St. Paul, MN (United States); van der Vliet, Dennis [3M Company, St. Paul, MN (United States); Cullen, David [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Atanasoska, Ljiljana [3M Company, St. Paul, MN (United States)

2015-01-26

The objective of this project was to develop catalysts that will enable proton exchange membranes (PEM) fuel cell systems to weather the damaging conditions in the fuel cell at voltages beyond the thermodynamic stability of water during the transient periods of start-up/shut-down and fuel starvation. Such catalysts are required to make it possible for the fuel cell to satisfy the 2015 DOE targets for performance and durability. The project addressed a key issue of importance for successful transition of PEM fuel cell technology from development to pre-commercial phase. This issue is the failure of the catalyst and the other thermodynamically unstable membrane electrode assembly (MEA) components during start-up/shut-down and local fuel starvation at the anode, commonly referred to as transient conditions. During these periods the electrodes can reach potentials higher than the usual 1.23V upper limit during normal operation. The most logical way to minimize the damage from such transient events is to minimize the potential seen by the electrodes. At lower positive potentials, increased stability of the catalysts themselves and reduced degradation of the other MEA components is expected.

Fuel cells for electricity generation from carbonaceous fuels

Energy Technology Data Exchange (ETDEWEB)

Ledjeff-Hey, K; Formanski, V; Roes, J [Gerhard-Mercator- Universitaet - Gesamthochschule Duisburg, Fachbereich Maschinenbau/Fachgebiet Energietechnik, Duisburg (Germany); Heinzel, A [Fraunhofer Inst. for Solar Energy Systems (ISE), Freiburg (Germany)

1998-09-01

Fuel cells, which are electrochemical systems converting chemical energy directly into electrical energy with water and heat as by-products, are of interest as a means of generating electricity which is environmentally friendly, clean and highly efficient. They are classified according to the electrolyte used. The main types of cell in order of operating temperature are described. These are: alkaline fuel cells, the polymer electrolyte membrane fuel cell (PEMFC); the phosphoric acid fuel cell (PAFC); the molten carbonate fuel cell (MCFC); the solid oxide fuel cell (SOFC). Applications depend on the type of cell and may range from power generation on a large scale to mobile application in cars or portable systems. One of the most promising options is the PEM-fuel cell stack where there has been significant improvement in power density in recent years. The production from carbonaceous fuels and purification of the cell fuel, hydrogen, is considered. Of the purification methods available, hydrogen separation by means of palladium alloy membranes seems particular effective in reducing CO concentrations to the low levels required for PEM cells. (UK)

Ni-YSZ solid oxide fuel cell anode behavior upon redox cycling based on electrical characterization

DEFF Research Database (Denmark)

Klemensø, Trine; Mogensen, Mogens Bjerg

2006-01-01

Ni-YSZ cermets are a prevalent material used for solid oxide fuel cells. However, the cermet degrades upon redox cycling. The degradation is related to microstructural changes, but knowledge of the mechanisms has been limited. DC conductivity measurements were performed on cermets and cermets...

Fuel cell opportunities

Energy Technology Data Exchange (ETDEWEB)

Harris, K. [Hydrogenics Corporation, Mississauga, ON (Canada)

2002-07-01

The opportunities for fuel cell development are discussed. Fuel cells are highly efficient, reliable and require little maintenance. They also produce virtually zero emissions. The author stated that there are some complicated issues to resolve before fuel cells can be widely used. These include hydrogen availability and infrastructure. While the cost of fuel cells is currently very high, these costs are constantly coming down. The industry is still in the early stages of development. The driving forces for the development of fuel cells are: deregulation of energy markets, growing expectations for distributed power generation, discontinuity between energy supply and demand, and environmental concerns. 12 figs.

Corrosion Studies of Platinum Nano-Particles for Fuel Cells

DEFF Research Database (Denmark)

Shim, Signe Sarah

The main focus of the present thesis is on corrosion and prevention of corrosion of platinum particles supported on carbon. This is important for instance in connection with start up and shutdown of fuel cells. The degradation mechanism of platinum particles supported on carbon has been character......The main focus of the present thesis is on corrosion and prevention of corrosion of platinum particles supported on carbon. This is important for instance in connection with start up and shutdown of fuel cells. The degradation mechanism of platinum particles supported on carbon has been...... characterized during oxygen reduction reaction (ORR) condition using identical location (IL) transmission electron microscopy (TEM). A TEM grid was used as the working electrode in an electrochemical setup allowing a direct correlation between the electrochemical response and the TEM analysis. The main results...... thirds and one monolayer of gold on platinum supported on carbon were synthesized by an inverse micelle method. The results obtained appear independent of the gold coverage. It has been shown that the electrochemical active surface areas of the platinum and platinum gold particles synthesized...

Fuel cells

International Nuclear Information System (INIS)

Niederdoeckl, J.

2001-01-01

Europe has at present big hopes on the fuel cells technology, in comparison with other energy conversion technologies, this technology has important advantages, for example: high efficiency, very low pollution and parallel use of electric and thermal energy. Preliminary works for fuel cells developing and its commercial exploitation are at full speed; until now the European Union has invested approx. 1.7 billion Schillings, 60 relevant projects are being executed. The Austrian industry is interested in applying this technique to drives, thermal power stations and the miniature fuel cells as replacement of batteries in electronic products (Notebooks, mobile telephones, etc.). A general description of the historic development of fuel cells including the main types is given as well as what is the situation in Austria. (nevyjel)

Fuel Cell Demonstration Program

Energy Technology Data Exchange (ETDEWEB)

Gerald Brun

2006-09-15

In an effort to promote clean energy projects and aid in the commercialization of new fuel cell technologies the Long Island Power Authority (LIPA) initiated a Fuel Cell Demonstration Program in 1999 with six month deployments of Proton Exchange Membrane (PEM) non-commercial Beta model systems at partnering sites throughout Long Island. These projects facilitated significant developments in the technology, providing operating experience that allowed the manufacturer to produce fuel cells that were half the size of the Beta units and suitable for outdoor installations. In 2001, LIPA embarked on a large-scale effort to identify and develop measures that could improve the reliability and performance of future fuel cell technologies for electric utility applications and the concept to establish a fuel cell farm (Farm) of 75 units was developed. By the end of October of 2001, 75 Lorax 2.0 fuel cells had been installed at the West Babylon substation on Long Island, making it the first fuel cell demonstration of its kind and size anywhere in the world at the time. Designed to help LIPA study the feasibility of using fuel cells to operate in parallel with LIPA's electric grid system, the Farm operated 120 fuel cells over its lifetime of over 3 years including 3 generations of Plug Power fuel cells (Lorax 2.0, Lorax 3.0, Lorax 4.5). Of these 120 fuel cells, 20 Lorax 3.0 units operated under this Award from June 2002 to September 2004. In parallel with the operation of the Farm, LIPA recruited government and commercial/industrial customers to demonstrate fuel cells as on-site distributed generation. From December 2002 to February 2005, 17 fuel cells were tested and monitored at various customer sites throughout Long Island. The 37 fuel cells operated under this Award produced a total of 712,635 kWh. As fuel cell technology became more mature, performance improvements included a 1% increase in system efficiency. Including equipment, design, fuel, maintenance

Catalyst Degradation Under Potential Cycling as an Accelerated Stress Test for PBI-Based High-Temperature PEM Fuel Cells - Effect of Humidification

DEFF Research Database (Denmark)

Søndergaard, Tonny; Cleemann, Lars Nilausen; Zhong, Lijie

2018-01-01

In the present work, high-temperature polymer electrolyte membrane fuel cells were subjected to accelerated stress tests of 30,000 potential cycles between 0.6 and 1.0 V at 160 textdegreeC (133 h cycling time). The effect that humidity has on the catalyst durability was studied by testing either...... with or without humidification of the nitrogen that was used as cathode gas during cycling segments. Pronounced degradation was seen from the polarization curves in both cases, though permanent only in the humidified case. In the unhumidified case, the performance loss was more or less recoverable following 24 h...

Fuel Cells

DEFF Research Database (Denmark)

Smith, Anders; Pedersen, Allan Schrøder

2014-01-01

Fuel cells have been the subject of intense research and development efforts for the past decades. Even so, the technology has not had its commercial breakthrough yet. This entry gives an overview of the technological challenges and status of fuel cells and discusses the most promising applications...... of the different types of fuel cells. Finally, their role in a future energy supply with a large share of fluctuating sustainable power sources, e.g., solar or wind, is surveyed....

High-energy-density hydrogen-halogen fuel cells for advanced military applications

International Nuclear Information System (INIS)

Balko, E.N.; McElroy, J.F.

1981-01-01

It is pointed out that hydrogen-halogen fuel cell systems are particularly suited for an employment as ground power sources for military applications. The large cell potential and reversible characteristics of the H 2 Cl 2 and H 2 Br 2 couples permit high energy storage density and efficient energy conversion. When used as flow batteries, the fluid nature of the reactants in the hydrogen-halogen systems has several advantages over power sources which involve solid phases. Very deep discharge is possible without degradation of subsequent performance, and energy storage capacity is limited only by the external reactant storage volume. Very rapid chemical recharging is possible through replenishment of the reactant supply. A number of H 2 Cl 2 and H 2 Br 2 fuel cell systems have been studied. These systems use the same solid polymer electrolyte (SPE) cell technology originally developed for H2/O2 fuel cells. The results of the investigation are illustrated with the aid of a number of graphs

Handbook of fuel cell performance

Energy Technology Data Exchange (ETDEWEB)

Benjamin, T.G.; Camara, E.H.; Marianowski, L.G.

1980-05-01

The intent of this document is to provide a description of fuel cells, their performances and operating conditions, and the relationship between fuel processors and fuel cells. This information will enable fuel cell engineers to know which fuel processing schemes are most compatible with which fuel cells and to predict the performance of a fuel cell integrated with any fuel processor. The data and estimates presented are for the phosphoric acid and molten carbonate fuel cells because they are closer to commercialization than other types of fuel cells. Performance of the cells is shown as a function of operating temperature, pressure, fuel conversion (utilization), and oxidant utilization. The effect of oxidant composition (for example, air versus O/sub 2/) as well as fuel composition is examined because fuels provided by some of the more advanced fuel processing schemes such as coal conversion will contain varying amounts of H/sub 2/, CO, CO/sub 2/, CH/sub 4/, H/sub 2/O, and sulfur and nitrogen compounds. A brief description of fuel cells and their application to industrial, commercial, and residential power generation is given. The electrochemical aspects of fuel cells are reviewed. The phosphoric acid fuel cell is discussed, including how it is affected by operating conditions; and the molten carbonate fuel cell is discussed. The equations developed will help systems engineers to evaluate the application of the phosphoric acid and molten carbonate fuel cells to commercial, utility, and industrial power generation and waste heat utilization. A detailed discussion of fuel cell efficiency, and examples of fuel cell systems are given.

Ammonia as a Suitable Fuel for Fuel Cells

International Nuclear Information System (INIS)

Lan, Rong; Tao, Shanwen

2014-01-01

Ammonia, an important basic chemical, is produced at a scale of 150 million tons per year. Half of hydrogen produced in chemical industry is used for ammonia production. Ammonia containing 17.5 wt% hydrogen is an ideal carbon-free fuel for fuel cells. Compared to hydrogen, ammonia has many advantages. In this mini-review, the suitability of ammonia as fuel for fuel cells, the development of different types of fuel cells using ammonia as the fuel and the potential applications of ammonia fuel cells are briefly reviewed.

Fault detection and isolation of high temperature proton exchange membrane fuel cell stack under the influence of degradation

DEFF Research Database (Denmark)

Jeppesen, Christian; Araya, Samuel Simon; Sahlin, Simon Lennart

2017-01-01

This study proposes a data-drive impedance-based methodology for fault detection and isolation of low and high cathode stoichiometry, high CO concentration in the anode gas, high methanol vapour concentrations in the anode gas and low anode stoichiometry, for high temperature PEM fuel cells....... The fault detection and isolation algorithm is based on an artificial neural network classifier, which uses three extracted features as input. Two of the proposed features are based on angles in the impedance spectrum, and are therefore relative to specific points, and shown to be independent of degradation......, contrary to other available feature extraction methods in the literature. The experimental data is based on a 35 day experiment, where 2010 unique electrochemical impedance spectroscopy measurements were recorded. The test of the algorithm resulted in a good detectability of the faults, except for high...

Methanol Fuel Cell

Science.gov (United States)

Voecks, G. E.

1985-01-01

In proposed fuel-cell system, methanol converted to hydrogen in two places. External fuel processor converts only part of methanol. Remaining methanol converted in fuel cell itself, in reaction at anode. As result, size of fuel processor reduced, system efficiency increased, and cost lowered.

Fuel economy of hybrid fuel-cell vehicles

Science.gov (United States)

Ahluwalia, Rajesh K.; Wang, X.; Rousseau, A.

The potential improvement in fuel economy of a mid-size fuel-cell vehicle by combining it with an energy storage system has been assessed. An energy management strategy is developed and used to operate the direct hydrogen, pressurized fuel-cell system in a load-following mode and the energy storage system in a charge-sustaining mode. The strategy places highest priority on maintaining the energy storage system in a state where it can supply unanticipated boost power when the fuel-cell system alone cannot meet the power demand. It is found that downsizing a fuel-cell system decreases its efficiency on a drive cycle which is compensated by partial regenerative capture of braking energy. On a highway cycle with limited braking energy the increase in fuel economy with hybridization is small but on the stop-and-go urban cycle the fuel economy can improve by 27%. On the combined highway and urban drive cycles the fuel economy of the fuel-cell vehicle is estimated to increase by up to 15% by hybridizing it with an energy storage system.

Direct Carbon Fuel Cell System Utilizing Solid Carbonaceous Fuels

Energy Technology Data Exchange (ETDEWEB)

Turgut Gur

2010-04-30

This 1-year project has achieved most of its objective and successfully demonstrated the viability of the fluidized bed direct carbon fuel cell (FB-DCFC) approach under development by Direct Carbon technologies, LLC, that utilizes solid carbonaceous fuels for power generation. This unique electrochemical technology offers high conversion efficiencies, produces proportionately less CO{sub 2} in capture-ready form, and does not consume or require water for gasification. FB-DCFC employs a specialized solid oxide fuel cell (SOFC) arrangement coupled to a Boudouard gasifier where the solid fuel particles are fluidized and reacted by the anode recycle gas CO{sub 2}. The resulting CO is electrochemically oxidized at the anode. Anode supported SOFC structures employed a porous Ni cermet anode layer, a dense yttria stabilized zirconia membrane, and a mixed conducting porous perovskite cathode film. Several kinds of untreated solid fuels (carbon and coal) were tested in bench scale FBDCFC prototypes for electrochemical performance and stability testing. Single cells of tubular geometry with active areas up to 24 cm{sup 2} were fabricated. The cells achieved high power densities up to 450 mW/cm{sup 2} at 850 C using a low sulfur Alaska coal char. This represents the highest power density reported in the open literature for coal based DCFC. Similarly, power densities up to 175 mW/cm{sup 2} at 850 C were demonstrated with carbon. Electrical conversion efficiencies for coal char were experimentally determined to be 48%. Long-term stability of cell performance was measured under galvanostatic conditions for 375 hours in CO with no degradation whatsoever, indicating that carbon deposition (or coking) does not pose any problems. Similar cell stability results were obtained in coal char tested for 24 hours under galvanostatic conditions with no sign of sulfur poisoning. Moreover, a 50-cell planar stack targeted for 1 kW output was fabricated and tested in 95% CO (balance CO{sub 2

Fuel cells : a viable fossil fuel alternative

Energy Technology Data Exchange (ETDEWEB)

Paduada, M.

2007-02-15

This article presented a program initiated by Natural Resources Canada (NRCan) to develop proof-of-concept of underground mining vehicles powered by fuel cells in order to eliminate emissions. Recent studies on American and Canadian underground mines provided the basis for estimating the operational cost savings of switching from diesel to fuel cells. For the Canadian mines evaluated, the estimated ventilation system operating cost reductions ranged from 29 per cent to 75 per cent. In order to demonstrate the viability of a fuel cell-powered vehicle, NRCan has designed a modified Caterpillar R1300 loader with a 160 kW hybrid power plant in which 3 stacks of fuel cells deliver up to 90 kW continuously, and a nickel-metal hydride battery provides up to 70 kW. The battery subsystem transiently boosts output to meet peak power requirements and also accommodates regenerative braking. Traction for the loader is provided by a brushless permanent magnet traction motor. The hydraulic pump motor is capable of a 55 kW load continuously. The loader's hydraulic and traction systems are operated independently. Future fuel cell-powered vehicles designed by the program may include a locomotive and a utility vehicle. Future mines running their operations with hydrogen-fueled equipment may also gain advantages by employing fuel cells in the operation of handheld equipment such as radios, flashlights, and headlamps. However, the proton exchange membrane (PEM) fuel cells used in the project are prohibitively expensive. The catalytic content of a fuel cell can add hundreds of dollars per kW of electric output. Production of catalytic precious metals will be strongly connected to the scale of use and acceptance of fuel cells in vehicles. In addition, the efficiency of hydrogen production and delivery is significantly lower than the well-to-tank efficiency of many conventional fuels. It was concluded that an adequate hydrogen infrastructure will be required for the mining industry

Ammonia as a suitable fuel for fuel cells

Directory of Open Access Journals (Sweden)

Rong eLan

2014-08-01

Full Text Available Ammonia, an important basic chemical, is produced at a scale of 150 million tons per year. Half of hydrogen produced in chemical industry is used for ammonia production. Ammonia containing 17.5wt% hydrogen is an ideal carbon-free fuel for fuel cells. Compared to hydrogen, ammonia has many advantages. In this mini-review, the suitability of ammonia as fuel for fuel cells, the development of different types of fuel cells using ammonia as the fuel and the potential applications of ammonia fuel cells are briefly reviewed.

Evaluation of the performance degradation at PAFC effect of catalyst degradation on electrode performance

Energy Technology Data Exchange (ETDEWEB)

Nishizaki, K.; Uchida, H.; Watanabe, M. [Yamanashi Univ., Kofu (Japan)] [and others

1996-12-31

Aiming commercialization of Phosphoric Acid Fuel Cell (PAFC) power plant, many researches and developments have been contributed. Over 20000 hours operations have been demonstrated by many PAFC power plants. But there is no effective method for the estimation of lifetime of electrochemical cells without a practical long-term operation. Conducted by New Energy and Industrial Technology Development Organization (NEDO), cooperative research projects aiming development of PAFC lifetime estimation method have started since 1995 FY in Japan. As part of this project, this work has been performed to clarify basic phenomena of the performance degradation at PAFCs jointly by Yamanashi University, Phosphoric Acid Fuel Cell Technology Research Association (PAFC-TRA) and PAFC manufacturers (Toshiba Co., Mitsubishi Electric Co, Fuji Electric Co.). Among several main causes of the cell performance degradation, effects of catalyst degradation (reduction in metal surface area, dealloying, changes in catalyst support) on PAFC cathode performances are discussed in this work.

Fuel cell using a hydrogen generation system

Science.gov (United States)

Dentinger, Paul M.; Crowell, Jeffrey A. W.

2010-10-19

A system is described for storing and generating hydrogen and, in particular, a system for storing and generating hydrogen for use in an H.sub.2/O.sub.2 fuel cell. The hydrogen storage system uses beta particles from a beta particle emitting material to degrade an organic polymer material to release substantially pure hydrogen. In a preferred embodiment of the invention, beta particles from .sup.63Ni are used to release hydrogen from linear polyethylene.

Thermal degradation of ligno-cellulosic fuels. DSC and TGA studies

Energy Technology Data Exchange (ETDEWEB)

Leroy, V.; Cancellieri, D.; Leoni, E. [SPE-CNRS UMR 6134, University of Corsica, Campus Grossetti, BP 52, 20250 Corti (France)

2006-12-01

The scope of this work was to show the utility of thermal analysis and calorimetric experiments to study the thermal oxidative degradation of Mediterranean scrubs. We investigated the thermal degradation of four species; DSC and TGA were used under air sweeping to record oxidative reactions in dynamic conditions. Heat released and mass loss are important data to be measured for wildland fires modelling purpose and fire hazard studies on ligno-cellulosic fuels. Around 638 and 778K, two dominating and overlapped exothermic peaks were recorded in DSC and individualized using a experimental and numerical separation. This stage allowed obtaining the enthalpy variation of each exothermic phenomenon. As an application, we propose to classify the fuels according to the heat released and the rate constant of each reaction. TGA experiments showed under air two successive mass loss around 638 and 778K. Both techniques are useful in order to measure ignitability, combustibility and sustainability of forest fuels. (author)

Improved Flow-Field Structures for Direct Methanol Fuel Cells

Energy Technology Data Exchange (ETDEWEB)

Gurau, Bogdan [Nuvant Systems Inc., Crown Point, IN (United States)

2013-05-31

The direct methanol fuel cell (DMFC) is ideal if high energy-density liquid fuels are required. Liquid fuels have advantages over compressed hydrogen including higher energy density and ease of handling. Although state-of-the-art DMFCs exhibit manageable degradation rates, excessive fuel crossover diminishes system energy and power density. Although use of dilute methanol mitigates crossover, the concomitant lowering of the gross fuel energy density (GFED) demands a complex balance-of-plant (BOP) that includes higher flow rates, external exhaust recirculation, etc. An alternative approach is redesign of the fuel delivery system to accommodate concentrated methanol. NuVant Systems Inc. (NuVant) will maximize the GFED by design and assembly of a DMFC that uses near neat methanol. The approach is to tune the diffusion of highly concentrated methanol (to the anode catalytic layer) to the back-diffusion of water formed at the cathode (i.e. in situ generation of dilute methanol at the anode layer). Crossover will be minimized without compromising the GFED by innovative integration of the anode flow-field and the diffusion layer. The integrated flow-field-diffusion-layers (IFDLs) will widen the current and potential DMFC operating ranges and enable the use of cathodes optimized for hydrogen-air fuel cells.

An assessment of the energetic flows in a commercial PEM fuel-cell system

International Nuclear Information System (INIS)

Jovan, Vladimir; Perne, Matija; Petrovcic, Janko

2010-01-01

Some primary issues have not yet been fully investigated on the way towards the commercialization of fuel-cell-based systems (FCS), e.g., their actual efficiency, reliability, safety, degradation, maintainability, etc. This article deals with an estimation of the real energetic flows and the corresponding electrical efficiency of a commercial proton-exchange-membrane fuel-cell hydrogen-fed generator set (PEMFCS). The fuel-cell power system considered here is planned to be the source of both electrical and thermal energy in a mobile dwelling container unit with in-built fuel-cell-based cogeneration system, and for the design of a cogeneration unit the actual amount of disposable energy from the PEMFC unit should be estimated. The assessment of the actual energetic flows, the disposable energy and the consequent electrical efficiency of the case-study PEMFCS is carried out using commercial technical data for the PEMFCS.

Spectroelectrochemical cell for in situ studies of solid oxide fuel cells

International Nuclear Information System (INIS)

Hagen, Anke; Lund Traulsen, Marie; Kiebach, Wolff-Ragnar; Johansen, Bjoern Sejr

2012-01-01

Solid oxide fuel cells (SOFCs) are able to produce electricity and heat from hydrogen- or carbon-containing fuels with high efficiencies and are considered important cornerstones for future sustainable energy systems. Performance, activation and degradation processes are crucial parameters to control before the technology can achieve breakthrough. They have been widely studied, predominately by electrochemical testing with subsequent micro-structural analysis. In order to be able to develop better SOFCs, it is important to understand how the measured electrochemical performance depends on materials and structural properties, preferably at the atomic level. A characterization of these properties under operation is desired. As SOFCs operate at temperatures around 1073 K, this is a challenge. A spectroelectrochemical cell was designed that is able to study SOFCs at operating temperatures and in the presence of relevant gases. Simultaneous spectroscopic and electrochemical evaluation by using X-ray absorption spectroscopy and electrochemical impedance spectroscopy is possible. (orig.)

Fuel quality issues in stationary fuel cell systems.

Energy Technology Data Exchange (ETDEWEB)

Papadias, D.; Ahmed, S.; Kumar, R. (Chemical Sciences and Engineering Division)

2012-02-07

Fuel cell systems are being deployed in stationary applications for the generation of electricity, heat, and hydrogen. These systems use a variety of fuel cell types, ranging from the low temperature polymer electrolyte fuel cell (PEFC) to the high temperature solid oxide fuel cell (SOFC). Depending on the application and location, these systems are being designed to operate on reformate or syngas produced from various fuels that include natural gas, biogas, coal gas, etc. All of these fuels contain species that can potentially damage the fuel cell anode or other unit operations and processes that precede the fuel cell stack. These detrimental effects include loss in performance or durability, and attenuating these effects requires additional components to reduce the impurity concentrations to tolerable levels, if not eliminate the impurity entirely. These impurity management components increase the complexity of the fuel cell system, and they add to the system's capital and operating costs (such as regeneration, replacement and disposal of spent material and maintenance). This project reviewed the public domain information available on the impurities encountered in stationary fuel cell systems, and the effects of the impurities on the fuel cells. A database has been set up that classifies the impurities, especially in renewable fuels, such as landfill gas and anaerobic digester gas. It documents the known deleterious effects on fuel cells, and the maximum allowable concentrations of select impurities suggested by manufacturers and researchers. The literature review helped to identify the impurity removal strategies that are available, and their effectiveness, capacity, and cost. A generic model of a stationary fuel-cell based power plant operating on digester and landfill gas has been developed; it includes a gas processing unit, followed by a fuel cell system. The model includes the key impurity removal steps to enable predictions of impurity breakthrough

Fuel Cell Handbook, Fifth Edition

Energy Technology Data Exchange (ETDEWEB)

Energy and Environmental Solutions

2000-10-31

Progress continues in fuel cell technology since the previous edition of the Fuel Cell Handbook was published in November 1998. Uppermost, polymer electrolyte fuel cells, molten carbonate fuel cells, and solid oxide fuel cells have been demonstrated at commercial size in power plants. The previously demonstrated phosphoric acid fuel cells have entered the marketplace with more than 220 power plants delivered. Highlighting this commercial entry, the phosphoric acid power plant fleet has demonstrated 95+% availability and several units have passed 40,000 hours of operation. One unit has operated over 49,000 hours. Early expectations of very low emissions and relatively high efficiencies have been met in power plants with each type of fuel cell. Fuel flexibility has been demonstrated using natural gas, propane, landfill gas, anaerobic digester gas, military logistic fuels, and coal gas, greatly expanding market opportunities. Transportation markets worldwide have shown remarkable interest in fuel cells; nearly every major vehicle manufacturer in the U.S., Europe, and the Far East is supporting development. This Handbook provides a foundation in fuel cells for persons wanting a better understanding of the technology, its benefits, and the systems issues that influence its application. Trends in technology are discussed, including next-generation concepts that promise ultrahigh efficiency and low cost, while providing exceptionally clean power plant systems. Section 1 summarizes fuel cell progress since the last edition and includes existing power plant nameplate data. Section 2 addresses the thermodynamics of fuel cells to provide an understanding of fuel cell operation at two levels (basic and advanced). Sections 3 through 8 describe the six major fuel cell types and their performance based on cell operating conditions. Alkaline and intermediate solid state fuel cells were added to this edition of the Handbook. New information indicates that manufacturers have stayed

A Decade of Improvements for Solid Oxide Electrolysis Cells. Long-Term Degradation Rate from 40%/Kh to 0.4 % Kh

DEFF Research Database (Denmark)

Hauch, Anne; Brodersen, Karen; Chen, Ming

2016-01-01

Solid oxide electrolysis cells (SOEC) have the potential for efficient large-scale conversion from electrical energy to chemical energy stored in fuels, such as hydrogen or synthetic hydrocarbon fuels by use of well-known catalysis processes. Key issues for the break-through of this technology...... are to provide inexpensive, reliable, high performing and long-term stable SOEC for stack and system applications. At DTU Energy (formerly Department of Fuel Cells and Solid State Chemistry, Risø National Laboratory), research within SOEC for more than a decade has led to long-term degradation rates on cell...

Empirical membrane lifetime model for heavy duty fuel cell systems

Science.gov (United States)

Macauley, Natalia; Watson, Mark; Lauritzen, Michael; Knights, Shanna; Wang, G. Gary; Kjeang, Erik

2016-12-01

Heavy duty fuel cells used in transportation system applications such as transit buses expose the fuel cell membranes to conditions that can lead to lifetime-limiting membrane failure via combined chemical and mechanical degradation. Highly durable membranes and reliable predictive models are therefore needed in order to achieve the ultimate heavy duty fuel cell lifetime target of 25,000 h. In the present work, an empirical membrane lifetime model was developed based on laboratory data from a suite of accelerated membrane durability tests. The model considers the effects of cell voltage, temperature, oxygen concentration, humidity cycling, humidity level, and platinum in the membrane using inverse power law and exponential relationships within the framework of a general log-linear Weibull life-stress statistical distribution. The obtained model is capable of extrapolating the membrane lifetime from accelerated test conditions to use level conditions during field operation. Based on typical conditions for the Whistler, British Columbia fuel cell transit bus fleet, the model predicts a stack lifetime of 17,500 h and a membrane leak initiation time of 9200 h. Validation performed with the aid of a field operated stack confirmed the initial goal of the model to predict membrane lifetime within 20% of the actual operating time.

2009 Fuel Cell Market Report

Energy Technology Data Exchange (ETDEWEB)

Vincent, Bill [Breakthrough Technologies Inst., Washington, DC (United States); Gangi, Jennifer [Breakthrough Technologies Inst., Washington, DC (United States); Curtin, Sandra [Breakthrough Technologies Inst., Washington, DC (United States); Delmont, Elizabeth [Breakthrough Technologies Inst., Washington, DC (United States)

2010-11-01

Fuel cells are electrochemical devices that combine hydrogen and oxygen to produce electricity, water, and heat. Unlike batteries, fuel cells continuously generate electricity, as long as a source of fuel is supplied. Moreover, fuel cells do not burn fuel, making the process quiet, pollution-free and two to three times more efficient than combustion. Fuel cell systems can be a truly zero-emission source of electricity, if the hydrogen is produced from non-polluting sources. Global concerns about climate change, energy security, and air pollution are driving demand for fuel cell technology. More than 630 companies and laboratories in the United States are investing $1 billion a year in fuel cells or fuel cell component technologies. This report provides an overview of trends in the fuel cell industry and markets, including product shipments, market development, and corporate performance. It also provides snapshots of select fuel cell companies, including general.

Electrode materials for microbial fuel cells: nanomaterial approach

KAUST Repository

Mustakeem, Mustakeem

2015-11-05

Microbial fuel cell (MFC) technology has the potential to become a major renewable energy resource by degrading organic pollutants in wastewater. The performance of MFC directly depends on the kinetics of the electrode reactions within the fuel cell, with the performance of the electrodes heavily influenced by the materials they are made from. A wide range of materials have been tested to improve the performance of MFCs. In the past decade, carbon-based nanomaterials have emerged as promising materials for both anode and cathode construction. Composite materials have also shown to have the potential to become materials of choice for electrode manufacture. Various transition metal oxides have been investigated as alternatives to conventional expensive metals like platinum for oxygen reduction reaction. In this review, different carbon-based nanomaterials and composite materials are discussed for their potential use as MFC electrodes.

Electrode materials for microbial fuel cells: nanomaterial approach

KAUST Repository

Mustakeem, Mustakeem

2015-01-01

Microbial fuel cell (MFC) technology has the potential to become a major renewable energy resource by degrading organic pollutants in wastewater. The performance of MFC directly depends on the kinetics of the electrode reactions within the fuel cell, with the performance of the electrodes heavily influenced by the materials they are made from. A wide range of materials have been tested to improve the performance of MFCs. In the past decade, carbon-based nanomaterials have emerged as promising materials for both anode and cathode construction. Composite materials have also shown to have the potential to become materials of choice for electrode manufacture. Various transition metal oxides have been investigated as alternatives to conventional expensive metals like platinum for oxygen reduction reaction. In this review, different carbon-based nanomaterials and composite materials are discussed for their potential use as MFC electrodes.

Fuel Cell Vehicle Basics | NREL

Science.gov (United States)

Fuel Cell Vehicle Basics Fuel Cell Vehicle Basics Researchers are developing fuel cells that can be silver four-door sedan being driven on a roadway and containing the words "hydrogen fuel cell electric" across the front and rear doors. This prototype hydrogen fuel cell electric vehicle was

Design of flexible polyphenylene proton-conducting membrane for next-generation fuel cells.

Science.gov (United States)

Miyake, Junpei; Taki, Ryunosuke; Mochizuki, Takashi; Shimizu, Ryo; Akiyama, Ryo; Uchida, Makoto; Miyatake, Kenji

2017-10-01

Proton exchange membrane fuel cells (PEMFCs) are promising devices for clean power generation in automotive, stationary, and portable applications. Perfluorosulfonic acid (PFSA) ionomers (for example, Nafion) have been the benchmark PEMs; however, several problems, including high gas permeability, low thermal stability, high production cost, and environmental incompatibility, limit the widespread dissemination of PEMFCs. It is believed that fluorine-free PEMs can potentially address all of these issues; however, none of these membranes have simultaneously met the criteria for both high performance (for example, proton conductivity) and durability (for example, mechanical and chemical stability). We present a polyphenylene-based PEM (SPP-QP) that fulfills the required properties for fuel cell applications. The newly designed PEM exhibits very high proton conductivity, excellent membrane flexibility, low gas permeability, and extremely high stability, with negligible degradation even under accelerated degradation conditions, which has never been achieved with existing fluorine-free PEMs. The polyphenylene PEM also exhibits reasonably high fuel cell performance, with excellent durability under practical conditions. This new PEM extends the limits of existing fluorine-free proton-conductive materials and will help to realize the next generation of PEMFCs via cost reduction as well as the performance improvement compared to the present PFSA-based PEMFC systems.

Fuel Cell Power Plants Renewable and Waste Fuels

Science.gov (United States)

2011-01-13

logo, Direct FuelCell and “DFC” are all registered trademarks (®) of FuelCell Energy, Inc. Applications •On-site self generation of combined heat... of FuelCell Energy, Inc. Fuels Resources for DFC • Natural Gas and LNG • Propane • Biogas (by Anaerobicnaerobic Digestion) - Municipal Waste...FUEL RESOURCES z NATURAL GAS z PROPANE z DFC H2 (50-60%) z ETHANOL zWASTE METHANE z BIOGAS z COAL GAS Diversity of Fuels plus High Efficiency

Transport phenomena in fuel cells : from microscale to macroscale

Energy Technology Data Exchange (ETDEWEB)

Djilali, N. [Victoria Univ., BC (Canada). Dept. of Mechanical Engineering]|[Victoria Univ., BC (Canada). Inst. for Integrated Energy Systems

2006-07-01

Proton Exchange Membrane (PEM) fuel cells rely on an array of thermofluid transport processes for the regulated supply of reactant gases and the removal of by-product heat and water. Flows are characterized by a broad range of length and time scales that take place in conjunction with reaction kinetics in a variety of regimes and structures. This paper examined some of the challenges related to computational fluid dynamics (CFD) modelling of PEM fuel cell transport phenomena. An overview of the main features, components and operation of PEM fuel cells was followed by a discussion of the various strategies used for component modelling of the electrolyte membrane; the gas diffusion layer; microporous layer; and flow channels. A review of integrated CFD models for PEM fuel cells included the coupling of electrochemical thermal and fluid transport with 3-D unit cell simulations; air-breathing micro-structured fuel cells; and stack level modelling. Physical models for modelling of transport at the micro-scale were also discussed. Results of the review indicated that the treatment of electrochemical reactions in a PEM fuel cell currently combines classical reaction kinetics with solutions procedures to resolve charged species transport, which may lead to thermodynamically inconsistent solutions for more complex systems. Proper representation of the surface coverage of all the chemical species at all reaction sites is needed, and secondary reactions such as platinum (Pt) dissolution and oxidation must be accounted for in order to model and understand degradation mechanisms in fuel cells. While progress has been made in CFD-based modelling of fuel cells, functional and predictive capabilities remain a challenge because of fundamental modelling and material characterization deficiencies in ionic and water transport in polymer membranes; 2-phase transport in porous gas diffusion electrodes and gas flow channels; inadequate macroscopic modelling and resolution of catalyst

Metallofullerenes as fuel cell electrocatalysts: a theoretical investigation of adsorbates on C59Pt.

Science.gov (United States)

Gabriel, Margaret A; Genovese, Luigi; Krosnicki, Guillaume; Lemaire, Olivier; Deutsch, Thierry; Franco, Alejandro A

2010-08-28

Nano-structured electrode degradation in state-of-the-art polymer electrolyte membrane fuel cells (PEMFCs) is one of the main shortcomings that limit the large-scale development and commercialization of this technology. During normal operating conditions of the fuel cell, the PEMFC lifetime tends to be limited by coarsening of the cathode's Pt-based catalyst and by corrosion of the cathode's carbon black support. Because of their chemical properties, metallofullerenes such as C(59)Pt may be more electrochemically stable than the Pt/C mixture. In this paper we investigate, by theoretical methods, the stability of oxygen reduction reaction (ORR) adsorbates on the metallofullerene C(59)Pt and evaluate its potential as a PEMFC fuel cell catalyst.

Fuel cells - a perspective

International Nuclear Information System (INIS)

Biegler, T.

2005-01-01

Unfortunately, fuel cell publicity conveys expectations and hopes that are often based on uncritical interpretations of the underlying science. The aim here is to use that science to analyse how the technology has developed and what can realistically be delivered by fuel cells. There have been great achievements in fuel cell technology over the past decade, with most types reaching an advanced stage of engineering development. But there has been some muddled thinking about one critical aspect, fuel cell energy efficiency. The 'Carnot cycle' argument, that fuel cells must be much more efficient than heat engines, is a red herring, of no help in predicting real efficiencies. In practice, fuel cells are not always particularly efficient and there are good scientific reasons for this. Cost reduction is a big issue for fuel cells. They are not in principle especially simple devices. Better engineering and mass production will presumably bring costs down, but because of their inherent complexity there is no reason to expect them to be cheap. It is fair to conclude that predictions of fuel cells as commonplace components of energy systems (including a hydrogen economy) need to be treated with caution, at least until major improvements eventuate. However, one type, the direct methanol fuel cell, is aimed at a clear existing market in consumer electronics

Fuel cells

NARCIS (Netherlands)

Veen, van J.A.R.; Janssen, F.J.J.G.; Santen, van R.A.

1999-01-01

The principles and present-day embodiments of fuel cells are discussed. Nearly all cells are hydrogen/oxygen ones, where the hydrogen fuel is usually obtained on-site from the reforming of methane or methanol. There exists a tension between the promise of high efficiency in the conversion of

Fuel cell cassette with compliant seal

Science.gov (United States)

Karl, Haltiner, Jr. J.; Anthony, Derose J.; Klotzbach, Darasack C.; Schneider, Jonathan R.

2017-11-07

A fuel cell cassette for forming a fuel cell stack along a fuel cell axis includes a cell retainer, a plate positioned axially to the cell retainer and defining a space axially with the cell retainer, and a fuel cell having an anode layer and a cathode layer separated by an electrolyte layer. The outer perimeter of the fuel cell is positioned in the space between the plate and the cell retainer, thereby retaining the fuel cell and defining a cavity between the cell retainer, the fuel cell, and the plate. The fuel cell cassette also includes a seal disposed within the cavity for sealing the edge of the fuel cell. The seal is compliant at operational temperatures of the fuel cell, thereby allowing lateral expansion and contraction of the fuel cell within the cavity while maintaining sealing at the edge of the fuel cell.

Thermoeconomic analysis of a fuel cell hybrid power system from the fuel cell experimental data

Energy Technology Data Exchange (ETDEWEB)

Alvarez, Tomas [Endesa Generacion, Ribera del Loira, 60, 28042 Madrid (Spain)]. E-mail: talvarez@endesa.es; Valero, Antonio [Fundacion CIRCE, Centro Politecnico Superior, Maria de Luna, 3, 50018 Zaragoza (Spain); Montes, Jose M. [ETSIMM-Universidad Politecnica de.Madrid, Rios Rosas, 21, 28003 Madrid (Spain)

2006-08-15

An innovative configuration of fuel cell technology is proposed based on a hybrid fuel cell system that integrates a turbogenerator to overcome the intrinsic limitations of fuel cells in conventional operation. An analysis is done of the application of molten carbonate fuel cell technology at the Guadalix Fuel Cell Test Facility, for the assessment of the performance of the fuel cell prototype to be integrated in the Hybrid Fuel Cell System. This is completed with a thermoeconomic analysis of the 100 kW cogeneration fuel cell power plant which was subsequently built. The operational results and design limitations are evaluated, together with the operational limits and thermodynamic inefficiencies (exergy destruction and losses) of the 100 kW fuel cell. This leads to the design of a hybrid system in order to demonstrate the possibilities and benefits of the new hybrid configuration. The results are quantified through a thermoeconomic analysis in order to get the most cost-effective plant configuration. One promising configuration is the MCFC topper where the fuel cell in the power plant behaves as a combustor for the turbogenerator. The latter behaves as the balance of plant for the fuel cell. The combined efficiency increased to 57% and NOx emissions are essentially eliminated. The synergy of the fuel cell/turbine hybrids lies mainly in the use of the rejected thermal energy and residual fuel from the fuel cell to drive the turbogenerator in a 500 kW hybrid system.

Fuel cell systems

International Nuclear Information System (INIS)

Kotevski, Darko

2003-01-01

Fuel cell systems are an entirely different approach to the production of electricity than traditional technologies. They are similar to the batteries in that both produce direct current through electrochemical process. There are six types of fuel cells each with a different type of electrolyte, but they all share certain important characteristics: high electrical efficiency, low environmental impact and fuel flexibility. Fuel cells serve a variety of applications: stationary power plants, transport vehicles and portable power. That is why world wide efforts are addressed to improvement of this technology. (Original)

Proton exchange membrane fuel cells

CERN Document Server

Qi, Zhigang

2013-01-01

Preface Proton Exchange Membrane Fuel CellsFuel CellsTypes of Fuel CellsAdvantages of Fuel CellsProton Exchange Membrane Fuel CellsMembraneCatalystCatalyst LayerGas Diffusion MediumMicroporous LayerMembrane Electrode AssemblyPlateSingle CellStackSystemCell Voltage Monitoring Module (CVM)Fuel Supply Module (FSM)Air Supply Module (ASM)Exhaust Management Module (EMM)Heat Management Module (HMM)Water Management Module (WMM)Internal Power Supply Module (IPM)Power Conditioning Module (PCM)Communications Module (COM)Controls Module (CM)SummaryThermodynamics and KineticsTheoretical EfficiencyVoltagePo

Application of fault tree analysis to fuel cell diagnosis

Energy Technology Data Exchange (ETDEWEB)

Yousfi Steiner, N.; Mocoteguy, P. [European Institute for Energy Research (EIFER), Karlsruhe (Germany); Hissel, D. [FEMTO-ST/ENISYS/FC LAB, UMR CNRS 6174, University of Franche-Comte, Belfort (France); Candusso, D. [IFSTTAR/FC LAB, Institute of Science and Technology for Transport, Development and Networks, Belfort (France); Marra, D.; Pianese, C.; Sorrentino, M. [Department of Industrial Engineering, University of Salerno, Fisciano (Italy)

2012-04-15

Reliability and lifetime are common issues for the development and commercialization of fuel cells technologies'. As a consequence, their improvement is a major challenge and the last decade has experienced a growing interest in activities that aims at understanding the degradation mechanisms and at developing fuel cell systems diagnosis tools. Fault Tree Analysis (FTA) is one of the deductive tools that allow ''linking'' an undesired state to a combination of lower-level events via a ''top-down'' approach which is mainly used in safety and reliability engineering. The objective of this paper is to give an overview of the use and the contribution of FTA to both SOFC and PEFC diagnosis. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Fuel cells for commercial energy

Science.gov (United States)

Huppmann, Gerhard; Weisse, Eckart; Bischoff, Manfred

1990-04-01

The development of various types of fuel cells is described. Advantges and drawbacks are considered for alkaline fuel cells, phosphoric acid fuel cells, and molten carbonate fuel cells. It is shown that their modular construction is particularly adapted to power heat systems. A comparison which is largely in favor of fuel cells, is made between coal, oil, natural gas power stations, and fuel cells. Safety risks in operation are also compared with those of conventional power stations. Fuel cells are particularly suited for dwellings, shopping centers, swimming pools, other sporting installations, and research facilities, whose high current and heat requirements can be covered by power heat coupling.

Solid oxide fuel cell performance comparison fuelled by methane, MeOH, EtOH and diesel surrogate C8H18

DEFF Research Database (Denmark)

Liso, Vincenzo; Cinti, Giovanni; Nielsen, Mads Pagh

2016-01-01

Carbon deposition is a major cause of degradation in solid oxide fuel cell systems. The ability to predict carbon formation in reforming processes is thus absolutely necessary for stable operation of solid oxide fuel cell systems. In the open literature it is found that thesteam input is always c...

Fuel cell sub-assembly

Science.gov (United States)

Chi, Chang V.

1983-01-01

A fuel cell sub-assembly comprising a plurality of fuel cells, a first section of a cooling means disposed at an end of the assembly and means for connecting the fuel cells and first section together to form a unitary structure.

Effect of humic acids on electricity generation integrated with xylose degradation in microbial fuel cells

DEFF Research Database (Denmark)

Huang, Liping; Angelidaki, Irini

2008-01-01

Pentose and humic acids (HA) are the main components of hydrolysates, the liquid fraction produced during thermohydrolysis of lignocellulosic material. Electricity generation integrated with xylose (typical pentose) degradation as well as the effect of HA on electricity production in microbial fuel...... to controls where HAs were not added, addition of commercial HA resulted in increase of power density and coulombic efficiency, which ranged from 7.5% to 67.4% and 24% to 92.6%, respectively. Digested manure wastewater (DMW) was tested as potential mediator for power generation due to its content of natural...

Fuel cell hardware-in-loop

Energy Technology Data Exchange (ETDEWEB)

Moore, R.M.; Randolf, G.; Virji, M. [University of Hawaii, Hawaii Natural Energy Institute (United States); Hauer, K.H. [Xcellvision (Germany)

2006-11-08

Hardware-in-loop (HiL) methodology is well established in the automotive industry. One typical application is the development and validation of control algorithms for drive systems by simulating the vehicle plus the vehicle environment in combination with specific control hardware as the HiL component. This paper introduces the use of a fuel cell HiL methodology for fuel cell and fuel cell system design and evaluation-where the fuel cell (or stack) is the unique HiL component that requires evaluation and development within the context of a fuel cell system designed for a specific application (e.g., a fuel cell vehicle) in a typical use pattern (e.g., a standard drive cycle). Initial experimental results are presented for the example of a fuel cell within a fuel cell vehicle simulation under a dynamic drive cycle. (author)

Seventh Edition Fuel Cell Handbook

Energy Technology Data Exchange (ETDEWEB)

NETL

2004-11-01

Provides an overview of fuel cell technology and research projects. Discusses the basic workings of fuel cells and their system components, main fuel cell types, their characteristics, and their development status, as well as a discussion of potential fuel cell applications.

Materials for fuel cells

OpenAIRE

Haile, Sossina M

2003-01-01

Because of their potential to reduce the environmental impact and geopolitical consequences of the use of fossil fuels, fuel cells have emerged as tantalizing alternatives to combustion engines. Like a combustion engine, a fuel cell uses some sort of chemical fuel as its energy source but, like a battery, the chemical energy is directly converted to electrical energy, without an often messy and relatively inefficient combustion step. In addition to high efficiency and low emissions, fuel cell...

Limitations of Commercializing Fuel Cell Technologies

Science.gov (United States)

Nordin, Normayati

2010-06-01

Fuel cell is the technology that, nowadays, is deemed having a great potential to be used in supplying energy. Basically, fuel cells can be categorized particularly by the kind of employed electrolyte. Several fuel cells types which are currently identified having huge potential to be utilized, namely, Solid Oxide Fuel Cells (SOFC), Molten Carbonate Fuel Cells (MCFC), Alkaline Fuel Cells (AFC), Phosphoric Acid Fuel Cells (PAFC), Polymer Electron Membrane Fuel Cell (PEMFC), Direct Methanol Fuel Cells (DMFC) and Regenerative Fuel Cells (RFC). In general, each of these fuel cells types has their own characteristics and specifications which assign the capability and suitability of them to be utilized for any particular applications. Stationary power generations and transport applications are the two most significant applications currently aimed for the fuel cell market. It is generally accepted that there are lots of advantages if fuel cells can be excessively commercialized primarily in context of environmental concerns and energy security. Nevertheless, this is a demanding task to be accomplished, as there is some gap in fuel cells technology itself which needs a major enhancement. It can be concluded, from the previous study, cost, durability and performance are identified as the main limitations to be firstly overcome in enabling fuel cells technology become viable for the market.

Bioelectricity generation from coconut husk retting wastewater in fed batch operating microbial fuel cell by phenol degrading microorganism

International Nuclear Information System (INIS)

Jayashree, C.; Arulazhagan, P.; Adish Kumar, S.; Kaliappan, S.; Yeom, Ick Tae; Rajesh Banu, J.

2014-01-01

Dual chamber microbial fuel cell (MFC) operated at fed batch mode for the treatment of retting wastewater has potently achieved both current generation and phenol removal. Hydraulic retention time (HRT) of the reactor was varied from 40 days to 10 days. COD (chemical oxygen demand) removal was 91% at 40 days HRT, with an initial COD concentration of 530 ± 50 g m −3 . Retting wastewater with an initial phenol concentration of 320 ± 60 g m −3 procured a highest phenol removal of 93% at 40 days HRT of the microbial fuel cell. Maximum power density of 362 mW m −2 was achieved using retting wastewater at HRT of 20 days with an internal resistance of 150 Ω in a dual chambered MFC. The bacterial strains in anode region, reported to be responsible for potential phenol removal, were identified as Ochrobactrum sp. RA1 (KJ408266), Ochrobactrum sp. RA2 (KJ408267) and Pesudomonas aeruginosa RA3 (KJ408268) using phylogenetic analysis. The study reveals that, dual chambered MFC effectively removed the phenol from retting wastewater along with power generation. - Highlights: • Maximum power density of 362 mW m −2 (150 Ω) was achieved at HRT of 20 days. • 91% COD removal and 93% phenol removal was observed at HRT of 40 days. • 25% coulombic efficiency was achieved in treatment of retting wastewater with MFC. • Phylogenetic analysis detect phenol degrading Ochrobactrum sp.RA1 in anode biofilm. • In addition, Ochrobactrum sp.RA2 and Pseudomonas aeruginosa RA3 were also isolated

Direct Methanol Fuel Cell, DMFC

Directory of Open Access Journals (Sweden)

Amornpitoksuk, P.

2003-09-01

Full Text Available Direct Methanol Fuel Cell, DMFC is a kind of fuel cell using methanol as a fuel for electric producing. Methanol is low cost chemical substance and it is less harmful than that of hydrogen fuel. From these reasons it can be commercial product. The electrocatalytic reaction of methanol fuel uses Pt-Ru metals as the most efficient catalyst. In addition, the property of membrane and system designation are also effect to the fuel cell efficient. Because of low power of methanol fuel cell therefore, direct methanol fuel cell is proper to use for the energy source of small electrical devices and vehicles etc.

Fuel cell with internal flow control

Science.gov (United States)

Haltiner, Jr., Karl J.; Venkiteswaran, Arun [Karnataka, IN

2012-06-12

A fuel cell stack is provided with a plurality of fuel cell cassettes where each fuel cell cassette has a fuel cell with an anode and cathode. The fuel cell stack includes an anode supply chimney for supplying fuel to the anode of each fuel cell cassette, an anode return chimney for removing anode exhaust from the anode of each fuel cell cassette, a cathode supply chimney for supplying oxidant to the cathode of each fuel cell cassette, and a cathode return chimney for removing cathode exhaust from the cathode of each fuel cell cassette. A first fuel cell cassette includes a flow control member disposed between the anode supply chimney and the anode return chimney or between the cathode supply chimney and the cathode return chimney such that the flow control member provides a flow restriction different from at least one other fuel cell cassettes.

Metal membrane-type 25-kW methanol fuel processor for fuel-cell hybrid vehicle

Science.gov (United States)

Han, Jaesung; Lee, Seok-Min; Chang, Hyuksang

A 25-kW on-board methanol fuel processor has been developed. It consists of a methanol steam reformer, which converts methanol to hydrogen-rich gas mixture, and two metal membrane modules, which clean-up the gas mixture to high-purity hydrogen. It produces hydrogen at rates up to 25 N m 3/h and the purity of the product hydrogen is over 99.9995% with a CO content of less than 1 ppm. In this fuel processor, the operating condition of the reformer and the metal membrane modules is nearly the same, so that operation is simple and the overall system construction is compact by eliminating the extensive temperature control of the intermediate gas streams. The recovery of hydrogen in the metal membrane units is maintained at 70-75% by the control of the pressure in the system, and the remaining 25-30% hydrogen is recycled to a catalytic combustion zone to supply heat for the methanol steam-reforming reaction. The thermal efficiency of the fuel processor is about 75% and the inlet air pressure is as low as 4 psi. The fuel processor is currently being integrated with 25-kW polymer electrolyte membrane fuel-cell (PEMFC) stack developed by the Hyundai Motor Company. The stack exhibits the same performance as those with pure hydrogen, which proves that the maximum power output as well as the minimum stack degradation is possible with this fuel processor. This fuel-cell 'engine' is to be installed in a hybrid passenger vehicle for road testing.

Fuel cells:

DEFF Research Database (Denmark)

Sørensen, Bent

2013-01-01

A brief overview of the progress in fuel cell applications and basic technology development is presented, as a backdrop for discussing readiness for penetration into the marketplace as a solution to problems of depletion, safety, climate or environmental impact from currently used fossil and nucl......A brief overview of the progress in fuel cell applications and basic technology development is presented, as a backdrop for discussing readiness for penetration into the marketplace as a solution to problems of depletion, safety, climate or environmental impact from currently used fossil...... and nuclear fuel-based energy technologies....

Materials for low-temperature fuel cells

CERN Document Server

Ladewig, Bradley; Yan, Yushan; Lu, Max

2014-01-01

There are a large number of books available on fuel cells; however, the majority are on specific types of fuel cells such as solid oxide fuel cells, proton exchange membrane fuel cells, or on specific technical aspects of fuel cells, e.g., the system or stack engineering. Thus, there is a need for a book focused on materials requirements in fuel cells. Key Materials in Low-Temperature Fuel Cells is a concise source of the most important and key materials and catalysts in low-temperature fuel cells. A related book will cover key materials in high-temperature fuel cells. The two books form part

Materials for high-temperature fuel cells

CERN Document Server

Jiang, San Ping; Lu, Max

2013-01-01

There are a large number of books available on fuel cells; however, the majority are on specific types of fuel cells such as solid oxide fuel cells, proton exchange membrane fuel cells, or on specific technical aspects of fuel cells, e.g., the system or stack engineering. Thus, there is a need for a book focused on materials requirements in fuel cells. Key Materials in High-Temperature Fuel Cells is a concise source of the most important and key materials and catalysts in high-temperature fuel cells with emphasis on the most important solid oxide fuel cells. A related book will cover key mater

The synthesis of carbon nanocomposites as fuel cell catalyst support and the characterization of fuel cell catalysts by spatially resolved scanning mass spectrometry

Energy Technology Data Exchange (ETDEWEB)

Li, Nan

2007-07-01

Ammonia decomposition over Ni/SiO{sub 2} and Ni/MgO was investigated by temperature-programmed desorption (TPD) and temperature-programmed surface reaction (TPSR) in order to produce CO{sub x} free hydrogen fuel for fuel cell application. A highly efficient route for the synthesis of carbon nanocomposites based on electrochemical deposition and iron catalyzed chemical vapor deposition (CVD) was developed in order to obtain a promising substrate for fuel cell catalysts. The duration of electrochemical deposition, temperature and time for the carbon nanotubes (CNTs) growth had been optimized to achieve higher surface area after the growth. Hierarchically structured CNTs composites had been synthesized and electrochemical studies provided evidence for the strong interaction among the substrate and grown CNTs, which are essential for the application in fuel cells. A straightforward strategy was developed to synthesize well dispersed gold nanoparticles with a diameter of 4 to 6 nm on the sidewall of multi-walled carbon nanotubes (MWNTs). A gas flow set-up was developed for the evaluation of fuel cell catalysts by performing scanning mass spectrometry with integrated constant-distance positioning. Methanol oxidation was identified as a suitable test reaction. The diameter of scanning probe was reduced in order to achieve higher spatial resolution. Spatially resolved scanning mass spectrometry was successfully applied to visualize the catalytic activity over Pt-based catalysts and monitor the local activity of a catalysts coated membrane (CCM). The gas-solid phase reaction results were proved to be accurate, reliable and independent of the sample topography. This analytical method opens the way for fast quality control of the catalyst coating with respect to even coating and absence of damages, and for a better understanding of the CCM degradation in polymer membrane electrolyte fuel cells (PEMFCs). (orig.)

HTPEM Fuel Cell Impedance

DEFF Research Database (Denmark)

Vang, Jakob Rabjerg

As part of the process to create a fossil free Denmark by 2050, there is a need for the development of new energy technologies with higher efficiencies than the current technologies. Fuel cells, that can generate electricity at higher efficiencies than conventional combustion engines, can...... potentially play an important role in the energy system of the future. One of the fuel cell technologies, that receives much attention from the Danish scientific community is high temperature proton exchange membrane (HTPEM) fuel cells based on polybenzimidazole (PBI) with phosphoric acid as proton conductor....... This type of fuel cell operates at higher temperature than comparable fuel cell types and they distinguish themselves by high CO tolerance. Platinum based catalysts have their efficiency reduced by CO and the effect is more pronounced at low temperature. This Ph.D. Thesis investigates this type of fuel...

Experimental analysis of a PEM fuel cell 15 W; Analise experimental de uma celula a combustivel PEM 15W

Energy Technology Data Exchange (ETDEWEB)

Miyake, Raphael Guardini; Bazzo, Edson [Universidade Federal de Santa Catarina (UFSC), Florianopolis, SC (Brazil). Dept. de Engenharia Mecanica. Lab. de Combustao e Engenharia de Sistemas Termicos], e-mail: miyake@labcet.ufsc.br, e-mail: ebazzo@emc.ufsc.br

2006-07-01

Fuel cells have been considered a promising alternative for electric energy generation. In order to contribute with the development of this technology, a PEM fuel cell was installed and new experiments were carried out at LabCET (Laboratory of Combustion and Thermal System Engineering). Previous results have shown polarization curves identifying the need of rigorous controlling of humidification temperature of the fuel cell. In this paper, new results were carried out considering the use of a fan connected to the fuel cell and possible degradation in the electrolyte, after a relative long time operation. New polarization curves were plotted for comparison with previous results. (author)

Study on component interface evolution of a solid oxide fuel cell stack after long term operation

Science.gov (United States)

Yang, Jiajun; Huang, Wei; Wang, Xiaochun; Li, Jun; Yan, Dong; Pu, Jian; Chi, Bo; Li, Jian

2018-05-01

A 5-cell solid oxide fuel cell (SOFC) stack with external manifold structure is assembled and underwent a durability test with an output of 250 W for nearly 4400 h when current density and operating temperature are 355 mA/cm2 and 750 °C. Cells used in the stack are anode-supported cells (ASC) with yttria-stabilized zirconia (YSZ) electrolytes, Ni/YSZ hydrogen electrodes, and YSZ based composite cathode. The dimension of the cell is 150 × 150 mm (active area: 130 × 130 mm). Ceramic-glass sealant is used in the stack to keep the gas tightness between cells, interconnects and manifolds. Pure hydrogen and dry air are used as fuel and oxidant respectively. The stack has a maximum output of 340 W at 562 mA/cm2 current density at 750 °C. The stack shows a degradation of 1.5% per 1000 h during the test with 2 thermal cycles to room temperature. After the test, the stack was dissembled and examined. The relationship between microstructure changes of interfaces and degradation in the stack are discussed. The microstructure evolution of interfaces between electrode, contact material and current collector are unveiled and their relationship with the degradation is discussed.

Electric terminal performance and characterization of solid oxide fuel cells and systems

Science.gov (United States)

Lindahl, Peter Allan

Solid Oxide Fuel Cells (SOFCs) are electrochemical devices which can effect efficient, clean, and quiet conversion of chemical to electrical energy. In contrast to conventional electricity generation systems which feature multiple discrete energy conversion processes, SOFCs are direct energy conversion devices. That is, they feature a fully integrated chemical to electrical energy conversion process where the electric load demanded of the cell intrinsically drives the electrochemical reactions and associated processes internal to the cell. As a result, the cell's electric terminals provide a path for interaction between load side electric demand and the conversion side processes. The implication of this is twofold. First, the magnitude and dynamic characteristics of the electric load demanded of the cell can directly impact the long-term efficacy of the cell's chemical to electrical energy conversion. Second, the electric terminal response to dynamic loads can be exploited for monitoring the cell's conversion side processes and used in diagnostic analysis and degradation-mitigating control schemes. This dissertation presents a multi-tier investigation into this electric terminal based performance characterization of SOFCs through the development of novel test systems, analysis techniques and control schemes. First, a reference-based simulation system is introduced. This system scales up the electric terminal performance of a prototype SOFC system, e.g. a single fuel cell, to that of a full power-level stack. This allows realistic stack/load interaction studies while maintaining explicit ability for post-test analysis of the prototype system. Next, a time-domain least squares fitting method for electrochemical impedance spectroscopy (EIS) is developed for reduced-time monitoring of the electrochemical and physicochemical mechanics of the fuel cell through its electric terminals. The utility of the reference-based simulator and the EIS technique are demonstrated

Direct hydrocarbon fuel cells

Science.gov (United States)

Barnett, Scott A.; Lai, Tammy; Liu, Jiang

2010-05-04

The direct electrochemical oxidation of hydrocarbons in solid oxide fuel cells, to generate greater power densities at lower temperatures without carbon deposition. The performance obtained is comparable to that of fuel cells used for hydrogen, and is achieved by using novel anode composites at low operating temperatures. Such solid oxide fuel cells, regardless of fuel source or operation, can be configured advantageously using the structural geometries of this invention.

Aircraft Fuel Cell Power Systems

Science.gov (United States)

Needham, Robert

2004-01-01

In recent years, fuel cells have been explored for use in aircraft. While the weight and size of fuel cells allows only the smallest of aircraft to use fuel cells for their primary engines, fuel cells have showed promise for use as auxiliary power units (APUs), which power aircraft accessories and serve as an electrical backup in case of an engine failure. Fuel cell MUS are both more efficient and emit fewer pollutants. However, sea-level fuel cells need modifications to be properly used in aircraft applications. At high altitudes, the ambient air has a much lower pressure than at sea level, which makes it much more difficult to get air into the fuel cell to react and produce electricity. Compressors can be used to pressurize the air, but this leads to added weight, volume, and power usage, all of which are undesirable things. Another problem is that fuel cells require hydrogen to create electricity, and ever since the Hindenburg burst into flames, aircraft carrying large quantities of hydrogen have not been in high demand. However, jet fuel is a hydrocarbon, so it is possible to reform it into hydrogen. Since jet fuel is already used to power conventional APUs, it is very convenient to use this to generate the hydrogen for fuel-cell-based APUs. Fuel cells also tend to get large and heavy when used for applications that require a large amount of power. Reducing the size and weight becomes especially beneficial when it comes to fuel cells for aircraft. My goal this summer is to work on several aspects of Aircraft Fuel Cell Power System project. My first goal is to perform checks on a newly built injector rig designed to test different catalysts to determine the best setup for reforming Jet-A fuel into hydrogen. These checks include testing various thermocouples, transmitters, and transducers, as well making sure that the rig was actually built to the design specifications. These checks will help to ensure that the rig will operate properly and give correct results

Commercialization of fuel-cells

Energy Technology Data Exchange (ETDEWEB)

Penner, S.S.; Appleby, A.J.; Baker, B.S.; Bates, J.L.; Buss, L.B.; Dollard, W.J.; Farris, P.J.; Gillis, E.A.; Gunsher, J.A.; Khandkar, A.; Krumpelt, M.; O' Sullivan, J.B.; Runte, G.; Savinell, R.F.; Selman, J.R.; Shores, D.A.; Tarman, P.

1995-03-01

This report is an abbreviated version of the ''Report of the DOE Advanced Fuel Cell Commercialization Working Group (AFC2WG),'' released January 1995. We describe fuel-cell commercialization for stationary power applications of phosphoric acid, molten carbonate, solid oxide, and polymer electrolyte membrane fuel cells.

Isolation and Characterization of Phenanthrene Degrading Bacteria from Diesel Fuel-Contaminated Antarctic Soils

Directory of Open Access Journals (Sweden)

Alejandro Gran-Scheuch

2017-08-01

Full Text Available Antarctica is an attractive target for human exploration and scientific investigation, however the negative effects of human activity on this continent are long lasting and can have serious consequences on the native ecosystem. Various areas of Antarctica have been contaminated with diesel fuel, which contains harmful compounds such as heavy metals and polycyclic aromatic hydrocarbons (PAH. Bioremediation of PAHs by the activity of microorganisms is an ecological, economical, and safe decontamination approach. Since the introduction of foreign organisms into the Antarctica is prohibited, it is key to discover native bacteria that can be used for diesel bioremediation. By following the degradation of the PAH phenanthrene, we isolated 53 PAH metabolizing bacteria from diesel contaminated Antarctic soil samples, with three of these isolates exhibiting a high phenanthrene degrading capacity. In particular, the Sphingobium xenophagum D43FB isolate showed the highest phenanthrene degradation ability, generating up to 95% degradation of initial phenanthrene. D43FB can also degrade phenanthrene in the presence of its usual co-pollutant, the heavy metal cadmium, and showed the ability to grow using diesel-fuel as a sole carbon source. Microtiter plate assays and SEM analysis revealed that S. xenophagum D43FB exhibits the ability to form biofilms and can directly adhere to phenanthrene crystals. Genome sequencing analysis also revealed the presence of several genes involved in PAH degradation and heavy metal resistance in the D43FB genome. Altogether, these results demonstrate that S. xenophagum D43FB shows promising potential for its application in the bioremediation of diesel fuel contaminated-Antarctic ecosystems.

Fuel cells for naval aviation

International Nuclear Information System (INIS)

Satzberg, S.; Field, S.; Abu-Ali, M.

2003-01-01

Recent advances in fuel cell technology have occurred which make fuel cells increasingly attractive for electric power generation on future naval and commercial aircraft applications. These advances include significant increases in power density, the development of compact fuel reformers, and cost reductions due to commercialization efforts. The Navy's interest in aircraft fuel cells stems from their high energy efficiency (up to 40-60% for simple cycle; 60-70% for combined gas turbine/fuel cell hybrid cycles), and their negligible NOx and hydrocarbon emissions compared to conventional generators. While the U.S. Navy has been involved with fuel cell research and development as early as the 1960s, many of the early programs were for special warfare or undersea applications. In 1997, the Office of Naval Research (ONR) and Naval Sea Systems Command (NAVSEA) initiated a program to marinize commercial fuel cell technology for future Navy shipboard applications. The power density of fuel cell power systems is approaching the levels necessary for serious consideration for aircraft suitability. ONR and Naval Air Systems Command (NAVAIR) are initiating a program to develop a fuel cell power system suitable for future Navy aircraft applications, utilizing as much commercially-available technology as possible. (author)

Fuel Cell Powered Lift Truck

Energy Technology Data Exchange (ETDEWEB)

Moulden, Steve [Sysco Food Service, Houston, TX (United States)

2015-08-20

This project, entitled “Recovery Act: Fuel Cell-Powered Lift Truck Sysco (Houston) Fleet Deployment”, was in response to DOE funding opportunity announcement DE-PS36-08GO98009, Topic 7B, which promotes the deployment of fuel cell powered material handling equipment in large, multi-shift distribution centers. This project promoted large-volume commercialdeployments and helped to create a market pull for material handling equipment (MHE) powered fuel cell systems. Specific outcomes and benefits involved the proliferation of fuel cell systems in 5-to 20-kW lift trucks at a high-profile, real-world site that demonstrated the benefits of fuel cell technology and served as a focal point for other nascent customers. The project allowed for the creation of expertise in providing service and support for MHE fuel cell powered systems, growth of existing product manufacturing expertise, and promoted existing fuel cell system and component companies. The project also stimulated other MHE fleet conversions helping to speed the adoption of fuel cell systems and hydrogen fueling technology. This document also contains the lessons learned during the project in order to communicate the successes and difficulties experienced, which could potentially assist others planning similar projects.

2008 Fuel Cell Technologies Market Report

Energy Technology Data Exchange (ETDEWEB)

DOE

2010-06-01

Fuel cells are electrochemical devices that combine hydrogen and oxygen to produce electricity, water, and heat. Unlike batteries, fuel cells continuously generate electricity, as long as a source of fuel is supplied. Moreover, fuel cells do not burn fuel, making the process quiet, pollution-free and two to three times more efficient than combustion. Fuel cell systems can be a truly zero-emission source of electricity, if the hydrogen is produced from non-polluting sources. Global concerns about climate change, energy security, and air pollution are driving demand for fuel cell technology. More than 630 companies and laboratories in the United States are investing $1 billion a year in fuel cells or fuel cell component technologies. This report provides an overview of trends in the fuel cell industry and markets, including product shipments, market development, and corporate performance. It also provides snapshots of select fuel cell companies, including general business strategy and market focus, as well as, financial information for select publicly-traded companies.

2008 Fuel Cell Technologies Market Report

Energy Technology Data Exchange (ETDEWEB)

Vincent, B. [Breakthrough Technologies Inst., Washington, DC (United States)

2010-06-30

Fuel cells are electrochemical devices that combine hydrogen and oxygen to produce electricity, water, and heat. Unlike batteries, fuel cells continuously generate electricity, as long as a source of fuel is supplied. Moreover, fuel cells do not burn fuel, making the process quiet, pollution-free and two to three times more efficient than combustion. Fuel cell systems can be a truly zero-emission source of electricity, if the hydrogen is produced from non-polluting sources. Global concerns about climate change, energy security, and air pollution are driving demand for fuel cell technology. More than 630 companies and laboratories in the United States are investing $1 billion a year in fuel cells or fuel cell component technologies. This report provides an overview of trends in the fuel cell industry and markets, including product shipments, market development, and corporate performance. It also provides snapshots of select fuel cell companies, including general business strategy and market focus, as well as, financial information for select publicly-traded companies.

Automotive Fuel Processor Development and Demonstration with Fuel Cell Systems

Energy Technology Data Exchange (ETDEWEB)

Nuvera Fuel Cells

2005-04-15

The potential for fuel cell systems to improve energy efficiency and reduce emissions over conventional power systems has generated significant interest in fuel cell technologies. While fuel cells are being investigated for use in many applications such as stationary power generation and small portable devices, transportation applications present some unique challenges for fuel cell technology. Due to their lower operating temperature and non-brittle materials, most transportation work is focusing on fuel cells using proton exchange membrane (PEM) technology. Since PEM fuel cells are fueled by hydrogen, major obstacles to their widespread use are the lack of an available hydrogen fueling infrastructure and hydrogen's relatively low energy storage density, which leads to a much lower driving range than conventional vehicles. One potential solution to the hydrogen infrastructure and storage density issues is to convert a conventional fuel such as gasoline into hydrogen onboard the vehicle using a fuel processor. Figure 2 shows that gasoline stores roughly 7 times more energy per volume than pressurized hydrogen gas at 700 bar and 4 times more than liquid hydrogen. If integrated properly, the fuel processor/fuel cell system would also be more efficient than traditional engines and would give a fuel economy benefit while hydrogen storage and distribution issues are being investigated. Widespread implementation of fuel processor/fuel cell systems requires improvements in several aspects of the technology, including size, startup time, transient response time, and cost. In addition, the ability to operate on a number of hydrocarbon fuels that are available through the existing infrastructure is a key enabler for commercializing these systems. In this program, Nuvera Fuel Cells collaborated with the Department of Energy (DOE) to develop efficient, low-emission, multi-fuel processors for transportation applications. Nuvera's focus was on (1) developing fuel

Polymer electrolyte fuel cell mini power unit for portable application

Energy Technology Data Exchange (ETDEWEB)

Urbani, F.; Squadrito, G.; Barbera, O.; Giacoppo, G.; Passalacqua, E. [CNR-ITAE, via Salita S. Lucia sopra Contesse n. 5, 98126 S. Lucia, Messina (Italy); Zerbinati, O. [Universita del Piemonte Orientale, Dip. di Scienze dell' Ambiente e della Vita, via Bellini 25/g, 15100 Alessandria (Italy)

2007-06-20

This paper describes the design, realisation and test of a power unit based on a polymer electrolyte fuel cell, operating at room temperature, for portable application. The device is composed of an home made air breathing fuel cell stack, a metal hydride tank for H{sub 2} supply, a dc-dc converter for power output control and a fan for stack cooling. The stack is composed by 10 cells with an active surface of 25 cm{sup 2} and produces a rated power of 15 W at 6 V and 2 A. The stack successfully runs with end-off fed hydrogen without appreciable performance degradation during the time. The final assembled system is able to generate 12 W at 9.5 V, and power a portable DVD player for 3 h in continuous. The power unit has collected about 100 h of operation without maintenance. (author)

Microbial fuel cell treatment of ethanol fermentation process water

Science.gov (United States)

Borole, Abhijeet P [Knoxville, TN

2012-06-05

The present invention relates to a method for removing inhibitor compounds from a cellulosic biomass-to-ethanol process which includes a pretreatment step of raw cellulosic biomass material and the production of fermentation process water after production and removal of ethanol from a fermentation step, the method comprising contacting said fermentation process water with an anode of a microbial fuel cell, said anode containing microbes thereon which oxidatively degrade one or more of said inhibitor compounds while producing electrical energy or hydrogen from said oxidative degradation, and wherein said anode is in electrical communication with a cathode, and a porous material (such as a porous or cation-permeable membrane) separates said anode and cathode.

Fuel cells: Trends in research and applications

Science.gov (United States)

Appleby, A. J.

Various aspects of fuel cells are discussed. The subjects addressed include: fuel cells for electric power production; phosphoric acid fuel cells; long-term testing of an air-cooled 2.5 kW PAFC stack in Italy; status of fuel cell research and technology in the Netherlands, Bulgaria, PRC, UK, Sweden, India, Japan, and Brazil; fuel cells from the manufacturer's viewpoint; and fuel cells using biomass-derived fuels. Also examined are: solid oxide electrolye fuel cells; aluminum-air batteries with neutral chloride electrolyte; materials research for advanced solid-state fuel cells at the Energy Research Laboratory in Denmark; molten carbonate fuel cells; the impact of the Siemens program; fuel cells at Sorapec; impact of fuel cells on the electric power generation systems in industrial and developing countries; and application of fuel cells to large vehicles.

NASA fuel cell applications for space: Endurance test results on alkaline fuel cell electrolyzer components

International Nuclear Information System (INIS)

Sheibley, D.W.

1984-01-01

Fuel cells continue to play a major role in manned spacecraft power generation. The Gemini and Apollo programs used fuel cell power plants as the primary source of mission electrical power, with batteries as the backup. The current NASA use for fuel cells is in the Orbiter program. Here, low temperature alkaline fuel cells provide all of the on-board power with no backup power source. Three power plants per shipset are utilized; the original power plant contained 32-cell substacks connected in parallel. For extended life and better power performance, each power plant now contains three 32-cell substacks connected in parallel. One of the possible future applications for fuel cells will be for the proposed manned Space Station in low earth orbit (LEO)(1, 2, 3). By integrating a water electrolysis capability with a fuel cell (a regenerative fuel cell system), a multikilowatt energy storage capability ranging from 35 kW to 250 kW can be achieved. Previous development work on fuel cell and electrolysis systems would tend to minimize the development cost of this energy storage system. Trade studies supporting initial Space Station concept development clearly show regenerative fuel cell (RFC) storage to be superior to nickel-cadmium and nickel-hydrogen batteries with regard to subsystem weight, flexibility in design, and integration with other spacecraft systems when compared for an initial station power level ranging from 60 kW to 75 kW. The possibility of scavenging residual O 2 and H 2 from the Shuttle external tank for use in fuel cells for producing power also exists

Purifier-integrated methanol reformer for fuel cell vehicles

Science.gov (United States)

Han, Jaesung; Kim, Il-soo; Choi, Keun-Sup

We developed a compact, 3-kW, purifier-integrated modular reformer which becomes the building block of full-scale 30-kW or 50-kW methanol fuel processors for fuel cell vehicles. Our proprietary technologies regarding hydrogen purification by composite metal membrane and catalytic combustion by washcoated wire-mesh catalyst were combined with the conventional methanol steam-reforming technology, resulting in higher conversion, excellent quality of product hydrogen, and better thermal efficiency than any other systems using preferential oxidation. In this system, steam reforming, hydrogen purification, and catalytic combustion all take place in a single reactor so that the whole system is compact and easy to operate. Hydrogen from the module is ultrahigh pure (99.9999% or better), hence there is no power degradation of PEMFC stack due to contamination by CO. Also, since only pure hydrogen is supplied to the anode of the PEMFC stack, 100% hydrogen utilization is possible in the stack. The module produces 2.3 Nm 3/h of hydrogen, which is equivalent to 3 kW when PEMFC has 43% efficiency. Thermal efficiency (HHV of product H 2/HHV of MeOH in) of the module is 89% and the power density of the module is 0.77 kW/l. This work was conducted in cooperation with Hyundai Motor Company in the form of a Korean national project. Currently the module is under test with an actual fuel cell stack in order to verify its performance. Sooner or later a full-scale 30-kW system will be constructed by connecting these modules in series and parallel and will serve as the fuel processor for the Korean first fuel cell hybrid vehicle.

Biological fuel cells and their applications

OpenAIRE

Shukla, AK; Suresh, P; Berchmans, S; Rajendran, A

2004-01-01

One type of genuine fuel cell that does hold promise in the long-term is the biological fuel cell. Unlike conventional fuel cells, which employ hydrogen, ethanol and methanol as fuel, biological fuel cells use organic products produced by metabolic processes or use organic electron donors utilized in the growth processes as fuels for current generation. A distinctive feature of biological fuel cells is that the electrode reactions are controlled by biocatalysts, i.e. the biological redox-reac...

Platinum supported on titanium–ruthenium oxide is a remarkably stable electrocatayst for hydrogen fuel cell vehicles

Science.gov (United States)

Parrondo, Javier; Han, Taehee; Niangar, Ellazar; Wang, Chunmei; Dale, Nilesh; Adjemian, Kev; Ramani, Vijay

2014-01-01

We report a unique and highly stable electrocatalyst—platinum (Pt) supported on titanium–ruthenium oxide (TRO)—for hydrogen fuel cell vehicles. The Pt/TRO electrocatalyst was exposed to stringent accelerated test protocols designed to induce degradation and failure mechanisms identical to those seen during extended normal operation of a fuel cell automobile—namely, support corrosion during vehicle startup and shutdown, and platinum dissolution during vehicle acceleration and deceleration. These experiments were performed both ex situ (on supports and catalysts deposited onto a glassy carbon rotating disk electrode) and in situ (in a membrane electrode assembly). The Pt/TRO was compared against a state-of-the-art benchmark catalyst—Pt supported on high surface-area carbon (Pt/HSAC). In ex situ tests, Pt/TRO lost only 18% of its initial oxygen reduction reaction mass activity and 3% of its oxygen reduction reaction-specific activity, whereas the corresponding losses for Pt/HSAC were 52% and 22%. In in situ-accelerated degradation tests performed on membrane electrode assemblies, the loss in cell voltage at 1 A · cm−2 at 100% RH was a negligible 15 mV for Pt/TRO, whereas the loss was too high to permit operation at 1 A · cm−2 for Pt/HSAC. We clearly show that electrocatalyst support corrosion induced during fuel cell startup and shutdown is a far more potent failure mode than platinum dissolution during fuel cell operation. Hence, we posit that the need for a highly stable support (such as TRO) is paramount. Finally, we demonstrate that the corrosion of carbon present in the gas diffusion layer of the fuel cell is only of minor concern. PMID:24367118

Platinum supported on titanium-ruthenium oxide is a remarkably stable electrocatayst for hydrogen fuel cell vehicles.

Science.gov (United States)

Parrondo, Javier; Han, Taehee; Niangar, Ellazar; Wang, Chunmei; Dale, Nilesh; Adjemian, Kev; Ramani, Vijay

2014-01-07

We report a unique and highly stable electrocatalyst-platinum (Pt) supported on titanium-ruthenium oxide (TRO)-for hydrogen fuel cell vehicles. The Pt/TRO electrocatalyst was exposed to stringent accelerated test protocols designed to induce degradation and failure mechanisms identical to those seen during extended normal operation of a fuel cell automobile-namely, support corrosion during vehicle startup and shutdown, and platinum dissolution during vehicle acceleration and deceleration. These experiments were performed both ex situ (on supports and catalysts deposited onto a glassy carbon rotating disk electrode) and in situ (in a membrane electrode assembly). The Pt/TRO was compared against a state-of-the-art benchmark catalyst-Pt supported on high surface-area carbon (Pt/HSAC). In ex situ tests, Pt/TRO lost only 18% of its initial oxygen reduction reaction mass activity and 3% of its oxygen reduction reaction-specific activity, whereas the corresponding losses for Pt/HSAC were 52% and 22%. In in situ-accelerated degradation tests performed on membrane electrode assemblies, the loss in cell voltage at 1 A · cm(-2) at 100% RH was a negligible 15 mV for Pt/TRO, whereas the loss was too high to permit operation at 1 A · cm(-2) for Pt/HSAC. We clearly show that electrocatalyst support corrosion induced during fuel cell startup and shutdown is a far more potent failure mode than platinum dissolution during fuel cell operation. Hence, we posit that the need for a highly stable support (such as TRO) is paramount. Finally, we demonstrate that the corrosion of carbon present in the gas diffusion layer of the fuel cell is only of minor concern.

Intact and Degraded Component Criticality Calculations of N Reactor Spent Nuclear Fuel

International Nuclear Information System (INIS)

L. Angers

2001-01-01

The objective of this calculation is to perform intact and degraded mode criticality evaluations of the Department of Energy's (DOE) N Reactor Spent Nuclear Fuel codisposed in a 2-Defense High-Level Waste (2-DHLW)/2-Multi-Canister Overpack (MCO) Waste Package (WP) and emplaced in a monitored geologic repository (MGR) (see Attachment I). The scope of this calculation is limited to the determination of the effective neutron multiplication factor (k eff ) for both intact and degraded mode internal configurations of the codisposal waste package. This calculation will support the analysis that will be performed to demonstrate the technical viability for disposing of U-metal (N Reactor) spent nuclear fuel in the potential MGR

Multi-fuel reformers for fuel cells used in transportation. Phase 1: Multi-fuel reformers

Science.gov (United States)

1994-05-01

DOE has established the goal, through the Fuel Cells in Transportation Program, of fostering the rapid development and commercialization of fuel cells as economic competitors for the internal combustion engine. Central to this goal is a safe feasible means of supplying hydrogen of the required purity to the vehicular fuel cell system. Two basic strategies are being considered: (1) on-board fuel processing whereby alternative fuels such as methanol, ethanol or natural gas stored on the vehicle undergo reformation and subsequent processing to produce hydrogen, and (2) on-board storage of pure hydrogen provided by stationary fuel processing plants. This report analyzes fuel processor technologies, types of fuel and fuel cell options for on-board reformation. As the Phase 1 of a multi-phased program to develop a prototype multi-fuel reformer system for a fuel cell powered vehicle, the objective of this program was to evaluate the feasibility of a multi-fuel reformer concept and to select a reforming technology for further development in the Phase 2 program, with the ultimate goal of integration with a DOE-designated fuel cell and vehicle configuration. The basic reformer processes examined in this study included catalytic steam reforming (SR), non-catalytic partial oxidation (POX) and catalytic partial oxidation (also known as Autothermal Reforming, or ATR). Fuels under consideration in this study included methanol, ethanol, and natural gas. A systematic evaluation of reforming technologies, fuels, and transportation fuel cell applications was conducted for the purpose of selecting a suitable multi-fuel processor for further development and demonstration in a transportation application.

Fuel Cell Electric Vehicle Composite Data Products | Hydrogen and Fuel

Science.gov (United States)

Cells | NREL Vehicle Composite Data Products Fuel Cell Electric Vehicle Composite Data Products The following composite data products (CDPs) focus on current fuel cell electric vehicle evaluations Cell Operation Hour Groups CDP FCEV 39, 2/19/16 Comparison of Fuel Cell Stack Operation Hours and Miles

Uniqueness of magnetotomography for fuel cells and fuel cell stacks

International Nuclear Information System (INIS)

Lustfeld, H; Hirschfeld, J; Reissel, M; Steffen, B

2009-01-01

The criterion for the applicability of any tomographic method is its ability to construct the desired inner structure of a system from external measurements, i.e. to solve the inverse problem. Magnetotomography applied to fuel cells and fuel cell stacks aims at determining the inner current densities from measurements of the external magnetic field. This is an interesting idea since in those systems the inner electric current densities are large, several hundred mA per cm 2 and therefore relatively high external magnetic fields can be expected. Still the question remains how uniquely the inverse problem can be solved. Here we present a proof that by exploiting Maxwell's equations extensively the inverse problem of magnetotomography becomes unique under rather mild assumptions and we show that these assumptions are fulfilled in fuel cells and fuel cell stacks. Moreover, our proof holds true for any other device fulfilling the assumptions listed here. Admittedly, our proof has one caveat: it does not contain an estimate of the precision requirements the measurements need to fulfil for enabling reconstruction of the inner current densities from external magnetic fields.

Commercializing fuel cells: managing risks

Science.gov (United States)

Bos, Peter B.

Commercialization of fuel cells, like any other product, entails both financial and technical risks. Most of the fuel cell literature has focussed upon technical risks, however, the most significant risks during commercialization may well be associated with the financial funding requirements of this process. Successful commercialization requires an integrated management of these risks. Like any developing technology, fuel cells face the typical 'Catch-22' of commercialization: "to enter the market, the production costs must come down, however, to lower these costs, the cumulative production must be greatly increased, i.e. significant market penetration must occur". Unless explicit steps are taken to address this dilemma, fuel cell commercialization will remain slow and require large subsidies for market entry. To successfully address this commercialization dilemma, it is necessary to follow a market-driven commercialization strategy that identifies high-value entry markets while minimizing the financial and technical risks of market entry. The financial and technical risks of fuel cell commercialization are minimized, both for vendors and end-users, with the initial market entry of small-scale systems into high-value stationary applications. Small-scale systems, in the order of 1-40 kW, benefit from economies of production — as opposed to economies to scale — to attain rapid cost reductions from production learning and continuous technological innovation. These capital costs reductions will accelerate their commercialization through market pull as the fuel cell systems become progressively more viable, starting with various high-value stationary and, eventually, for high-volume mobile applications. To facilitate market penetration via market pull, fuel cell systems must meet market-derived economic and technical specifications and be compatible with existing market and fuels infrastructures. Compatibility with the fuels infrastructure is facilitated by a

MICROBIAL FUEL CELL

DEFF Research Database (Denmark)

2008-01-01

A novel microbial fuel cell construction for the generation of electrical energy. The microbial fuel cell comprises: (i) an anode electrode, (ii) a cathode chamber, said cathode chamber comprising an in let through which an influent enters the cathode chamber, an outlet through which an effluent...

Low contaminant formic acid fuel for direct liquid fuel cell

Science.gov (United States)

Masel, Richard I [Champaign, IL; Zhu, Yimin [Urbana, IL; Kahn, Zakia [Palatine, IL; Man, Malcolm [Vancouver, CA

2009-11-17

A low contaminant formic acid fuel is especially suited toward use in a direct organic liquid fuel cell. A fuel of the invention provides high power output that is maintained for a substantial time and the fuel is substantially non-flammable. Specific contaminants and contaminant levels have been identified as being deleterious to the performance of a formic acid fuel in a fuel cell, and embodiments of the invention provide low contaminant fuels that have improved performance compared to known commercial bulk grade and commercial purified grade formic acid fuels. Preferred embodiment fuels (and fuel cells containing such fuels) including low levels of a combination of key contaminants, including acetic acid, methyl formate, and methanol.

A French fuel cell prototype

International Nuclear Information System (INIS)

Anon.

2001-01-01

A French prototype of a fuel cell based on the PEM (proton exchange membrane) technology has been designed by Helion, a branch of Technicatome, this fuel cell delivers 300 kW and will be used in naval applications and terrestrial transport. The main advantages of fuel cell are: 1) no contamination, even if the fuel used is natural gas the quantities of CO 2 and CO emitted are respectively 17 and 75 times as little as the maximal quantities allowed by European regulations, 2) efficiency, the electric yield is up to 60 % and can reach 80 % if we include the recovery of heat, 3) silent, the fuel cell itself does not make noise. The present price of fuel cell is the main reason that hampers its industrial development, this price is in fact strongly dependant on the cost of its different components: catalyzers, membranes, bipolar plates and the hydrogen supply. This article gives the technical characteristics of the Helion's fuel cell. (A.C.)

Photoactivated Fuel Cells (PhotoFuelCells. An alternative source of renewable energy with environmental benefits

Directory of Open Access Journals (Sweden)

Stavroula Sfaelou

2016-03-01

Full Text Available This work is a short review of Photoactivated Fuel Cells, that is, photoelectrochemical cells which consume an organic or inorganic fuel to produce renewable electricity or hydrogen. The work presents the basic features of photoactivated fuel cells, their modes of operation, the materials, which are frequently used for their construction and some ideas of cell design both for electricity and solar hydrogen production. Water splitting is treated as a special case of photoactivated fuel cell operation.

Opportunities for PEM fuel cell commercialization : fuel cell electric vehicle demonstration in Shanghai

Energy Technology Data Exchange (ETDEWEB)

Ma, Z.F. [Shanghai Jiao Tong Univ., Shanghai (China). Dept. of Chemical Engineering

2006-07-01

The research and development activities devoted to the development of the proton exchange membrane fuel cell (PEMFC) were discussed with reference to its application in the fuel cell electric vehicle (FCEV). In the past decade, PEMFC technology has been successfully applied in both the automobile and residential sector worldwide. In China, more than one billion RMB yuan has been granted by the Chinese government to develop PEM fuel cell technology over the past 5 years, particularly for commercialization of the fuel cell electric vehicle (FCEV). The City of Shanghai has played a significant role in the FCEV demonstration with involvement by Shanghai Auto Industrial Company (SAIC), Tongji University, Shanghai Jiaotong University, and Shanghai Shenli High Tech Co. Ltd. These participants were involved in the development and integration of the following components into the FCEV: fuel cell engines, batteries, FCEV electric control systems, and primary materials for the fuel cell stack. During the course of the next five year-plan (2006-2010), Shanghai will promote the commercialization of FCEV. More than one thousand FCEVs will be manufactured and an FCEV fleet will be in operation throughout Shanghai City by 2010.

A Review on Cold Start of Proton Exchange Membrane Fuel Cells

Directory of Open Access Journals (Sweden)

Zhongmin Wan

2014-05-01

Full Text Available Successful and rapid startup of proton exchange membrane fuel cells (PEMFCs at subfreezing temperatures (also called cold start is of great importance for their commercialization in automotive and portable devices. In order to maintain good proton conductivity, the water content in the membrane must be kept at a certain level to ensure that the membrane remains fully hydrated. However, the water in the pores of the catalyst layer (CL, gas diffusion layer (GDL and the membrane may freeze once the cell temperature decreases below the freezing point (Tf. Thus, methods which could enable the fuel cell startup without or with slight performance degradation at subfreezing temperature need to be studied. This paper presents an extensive review on cold start of PEMFCs, including the state and phase changes of water in PEMFCs, impacts of water freezing on PEMFCs, numerical and experimental studies on PEMFCs, and cold start strategies. The impacts on each component of the fuel cell are discussed in detail. Related numerical and experimental work is also discussed. It should be mentioned that the cold start strategies, especially the enumerated patents, are of great reference value on the practical cold start process.

Fuel cell cooler-humidifier plate

Science.gov (United States)

Vitale, Nicholas G.; Jones, Daniel O.

2000-01-01

A cooler-humidifier plate for use in a proton exchange membrane (PEM) fuel cell stack assembly is provided. The cooler-humidifier plate combines functions of cooling and humidification within the fuel cell stack assembly, thereby providing a more compact structure, simpler manifolding, and reduced reject heat from the fuel cell. Coolant on the cooler side of the plate removes heat generated within the fuel cell assembly. Heat is also removed by the humidifier side of the plate for use in evaporating the humidification water. On the humidifier side of the plate, evaporating water humidifies reactant gas flowing over a moistened wick. After exiting the humidifier side of the plate, humidified reactant gas provides needed moisture to the proton exchange membranes used in the fuel cell stack assembly. The invention also provides a fuel cell plate that maximizes structural support within the fuel cell by ensuring that the ribs that form the boundaries of channels on one side of the plate have ends at locations that substantially correspond to the locations of ribs on the opposite side of the plate.

Liquid fuel cells

Directory of Open Access Journals (Sweden)

Grigorii L. Soloveichik

2014-08-01

Full Text Available The advantages of liquid fuel cells (LFCs over conventional hydrogen–oxygen fuel cells include a higher theoretical energy density and efficiency, a more convenient handling of the streams, and enhanced safety. This review focuses on the use of different types of organic fuels as an anode material for LFCs. An overview of the current state of the art and recent trends in the development of LFC and the challenges of their practical implementation are presented.

Visual observations of a degraded bundle of irradiated fuel: the Phebus FPT1 test

International Nuclear Information System (INIS)

Barrachin, M.; Bottomley, P.D.

1999-01-01

The international Phebus-FP (Fission Product) project is managed by the Institut de Protection et Surete Nucleaire in collaboration with Electricite de France (EDF), the European Commission (EC), the USNRC (USA), COG (Canada), NUPEC and JAERI (Japan), KAERI (South Korea), PSI and HSK (Switzerland). It is designed to measure the source-term and to study the degradation of irradiated UO 2 fuel in conditions typical of a severe loss of coolant accident in a pressurised water reactor (PWR). In the first test (FPT0), performed in December '93, a bundle of 20 fresh fuel rods and a central Ag-In-Cd control rod underwent a short 15-day irradiation to generate fission products before testing in the Phebus reactor in Cadarache. The second test (FPT1) was performed in July '96, in the same conditions and geometry, but using irradiated fuel (-23 GWd/tU). In the FPT1 test, the bundle was heated to an estimated 3000 K over a period of 30 minutes in order to induce a substantial liquefaction of the bundle. After the test, the bundle was embedded in epoxy and cut at different levels to investigate the mechanisms of the core degradation. This paper reports the visual observations of the degraded FPT1 bundle, very preliminary interpretations about the scenario of degradation and a comparison between the behaviour of the fuel in the FPT0 and FPT1 tests. (author)

Modeling fuel cell stack systems

Energy Technology Data Exchange (ETDEWEB)

Lee, J H [Los Alamos National Lab., Los Alamos, NM (United States); Lalk, T R [Dept. of Mech. Eng., Texas A and M Univ., College Station, TX (United States)

1998-06-15

A technique for modeling fuel cell stacks is presented along with the results from an investigation designed to test the validity of the technique. The technique was specifically designed so that models developed using it can be used to determine the fundamental thermal-physical behavior of a fuel cell stack for any operating and design configuration. Such models would be useful tools for investigating fuel cell power system parameters. The modeling technique can be applied to any type of fuel cell stack for which performance data is available for a laboratory scale single cell. Use of the technique is demonstrated by generating sample results for a model of a Proton Exchange Membrane Fuel Cell (PEMFC) stack consisting of 125 cells each with an active area of 150 cm{sup 2}. A PEMFC stack was also used in the verification investigation. This stack consisted of four cells, each with an active area of 50 cm{sup 2}. Results from the verification investigation indicate that models developed using the technique are capable of accurately predicting fuel cell stack performance. (orig.)

Transport and degradation of fuel compounds in the vadose zone

DEFF Research Database (Denmark)

Christophersen, Mette; Broholm, Mette Martina; Kjeldsen, Peter

2002-01-01

Fuel has been spilled in the vadose zone at many sites. An artificial jet fuel source has been installed in a vadose zone at Airbase Værløse. The field experiment is conducted to investigate the natural attenuation potential in order to obtain better evaluations of the risk for groundwater...... contamination. Field data and calculations of mass in the pore air indicate a large loss within a short period of time. Laboratory experiments and isotopic analysis proves that biodegradation is occurring. The results indicate that for most compounds degradation is significant reducing the concentrations...

Fuel economy and life-cycle cost analysis of a fuel cell hybrid vehicle

Science.gov (United States)

Jeong, Kwi Seong; Oh, Byeong Soo

The most promising vehicle engine that can overcome the problem of present internal combustion is the hydrogen fuel cell. Fuel cells are devices that change chemical energy directly into electrical energy without combustion. Pure fuel cell vehicles and fuel cell hybrid vehicles (i.e. a combination of fuel cell and battery) as energy sources are studied. Considerations of efficiency, fuel economy, and the characteristics of power output in hybridization of fuel cell vehicle are necessary. In the case of Federal Urban Driving Schedule (FUDS) cycle simulation, hybridization is more efficient than a pure fuel cell vehicle. The reason is that it is possible to capture regenerative braking energy and to operate the fuel cell system within a more efficient range by using battery. Life-cycle cost is largely affected by the fuel cell size, fuel cell cost, and hydrogen cost. When the cost of fuel cell is high, hybridization is profitable, but when the cost of fuel cell is less than 400 US$/kW, a pure fuel cell vehicle is more profitable.

GSPEL - Fuel Cell Laboratory

Data.gov (United States)

Federal Laboratory Consortium — The Fuel Cell Lab (FCL)Established to investigate, integrate, testand verifyperformance and technology readiness offuel cell systems and fuel reformers for use with...

Molten carbonate fuel cell

Science.gov (United States)

Kaun, T.D.; Smith, J.L.

1986-07-08

A molten electrolyte fuel cell is disclosed with an array of stacked cells and cell enclosures isolating each cell except for access to gas manifolds for the supply of fuel or oxidant gas or the removal of waste gas. The cell enclosures collectively provide an enclosure for the array and effectively avoid the problems of electrolyte migration and the previous need for compression of stack components. The fuel cell further includes an inner housing about and in cooperation with the array enclosure to provide a manifold system with isolated chambers for the supply and removal of gases. An external insulated housing about the inner housing provides thermal isolation to the cell components.

Hybrid Fuel Cell Technology Overview

Energy Technology Data Exchange (ETDEWEB)

None available

2001-05-31

For the purpose of this STI product and unless otherwise stated, hybrid fuel cell systems are power generation systems in which a high temperature fuel cell is combined with another power generating technology. The resulting system exhibits a synergism in which the combination performs with an efficiency far greater than can be provided by either system alone. Hybrid fuel cell designs under development include fuel cell with gas turbine, fuel cell with reciprocating (piston) engine, and designs that combine different fuel cell technologies. Hybrid systems have been extensively analyzed and studied over the past five years by the Department of Energy (DOE), industry, and others. These efforts have revealed that this combination is capable of providing remarkably high efficiencies. This attribute, combined with an inherent low level of pollutant emission, suggests that hybrid systems are likely to serve as the next generation of advanced power generation systems.

What Happens Inside a Fuel Cell? Developing an Experimental Functional Map of Fuel Cell Performance

KAUST Repository

Brett, Daniel J. L.

2010-08-20

Fuel cell performance is determined by the complex interplay of mass transport, energy transfer and electrochemical processes. The convolution of these processes leads to spatial heterogeneity in the way that fuel cells perform, particularly due to reactant consumption, water management and the design of fluid-flow plates. It is therefore unlikely that any bulk measurement made on a fuel cell will accurately represent performance at all parts of the cell. The ability to make spatially resolved measurements in a fuel cell provides one of the most useful ways in which to monitor and optimise performance. This Minireview explores a range of in situ techniques being used to study fuel cells and describes the use of novel experimental techniques that the authors have used to develop an \\'experimental functional map\\' of fuel cell performance. These techniques include the mapping of current density, electrochemical impedance, electrolyte conductivity, contact resistance and CO poisoning distribution within working PEFCs, as well as mapping the flow of reactant in gas channels using laser Doppler anemometry (LDA). For the high-temperature solid oxide fuel cell (SOFC), temperature mapping, reference electrode placement and the use of Raman spectroscopy are described along with methods to map the microstructural features of electrodes. The combination of these techniques, applied across a range of fuel cell operating conditions, allows a unique picture of the internal workings of fuel cells to be obtained and have been used to validate both numerical and analytical models. © 2010 Wiley-VCH Verlag GmbH& Co. KGaA, Weinheim.

Power assisted fuel cell

Energy Technology Data Exchange (ETDEWEB)

Jarvis, L P; Atwater, T B; Plichta, E J; Cygan, P J [US Army CECOM, Fort Monmouth, NJ (United States). Research Development and Engineering Center

1998-02-01

A hybrid fuel cell demonstrated pulse power capability at pulse power load simulations synonymous with electronics and communications equipment. The hybrid consisted of a 25.0 W Proton Exchange Membrane Fuel Cell (PEMFC) stack in parallel with a two-cell lead-acid battery. Performance of the hybrid PEMFC was superior to either the battery or fuel cell stack alone at the 18.0 W load. The hybrid delivered a flat discharge voltage profile of about 4.0 V over a 5 h radio continuous transmit mode of 18.0 W. (orig.)

A Slurry Biocascade for the Enhanced Degradation of Fuels in Soils

National Research Council Canada - National Science Library

Apitz, Sabine

1994-01-01

.... In the first step of the cascade, the simplest fuel components (e.g., n-alkanes) are biodegraded. Then, the soil is transferred to the next steps in the cascade, in which different "microbial soups" degrade the next groups of hydrocarbons...

Computational Modeling of Degradation of Substituted Benzyltrimethyl Ammonium: Preprint

Energy Technology Data Exchange (ETDEWEB)

Long, H.; Pivovar, B. S.

2014-09-01

The degradation of cations on the alkaline exchange membranes is the major challenge for alkaline membrane fuel cells. In this paper, we investigated the degradation barriers by density functional theory for substituted benzyltrimethyl ammonium (BTMA+) cations, which is one of the most commonly used cations for alkaline exchange membranes. We found that substituted cations with electron-releasing substituent groups at meta-position of the benzyl ring could result in improved degradation barriers. However, after investigating more than thirty substituted BTMA+ cations with ten different substituent groups, the largest improvement of degradation barriers is only 1.6 kcal/mol. This implies that the lifetime of alkaline membrane fuel cells could increase from a few months to a few years by using substituted BTMA+ cations, an encouraging but still limited improvement for real-world applications.

Fuel economy and range estimates for fuel cell powered automobiles

Energy Technology Data Exchange (ETDEWEB)

Steinbugler, M.; Ogden, J. [Princeton Univ., NJ (United States)

1996-12-31

While a number of automotive fuel cell applications have been demonstrated, including a golf cart, buses, and a van, these systems and others that have been proposed have utilized differing configurations ranging from direct hydrogen fuel cell-only power plants to fuel cell/battery hybrids operating on reformed methanol. To date there is no clear consensus on which configuration, from among the possible combinations of fuel cell, peaking device, and fuel type, is the most likely to be successfully commercialized. System simplicity favors direct hydrogen fuel cell vehicles, but infrastructure is lacking. Infrastructure favors a system using a liquid fuel with a fuel processor, but system integration and performance issues remain. A number of studies have analyzed particular configurations on either a system or vehicle scale. The objective of this work is to estimate, within a consistent framework, fuel economies and ranges for a variety of configurations using flexible models with the goal of identifying the most promising configurations and the most important areas for further research and development.

Hydrogen-Oxygen PEM Regenerative Fuel Cell at NASA Glenn Research Center

Science.gov (United States)

Bents, David J.

2004-01-01

The NASA Glenn Research Center has constructed a closed-cycle hydrogen-oxygen PEM regenerative fuel cell (RFC) to explore its potential use as an energy storage device for a high altitude solar electric aircraft. Built up over the last 2 years from specialized hardware and off the shelf components the Glenn RFC is a complete "brassboard" energy storage system which includes all the equipment required to (1) absorb electrical power from an outside source and store it as pressurized hydrogen and oxygen and (2) make electrical power from the stored gases, saving the product water for re-use during the next cycle. It consists of a dedicated hydrogen-oxygen fuel cell stack and an electrolyzer stack, the interconnecting plumbing and valves, cooling pumps, water transfer pumps, gas recirculation pumps, phase separators, storage tanks for oxygen (O2) and hydrogen (H2), heat exchangers, isolation valves, pressure regulators, nitrogen purge provisions, instrumentation, and other components. It specific developmental functions include: (1) Test fuel cells and fuel cell components under repeated closed-cycle operation (nothing escapes; everything is used over and over again). (2) Simulate diurnal charge-discharge cycles (3) Observe long-term system performance and identify degradation and loss mechanisms. (4) Develop safe and convenient operation and control strategies leading to the successful development of mission-capable, flight-weight RFC's.

1986 fuel cell seminar: Program and abstracts

Energy Technology Data Exchange (ETDEWEB)

None

1986-10-01

Ninety nine brief papers are arranged under the following session headings: gas industry's 40 kw program, solid oxide fuel cell technology, phosphoric acid fuel cell technology, molten carbonate fuel cell technology, phosphoric acid fuel cell systems, power plants technology, fuel cell power plant designs, unconventional fuels, fuel cell application and economic assessments, and plans for commerical development. The papers are processed separately for the data base. (DLC)

Hydrogen and fuel cells

International Nuclear Information System (INIS)

2006-06-01

This road-map proposes by the Group Total aims to inform the public on the hydrogen and fuel cells. It presents the hydrogen technology from the production to the distribution and storage, the issues as motor fuel and fuel cells, the challenge for vehicles applications and the Total commitments in the domain. (A.L.B.)

Ansaldo programs on fuel cell vehicles

Energy Technology Data Exchange (ETDEWEB)

Marcenaro, B.G.; Federici, F. [Ansaldo Ricerche Srl, Genova (Italy)

1996-12-31

The growth in traffic and the importance of maintaining a stable ecology at the global scale, particularly with regard to atmospheric pollution, raises the necessity to realize a new generation of vehicles which are more efficient, more economical and compatible with the environment. At European level, the Car of Tomorrow task force has identified fuel cells as a promising alternative propulsion system. Ansaldo Ricerche has been involved in the development of fuel cell vehicles since the early nineties. Current ongoing programs relates to: (1) Fuel cell bus demonstrator (EQHEPP BUS) Test in 1996 (2) Fuel cell boat demonstrator (EQHHPP BOAT) Test in 1997 (3) Fuel cell passenger car prototype (FEVER) Test in 1997 (4) 2nd generation Fuel cell bus (FCBUS) 1996-1999 (5) 2nd generation Fuel cell passenger car (HYDRO-GEN) 1996-1999.

Reforming options for hydrogen production from fossil fuels for PEM fuel cells

Energy Technology Data Exchange (ETDEWEB)

Ersoz, Atilla; Olgun, Hayati [TUBITAK Marmara Research Center, Institute of Energy, Gebze, 41470 Kocaeli (Turkey); Ozdogan, Sibel [Marmara University Faculty of Engineering, Goztepe, 81040 Istanbul (Turkey)

2006-03-09

PEM fuel cell systems are considered as a sustainable option for the future transport sector in the future. There is great interest in converting current hydrocarbon based transportation fuels into hydrogen rich gases acceptable by PEM fuel cells on-board of vehicles. In this paper, we compare the results of our simulation studies for 100kW PEM fuel cell systems utilizing three different major reforming technologies, namely steam reforming (SREF), partial oxidation (POX) and autothermal reforming (ATR). Natural gas, gasoline and diesel are the selected hydrocarbon fuels. It is desired to investigate the effect of the selected fuel reforming options on the overall fuel cell system efficiency, which depends on the fuel processing, PEM fuel cell and auxiliary system efficiencies. The Aspen-HYSYS 3.1 code has been used for simulation purposes. Process parameters of fuel preparation steps have been determined considering the limitations set by the catalysts and hydrocarbons involved. Results indicate that fuel properties, fuel processing system and its operation parameters, and PEM fuel cell characteristics all affect the overall system efficiencies. Steam reforming appears as the most efficient fuel preparation option for all investigated fuels. Natural gas with steam reforming shows the highest fuel cell system efficiency. Good heat integration within the fuel cell system is absolutely necessary to achieve acceptable overall system efficiencies. (author)

Reforming options for hydrogen production from fossil fuels for PEM fuel cells

Science.gov (United States)

Ersoz, Atilla; Olgun, Hayati; Ozdogan, Sibel

PEM fuel cell systems are considered as a sustainable option for the future transport sector in the future. There is great interest in converting current hydrocarbon based transportation fuels into hydrogen rich gases acceptable by PEM fuel cells on-board of vehicles. In this paper, we compare the results of our simulation studies for 100 kW PEM fuel cell systems utilizing three different major reforming technologies, namely steam reforming (SREF), partial oxidation (POX) and autothermal reforming (ATR). Natural gas, gasoline and diesel are the selected hydrocarbon fuels. It is desired to investigate the effect of the selected fuel reforming options on the overall fuel cell system efficiency, which depends on the fuel processing, PEM fuel cell and auxiliary system efficiencies. The Aspen-HYSYS 3.1 code has been used for simulation purposes. Process parameters of fuel preparation steps have been determined considering the limitations set by the catalysts and hydrocarbons involved. Results indicate that fuel properties, fuel processing system and its operation parameters, and PEM fuel cell characteristics all affect the overall system efficiencies. Steam reforming appears as the most efficient fuel preparation option for all investigated fuels. Natural gas with steam reforming shows the highest fuel cell system efficiency. Good heat integration within the fuel cell system is absolutely necessary to achieve acceptable overall system efficiencies.

Fuel Wood Consumption and Species Degradation in South-Western Nigeria: The Ecological Relevance

Directory of Open Access Journals (Sweden)

Orimoogunje Oluwagbenga O.I.

2015-01-01

Full Text Available The continuous dependence of man on fuel and service wood has resulted in serious degradation of the fragile forest ecosystem. Therefore, this study evaluated the sources and patterns of fuel wood and examined the rate of consumption in the study area. This was with the aim to assess the ecological implications of fuelwood consumption on species degradation. The study utilized both, primary and secondary data. Information was extracted from topographic map on the scale of 1: 50,000 and satellites imageries that cover the study area. Questionnaire administration, field observation and weight measurement of fuel wood were carried out. The results showed that the sources of fuel wood for domestic cooking were forest, nearby bush and abandoned farm while the sources of domestic energy were fuel wood (61.17%, charcoal (27%, kerosene (10%, electricity (1.33% and gas (0.5%. Fuel wood for small scale industries were: forest (49.23%, farmland (34.62 and fallow land (16.15%. The trend of fuel wood consumption was on the high side from 1995 to 2011, it was 58% in 1995, 70% in 2000, 82% in 2005 and 92% in 2010 and 2011 respectively. Many valuable economic tree species such as Triplochiton scleroxylon, Nesogordonia papaverifera, and Cordia spp. are near their extinction. Animals such as antelope, wolf and fox are going into extinction while monkey, grasscutter, hare, rabbit were endemic in the study area. The study concluded that the patterns of fuel wood use and fuel wood saturation presents a great danger for biodiversity products and services.

2009 Fuel Cell Market Report, November 2010

Energy Technology Data Exchange (ETDEWEB)

2010-11-01

Fuel cells are electrochemical devices that combine hydrogen and oxygen to produce electricity, water, and heat. Unlike batteries, fuel cells continuously generate electricity, as long as a source of fuel is supplied. Moreover, fuel cells do not burn fuel, making the process quiet, pollution-free and two to three times more efficient than combustion. Fuel cell systems can be a truly zero-emission source of electricity, if the hydrogen is produced from non-polluting sources. Global concerns about climate change, energy security, and air pollution are driving demand for fuel cell technology. More than 630 companies and laboratories in the United States are investing $1 billion a year in fuel cells or fuel cell component technologies. This report provides an overview of trends in the fuel cell industry and markets, including product shipments, market development, and corporate performance. It also provides snapshots of select fuel cell companies, including general.

Orbiter fuel cell improvement assessment

International Nuclear Information System (INIS)

Johnson, R.E.

1981-08-01

The history of fuel cells and the theory of fuel cells is given. Expressions for thermodynamic and electrical efficiencies are developed. The voltage losses due to electrode activation, ohmic resistance and ionic diffusion are discussed. Present limitations of the Orbiter Fuel Cell, as well as proposed enhancements, are given. These enhancements are then evaluated and recommendations are given for fuel cell enhancement both for short-range as well as long-range performance improvement. Estimates of reliability and cost savings are given for enhancements where possible

Massachusetts Fuel Cell Bus Project: Demonstrating a Total Transit Solution for Fuel Cell Electric Buses in Boston

Energy Technology Data Exchange (ETDEWEB)

2017-05-22

The Federal Transit Administration's National Fuel Cell Bus Program focuses on developing commercially viable fuel cell bus technologies. Nuvera is leading the Massachusetts Fuel Cell Bus project to demonstrate a complete transit solution for fuel cell electric buses that includes one bus and an on-site hydrogen generation station for the Massachusetts Bay Transportation Authority (MBTA). A team consisting of ElDorado National, BAE Systems, and Ballard Power Systems built the fuel cell electric bus, and Nuvera is providing its PowerTap on-site hydrogen generator to provide fuel for the bus.

The effect of porosity on performance of phosphoric acid doped polybenzimidazole polymer electrolyte membrane fuel cell

Directory of Open Access Journals (Sweden)

Celik Muhammet

2016-01-01

Full Text Available A polybenzimidazole (PBI based polymer electrolyte fuel cells, which called high temperature polymer electrolyte fuel cells (HT-PEMS, operate at higher temperatures (120-200°C than conventional PEM fuel cells. Although it is known that HT-PEMS have some of the significant advantages as non-humidification requirements for membrane and the lack of liquid water at high temperature in the fuel cell, the generated water as a result of oxygen reduction reaction causes in the degradation of these systems. The generated water absorbed into membrane side interacts with the hydrophilic PBI matrix and it can cause swelling of membrane, so water transport mechanism in a membrane electrode assembly (MEA needs to be well understood and water balance must be calculated in MEA. Therefore, the water diffusion transport across the electrolyte should be determined. In this study, various porosity values of gas diffusion layers are considered in order to investigate the effects of porosity on the water management for two phase flow in fuel cell. Two-dimensional fuel cell with interdigitated flow-field is modelled using COMSOL Multiphysics 4.2a software. The operating temperature and doping level is selected as 160°C and 6.75mol H3PO4/PBI, respectively.

A comparison of sodium borohydride as a fuel for proton exchange membrane fuel cells and for direct borohydride fuel cells

Science.gov (United States)

Wee, Jung-Ho

Two types of fuel cell systems using NaBH 4 aqueous solution as a fuel are possible: the hydrogen/air proton exchange membrane fuel cell (PEMFC) which uses onsite H 2 generated via the NaBH 4 hydrolysis reaction (B-PEMFC) at the anode and the direct borohydride fuel cell (DBFC) system which directly uses NaBH 4 aqueous solution at the anode and air at the cathode. Recently, research on these two types of fuel cells has begun to attract interest due to the various benefits of this liquid fuel for fuel cell systems for portable applications. It might therefore be relevant at this stage to evaluate the relative competitiveness of the two fuel cells. Considering their current technologies and the high price of NaBH 4, this paper evaluated and analyzed the factors influencing the relative favorability of each type of fuel cell. Their relative competitiveness was strongly dependent on the extent of the NaBH 4 crossover. When considering the crossover in DBFC systems, the total costs of the B-PEMFC system were the most competitive among the fuel cell systems. On the other hand, if the crossover problem were to be completely overcome, the total cost of the DBFC system generating six electrons (6e-DBFC) would be very similar to that of the B-PEMFC system. The DBFC system generating eight electrons (8e-DBFC) became even more competitive if the problem of crossover can be overcome. However, in this case, the volume of NaBH 4 aqueous solution consumed by the DBFC was larger than that consumed by the B-PEMFC.

Third International Fuel Cell Conference. Proceedings

Energy Technology Data Exchange (ETDEWEB)

NONE

1999-11-30

The Third International Fuel Cell Conference was held on November 30 to December 3, 1999 in City of Nagoya. A total of 139 papers, including those for plenary, sectional and poster cessions, were presented. In the plenary session, US's DOE presented fuel cell power plant development in the United States, EC fuel cells in perspective and fifth European framework programme, and Japan overview of the New Sunshine Program. In the polymer electrolyte fuel cells sessions, 23 papers were presented, including current status of commercialization and PEMFC systems developed by Toshiba. In the phosphoric acid fuel cells session, 6 papers were presented, including field test results and market developments. In the molten carbonate fuel cells session, 24 papers were presented, including development of 1,000kW MCFC power plant. In the solid oxide fuel cells session, 20 papers were presented, including 100kW SOFC field test results. The other topics include market analysis and fuel processes. (NEDO)

Third International Fuel Cell Conference. Proceedings

Energy Technology Data Exchange (ETDEWEB)

NONE

1999-11-30

The Third International Fuel Cell Conference was held on November 30 to December 3, 1999 in City of Nagoya. A total of 139 papers, including those for plenary, sectional and poster cessions, were presented. In the plenary session, US's DOE presented fuel cell power plant development in the United States, EC fuel cells in perspective and fifth European framework programme, and Japan overview of the New Sunshine Program. In the polymer electrolyte fuel cells sessions, 23 papers were presented, including current status of commercialization and PEMFC systems developed by Toshiba. In the phosphoric acid fuel cells session, 6 papers were presented, including field test results and market developments. In the molten carbonate fuel cells session, 24 papers were presented, including development of 1,000kW MCFC power plant. In the solid oxide fuel cells session, 20 papers were presented, including 100kW SOFC field test results. The other topics include market analysis and fuel processes. (NEDO)

The birth of the fuel cell

Energy Technology Data Exchange (ETDEWEB)

Prohaska, Don

2001-12-01

Everyone knows that Thomas Alva Edison invented the light bulb, Alexander Graham Bell the telephone and that the Otto and Diesel engines were invented by two Germans bearing those names. But who invented the fuel cell? Fuel cells generate electricity with virtually zero pollution by combining gaseous fuels and air. There are different types generally described as high temperature or low temperature fuel cells. Here, Don Prohaska delves into a recently published book: The Birth of the Fuel Cell, by a descendant of one of the fathers of the fuel cell, and sheds new light on the early days of this technology. (Author)

Enhancing the Chemical and Mechanical Durability of Polymer Electrolyte Membranes for Fuel Cell Applications

Science.gov (United States)

Baker, Andrew M.

Polymer electrolyte membrane (PEM) fuel cells are energy conversion devices which generate electricity from the electrochemical reaction of hydrogen and oxygen. Currently, widespread adoption of PEM fuel cell technology is hindered by low component durability and high costs. In this work, strategies were investigated to improve the mechanical and chemical durability of the ion conducting polymer, or ionomer, which comprises the PEM, in order to directly address these limitations. Owing to their exceptional mechanical properties, carbon nanotubes (CNTs) were investigated for mechanical reinforcement of the PEM. Because of their electronic conductivity, which diminishes cell performance, two strategies were developed to enable the use of CNTs as PEM reinforcement. These systems result in enhanced mechanical properties without sacrificing performance of the PEM during operation. Further, when coated with ceria (CeO2), which scavenges radicals that are generated during operation and cause PEM chemical degradation by attacking vulnerable chemical groups in the ionomer, MWCNTs further improved PEM chemical durability. During cell fabrication, conditioning, and discharge, Ce rapidly migrates between the PEM and catalyst layers (CLs), which reduces catalyst efficiency and leaves areas of the cell defenseless against radical attacks. Therefore, in order to stabilize Ce and localize it to areas of highest radical generation, it is critical to understand and identify the relative influences of different migration mechanisms. Using a novel elemental analysis technique, Ce migration was characterized due to potential and concentration gradients, water flux, and degradation of Ce-exchanged sulfonic acid groups within the PEM. Additionally, Zr-doped ceria was employed to resist migration due to ionomer degradation which improved cell durability, without reducing performance, resulting in PEM Ce stabilization near its initial concentrations after > 1,400 hours of testing. Ce was

Airport electric vehicle powered by fuel cell

Science.gov (United States)

Fontela, Pablo; Soria, Antonio; Mielgo, Javier; Sierra, José Francisco; de Blas, Juan; Gauchia, Lucia; Martínez, Juan M.

Nowadays, new technologies and breakthroughs in the field of energy efficiency, alternative fuels and added-value electronics are leading to bigger, more sustainable and green thinking applications. Within the Automotive Industry, there is a clear declaration of commitment with the environment and natural resources. The presence of passenger vehicles of hybrid architecture, public transport powered by cleaner fuels, non-aggressive utility vehicles and an encouraging social awareness, are bringing to light a new scenario where conventional and advanced solutions will be in force. This paper presents the evolution of an airport cargo vehicle from battery-based propulsion to a hybrid power unit based on fuel cell, cutting edge batteries and hydrogen as a fuel. Some years back, IBERIA (Major Airline operating in Spain) decided to initiate the replacement of its diesel fleet for battery ones, aiming at a reduction in terms of contamination and noise in the surrounding environment. Unfortunately, due to extreme operating conditions in airports (ambient temperature, intensive use, dirtiness, …), batteries suffered a very severe degradation, which took its toll in terms of autonomy. This reduction in terms of autonomy together with the long battery recharge time made the intensive use of this fleet impractical in everyday demanding conditions.

Fuel cell water transport

Science.gov (United States)

Vanderborgh, Nicholas E.; Hedstrom, James C.

1990-01-01

The moisture content and temperature of hydrogen and oxygen gases is regulated throughout traverse of the gases in a fuel cell incorporating a solid polymer membrane. At least one of the gases traverses a first flow field adjacent the solid polymer membrane, where chemical reactions occur to generate an electrical current. A second flow field is located sequential with the first flow field and incorporates a membrane for effective water transport. A control fluid is then circulated adjacent the second membrane on the face opposite the fuel cell gas wherein moisture is either transported from the control fluid to humidify a fuel gas, e.g., hydrogen, or to the control fluid to prevent excess water buildup in the oxidizer gas, e.g., oxygen. Evaporation of water into the control gas and the control gas temperature act to control the fuel cell gas temperatures throughout the traverse of the fuel cell by the gases.

A validated dynamic model of the first marine molten carbonate fuel cell

International Nuclear Information System (INIS)

Ovrum, E.; Dimopoulos, G.

2012-01-01

In this work we present a modular, dynamic and multi-dimensional model of a molten carbonate fuel cell (MCFC) onboard the offshore supply vessel “Viking Lady” serving as an auxiliary power unit. The model is able to capture detailed thermodynamic, heat transfer and electrochemical reaction phenomena within the fuel cell layers. The model has been calibrated and validated with measured performance data from a prototype installation onboard the vessel. The model is able to capture detailed thermodynamic, heat transfer and electrochemical reaction phenomena within the fuel cell layers. The model has been calibrated and validated with measured performance data from a prototype installation onboard the offshore supply vessel. The calibration process included parameter identification, sensitivity analysis to identify the critical model parameters, and iterative calibration of these to minimize the overall prediction error. The calibrated model has a low prediction error of 4% for the operating range of the cell, exhibiting at the same time a physically sound qualitative behavior in terms of thermodynamic heat transfer and electrochemical phenomena, both on steady-state and transient operation. The developed model is suitable for a wide range of studies covering the aspects of thermal efficiency, performance, operability, safety and endurance/degradation, which are necessary to introduce fuel cells in ships. The aim of this MCFC model is to aid to the introduction, design, concept approval and verification of environmentally friendly marine applications such as fuel cells, in a cost-effective, fast and safe manner. - Highlights: ► We model the first marine molten carbonate fuel cell auxiliary power unit. ► The model is distributed spatially and models both steady state and transients. ► The model is validated against experimental data. ► The paper illustrates how the model can be used in safety and reliability studies.

Novel materials for fuel cells operating on liquid fuels

Directory of Open Access Journals (Sweden)

César A. C. Sequeira

2017-05-01

Full Text Available Towards commercialization of fuel cell products in the coming years, the fuel cell systems are being redefined by means of lowering costs of basic elements, such as electrolytes and membranes, electrode and catalyst materials, as well as of increasing power density and long-term stability. Among different kinds of fuel cells, low-temperature polymer electrolyte membrane fuel cells (PEMFCs are of major importance, but their problems related to hydrogen storage and distribution are forcing the development of liquid fuels such as methanol, ethanol, sodium borohydride and ammonia. In respect to hydrogen, methanol is cheaper, easier to handle, transport and store, and has a high theoretical energy density. The second most studied liquid fuel is ethanol, but it is necessary to note that the highest theoretically energy conversion efficiency should be reached in a cell operating on sodium borohydride alkaline solution. It is clear that proper solutions need to be developed, by using novel catalysts, namely nanostructured single phase and composite materials, oxidant enrichment technologies and catalytic activity increasing. In this paper these main directions will be considered.

14 CFR 31.45 - Fuel cells.

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Fuel cells. 31.45 Section 31.45 Aeronautics... STANDARDS: MANNED FREE BALLOONS Design Construction § 31.45 Fuel cells. If fuel cells are used, the fuel cells, their attachments, and related supporting structure must be shown by tests to be capable of...

Status and promise of fuel cell technology

Energy Technology Data Exchange (ETDEWEB)

Williams, M.C. [National Energy Technology Lab., Pittsburgh, PA (United States). Dept. of Energy

2001-09-01

The niche or early entry market penetration by ONSI and its phosphoric acid fuel cell technology has proven that fuel cells are reliable and suitable for premium power and other opportunity fuel niche market applications. Now, new fuel cell technologies - solid oxide fuel cells, molten carbonate fuel cells, and polymer electrolyte fuel cells - are being developed for near-term distributed generation shortly after 2003. Some of the evolving fuel cell systems are incorporating gas turbines in hybrid configurations. The combination of the gas turbine with the fuel cell promises to lower system costs and increase efficiency to enhance market penetration. Market estimates indicate that significant early entry markets exist to sustain the initially high cost of some distributed generation technologies. However, distributed generation technologies must have low introductory first cost, low installation cost, and high system reliability to be viable options in competitive commercial and industrial markets. In the long-term, solid state fuel cell technology with stack costs under $100/kilowatt (kW) promises deeper and wider market penetration in a range of applications including a residential, auxillary power, and the mature distributed generation markets. The solid state energy conversion alliance (SECA) with its vision for fuel cells in 2010 was recently formed to commercialize solid state fuel cells and realize the full potential of the fuel cell technology. Ultimately, the SECA concept could lead to megawatt-size fuel-cell systems for commercial and industrial applications and Vision 21 fuel cell turbine hybrid energy plants in 2015. (orig.)

Fuel cells fuelled by Saccharides

International Nuclear Information System (INIS)

Schechner, P.; Mor, L.; Sabag, N.; Rubin, Z.; Bubis, E.

2005-01-01

Full Text:Saccharides, like glucose, fructose and lactose, are ideal renewable fuels. They have high energy content, are safe, transportable, easy to store, non-flammable, non poisonous, non-volatile, odorless, easy to produce anywhere and abundant. Fuel Cells are electro-chemical devices capable to convert chemical energy into electrical energy from fuels, with theoretical efficiencies higher than 0.8 at room temperatures and with low pollutant emissions. Fuel Cells that can produce electricity form saccharides will be able to replace batteries, power electrical plants from biomass wastes, and serve as engines for transportation. In spite of these advantages, saccharide fuelled fuel cells are no available yet. Two obstacles hinder the feasibility of this potentially revolutionary device. The first is the high stability of the saccharides, which requires a good catalyst to extract the electrons from the saccharide fuel. The second is related to the nature of the Fuel Cells: the physical process takes place at the interface surface between the fuel and the electrode. In order to obtain high densities, materials with high surface to volume ratio are needed. Efforts to overcome these obstacles will be described. The use of saccharides as a fuel was treated from the thermodynamic point of view and compared with other common fuels currently used in fuel cells. We summarize measurements performed in a membrane less Alkaline Fuel Cell, using glucose as a fuel and KOH as electrolyte. The anode has incorporated platinum particles and operated at room temperature. Measurements were done, at different concentrations of glucose, of the Open Circuit Voltage, Polarization Curves and Power Density as function of the Current Density. The maximum Power Density reached was 0.61 mW/cm 2 when the Current density was 2.13 mA/cm 2 and the measured Open Circuit Voltage was 0.771 V

Direct Utilization of Coal Syngas in High Temperature Fuel Cells

Energy Technology Data Exchange (ETDEWEB)

Celik, Ismail B. [West Virginia University, Morgantown, WV (United States)

2014-10-30

This EPSCoR project had two primary goals: (i) to build infrastructure and work force at WVU to support long-term research in the area of fuel cells and related sciences; (ii) study effects of various impurities found in coal-syngas on performance of Solid Oxide Fuel Cells (SOFC). As detailed in this report the WVU research team has made significant accomplishments in both of these areas. What follows is a brief summary of these accomplishments: State-of-the-art test facilities and diagnostic tools have been built and put into use. These include cell manufacturing, half-cell and full-cell test benches, XPS, XRD, TEM, Raman, EDAX, SEM, EIS, and ESEM equipment, unique in-situ measurement techniques and test benches (Environmental EM, Transient Mass-Spectrometer-MS, and IR Optical Temperature measurements). In addition, computational capabilities have been developed culminating in a multi-scale multi-physics fuel cell simulation code, DREAM-SOFC, as well as a Beowulf cluster with 64 CPU units. We have trained 16 graduate students, 10 postdoctoral fellows, and recruited 4 new young faculty members who have actively participated in the EPSCoR project. All four of these faculty members have already been promoted to the tenured associate professor level. With the help of these faculty and students, we were able to secure 14 research awards/contracts amounting to a total of circa $5.0 Million external funding in closely related areas of research. Using the facilities mentioned above, the effects of PH3, HCl, Cl2, and H2S on cell performance have been studied in detail, mechanisms have been identified, and also remedies have been proposed and demonstrated in the laboratory. For example, it has been determined that PH3 reacts rapidly with Ni to from secondary compounds which may become softer or even melt at high temperature and then induce Ni migration to the surface of the cell changing the material and micro-structural properties of the cell drastically. It is found that

Solid electrolyte fuel cells

Science.gov (United States)

Isaacs, H. S.

Progress in the development of functioning solid electrolyte fuel cells is summarized. The solid electrolyte cells perform at 1000 C, a temperature elevated enough to indicate high efficiencies are available, especially if the cell is combined with a steam generator/turbine system. The system is noted to be sulfur tolerant, so coal containing significant amounts of sulfur is expected to yield satisfactory performances with low parasitic losses for gasification and purification. Solid oxide systems are electrically reversible, and are usable in both fuel cell and electrolysis modes. Employing zirconium and yttrium in the electrolyte provides component stability with time, a feature not present with other fuel cells. The chemical reactions producing the cell current are reviewed, along with materials choices for the cathodes, anodes, and interconnections.

Fuel choices for fuel-cell vehicles : well-to-wheel energy and emission impacts

International Nuclear Information System (INIS)

Wang, M.

2002-01-01

Because of their high energy efficiencies and low emissions, fuel-cell vehicles (FCVs) are undergoing extensive research and development. While hydrogen will likely be the ultimate fuel to power fuel-cell vehicles, because of current infrastructure constraints, hydrogen-carrying fuels are being investigated as transitional fuel-cell fuels. A complete well-to-wheels (WTW) evaluation of fuel-cell vehicle energy and emission effects that examines (1) energy feedstock recovery and transportation; (2) fuel production, transportation, and distribution; and (3) vehicle operation must be conducted to assist decision makers in selecting the fuel-cell fuels that achieve the greatest energy and emission benefits. A fuel-cycle model developed at Argonne National Laboratory--called the Greenhouse gases, Regulated Emissions, and Energy use in Transportation (GREET) model--was used to evaluate well-to-wheels energy and emission impacts of various fuel-cell fuels. The results show that different fuel-cell fuels can have significantly different energy and greenhouse gas emission effects. Therefore, if fuel-cell vehicles are to achieve the envisioned energy and emission reduction benefits, pathways for producing the fuels that power them must be carefully examined.

Control of degradation of spent LWR [light-water reactor] fuel during dry storage in an inert atmosphere

International Nuclear Information System (INIS)

Cunningham, M.E.; Simonen, E.P.; Allemann, R.T.; Levy, I.S.; Hazelton, R.F.

1987-10-01

Dry storage of Zircaloy-clad spent fuel in inert gas (referred to as inerted dry storage or IDS) is being developed as an alternative to water pool storage of spent fuel. The objectives of the activities described in this report are to identify potential Zircaloy degradation mechanisms and evaluate their applicability to cladding breach during IDS, develop models of the dominant Zircaloy degradation mechanisms, and recommend cladding temperature limits during IDS to control Zircaloy degradation. The principal potential Zircaloy cladding breach mechanisms during IDS have been identified as creep rupture, stress corrosion cracking (SCC), and delayed hydride cracking (DHC). Creep rupture is concluded to be the primary cladding breach mechanism during IDS. Deformation and fracture maps based on creep rupture were developed for Zircaloy. These maps were then used as the basis for developing spent fuel cladding temperature limits that would prevent cladding breach during a 40-year IDS period. The probability of cladding breach for spent fuel stored at the temperature limit is less than 0.5% per spent fuel rod. 52 refs., 7 figs., 1 tab

Thermodynamic analysis of biofuels as fuels for high temperature fuel cells

Science.gov (United States)

Milewski, Jarosław; Bujalski, Wojciech; Lewandowski, Janusz

2013-02-01

Based on mathematical modeling and numerical simulations, applicativity of various biofuels on high temperature fuel cell performance are presented. Governing equations of high temperature fuel cell modeling are given. Adequate simulators of both solid oxide fuel cell (SOFC) and molten carbonate fuel cell (MCFC) have been done and described. Performance of these fuel cells with different biofuels is shown. Some characteristics are given and described. Advantages and disadvantages of various biofuels from the system performance point of view are pointed out. An analysis of various biofuels as potential fuels for SOFC and MCFC is presented. The results are compared with both methane and hydrogen as the reference fuels. The biofuels are characterized by both lower efficiency and lower fuel utilization factors compared with methane. The presented results are based on a 0D mathematical model in the design point calculation. The governing equations of the model are also presented. Technical and financial analysis of high temperature fuel cells (SOFC and MCFC) are shown. High temperature fuel cells can be fed by biofuels like: biogas, bioethanol, and biomethanol. Operational costs and possible incomes of those installation types were estimated and analyzed. A comparison against classic power generation units is shown. A basic indicator net present value (NPV) for projects was estimated and commented.

Thermodynamic analysis of biofuels as fuels for high temperature fuel cells

Directory of Open Access Journals (Sweden)

Milewski Jarosław

2013-02-01

Full Text Available Based on mathematical modeling and numerical simulations, applicativity of various biofuels on high temperature fuel cell performance are presented. Governing equations of high temperature fuel cell modeling are given. Adequate simulators of both solid oxide fuel cell (SOFC and molten carbonate fuel cell (MCFC have been done and described. Performance of these fuel cells with different biofuels is shown. Some characteristics are given and described. Advantages and disadvantages of various biofuels from the system performance point of view are pointed out. An analysis of various biofuels as potential fuels for SOFC and MCFC is presented. The results are compared with both methane and hydrogen as the reference fuels. The biofuels are characterized by both lower efficiency and lower fuel utilization factors compared with methane. The presented results are based on a 0D mathematical model in the design point calculation. The governing equations of the model are also presented. Technical and financial analysis of high temperature fuel cells (SOFC and MCFC are shown. High temperature fuel cells can be fed by biofuels like: biogas, bioethanol, and biomethanol. Operational costs and possible incomes of those installation types were estimated and analyzed. A comparison against classic power generation units is shown. A basic indicator net present value (NPV for projects was estimated and commented.

Carbon fuel particles used in direct carbon conversion fuel cells

Science.gov (United States)

Cooper, John F.; Cherepy, Nerine

2012-10-09

A system for preparing particulate carbon fuel and using the particulate carbon fuel in a fuel cell. Carbon particles are finely divided. The finely dividing carbon particles are introduced into the fuel cell. A gas containing oxygen is introduced into the fuel cell. The finely divided carbon particles are exposed to carbonate salts, or to molten NaOH or KOH or LiOH or mixtures of NaOH or KOH or LiOH, or to mixed hydroxides, or to alkali and alkaline earth nitrates.

Carbon Fuel Particles Used in Direct Carbon Conversion Fuel Cells

Science.gov (United States)

Cooper, John F.; Cherepy, Nerine

2008-10-21

A system for preparing particulate carbon fuel and using the particulate carbon fuel in a fuel cell. Carbon particles are finely divided. The finely dividing carbon particles are introduced into the fuel cell. A gas containing oxygen is introduced into the fuel cell. The finely divided carbon particles are exposed to carbonate salts, or to molten NaOH or KOH or LiOH or mixtures of NaOH or KOH or LiOH, or to mixed hydroxides, or to alkali and alkaline earth nitrates.

Alternative Fuels Data Center: How Do Fuel Cell Electric Vehicles Work

Science.gov (United States)

vehicles. Hydrogen car image Key Components of a Hydrogen Fuel Cell Electric Car Battery (auxiliary): In an Using Hydrogen? Fuel Cell Electric Vehicles Work Using Hydrogen? to someone by E-mail Share Alternative Fuels Data Center: How Do Fuel Cell Electric Vehicles Work Using Hydrogen? on Facebook Tweet about

Alkaline fuel cells applications

Science.gov (United States)

Kordesch, Karl; Hacker, Viktor; Gsellmann, Josef; Cifrain, Martin; Faleschini, Gottfried; Enzinger, Peter; Fankhauser, Robert; Ortner, Markus; Muhr, Michael; Aronson, Robert R.

On the world-wide automobile market technical developments are increasingly determined by the dramatic restriction on emissions as well as the regimentation of fuel consumption by legislation. Therefore there is an increasing chance of a completely new technology breakthrough if it offers new opportunities, meeting the requirements of resource preservation and emission restrictions. Fuel cell technology offers the possibility to excel in today's motive power techniques in terms of environmental compatibility, consumer's profit, costs of maintenance and efficiency. The key question is economy. This will be decided by the costs of fuel cell systems if they are to be used as power generators for future electric vehicles. The alkaline hydrogen-air fuel cell system with circulating KOH electrolyte and low-cost catalysed carbon electrodes could be a promising alternative. Based on the experiences of Kordesch [K. Kordesch, Brennstoffbatterien, Springer, Wien, 1984, ISBN 3-387-81819-7; K. Kordesch, City car with H 2-air fuel cell and lead-battery, SAE Paper No. 719015, 6th IECEC, 1971], who operated a city car hybrid vehicle on public roads for 3 years in the early 1970s, improved air electrodes plus new variations of the bipolar stack assembly developed in Graz are investigated. Primary fuel choice will be a major issue until such time as cost-effective, on-board hydrogen storage is developed. Ammonia is an interesting option. The whole system, ammonia dissociator plus alkaline fuel cell (AFC), is characterised by a simple design and high efficiency.

Fuel Production from Seawater and Fuel Cells Using Seawater.

Science.gov (United States)

Fukuzumi, Shunichi; Lee, Yong-Min; Nam, Wonwoo

2017-11-23

Seawater is the most abundant resource on our planet and fuel production from seawater has the notable advantage that it would not compete with growing demands for pure water. This Review focuses on the production of fuels from seawater and their direct use in fuel cells. Electrolysis of seawater under appropriate conditions affords hydrogen and dioxygen with 100 % faradaic efficiency without oxidation of chloride. Photoelectrocatalytic production of hydrogen from seawater provides a promising way to produce hydrogen with low cost and high efficiency. Microbial solar cells (MSCs) that use biofilms produced in seawater can generate electricity from sunlight without additional fuel because the products of photosynthesis can be utilized as electrode reactants, whereas the electrode products can be utilized as photosynthetic reactants. Another important source for hydrogen is hydrogen sulfide, which is abundantly found in Black Sea deep water. Hydrogen produced by electrolysis of Black Sea deep water can also be used in hydrogen fuel cells. Production of a fuel and its direct use in a fuel cell has been made possible for the first time by a combination of photocatalytic production of hydrogen peroxide from seawater and dioxygen in the air and its direct use in one-compartment hydrogen peroxide fuel cells to obtain electric power. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Employing Hot Wire Anemometry to Directly Measure the Water Balance of a Commercial Proton Exchange Membrane Fuel Cell Stack

DEFF Research Database (Denmark)

Shakhshir, Saher Al; Berning, Torsten

2016-01-01

Proton exchange membrane fuel cells (PEMFC’s) are currently being commercialized for various applications ranging from automotive (e.g. the Toyota Mirai) to stationary such as powering telecom backup units. In PEMFC’s, oxygen from air is internally combined with hydrogen to form water and produce...... and increased degradation rates. Clearly, a fundamental understanding of all aspects of water management in PEMFC is imperative. This includes the fuel cell water balance, i.e. which fraction of the product water leaves the fuel cell via the anode channels versus the cathode channel. Our research group...... signal received gives valuable insight into heat and mass transfer phenomena in a PEMFC....

Fuel cells principles, design, and analysis

CERN Document Server

Revankar, Shripad T

2014-01-01

""This book covers all essential themes of fuel cells ranging from fundamentals to applications. It includes key advanced topics important for understanding correctly the underlying multi-science phenomena of fuel cell processes. The book does not only cope with traditional fuel cells but also discusses the future concepts of fuel cells. The book is rich on examples and solutions important for applying the theory into practical use.""-Peter Lund, Aalto University, Helsinki""A good introduction to the range of disciplines needed to design, build and test fuel cells.""-Nigel Brandon, Imperial Co

Methanol fuel processor and PEM fuel cell modeling for mobile application

Energy Technology Data Exchange (ETDEWEB)

Chrenko, Daniela [ISAT, University of Burgundy, Rue Mlle Bourgoise, 58000 Nevers (France); Gao, Fei; Blunier, Benjamin; Bouquain, David; Miraoui, Abdellatif [Transport and Systems Laboratory (SeT) - EA 3317/UTBM, Fuel cell Laboratory (FCLAB), University of Technology of Belfort-Montbeliard, Rue Thierry Mieg 90010, Belfort Cedex (France)

2010-07-15

The use of hydrocarbon fed fuel cell systems including a fuel processor can be an entry market for this emerging technology avoiding the problem of hydrogen infrastructure. This article presents a 1 kW low temperature PEM fuel cell system with fuel processor, the system is fueled by a mixture of methanol and water that is converted into hydrogen rich gas using a steam reformer. A complete system model including a fluidic fuel processor model containing evaporation, steam reformer, hydrogen filter, combustion, as well as a multi-domain fuel cell model is introduced. Experiments are performed with an IDATECH FCS1200 trademark fuel cell system. The results of modeling and experimentation show good results, namely with regard to fuel cell current and voltage as well as hydrogen production and pressure. The system is auto sufficient and shows an efficiency of 25.12%. The presented work is a step towards a complete system model, needed to develop a well adapted system control assuring optimized system efficiency. (author)

Fuel cells: Project Volta

Energy Technology Data Exchange (ETDEWEB)

Vellone, R.; Di Mario, F.

1987-09-01

This paper discusses research and development in the field of fuel cell power plants. Reference is made to the Italian research Project Volta. Problems related to research program financing and fuel cell power plant marketing are discussed.

Fuel handling machine and auxiliary systems for a fuel handling cell

International Nuclear Information System (INIS)

Suikki, M.

2013-10-01

This working report is an update for as well as a supplement to an earlier fuel handling machine design (Kukkola and Roennqvist 2006). A focus in the earlier design proposal was primarily on the selection of a mechanical structure and operating principle for the fuel handling machine. This report introduces not only a fuel handling machine design but also auxiliary fuel handling cell equipment and its operation. An objective of the design work was to verify the operating principles of and space allocations for fuel handling cell equipment. The fuel handling machine is a remote controlled apparatus capable of handling intensely radiating fuel assemblies in the fuel handling cell of an encapsulation plant. The fuel handling cell is air tight space radiation-shielded with massive concrete walls. The fuel handling machine is based on a bridge crane capable of traveling in the handling cell along wall tracks. The bridge crane has its carriage provided with a carousel type turntable having mounted thereon both fixed and telescopic masts. The fixed mast has a gripper movable on linear guides for the transfer of fuel assemblies. The telescopic mast has a manipulator arm capable of maneuvering equipment present in the fuel handling cell, as well as conducting necessary maintenance and cleaning operations or rectifying possible fault conditions. The auxiliary fuel handling cell systems consist of several subsystems. The subsystems include a service manipulator, a tool carrier for manipulators, a material hatch, assisting winches, a vacuum cleaner, as well as a hose reel. With the exception of the vacuum cleaner, the devices included in the fuel handling cell's auxiliary system are only used when the actual encapsulation process is not ongoing. The malfunctions of mechanisms or actuators responsible for the motion actions of a fuel handling machine preclude in a worst case scenario the bringing of the fuel handling cell and related systems to a condition appropriate for

Fuel handling machine and auxiliary systems for a fuel handling cell

Energy Technology Data Exchange (ETDEWEB)

Suikki, M. [Optimik Oy, Turku (Finland)

2013-10-15

This working report is an update for as well as a supplement to an earlier fuel handling machine design (Kukkola and Roennqvist 2006). A focus in the earlier design proposal was primarily on the selection of a mechanical structure and operating principle for the fuel handling machine. This report introduces not only a fuel handling machine design but also auxiliary fuel handling cell equipment and its operation. An objective of the design work was to verify the operating principles of and space allocations for fuel handling cell equipment. The fuel handling machine is a remote controlled apparatus capable of handling intensely radiating fuel assemblies in the fuel handling cell of an encapsulation plant. The fuel handling cell is air tight space radiation-shielded with massive concrete walls. The fuel handling machine is based on a bridge crane capable of traveling in the handling cell along wall tracks. The bridge crane has its carriage provided with a carousel type turntable having mounted thereon both fixed and telescopic masts. The fixed mast has a gripper movable on linear guides for the transfer of fuel assemblies. The telescopic mast has a manipulator arm capable of maneuvering equipment present in the fuel handling cell, as well as conducting necessary maintenance and cleaning operations or rectifying possible fault conditions. The auxiliary fuel handling cell systems consist of several subsystems. The subsystems include a service manipulator, a tool carrier for manipulators, a material hatch, assisting winches, a vacuum cleaner, as well as a hose reel. With the exception of the vacuum cleaner, the devices included in the fuel handling cell's auxiliary system are only used when the actual encapsulation process is not ongoing. The malfunctions of mechanisms or actuators responsible for the motion actions of a fuel handling machine preclude in a worst case scenario the bringing of the fuel handling cell and related systems to a condition appropriate for

Strategies for fuel cell product development. Developing fuel cell products in the technology supply chain

International Nuclear Information System (INIS)

Hellman, H.L.

2004-01-01

Due to the high cost of research and development and the broad spectrum of knowledge and competences required to develop fuel cell products, many product-developing firms outsource fuel cell technology, either partly or completely. This article addresses the inter-firm process of fuel cell product development from an Industrial Design Engineering perspective. The fuel cell product development can currently be characterised by a high degree of economic and technical uncertainty. Regarding the technology uncertainty: product-developing firms are more often then not unfamiliar with fuel cell technology technology. Yet there is a high interface complexity between the technology supplied and the product in which it is to be incorporated. In this paper the information exchange in three current fuel cell product development projects is analysed to determine the information required by a product designer to develop a fuel cell product. Technology transfer literature suggests that transfer effectiveness is greatest when the type of technology (technology uncertainty) and the type of relationship between the technology supplier and the recipient are carefully matched. In this line of thinking this paper proposes that the information required by a designer, determined by the design strategy and product/system volume, should be met by an appropriate level of communication interactivity with a technology specialist. (author)

Fuel Cell/Electrochemical Cell Voltage Monitor

Science.gov (United States)

Vasquez, Arturo

2012-01-01

A concept has been developed for a new fuel cell individual-cell-voltage monitor that can be directly connected to a multi-cell fuel cell stack for direct substack power provisioning. It can also provide voltage isolation for applications in high-voltage fuel cell stacks. The technology consists of basic modules, each with an 8- to 16-cell input electrical measurement connection port. For each basic module, a power input connection would be provided for direct connection to a sub-stack of fuel cells in series within the larger stack. This power connection would allow for module power to be available in the range of 9-15 volts DC. The relatively low voltage differences that the module would encounter from the input electrical measurement connection port, coupled with the fact that the module's operating power is supplied by the same substack voltage input (and so will be at similar voltage), provides for elimination of high-commonmode voltage issues within each module. Within each module, there would be options for analog-to-digital conversion and data transfer schemes. Each module would also include a data-output/communication port. Each of these ports would be required to be either non-electrical (e.g., optically isolated) or electrically isolated. This is necessary to account for the fact that the plurality of modules attached to the stack will normally be at a range of voltages approaching the full range of the fuel cell stack operating voltages. A communications/ data bus could interface with the several basic modules. Options have been identified for command inputs from the spacecraft vehicle controller, and for output-status/data feeds to the vehicle.

Enhanced oxygen reduction activity and solid oxide fuel cell performance with a nanoparticles-loaded cathode.

Science.gov (United States)

Zhang, Xiaomin; Liu, Li; Zhao, Zhe; Tu, Baofeng; Ou, Dingrong; Cui, Daan; Wei, Xuming; Chen, Xiaobo; Cheng, Mojie

2015-03-11

Reluctant oxygen-reduction-reaction (ORR) activity has been a long-standing challenge limiting cell performance for solid oxide fuel cells (SOFCs) in both centralized and distributed power applications. We report here that this challenge has been tackled with coloading of (La,Sr)MnO3 (LSM) and Y2O3 stabilized zirconia (YSZ) nanoparticles within a porous YSZ framework. This design dramatically improves ORR activity, enhances fuel cell output (200-300% power improvement), and enables superior stability (no observed degradation within 500 h of operation) from 600 to 800 °C. The improved performance is attributed to the intimate contacts between nanoparticulate YSZ and LSM particles in the three-phase boundaries in the cathode.

Catalysis in high-temperature fuel cells.

Science.gov (United States)

Föger, K; Ahmed, K

2005-02-17

Catalysis plays a critical role in solid oxide fuel cell systems. The electrochemical reactions within the cell--oxygen dissociation on the cathode and electrochemical fuel combustion on the anode--are catalytic reactions. The fuels used in high-temperature fuel cells, for example, natural gas, propane, or liquid hydrocarbons, need to be preprocessed to a form suitable for conversion on the anode-sulfur removal and pre-reforming. The unconverted fuel (economic fuel utilization around 85%) is commonly combusted using a catalytic burner. Ceramic Fuel Cells Ltd. has developed anodes that in addition to having electrochemical activity also are reactive for internal steam reforming of methane. This can simplify fuel preprocessing, but its main advantage is thermal management of the fuel cell stack by endothermic heat removal. Using this approach, the objective of fuel preprocessing is to produce a methane-rich fuel stream but with all higher hydrocarbons removed. Sulfur removal can be achieved by absorption or hydro-desulfurization (HDS). Depending on the system configuration, hydrogen is also required for start-up and shutdown. Reactor operating parameters are strongly tied to fuel cell operational regimes, thus often limiting optimization of the catalytic reactors. In this paper we discuss operation of an authothermal reforming reactor for hydrogen generation for HDS and start-up/shutdown, and development of a pre-reformer for converting propane to a methane-rich fuel stream.

A novel direct carbon fuel cell by approach of tubular solid oxide fuel cells

Energy Technology Data Exchange (ETDEWEB)

Liu, Renzhu; Zhao, Chunhua; Li, Junliang; Zeng, Fanrong; Wang, Shaorong; Wen, Tinglian; Wen, Zhaoyin [CAS Key Laboratory of Materials for Energy Conversion, Shanghai Inorganic Energy Materials and Power Source Engineering Center, Shanghai Institute of Ceramics, Chinese Academy of Sciences (SICCAS), 1295 Dingxi Road, Shanghai 200050 (China)

2010-01-15

A direct carbon fuel cell based on a conventional anode-supported tubular solid oxide fuel cell, which consisted of a NiO-YSZ anode support tube, a NiO-ScSZ anode functional layer, a ScSZ electrolyte film, and a LSM-ScSZ cathode, has been successfully achieved. It used the carbon black as fuel and oxygen as the oxidant, and a preliminary examination of the DCFC has been carried out. The cell generated an acceptable performance with the maximum power densities of 104, 75, and 47 mW cm{sup -2} at 850, 800, and 750 C, respectively. These results demonstrate the feasibility for carbon directly converting to electricity in tubular solid oxide fuel cells. (author)

Climate Change Fuel Cell Program

Energy Technology Data Exchange (ETDEWEB)

Paul Belard

2006-09-21

Verizon is presently operating the largest Distributed Generation Fuel Cell project in the USA. Situated in Long Island, NY, the power plant is composed of seven (7) fuel cells operating in parallel with the Utility grid from the Long Island Power Authority (LIPA). Each fuel cell has an output of 200 kW, for a total of 1.4 mW generated from the on-site plant. The remaining power to meet the facility demand is purchased from LIPA. The fuel cell plant is utilized as a co-generation system. A by-product of the fuel cell electric generation process is high temperature water. The heat content of this water is recovered from the fuel cells and used to drive two absorption chillers in the summer and a steam generator in the winter. Cost savings from the operations of the fuel cells are forecasted to be in excess of $250,000 per year. Annual NOx emissions reductions are equivalent to removing 1020 motor vehicles from roadways. Further, approximately 5.45 million metric tons (5 millions tons) of CO2 per year will not be generated as a result of this clean power generation. The project was partially financed with grants from the New York State Energy R&D Authority (NYSERDA) and from Federal Government Departments of Defense and Energy.

Portable power applications of fuel cells

Energy Technology Data Exchange (ETDEWEB)

Weston, M.; Matcham, J.

2002-07-01

This report describes the state-of-the-art of fuel cell technology for portable power applications. The study involved a comprehensive literature review. Proton exchange membrane fuel cells (PEMFCs) have attracted much more interest than either direct methanol fuel cells (DMFCs) or solid oxide fuel cells (SOFCs). However, issues relating to fuel choice and catalyst design remain with PEMFCs; DMFCs have excellent potential provided issues relating to the conducting membrane can be resolved but the current high temperature of operation and low power density currently makes SOFCs less applicable to portable applications. Available products are listed and the obstacles to market penetration are discussed. The main barriers are cost and the size/weight of fuel cells compared with batteries. Another key problem is the lack of a suitable fuel infrastructure.

Electricity generation by Enterobacter cloacae SU-1 in mediator less microbial fuel cell

Energy Technology Data Exchange (ETDEWEB)

Samrot, Antony V.; Senthilkumar, P.; Pavankumar, K.; Akilandeswari, G.C. [Department of Biotechnology, Sathyabama University, Rajiv Gandhi Salai, Chennai, Tamilnadu (India); Rajalakshmi, N.; Dhathathreyan, K.S. [Center for Fuel Cell Technology ARCI, IITM Research Park, Phase I, 2nd Floor, 6 Kanagam Road, Tharamani, Chennai 600 113, Tamilnadu (India)

2010-08-15

We have investigated a Enterobacter cloacae SU-1, bacteria for mediator less microbial fuel cell with different carbon sources and is found to be more effective as the microorganism is able to transfer electrons directly (exo-electrogenic organism) via the cytochromes or the ubiquinone. These carriers of electrons are in form of stable reversible redox couples, not biologically degraded and not toxic to cell. The major advantage of mediator less microbial fuel cells emphasize that additives in the anolyte is not compatible with the purpose of water purification. The anode chamber with the bacteria is maintained under anaerobic conditions so that the bacteria will undergo anaerobic biochemical pathways like Glycolysis, TCA cycle, Electron Transport Chain (ETC) where electrons and protons are released. Here protons are released in TCA cycle and whereas electrons are released from ETC. The mediator less microbial fuel cell delivered an open circuit potential (OCP) of 0.93 V and power of 3 mW/sq cm. During power generation from the microbes, there was a drop in coulombic efficiency in terms of fluctuations during drawing power, as the carbon source is being utilized for the cell growth. (author)

Interconnection of bundled solid oxide fuel cells

Science.gov (United States)

Brown, Michael; Bessette, II, Norman F; Litka, Anthony F; Schmidt, Douglas S

2014-01-14

A system and method for electrically interconnecting a plurality of fuel cells to provide dense packing of the fuel cells. Each one of the plurality of fuel cells has a plurality of discrete electrical connection points along an outer surface. Electrical connections are made directly between the discrete electrical connection points of adjacent fuel cells so that the fuel cells can be packed more densely. Fuel cells have at least one outer electrode and at least one discrete interconnection to an inner electrode, wherein the outer electrode is one of a cathode and and anode and wherein the inner electrode is the other of the cathode and the anode. In tubular solid oxide fuel cells the discrete electrical connection points are spaced along the length of the fuel cell.

Carbon-based Fuel Cell

Energy Technology Data Exchange (ETDEWEB)

Steven S. C. Chuang

2005-08-31

The direct use of coal in the solid oxide fuel cell to generate electricity is an innovative concept for power generation. The C-fuel cell (carbon-based fuel cell) could offer significant advantages: (1) minimization of NOx emissions due to its operating temperature range of 700-1000 C, (2) high overall efficiency because of the direct conversion of coal to CO{sub 2}, and (3) the production of a nearly pure CO{sub 2} exhaust stream for the direct CO{sub 2} sequestration. The objective of this project is to determine the technical feasibility of using a highly active anode catalyst in a solid oxide fuel for the direct electrochemical oxidation of coal to produce electricity. Results of this study showed that the electric power generation from Ohio No 5 coal (Lower Kittanning) Seam, Mahoning County, is higher than those of coal gas and pure methane on a solid oxide fuel cell assembly with a promoted metal anode catalyst at 950 C. Further study is needed to test the long term activity, selectivity, and stability of anode catalysts.

Fuel cell report to congress

Energy Technology Data Exchange (ETDEWEB)

None, None

2003-02-28

This report describes the status of fuel cells for Congressional committees. It focuses on the technical and economic barriers to the use of fuel cells in transportation, portable power, stationary, and distributed power generation applications, and describes the need for public-private cooperative programs to demonstrate the use of fuel cells in commercial-scale applications by 2012. (Department of Energy, February 2003).

The TMI regenerable solid oxide fuel cell

Science.gov (United States)

Cable, Thomas L.

1995-04-01

Energy storage and production in space requires rugged, reliable hardware which minimizes weight, volume, and maintenance while maximizing power output and usable energy storage. These systems generally consist of photovoltaic solar arrays which operate during sunlight cycles to provide system power and regenerate fuel (hydrogen) via water electrolysis; during dark cycles, hydrogen is converted by the fuel cell into system. The currently preferred configuration uses two separate systems (fuel cell and electrolyzer) in conjunction with photovoltaic cells. Fuel cell/electrolyzer system simplicity, reliability, and power-to-weight and power-to-volume ratios could be greatly improved if both power production (fuel cell) and power storage (electrolysis) functions can be integrated into a single unit. The Technology Management, Inc. (TMI), solid oxide fuel cell-based system offers the opportunity to both integrate fuel cell and electrolyzer functions into one unit and potentially simplify system requirements. Based an the TMI solid oxide fuel cell (SOPC) technology, the TMI integrated fuel cell/electrolyzer utilizes innovative gas storage and operational concepts and operates like a rechargeable 'hydrogen-oxygen battery'. Preliminary research has been completed on improved H2/H2O electrode (SOFC anode/electrolyzer cathode) materials for solid oxide, regenerative fuel cells. Improved H2/H2O electrode materials showed improved cell performance in both fuel cell and electrolysis modes in reversible cell tests. ln reversible fuel cell/electrolyzer mode, regenerative fuel cell efficiencies (ratio of power out (fuel cell mode) to power in (electrolyzer model)) improved from 50 percent (using conventional electrode materials) to over 80 percent. The new materials will allow the TMI SOFC system to operate as both the electrolyzer and fuel cell in a single unit. Preliminary system designs have also been developed which indicate the technical feasibility of using the TMI SOFC

Rapid Evaluation of Power Degradation in Series Connection of Single Feeding Microsized Microbial Fuel Cells

KAUST Repository

Rojas, Jhonathan Prieto; Alqarni, Wejdan Mohammed Mofleh; Hussain, Muhammad Mustafa

2014-01-01

We have developed a sustainable, single feeding, microsized, air-cathode and membrane-free microbial fuel cells with a volume of 40 mu L each, which we have used for rapid evaluation of power generation and viability of a series array of three cells seeking higher voltage levels. Contrary to expectations, the achieved power density was modest (45 mWm(-3)), limited due to non-uniformities in assembly and the single-channel feeding system.

Rapid Evaluation of Power Degradation in Series Connection of Single Feeding Microsized Microbial Fuel Cells

KAUST Repository

Rojas, Jhonathan Prieto

2014-07-08

We have developed a sustainable, single feeding, microsized, air-cathode and membrane-free microbial fuel cells with a volume of 40 mu L each, which we have used for rapid evaluation of power generation and viability of a series array of three cells seeking higher voltage levels. Contrary to expectations, the achieved power density was modest (45 mWm(-3)), limited due to non-uniformities in assembly and the single-channel feeding system.

Durability of Low Platinum Fuel Cells Operating at High Power Density

Energy Technology Data Exchange (ETDEWEB)

Polevaya, Olga [Nuvera Fuel Cells Inc.; Blanchet, Scott [Nuvera Fuel Cells Inc.; Ahluwalia, Rajesh [Argonne National Lab; Borup, Rod [Los-Alamos National Lab; Mukundan, Rangachary [Los-Alamos National Lab

2014-03-19

Understanding and improving the durability of cost-competitive fuel cell stacks is imperative to successful deployment of the technology. Stacks will need to operate well beyond today’s state-of-the-art rated power density with very low platinum loading in order to achieve the cost targets set forth by DOE ($15/kW) and ultimately be competitive with incumbent technologies. An accelerated cost-reduction path presented by Nuvera focused on substantially increasing power density to address non-PGM material costs as well as platinum. The study developed a practical understanding of the degradation mechanisms impacting durability of fuel cells with low platinum loading (≤0.2mg/cm2) operating at high power density (≥1.0W/cm2) and worked out approaches for improving the durability of low-loaded, high-power stack designs. Of specific interest is the impact of combining low platinum loading with high power density operation, as this offers the best chance of achieving long-term cost targets. A design-of-experiments approach was utilized to reveal and quantify the sensitivity of durability-critical material properties to high current density at two levels of platinum loading (the more conventional 0.45 mgPt.cm–1 and the much lower 0.2 mgPt.cm–2) across several cell architectures. We studied the relevance of selected component accelerated stress tests (AST) to fuel cell operation in power producing mode. New stress tests (NST) were designed to investigate the sensitivity to the addition of electrical current on the ASTs, along with combined humidity and load cycles and, eventually, relate to the combined city/highway drive cycle. Changes in the cathode electrochemical surface area (ECSA) and average oxygen partial pressure on the catalyst layer with aging under AST and NST protocols were compared based on the number of completed cycles. Studies showed elevated sensitivity of Pt growth to the potential limits and the initial particle size distribution. The ECSA loss

Electricity generation from palm oil tree empty fruit bunch (EFB) using dual chamber microbial fuel cell (MFC)

Science.gov (United States)

Ghazali, N. F.; Mahmood, N. A. B. N.; Ibrahim, K. A.; Muhammad, S. A. F. S.; Amalina, N. S.

2017-06-01

Microbial fuel cell (MFC) has been discovered and utilized in laboratory scale for electricity production based on microbial degradation of organic compound. However, various source of fuel has been tested and recently complex biomass such as lignocellulose biomass has been focused on. In the present research, oil palm tree empty fruit bunch (EFB) has been tested for power production using dual chamber MFC and power generation analysis has been conducted to address the performance of MFC. In addition, two microorganisms (electric harvesting microbe and cellulose degrading microbe) were used in the MFC operation. The analysis include voltage produced, calculated current and power. The first section in your paper

Sulfur poisoning of Ni/Gadolinium-doped ceria anodes: A long-term study outlining stable solid oxide fuel cell operation

Science.gov (United States)

Riegraf, Matthias; Zekri, Atef; Knipper, Martin; Costa, Rémi; Schiller, Günter; Friedrich, K. Andreas

2018-03-01

This work presents an analysis of the long-term behavior of nickel/gadolinium-doped ceria (CGO) anode-based solid oxide fuel cells (SOFC) under sulfur poisoning conditions. A parameter study of sulfur-induced irreversible long-term degradation of commercial, high-performance single cells was carried out at 900 °C for different H2/N2/H2S fuel gas atmospheres, current densities and Ni/CGO anodes. The poisoning periods of the cells varied from 200 to 1500 h. The possibility of stable long-term Ni/CGO anode operation under sulfur exposure is established and the critical operating regime is outlined. Depending on the operating conditions, two degradation phenomena can be observed. Small degradation of the ohmic resistance was witnessed for sulfur exposure times of approximately 1000 h. Moreover, degradation of the anode charge transfer resistance was observed to be triggered by the combination of a small anodic potential step and high sulfur coverage on Ni. The microstructural evolution of altered Ni/CGO anodes was examined post-mortem by means of SEM and FIB/SEM, and is correlated to the anode performance degradation under critical operating conditions, establishing Ni depletion, porosity increase and a tripe phase boundary density decrease in the anode functional layer. It is shown that short-term sulfur poisoning behavior can be used to assess long-term stability.

Fault detection and isolation of high temperature proton exchange membrane fuel cell stack under the influence of degradation

Science.gov (United States)

Jeppesen, Christian; Araya, Samuel Simon; Sahlin, Simon Lennart; Thomas, Sobi; Andreasen, Søren Juhl; Kær, Søren Knudsen

2017-08-01

This study proposes a data-drive impedance-based methodology for fault detection and isolation of low and high cathode stoichiometry, high CO concentration in the anode gas, high methanol vapour concentrations in the anode gas and low anode stoichiometry, for high temperature PEM fuel cells. The fault detection and isolation algorithm is based on an artificial neural network classifier, which uses three extracted features as input. Two of the proposed features are based on angles in the impedance spectrum, and are therefore relative to specific points, and shown to be independent of degradation, contrary to other available feature extraction methods in the literature. The experimental data is based on a 35 day experiment, where 2010 unique electrochemical impedance spectroscopy measurements were recorded. The test of the algorithm resulted in a good detectability of the faults, except for high methanol vapour concentration in the anode gas fault, which was found to be difficult to distinguish from a normal operational data. The achieved accuracy for faults related to CO pollution, anode- and cathode stoichiometry is 100% success rate. Overall global accuracy on the test data is 94.6%.

Advances in fuel cell vehicle design

Science.gov (United States)

Bauman, Jennifer

Factors such as global warming, dwindling fossil fuel reserves, and energy security concerns combine to indicate that a replacement for the internal combustion engine (ICE) vehicle is needed. Fuel cell vehicles have the potential to address the problems surrounding the ICE vehicle without imposing any significant restrictions on vehicle performance, driving range, or refuelling time. Though there are currently some obstacles to overcome before attaining the widespread commercialization of fuel cell vehicles, such as improvements in fuel cell and battery durability, development of a hydrogen infrastructure, and reduction of high costs, the fundamental concept of the fuel cell vehicle is strong: it is efficient, emits zero harmful emissions, and the hydrogen fuel can be produced from various renewable sources. Therefore, research on fuel cell vehicle design is imperative in order to improve vehicle performance and durability, increase efficiency, and reduce costs. This thesis makes a number of key contributions to the advancement of fuel cell vehicle design within two main research areas: powertrain design and DC/DC converters. With regards to powertrain design, this research first analyzes various powertrain topologies and energy storage system types. Then, a novel fuel cell-battery-ultracapacitor topology is presented which shows reduced mass and cost, and increased efficiency, over other promising topologies found in the literature. A detailed vehicle simulator is created in MATLAB/Simulink in order to simulate and compare the novel topology with other fuel cell vehicle powertrain options. A parametric study is performed to optimize each powertrain and general conclusions for optimal topologies, as well as component types and sizes, for fuel cell vehicles are presented. Next, an analytical method to optimize the novel battery-ultracapacitor energy storage system based on maximizing efficiency, and minimizing cost and mass, is developed. This method can be applied

Cornell Fuel Cell Institute: Materials Discovery to Enable Fuel Cell Technologies

Energy Technology Data Exchange (ETDEWEB)

Abruna, H.D.; DiSalvo, Francis J.

2012-06-29

The discovery and understanding of new, improved materials to advance fuel cell technology are the objectives of the Cornell Fuel Cell Institute (CFCI) research program. CFCI was initially formed in 2003. This report highlights the accomplishments from 2006-2009. Many of the grand challenges in energy science and technology are based on the need for materials with greatly improved or even revolutionary properties and performance. This is certainly true for fuel cells, which have the promise of being highly efficient in the conversion of chemical energy to electrical energy. Fuel cells offer the possibility of efficiencies perhaps up to 90 % based on the free energy of reaction. Here, the challenges are clearly in the materials used to construct the heart of the fuel cell: the membrane electrode assembly (MEA). The MEA consists of two electrodes separated by an ionically conducting membrane. Each electrode is a nanocomposite of electronically conducting catalyst support, ionic conductor and open porosity, that together form three percolation networks that must connect to each catalyst nanoparticle; otherwise the catalyst is inactive. This report highlights the findings of the three years completing the CFCI funding, and incudes developments in materials for electrocatalyts, catalyst supports, materials with structured and functional porosity for electrodes, and novel electrolyte membranes. The report also discusses developments at understanding electrocatalytic mechanisms, especially on novel catalyst surfaces, plus in situ characterization techniques and contributions from theory. Much of the research of the CFCI continues within the Energy Materials Center at Cornell (emc2), a DOE funded, Office of Science Energy Frontier Research Center (EFRC).

National fuel cell bus program : proterra fuel cell hybrid bus report, Columbia demonstration.

Science.gov (United States)

2011-10-01

This report summarizes the experience and early results from a fuel cell bus demonstration funded by the Federal Transit Administration (FTA) under the National Fuel Cell Bus Program. A team led by the Center for Transportation and the Environment an...

The TMI Regenerative Solid Oxide Fuel Cell

Science.gov (United States)

Cable, Thomas L.; Ruhl, Robert C.; Petrik, Michael

1996-01-01

Energy storage and production in space requires rugged, reliable hardware which minimizes weight, volume, and maintenance while maximizing power output and usable energy storage. Systems generally consist of photovoltaic solar arrays which operate (during sunlight cycles) to provide system power and regenerate fuel (hydrogen) via water electrolysis and (during dark cycles) fuel cells convert hydrogen into electricity. Common configurations use two separate systems (fuel cell and electrolyzer) in conjunction with photovoltaic cells. Reliability, power to weight and power to volume ratios could be greatly improved if both power production (fuel cells) and power storage (electrolysis) functions can be integrated into a single unit. The solid oxide fuel cell (SOFC) based design integrates fuel cell and electrolyzer functions and potentially simplifies system requirements. The integrated fuel cell/electrolyzer design also utilizes innovative gas storage concepts and operates like a rechargeable 'hydrogen-oxygen battery'. Preliminary research has been completed on improved H2/H20 electrode (SOFC anode/electrolyzer cathode) materials for regenerative fuel cells. Tests have shown improved cell performance in both fuel and electrolysis modes in reversible fuel cell tests. Regenerative fuel cell efficiencies, ratio of power out (fuel cell mode) to power in (electrolyzer mode), improved from 50 percent using conventional electrode materials to over 80 percent. The new materials will allow a single SOFC system to operate as both the electolyzer and fuel cell. Preliminary system designs have also been developed to show the technical feasibility of using the design for space applications requiring high energy storage efficiencies and high specific energy. Small space systems also have potential for dual-use, terrestrial applications.

Stability study of cermet-supported solid oxide fuel cells with bi-layered electrolyte

Energy Technology Data Exchange (ETDEWEB)

Zhang, Xinge; Gazzarri, Javier; Robertson, Mark; Deces-Petit, Cyrille [National Research Council, Institute for Fuel Cell Innovation, 4250 Wesbrook Mall, Vancouver, BC (Canada); Kesler, Olivera [Department of Mechanical and Industrial Engineering, University of Toronto, 5 King' s College Road, Toronto, ON (Canada)

2008-12-01

Performance and stability of five cermet-supported button-type solid oxide fuel cells featuring a bi-layered electrolyte (SSZ/SDC), an SSC cathode, and a Ni-SSZ anode, were analyzed using polarization curves, impedance spectroscopy, and post-mortem SEM observation. The cell performance degradation at 650 C in H{sub 2}/air both with and without DC bias conditions was manifested primarily as an increase in polarization resistance, approximately at a rate of 2.3 m{omega} cm{sup 2} h{sup -1} at OCV, suggesting a decrease in electrochemical kinetics as the main phenomenon responsible for the performance decay. In addition, the initial series resistance was about ten times higher than the calculated resistance corresponding to the electrolyte, reflecting a possible inter-reaction between the electrolyte layers that occurred during the sintering stage. In situ and ex situ sintered cathodes showed no obvious difference in cell performance or decay rate. The stability of the cells with and without electrical load was also investigated and no significant influence of DC bias was recorded. Based on the experimental results presented, we preliminarily attribute the performance degradation to electrochemical and microstructural degradation of the cathode. (author)

Stability study of cermet-supported solid oxide fuel cells with bi-layered electrolyte

Science.gov (United States)

Zhang, Xinge; Gazzarri, Javier; Robertson, Mark; Decès-Petit, Cyrille; Kesler, Olivera

Performance and stability of five cermet-supported button-type solid oxide fuel cells featuring a bi-layered electrolyte (SSZ/SDC), an SSC cathode, and a Ni-SSZ anode, were analyzed using polarization curves, impedance spectroscopy, and post-mortem SEM observation. The cell performance degradation at 650 °C in H 2/air both with and without DC bias conditions was manifested primarily as an increase in polarization resistance, approximately at a rate of 2.3 mΩ cm 2 h -1 at OCV, suggesting a decrease in electrochemical kinetics as the main phenomenon responsible for the performance decay. In addition, the initial series resistance was about ten times higher than the calculated resistance corresponding to the electrolyte, reflecting a possible inter-reaction between the electrolyte layers that occurred during the sintering stage. In situ and ex situ sintered cathodes showed no obvious difference in cell performance or decay rate. The stability of the cells with and without electrical load was also investigated and no significant influence of DC bias was recorded. Based on the experimental results presented, we preliminarily attribute the performance degradation to electrochemical and microstructural degradation of the cathode.

Fuel cell APU for commercial aircraft

Energy Technology Data Exchange (ETDEWEB)

Daggett, D.L. [Boeing Commercial Airplane, Seattle, WA (United States); Lowery, N. [Princeton Univ., Princeton, NJ (United States); Wittmann, J. [Technische Univ. Muenchen (Germany)

2005-07-01

The Boeing Company has always sought to improve fuel efficiency in commercial aircraft. An opportunity now exists to explore technology that will allow fuel efficiency improvements to be achieved while simultaneously reducing emissions. Replacing the current aircraft gas turbine-powered Auxiliary Power Unit with a hybrid Solid Oxide Fuel Cell is anticipated to greatly improve fuel efficiency, reduce emissions and noise as well as improve airplane performance. However, there are several technology hurdles that need to be overcome. If SOFC technology is to be matured for the betterment of the earth community, the fuel cell industry, aerospace manufacturers and other end users all need to work together to overcome these challenges. Aviation has many of the same needs in fuel cell technology as other sectors, such as reducing cost and improving reliability and fuel efficiency in order to commercialize the technology. However, there are other distinct aerospace needs that will not necessarily be addressed by the industrial sector. These include development of lightweight materials and small-volume fuel cell systems that can reform hydrocarbon fuels. Aviation also has higher levels of safety requirements. Other transportation modes share the same requirement for vibration and shock tolerant fuel cell stacks. Lastly, as fuel cells are anticipated to be operated in flight, they must be capable of operating over a wide range of atmospheric conditions. By itself, the aviation sector does not appear to offer enough of a potential market to justify the investment required by any one manufacturer to develop fuel cells for APU replacements. Therefore, means must be found to modularize components and make SOFC stacks sufficiently similar to industrial units so that manufacturing economy of scales can be brought to bear. Government R and D and industry support are required to advance the technology. Because aerospace fuel cells will be higher performing units, the benefits of

Electrolytes for solid oxide fuel cells

Science.gov (United States)

Fergus, Jeffrey W.

The high operating temperature of solid oxide fuel cells (SOFCs), as compared to polymer electrolyte membrane fuel cells (PEMFCs), improves tolerance to impurities in the fuel, but also creates challenges in the development of suitable materials for the various fuel cell components. In response to these challenges, intermediate temperature solid oxide fuel cells (IT-SOFCs) are being developed to reduce high-temperature material requirements, which will extend useful lifetime, improve durability and reduce cost, while maintaining good fuel flexibility. A major challenge in reducing the operating temperature of SOFCs is the development of solid electrolyte materials with sufficient conductivity to maintain acceptably low ohmic losses during operation. In this paper, solid electrolytes being developed for solid oxide fuel cells, including zirconia-, ceria- and lanthanum gallate-based materials, are reviewed and compared. The focus is on the conductivity, but other issues, such as compatibility with electrode materials, are also discussed.

Electrolytes for solid oxide fuel cells

Energy Technology Data Exchange (ETDEWEB)

Fergus, Jeffrey W. [Auburn University, Materials Research and Education Center, 275 Wilmore Laboratories, Auburn, AL 36849 (United States)

2006-11-08

The high operating temperature of solid oxide fuel cells (SOFCs), as compared to polymer electrolyte membrane fuel cells (PEMFCs), improves tolerance to impurities in the fuel, but also creates challenges in the development of suitable materials for the various fuel cell components. In response to these challenges, intermediate temperature solid oxide fuel cells (IT-SOFCs) are being developed to reduce high-temperature material requirements, which will extend useful lifetime, improve durability and reduce cost, while maintaining good fuel flexibility. A major challenge in reducing the operating temperature of SOFCs is the development of solid electrolyte materials with sufficient conductivity to maintain acceptably low ohmic losses during operation. In this paper, solid electrolytes being developed for solid oxide fuel cells, including zirconia-, ceria- and lanthanum gallate-based materials, are reviewed and compared. The focus is on the conductivity, but other issues, such as compatibility with electrode materials, are also discussed. (author)

High temperature corrosion of metallic interconnects in solid oxide fuel cells

Directory of Open Access Journals (Sweden)

Bastidas, D. M.

2006-12-01

Full Text Available Research and development has made it possible to use metallic interconnects in solid oxide fuel cells (SOFC instead of ceramic materials. The use of metallic interconnects was formerly hindered by the high operating temperature, which made the interconnect degrade too much and too fast to be an efficient alternative. When the operating temperature was lowered, the use of metallic interconnects proved to be favourable since they are easier and cheaper to produce than ceramic interconnects. However, metallic interconnects continue to be degraded despite the lowered temperature, and their corrosion products contribute to electrical degradation in the fuel cell. Coatings of nickel, chromium, aluminium, zinc, manganese, yttrium or lanthanum between the interconnect and the electrodes reduce this degradation during operation

El uso de interconectores metálicos en pilas de combustible de óxido sólido (SOFC en sustitución de materiales cerámicos ha sido posible gracias a la investigación y desarrollo de nuevos materiales metálicos. Inicialmente, el uso de interconectores metálicos fue limitado, debido a la elevada temperatura de trabajo, ocasionando de forma rápida la degradación del material, lo que impedía que fuesen una alternativa. A medida que la temperatura de trabajo de las SOFC descendió, el uso de interconectores metálicos demostró ser una buena alternativa, dado que son más fáciles de fabricar y más baratos que los interconectores cerámicos. Sin embargo, los interconectores metálicos continúan degradándose a pesar de descender la temperatura a la que operan las SOFC y, asimismo, los productos de corrosión favorecen las pérdidas eléctricas de la pila de combustible. Recubrimientos de níquel, cromo, aluminio, zinc, manganeso, itrio y lantano entre el interconector y los electrodos reduce dichas pérdidas eléctricas.

Highly durable anode supported solid oxide fuel cell with an infiltrated cathode

DEFF Research Database (Denmark)

Samson, Alfred Junio; Hjalmarsson, Per; Søgaard, Martin

2012-01-01

An anode supported solid oxide fuel cell with an La0.6Sr0.4Co1.05O3_δ (LSC) infiltrated-Ce0.9Gd0.1O1.95 (CGO) cathode that shows a stable performance has been developed. The cathode was prepared by screen printing a porous CGO backbone on top of a laminated and co-fired anode supported half cell...... was tested at 700 deg. C under a current density of 0.5 A cm-2 for 1500 h using air as oxidant and humidified hydrogen as fuel. The electrochemical performance of the cell was analyzed by impedance spectroscopy and current evoltage relationships. No measurable degradation in the cell voltage or increase...... in the resistance from the recorded impedance was observed during long term testing. The power density reached 0.79Wcm-2 at a cell voltage of 0.6 V at 750 deg. C. Post test analysis of the LSC infiltrated-CGO cathode by scanning electron microscopy revealed no significant micro-structural difference...

Simplified fuel cell system model identification

Energy Technology Data Exchange (ETDEWEB)

Caux, S.; Fadel, M. [Laboratoire d' Electrotechnique et d' Electronique Industrielle, Toulouse (France); Hankache, W. [Laboratoire d' Electrotechnique et d' Electronique Industrielle, Toulouse (France)]|[Laboratoire de recherche en Electronique, Electrotechnique et Systemes, Belfort (France); Hissel, D. [Laboratoire de recherche en Electronique, Electrotechnique et Systemes, Belfort (France)

2006-07-01

This paper discussed a simplified physical fuel cell model used to study fuel cell and supercap energy applications for vehicles. Anode, cathode, membrane, and electrode elements of the cell were modelled. A quasi-static Amphlett model was used to predict voltage responses of the fuel cell as a function of the current, temperature, and partial pressures of the reactive gases. The potential of each cell was multiplied by the number of cells in order to model a fuel cell stack. The model was used to describe the main phenomena associated with current voltage behaviour. Data were then compared with data from laboratory tests conducted on a 20 cell stack subjected to a current and time profile developed using speed data from a vehicle operating in an urban environment. The validated model was used to develop iterative optimization algorithms for an energy management strategy that linked 3 voltage sources with fuel cell parameters. It was concluded that classic state and dynamic measurements using a simple least square algorithm can be used to identify the most important parameters for optimal fuel cell operation. 9 refs., 1 tab., 6 figs.

Water reactive hydrogen fuel cell power system

Science.gov (United States)

Wallace, Andrew P; Melack, John M; Lefenfeld, Michael

2014-01-21

A water reactive hydrogen fueled power system includes devices and methods to combine reactant fuel materials and aqueous solutions to generate hydrogen. The generated hydrogen is converted in a fuel cell to provide electricity. The water reactive hydrogen fueled power system includes a fuel cell, a water feed tray, and a fuel cartridge to generate power for portable power electronics. The removable fuel cartridge is encompassed by the water feed tray and fuel cell. The water feed tray is refillable with water by a user. The water is then transferred from the water feed tray into a fuel cartridge to generate hydrogen for the fuel cell which then produces power for the user.

Accelerated Degradation for Hardware in the Loop Simulation of Fuel Cell-Gas Turbine Hybrid System

DEFF Research Database (Denmark)

Abreu-Sepulveda, Maria A.; Harun, Nor Farida; Hackett, Gregory

2015-01-01

The U.S. Department of Energy (DOE)-National Energy Technology Laboratory (NETL) in Morgantown, WV has developed the hybrid performance (HyPer) project in which a solid oxide fuel cell (SOFC) one-dimensional (1D), real-time operating model is coupled to a gas turbine hardware system by utilizing...

Canadian fuel cell commercialization roadmap update : progress of Canada's hydrogen and fuel cell industry

International Nuclear Information System (INIS)

Filbee, S.; Karlsson, T.

2009-01-01

Hydrogen and fuel cells are considered an essential part of future low-carbon energy systems for transportation and stationary power. In recognition of this, Industry Canada has worked in partnership with public and private stakeholders to provide an update to the 2003 Canadian Fuel Cell Commercialization Roadmap to determine infrastructure requirements for near-term markets. The update includes technology and market developments in terms of cost and performance. This presentation included an overview of global hydrogen and fuel cell markets as background and context for the activities of the Canadian industry. Approaches toward commercial viability and mass market success were also discussed along with possible scenarios and processes by which these mass markets could develop. Hydrogen and fuel cell industry priorities were outlined along with recommendations for building a hydrogen infrastructure

Effect of in-pile degradation of the meat thermal conductivity on the maximum temperature of the plate-type U-Mo dispersion fuels

International Nuclear Information System (INIS)

Medvedev, Pavel G.

2009-01-01

Effect of in-pile degradation of thermal conductivity on the maximum temperature of the plate-type research reactor fuels has been assessed using the steady-state heat conduction equation and assuming convection cooling. It was found that due to very low meat thickness, characteristic for this type of fuel, the effect of thermal conductivity degradation on the maximum fuel temperature is minor. For example, the fuel plate featuring 0.635 mm thick meat operating at heat flux of 600 W/cm2 would experience only a 20 C temperature rise if the meat thermal conductivity degrades from 0.8 W/cm-s to 0.3 W/cm-s. While degradation of meat thermal conductivity in dispersion-type U-Mo fuel can be very substantial due to formation of interaction layer between the particles and the matrix, and development of fission gas filled porosity, this simple analysis demonstrates that this phenomenon is unlikely to significantly affect the temperature-based safety margin of the fuel during normal operation.

Response of a direct methanol fuel cell to fuel change

Energy Technology Data Exchange (ETDEWEB)

Leo, T.J. [Dpto de Sistemas Oceanicos y Navales- ETSI Navales, Univ. Politecnica de Madrid, Avda Arco de la Victoria s/n, 28040 Madrid (Spain); Raso, M.A.; de la Blanca, E. Sanchez [Dpto de Quimica Fisica I- Fac. CC. Quimicas, Univ. Complutense de Madrid, Avda Complutense s/n, 28040 Madrid (Spain); Navarro, E.; Villanueva, M. [Dpto de Motopropulsion y Termofluidodinamica, ETSI Aeronauticos, Univ. Politecnica de Madrid, Pza Cardenal Cisneros 3, 28040 Madrid (Spain); Moreno, B. [Instituto de Ceramica y Vidrio, Consejo Superior de Investigaciones Cientificas, C/Kelsen 5, Campus de la UAM, 28049 Cantoblanco, Madrid (Spain)

2010-10-15

Methanol and ethanol have recently received much attention as liquid fuels particularly as alternative 'energy-vectors' for the future. In this sense, to find a direct alcohol fuel cell that able to interchange the fuel without losing performances in an appreciable way would represent an evident advantage in the field of portable applications. In this work, the response of a in-house direct methanol fuel cell (DMFC) to the change of fuel from methanol to ethanol and its behaviour at different ambient temperature values have been investigated. A corrosion study on materials suitable to fabricate the bipolar plates has been carried out and either 316- or 2205-duplex stainless steels have proved to be adequate for using in direct alcohol fuel cells. Polarization curves have been measured at different ambient temperature values, controlled by an experimental setup devised for this purpose. Data have been fitted to a model taking into account the temperature effect. For both fuels, methanol and ethanol, a linear dependence of adjustable parameters with temperature is obtained. Fuel cell performance comparison in terms of open circuit voltage, kinetic and resistance is established. (author)

Direct methanol feed fuel cell and system

Science.gov (United States)

Surampudi, Subbarao (Inventor); Frank, Harvey A. (Inventor); Narayanan, Sekharipuram R. (Inventor); Chun, William (Inventor); Jeffries-Nakamura, Barbara (Inventor); Kindler, Andrew (Inventor); Halpert, Gerald (Inventor)

2009-01-01

Improvements to non acid methanol fuel cells include new formulations for materials. The platinum and ruthenium are more exactly mixed together. Different materials are substituted for these materials. The backing material for the fuel cell electrode is specially treated to improve its characteristics. A special sputtered electrode is formed which is extremely porous. The fuel cell system also comprises a fuel supplying part including a meter which meters an amount of fuel which is used by the fuel cell, and controls the supply of fuel based on said metering.

Aerosol feed direct methanol fuel cell

Science.gov (United States)

Kindler, Andrew (Inventor); Narayanan, Sekharipuram R. (Inventor); Valdez, Thomas I. (Inventor)

2002-01-01

Improvements to fuel cells include introduction of the fuel as an aerosol of liquid fuel droplets suspended in a gas. The particle size of the liquid fuel droplets may be controlled for optimal fuel cell performance by selection of different aerosol generators or by separating droplets based upon size using a particle size conditioner.

Performance Analysis and Development Strategies for Solid Oxide Fuel Cells

International Nuclear Information System (INIS)

Ivers-Tiffee, E; Leonide, A; Weber, A

2011-01-01

Solid oxide fuel cells (SOFC) are of great interest for a diverse range of applications. Within the past 10 years, an increase in power density by one order of magnitude, a lowering of the operating temperature by 200 K, and degradation rates lowered by a factor of 10 have been achieved on the cell and stack level. However, there is still room for further enhancement of the overall performance by suitably tailoring the cell components on a micro- and nanostructural level. The efficiency of the electrochemically active single cell is characterized by the linear ohmic losses within the electrolyte and by nonlinear polarization losses at the electrode-electrolyte interfaces. Both depend on material composition and operation conditions (temperature and time, fuel utilisation and gas composition). The area-specific resistance (ASR) is considered as the figure of merit for overall performance. ASR values of anode supported cells (ASC) were determined by means of impedance spectroscopy and subsequently separated into ohmic losses (mainly electrolyte) and nonlinear polarisation losses resulting from gas diffusion and activation polarization in the cathode and anode. The efficiencies of ASCs will be discussed for various material combinations in the temperature range of technological interest (between 550 deg. C and 850 deg. C).

Degradation of some ceria electrolytes under hydrogen contact nearby anode in solid oxide fuel cells (SOFCs

Directory of Open Access Journals (Sweden)

Malta Luiz Fernando Brum

2004-01-01

Full Text Available This work is concerned with thermodynamic analysis of the stability of some ceria electrolytes under contact with hydrogen gas nearby anode in fuel cells. It was considered the following types of ceria-electrolytes: pure ceria, strontium-doped ceria, calcium-doped ceria and calcium-bismuth-doped ceria. The equilibrium Log (pH2O/pH2 vs. T diagrams were constructed for x = 0.1 and 0.01, where x is the fraction of initial ceria converted to Ce2O3 (proportional to the ratio between activities of Ce3+ and Ce4+ in the ceria electrolyte, which is proportional to the fraction of electronic conduction in the electrolyte at a given temperature. The predictions of the diagrams are as follows: (a Ce1.9Ca0.1Bi0.8O5.1 and Ce0.9Sr0.1O1.9 are less stable than pure ceria for the whole temperature range (from 0 to 1000 °C; (b Ce0.9Ca0.1O1.9 is more stable than pure ceria below about 650 °C for x = 0.1 and below about 400 °C for x = 0.01; (c at each temperature in the considered range the pressure ratio pH2O(g/pH2(g has to be higher than thermodynamically predicted in order to keep CeO2 stable in the electrolyte contacting hydrogen gas. Thermodynamic predictions are entirely capable of explaining experimental data published on the subject (irreversible cell degradation in the case of SrO-doped ceria; weight loss from doped-ceria electrolyte above 700 °C; oxygen gas release during sintering of ceria.

1990 fuel cell seminar: Program and abstracts

Energy Technology Data Exchange (ETDEWEB)

1990-12-31

This volume contains author prepared short resumes of the presentations at the 1990 Fuel Cell Seminar held November 25-28, 1990 in Phoenix, Arizona. Contained herein are 134 short descriptions organized into topic areas entitled An Environmental Overview, Transportation Applications, Technology Advancements for Molten Carbonate Fuel Cells, Technology Advancements for Solid Fuel Cells, Component Technologies and Systems Analysis, Stationary Power Applications, Marine and Space Applications, Technology Advancements for Acid Type Fuel Cells, and Technology Advancement for Solid Oxide Fuel Cells.

Metrology for Fuel Cell Manufacturing

Energy Technology Data Exchange (ETDEWEB)

Stocker, Michael [National Inst. of Standards and Technology, Gaithersburg, MD (United States); Stanfield, Eric [National Inst. of Standards and Technology, Gaithersburg, MD (United States)

2015-02-04

The project was divided into three subprojects. The first subproject is Fuel Cell Manufacturing Variability and Its Impact on Performance. The objective was to determine if flow field channel dimensional variability has an impact on fuel cell performance. The second subproject is Non-contact Sensor Evaluation for Bipolar Plate Manufacturing Process Control and Smart Assembly of Fuel Cell Stacks. The objective was to enable cost reduction in the manufacture of fuel cell plates by providing a rapid non-contact measurement system for in-line process control. The third subproject is Optical Scatterfield Metrology for Online Catalyst Coating Inspection of PEM Soft Goods. The objective was to evaluate the suitability of Optical Scatterfield Microscopy as a viable measurement tool for in situ process control of catalyst coatings.

Platinum Porous Electrodes for Fuel Cells

DEFF Research Database (Denmark)

Andersen, Shuang Ma

Fuel cell energy bears the merits of renewability, cleanness and high efficiency. Proton Exchange Membrane Fuel Cell (PEMFC) is one of the most promising candidates as the power source in the near future. A fine management of different transports and electrochemical reactions in PEM fuel cells...... to a genuine picture of a working PEM fuel cell catalyst layer. These, in turn, enrich the knowledge of Three-Phase-Boundary, provide efficient tool for the electrode selection and eventually will contribute the advancement of PEMFC technology....

Open-source FCPEM-Performance & Durability Model Consideration of Membrane Properties on Cathode Degradation

Energy Technology Data Exchange (ETDEWEB)

Knights, Shanna [Ballard Fuel Cell Systems, Bend, OR (United States); Harvey, David [Ballard Fuel Cell Systems, Bend, OR (United States)

2017-01-20

The durability of PEM fuel cells is a primary requirement for large scale commercialization of these power systems in transportation and stationary market applications which target operational lifetimes of 5,000 hours and 60,000 hours by 2020, respectively. Key degradation modes contributing to fuel cell lifetime limitations have been largely associated with the platinum-based cathode catalyst layer. Furthermore, as fuel cells are driven to low cost materials and lower catalyst loadings in order to meet the cost targets for commercialization, the catalyst durability has become even more important. While over the past few years significant progress has been made in identifying the underlying causes of fuel cell degradation and key parameters that greatly influence the degradation rates, many gaps with respect to knowledge of the driving mechanisms still exist; in particular, the acceleration of the mechanisms due to different membrane compositions remains an area not well understood. The focus of this project extension was to enhance the predictive capability of the PEM Fuel Cell Performance & Durability Model called FC-APOLLO (Application Package for Open-source Long Life Operation) by including interaction effects of membrane transport properties such as water transport, changes in proton conductivity, and overall water uptake/adsorption and the state of the catalyst layer local conditions to further understand the driving forces for platinum dissolution.

Advances in catalysts for internal reforming in high temperature fuel cells

Science.gov (United States)

Dicks, A. L.

Catalytic steam reforming of natural gas is an attractive method of producing the hydrogen required by the present generation of fuel cells. The molten carbonate (MCFC) and solid oxide (SOFC) fuel cells operate at high enough temperatures for the endothermic steam reforming reaction to be carried out within the stack. For the MCFC, the conventional anodes have insufficient activity to catalyse the steam reforming of natural gas. For these cells, internal reforming can be achieved only with the addition of a separate catalyst, preferably located in close proximity to the anode. However, in the so-called `Direct Internal Reforming' configuration, attack from alkali in the MCFC may severely limit catalyst lifetime. In the case of the state-of-the-art SOFC, natural gas can be reformed directly on the nickel cermet anode. However, in the SOFC, temperature variations in the cell caused by the reforming reaction may limit the amount of internal reforming that can be allowed in practice. In addition, some external pre-reforming may be desirable to remove high molecular weight hydrocarbons from the fuel gas, which would otherwise crack to produce elemental carbon. Degradation of the SOFC anode may also be a problem when internal reforming is carried out. This has prompted several research groups to investigate the use of alternative anode materials.

Palliative effects of H2 on SOFCs operating with carbon containing fuels

Science.gov (United States)

Reeping, Kyle W.; Bohn, Jessie M.; Walker, Robert A.

2017-12-01

Chlorine can accelerate degradation of solid oxide fuel cell (SOFC) Ni-based anodes operating on carbon containing fuels through several different mechanisms. However, supplementing the fuel with a small percentage of excess molecular hydrogen effectively masks the degradation to the catalytic activity of the Ni and carbon fuel cracking reaction reactions. Experiments described in this work explore the chemistry behind the "palliative" effect of hydrogen on SOFCs operating with chlorine-contaminated, carbon-containing fuels using a suite of independent, complementary techniques. Operando Raman spectroscopy is used to monitor carbon accumulation and, by inference, Ni catalytic activity while electrochemical techniques including electrochemical impedance spectroscopy and voltammetry are used to monitor overall cell performance. Briefly, hydrogen not only completely hides degradation observed with chlorine-contaminated carbon-containing fuels, but also actively removes adsorbed chlorine from the surface of the Ni, allowing for the methane cracking reaction to continue, albeit at a slower rate. When hydrogen is removed from the fuel stream the cell fails immediately due to chlorine occupation of methane/biogas reaction sites.

Accelerated testing of fuel cell components in 2 x 2 inch fuel cells

International Nuclear Information System (INIS)

Coleman, A.J.; Adams, A.A.; Joebstl, J.A.; Walker, G.W.

1981-01-01

A description is presented of diagnostic procedures which can be used to predict failure modes and assess the effects of these failures on fuel cell performance. Some straightforward diagnostic techniques have been used to evaluate fuel cells assembled with a variety of matrix and electrode combinations. These techniques included accelerated on-off cycling, thermal cycling with H2/CO mixtures, and automatic polarization measurements. Information has been obtained concerning the effects of electrolyte management and catalyst poisoning on performance and lifetime characteristics of 2 x 2 in. single cells. The use of on-off cycling has shown that short-term fuel cell performance is generally unaffected by load changes and cycle sequence in 2 x 2 in. cells when electrolyte management is adequate. Dynamic polarization curves can be used instead of point by point steady-state plots without any loss in accuracy

World wide IFC phosphoric acid fuel cell implementation

Energy Technology Data Exchange (ETDEWEB)

King, J.M. Jr

1996-04-01

International Fuel Cells, a subsidary of United technologies Corporation, is engaged in research and development of all types of fuel cell technologies and currently manufactures alkaline fuel cell power plants for the U.S. manned space flight program and natural gas fueled stationary power plants using phosphoric acid fuel cells. This paper describes the phosphoric acid fuel cell power plants.

Stationary power fuel cell commercialization status worldwide

Energy Technology Data Exchange (ETDEWEB)

Williams, M.C. [Dept. of Energy, Morgantown, WV (United States)

1996-12-31

Fuel cell technologies for stationary power are set to play a role in power generation applications worldwide. The worldwide fuel cell vision is to provide powerplants for the emerging distributed generation and on-site markets. Progress towards commercialization has occurred in all fuel cell development areas. Around 100 ONSI phosphoric acid fuel cell (PAFC) units have been sold, with significant foreign sales in Europe and Japan. Fuji has apparently overcome its PAFC decay problems. Industry-driven molten carbonate fuel cell (MCFC) programs in Japan and the U.S. are conducting megawatt (MW)-class demonstrations, which are bringing the MCFC to the verge of commercialization. Westinghouse Electric, the acknowledged world leader in tubular solid oxide fuel cell (SOFC) technology, continues to set performance records and has completed construction of a 4-MW/year manufacturing facility in the U.S. Fuel cells have also taken a major step forward with the conceptual development of ultra-high efficiency fuel cell/gas turbine plants. Many SOFC developers in Japan, Europe, and North America continue to make significant advances.

Experimental study on the effect of cathode flow humidity and temperature on the performance of PEM fuel cell

Energy Technology Data Exchange (ETDEWEB)

El-Emam, R.S.; Awad, M.M.; Hamed, A.M.; Tolba, M. [Mansoura Univ., Mansoura (Egypt). Dept. of Mechanical Engineering

2009-07-01

The fuel cell is an electrochemical energy conversion device that produces electricity directly from chemical energy, and the by-products are only water and heat. The fuel cell could provide a solution to a whole range of environmental challenges, such as global warming and harmful levels of local pollutants. One of the most promising alternative power generation methods is the proton exchange membrane fuel cell (PEMFC) because of its low operating temperature, relative tolerance for impurities, and high power-density. This paper presented an experimental study on the performance characteristics of a single unit of a PEMFC with an active area of 25 square centimetres using two different cell configurations. The test system was designed to control the temperature and the relative humidity of the cathode feeding gas. Oxygen and air were used as oxidizers, while dry hydrogen was the cell fuel. Two different cell configurations were assembled and integrated into the test stand. The paper described the experimental work and presented the results of the study. It was concluded that low oxygen relative humidity with the dry hydrogen caused membrane drying and ultimately resulted in a degradation of fuel cell power output and cell performance. 17 refs., 17 figs.

Fuel Cell Seminar, 1992: Program and abstracts

Energy Technology Data Exchange (ETDEWEB)

1992-12-31

This year`s theme, ``Fuel Cells: Realizing the Potential,`` focuses on progress being made toward commercial manufacture and use of fuel cell products. Fuel cell power plants are competing for market share in some applications and demonstrations of market entry power plants are proceeding for additional applications. Development activity on fuel cells for transportation is also increasing; fuel cell products have potential in energy and transportation industries, with very favorable environmental impacts. This Seminar has the purpose of fostering communication by providing a forum for the international community interested in development, application, and business opportunities related fuel cells. Over 190 technical papers are included, the majority being processed for the data base.

Carbonate fuel cells: Milliwatts to megawatts

Science.gov (United States)

Farooque, M.; Maru, H. C.

The carbonate fuel cell power plant is an emerging high efficiency, ultra-clean power generator utilizing a variety of gaseous, liquid, and solid carbonaceous fuels for commercial and industrial applications. The primary mover of this generator is a carbonate fuel cell. The fuel cell uses alkali metal carbonate mixtures as electrolyte and operates at ∼650 °C. Corrosion of the cell hardware and stability of the ceramic components have been important design considerations in the early stages of development. The material and electrolyte choices are founded on extensive fundamental research carried out around the world in the 60s and early 70s. The cell components were developed in the late 1970s and early 1980s. The present day carbonate fuel cell construction employs commonly available stainless steels. The electrodes are based on nickel and well-established manufacturing processes. Manufacturing process development, scale-up, stack tests, and pilot system tests dominated throughout the 1990s. Commercial product development efforts began in late 1990s leading to prototype field tests beginning in the current decade leading to commercial customer applications. Cost reduction has been an integral part of the product effort. Cost-competitive product designs have evolved as a result. Approximately half a dozen teams around the world are pursuing carbonate fuel cell product development. The power plant development efforts to date have mainly focused on several hundred kW (submegawatt) to megawatt-class plants. Almost 40 submegawatt units have been operating at customer sites in the US, Europe, and Asia. Several of these units are operating on renewable bio-fuels. A 1 MW unit is operating on the digester gas from a municipal wastewater treatment plant in Seattle, Washington (US). Presently, there are a total of approximately 10 MW capacity carbonate fuel cell power plants installed around the world. Carbonate fuel cell products are also being developed to operate on

Elimination of pyraclostrobin by simultaneous microbial degradation coupled with the Fenton process in microbial fuel cells and the microbial community.

Science.gov (United States)

Zhao, Huanhuan; Kong, Chui-Hua

2018-06-01

The elimination of pyraclostrobin by simultaneous microbial degradation and Fenton oxidation was achieved in a microbial fuel cell (MFC) system. After 12 h of incubation, the removal rate of pyraclostrobin was 1.4 mg/L/h at the anode and 1.7 mg/L/h at the cathode. The pyraclostrobin concentration was less than the detection limit (0.1 mg/L) after 72 h at the anode and 24 h at the cathode. The air flow rate, temperature, and pH of the catholyte had significant effects on the generation of H 2 O 2 . The maximum production of H 2 O 2 was 1.2 mg/L after reaction for 20 h during the Fenton process. Microbial community analysis indicated that functional bacteria in the genera Chryseobacterium, Stenotrophomonas, Arcobacter, and Comamonas were predominant in the anodic biofilm. In conclusion, the MFC-Fenton system provides an effective approach for treating environmental contaminants. Copyright © 2018 Elsevier Ltd. All rights reserved.

Toward sustainable fuel cells

DEFF Research Database (Denmark)

Stephens, Ifan; Rossmeisl, Jan; Chorkendorff, Ib

2016-01-01

to a regular gasoline car. However, current fuel cells require 0.25 g of platinum (Pt) per kilowatt of power (2) as catalysts to drive the electrode reactions. If the entire global annual production of Pt were devoted to fuel cell vehicles, fewer than 10 million vehicles could be produced each year, a mere 10...

Fuel Cell and Battery Powered Forklifts

DEFF Research Database (Denmark)

Zhang, Zhe; Mortensen, Henrik H.; Jensen, Jes Vestervang

2013-01-01

A hydrogen-powered materials handling vehicle with a fuel cell combines the advantages of diesel/LPG and battery powered vehicles. Hydrogen provides the same consistent power and fast refueling capability as diesel and LPG, whilst fuel cells provide energy efficient and zero emission Electric...... propulsion similar to batteries. In this paper, the performance of a forklift powered by PEM fuel cells and lead acid batteries as auxiliary energy source is introduced and investigated. In this electromechanical propulsion system with hybrid energy/power sources, fuel cells will deliver average power...

Hydrogen as a fuel for fuel cell vehicles: A technical and economic comparison

Energy Technology Data Exchange (ETDEWEB)

Ogden, J.; Steinbugler, M.; Kreutz, T. [Princeton Univ., NJ (United States). Center for Energy and Environmental Studies

1997-12-31