Science.gov

Sample records for applications fuel cell

  1. Fuel processors for fuel cell APU applications

    NASA Astrophysics Data System (ADS)

    Aicher, T.; Lenz, B.; Gschnell, F.; Groos, U.; Federici, F.; Caprile, L.; Parodi, L.

    The conversion of liquid hydrocarbons to a hydrogen rich product gas is a central process step in fuel processors for auxiliary power units (APUs) for vehicles of all kinds. The selection of the reforming process depends on the fuel and the type of the fuel cell. For vehicle power trains, liquid hydrocarbons like gasoline, kerosene, and diesel are utilized and, therefore, they will also be the fuel for the respective APU systems. The fuel cells commonly envisioned for mobile APU applications are molten carbonate fuel cells (MCFC), solid oxide fuel cells (SOFC), and proton exchange membrane fuel cells (PEMFC). Since high-temperature fuel cells, e.g. MCFCs or SOFCs, can be supplied with a feed gas that contains carbon monoxide (CO) their fuel processor does not require reactors for CO reduction and removal. For PEMFCs on the other hand, CO concentrations in the feed gas must not exceed 50 ppm, better 20 ppm, which requires additional reactors downstream of the reforming reactor. This paper gives an overview of the current state of the fuel processor development for APU applications and APU system developments. Furthermore, it will present the latest developments at Fraunhofer ISE regarding fuel processors for high-temperature fuel cell APU systems on board of ships and aircrafts.

  2. Alkaline fuel cells applications

    NASA Astrophysics Data System (ADS)

    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.

  3. Chitosan biopolymer for fuel cell applications.

    PubMed

    Ma, Jia; Sahai, Yogeshwar

    2013-02-15

    Fuel cell is an electrochemical device which converts chemical energy stored in a fuel into electrical energy. Fuel cells have been receiving attention due to its potential applicability as a good alternative power source. Recently, cost-effective and eco-friendly biopolymer chitosan has been extensively studied as a material for membrane electrolytes and electrodes in low to intermediate temperature hydrogen polymer electrolyte fuel cell, direct methanol fuel cell, alkaline fuel cell, and biofuel cell. This paper reviews structure and property of chitosan with respect to its applications in fuel cells. Recent achievements and prospect of its applications have also been included.

  4. Fuel cells for extraterrestrial and terrestrial applications

    NASA Astrophysics Data System (ADS)

    Srinivasan, S.

    The fuel cell is a nineteenth century invention and a twentieth century technology development. Due to the high power and energy density, high efficiency, reliability, and production of pure water, hydrogen-oxygen fuel cell systems have no competition as auxiliary power sources for space vehicles. The alkaline fuel cell system is a well developed and proven technology for this application. The solid polymer electrolyte system may be its future competitor. The energy crisis of 1973 stimulated research, development and demonstration of the phosphoric acid, molten carbonate, solid oxide and solid polymer electrolyte fuel cell systems using natural gas, petroleum or coal derived hydrogen (and carbon monoxide for the high temperature systems) for terrestrial applications. The direct methanol-air fuel cell is still an electrochemist's dream. Though considerable technological advances have been made, the present price of crude oil, and the high capital costs and limited lifetime of fuel cell systems impede their terrestrial applications in the developed countries. Conversely, the potential for lower capital costs of labor intensive manufacturing processes and the relatively higher fossil fuel prices make these systems more attractive for such applications in the developing countries.

  5. Fuel cells for extraterrestrial and terrestrial applications

    SciTech Connect

    Srinivasan, S.

    1987-01-01

    The fuel cell is a nineteenth century invention and a twentieth century technology development. Due to the high power and energy density, high efficiency, reliability, and production of pure water, hydrogen-oxygen fuel cell systems have no competition as auxiliary power sources for space vehicles. The alkaline fuel cell system is a well developed and proven technology for this application. The solid polymer electrolyte system may be its future competitor. The energy crisis of 1973 stimulated research, development and demonstration of the phosphoric acid, molten carbonate, solid oxide and solid polymer electrolyte fuel cell systems using natural gas, petroleum or coal derived hydrogen (and carbon monoxide for the high temperature systems) for terrestrial applications. The direct methanol-air fuel cell is still an electrochemist's dream. Though considerable technological advances have been made, the present price of crude oil, and the high capital costs and limited lifetime of fuel cell systems impede their terrestrial applications in the developed countries. Conversely, the potential for lower capital costs of labor intensive manufacturing processes and the relatively higher fossil fuel prices make these systems more attractive for such applications in the developing countries. 11 refs.

  6. Fuel cells for low power applications

    NASA Astrophysics Data System (ADS)

    Heinzel, A.; Hebling, C.; Müller, M.; Zedda, M.; Müller, C.

    Electronic devices show an ever-increasing power demand and thus, require innovative concepts for power supply. For a wide range of power and energy capacity, membrane fuel cells are an attractive alternative to conventional batteries. The main advantages are the flexibility with respect to power and capacity achievable with different devices for energy conversion and energy storage, the long lifetime and long service life, the good ecological balance, very low self-discharge. Therefore, the development of fuel cell systems for portable electronic devices is an attractive, although also a challenging, goal. The fuel for a membrane fuel cell might be hydrogen from a hydride storage system or methanol/water as a liquid alternative. The main differences between the two systems are the much higher power density for hydrogen fuel cells, the higher energy density per weight for the liquid fuel, safety aspects and infrastructure for fuel supply for hydride materials. For different applications, different system designs are required. High power cells are required for portable computers, low power methanol fuel cells required for mobile phones in hybrid systems with batteries and micro-fuel cells are required, e.g. for hand held PCs in the sub-Watt range. All these technologies are currently under development. Performance data and results of simulations and experimental investigations will be presented.

  7. Gasifiers optimized for fuel cell applications

    NASA Astrophysics Data System (ADS)

    Steinfeld, G.; Fruchtman, J.; Hauserman, W. B.; Lee, A.; Meyers, S. J.

    Conventional coal gasification carbonate fuel cell systems are typically configured so that the fuel gas is primarily hydrogen, carbon monoxide, and carbon dioxide, with waste heat recovery for process requirements and to produce additional power in a steam bottoming cycle. These systems make use of present day gasification processes to produce the low to medium Btu fuel gas which in turn is cleaned up and consumed by the fuel cell. These conventional gasification/fuel cell systems have been studied in recent years projecting system efficiencies of 45-53 percent (HHV). Conventional gasification systems currently available evolved as stand-alone systems producing low to medium Btu gas fuel gas. The requirements of the gasification process dictates high temperatures to carry out the steam/carbon reaction and to gasify the tars present in coal. The high gasification temperatures required are achieved by an oxidant which consumes a portion of the feed coal to provide the endothermic heat required for the gasification process. The thermal needs of this process result in fuel gas temperatures that are higher than necessary for most end use applications, as well as for gas cleanup purposes. This results in some efficiency and cost penalties. This effort is designed to study advanced means of power generation by integrating the gasification process with the unique operating characteristics of carbonate fuel cells to achieve a more efficient and cost effective coal based power generating system. This is to be done by altering the gasification process to produce fuel gas compositions which result in more efficient fuel cell operation and by integrating the gasification process with the fuel cell as shown in Figure 2. Low temperature catalytic gasification was chosen as the basis for this effort due to the inherent efficiency advantages and compatibility with fuel cell operating temperatures.

  8. New applications for phosphoric acid fuel cells

    NASA Technical Reports Server (NTRS)

    Stickles, R. P.; Breuer, C. T.

    1983-01-01

    New applications for phosphoric acid fuel cells were identified and evaluated. Candidates considered included all possibilities except grid connected electric utility applications, on site total energy systems, industrial cogeneration, opportunistic use of waste hydrogen, space and military applications, and applications smaller than 10 kW. Applications identified were screened, with the most promising subjected to technical and economic evaluation using a fuel cell and conventional power system data base developed in the study. The most promising applications appear to be the underground mine locomotive and the railroad locomotive. Also interesting are power for robotic submersibles and Arctic villages. The mine locomotive is particularly attractive since it is expected that the fuel cell could command a very high price and still be competitive with the conventionally used battery system. The railroad locomotive's attractiveness results from the (smaller) premium price which the fuel cell could command over the conventional diesel electric system based on its superior fuel efficiency, and on the large size of this market and the accompanying opportunities for manufacturing economy.

  9. New applications for phosphoric acid fuel cells

    SciTech Connect

    Stickles, R.P.; Breuer, C.T.

    1983-11-01

    New applications for phosphoric acid fuel cells were identified and evaluated. Candidates considered included all possibilities except grid connected electric utility applications, on-site total energy systems, industrial co-generation, opportunistic use of waste hydrogen, space and military applications, and applications smaller than 10 kW. Applications identified were screened, with the most promising subjected to technical and economic evaluation using a fuel cell and conventional power system data base developed in the study. The most promising applications appear to be the underground mine locomotive and the railroad locomotive. Also interesting is power for robotic submersibles and Arctic villages. The mine locomotive is particularly attractive since it is expected that the fuel cell could command a very high price and still be competitive with the conventionally used battery system. The railroad locomotive's attractiveness results from the (smaller) premium price which the fuel cell could command over the conventional diesel electric system based on its superior fuel efficiency, and on the large size of this market and the accompanying opportunities for manufacturing economy.

  10. Fuel Cells Today: Early Market Applications and Learning Demonstrations

    SciTech Connect

    2015-09-09

    This MP3 provides an overview of early market fuel cell applications including today's commercially available fuel cells and "learning demonstrations" to validate fuel cell technology in real world conditions.

  11. Applicability of molten carbonate fuel cells to various fuels

    NASA Astrophysics Data System (ADS)

    Watanabe, Takao; Izaki, Yoshiyuki; Mugikura, Yoshihiro; Morita, Hiroshi; Yoshikawa, Masahiro; Kawase, Makoto; Yoshiba, Fumihiko; Asano, Koichi

    MCFCs can utilize CO rich and H 2 lean fuel, such as gasified biomass or gasified waste as a Pt catalyst is not used and Pt poisoning by CO does not occur. This feature has become very important due to the worldwide CO 2 depression requirements. CRIEPI has developed MCFC technologies in line with a governmental program, which mainly focused on natural gas fuel. However, CRIEPI has recently been focussing on technologies for various fuel applications. Single cells and stacks were tested with various gas compositions and showed stable performance even with high CO and high fuel utilization conditions. Gasified biomass or waste can contain many kinds of impurities such as H 2S, HCl, HF, NH 3, etc. The effects of these impurities were taken into account for single cells, and the permissible limits were estimated.

  12. Miniaturized biological and electrochemical fuel cells: challenges and applications.

    PubMed

    Yang, Jie; Ghobadian, Sasan; Goodrich, Payton J; Montazami, Reza; Hashemi, Nastaran

    2013-09-14

    This paper discusses the fundamentals and developments of miniaturized fuel cells, both biological and electrochemical. An overview of microfluidic fuel cells, miniaturized microbial fuel cells, enzymatic biofuel cells, and implanted biofuel cells in an attempt to provide green energy and to power implanted microdevices is provided. Also, the challenges and applications of each type of fuel cell are discussed in detail. Most recent developments in fuel cell technologies such as novel catalysts, compact designs, and fabrication methods are reviewed.

  13. Fuel cell system for transportation applications

    DOEpatents

    Kumar, R.; Ahmed, S.; Krumpelt, M.; Myles, K.M.

    1993-09-28

    A propulsion system is described for a vehicle having pairs of front and rear wheels and a fuel tank. An electrically driven motor having an output shaft operatively connected to at least one of said pair of wheels is connected to a fuel cell having a positive electrode and a negative electrode separated by an electrolyte for producing dc power to operate the motor. A partial oxidation reformer is connected both to the fuel tank and to the fuel cell and receives hydrogen-containing fuel from the fuel tank and uses water and air for partially oxidizing and reforming the fuel in the presence of an oxidizing catalyst and a reforming catalyst to produce a hydrogen-containing gas. The hydrogen-containing gas is sent from the partial oxidation reformer to the fuel cell negative electrode while air is transported to the fuel cell positive electrode to produce dc power for operating the electric motor. 3 figures.

  14. Fuel cell system for transportation applications

    DOEpatents

    Kumar, Romesh; Ahmed, Shabbir; Krumpelt, Michael; Myles, Kevin M.

    1993-01-01

    A propulsion system for a vehicle having pairs of front and rear wheels and a fuel tank. An electrically driven motor having an output shaft operatively connected to at least one of said pair of wheels is connected to a fuel cell having a positive electrode and a negative electrode separated by an electrolyte for producing dc power to operate the motor. A partial oxidation reformer is connected both to the fuel tank and to the fuel cell receives hydrogen-containing fuel from the fuel tank and water and air and for partially oxidizing and reforming the fuel with water and air in the presence of an oxidizing catalyst and a reforming catalyst to produce a hydrogen-containing gas. The hydrogen-containing gas is sent from the partial oxidation reformer to the fuel cell negative electrode while air is transported to the fuel cell positive electrode to produce dc power for operating the electric motor.

  15. Yeast fuel cell: Application for desalination

    NASA Astrophysics Data System (ADS)

    Mardiana, Ummy; Innocent, Christophe; Cretin, Marc; Buchari, Buchari; Gandasasmita, Suryo

    2016-02-01

    Yeasts have been implicated in microbial fuel cells as biocatalysts because they are non-pathogenic organisms, easily handled and robust with a good tolerance in different environmental conditions. Here we investigated baker's yeast Saccharomyces cerevisiae through the oxidation of glucose. Yeast was used in the anolyte, to transfer electrons to the anode in the presence of methylene blue as mediator whereas K3Fe(CN)6 was used as an electron acceptor for the reduction reaction in the catholyte. Power production with biofuel cell was coupled with a desalination process. The maximum current density produced by the cell was 88 mA.m-2. In those conditions, it was found that concentration of salt was removed 64% from initial 0.6 M after 1-month operation. This result proves that yeast fuel cells can be used to remove salt through electrically driven membrane processes and demonstrated that could be applied for energy production and desalination. Further developments are in progress to improve power output to make yeast fuel cells applicable for water treatment.

  16. Fuel Cells for Space Science Applications

    NASA Technical Reports Server (NTRS)

    Burke, Kenneth A.

    2003-01-01

    Fuel cell technology has been receiving more attention recently as a possible alternative to the internal combustion engine for our automobile. Improvements in fuel cell designs as well as improvements in lightweight high-pressure gas storage tank technology make fuel cell technology worth a look to see if fuel cells can play a more expanded role in space missions. This study looks at the specific weight density and specific volume density of potential fuel cell systems as an alternative to primary and secondary batteries that have traditionally been used for space missions. This preliminary study indicates that fuel cell systems have the potential for energy densities of greater than 500 W-hr/kg, greater than 500W/kg and greater than 400 W-hr/liter, greater than 200 W/liter. This level of performance makes fuel cells attractive as high-power density, high-energy density sources for space science probes, planetary rovers and other payloads. The power requirements for these space missions are, in general, much lower than the power levels where fuel cells have been used in the past. Adaptation of fuel cells for space science missions will require down-sizing the fuel cell stack and making the fuel cell operate without significant amounts of ancillary equipment.

  17. Sodium Borohydride/Hydrogen Peroxide Fuel Cells For Space Application

    NASA Technical Reports Server (NTRS)

    Valdez, T. I.; Deelo, M. E.; Narayanan, S. R.

    2006-01-01

    This viewgraph presentation examines Sodium Borohydride and Hydrogen Peroxide Fuel Cells as they are applied to space applications. The topics include: 1) Motivation; 2) The Sodium Borohydride Fuel Cell; 3) Sodium Borohydride Fuel Cell Test Stands; 4) Fuel Cell Comparisons; 5) MEA Performance; 6) Anode Polarization; and 7) Electrode Analysis. The benefits of hydrogen peroxide as an oxidant and benefits of sodium borohydride as a fuel are also addressed.

  18. Microbial fuel cells for biosensor applications.

    PubMed

    Yang, Huijia; Zhou, Minghua; Liu, Mengmeng; Yang, Weilu; Gu, Tingyue

    2015-12-01

    Microbial fuel cells (MFCs) face major hurdles for real-world applications as power generators with the exception of powering small sensor devices. Despite tremendous improvements made in the last two decades, MFCs are still too expensive to build and operate and their power output is still too small. In view of this, in recently years, intensive researches have been carried out to expand the applications into other areas such as acid and alkali production, bioremediation of aquatic sediments, desalination and biosensors. Unlike power applications, MFC sensors have the immediate prospect to be practical. This review covers the latest developments in various proposed biosensor applications using MFCs including monitoring microbial activity, testing biochemical oxygen demand, detection of toxicants and detection of microbial biofilms that cause biocorrosion.

  19. Fuel cell systems for personal and portable power applications

    SciTech Connect

    Fateen, S. A.

    2001-01-01

    Fuel cells are devices that electrochemically convert fuel, usually hydrogen gas, to directly produce electricity. Fuel cells were initially developed for use in the space program to provide electricity and drinking water for astronauts. Fuel cells are under development for use in the automobile industry to power cars and buses with the advantage of lower emissions and higher efficiency than internal combustion engines. Fuel cells also have great potential to be used in portable consumer products like cellular phones and laptop computers, as well as military applications. In fact, any products that use batteries can be powered by fuel cells. In this project, we examine fuel cell system trade-offs between fuel cell type and energy storage/hydrogen production for portable power generation. The types of fuel cells being examined include stored hydrogen PEM (polymer electrolyte), direct methanol fuel cells (DMFC) and indirect methanol fuel cells, where methanol is reformed producing hydrogen. These fuel cells systems can operate at or near ambient conditions, which make them potentially optimal for use in manned personal power applications. The expected power production for these systems is in the range of milliwatts to 500 watts of electrical power for either personal or soldier field use. The fuel cell system trade-offs examine hydrogen storage by metal hydrides, carbon nanotubes, and compressed hydrogen tanks. We examine the weights each system, volume, fuel storage, system costs, system peripherals, power output, and fuel cell feasibility in portable devices.

  20. Fuel cells 101

    SciTech Connect

    Hirschenhofer, J.H.

    1999-07-01

    This paper discusses the various types of fuel cells, the importance of cell voltage, fuel processing for natural gas, cell stacking, fuel cell plant description, advantages and disadvantages of the types of fuel cells, and applications. The types covered include: polymer electrolyte fuel cell, alkaline fuel cell, phosphoric acid fuel cell; molten carbonate fuel cell, and solid oxide fuel cell.

  1. Reduced size fuel cell for portable applications

    NASA Technical Reports Server (NTRS)

    Narayanan, Sekharipuram R. (Inventor); Valdez, Thomas I. (Inventor); Clara, Filiberto (Inventor); Frank, Harvey A. (Inventor)

    2004-01-01

    A flat pack type fuel cell includes a plurality of membrane electrode assemblies. Each membrane electrode assembly is formed of an anode, an electrolyte, and an cathode with appropriate catalysts thereon. The anode is directly into contact with fuel via a wicking element. The fuel reservoir may extend along the same axis as the membrane electrode assemblies, so that fuel can be applied to each of the anodes. Each of the fuel cell elements is interconnected together to provide the voltage outputs in series.

  2. PEM fuel cell applications and their development at International Fuel Cells

    SciTech Connect

    Fuller, T.F.; Gorman, M.E.; Van Dine, L.L.

    1996-12-31

    International Fuel Cells (IFC) is involved with the full spectrum of fuel cell power plants including the development of Proton Exchange Membrane (PEM) fuel cell systems. The extensive background in systems, design, materials and manufacturing technologies has been brought to bear on the development of highly competitive PEM power plants. IFC is aggressively pursuing these opportunities and is developing low-cost designs for a wide variety of PEM fuel cell applications with special emphasis on portable power and transportation. Experimental PEM power plants for each of these applications have been successfully tested.

  3. LANDFILL GAS PRETREATMENT FOR FUEL CELL APPLICATIONS

    EPA Science Inventory

    The paper discusses the U.S. EPA's program, underway at International Fuel Cells Corporation, to demonstrate landfill methane control and the fuel cell energy recovery concept. In this program, two critical issues are being addressed: (1) a landfill gas cleanup method that would ...

  4. A review of fuel cell systems for maritime applications

    NASA Astrophysics Data System (ADS)

    van Biert, L.; Godjevac, M.; Visser, K.; Aravind, P. V.

    2016-09-01

    Progressing limits on pollutant emissions oblige ship owners to reduce the environmental impact of their operations. Fuel cells may provide a suitable solution, since they are fuel efficient while they emit few hazardous compounds. Various choices can be made with regard to the type of fuel cell system and logistic fuel, and it is unclear which have the best prospects for maritime application. An overview of fuel cell types and fuel processing equipment is presented, and maritime fuel cell application is reviewed with regard to efficiency, gravimetric and volumetric density, dynamic behaviour, environmental impact, safety and economics. It is shown that low temperature fuel cells using liquefied hydrogen provide a compact solution for ships with a refuelling interval up to a tens of hours, but may result in total system sizes up to five times larger than high temperature fuel cells and more energy dense fuels for vessels with longer mission requirements. The expanding infrastructure of liquefied natural gas and development state of natural gas-fuelled fuel cell systems can facilitate the introduction of gaseous fuels and fuel cells on ships. Fuel cell combined cycles, hybridisation with auxiliary electricity storage systems and redundancy improvements are identified as topics for further study.

  5. US Department of Energy fuel cell program for transportation applications

    NASA Astrophysics Data System (ADS)

    Patil, Pandit G.

    1992-01-01

    Fuel cells of offer promise as the best future replacement for internal combustion engines in transportation applications. Fuel cells operate more efficiently than internal combustion engines, and are capable of running on non-petroleum fuels such as methanol, ethanol, natural gas or hydrogen. Fuel cells can also have a major impact on improving air quality. They virtually eliminate particulates, NO(x) and sulfur oxide emissions, and significantly reduce hydrocarbons and carbon monoxide. The U.S. Department of Energy program on fuel cells for transportation applications is structured to advance fuel cells technologies from the R&D phase, through engineering design and scale-tip, to demonstration in cars, trucks, buses and locomotives, in order to provide energy savings, fuel flexibility and air quality improvements. This paper describes the present status of the U.S. program.

  6. Fuel cells

    NASA Astrophysics Data System (ADS)

    1984-12-01

    The US Department of Energy (DOE), Office of Fossil Energy, has supported and managed a fuel cell research and development (R and D) program since 1976. Responsibility for implementing DOE's fuel cell program, which includes activities related to both fuel cells and fuel cell systems, has been assigned to the Morgantown Energy Technology Center (METC) in Morgantown, West Virginia. The total United States effort of the private and public sectors in developing fuel cell technology is referred to as the National Fuel Cell Program (NFCP). The goal of the NFCP is to develop fuel cell power plants for base-load and dispersed electric utility systems, industrial cogeneration, and on-site applications. To achieve this goal, the fuel cell developers, electric and gas utilities, research institutes, and Government agencies are working together. Four organized groups are coordinating the diversified activities of the NFCP. The status of the overall program is reviewed in detail.

  7. Removal of sulfur contaminants in methanol for fuel cell applications

    SciTech Connect

    Lee, S.H.D.; Kumar, R.; Sederquist, R.

    1996-12-31

    Fuel cell power plants are being developed for transit bus and passenger car applications that use methanol as the on-board fuel. Commodity methanol by itself contains very little sulfur; however, it may occasionally be contaminated with up to about 1% diesel fuel or gasoline in current liquid-fuel distribution systems, leading to the presence of sulfur in the methanol fuel. This sulfur must be removed because of its deleterious effect on the reforming catalysts. International Fuel Cells has set the allowable sulfur limit in the methanol fuel at less than 1 ppm. The equilibrium adsorption isotherm and breakthrough data were used to assess the feasibility of developing a granular activated carbon adsorber for the removal of sulfur from transportation fuel cell systems.

  8. On direct and indirect methanol fuel cells for transportation applications

    SciTech Connect

    Gottesfield, S.

    1996-04-01

    Research on direct oxidation methanol fuel cells (DMFCs) and polymer electrolyte fuel cells (PEFCs) is discussed. Systems considered for transportation applications are addressed. The use of platinum/ruthenium anode electrocatalysts and platinum cathode electrocatalysts in polymer electrolyte DMFCs has resulted in significant performance enhancements.

  9. Proton exchange membrane fuel cell technology for transportation applications

    SciTech Connect

    Swathirajan, S.

    1996-04-01

    Proton Exchange Membrane (PEM) fuel cells are extremely promising as future power plants in the transportation sector to achieve an increase in energy efficiency and eliminate environmental pollution due to vehicles. GM is currently involved in a multiphase program with the US Department of Energy for developing a proof-of-concept hybrid vehicle based on a PEM fuel cell power plant and a methanol fuel processor. Other participants in the program are Los Alamos National Labs, Dow Chemical Co., Ballard Power Systems and DuPont Co., In the just completed phase 1 of the program, a 10 kW PEM fuel cell power plant was built and tested to demonstrate the feasibility of integrating a methanol fuel processor with a PEM fuel cell stack. However, the fuel cell power plant must overcome stiff technical and economic challenges before it can be commercialized for light duty vehicle applications. Progress achieved in phase I on the use of monolithic catalyst reactors in the fuel processor, managing CO impurity in the fuel cell stack, low-cost electrode-membrane assembles, and on the integration of the fuel processor with a Ballard PEM fuel cell stack will be presented.

  10. Fuel cell added value for early market applications

    NASA Astrophysics Data System (ADS)

    Hardman, Scott; Chandan, Amrit; Steinberger-Wilckens, Robert

    2015-08-01

    Fuel Cells are often considered in the market place as just power providers. Whilst fuel cells do provide power, there are additional beneficial characteristics that should be highlighted to consumers. Due to the high price premiums associated with fuel cells, added value features need to be exploited in order to make them more appealing and increase unit sales and market penetration. This paper looks at the approach taken by two companies to sell high value fuel cells to niche markets. The first, SFC Energy, has a proven track record selling fuel cell power providers. The second, Bloom Energy, is making significant progress in the US by having sold its Energy Server to more than 40 corporations including Wal-Mart, Staples, Google, eBay and Apple. Further to these current markets, two prospective added value applications for fuel cells are discussed. These are fuel cells for aircraft APUs and fuel cells for fire prevention. These two existing markets and two future markets highlight that fuel cells are not just power providers. Rather, they can be used as solutions to many needs, thus being more cost effective by replacing a number of incumbent systems at the same time.

  11. Microbial fuel cells: Their application and microbiology

    NASA Astrophysics Data System (ADS)

    He, Zhen

    The energy crisis is an urgent global issue due to the increased consumption of the finite amount of fossil fuel. As a result, looking for alternative energy sources is of critical importance. Microbial fuel cell (MFC) technology can extract electric energy from wastewater, and thus is a sustainable approach to supply energy to our electricity-based society. My research focuses on the development of a suitable MFC reactor for wastewater treatment and the understanding of the microbial function in the MFC process. First, together with colleagues, I have developed a novel MFC reactor, named upflow microbial fuel cell (UMFC), by combining upflow and MFC technologies. The power output from the UMFC was improved by 10-fold after it was modified with a U-shape cathode. The UMFC appears to be a practical reactor for continuous operation, though the output of electric power requires further improvement. In addition, a sediment MFC with a rotating cathode was also developed and its performance was examined. Second, I have adopted a human distal gut anaerobe, Bacteroides thetaiotaomicron, as the model organism to study the role of fermentative bacterium in electricity generation. When B. thetaiotaomicron grew under an applied electric potential, an electric current was generated. GeneChip data indicated that this bacterium did not alter its metabolism during this process. Although B. thetaiotaomicron may not be capable of respiration with an electrode as the electron acceptor, the experiment has demonstrated that fermentative bacteria may play an important role in electricity generation.

  12. SPE (tm) regenerative hydrogen/oxygen fuel cells for extraterrestrial surface and microgravity applications

    NASA Technical Reports Server (NTRS)

    Mcelroy, J. F.

    1990-01-01

    Viewgraphs on SPE regenerative hydrogen/oxygen fuel cells for extraterrestrial surface and microgravity applications are presented. Topics covered include: hydrogen-oxygen regenerative fuel cell energy storage system; electrochemical cell reactions; SPE cell voltage stability; passive water removal SPE fuel cell; fuel cell performance; SPE water electrolyzers; hydrophobic oxygen phase separator; hydrophilic/electrochemical hydrogen phase separator; and unitized regenerative fuel cell.

  13. Application of Vacuum Deposition Methods to Solid Oxide Fuel Cells

    SciTech Connect

    Pederson, Larry R.; Singh, Prabhakar; Zhou, Xiao Dong

    2006-07-01

    The application of vacuum deposition techniques to the fabrication of solid oxide fuel cell materials and structures are reviewed, focusing on magnetron sputtering, vacuum plasma methods, laser ablation, and electrochemical vapor deposition. A description of each method and examples of use to produce electrolyte, electrode, and/or electrical interconnects are given. Generally high equipment costs and relatively low deposition rates have limited the use of vacuum deposition methods in solid oxide fuel cell manufacture, with a few notable exceptions. Vacuum methods are particularly promising in the fabrication of micro fuel cells, where thin films of high quality and unusual configuration are desired.

  14. Proton Exchange Membrane (PEM) Fuel Cells for Space Applications

    NASA Technical Reports Server (NTRS)

    Bradley, Karla

    2004-01-01

    This presentation will provide a summary of the PEM fuel cell development at the National Aeronautics and Space Administration, Johnson Space Center (NASA, JSC) in support of future space applications. Fuel cells have been used for space power generation due to their high energy storage density for multi-day missions. The Shuttle currently utilizes the alkaline fuel cell technology, which has highly safe and reliable performance. However, the alkaline technology has a limited life due to the corrosion inherent to the alkaline technology. PEM fuel cells are under development by industry for transportation, residential and commercial stationary power applications. NASA is trying to incorporate some of this stack technology development in the PEM fuel cells for space. NASA has some unique design and performance parameters which make developing a PEM fuel cell system more challenging. Space fuel cell applications utilize oxygen, rather than air, which yields better performance but increases the hazard level. To reduce the quantity of reactants that need to be flown in space, NASA also utilizes water separation and reactant recirculation. Due to the hazards of utilizing active components for recirculation and water separation, NASA is trying to develop passive recirculation and water separation methods. However, the ability to develop recirculation components and water separators that are gravity-independent and successfully operate over the full range of power levels is one of the greatest challenges to developing a safe and reliable PEM fuel cell system. PEM stack, accessory component, and system tests that have been performed for space power applications will be discussed.

  15. Assessment of bio-fuel options for solid oxide fuel cell applications

    NASA Astrophysics Data System (ADS)

    Lin, Jiefeng

    Rising concerns of inadequate petroleum supply, volatile crude oil price, and adverse environmental impacts from using fossil fuels have spurred the United States to promote bio-fuel domestic production and develop advanced energy systems such as fuel cells. The present dissertation analyzed the bio-fuel applications in a solid oxide fuel cell-based auxiliary power unit from environmental, economic, and technological perspectives. Life cycle assessment integrated with thermodynamics was applied to evaluate the environmental impacts (e.g., greenhouse gas emission, fossil energy consumption) of producing bio-fuels from waste biomass. Landfill gas from municipal solid wastes and biodiesel from waste cooking oil are both suggested as the promising bio-fuel options. A nonlinear optimization model was developed with a multi-objective optimization technique to analyze the economic aspect of biodiesel-ethanol-diesel ternary blends used in transportation sectors and capture the dynamic variables affecting bio-fuel productions and applications (e.g., market disturbances, bio-fuel tax credit, policy changes, fuel specification, and technological innovation). A single-tube catalytic reformer with rhodium/ceria-zirconia catalyst was used for autothermal reformation of various heavy hydrocarbon fuels (e.g., diesel, biodiesel, biodiesel-diesel, and biodiesel-ethanol-diesel) to produce a hydrogen-rich stream reformates suitable for use in solid oxide fuel cell systems. A customized mixing chamber was designed and integrated with the reformer to overcome the technical challenges of heavy hydrocarbon reformation. A thermodynamic analysis, based on total Gibbs free energy minimization, was implemented to optimize the operating environment for the reformations of various fuels. This was complimented by experimental investigations of fuel autothermal reformation. 25% biodiesel blended with 10% ethanol and 65% diesel was determined to be viable fuel for use on a truck travelling with

  16. Fuel cells for electric utility and transportation applications

    NASA Astrophysics Data System (ADS)

    Srinivasan, S.

    1980-04-01

    The status of fuel cell development is reviewed. For terrestrial electric utility applications, the most promising are phosphoric acid, molten carbonate and solid electrolyte fuel cells. The first will be coupled with a reformer (to convert natural gas, petroleum derived and biomass fuels to hydrogen) while the second and third with a coal gasifier. As ground transportation power sources, the promising systems are phosphoric (or alternate acid) and alkaline electrolyte fuel cells. In the first case, methanol is most attractive while in the second, it will be hydrogen stored as a compressed gas or as a hydride. A technoeconomic assessment of a 'Regenerative Hydrogen-Halogen Energy Storage System' demonstrates the prospects of its use for load leveling when coupled with nuclear, solar or wind power plants.

  17. Ceramic fuel cells for stationary and mobile applications

    SciTech Connect

    Singhal, Subhash C. )

    2003-11-01

    Fuel cells are newsworthy because of high gasoline prices and concern about the environment. Several questions arise when fuel cells are discussed: - What are fuel cells? - What is the current status of fuel cells? - What fuel cell designs are being pursued by various organizations worldwide? - What are the advantages and disadvantages of the various fuel cell designs? - What size power systems have been produced and how well have they operated? Fuel cells are electrochemical energy conversion devices that directly convert chemical energy of a fuel to electricity, without combustion of the fuel. In this sense, they are similar to batteries. However, unlike a battery, where life is limited by the amount of chemical that is stored in it, fuel cells produce electricity as long as fuel is supplied. Thus, one might say that fuel cells are continuous batteries. Like batteries, there are many types of fuel cells: - Polymer electrolyte fuel cells are the most commonly discussed in the general interest media--newspapers, magazines and television. These fuel cells operate at {approx}90 degrees C and are the primary candidates for use in automobiles. - Alkaline fuel cells have been used in our space program since the early days of the Gemini and Apollo missions. - Phosphoric acid fuel cells are currently the most advanced on the market and are being commercialized by a division of United Technologies. - Solid oxide fuel cells (SOFCs) are based on zirconia electrolyte. This article concentrates on ceramic SOFCs.

  18. Fuel cells: A survey

    NASA Technical Reports Server (NTRS)

    Crowe, B. J.

    1973-01-01

    A survey of fuel cell technology and applications is presented. The operating principles, performance capabilities, and limitations of fuel cells are discussed. Diagrams of fuel cell construction and operating characteristics are provided. Photographs of typical installations are included.

  19. High Energy Density Regenerative Fuel Cell Systems for Terrestrial Applications

    NASA Technical Reports Server (NTRS)

    Burke, Kenneth A.

    1999-01-01

    Regenerative Fuel Cell System (RFCS) technology for energy storage has been a NASA power system concept for many years. Compared to battery-based energy storage systems, RFCS has received relatively little attention or resources for development because the energy density and electrical efficiency were not sufficiently attractive relative to advanced battery systems. Even today, RFCS remains at a very low technology readiness level (TRL of about 2 indicating feasibility has been demonstrated). Commercial development of the Proton Exchange Membrane (PEM) fuel cells for automobiles and other terrestrial applications and improvements in lightweight pressure vessel design to reduce weight and improve performance make possible a high energy density RFCS energy storage system. The results from this study of a lightweight RFCS energy storage system for a remotely piloted, solar-powered, high altitude aircraft indicate an energy density up to 790 w-h/kg with electrical efficiency of 53.4% is attainable. Such an energy storage system would allow a solar-powered aircraft to carry hundreds of kilograms of payload and remain in flight indefinitely for use in atmospheric research, earth observation, resource mapping. and telecommunications. Future developments in the areas of hydrogen and oxygen storage, pressure vessel design, higher temperature and higher- pressure fuel cell operation, unitized regenerative fuel cells, and commercial development of fuel cell technology will improve both the energy density and electrical efficiency of the RFCS.

  20. Microfluidic platforms and fundamental electrocatalysis studies for fuel cell applications

    NASA Astrophysics Data System (ADS)

    Cohen, Jamie Lee

    The fabrication and testing of a planar membraneless microchannel fuel cell, based on a silicon microchannel, is described in detail. Laminar flow of fuel and oxidant streams, one on top of the other, prevents fuel crossover while allowing ionic transport at the interface between the two solutions. By employing laminar flow, the useful functions of a membrane are retained, while bypassing its inherent limitations. The planar design maximizes the anode and cathode areas, and elimination of the membrane affords broad flexibility in the choice of fuel and oxidant. Fuels including formic acid, methanol, ethanol, sodium borohydride and hydrogen were tested along with oxidants such as oxygen, hydrogen peroxide and potassium permanganate. Steps taken to improve voltage, current density, and overall power output have been addressed, including the testing of a dual electrolyte system and the use of micro-patterned electrode surfaces to enhance fuel utilization. As the complexity of the fuels studied in the microchannel fuel cell increased, it was imperative to characterize these fuels using electrochemical techniques prior to utilization in the fuel cell. The oxidation pathway of the liquid fuel methanol was studied rigorously because of its importance for micro-fuel cell applications. Activation energies for methanol oxidation at a Ptpoly surface were determined using electrochemical techniques, providing a benchmark for the comparison of activation energies of other Pt-based electrocatalysts for methanol oxidation at a given potential. A protocol to obtain Ea values was established in three different electrolytes and experimental parameters that influence the magnitude of these values are discussed in detail. The oxidation pathways of sodium borohydride were also examined at Au, Pt, and Pd surfaces using cyclic voltammetry, chronoamperometry, and rotating disk electrode voltammetry. In addition to studies on bulk Ptpoly surfaces, new bulk intermetallic catalysts were

  1. Application of XPS to study electrocatalysts for fuel cells

    NASA Astrophysics Data System (ADS)

    Corcoran, C. J.; Tavassol, H.; Rigsby, M. A.; Bagus, P. S.; Wieckowski, A.

    Analysis of the surface is paramount to understanding the reactivity, selectivity, and catalytic ability of substances. In particular, this understanding is required to make an efficient use of the catalytic surfaces in fuel cells. X-ray photoelectron spectroscopy (XPS) allows determination of changes in the electronic structure for different surface preparation and composition based, mainly, on shifts of the binding energies of core-level electrons. It is also an ideal method that allows identification of the surface or near surface species in relation to fuel cell catalysis. However, the fundamental theoretical concepts, which are used to analyze and interpret XPS spectra are sometimes not correctly understood or correctly applied. In this review, we not only report on XPS operational parameters in use for fuel cell electrocatalysis, but, more significantly, we review and provide rigorous definitions of fundamental concepts used to understand XPS spectra, including the separation of initial and final state effects and the relaxation of valence electrons to screen core-holes. An additional direction of our review is to show the relationships between XPS binding energy shifts and XPS satellite structure with chemical bonding and chemical interactions. However, our primary concern is to provide reviews of representative cases of the application of XPS to solving fuel cell and electrocatalysis-related problems, highlighting progress in this laboratory. We begin with descriptions of essential issues in fuel cell science and with a review of key concepts of XPS. Then, we briefly report on the XPS instrumentation, after which, studies of fundamental importance to electrochemical processes are reviewed. This review includes an overview of complex organic and biological systems in relation to fuel cell electrocatalysis (probed via XPS). We conclude with a discussion of modern developments in XPS methodology.

  2. PEM fuel cell stack development for automotive applications

    SciTech Connect

    Ernst, W.D.

    1996-12-31

    Presently, the major challenges to the introduction of fuel cell power systems for automotive applications are to maximize the effective system power density and minimize cost. The material cost, especially for Platinum, had been a significant factor until recent advances by Los Alamos National Laboratory and others in low Platinum loading electrode design has brought these costs within control. Since the initiation of its PEM stack development efforts, MTI has focused on applying its system and mechanical engineering heritage on both increasing power density and reducing cost. In May of 1995, MTI was selected (along with four other companies) as a subcontractor by the Ford Motor Company to participate in Phase I of the DOE Office of Transportation Technology sponsored PNGV Program entitled: {open_quotes}Direct-Hydrogen-Fueled Proton-Exchange-Membrane (PEM) Fuel Cell System for Transportation Applications{close_quotes}. This Program was instituted to: (1) Advance the performance and economic viability of a direct-hydrogen-fueled PEM fuel cell system, (2) Identify the critical problems that must be resolved before system scale-up and vehicle integration, and (3) Integrate the fuel cell power system into a sub-scale vehicle propulsion system. The Phase I objective was to develop and demonstrate a nominal 10 kW stack meeting specific criteria. Figure I is a photograph of the stack used for these demonstrations. After completion of Phase I, MTI was one of only two companies selected to continue into Phase II of the Program. This paper summarizes Phase I stack development and results.

  3. Solid Acid Fuel Cell Stack for APU Applications

    SciTech Connect

    Duong, Hau H.

    2011-04-15

    Solid acid fuel cell technology affords the opportunity to operate at the 200-300 degree centigrade regime that would allow for more fuel flexibility, compared to polymer electrode membrane fuel cell, while avoiding the relatively more expensive and complex system components required by solid oxide fuel cell. This project addresses many factors such as MEA size scalability, fuel robustness, stability, etc., that are essential for successful commercialization of the technology.

  4. H2S removal with ZnO during fuel processing for PEM fuel cell applications

    SciTech Connect

    Li, Liyu; King, David L.

    2006-09-15

    The possibility of using ZnO as a H2S absorbent to protect catalysts in the gasoline and diesel fuel processor for PEM fuel cell applications was studied. It is possible to use commercial ZnO absorbent as a guard bed to protect the PROX catalyst and PEM fuel cell. However, it is not feasible to use ZnO to protect high and low temperature WGS catalysts, most likely due to COS formation via reactions CO + H2S = COS + H2 and CO2 + H2S = COS + H2O.

  5. Direct-hydrogen-fueled proton-exchange-membrane fuel cell system for transportation applications

    SciTech Connect

    Oei, D.; Adams, J.A.; Kinnelly, A.A.

    1997-07-01

    In partial fulfillment of the U.S. Department of Energy Contract No. DE-ACO2-94CE50389, {open_quotes}Direct Hydrogen-Fueled Proton-Exchange-Membrane (PEM) Fuel Cell System for Transportation Applications{close_quotes}, this conceptual vehicle design report addresses the design and packaging of battery augmented fuel cell powertrain vehicles. This report supplements the {open_quotes}Conceptual Vehicle Design Report - Pure Fuel Cell Powertrain Vehicle{close_quotes} and includes a cost study of the fuel cell power system. The three classes of vehicles considered in this design and packaging exercise are the same vehicle classes that were studied in the previous report: the Aspire, representing the small vehicle class; the AIV (Aluminum Intensive Vehicle) Sable, representing the mid-size vehicle; and the E-150 Econoline, representing the van-size class. A preliminary PEM fuel cell power system manufacturing cost study is also presented. As in the case of the previous report concerning the {open_quotes}Pure Fuel Cell Powertrain Vehicle{close_quotes}, the same assumptions are made for the fuel cell power system. These assumptions are fuel cell system power densities of 0.33 kW/ka and 0.33 kW/l, platinum catalyst loading of less than or equal to 0.25 mg/cm{sup 2} total, and hydrogen tanks containing compressed gaseous hydrogen under 340 atm (5000 psia) pressure. The batteries considered for power augmentation of the fuel cell vehicle are based on the Ford Hybrid Electric Vehicle (HEV) program. These are state-of-the-art high power lead acid batteries with power densities ranging from 0.8 kW/kg to 2 kW/kg. The results reported here show that battery augmentation provides the fuel cell vehicle with a power source to meet instant high power demand for acceleration and start-up. Based on the assumptions made in this report, the packaging of the battery augmented fuel cell vehicle appears to be as feasible as the packaging of the pure fuel cell powered vehicle.

  6. Fuel cell power plants in a distributed generator application

    SciTech Connect

    Smith, M.J.

    1996-12-31

    ONSI`s (a subsidiary of International Fuel Cells Corporation) world wide fleet of 200-kW PC25{trademark} phosphoric acid fuel cell power plants which began operation early in 1992 has shown excellent performance and reliability in over 1 million hours of operation. This experience has verified the clean, quiet, reliable operation of the PC25 and confirmed its application as a distributed generator. Continuing product development efforts have resulted in a one third reduction of weight and volume as well as improved installation and operating characteristics for the PC25 C model. Delivery of this unit began in 1995. International Fuel Cells (IFC) continues its efforts to improve product design and manufacturing processes. This progress has been sustained at a compounded rate of 10 percent per year since the late 1980`s. These improvements will permit further reductions in the initial cost of the power plant and place increased emphasis on market development as the pacing item in achieving business benefits from the PC25 fuel cell. Derivative product opportunities are evolving with maturation of the technologies in a commercial environment. The recent announcement of Praxair, Inc., and IFC introducing a non-cryogenic hydrogen supply system utilizing IFC`s steam reformer is an example. 11 figs.

  7. Application of alternating current impedance to fuel cell modeling

    SciTech Connect

    Springer, T.E.

    1999-05-02

    AC impedance has provided a useful diagnostic tool in the Los Alamos polymer electrolyte fuel cell (PEFC) program. The author reviews the techniques he has used in ac impedance modeling. These techniques include equation implementation, model simplification and verification, least squares fitting, application of two-dimensional Laplace equation solvers handling complex interfacial boundary conditions, and interpretation of impedance features. The separate features of the complete electrode model are explained by analytic examples.

  8. Advanced fuel cells for transportation applications. Final report

    SciTech Connect

    1998-02-10

    This Research and Development (R and D) contract was directed at developing an advanced technology compressor/expander for supplying compressed air to Proton Exchange Membrane (PEM) fuel cells in transportation applications. The objective of this project was to develop a low-cost high-efficiency long-life lubrication-free integrated compressor/expander utilizing scroll technology. The goal of this compressor/expander was to be capable of providing compressed air over the flow and pressure ranges required for the operation of 50 kW PEM fuel cells in transportation applications. The desired ranges of flow, pressure, and other performance parameters were outlined in a set of guidelines provided by DOE. The project consisted of the design, fabrication, and test of a prototype compressor/expander module. The scroll CEM development program summarized in this report has been very successful, demonstrating that scroll technology is a leading candidate for automotive fuel cell compressor/expanders. The objectives of the program are: develop an integrated scroll CEM; demonstrate efficiency and capacity goals; demonstrate manufacturability and cost goals; and evaluate operating envelope. In summary, while the scroll CEM program did not demonstrate a level of performance as high as the DOE guidelines in all cases, it did meet the overriding objectives of the program. A fully-integrated, low-cost CEM was developed that demonstrated high efficiency and reliable operation throughout the test program. 26 figs., 13 tabs.

  9. Electrocatalysts by atomic layer deposition for fuel cell applications

    DOE PAGES

    Cheng, Niancai; Shao, Yuyan; Liu, Jun; Sun, Xueliang

    2016-01-22

    Here, fuel cells are a promising technology solution for reliable and clean energy because they offer high energy conversion efficiency and low emission of pollutants. However, high cost and insufficient durability are considerable challenges for widespread adoption of polymer electrolyte membrane fuel cells (PEMFCs) in practical applications. Current PEMFCs catalysts have been identified as major contributors to both the high cost and limited durability. Atomic layer deposition (ALD) is emerging as a powerful technique for solving these problems due to its exclusive advantages over other methods. In this review, we summarize recent developments of ALD in PEMFCs with a focusmore » on design of materials for improved catalyst activity and durability. New research directions and future trends have also been discussed.« less

  10. Assessment of industrial applications for fuel cell cogeneration systems

    NASA Technical Reports Server (NTRS)

    Stickles, R. P.; Oneill, J. K.; Smith, E. H.

    1978-01-01

    The fuel cell energy systems are designed with and without a utility connection for emergency back-up power. Sale of electricity to the utility during periods of low plant demand is not considered. For each of the three industrial applications, conceptual designs were also developed for conventional utility systems relying on purchased electric power and fossil-fired boilers for steam/hot water. The capital investment for each energy system is estimated. Annual operating costs are also determined for each system. These cost estimates are converted to levelized annual costs by applying appropriate economic factors. The breakeven electricity price that would make fuel cell systems competitive with the conventional systems is plotted as a function of naphtha price. The sensitivity of the breakeven point to capital investment and coal price is also evaluated.

  11. Optimizing Escherichia coli's metabolism for fuel cell applications

    NASA Astrophysics Data System (ADS)

    Nieves, Ismael U.

    In the last few years there have been many publications about applications that center on the generation of electrons from bacterial cells. These applications take advantage of the catabolic diversity of microbes to generate electrical power. The practicality of these applications depends on the microorganism's ability to effectively donate electrons, either directly to the electrode or indirectly through the use of a mediator. After establishing the limitations of electrical output in microbial fuel cells (MFCs) imposed by the bacterial cells, a spectrophotometric assay measuring the indirect reduction of the electronophore neutral red via iron reduction was used to measure electron production from Escherichia coli resting cells. Using this assay I identified NADH dehydrogenase I as a likely site of neutral red reduction. The only previously reported site of interaction between E. coli cells and NR is at the hydrogenases. Although we cannot rule out the possibility that NR is reduced by soluble hydrogenases in the cytoplasm, this previous report indicated that hydrogenase activity does not account for all of the NR reduction activity. Supporting this, data in this thesis suggest that the hydrogenases play a small role in NR reduction. It seems that NR reduction is largely taking place within the cytoplasmic membrane of the bacterial cells, serving as a substrate of enzymes that typically reduce quinones. Furthermore, it seems that under the experimental conditions used here, E. coli's catabolism of glucose is rather inefficient. Instead of using the complete TCA cycle, the bacterial cells are carrying out fermentation, leading to incomplete oxidation of the fuel and low yields of electrons. The results obtained from the TC31 strain suggest that eliminating fermentation pathways to improve NR reduction was the correct approach. Following up on this a new strain was created, KN02, which, in addition to the mutations on strain TC31, lacks acetate kinase activity.

  12. Synthesis and Characterization of Polymers for Fuel Cells Application

    NASA Technical Reports Server (NTRS)

    Tytko, Stephen F.

    2003-01-01

    The goal of this summer research is to prepare Polymer Exchange Membranes (PEM s) for fuel cell application. Several high temperature polymers such as polybenzimidazoles and polyether ketones were known to possess good high temperature stability and had been investigated by post-sulfonation to yield sulfonated polymers. The research project will involve two approaches: 1. Synthesis of polybenzimidazoles and then react with alkyl sultonse to attach an aliphatic sulfonic groups. 2. Synthesis of monomers containing sulfonic acid units either on a aromatic ring or on an aliphatic chain and then polymerize the monomers to form high molecular weight sulfonate polymers.

  13. Direct Methanol Fuel Cell Prototype Demonstration for Consumer Electronics Applications

    SciTech Connect

    Carlstrom, Charles, M., Jr.

    2009-07-07

    This report is the final technical report for DOE Program DE-FC36-04GO14301 titled “Direct Methanol Fuel Cell Prototype Demonstration for Consumer Electronics Applications”. Due to the public nature of this report some of the content reported in confidential reports and meetings to the DOE is not covered in detail in this report and some of the content has been normalized to not show actual values. There is a comparison of the projects accomplishments with the objectives, an overview of some of the key subsystem work, and a review of the three levels of prototypes demonstrated during the program. There is also a description of the eventual commercial product and market this work is leading towards. The work completed under this program has significantly increased the understanding of how Direct Methanol Fuel Cells (DMFC) can be deployed successfully to power consumer electronic devices. The prototype testing has demonstrated the benefits a direct methanol fuel cell system has over batteries typically used for powering consumer electronic devices. Three generations of prototypes have been developed and tested for performance, robustness and life. The technologies researched and utilized in the fuel cell stack and related subsystems for these prototypes are leveraged from advances in other industries such as the hydrogen fueled PEM fuel cell industry. The work under this program advanced the state of the art of direct methanol fuel cells. The system developed by MTI micro fuel cells aided by this program differs significantly from conventional DMFC designs and offers compelling advantages in the areas of performance, life, size, and simplicity. The program has progressed as planned resulting in the completion of the scope of work and available funding in December 2008. All 18 of the final P3 prototypes builds have been tested and the results showed significant improvements over P2 prototypes in build yield, initial performance, and durability. The systems have

  14. Analytical performance of direct-hydrogen-fueled polymer electrolyte fuel cell (PEFC) systems for transportation applications.

    SciTech Connect

    Doss, E. D.

    1998-06-02

    The performance of a stand-alone polymer electrolyte fuel cell (PEFC) system directly fueled by hydrogen has been evaluated for transportation vehicles. The study was carried out using a systems analysis code and a vehicle analysis code. The systems code includes models for the various PEFC components and is applicable for steady-state and transient situations. At the design point the system efficiency is above 50% for a 50-kW system. The efficiency improves under partial load and approaches 60% at 40% load, as the fuel cell operating point moves to lower current densities on the V-I polarization curve. At much lower loads, the system efficiency drops because of the deterioration in the performance of the compressor, expander, and eventually the fuel cell. The system performance suffers at lower temperatures, as the V-I characteristic curve for the fuel cell shifts downward because of the increased ohmic losses. The results of the transient analysis indicate that the hydrogen-fueled PEFC system can start rather rapidly, within seconds from ambient conditions. However, the warm-up time constant to reach the design operating temperatures is about 180 s. It is important during this period for the coolant to bypass the system radiator until the coolant temperature approaches the design temperature for the fuel cell. The systems analysis code has been applied to two mid-size vehicles: the near-term Ford AIV Sable and the future P2000 vehicle. The results of this study show that the PEFC system in these vehicles can respond well to the demands of the FUDS and Highway driving cycles, with both warm and cold starting conditions. The results also show that the fuel-cell AIV Sable vehicle has impressive gains in fuel economy over that of the internal combustion engine vehicle. However, this vehicle will not be able to meet the PNGV goal of 80 mpg. On the other hand, the P2000 vehicle approaches this goal with variable efficiency of the compressor and expander. It is expected

  15. Analytical performance of direct-hydrogen fueled polymer electrolyte fuel cell (PEFC) systems for transportation applications

    SciTech Connect

    Doss, E.D.; Ahluwalia, R.; Kumar, R.

    1998-07-01

    The performance of a stand-alone polymer electrolyte fuel cell (PEFC) system directly fueled by hydrogen has been evaluated for transportation vehicles. The study was carried out using a systems analysis code and a vehicle analysis code. The systems code includes models for the various PEFC components and is applicable for steady-state and transient situations. At the design point, the system efficiency is above 50% for a 50-kW system. The efficiency improves under partial load and approaches 60% at 40% load, as the fuel cell operating point moves to lower current densities on the V-I polarization curve. At much lower loads, the system efficiency drops because of the deterioration in the performance of the compressor, expander, and eventually the fuel cell. The system performance suffers at lower temperatures, as the V-I characteristic curve for the fuel cell shifts downward because of the increased ohmic losses. The results of the transient analysis indicate that the hydrogen-fueled PEFC system can start rather rapidly, within seconds from ambient conditions. However, the warm-up time constant to reach the design operating temperatures is about 180 s. It is important during this period for the coolant to bypass the system radiator until the coolant temperature approaches the design temperature for the fuel cell. The systems analysis code has been applied to two mid-size vehicles: the near-term Ford AIV Sable and the future P2000 vehicle. The results of this study show that the PEFC system in these vehicles can respond well to the demands of the FUDS and Highway driving cycles, with both warm and cold starting conditions. The results also show that the fuel-cell AIV Sable vehicle has impressive gains in fuel economy over that of the internal combustion engine vehicle. However, this vehicle will not be able to meet the PNGV goal of 80 mpg. On the other hand, the P2000 vehicle approaches this goal with variable efficiency of the compressor and expander. It is

  16. Hydrodesulfurization and prereforming of logistic fuels for use in fuel cell applications

    SciTech Connect

    Piwetz, M.M.; Larsen, J.S.; Christensen, T.S.

    1996-12-31

    Fuel cell development programs have traditionally emphasized the use of natural gas as the primary fuel. However, to meet strategic requirements for fuel cells in military use, the fuel of choice must be accessible throughout the world, easily transported and stored, and compatible with other military uses. The United States military`s logistic fuels (DF-2 diesel or JP-8 jet fuel) meet these requirements. The objectives of this program were to design and construct a fuel processing system (FPS) and by connecting the FPS with a solid oxide fuel cell (SOFC) and molten carbonate fuel cell (MCFC), respectively, to demonstrate that such a system can be used to convert diesel or jet-fuel into a feed stream compatible with the fuel cell.

  17. PEM fuel cell bipolar plate material requirements for transportation applications

    SciTech Connect

    Borup, R.L.; Stroh, K.R.; Vanderborgh, N.E.

    1996-04-01

    Cost effective bipolar plates are currently under development to help make proton exchange membrane (PEM) fuel cells commercially viable. Bipolar plates separate individual cells of the fuel cell stack, and thus must supply strength, be electrically conductive, provide for thermal control of the fuel stack, be a non-porous materials separating hydrogen and oxygen feed streams, be corrosion resistant, provide gas distribution for the feed streams and meet fuel stack cost targets. Candidate materials include conductive polymers and metal plates with corrosion resistant coatings. Possible metals include aluminium, titanium, iron/stainless steel and nickel.

  18. DOE/FORD fuel cell contract for automotive application

    SciTech Connect

    Djong-Gie Oei

    1995-08-01

    The objectives of the contract are twofold. The first objective is to assess the feasibility of using a direct hydrogen fueled PEM fuel cell engine to power a midsize passenger car through the various drive cycles and test such a propulsion system on a test bed. The second objective is to study the supply infrastructure and safety aspects of hydrogen for future practical implementation of PEM fuel cells.

  19. NASA Non-Flow-Through PEM Fuel Cell System for Aerospace Applications

    NASA Technical Reports Server (NTRS)

    Araghi, Koorosh R.

    2011-01-01

    NASA is researching passive NFT Proton Exchange Membrane (PEM) fuel cell technologies for primary fuel cell power plants in air-independent applications. NFT fuel cell power systems have a higher power density than flow through systems due to both reduced parasitic loads and lower system mass and volume. Reactant storage still dominates system mass/volume considerations. NFT fuel cell stack testing has demonstrated equivalent short term performance to flow through stacks. More testing is required to evaluate long-term performance.

  20. Five Kilowatt Fuel Cell Demonstration for Remote Power Applications

    SciTech Connect

    Dennis Witmer; Tom Johnson; Jack Schmid

    2008-12-31

    While most areas of the US are serviced by inexpensive, dependable grid connected electrical power, many areas of Alaska are not. In these areas, electrical power is provided with Diesel Electric Generators (DEGs), at much higher cost than in grid connected areas. The reasons for the high cost of power are many, including the high relative cost of diesel fuel delivered to the villages, the high operational effort required to maintain DEGs, and the reverse benefits of scale for small utilities. Recent progress in fuel cell technologies have lead to the hope that the DEGs could be replaced with a more efficient, reliable, environmentally friendly source of power in the form of fuel cells. To this end, the University of Alaska Fairbanks has been engaged in testing early fuel cell systems since 1998. Early tests were conducted on PEM fuel cells, but since 2001, the focus has been on Solid Oxide Fuel Cells. In this work, a 5 kW fuel cell was delivered to UAF from Fuel Cell Technologies of Kingston, Ontario. The cell stack is of a tubular design, and was built by Siemens Westinghouse Fuel Cell division. This stack achieved a run of more than 1 year while delivering grid quality electricity from natural gas with virtually no degradation and at an electrical efficiency of nearly 40%. The project was ended after two control system failures resulted in system damage. While this demonstration was successful, considerable additional product development is required before this technology is able to provide electrical energy in remote Alaska. The major issue is cost, and the largest component of system cost currently is the fuel cell stack cost, although the cost of the balance of plant is not insignificant. While several manufactures are working on schemes for significant cost reduction, these systems do not as yet provide the same level of performance and reliability as the larger scale Siemens systems, or levels that would justify commercial deployment.

  1. PREPARATION AND CHARACTERIZATION OF SOLID ELECTROLYTES: FUEL CELL APPLICATIONS

    SciTech Connect

    Rambabu Bobba; Josef Hormes; T. Wang; Jaymes A. Baker; Donald G. Prier; Tommy Rockwood; Dinesha Hawkins; Saleem Hasan; V. Rayanki

    1997-12-31

    conducting solid electrolytes are successfully used for battery, fuel cell and sensor applications.

  2. Fuel cells seminar

    SciTech Connect

    1996-12-01

    This year`s meeting highlights the fact that fuel cells for both stationary and transportation applications have reached the dawn of commercialization. Sales of stationary fuel cells have grown steadily over the past 2 years. Phosphoric acid fuel cell buses have been demonstrated in urban areas. Proton-exchange membrane fuel cells are on the verge of revolutionizing the transportation industry. These activities and many more are discussed during this seminar, which provides a forum for people from the international fuel cell community engaged in a wide spectrum of fuel cell activities. Discussions addressing R&D of fuel cell technologies, manufacturing and marketing of fuel cells, and experiences of fuel cell users took place through oral and poster presentations. For the first time, the seminar included commercial exhibits, further evidence that commercial fuel cell technology has arrived. A total of 205 papers is included in this volume.

  3. Commercialization of proton exchange membrane fuel cells for transportation applications

    SciTech Connect

    Wismer, L.

    1996-04-01

    Environmental concerns with air quality and global warming have triggered strict federal ambient ozone air quality standards. Areas on non-attainment of these standards exist across the United States. Because it contains several of the most difficult attainment areas, the State of California has adopted low emission standards including a zero emission vehicle mandate that has given rise to development of hybrid electric vehicles, both battery-powered and fuel-cell powered. Fuel cell powered vehicles, using on-board hydrogen as a fuel, share the non-polluting advantage of the battery electric vehicle while offering at least three times the range today`s battery technology.

  4. Direct-hydrogen-fueled proton-exchange-membrane fuel cell system for transportation applications: Conceptual vehicle design report pure fuel cell powertrain vehicle

    SciTech Connect

    Oei, D.; Kinnelly, A.; Sims, R.; Sulek, M.; Wernette, D.

    1997-02-01

    In partial fulfillment of the Department of Energy (DOE) Contract No. DE-AC02-94CE50389, {open_quotes}Direct-Hydrogen-Fueled Proton-Exchange-Membrane (PEM) Fuel Cell for Transportation Applications{close_quotes}, this preliminary report addresses the conceptual design and packaging of a fuel cell-only powered vehicle. Three classes of vehicles are considered in this design and packaging exercise, the Aspire representing the small vehicle class, the Taurus or Aluminum Intensive Vehicle (AIV) Sable representing the mid-size vehicle and the E-150 Econoline representing the van-size class. A fuel cell system spreadsheet model and Ford`s Corporate Vehicle Simulation Program (CVSP) were utilized to determine the size and the weight of the fuel cell required to power a particular size vehicle. The fuel cell power system must meet the required performance criteria for each vehicle. In this vehicle design and packaging exercise, the following assumptions were made: fuel cell power system density of 0.33 kW/kg and 0.33 kg/liter, platinum catalyst loading less than or equal to 0.25 mg/cm{sup 2} total and hydrogen tanks containing gaseous hydrogen under 340 atm (5000 psia) pressure. The fuel cell power system includes gas conditioning, thermal management, humidity control, and blowers or compressors, where appropriate. This conceptual design of a fuel cell-only powered vehicle will help in the determination of the propulsion system requirements for a vehicle powered by a PEMFC engine in lieu of the internal combustion (IC) engine. Only basic performance level requirements are considered for the three classes of vehicles in this report. Each vehicle will contain one or more hydrogen storage tanks and hydrogen fuel for 560 km (350 mi) driving range. Under these circumstances, the packaging of a fuel cell-only powered vehicle is increasingly difficult as the vehicle size diminishes.

  5. Microscale Fuel Cells

    SciTech Connect

    Holladay, Jamie D.; Viswanathan, Vish V.

    2005-11-03

    Perhaprs some of the most innovative work on fuel cells has been the research dedicated to applying silicon fabrication techniques to fuel cells technology creating low power microscale fuel cells applicable to microelectro mechanical systems (MEMS), microsensors, cell phones, PDA’s, and other low power (0.001 to 5 We) applications. In this small power range, fuel cells offer the decoupling of the energy converter from the energy storage which may enable longer operating times and instant or near instant charging. To date, most of the microscale fuel cells being developed have been based on proton exchange membrane fuel cell technology (PEMFC) or direct methanol fuel cell (DMFC) technology. This section will discuss requirements and considerations that need to be addressed in the development of microscale fuel cells, as well as some proposed designs and fabrication strategies.

  6. Development Status of PEM Non-Flow-Through Fuel Cell System Technology for NASA Applications

    NASA Technical Reports Server (NTRS)

    Hoberecht, Mark A.; Jakupca, Ian J.

    2011-01-01

    Today s widespread development of proton-exchange-membrane (PEM) fuel cell technology for commercial users owes its existence to NASA, where fuel cell technology saw its first applications. Beginning with the early Gemini and Apollo programs, and continuing to this day with the Shuttle Orbiter program, fuel cells have been a primary source of electrical power for many NASA missions. This is particularly true for manned missions, where astronauts are able to make use of the by-product of the fuel cell reaction, potable water. But fuel cells also offer advantages for unmanned missions, specifically when power requirements exceed several hundred watts and primary batteries are not a viable alternative. In recent years, NASA s Exploration Technology Development Program (ETDP) funded the development of fuel cell technology for applications that provide both primary power and regenerative fuel cell energy storage for planned Exploration missions that involved a return to the moon. Under this program, the Altair Lunar Lander was a mission requiring fuel cell primary power. There were also various Lunar Surface System applications requiring regenerative fuel cell energy storage, in which a fuel cell and electrolyzer combine to form an energy storage system with hydrogen, oxygen, and water as common reactants. Examples of these systems include habitat modules and large rovers. In FY11, the ETDP has been replaced by the Enabling Technology Development and Demonstration Program (ETDDP), with many of the same technology goals and requirements applied against NASA s revised Exploration portfolio.

  7. Improved alkaline hydrogen/air fuel cells for transportation applications

    SciTech Connect

    McBreen, J; Kissel, G; Kordesch, K V; Kulesa, F; Taylor, E J; Gannon, E; Srinivasan, S

    1980-01-01

    Considerable progress has been made in the last few years on improvement of alkaline air electrodes for air depolarized chlor-alkali cells. Some of these electrodes from Union Carbide Corporation have been evaluated at Brookhaven National Laboratory in alkaline hydrogen/air fuel cells. In initial tests with 289 cm/sup 2/ electrodes, power densities of 100 mW/cm/sup 2/ were obtained at 0.65 V. This compares with power densities of 27 mW/cm/sup 2/ obtained by Kordesch in his vehicle fuel cell in the late sixties. Further improvements in the air electrode flow field yielded power densities of 126 mW/cm/sup 2/ at 0.65 V at an operating temperature of 70/sup 0/C. At 30/sup 0/C, nearly 60% of this power could be obtained at 0.65 V. The 289 cm/sup 2/ cells were units in a 16-cell 0.5 kW module. This module yielded similar power densities, and its power/weight and power/volume are sufficiently attractive for it to be considered as a building block for a fuel cell power plant in a fuel cell/battery hybrid vehicle.

  8. The Advantages of Non-Flow-Through Fuel Cell Power Systems for Aerospace Applications

    NASA Technical Reports Server (NTRS)

    Hoberecht, Mark; Burke, Kenneth; Jakupca, Ian

    2011-01-01

    NASA has been developing proton-exchange-membrane (PEM) fuel cell power systems for the past decade, as an upgraded technology to the alkaline fuel cells which presently provide power for the Shuttle Orbiter. All fuel cell power systems consist of one or more fuel cell stacks in combination with appropriate balance-of-plant hardware. Traditional PEM fuel cells are characterized as flow-through, in which recirculating reactant streams remove product water from the fuel cell stack. NASA recently embarked on the development of non-flow-through fuel cell systems, in which reactants are dead-ended into the fuel cell stack and product water is removed by internal wicks. This simplifies the fuel cell power system by eliminating the need for pumps to provide reactant circulation, and mechanical water separators to remove the product water from the recirculating reactant streams. By eliminating these mechanical components, the resulting fuel cell power system has lower mass, volume, and parasitic power requirements, along with higher reliability and longer life. These improved non-flow-through fuel cell power systems therefore offer significant advantages for many aerospace applications.

  9. Fuel Cell Handbook update

    SciTech Connect

    Owens, W.R.; Hirschenhofer, J.H.; Engleman, R.R. Jr.; Stauffer, D.B.

    1993-11-01

    The objective of this work was to update the 1988 version of DOE`s Fuel Cell Handbook. Significant developments in the various fuel cell technologies required revisions to reflect state-of-the-art configurations and performance. The theoretical presentation was refined in order to make the handbook more useful to both the casual reader and fuel cell or systems analyst. In order to further emphasize the practical application of fuel cell technologies, the system integration information was expanded. In addition, practical elements, such as suggestions and guidelines to approximate fuel cell performance, were provided.

  10. Integrated microchemical systems for fuel processing in micro fuel cell applications

    NASA Astrophysics Data System (ADS)

    Pattekar, Ashish V.

    Rapid advances in microelectronics technology over the last decade have led to the search for novel applications of miniaturization to all aspects of engineering. Microreaction engineering, which involves the development of miniature reactors on microchips for novel applications, has been a key area of interest in this quest for miniaturization. The idea of a fully integrated microplant with embedded control electronics, sensors and actuators on a single silicon chip has been gaining increasing acceptance as significant progress is being made in this area. The aim of this project has been to demonstrate a working microreaction system for hydrogen delivery to miniature proton exchange membrane (PEM) fuel cells through the catalytic steam reforming of methanol. The complete reformer - fuel cell unit is proposed as an alternative to conventional portable sources of electricity such as batteries due to its ability to provide an uninterrupted supply of electricity as long as a supply of methanol and water can be provided. This technology also offers significantly higher energy storage densities, which translates into less frequent 'recharging' through the refilling of methanol fuel. Various aspects of the design of a miniature methanol reformer on a silicon substrate are discussed with a focus on the theoretical understanding of microreactor operation and optimum utilization of the semiconductor-processing techniques used for fabricating the devices. Three prototype microreactor designs have been successfully fabricated and tested. Issues related to microchannel capping, on-chip heating and temperature sensing, introduction and trapping of catalyst particles in microchannels, microfluidic interfacing, pressure drop reduction, and thermal insulation have been addressed. Details regarding modeling and simulation of the designs to provide an insight into the working of the microreactor are presented along with a description of the microfabrication steps followed to

  11. Assembly of a Cost-Effective Anode Using Palladium Nanoparticles for Alkaline Fuel Cell Applications

    ERIC Educational Resources Information Center

    Feliciano-Ramos, Ileana; Casan~as-Montes, Barbara; García-Maldonado, María M.; Menendez, Christian L.; Mayol, Ana R.; Díaz-Vazquez, Liz M.; Cabrera, Carlos R.

    2015-01-01

    Nanotechnology allows the synthesis of nanoscale catalysts, which offer an efficient alternative for fuel cell applications. In this laboratory experiment, the student selects a cost-effective anode for fuel cells by comparing three different working electrodes. These are commercially available palladium (Pd) and glassy carbon (GC) electrodes, and…

  12. Hydrogen Research for Spaceport and Space-Based Applications: Fuel Cell Projects

    NASA Technical Reports Server (NTRS)

    Anderson, Tim; Balaban, Canan

    2008-01-01

    The activities presented are a broad based approach to advancing key hydrogen related technologies in areas such as fuel cells, hydrogen production, and distributed sensors for hydrogen-leak detection, laser instrumentation for hydrogen-leak detection, and cryogenic transport and storage. Presented are the results from research projects, education and outreach activities, system and trade studies. The work will aid in advancing the state-of-the-art for several critical technologies related to the implementation of a hydrogen infrastructure. Activities conducted are relevant to a number of propulsion and power systems for terrestrial, aeronautics and aerospace applications. Fuel cell research focused on proton exchange membranes (PEM), solid oxide fuel cells (SOFC). Specific technologies included aircraft fuel cell reformers, new and improved electrodes, electrolytes, interconnect, and seals, modeling of fuel cells including CFD coupled with impedance spectroscopy. Research was conducted on new materials and designs for fuel cells, along with using embedded sensors with power management electronics to improve the power density delivered by fuel cells. Fuel cell applications considered were in-space operations, aviation, and ground-based fuel cells such as; powering auxiliary power units (APUs) in aircraft; high power density, long duration power supplies for interplanetary missions (space science probes and planetary rovers); regenerative capabilities for high altitude aircraft; and power supplies for reusable launch vehicles.

  13. An overview of power electronics applications in fuel cell systems: DC and AC converters.

    PubMed

    Ali, M S; Kamarudin, S K; Masdar, M S; Mohamed, A

    2014-01-01

    Power electronics and fuel cell technologies play an important role in the field of renewable energy. The demand for fuel cells will increase as fuel cells become the main power source for portable applications. In this application, a high-efficiency converter is an essential requirement and a key parameter of the overall system. This is because the size, cost, efficiency, and reliability of the overall system for portable applications primarily depend on the converter. Therefore, the selection of an appropriate converter topology is an important and fundamental aspect of designing a fuel cell system for portable applications as the converter alone plays a major role in determining the overall performance of the system. This paper presents a review of power electronics applications in fuel cell systems, which include various topology combinations of DC converters and AC inverters and which are primarily used in fuel cell systems for portable or stand-alone applications. This paper also reviews the switching techniques used in power conditioning for fuel cell systems. Finally, this paper addresses the current problem encountered with DC converters and AC inverter.

  14. An Overview of Power Electronics Applications in Fuel Cell Systems: DC and AC Converters

    PubMed Central

    Ali, M. S.; Kamarudin, S. K.; Masdar, M. S.; Mohamed, A.

    2014-01-01

    Power electronics and fuel cell technologies play an important role in the field of renewable energy. The demand for fuel cells will increase as fuel cells become the main power source for portable applications. In this application, a high-efficiency converter is an essential requirement and a key parameter of the overall system. This is because the size, cost, efficiency, and reliability of the overall system for portable applications primarily depend on the converter. Therefore, the selection of an appropriate converter topology is an important and fundamental aspect of designing a fuel cell system for portable applications as the converter alone plays a major role in determining the overall performance of the system. This paper presents a review of power electronics applications in fuel cell systems, which include various topology combinations of DC converters and AC inverters and which are primarily used in fuel cell systems for portable or stand-alone applications. This paper also reviews the switching techniques used in power conditioning for fuel cell systems. Finally, this paper addresses the current problem encountered with DC converters and AC inverter. PMID:25478581

  15. An overview of power electronics applications in fuel cell systems: DC and AC converters.

    PubMed

    Ali, M S; Kamarudin, S K; Masdar, M S; Mohamed, A

    2014-01-01

    Power electronics and fuel cell technologies play an important role in the field of renewable energy. The demand for fuel cells will increase as fuel cells become the main power source for portable applications. In this application, a high-efficiency converter is an essential requirement and a key parameter of the overall system. This is because the size, cost, efficiency, and reliability of the overall system for portable applications primarily depend on the converter. Therefore, the selection of an appropriate converter topology is an important and fundamental aspect of designing a fuel cell system for portable applications as the converter alone plays a major role in determining the overall performance of the system. This paper presents a review of power electronics applications in fuel cell systems, which include various topology combinations of DC converters and AC inverters and which are primarily used in fuel cell systems for portable or stand-alone applications. This paper also reviews the switching techniques used in power conditioning for fuel cell systems. Finally, this paper addresses the current problem encountered with DC converters and AC inverter. PMID:25478581

  16. Alkaline polymer electrolyte membranes for fuel cell applications.

    PubMed

    Wang, Yan-Jie; Qiao, Jinli; Baker, Ryan; Zhang, Jiujun

    2013-07-01

    In this review, we examine the most recent progress and research trends in the area of alkaline polymer electrolyte membrane (PEM) development in terms of material selection, synthesis, characterization, and theoretical approach, as well as their fabrication into alkaline PEM-based membrane electrode assemblies (MEAs) and the corresponding performance/durability in alkaline polymer electrolyte membrane fuel cells (PEMFCs). Respective advantages and challenges are also reviewed. To overcome challenges hindering alkaline PEM technology advancement and commercialization, several research directions are then proposed.

  17. Improved Membrane Materials for PEM Fuel Cell Application

    SciTech Connect

    Kenneth A. Mauritz; Robert B. Moore

    2008-06-30

    The overall goal of this project is to collect and integrate critical structure/property information in order to develop methods that lead to significant improvements in the durability and performance of polymer electrolyte membrane fuel cell (PEMFC) materials. This project is focused on the fundamental improvement of PEMFC membrane materials with respect to chemical, mechanical and morphological durability as well as the development of new inorganically-modified membranes.

  18. SHAPE SELECTIVE NANOCATALYSTS FOR DIRECT METHANOL FUEL CELL APPLICATIONS

    SciTech Connect

    Murph, S.

    2012-09-12

    While gold and platinum have long been recognized for their beauty and value, researchers at the Savannah River National Laboratory (SRNL) are working on the nano-level to use these elements for creative solutions to our nation's energy and security needs. Multiinterdisciplinary teams consisting of chemists, materials scientists, physicists, computational scientists, and engineers are exploring unchartered territories with shape-selective nanocatalysts for the development of novel, cost effective and environmentally friendly energy solutions to meet global energy needs. This nanotechnology is vital, particularly as it relates to fuel cells.SRNL researchers have taken process, chemical, and materials discoveries and translated them for technological solution and deployment. The group has developed state-of-the art shape-selective core-shell-alloy-type gold-platinum nanostructures with outstanding catalytic capabilities that address many of the shortcomings of the Direct Methanol Fuel Cell (DMFC). The newly developed nanostructures not only busted the performance of the platinum catalyst, but also reduced the material cost and overall weight of the fuel cell.

  19. Coordinated Fuel Cell System Programs for Government and Commercial Applications: Are We in a New Era?

    NASA Technical Reports Server (NTRS)

    Warshay, Marvin; Prokopius, Paul

    1996-01-01

    Though the fuel cell was invented in 1839, it was not until the early 1960's that the fuel cell power system was developed and used for a real application, for the NASA Space Mission Gemini. Unfortunately, fuel cell power systems did not, as a result, become in widespread use. Nevertheless, a great deal of progress has been made by both government and industry, culminating in many successful fuel cell power system demonstrations. Initially, each government agency and each private organization went its own way. Later, it became evident that coordination among programs was essential. An overview is presented of the current coordinated efforts by government and industry in fuel cells, with a sufficient historical background. The primary barriers to coordination of programs were institutional and differing application requirements. Initially, in the institutional area, it was the energy crisis and the formation of DOE which fostered close working relationships among government, manufacturers, and users. The authors discuss the fuel cell power system programs (of NASA, DOE, DOT, DOC, EPRI, GRI, industry, and universities), including missions and applications, technology advances, and demonstrations. The discussion covers the new Solar Regenerative Fuel Cell (RFC) program which has space, defense, and commercial terrestrial applications, and which is an excellent example of both program coordination and the Clinton Administration's dual-use application policy.

  20. Solid oxide fuel cell application in district cooling

    NASA Astrophysics Data System (ADS)

    Al-Qattan, Ayman; ElSherbini, Abdelrahman; Al-Ajmi, Kholoud

    2014-07-01

    This paper presents analysis of the performance of a combined cooling and power (CCP) system for district cooling. The cogeneration system is designed to provide cooling for a low-rise residential district of 27,300 RT (96 MWc). A solid oxide fuel cell (SOFC) generates electric power to operate chillers, and the exhaust fuel and heat from the SOFC run gas turbines and absorption chillers. Thermal energy storage is utilized to reduce system capacity. Part-load operation strategies target maximizing energy efficiency. The operation of the system is compared through an hourly simulation to that of packaged air-conditioning units typically used to cool homes. The CCP system with the district cooling arrangement improves the cooling-to-fuel efficiency by 346%. The peak power requirement is reduced by 57% (24 MW) and the total fuel energy is reduced by 54% (750 TJ y-1). The system cuts annual carbon dioxide emissions to less than half and reduces other harmful emissions. A cost analysis of the system components and operation resulted in a 53% reduction in the cost per ton-hour of cooling over traditional systems.

  1. Fuel Cells

    ERIC Educational Resources Information Center

    Hawkins, M. D.

    1973-01-01

    Discusses the theories, construction, operation, types, and advantages of fuel cells developed by the American space programs. Indicates that the cell is an ideal small-scale power source characterized by its compactness, high efficiency, reliability, and freedom from polluting fumes. (CC)

  2. Seventh Edition Fuel Cell Handbook

    SciTech Connect

    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.

  3. Development of structured polymer electrolyte membranes for fuel cell applications

    NASA Astrophysics Data System (ADS)

    Gasa, Jeffrey

    The objective of this research was to explore structure-property relationships to develop the understanding needed for introduction of superior PEM materials. Polymer electrolyte membranes based on sulfonated poly(ether ketone ketone) (SPEKK) were fabricated using N-methyl pyrrolidone as casting solvent. The membranes were characterized in terms of properties that were relevant to fuel cell applications, such as proton conductivity, methanol permeability, and swelling properties, among others. It was found in this study that the proton conductivity of neat SPEKK membranes could reach the conductivity of commercial membranes such as NafionRTM. However, when the conductivity of SPEKK was comparable to NafionRTM, the swelling of SPEKK in water was quite excessive. The swelling problem was remedied by modifying the microstructure of SPEKK using different techniques. One of them involved blending of lightly sulfonated PEKK with highly acidic particles (sulfonated crosslinked polystyrene-SXLPS). Low sulfonation level of SPEKK was used to reduce the swelling of the membrane in water and the role of the highly acidic particles was to enhance the proton conductivity of the membrane. Because of the residual crystallinity in SPEKK with low sulfonation levels (IEC < 1 meq/g), the composite membranes exhibited excellent dimensional stability in water at elevated temperatures (30-90 °C). Also, the resistance to swelling of these composite membranes in methanol-water mixtures was far better than NafionRTM, and so was the methanol permeability. Another technique explored was blending with non-conductive polymers (poly(ether imide) and poly(ether sulfone)) to act as mechanical reinforcement. It was found that miscibility behavior of the blends had a significant impact on the transport and swelling properties of these blends, which could be explained by the blend microstructure. The miscibility behavior was found to be strongly dependent on the sulfonation level of SPEKK. The

  4. DOE FUEL CELL R&D ACTIVITIES: TRANSPORTATION, STATIONARY, AND PORTABLE POWER APPLICATIONS

    SciTech Connect

    Payne, Terry L; Garland, Nancy

    2009-01-01

    Fuel Cell R&D Activities: Transportation, Stationary, and Portable Power Applications Terry Payne, PhD, PE, Technology development Manager; and Nancy Garland, PhD, Acting Fuel Cell Team Leader, Office of Hydrogen, Fuel Cells and Infrastructure Technologies, U.S. Department of Energy* In 2007, the Department of Energy s Hydrogen Program initiated new research and development projects aimed at reducing component cost and increasing stack durability and performance of transportation and stationary fuel cells. Updated progress in the Program including highlights from the new projects includes operation of a membrane electrode assembly over 7300 with voltage cycling. Market transformation activities in the Program such as forklifts for distribution centers and fuel cells for backup power will be discussed.

  5. Fuel cell-fuel cell hybrid system

    DOEpatents

    Geisbrecht, Rodney A.; Williams, Mark C.

    2003-09-23

    A device for converting chemical energy to electricity is provided, the device comprising a high temperature fuel cell with the ability for partially oxidizing and completely reforming fuel, and a low temperature fuel cell juxtaposed to said high temperature fuel cell so as to utilize remaining reformed fuel from the high temperature fuel cell. Also provided is a method for producing electricity comprising directing fuel to a first fuel cell, completely oxidizing a first portion of the fuel and partially oxidizing a second portion of the fuel, directing the second fuel portion to a second fuel cell, allowing the first fuel cell to utilize the first portion of the fuel to produce electricity; and allowing the second fuel cell to utilize the second portion of the fuel to produce electricity.

  6. Optimal design and operation of solid oxide fuel cell systems for small-scale stationary applications

    NASA Astrophysics Data System (ADS)

    Braun, Robert Joseph

    The advent of maturing fuel cell technologies presents an opportunity to achieve significant improvements in energy conversion efficiencies at many scales; thereby, simultaneously extending our finite resources and reducing "harmful" energy-related emissions to levels well below that of near-future regulatory standards. However, before realization of the advantages of fuel cells can take place, systems-level design issues regarding their application must be addressed. Using modeling and simulation, the present work offers optimal system design and operation strategies for stationary solid oxide fuel cell systems applied to single-family detached dwellings. A one-dimensional, steady-state finite-difference model of a solid oxide fuel cell (SOFC) is generated and verified against other mathematical SOFC models in the literature. Fuel cell system balance-of-plant components and costs are also modeled and used to provide an estimate of system capital and life cycle costs. The models are used to evaluate optimal cell-stack power output, the impact of cell operating and design parameters, fuel type, thermal energy recovery, system process design, and operating strategy on overall system energetic and economic performance. Optimal cell design voltage, fuel utilization, and operating temperature parameters are found using minimization of the life cycle costs. System design evaluations reveal that hydrogen-fueled SOFC systems demonstrate lower system efficiencies than methane-fueled systems. The use of recycled cell exhaust gases in process design in the stack periphery are found to produce the highest system electric and cogeneration efficiencies while achieving the lowest capital costs. Annual simulations reveal that efficiencies of 45% electric (LHV basis), 85% cogenerative, and simple economic paybacks of 5--8 years are feasible for 1--2 kW SOFC systems in residential-scale applications. Design guidelines that offer additional suggestions related to fuel cell

  7. Proton Exchange Membrane (PEM) Fuel Cell Status and Remaining Challenges for Manned Space-Flight Applications

    NASA Technical Reports Server (NTRS)

    Reaves, Will F.; Hoberecht, Mark A.

    2003-01-01

    The Fuel Cell has been used for manned space flight since the Gemini program. Its power output and water production capability over long durations for the mass and volume are critical for manned space-flight requirements. The alkaline fuel cell used on the Shuttle, while very reliable and capable for it s application, has operational sensitivities, limited life, and an expensive recycle cost. The PEM fuel cell offers many potential improvements in those areas. NASA Glenn Research Center is currently leading a PEM fuel cell development and test program intended to move the technology closer to the point required for manned space-flight consideration. This paper will address the advantages of PEM fuel cell technology and its potential for future space flight as compared to existing alkaline fuel cells. It will also cover the technical hurdles that must be overcome. In addition, a description of the NASA PEM fuel cell development program will be presented, and the current status of this effort discussed. The effort is a combination of stack and ancillary component hardware development, culminating in breadboard and engineering model unit assembly and test. Finally, a detailed roadmap for proceeding fiom engineering model hardware to qualification and flight hardware will be proposed. Innovative test engineering and potential payload manifesting may be required to actually validate/certify a PEM fuel cell for manned space flight.

  8. Storage and production of hydrogen for fuel cell applications

    NASA Astrophysics Data System (ADS)

    Aiello, Rita

    The increased utilization of proton-exchange membrane (PEM) fuel cells as an alternative to internal combustion engines is expected to increase the demand for hydrogen, which is used as the energy source in these systems. The objective of this work is to develop and test new methods for the storage and production of hydrogen for fuel cells. Six ligand-stabilized hydrides were synthesized and tested as hydrogen storage media for use in portable fuel cells. These novel compounds are more stable than classical hydrides (e.g., NaBH4, LiAlH4) and react to release hydrogen less exothermically upon hydrolysis with water. Three of the compounds produced hydrogen in high yield (88 to 100 percent of the theoretical) and at significantly lower temperatures than those required for the hydrolysis of NaBH4 and LiAlH4. However, a large excess of water and acid were required to completely wet the hydride and keep the pH of the reaction medium neutral. The hydrolysis of the classical hydrides with steam can overcome these limitations. This reaction was studied in a flow reactor and the results indicate that classical hydrides can be hydrolyzed with steam in high yields at low temperatures (110 to 123°C) and in the absence of acid. Although excess steam was required, the pH of the condensed steam was neutral. Consequently, steam could be recycled back to the reactor. Production of hydrogen for large-scale transportation fuel cells is primarily achieved via the steam reforming, partial oxidation or autothermal reforming of natural gas or the steam reforming of methanol. However, in all of these processes CO is a by-product that must be subsequently removed because the Pt-based electrocatalyst used in the fuel cells is poisoned by its presence. The direct cracking of methane over a Ni/SiO2 catalyst can produce CO-free hydrogen. In addition to hydrogen, filamentous carbon is also produced. This material accumulates on the catalyst and eventually deactivates it. The Ni/SiO2 catalyst

  9. Removal of sulfur contaminants in methanol for fuel cell applications

    SciTech Connect

    Lee, S.H.D.; Kumar, R.; Sederquist, R.

    1996-12-31

    Equilibrium adsorption isotherm and breakthrough data were used to assess feasibility of developing a granular activated carbon (GAC) adsorber for use as a sulfur removal subsystem in transportation fuel cell systems. Results suggest that an on-board GAC adsorber may not be attractive due to size and weight constraints. However, it may be feasible to install this GAC adsorber at methanol distribution stations, where space and weight are not a critical concern. Preliminary economic analysis indicated that the GAC adsorber concept will be attractive if the spent AC can be regenerated for reuse. These preliminary analyses were made on basis of very limited breakthrough data obtained from the bench-scale testing. Optimization on dynamic testing parameters and study on regeneration of spent AC are needed.

  10. [Application of microbial fuel cell (MFC) in solid waste composting].

    PubMed

    Cui, Jinxin; Wang, Xin; Tang, Jingchun

    2012-03-01

    Microbial fuel cell (MFC) is a new technology that can recover energy from biomass with simultaneous waste treatment. This technique has been developed fast in recent years in combining with environmental techniques such as wastewater treatment, degradation of toxic pollutants and desalination. With the increase of solid waste, applying MFC in composting is promising due to its property of waste disposal with simultaneous energy generation. In this paper, the microbial community of MFCs during composting was summarized. Four major influencing factors including electrodes, separators, oxygen supplement and configurations on the performance of composting MFCs were discussed. The characteristics of composting MFC as a new technique for reducing solid waste were as follows: high microbial biomass resulted in the high current density; adaptable to different environmental conditions; self-adjustable temperature with high energy efficiency; the transportation of proton from anode to cathode were limited by different solid substrates.

  11. Anomalous oxidation states in oxide multilayers for fuel cell applications

    SciTech Connect

    Perkins, James; Fearn, Sarah; Cook, S. N.; Srinivasan, R.; Rouleau, Christopher M; Christen, Hans M; West, G. D.; Morris, R. J. H.; Fraser, H. L.; Skinner, Stephen; Kilner, John; McComb, David

    2010-01-01

    Significant interest has been directed towards interface enhanced ionic conductivity. Advanced analytical techniques including electron microscopy (TEM/STEM), electron energy loss spectroscopy (EELS), and secondary ion mass spectrometry (SIMS) have been used to characterize CeO2/Ce0.85Sm0.15O2 multilayer thin films grown by pulsed laser deposition. High quality growth is observed, but ionic conductivity measured by impedance spectroscopy and 18O tracer experiments is consistent with bulk materials. EELS analysis reveals the unusual situation of layers containing only Ce(IV) adjacent to layers containing both Ce(III) and Ce(IV). Post oxygen annealing induced oxygen diffusion and mixed oxidation states in both layers, but only in the vicinity of low angle grain boundaries perpendicular to the layers. The implications of this remarkable metastability of Ce oxidation states on the design of novel electrolytes for solid oxide fuel cells is discussed.

  12. Advanced system analysis for indirect methanol fuel cell power plants for transportation applications

    NASA Astrophysics Data System (ADS)

    Vanderborgh, Nicholas E.; McFarland, Robert D.; Huff, James R.

    The indirect methanol cell fuel concept actively pursued by the USDOE and General Motors Corporation proposes the development of an electrochemical engine (e.c.e.), an electrical generator capable for usually efficient and clean power production from methanol fuel for the transportation sector. This on-board generator works in consort with batteries to provide electrical power to drive propulsion motors for a range of electric vehicles. Success in this technology could do much to improve impacted environmental areas and to convert part of the transportation fleet to natural gas and coal derived methanol as the fuel source. These developments parallel work in Europe and Japan where various fuel cell powered vehicles, often fueled with tanked or hydride hydrogen, are under active development. Transportation applications present design challenges that are distinctly different from utility requirements, the thrust of most of previous fuel cell programs. In both cases, high conversion efficiency (fuel to electricity) is essential. However, transportation requirements dictate as well designs for high power densities, rapid transients including short times for system start up, and consumer safety. The e.c.e. system is formed from four interacting components: (1) the fuel processor; (2) the fuel cell stack; (3) the air compression and decompression device; and (4) the condensing cross flow heat exchange device.

  13. Fuel cell report to congress

    SciTech Connect

    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).

  14. Direct methanol fuel cells for transportation applications. Quarterly technical report, June 1996--September 1996

    SciTech Connect

    Fuller, T.F.; Kunz, H.R.; Moore, R.

    1996-11-01

    The purpose of this research and development effort is to advance the performance and viability of direct methanol fuel cell technology for light-duty transportation applications. For fuel cells to be an attractive alternative to conventional automotive power plants, the fuel cell stack combined with the fuel processor and ancillary systems must be competitive in terms of both performance and costs. A major advantage for the direct methanol fuel cell is that a fuel processor is not required. A direct methanol fuel cell has the potential of satisfying the demanding requirements for transportation applications, such as rapid start-up and rapid refueling. The preliminary goals of this effort are: (1) 310 W/l, (2) 445 W/kg, and (3) potential manufacturing costs of $48/kW. In the twelve month period for phase 1, the following critical areas will be investigated: (1) an improved proton-exchange membrane that is more impermeable to methanol, (2) improved cathode catalysts, and (3) advanced anode catalysts. In addition, these components will be combined to form membrane-electrode assemblies (MEA`s) and evaluated in subscale tests. Finally a conceptual design and program plan will be developed for the construction of a 5 kW direct methanol stack in phase II of the program.

  15. Chitosan and alginate types of bio-membrane in fuel cell application: An overview

    NASA Astrophysics Data System (ADS)

    Shaari, N.; Kamarudin, S. K.

    2015-09-01

    The major problems of polymer electrolyte membrane fuel cell technology that need to be highlighted are fuel crossovers (e.g., methanol or hydrogen leaking across fuel cell membranes), CO poisoning, low durability, and high cost. Chitosan and alginate-based biopolymer membranes have recently been used to solve these problems with promising results. Current research in biopolymer membrane materials and systems has focused on the following: 1) the development of novel and efficient biopolymer materials; and 2) increasing the processing capacity of membrane operations. Consequently, chitosan and alginate-based biopolymers seek to enhance fuel cell performance by improving proton conductivity, membrane durability, and reducing fuel crossover and electro-osmotic drag. There are four groups of chitosan-based membranes (categorized according to their reaction and preparation): self-cross-linked and salt-complexed chitosans, chitosan-based polymer blends, chitosan/inorganic filler composites, and chitosan/polymer composites. There are only three alginate-based membranes that have been synthesized for fuel cell application. This work aims to review the state-of-the-art in the growth of chitosan and alginate-based biopolymer membranes for fuel cell applications.

  16. Fuel cell programs in the United States for stationary power applications

    SciTech Connect

    Singer, M.

    1996-04-01

    The Department of Energy (DOE), Office of Fossil Energy, is participating with the private sector in sponsoring the development of molten carbonate fuel cell (MCFC) and solid oxide fuel cell (SOFC) technologies for application in the utility, commercial and industrial sectors. Phosphoric acid fuel cell (PAFC) development was sponsored by the Office of Fossil Energy in previous years and is now being commercialized by the private sector. Private sector participants with the Department of Energy include the Electric Power Research Institute (EPRI), the Gas Research institute (GRI), electric and gas utilities, universities, manufacturing companies and their suppliers. through continued government and private sector support, fuel cell systems are emerging power generation technologies which are expected to have significant worldwide impacts. An industry with annual sales of over a billion dollars is envisioned early in the 21st century. PAFC power plants have begun to enter the marketplace and MCFC and SOFC power plants are expected to be ready to enter the marketplace in the late 1990s. In support of the efficient and effective use of our natural resources, the fuel cell program seeks to increase energy efficiency and economic effectiveness of power generation. This is to be accomplished through effectiveness of power generation. This is accomplished through the development and commercialization of cost-effective, efficient and environmentally desirable fuel cell systems which will operate on fossil fuels in multiple and end use sectors.

  17. Solid Oxide Fuel Cell Technology Stationary Power Application Project

    SciTech Connect

    Joseph Pierre

    2009-03-05

    The objectives of this program were to: (1) Develop a reliable, cost-effective, and production-friendly technique to apply the power-enhancing layer at the interface of the air electrode and electrolyte of the Siemens SOFC; (2) Design, build, install, and operate in the field two 5 kWe SOFC systems fabricated with the state-of-the-art cylindrical, tubular cell and bundle technology and incorporating advanced module design features. Siemens successfully demonstrated, first in a number of single cell tests and subsequently in a 48-cell bundle test, a significant power enhancement by employing a power-enhancing composite interlayer at the interface between the air electrode and electrolyte. While successful from a cell power enhancement perspective, the interlayer application process was not suitable for mass manufacturing. The application process was of inconsistent quality, labor intensive, and did not have an acceptable yield. This program evaluated the technical feasibility of four interlayer application techniques. The candidate techniques were selected based on their potential to achieve the technical requirements of the interlayer, to minimize costs (both labor and material), and suitably for large-scale manufacturing. Preliminary screening, utilizing lessons learned in manufacturing tubular cells, narrowed the candidate processes to two, ink-roller coating (IRC) and dip coating (DC). Prototype fixtures were successfully built and utilized to further evaluate the two candidate processes for applying the interlayer to the high power density Delta8 cell geometry. The electrical performance of interlayer cells manufactured via the candidate processes was validated. Dip coating was eventually selected as the application technique of choice for applying the interlayer to the high power Delta8 cell. The technical readiness of the DC process and product quality was successfully and repeatedly demonstrated, and its throughput and cost are amenable to large scale

  18. Robust Joining Technology for Solid Oxide Fuel Cells Applications

    NASA Technical Reports Server (NTRS)

    Shpargel, Tarah P.; Needham, Robert J.; Singh, M.; Kung, S. C.

    2004-01-01

    Recently there has been a great deal of interest in research development and commercialization of solid oxide fuel cells (SOFCs). Joining and sealing are critical issues that will need to be addressed before SOFCs can truly perform as expected. Ceramics and metals can be difficult to join together, especially when the joint must withstand up to 900 C operating temperature of the SOFCs. The goal of the present study is to find the most suitable braze material for joining of yttria stabilized zirconia (YSZ) to stainless steel. A number of commercially available braze materials TiCuSil, TiCuNi, Copper-ABA, Gold-ABA and Gold-ABA-V have been evaluated. The oxidation behavior of the braze materials and steel substrates in air was also examined through thermogravimetric analysis. The microstructure and composition of the brazed regions have been examined by optical and scanning electron microscopy and eDS analysis. Effect of braze composition and processing conditions on the interfacial microstructure and composition of the joint regions will be presented.

  19. Energy and exergy analysis of an ethanol reforming process for solid oxide fuel cell applications.

    PubMed

    Tippawan, Phanicha; Arpornwichanop, Amornchai

    2014-04-01

    The fuel processor in which hydrogen is produced from fuels is an important unit in a fuel cell system. The aim of this study is to apply a thermodynamic concept to identify a suitable reforming process for an ethanol-fueled solid oxide fuel cell (SOFC). Three different reforming technologies, i.e., steam reforming, partial oxidation and autothermal reforming, are considered. The first and second laws of thermodynamics are employed to determine an energy demand and to describe how efficiently the energy is supplied to the reforming process. Effect of key operating parameters on the distribution of reforming products, such as H2, CO, CO2 and CH4, and the possibility of carbon formation in different ethanol reformings are examined as a function of steam-to-ethanol ratio, oxygen-to-ethanol ratio and temperatures at atmospheric pressure. Energy and exergy analysis are performed to identify the best ethanol reforming process for SOFC applications.

  20. Energy and exergy analysis of an ethanol reforming process for solid oxide fuel cell applications.

    PubMed

    Tippawan, Phanicha; Arpornwichanop, Amornchai

    2014-04-01

    The fuel processor in which hydrogen is produced from fuels is an important unit in a fuel cell system. The aim of this study is to apply a thermodynamic concept to identify a suitable reforming process for an ethanol-fueled solid oxide fuel cell (SOFC). Three different reforming technologies, i.e., steam reforming, partial oxidation and autothermal reforming, are considered. The first and second laws of thermodynamics are employed to determine an energy demand and to describe how efficiently the energy is supplied to the reforming process. Effect of key operating parameters on the distribution of reforming products, such as H2, CO, CO2 and CH4, and the possibility of carbon formation in different ethanol reformings are examined as a function of steam-to-ethanol ratio, oxygen-to-ethanol ratio and temperatures at atmospheric pressure. Energy and exergy analysis are performed to identify the best ethanol reforming process for SOFC applications. PMID:24561628

  1. Fuel cell

    SciTech Connect

    Struthers, R.C.

    1983-06-28

    An improved fuel cell comprising an anode section including an anode terminal, an anode fuel, and an anolyte electrolyte, a cathode section including a cathode terminal, an electron distributor and a catholyte electrolyte, an ion exchange section between the anode and cathode sections and including an ionolyte electrolyte, ion transfer membranes separating the ionolyte from the anolyte and the catholyte and an electric circuit connected with and between the terminals conducting free electrons from the anode section and delivering free electrons to the cathode section, said ionolyte receives ions of one polarity moving from the anolyte through the membrane related thereto preventing chemical equilibrium in the anode section and sustaining chemical reaction and the generating of free electrons therein, said ions received by the ionolyte from the anolyte release different ions from the ionolyte which move through the membrane between the ionolyte and catholyte and which add to the catholyte.

  2. Investigation of the characteristics of a stacked direct borohydride fuel cell for portable applications

    NASA Astrophysics Data System (ADS)

    Kim, Cheolhwan; Kim, Kyu-Jung; Ha, Man Yeong

    To investigate the possibility of the portable application of a direct borohydride fuel cell (DBFC), weight reduction of the stack and high stacking of the cells are investigated for practical running conditions. For weight reduction, carbon graphite is adopted as the bipolar plate material even though it has disadvantages in tight stacking, which results in stacking loss from insufficient material strength. For high stacking, it is essential to have a uniform fuel distribution among cells and channels to maintain equal electric load on each cell. In particular, the design of the anode channel is important because active hydrogen generation causes non-uniformity in the fuel flow-field of the cells and channels. To reduce the disadvantages of stacking force margin and fuel maldistribution, an O-ring type-sealing system with an internal manifold and a parallel anode channel design is adopted, and the characteristics of a single and a five-cell fuel cell stack are analyzed. By adopting carbon graphite, the stack weight can be reduced by 4.2 times with 12% of performance degradation from the insufficient stacking force. When cells are stacked, the performance exceeds the single-cell performance because of the stack temperature increase from the reduction of the radiation area from the narrow stacking of cells.

  3. Cold start simulations of a gasoline based fuel processor for mobile fuel cell applications

    NASA Astrophysics Data System (ADS)

    Springmann, S.; Bohnet, M.; Docter, A.; Lamm, A.; Eigenberger, G.

    The cold start behaviour of the gas processing unit is one crucial issue for the use of gasoline based fuel reformers for mobile fuel cell systems. In this contribution different cold start strategies for a mobile fuel reformer based on gasoline are presented and discussed. The simulation studies are based on 1-d, dynamic multiphase models for both an autothermal gasoline reformer (ATR) and a thermally integrated reforming unit consisting of an ATR, a heat exchanger and a high-temperature-shift-reactor (HTS). Setup and geometric parameters for both models correspond to pilot stage systems considered by DaimlerChrysler. Results on the reactive heat-up of the ATR by partial and total oxidation of gasoline show the impact of the air/fuel-ratio and the thermal load on the cold start duration. The use of the reformat during the rapid start-up of the ATR is mainly limited by the availability of steam for autothermal operation. Due to the high thermal capacities of the system, the whole reforming unit requires much longer time for the cold start. Especially the slow convective heat-up of the HTS restricts the conversion of CO and the subsequent use of the reformat in the fuel cell. Several options for the acceleration of the cold start were investigated. Both a simple λ-control strategy and the reactive heat-up of the HTS by (partial) oxidation of the reformat with injected air reduce the cold start time significantly. With these measures a hydrogen-rich reformat with acceptable CO-concentration is available within two minutes. Moreover, the cold start time can be further reduced, if the HTS is heated up electrically to their ignition temperature at the beginning of the cold start. Thereby the CO-conversion in the HTS already starts in the first minute and, depending on the availability of steam for the feed stream, a cold start of the reforming unit below one minute seems to be possible.

  4. Performance prediction of scalable fuel cell systems for micro-vehicle applications

    NASA Astrophysics Data System (ADS)

    St. Clair, Jeffrey Glen

    Miniature (< 500g) bio-inspired robotic vehicles are being developed for a variety of applications ranging from inspection of hazardous and remote areas to environmental monitoring. Their utility could be greatly improved by replacing batteries with fuel cells consuming high energy density fuels. This thesis surveys miniature fuel cell technologies and identifies direct methanol and sodium borohydride technologies as especially promising at small scales. A methodology for estimating overall system-level performance that accounts for the balance of plant (i.e. the extra components like pumps, blowers, etc. necessary to run the fuel cell system) is developed and used to quantify the performance of two direct methanol and one NaBH4 fuel cell systems. Direct methanol systems with water recirculation offer superior specific power (400 mW/g) and specific energy at powers of 20W and system masses of 150g. The NaBH4 fuel cell system is superior at low power (<5W) because of its more energetic fuel.

  5. Application of symmetric solid oxide fuel cell in fuel containing sulfur: I. Effect of electrodes

    NASA Astrophysics Data System (ADS)

    Tan, Wenyi; Pan, Cai; Yang, Song; Zhong, Qin

    2015-03-01

    Symmetric solid oxide fuel cells (SFCs) with double perovskite materials serving as symmetric electrodes are applied for the first time in fuel containing sulfur, aiming to explore solution to sulfur poison. Temperature-programmed techniques, including H2-TPR, O2-TPD, were used to evaluate catalytic activities of electrodes in different atmosphere, while stabilities of electrode materials in sulfur containing fuel gas were characterized in terms of phase structures, conductivity, and microstructures by SEM, four-probe method and XRD as a function of temperature and operating time. It is evidenced that Sr2CoMoO6 (denoted as SCMO) possesses better hydrogen reducibility, oxygen desorption and stability in sulfur containing fuel gas. In configuration of Sr2XMoO6 (X = Co, Ni)|Ce0.85Sm0.15O2-δ (SDC)|Sr2XMoO6, the maximum power density Pmax reaches 95 mW cm-2 for SCMO and 68 mW cm-2 for SNMO with H2-0.1% H2S at 750 °C. Lower polarization resistance of SCMO (about 2.7 Ω cm2 at 750 °C) is achieved. It is interestingly noted that SFC performance composed of ex-situ regenerated symmetric electrodes SCMO falls only by 21%, as compared to that of fresh electrodes. The combinations of thermal analysis (TG-DTA) and surface analysis (XPS) convince that an ex-situ regeneration of symmetric electrode can be realized.

  6. Stationary market applications potential of solid oxide and solid polymer fuel cell systems

    SciTech Connect

    Baker, J.N.; Fletcher, W.H.

    1996-12-31

    The UK DTI`s Advanced Fuel Cells Programme currently focuses on two main fuel cell technologies, namely the solid oxide and solid polymer systems (SOFC and SPFC), respectively. The provision of accurate and timely market data is regarded as an important part of the overall programme objectives, such as to assist both Government and industry in their appraisals of the technologies. The present study was therefore commissioned against this background, with a complementary study addressing transportation and mobile applications. The results reported herein relate to the stationary market applications potential of both SOFC and SPFC systems.

  7. Enhanced control performance and application to fuel cell systems

    NASA Astrophysics Data System (ADS)

    Shishodia, Vikram

    The inverted-pendulum virtual control lab, a simulation environment for teaching advanced concepts of process control, is designed using the LabVIEW software tool. Significant advantages of using this simulation tool for pedagogical purposes include avoiding the potential issue of schedule conflicts for securing equipment-access time in a physical laboratory and providing a learning resource that becomes accessible to students located in remote geographical places. A set of tuning relationships are proposed for standard proportional-integral controllers and proportional double-integral controllers for the purpose of tracking the slope of a ramp trajectory. Three different performance metrics are investigated to serve as the criteria for optimality, and a numerical optimization procedure is used to minimize each metric over 20,000 different plants. The proportional integral controller with tuning parameters selected to optimize value of the integral of the time-weighted absolute error is recommended for tracking the slope of a ramp trajectory. A generalized predictive control (GPC) strategy is proposed for a fuel cell system, where the controller incorporates a measured disturbance in the control design. The control objective is to maintain oxygen excess ratio at a prescribed constant value. The performance of the GPC control design is compared with that of the controllers proposed in literature for various scenarios including model uncertainty. The GPC controller has zero offset when the performance variable is measured and performs better than competing designs offered in the literature. The GPC controller is also robust with respect to model uncertainty. A battery of observers with a switching strategy is proposed for estimating the value of the performance variable when it is not measured. The GPC controller with a battery of observers has no offset demonstrating better performance than analogous designs proposed in literature. However, the control performance

  8. Handbook of fuel cell performance

    SciTech Connect

    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.

  9. Fuel cell power systems for remote applications. Phase 1 final report and business plan

    SciTech Connect

    1998-02-01

    The goal of the Fuel Cell Power Systems for Remote Applications project is to commercialize a 0.1--5 kW integrated fuel cell power system (FCPS). The project targets high value niche markets, including natural gas and oil pipelines, off-grid homes, yachts, telecommunication stations and recreational vehicles. Phase 1 includes the market research, technical and financial analysis of the fuel cell power system, technical and financial requirements to establish manufacturing capability, the business plan, and teaming arrangements. Phase 1 also includes project planning, scope of work, and budgets for Phases 2--4. The project is a cooperative effort of Teledyne Brown Engineering--Energy Systems, Schatz Energy Research Center, Hydrogen Burner Technology, and the City of Palm Desert. Phases 2 through 4 are designed to utilize the results of Phase 1, to further the commercial potential of the fuel cell power system. Phase 2 focuses on research and development of the reformer and fuel cell and is divided into three related, but potentially separate tasks. Budgets and timelines for Phase 2 can be found in section 4 of this report. Phase 2 includes: Task A--Develop a reformate tolerant fuel cell stack and 5 kW reformer; Task B--Assemble and deliver a fuel cell that operates on pure hydrogen to the University of Alaska or another site in Alaska; Task C--Provide support and training to the University of Alaska in the setting up and operating a fuel cell test lab. The Phase 1 research examined the market for power systems for off-grid homes, yachts, telecommunication stations and recreational vehicles. Also included in this report are summaries of the previously conducted market reports that examined power needs for remote locations along natural gas and oil pipelines. A list of highlights from the research can be found in the executive summary of the business plan.

  10. NASA's PEM Fuel Cell Power Plant Development Program for Space Applications

    NASA Technical Reports Server (NTRS)

    Hoberecht, Mark A.

    2008-01-01

    A three-center NASA team led by the Glenn Research Center in Cleveland, Ohio is completing a five-year PEM fuel cell power plant development program for future space applications. The focus of the program has been to adapt commercial PEM fuel cell technology for space applications by addressing the key mission requirements of using pure oxygen as an oxidant and operating in a multi-gravity environment. Competing vendors developed breadboard units in the 1 to 5 kW power range during the first phase of the program, and a single vendor developed a nominal 10-kW engineering model power pant during the second phase of the program. Successful performance and environmental tests conducted by NASA established confidence that PEM fuel cell technology will be ready to meet the electrical power needs of future space missions.

  11. Application of symmetric solid oxide fuel cell in fuel containing sulfur: I. Effect of electrodes

    NASA Astrophysics Data System (ADS)

    Tan, Wenyi; Pan, Cai; Yang, Song; Zhong, Qin

    2015-03-01

    Symmetric solid oxide fuel cells (SFCs) with double perovskite materials serving as symmetric electrodes are applied for the first time in fuel containing sulfur, aiming to explore solution to sulfur poison. Temperature-programmed techniques, including H2-TPR, O2-TPD, were used to evaluate catalytic activities of electrodes in different atmosphere, while stabilities of electrode materials in sulfur containing fuel gas were characterized in terms of phase structures, conductivity, and microstructures by SEM, four-probe method and XRD as a function of temperature and operating time. It is evidenced that Sr2CoMoO6 (denoted as SCMO) possesses better hydrogen reducibility, oxygen desorption and stability in sulfur containing fuel gas. In configuration of Sr2XMoO6 (X = Co, Ni)|Ce0.85Sm0.15O2-δ (SDC)|Sr2XMoO6, the maximum power density Pmax reaches 95 mW cm-2 for SCMO and 68 mW cm-2 for SNMO with H2-0.1% H2S at 750 °C. Lower polarization resistance of SCMO (about 2.7 Ω cm2 at 750 °C) is achieved. It is interestingly noted that SFC performance composed of ex-situ regenerated symmetric electrodes SCMO falls only by 21%, as compared to that of fresh electrodes. The combinations of thermal analysis (TG-DTA) and surface analysis (XPS) convince that an ex-situ regeneration of symmetric electrode can be realized.

  12. Hybrid Power Management Program Evaluated Fuel Cell/Ultracapacitor Combinations and Developed Other New Applications

    NASA Technical Reports Server (NTRS)

    Eichenberg, Dennis J.

    2004-01-01

    In fiscal year 2003, the continuation of the Hybrid Power Management (HPM) Program through NASA Glenn Research Center's Commercial Technology Office resulted in several new successful applications of this pioneering technology. HPM is the innovative integration of diverse, state-of-the-art power devices in an optimal configuration for space and terrestrial applications. The appropriate application and control of the various power devices significantly improves overall system performance and efficiency. The advanced power devices include ultracapacitors, fuel cells, and photovoltaics. HPM has extremely wide potential, with applications from nanowatts to megawatts--including power generation, transportation systems, biotechnology systems, and space power systems. HPM has the potential to significantly alleviate global energy concerns, improve the environment, and stimulate the economy. Fuel cells provide excellent efficiency and energy density, but do not have good power density. In contrast, ultracapacitors have excellent power density and virtually unlimited cycle life. To improve the power density of the fuel cell, the combination of fuel cells and ultracapacitors was evaluated.

  13. Performance comparison of autothermal reforming for liquid hydrocarbons, gasoline and diesel for fuel cell applications

    NASA Astrophysics Data System (ADS)

    Kang, Inyong; Bae, Joongmyeon; Bae, Gyujong

    This paper discusses the reforming of liquid hydrocarbons to produce hydrogen for fuel cell applications, focusing on gasoline and diesel due to their high hydrogen density and well-established infrastructures. Gasoline and diesel are composed of numerous hydrocarbon species including paraffins, olefins, cycloparaffins, and aromatics. We have investigated the reforming characteristics of several representative liquid hydrocarbons. In the case of paraffin reforming, H 2 yield and reforming efficiency were close to thermodynamic equilibrium status (TES), although heavier hydrocarbons required slightly higher temperatures than lighter hydrocarbons. However, the conversion efficiency was much lower for aromatics than paraffins with similar carbon number. We have also investigated the reforming performance of simulated commercial diesel and gasoline using simple synthetic diesel and gasoline compositions. Reforming performances of our formulations were in good agreement with those of commercial fuels. In addition, the reforming of gas to liquid (GTL) resulted in high H 2 yield and reforming efficiency showing promise for possible fuel cell applications.

  14. Microfluidic fuel cells

    NASA Astrophysics Data System (ADS)

    Kjeang, Erik

    Microfluidic fuel cell architectures are presented in this thesis. This work represents the mechanical and microfluidic portion of a microfluidic biofuel cell project. While the microfluidic fuel cells developed here are targeted to eventual integration with biocatalysts, the contributions of this thesis have more general applicability. The cell architectures are developed and evaluated based on conventional non-biological electrocatalysts. The fuel cells employ co-laminar flow of fuel and oxidant streams that do not require a membrane for physical separation, and comprise carbon or gold electrodes compatible with most enzyme immobilization schemes developed to date. The demonstrated microfluidic fuel cell architectures include the following: a single cell with planar gold electrodes and a grooved channel architecture that accommodates gaseous product evolution while preventing crossover effects; a single cell with planar carbon electrodes based on graphite rods; a three-dimensional hexagonal array cell based on multiple graphite rod electrodes with unique scale-up opportunities; a single cell with porous carbon electrodes that provides enhanced power output mainly attributed to the increased active area; a single cell with flow-through porous carbon electrodes that provides improved performance and overall energy conversion efficiency; and a single cell with flow-through porous gold electrodes with similar capabilities and reduced ohmic resistance. As compared to previous results, the microfluidic fuel cells developed in this work show improved fuel cell performance (both in terms of power density and efficiency). In addition, this dissertation includes the development of an integrated electrochemical velocimetry approach for microfluidic devices, and a computational modeling study of strategic enzyme patterning for microfluidic biofuel cells with consecutive reactions.

  15. Synthesis and characterization of magnesium doped cerium oxide for the fuel cell application

    NASA Astrophysics Data System (ADS)

    Kumar, Amit; Kumari, Monika; Kumar, Mintu; Kumar, Sacheen; Kumar, Dinesh

    2016-05-01

    Cerium oxide has attained much attentions in global nanotechnology market due to valuable application for catalytic, fuel additive, and widely as electrolyte in solid oxide fuel cell. Doped cerium oxide has large oxygen vacancies that allow for greater reactivity and faster ion transport. These properties make cerium oxide suitable material for SOFCs application. Cerium oxide electrolyte requires lower operation temperature which shows improvement in processing and the fabrication technique. In our work, we synthesized magnesium doped cerium oxide by the co-precipitation method. With the magnesium doping catalytic reactivity of CeO2 was increased. Synthesized nanoparticle were characterized by the XRD and UV absorption techniques.

  16. 1986 fuel cell seminar: Program and abstracts

    SciTech Connect

    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)

  17. ISRU Reactant, Fuel Cell Based Power Plant for Robotic and Human Mobile Exploration Applications

    NASA Astrophysics Data System (ADS)

    Baird, Russell S.; Sanders, Gerald; Simon, Thomas; McCurdy, Kerri

    2003-01-01

    Three basic power generation system concepts are generally considered for lander, rover, and Extra-Vehicular Activity (EVA) assistant applications for robotic and human Moon and Mars exploration missions. The most common power system considered is the solar array and battery system. While relatively simple and successful, solar array/battery systems have some serious limitations for mobile applications. For typical rover applications, these limitations include relatively low total energy storage capabilities, daylight only operating times (6 to 8 hours on Mars), relatively short operating lives depending on the operating environment, and rover/lander size and surface use constraints. Radioisotope power systems are being reconsidered for long-range science missions. Unfortunately, the high cost, political controversy, and launch difficulties that are associated with nuclear-based power systems suggests that the use of radioisotope powered landers, rovers, and EVA assistants will be limited. The third power system concept now being considered are fuel cell based systems. Fuel cell power systems overcome many of the performance and surface exploration limitations of solar array/battery power systems and the prohibitive cost and other difficulties associated with nuclear power systems for mobile applications. In an effort to better understand the capabilities and limitations of fuel cell power systems for Moon and Mars exploration applications. NASA is investigating the use of In-Situ Resource Utilization (ISRU) produced reactant, fuel cell based power plants to power robotic outpost rovers, science equipment, and future human spacecraft, surface-excursion rovers, and EVA assistant rovers. This paper will briefly compare the capabilities and limitations of fuel cell power systems relative to solar array/battery and nuclear systems, discuss the unique and enhanced missions that fuel cell power systems enable, and discuss the common technology and system attributes

  18. ISRU Reactant, Fuel Cell Based Power Plant for Robotic and Human Mobile Exploration Applications

    NASA Technical Reports Server (NTRS)

    Baird, Russell S.; Sanders, Gerald; Simon, Thomas; McCurdy, Kerri

    2003-01-01

    Three basic power generation system concepts are generally considered for lander, rover, and Extra-Vehicular Activity (EVA) assistant applications for robotic and human Moon and Mars exploration missions. The most common power system considered is the solar array and battery system. While relatively simple and successful, solar array/battery systems have some serious limitations for mobile applications. For typical rover applications, these limitations include relatively low total energy storage capabilities, daylight only operating times (6 to 8 hours on Mars), relatively short operating lives depending on the operating environment, and rover/lander size and surface use constraints. Radioisotope power systems are being reconsidered for long-range science missions. Unfortunately, the high cost, political controversy, and launch difficulties that are associated with nuclear-based power systems suggests that the use of radioisotope powered landers, rovers, and EVA assistants will be limited. The third power system concept now being considered are fuel cell based systems. Fuel cell power systems overcome many of the performance and surface exploration limitations of solar array/battery power systems and the prohibitive cost and other difficulties associated with nuclear power systems for mobile applications. In an effort to better understand the capabilities and limitations of fuel cell power systems for Moon and Mars exploration applications, NASA is investigating the use of in-Situ Resource Utilization (ISRU) produced reactant, fuel cell based power plants to power robotic outpost rovers, science equipment, and future human spacecraft, surface-excursion rovers, and EVA assistant rovers. This paper will briefly compare the capabilities and limitations of fuel cell power systems relative to solar array/battery and nuclear systems, discuss the unique and enhanced missions that fuel cell power systems enable, and discuss the common technology and system attributes

  19. Analysis and Test of a Proton Exchange Membrane Fuel Cell Power System for Space Power Applications

    NASA Technical Reports Server (NTRS)

    Vasquez, Arturo; Varanauski, Donald; Clark, Robert, Jr.

    2000-01-01

    An effort is underway to develop a prototype Proton Exchange Membrane (PEM) Fuel Cell breadboard system for fuhlre space applications. This prototype will be used to develop a comprehensive design basis for a space-rated PEM fuel cell powerplant. The prototype system includes reactant pressure regulators, ejector-based reactant pumps, a 4-kW fuel cell stack and cooling system, and a passive, membranebased oxygen / water separator. A computer model is being developed concurrently to analytically predict fluid flow in the oxidant reactant system. Fuel cells have historically played an important role in human-rated spacecraft. The Gemini and Apollo spacecraft used fuel cells for vehicle electrical power. The Space Shuttle currently uses three Alkaline Fuel Cell Powerplants (AFCP) to generate all of the vehicle's 15-20kW electrical power. Engineers at the Johnson Space Center have leveraged off the development effort ongoing in the commercial arena to develop PEM fuel cel ls for terrestrial uses. The prototype design originated from efforts to develop a PEM fuel cell replacement for the current Space Shuttle AFCP' s. In order to improve on the life and an already excellent hi storical record of reliability and safety, three subsystems were focused on. These were the fuel cell stack itself, the reactant circulation devices, and reactant / product water separator. PEM fuel cell stack performance is already demonstrating the potential for greater than four times the useful life of the current Shuttle's AFCP. Reactant pumping for product water removal has historically been accomplished with mechanical pumps. Ejectors offer an effective means of reactant pumping as well as the potential for weight reduction, control simplification, and long life. Centrifugal water separation is used on the current AFCP. A passive, membrane-based water separator offers compatibility with the micro-gravity environment of space, and the potential for control simplification, elimination of

  20. Current Fed Step-up DC/DC Converter for Fuel Cell Inverter Applications

    NASA Astrophysics Data System (ADS)

    Andreičiks, Aleksandrs; Vitols, Kristaps; Krievs, Oskars; Steiks, Ingars

    2009-01-01

    In order to use hydrogen fuel cells in domestic applications either as main power supply or backup source, their low DC output voltage has to be matched to the level and frequency of the utility grid AC voltage. Such power converter systems usually consist of a DC-DC converter and a DC-AC inverter. Comparison of different current fed step-up DC/DC converters is done in this paper and a double inductor step-up push-pull converter investigated, presenting simulation and experimental results. The converter is elaborated for 1200 W power to match the rated power of the proton exchange membrane (PEM) fuel cell located in hydrogen fuel cell research laboratory of Riga Technical University.

  1. Tunable high performance cross-linked alkaline anion exchange membranes for fuel cell applications.

    PubMed

    Robertson, Nicholas J; Kostalik, Henry A; Clark, Timothy J; Mutolo, Paul F; Abruña, Héctor D; Coates, Geoffrey W

    2010-03-17

    Fuel cells are energy conversion devices that show great potential in numerous applications ranging from automobiles to portable electronics. However, further development of fuel cell components is necessary for them to become commercially viable. One component critical to their performance is the polymer electrolyte membrane, which is an ion conductive medium separating the two electrodes. While proton conducting membranes are well established (e.g., Nafion), hydroxide conducting membranes (alkaline anion exchange membranes, AAEMs) have been relatively unexplored by comparison. Operating under alkaline conditions offers significant efficiency benefits, especially for the oxygen reduction reaction; therefore, effective AAEMs could significantly advance fuel cell technologies. Here we demonstrate the use of ring-opening metathesis polymerization to generate new cross-linked membrane materials exhibiting high hydroxide ion conductivity and good mechanical properties. Cross-linking allows for increased ion incorporation, which, in turn supports high conductivities. This facile synthetic approach enables the preparation of cross-linked materials with the potential to meet the demands of hydrogen-powered fuel cells as well as direct methanol fuel cells. PMID:20178312

  2. Tunable High Performance Cross-Linked Alkaline Anion Exchange Membranes for Fuel Cell Applications

    SciTech Connect

    Robertson, Nicholas J.; Kostalik, IV, Henry A.; Clark, Timothy J.; Mutolo, Paul F.; Abruña, Héctor D.; Coates, Geoffrey W.

    2010-02-23

    Fuel cells are energy conversion devices that show great potential in numerous applications ranging from automobiles to portable electronics. However, further development of fuel cell components is necessary for them to become commercially viable. One component critical to their performance is the polymer electrolyte membrane, which is an ion conductive medium separating the two electrodes. While proton conducting membranes are well established (e.g., Nafion), hydroxide conducting membranes (alkaline anion exchange membranes, AAEMs) have been relatively unexplored by comparison. Operating under alkaline conditions offers significant efficiency benefits, especially for the oxygen reduction reaction; therefore, effective AAEMs could significantly advance fuel cell technologies. Here we demonstrate the use of ring-opening metathesis polymerization to generate new cross-linked membrane materials exhibiting high hydroxide ion conductivity and good mechanical properties. Cross-linking allows for increased ion incorporation, which, in turn supports high conductivities. This facile synthetic approach enables the preparation of cross-linked materials with the potential to meet the demands of hydrogen-powered fuel cells as well as direct methanol fuel cells.

  3. Application of fuel cell for pyrite and heavy metal containing mining waste

    NASA Astrophysics Data System (ADS)

    Keum, H.; Ju, W. J.; Jho, E. H.; Nam, K.

    2015-12-01

    Once pyrite and heavy metal containing mining waste reacts with water and air it produces acid mine drainage (AMD) and leads to the other environmental problems such as contamination of surrounding soils. Pyrite is the major source of AMD and it can be controlled using a biological-electrochemical dissolution method. By enhancing the dissolution of pyrite using fuel cell technology, not only mining waste be beneficially utilized but also be treated at the same time by. As pyrite-containing mining waste is oxidized in the anode of the fuel cell, electrons and protons are generated, and electrons moves through an external load to cathode reducing oxygen to water while protons migrate to cathode through a proton exchange membrane. Iron-oxidizing bacteria such as Acidithiobacillus ferrooxidans, which can utilize Fe as an electron donor promotes pyrite dissolution and hence enhances electrochemical dissolution of pyrite from mining waste. In this study mining waste from a zinc mine in Korea containing 17 wt% pyrite and 9% As was utilized as a fuel for the fuel cell inoculated with A. ferrooxidans. Electrochemically dissolved As content and chemically dissolved As content was compared. With the initial pH of 3.5 at 23℃, the dissolved As concentration increased (from 4.0 to 13 mg/L after 20 d) in the fuel cell, while it kept decreased in the chemical reactor (from 12 to 0.43 mg/L after 20 d). The fuel cell produced 0.09 V of open circuit voltage with the maximum power density of 0.84 mW/m2. Dissolution of As from mining waste was enhanced through electrochemical reaction. Application of fuel cell technology is a novel treatment method for pyrite and heavy metals containing mining waste, and this method is beneficial for mining environment as well as local community of mining areas.

  4. Fuel Processors for PEM Fuel Cells

    SciTech Connect

    Levi T. Thompson

    2008-08-08

    Fuel cells are being developed to power cleaner, more fuel efficient automobiles. The fuel cell technology favored by many automobile manufacturers is PEM fuel cells operating with H2 from liquid fuels like gasoline and diesel. A key challenge to the commercialization of PEM fuel cell based powertrains is the lack of sufficiently small and inexpensive fuel processors. Improving the performance and cost of the fuel processor will require the development of better performing catalysts, new reactor designs and better integration of the various fuel processing components. These components and systems could also find use in natural gas fuel processing for stationary, distributed generation applications. Prototype fuel processors were produced, and evaluated against the Department of Energy technical targets. Significant advances were made by integrating low-cost microreactor systems, high activity catalysts, π-complexation adsorbents, and high efficiency microcombustor/microvaporizers developed at the University of Michigan. The microreactor system allowed (1) more efficient thermal coupling of the fuel processor operations thereby minimizing heat exchanger requirements, (2) improved catalyst performance due to optimal reactor temperature profiles and increased heat and mass transport rates, and (3) better cold-start and transient responses.

  5. Hydrogen Fueled Hybrid Solid Oxide Fuel Cell-Gas Turbine (SOFC-GT) System for Long-Haul Rail Application

    NASA Astrophysics Data System (ADS)

    Chow, Justin Jeff

    Freight movement of goods is the artery for America's economic health. Long-haul rail is the premier mode of transport on a ton-mile basis. Concerns regarding greenhouse gas and criteria pollutant emissions, however, have motivated the creation of annually increasing locomotive emissions standards. Health issues from diesel particulate matter, especially near rail yards, have also been on the rise. These factors and the potential to raise conventional diesel-electric locomotive performance warrants the investigation of using future fuels in a more efficient system for locomotive application. This research evaluates the dynamic performance of a Solid Oxide Fuel Cell-Gas Turbine (SOFC-GT) Hybrid system operating on hydrogen fuel to power a locomotive over a rail path starting from the Port of Los Angeles and ending in the City of Barstow. Physical constraints, representative locomotive operation logic, and basic design are used from a previous feasibility study and simulations are performed in the MATLAB Simulink environment. In-house controls are adapted to and expanded upon. Results indicate high fuel-to-electricity efficiencies of at least 54% compared to a conventional diesel-electric locomotive efficiency of 35%. Incorporation of properly calibrated feedback and feed-forward controls enables substantial load following of difficult transients that result from train kinematics while maintaining turbomachinery operating requirements and suppressing thermal stresses in the fuel cell stack. The power split between the SOFC and gas turbine is deduced to be a deterministic factor in the balance between capital and operational costs. Using hydrogen results in no emissions if renewable and offers a potential of 24.2% fuel energy savings for the rail industry.

  6. Analysis of H2 storage needs for early market non-motive fuel cell applications.

    SciTech Connect

    Johnson, Terry Alan; Moreno, Marcina; Arienti, Marco; Pratt, Joseph William; Shaw, Leo; Klebanoff, Leonard E.

    2012-03-01

    Hydrogen fuel cells can potentially reduce greenhouse gas emissions and the United States dependence on foreign oil, but issues with hydrogen storage are impeding their widespread use. To help overcome these challenges, this study analyzes opportunities for their near-term deployment in five categories of non-motive equipment: portable power, construction equipment, airport ground support equipment, telecom backup power, and man-portable power and personal electronics. To this end, researchers engaged end users, equipment manufacturers, and technical experts via workshops, interviews, and electronic means, and then compiled these data into meaningful and realistic requirements for hydrogen storage in specific target applications. In addition to developing these requirements, end-user benefits (e.g., low noise and emissions, high efficiency, potentially lower maintenance costs) and concerns (e.g., capital cost, hydrogen availability) of hydrogen fuel cells in these applications were identified. Market data show potential deployments vary with application from hundreds to hundreds of thousands of units.

  7. 1990 fuel cell seminar: Program and abstracts

    SciTech Connect

    Not Available

    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.

  8. A comparison of low-pressure and supercharged operation of polymer electrolyte membrane fuel cell systems for aircraft applications

    NASA Astrophysics Data System (ADS)

    Werner, C.; Preiß, G.; Gores, F.; Griebenow, M.; Heitmann, S.

    2016-08-01

    Multifunctional fuel cell systems are competitive solutions aboard future generations of civil aircraft concerning energy consumption, environmental issues, and safety reasons. The present study compares low-pressure and supercharged operation of polymer electrolyte membrane fuel cells with respect to performance and efficiency criteria. This is motivated by the challenge of pressure-dependent fuel cell operation aboard aircraft with cabin pressure varying with operating altitude. Experimental investigations of low-pressure fuel cell operation use model-based design of experiments and are complemented by numerical investigations concerning supercharged fuel cell operation. It is demonstrated that a low-pressure operation is feasible with the fuel cell device under test, but that its range of stable operation changes between both operating modes. Including an external compressor, it can be shown that the power demand for supercharging the fuel cell is about the same as the loss in power output of the fuel cell due to low-pressure operation. Furthermore, the supercharged fuel cell operation appears to be more sensitive with respect to variations in the considered independent operating parameters load requirement, cathode stoichiometric ratio, and cooling temperature. The results indicate that a pressure-dependent self-humidification control might be able to exploit the potential of low-pressure fuel cell operation for aircraft applications to the best advantage.

  9. Development of planar solid oxide fuel cells for power generation applications

    SciTech Connect

    Minh, N.Q.

    1996-04-01

    Planar solid oxide fuel cells (SOFCs) are presently being developed for a variety of electric power generation application. The planar design offers simple cell geometry, high power density, and multiple fabrication and gas manifolding options. Planar SOFC technology has received much attention recently, and significant progress has been made in this area. Recent effort at AlliedSignal has focused on the development of high-performance, lightweight planar SOFCs, having thin-electrolyte films, that can be operated efficiently at reduced temperatures (< 1000{degrees}C). The advantages of reduced-temperature operation include wider material choice (including use of metallic interconnects), expected longer cell life, reduced thermal stress, improved reliability, and reduced fuel cell cost. The key aspect in the development of thin-film SIFCs is to incorporate the thin electrolyte layer into the desired structure of cells in a manner that yields the required characteristics. AlliedSignal has developed a simple and cost-effective method based on tape calendering for the fabrication of thin-electrolyte SOFCs. Thin-electrolyte cells made by tape calendering have shown extraordinary performance, e.g., producing more than 500mW/cm{sup 2} at 700{degrees}C and 800mW/cm{sup 2} at 800{degrees}C with hydrogen as fuel and air is oxidant. thin-electrolyte single cells have been incorporated into a compliant metallic stack structure and operated at reduced and operated at reduced-temperature conditions.

  10. Hydrogen peroxide oxidant fuel cell systems for ultra-portable applications

    NASA Technical Reports Server (NTRS)

    Valdez, T. I.; Narayanan, S. R.

    2001-01-01

    This paper will address the issues of using hydrogen peroxide as an oxidant fuel in a miniature DMFC system. Cell performance for DMFC based fuel cells operating on hydrogen peroxide will be presented and discussed.

  11. Fuel Cell Handbook, Fourth Edition

    SciTech Connect

    Stauffer, D.B; Hirschenhofer, J.H.; Klett, M.G.; Engleman, R.R.

    1998-11-01

    Robust progress has been made in fuel cell technology since the previous edition of the Fuel Cell Handbook was published in January 1994. 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 ultra high 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 6 describe the four major fuel cell types and their performance based on cell operating conditions. The section on polymer electrolyte membrane fuel cells has been added to reflect their emergence as a significant fuel cell technology. Phosphoric acid, molten carbonate, and solid oxide fuel cell technology description sections have been updated from the previous edition. New information indicates that manufacturers have stayed with proven cell designs, focusing instead on advancing the system surrounding the fuel cell to lower life cycle costs. Section 7, Fuel Cell Systems, has been significantly revised to characterize near-term and next-generation fuel cell power plant systems at a conceptual level of detail. Section 8 provides examples of practical fuel cell system calculations. A list of fuel cell URLs is included in the Appendix. A new index assists the reader in locating specific information quickly.

  12. Synthesization of SnO2-modified carbon nanotubes and their application in microbial fuel cell

    NASA Astrophysics Data System (ADS)

    Wang, Zi-Bo; Xiong, Shi-Chang; Guan, Yu-Jiang; Zhu, Xue-Qiang

    2016-03-01

    The aim of this work was to study the synthesization of SnO2-modified carbon nanotubes and their application in microbial fuel cell. With the chemical vapor deposition technique, carbon nanotubes growing in situ on a carbon felt are obtained. A SnO2 sol was applied to the carbon felt to prepare a SnO2-modified carbon nanotubes. X-ray diffraction and energy-dispersive X-ray analysis confirmed that SnO2 existed in the prepared samples. Using the prepared samples as anode electrodes, flexible graphite as cathode, and glucose solution as substrate in microbial fuel cell, the effects of the temperature, substrate concentration, and electrodes on removal rates for chemical oxygen demand and the performance of microbial fuel cell have been analyzed. With substrate concentration of 1500 mg L-1, the microbial fuel cell had an optimal output voltage of 563 mV and a removal rate of 78 % for chemical oxygen demand at 311 K. The composite electrodes are stable and reusable.

  13. Center for Fuel Cell Research and Applications development phase. Final report

    SciTech Connect

    1998-12-01

    The deployment and operation of clean power generation is becoming critical as the energy and transportation sectors seek ways to comply with clean air standards and the national deregulation of the utility industry. However, for strategic business decisions, considerable analysis is required over the next few years to evaluate the appropriate application and value added from this emerging technology. To this end the Houston Advanced Research Center (HARC) is proposing a three-year industry-driven project that centers on the creation of ``The Center for Fuel Cell Research and Applications.`` A collaborative laboratory housed at and managed by HARC, the Center will enable a core group of six diverse participating companies--industry participants--to investigate the economic and operational feasibility of proton-exchange-membrane (PEM) fuel cells in a variety of applications (the core project). This document describes the unique benefits of a collaborative approach to PEM applied research, among them a shared laboratory concept leading to cost savings and shared risks as well as access to outstanding research talent and lab facilities. It also describes the benefits provided by implementing the project at HARC, with particular emphasis on HARC`s history of managing successful long-term research projects as well as its experience in dealing with industry consortia projects. The Center is also unique in that it will not duplicate the traditional university role of basic research or that of the fuel cell industry in developing commercial products. Instead, the Center will focus on applications, testing, and demonstration of fuel cell technology.

  14. Fuel Cell Handbook, Fifth Edition

    SciTech Connect

    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

  15. Power management systems for sediment microbial fuel cells in high power and continuous power applications

    NASA Astrophysics Data System (ADS)

    Donovan, Conrad Koble

    The objective of this dissertation was to develop power management systems (PMS) for sediment microbial fuel cells (SFMCs) for high power and continuous applications. The first part of this dissertation covers a new method for testing the performance of SMFCs. This device called the microbial fuel cell tester was developed to automatically test power generation of PMS. The second part focuses on a PMS capable of delivering high power in burst mode. This means that for a small amount of time a large amount of power up to 2.5 Watts can be delivered from a SMFC only generating mW level power. The third part is aimed at developing a multi-potentiostat laboratory tool that measures the performance at fixed cell potentials of microbial fuel cells so that I can optimize them for use with the PMS. This tool is capable of controlling the anode potential or cathode potential and measuring current of six separate SMFCs simultaneously. By operating multiple potentiostats, I was able to run experiments that find ideal operating conditions for the sediment microbial fuel cells, and also I can optimize the power management system for these conditions. The fourth part of the dissertation is targeting a PMS that was able to operate a sensor continuously which was powered by an SMFC. In pervious applications involving SMFCs, the PMS operated in batch mode. In this PMS, the firmware on the submersible ultrasonic receiver (SUR) was modified for use with my PMS. This integration of PMS and SUR allowed for the continuous operation of the SUR without using a battery. Finally, the last part of the dissertation recommends a scale-up power management system to overcome the linearity scale up issue of SMFCs as future work. Concluding remarks are also added to summarize the goal and focus of this dissertation.

  16. Fuel cells for vehicle applications in cars - bringing the future closer

    NASA Astrophysics Data System (ADS)

    Panik, Ferdinand

    Among all alternative drive systems, the fuel cell electric propulsion system has the highest potential to compete with the internal combustion engine. For this reason, Daimler-Benz AG has entered into a co-operative alliance with Ballard Power Systems, with the objectives of bringing fuel cell vehicles to the market. Apart from the fuel cell itself, fuel cell vehicles require comprehensive system technology to provide fuel and air supply, cooling, energy management, electric and electronic functions. The system technology determines to a large extent the cost, weight, efficiency, performance and overall customer benefit of fuel cell vehicles. Hence, Daimler-Benz and Ballard are pooling their expertise in fuel cell system technology in a joint company, with the aim of bringing their fuel cell vehicular systems to the stage of maturity required for market entry as early as possible. Hydrogen-fuelled zero-emission fuel cell transit `buses' will be the first market segment addressed, with an emphasis on the North American and European markets. The first buses are already scheduled for delivery to customers in late 1997. Since a liquid fuel like methanol is easier to handle in passenger cars, fuel reforming technologies are developed and will shortly be demonstrated in a prototype, as well. The presentation will cover concepts of fuel cell vehicles with an emphasis on system technology, the related testing procedures and results as well as an outline of market entry strategies.

  17. Core-shell Au-Pd nanoparticles as cathode catalysts for microbial fuel cell applications

    NASA Astrophysics Data System (ADS)

    Yang, Gaixiu; Chen, Dong; Lv, Pengmei; Kong, Xiaoying; Sun, Yongming; Wang, Zhongming; Yuan, Zhenhong; Liu, Hui; Yang, Jun

    2016-10-01

    Bimetallic nanoparticles with core-shell structures usually display enhanced catalytic properties due to the lattice strain created between the core and shell regions. In this study, we demonstrate the application of bimetallic Au-Pd nanoparticles with an Au core and a thin Pd shell as cathode catalysts in microbial fuel cells, which represent a promising technology for wastewater treatment, while directly generating electrical energy. In specific, in comparison with the hollow structured Pt nanoparticles, a benchmark for the electrocatalysis, the bimetallic core-shell Au-Pd nanoparticles are found to have superior activity and stability for oxygen reduction reaction in a neutral condition due to the strong electronic interaction and lattice strain effect between the Au core and the Pd shell domains. The maximum power density generated in a membraneless single-chamber microbial fuel cell running on wastewater with core-shell Au-Pd as cathode catalysts is ca. 16.0 W m‑3 and remains stable over 150 days, clearly illustrating the potential of core-shell nanostructures in the applications of microbial fuel cells.

  18. Core-shell Au-Pd nanoparticles as cathode catalysts for microbial fuel cell applications

    PubMed Central

    Yang, Gaixiu; Chen, Dong; Lv, Pengmei; Kong, Xiaoying; Sun, Yongming; Wang, Zhongming; Yuan, Zhenhong; Liu, Hui; Yang, Jun

    2016-01-01

    Bimetallic nanoparticles with core-shell structures usually display enhanced catalytic properties due to the lattice strain created between the core and shell regions. In this study, we demonstrate the application of bimetallic Au-Pd nanoparticles with an Au core and a thin Pd shell as cathode catalysts in microbial fuel cells, which represent a promising technology for wastewater treatment, while directly generating electrical energy. In specific, in comparison with the hollow structured Pt nanoparticles, a benchmark for the electrocatalysis, the bimetallic core-shell Au-Pd nanoparticles are found to have superior activity and stability for oxygen reduction reaction in a neutral condition due to the strong electronic interaction and lattice strain effect between the Au core and the Pd shell domains. The maximum power density generated in a membraneless single-chamber microbial fuel cell running on wastewater with core-shell Au-Pd as cathode catalysts is ca. 16.0 W m−3 and remains stable over 150 days, clearly illustrating the potential of core-shell nanostructures in the applications of microbial fuel cells. PMID:27734945

  19. Study of fuel cell on-site, integrated energy systems in residential/commercial applications

    NASA Technical Reports Server (NTRS)

    Wakefield, R. A.; Karamchetty, S.; Rand, R. H.; Ku, W. S.; Tekumalla, V.

    1980-01-01

    Three building applications were selected for a detailed study: a low rise apartment building; a retail store, and a hospital. Building design data were then specified for each application, based on the design and construction of typical, actual buildings. Finally, a computerized building loads analysis program was used to estimate hourly end use load profiles for each building. Conventional and fuel cell based energy systems were designed and simulated for each building in each location. Based on the results of a computer simulation of each energy system, levelized annual costs and annual energy consumptions were calculated for all systems.

  20. ARPA advanced fuel cell development

    SciTech Connect

    Dubois, L.H.

    1995-08-01

    Fuel cell technology is currently being developed at the Advanced Research Projects Agency (ARPA) for several Department of Defense applications where its inherent advantages such as environmental compatibility, high efficiency, and low noise and vibration are overwhelmingly important. These applications range from man-portable power systems of only a few watts output (e.g., for microclimate cooling and as direct battery replacements) to multimegawatt fixed base systems. The ultimate goal of the ARPA program is to develop an efficient, low-temperature fuel cell power system that operates directly on a military logistics fuel (e.g., DF-2 or JP-8). The absence of a fuel reformer will reduce the size, weight, cost, and complexity of such a unit as well as increase its reliability. In order to reach this goal, ARPA is taking a two-fold, intermediate time-frame approach to: (1) develop a viable, low-temperature proton exchange membrane (PEM) fuel cell that operates directly on a simple hydrocarbon fuel (e.g., methanol or trimethoxymethane) and (2) demonstrate a thermally integrated fuel processor/fuel cell power system operating on a military logistics fuel. This latter program involves solid oxide (SOFC), molten carbonate (MCFC), and phosphoric acid (PAFC) fuel cell technologies and concentrates on the development of efficient fuel processors, impurity scrubbers, and systems integration. A complementary program to develop high performance, light weight H{sub 2}/air PEM and SOFC fuel cell stacks is also underway. Several recent successes of these programs will be highlighted.

  1. Nanostructure-based proton exchange membrane for fuel cell applications at high temperature.

    PubMed

    Li, Junsheng; Wang, Zhengbang; Li, Junrui; Pan, Mu; Tang, Haolin

    2014-02-01

    As a clean and highly efficient energy source, the proton exchange membrane fuel cell (PEMFC) has been considered an ideal alternative to traditional fossil energy sources. Great efforts have been devoted to realizing the commercialization of the PEMFC in the past decade. To eliminate some technical problems that are associated with the low-temperature operation (such as catalyst poisoning and poor water management), PEMFCs are usually operated at elevated temperatures (e.g., > 100 degrees C). However, traditional proton exchange membrane (PEM) shows poor performance at elevated temperature. To achieve a high-performance PEM for high temperature fuel cell applications, novel PEMs, which are based on nanostructures, have been developed recently. In this review, we discuss and summarize the methods for fabricating the nanostructure-based PEMs for PEMFC operated at elevated temperatures and the high temperature performance of these PEMs. We also give an outlook on the rational design and development of the nanostructure-based PEMs.

  2. Development of a polymer fuel cell system for naval surface ship applications

    SciTech Connect

    Schmal, D.; Kluiters, C.E.; Barendregt, I.P.

    1996-12-31

    In the framework of the development of new generations of surface ships, the Royal Netherlands Navy is studying the option of the all-electric ship concept. Background is the growing demand of electric power on board of naval ships for various services (including weapons and sensors). Important features of such an all-electric ship concept are decentralized electric energy generation and storage. In such an all-electric ship concept, fuel cells are expected to play an important role in the future, not only for reasons of energy efficiency and low emissions, but also because of their potential military advantages. Especially polymer electrolyte fuel cell systems appear to be very interesting for this application.

  3. Multiplex lithography for multilevel multiscale architectures and its application to polymer electrolyte membrane fuel cell

    PubMed Central

    Cho, Hyesung; Moon Kim, Sang; Sik Kang, Yun; Kim, Junsoo; Jang, Segeun; Kim, Minhyoung; Park, Hyunchul; Won Bang, Jung; Seo, Soonmin; Suh, Kahp-Yang; Sung, Yung-Eun; Choi, Mansoo

    2015-01-01

    The production of multiscale architectures is of significant interest in materials science, and the integration of those structures could provide a breakthrough for various applications. Here we report a simple yet versatile strategy that allows for the LEGO-like integrations of microscale membranes by quantitatively controlling the oxygen inhibition effects of ultraviolet-curable materials, leading to multilevel multiscale architectures. The spatial control of oxygen concentration induces different curing contrasts in a resin allowing the selective imprinting and bonding at different sides of a membrane, which enables LEGO-like integration together with the multiscale pattern formation. Utilizing the method, the multilevel multiscale Nafion membranes are prepared and applied to polymer electrolyte membrane fuel cell. Our multiscale membrane fuel cell demonstrates significant enhancement of performance while ensuring mechanical robustness. The performance enhancement is caused by the combined effect of the decrease of membrane resistance and the increase of the electrochemical active surface area. PMID:26412619

  4. Assembly of a Cost-Effective Anode Using Palladium Nanoparticles for Alkaline Fuel Cell Applications

    PubMed Central

    2015-01-01

    Nanotechnology allows the synthesis of nanoscale catalysts, which offer an efficient alternative for fuel cell applications. In this laboratory experiment, the student selects a cost-effective anode for fuel cells by comparing three different working electrodes. These are commercially available palladium (Pd) and glassy carbon (GC) electrodes, and a carbon paste (CP) electrode that is prepared by the students in the laboratory. The GC and CP were modified with palladium nanoparticles (PdNP) suspensions. The electrodes efficiencies were studied for ethanol oxidation in alkaline solution using cyclic voltammetry techniques. The ethanol oxidation currents obtained were used to determine the current density using the geometric and surface area of each electrode. Finally, students were able to choose the best electrode and relate catalytic activity to surface area for ethanol oxidation in alkaline solution by completing a critical analysis of the cyclic voltammetry results. With this activity, fundamental electrochemical concepts were reinforced. PMID:25691801

  5. Fabrication of Yttria stabilized zirconia thin films on poroussubstrates for fuel cell applications

    SciTech Connect

    Leming, Andres

    2003-06-16

    A process for the deposition of yttria stabilized zirconia (YSZ) films, on porous substrates, has been developed. These films have possible applications as electrolyte membranes in fuel cells. The films were deposited from colloidal suspensions through the vacuum infiltration technique. Films were deposited on both fully sintered and partially sintered substrates. A critical cracking thickness for the films was identified and strategies are presented to overcome this barrier. Green film density was also examined, and a method for improving green density by changing suspension pH and surfactant was developed. A dependence of film density on film thickness was observed, and materials interactions are suggested as a possible cause. Non-shorted YSZ films were obtained on co-fired substrates, and a cathode supported solid oxide fuel cell was constructed and characterized.

  6. A review on synthesis and characterization of solid acid materials for fuel cell applications

    NASA Astrophysics Data System (ADS)

    Mohammad, Norsyahida; Mohamad, Abu Bakar; Kadhum, Abdul Amir H.; Loh, Kee Shyuan

    2016-08-01

    Solid acids emerged as an electrolyte material for application in fuel cells due to their high protonic conductivity and stability at high temperatures between 100 °C and 250 °C. This paper gives an overview of the different solid acid materials and their properties, such as high protonic conductivity and thermal stability, in relation to phase transitions and mechanisms of proton transport. Various solid acid synthesis methods including aqueous and dry mixing, electrospinning, sol-gel, impregnation and thin-film casting will be discussed, and the impact of synthesis methods on the properties of solid acids will be highlighted. The properties of solid acids synthesized as either single crystals and or polycrystalline powders were identified via X-ray diffraction, nuclear magnetic resonance, thermal analyses, optical microscopy and infrared spectroscopy. A selection of electrolyte-electrode assembly methods and the performance of solid acid fuel cell prototypes are also reviewed.

  7. Study of metallic materials for solid oxide fuel cell interconnect applications.

    SciTech Connect

    Natesan, K.; Zeng, Z.; Nuclear Engineering Division

    2009-04-24

    Metallic interconnect acts as a gas separator and a gas distributor and therefore, it needs to function adequately in two widely different environments. The interconnect material will be exposed to air on one side and natural gas or coal-derived synthesis gas on the other side. The viable material for the interconnect application must be resistant not only to oxidation but also carburization in hydrocarbon containing low-oxygen environments. In addition, the scales that develop on the exposed surfaces must possess adequate electrical conductivity for them to function as current leads over long service life of the fuel cell. This report addresses five topics of interest for the development of metallic interconnects with adequate performance in fuel cells for long service life. The research conducted over the years and the conclusions reached were used to identify additional areas of research on materials for improved performance of components, especially metallic interconnects, in the complex fuel cell environments. This report details research conducted in the following areas: measurement of area specific electrical resistivity, corrosion performance in dual gas environments by experiments using alloy 446, long term corrosion performance of ferritic and austenitic alloys in hydrogen and methane-reformed synthesis fuel-gas environments, approaches to reduce the area resistance of metallic interconnect, and reduction of electrical resistivity of alumina scales on metallic interconnect. Based on the key requirements for metallic interconnects and the data developed on the corrosion behavior of candidate materials in meeting those requirements, several areas are recommended for further research to develop metallic interconnects with acceptable and reliable long-term performance in solid oxide fuel cells.

  8. Conceptual design report for a Direct Hydrogen Proton Exchange Membrane Fuel Cell for transportation application

    SciTech Connect

    1995-09-05

    This report presents the conceptual design for a Direct-Hydrogen-Fueled Proton Exchange Membrane (PEM) Fuel Cell System for transportation applications. The design is based on the initial selection of the Chrysler LH sedan as the target vehicle with a 50 kW (gross) PEM Fuel Cell Stack (FCS) as the primary power source, a battery-powered Load Leveling Unit (LLU) for surge power requirements, an on-board hydrogen storage subsystem containing high pressure gaseous storage, a Gas Management Subsystem (GMS) to manage the hydrogen and air supplies for the FCS, and electronic controllers to control the electrical system. The design process has been dedicated to the use of Design-to-Cost (DTC) principles. The Direct Hydrogen-Powered PEM Fuel Cell Stack Hybrid Vehicle (DPHV) system is designed to operate on the Federal Urban Driving Schedule (FUDS) and Hiway Cycles. These cycles have been used to evaluate the vehicle performance with regard to range and hydrogen usage. The major constraints for the DPHV vehicle are vehicle and battery weight, transparency of the power system and drive train to the user, equivalence of fuel and life cycle costs to conventional vehicles, and vehicle range. The energy and power requirements are derived by the capability of the DPHV system to achieve an acceleration from 0 to 60 MPH within 12 seconds, and the capability to achieve and maintain a speed of 55 MPH on a grade of seven percent. The conceptual design for the DPHV vehicle is shown in a figure. A detailed description of the Hydrogen Storage Subsystem is given in section 4. A detailed description of the FCS Subsystem and GMS is given in section 3. A detailed description of the LLU, selection of the LLU energy source, and the power controller designs is given in section 5.

  9. Application of green chemistry techniques to prepare electrocatalysts for direct methanol fuel cells.

    PubMed

    Shimizu, Kenichi; Wang, Joanna S; Wai, Chien M

    2010-03-25

    A series of green techniques for synthesizing carbon nanotube-supported platinum nanoparticles and their high electrocatalytic activity toward methanol fuel cell applications are reported. The techniques utilize either the supercritical fluid carbon dioxide or water as a medium for depositing platinum nanoparticles on surfaces of multiwalled or single-walled carbon nanotubes. The catalytic properties of the carbon nanotubes-supported Pt nanoparticle catalysts prepared by four different techniques are compared for anodic oxidation of methanol and cathodic reduction of oxygen using cyclic voltammetry. One technique using galvanic exchange of Pt(2+) in water with zerovalent iron present on the surfaces of as-grown single-walled carbon nanotubes produces a Pt catalyst that shows an unusually high catalytic activity for reduction of oxygen but a negligible activity for oxidation of methanol. This fuel-selective catalyst may have a unique application as a cathode catalyst in methanol fuel cells to alleviate the problems caused by crossover of methanol through the polymer electrolyte membrane. PMID:19827801

  10. Application of green chemistry techniques to prepare electrocatalysts for direct methanol fuel cells.

    PubMed

    Shimizu, Kenichi; Wang, Joanna S; Wai, Chien M

    2010-03-25

    A series of green techniques for synthesizing carbon nanotube-supported platinum nanoparticles and their high electrocatalytic activity toward methanol fuel cell applications are reported. The techniques utilize either the supercritical fluid carbon dioxide or water as a medium for depositing platinum nanoparticles on surfaces of multiwalled or single-walled carbon nanotubes. The catalytic properties of the carbon nanotubes-supported Pt nanoparticle catalysts prepared by four different techniques are compared for anodic oxidation of methanol and cathodic reduction of oxygen using cyclic voltammetry. One technique using galvanic exchange of Pt(2+) in water with zerovalent iron present on the surfaces of as-grown single-walled carbon nanotubes produces a Pt catalyst that shows an unusually high catalytic activity for reduction of oxygen but a negligible activity for oxidation of methanol. This fuel-selective catalyst may have a unique application as a cathode catalyst in methanol fuel cells to alleviate the problems caused by crossover of methanol through the polymer electrolyte membrane.

  11. Facile and Gram-scale Synthesis of Metal-free Catalysts: Toward Realistic Applications for Fuel Cells

    PubMed Central

    Kim, Ok-Hee; Cho, Yong-Hun; Chung, Dong Young; Kim, Min Jeong; Yoo, Ji Mun; Park, Ji Eun; Choe, Heeman; Sung, Yung-Eun

    2015-01-01

    Although numerous reports on nonprecious metal catalysts for replacing expensive Pt-based catalysts have been published, few of these studies have demonstrated their practical application in fuel cells. In this work, we report graphitic carbon nitride and carbon nanofiber hybrid materials synthesized by a facile and gram-scale method via liquid-based reactions, without the use of toxic materials or a high pressure-high temperature reactor, for use as fuel cell cathodes. The resulting materials exhibited remarkable methanol tolerance, selectivity, and stability even without a metal dopant. Furthermore, these completely metal-free catalysts exhibited outstanding performance as cathode materials in an actual fuel cell device: a membrane electrode assembly with both acidic and alkaline polymer electrolytes. The fabrication method and remarkable performance of the single cell produced in this study represent progressive steps toward the realistic application of metal-free cathode electrocatalysts in fuel cells. PMID:25728910

  12. Facile and Gram-scale Synthesis of Metal-free Catalysts: Toward Realistic Applications for Fuel Cells

    NASA Astrophysics Data System (ADS)

    Kim, Ok-Hee; Cho, Yong-Hun; Chung, Dong Young; Kim, Min Jeong; Yoo, Ji Mun; Park, Ji Eun; Choe, Heeman; Sung, Yung-Eun

    2015-03-01

    Although numerous reports on nonprecious metal catalysts for replacing expensive Pt-based catalysts have been published, few of these studies have demonstrated their practical application in fuel cells. In this work, we report graphitic carbon nitride and carbon nanofiber hybrid materials synthesized by a facile and gram-scale method via liquid-based reactions, without the use of toxic materials or a high pressure-high temperature reactor, for use as fuel cell cathodes. The resulting materials exhibited remarkable methanol tolerance, selectivity, and stability even without a metal dopant. Furthermore, these completely metal-free catalysts exhibited outstanding performance as cathode materials in an actual fuel cell device: a membrane electrode assembly with both acidic and alkaline polymer electrolytes. The fabrication method and remarkable performance of the single cell produced in this study represent progressive steps toward the realistic application of metal-free cathode electrocatalysts in fuel cells.

  13. Facile and gram-scale synthesis of metal-free catalysts: toward realistic applications for fuel cells.

    PubMed

    Kim, Ok-Hee; Cho, Yong-Hun; Chung, Dong Young; Kim, Min Jeong; Yoo, Ji Mun; Park, Ji Eun; Choe, Heeman; Sung, Yung-Eun

    2015-03-02

    Although numerous reports on nonprecious metal catalysts for replacing expensive Pt-based catalysts have been published, few of these studies have demonstrated their practical application in fuel cells. In this work, we report graphitic carbon nitride and carbon nanofiber hybrid materials synthesized by a facile and gram-scale method via liquid-based reactions, without the use of toxic materials or a high pressure-high temperature reactor, for use as fuel cell cathodes. The resulting materials exhibited remarkable methanol tolerance, selectivity, and stability even without a metal dopant. Furthermore, these completely metal-free catalysts exhibited outstanding performance as cathode materials in an actual fuel cell device: a membrane electrode assembly with both acidic and alkaline polymer electrolytes. The fabrication method and remarkable performance of the single cell produced in this study represent progressive steps toward the realistic application of metal-free cathode electrocatalysts in fuel cells.

  14. Aircraft Fuel Cell Power Systems

    NASA Technical Reports Server (NTRS)

    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

  15. Graphene/Nickel Nanofiber Hybrids for Catalytic and Microbial Fuel Cell Applications.

    PubMed

    Kartick, B; Srivastava, S K; Chandra, A

    2016-01-01

    The present work deals with the preparation of fcc-nickel (Ni) nanofibers and Graphene/Ni hybrids. The analysis of XRD, FTIR and Raman data confirms the formation of pure Ni, graphite oxide, reduced graphene and their hybrids. SEM micrographs clearly show the decoration of Ni nanofibers on the graphene flakes. The synthesized Ni-based hybrid systems can have applications in areas ranging from: magnetism, catalysis to microbial fuel cells. The vibrating sample magnetometer (VSM) investigations reveal that the hybrid structure shows hysteresis loop similar to that expected from a superparamagnetic system. When the same hybrid structure is used as catalyst for decolourization of 4-nitrophenol, the maximum rate constant of 0.1 min⁻¹ can be obtained. The catalytic activity also shows dependence on the loading concentration of Ni. The enhanced performance can be explained on the basis of synergistic effect between graphene and nickel nanofibers. The developed hybrids have also been applied as catalyst for cathode in microbial fuel cells and the studies showed improved power density compared to conventional microbial fuel cells (MFCs). PMID:27398458

  16. Analytical Investigation and Improvement of Performance of a Proton Exchange Membrane (Pem) Fuel Cell in Mobile Applications

    NASA Astrophysics Data System (ADS)

    Khazaee, I.

    2015-05-01

    In this study, the performance of a proton exchange membrane fuel cell in mobile applications is investigated analytically. At present the main use and advantages of fuel cells impact particularly strongly on mobile applications such as vehicles, mobile computers and mobile telephones. Some external parameters such as the cell temperature (Tcell ) , operating pressure of gases (P) and air stoichiometry (λair ) affect the performance and voltage losses in the PEM fuel cell. Because of the existence of many theoretical, empirical and semi-empirical models of the PEM fuel cell, it is necessary to compare the accuracy of these models. But theoretical models that are obtained from thermodynamic and electrochemical approach, are very exact but complex, so it would be easier to use the empirical and smi-empirical models in order to forecast the fuel cell system performance in many applications such as mobile applications. The main purpose of this study is to obtain the semi-empirical relation of a PEM fuel cell with the least voltage losses. Also, the results are compared with the existing experimental results in the literature and a good agreement is seen.

  17. Fuel Cell Seminar, 1992: Program and abstracts

    SciTech Connect

    Not Available

    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.

  18. Fuel Cell Seminar, 1992: Program and abstracts

    NASA Astrophysics Data System (ADS)

    1992-03-01

    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.

  19. Research and development of proton-exchange membrane (PEM) fuel cell system for transportation applications. Phase I final report

    SciTech Connect

    1996-01-01

    Objective during Phase I was to develop a methanol-fueled 10-kW fuel cell power source and evaluate its feasibility for transportation applications. This report documents research on component (fuel cell stack, fuel processor, power source ancillaries and system sensors) development and the 10-kW power source system integration and test. The conceptual design study for a PEM fuel cell powered vehicle was documented in an earlier report (DOE/CH/10435-01) and is summarized herein. Major achievements in the program include development of advanced membrane and thin-film low Pt-loaded electrode assemblies that in reference cell testing with reformate-air reactants yielded performance exceeding the program target (0.7 V at 1000 amps/ft{sup 2}); identification of oxidation catalysts and operating conditions that routinely result in very low CO levels ({le} 10 ppm) in the fuel processor reformate, thus avoiding degradation of the fuel cell stack performance; and successful integrated operation of a 10-kW fuel cell stack on reformate from the fuel processor.

  20. Development of 50 kW Fuel Processor for Stationary Fuel Cell Applications

    SciTech Connect

    James F. Stevens; Balaji Krishnamurthy; Paolina Atanassova; Kerry Spilker

    2007-08-29

    The objective of the project was to develop and test a fuel processor capable of producing high hydrogen concentration (>98%) with less than ppm quantities of carbon dioxide and carbon monoxide at lower capital cost and higher efficiency, compared to conventional natural gas reformers. It was intended that we achieve our objective by developing simple reactor/process design, and high durability CO2 absorbents, to replace pressure swing adsorption (PSA) or membrane separators. Cost analysis indicated that we would not meet DOE cost goals so the project was terminated before construction of the full scale fuel processor. The work on adsorbent development was focused on the development of calcium oxide-based reversible CO2 absorbents with various microstructures and morphologies to determine the optimum microstructure for long-term reversible CO2 absorption. The effect of powder production process variables was systematically studied including: the final target compositions, the reagents from which the final products were derived, the pore forming additives, the processing time and temperature. The sorbent materials were characterized in terms of their performance in the reversible reaction with CO2 and correlation made to their microstructure.

  1. Characterization and development of a new ceramic electrolyte for fuel cell applications

    NASA Astrophysics Data System (ADS)

    1991-06-01

    This work consisted of research directed toward characterization and development of new solid electrolyte materials that are potentially superior to other solid electrolyte materials currently under development (such as yttria-stabilized zirconia). The solid electrolyte technology described herein is based on new ceramic materials generally described as bismuth oxide doped with niobium or yttrium oxides that were exclusively licensed to Solid-State Fuel Cells, Inc. by CeramPhysics, Inc. The technology is also based on further material, cell, and stack technology concepts and manufacturing methods that were earlier reduced to practice by Solid State Fuel Cells, Inc., and which are, therefore, proprietary to the Company. In this report, a presentation of the overall program background is provided in Section 2.0. This includes a technical discussion of the technology in the context of the current state of the art. The task work description for the applicable portion of Phase 1 is presented in Section 3.0. Specifically, Phase 1-A comprises the following elements: electrolyte materials development; testing of electrolyte stability under a reducing environment; development of cell electrodes; test fixtures design and facility erection; and preliminary coupon cell tests.

  2. Evaluation of fuel-cell technology for Coast Guard applications. Final report

    SciTech Connect

    Barrett, T.J.

    1988-10-01

    Recent proposals and the literature show promise of fuel cells being commercially available in the next decade. We searched the literature to determine the current state of fuel-cell technology, to determine if fuel cells can be used by the U.S. Coast Guard, and to make proposals for possible research and development efforts by the Coast Guard. Alkaline and phosphoric acid fuel cell technologies are now technically capable of full scale commercial production. Molten-carbonate and solid-oxide fuel-cell technologies should be commercially produced within the next decade. Phosphoric Acid Fuel Cell (PAFC) technology is the most promising for Coast Guard use. However, there is no operational need for fuel cells at present and high capital costs and low-energy prices make them economically noncompetitive. We suggest three areas of R D to prepare for changes in operational needs or energy economics. They are: operation of a 200-kW PAFC cogeneration plant to gain fuel-cell experience; development of low-maintenance/high availability PAFC system for remote power; and development of fuel cells for or aircraft propulsion in case there is a strategic crisis in petroleum-distillate supplies.

  3. Fuel cells feasibility

    NASA Technical Reports Server (NTRS)

    Schonfeld, D.; Charng, T.

    1981-01-01

    The technical and economic status of fuel cells is assessed with emphasis on their potential benefits to the Deep Space Network. The fuel cell, what it is, how it operates, and what its outputs are, is reviewed. Major technical problems of the fuel cell and its components are highlighted. Due to these problems and economic considerations it is concluded that fuel cells will not become commercially viable until the early 1990s.

  4. Development of an advanced bond coat for solid oxide fuel cell interconnector applications

    NASA Astrophysics Data System (ADS)

    Yeh, An-Chou; Chen, Yu-Ming; Liu, Chien-Kuo; Shong, Wei-Ja

    2015-11-01

    An advanced bond coat has been developed for solid oxide fuel cell interconnector applications; a low thermal expansion superalloy has been selected as the substrate, and the newly developed bond coat is applied between the substrate and the LSM top coat. The bond coat composition is designed to be near thermodynamic equilibrium with the substrate to minimize interdiffusion with the substrate while providing oxidation protection for the substrate. The bond coat exhibits good oxidation resistance, a low area specific resistance, and a low thermal expansion coefficient at 800 °C; experimental results indicate that interdiffusion between the bond coat and the substrate can be hindered.

  5. Regenerative Fuel Cell System Testbed Program for Government and Commercial Applications

    NASA Technical Reports Server (NTRS)

    1996-01-01

    NASA Lewis Research Center's Electrochemical Technology Branch has led a multiagency effort to design, fabricate, and operate a regenerative fuel cell (RFC) system testbed. Key objectives of this program are to evaluate, characterize, and demonstrate fully integrated RFC's for space, military, and commercial applications. The Lewis-led team is implementing the program through a unique international coalition that encompasses both Government and industry participants. Construction of the 25-kW RFC testbed at the NASA facility at Edwards Air Force Base was completed in January 1995, and the system has been operational since that time.

  6. Characterization of Polyethylene-Graft-Sulfonated Polyarylsulfone Proton Exchange Membranes for Direct Methanol Fuel Cell Applications.

    PubMed

    Kim, Hyung Kyu; Zhang, Gang; Nam, Changwoo; Chung, T C Mike

    2015-12-04

    This paper examines polymer film morphology and several important properties of polyethylene-graft-sulfonated polyarylene ether sulfone (PE-g-s-PAES) proton exchange membranes (PEMs) for direct methanol fuel cell applications. Due to the extreme surface energy differences between a semi-crystalline and hydrophobic PE backbone and several amorphous and hydrophilic s-PAES side chains, the PE-g-s-PAES membrane self-assembles into a unique morphology, with many proton conductive s-PAES channels embedded in the stable and tough PE matrix and a thin hydrophobic PE layer spontaneously formed on the membrane surfaces. In the bulk, these membranes show good mechanical properties (tensile strength >30 MPa, Young's modulus >1400 MPa) and low water swelling (λ < 15) even with high IEC >3 mmol/g in the s-PAES domains. On the surface, the thin hydrophobic and semi-crystalline PE layer shows some unusual barrier (protective) properties. In addition to exhibiting higher through-plane conductivity (up to 160 mS/cm) than in-plane conductivity, the PE surface layer minimizes methanol cross-over from anode to cathode with reduced fuel loss, and stops the HO• and HO₂• radicals, originally formed at the anode, entering into PEM matrix. Evidently, the thin PE surface layer provides a highly desirable protecting layer for PEMs to reduce fuel loss and increase chemical stability. Overall, the newly developed PE-g-s-PAES membranes offer a desirable set of PEM properties, including conductivity, selectivity, mechanical strength, stability, and cost-effectiveness for direct methanol fuel cell applications.

  7. Characterization of Polyethylene-Graft-Sulfonated Polyarylsulfone Proton Exchange Membranes for Direct Methanol Fuel Cell Applications

    PubMed Central

    Kim, Hyung Kyu; Zhang, Gang; Nam, Changwoo; Chung, T.C. Mike

    2015-01-01

    This paper examines polymer film morphology and several important properties of polyethylene-graft-sulfonated polyarylene ether sulfone (PE-g-s-PAES) proton exchange membranes (PEMs) for direct methanol fuel cell applications. Due to the extreme surface energy differences between a semi-crystalline and hydrophobic PE backbone and several amorphous and hydrophilic s-PAES side chains, the PE-g-s-PAES membrane self-assembles into a unique morphology, with many proton conductive s-PAES channels embedded in the stable and tough PE matrix and a thin hydrophobic PE layer spontaneously formed on the membrane surfaces. In the bulk, these membranes show good mechanical properties (tensile strength >30 MPa, Young’s modulus >1400 MPa) and low water swelling (λ < 15) even with high IEC >3 mmol/g in the s-PAES domains. On the surface, the thin hydrophobic and semi-crystalline PE layer shows some unusual barrier (protective) properties. In addition to exhibiting higher through-plane conductivity (up to 160 mS/cm) than in-plane conductivity, the PE surface layer minimizes methanol cross-over from anode to cathode with reduced fuel loss, and stops the HO• and HO2• radicals, originally formed at the anode, entering into PEM matrix. Evidently, the thin PE surface layer provides a highly desirable protecting layer for PEMs to reduce fuel loss and increase chemical stability. Overall, the newly developed PE-g-s-PAES membranes offer a desirable set of PEM properties, including conductivity, selectivity, mechanical strength, stability, and cost-effectiveness for direct methanol fuel cell applications. PMID:26690232

  8. Fuel cell arrangement

    DOEpatents

    Isenberg, A.O.

    1987-05-12

    A fuel cell arrangement is provided wherein cylindrical cells of the solid oxide electrolyte type are arranged in planar arrays where the cells within a plane are parallel. Planes of cells are stacked with cells of adjacent planes perpendicular to one another. Air is provided to the interior of the cells through feed tubes which pass through a preheat chamber. Fuel is provided to the fuel cells through a channel in the center of the cell stack; the fuel then passes the exterior of the cells and combines with the oxygen-depleted air in the preheat chamber. 3 figs.

  9. Fuel cell arrangement

    DOEpatents

    Isenberg, Arnold O.

    1987-05-12

    A fuel cell arrangement is provided wherein cylindrical cells of the solid oxide electrolyte type are arranged in planar arrays where the cells within a plane are parallel. Planes of cells are stacked with cells of adjacent planes perpendicular to one another. Air is provided to the interior of the cells through feed tubes which pass through a preheat chamber. Fuel is provided to the fuel cells through a channel in the center of the cell stack; the fuel then passes the exterior of the cells and combines with the oxygen-depleted air in the preheat chamber.

  10. Micro fuel cell

    SciTech Connect

    Zook, L.A.; Vanderborgh, N.E.; Hockaday, R.

    1998-12-31

    An ambient temperature, liquid feed, direct methanol fuel cell device is under development. A metal barrier layer was used to block methanol crossover from the anode to the cathode side while still allowing for the transport of protons from the anode to the cathode. A direct methanol fuel cell (DMFC) is an electrochemical engine that converts chemical energy into clean electrical power by the direct oxidation of methanol at the fuel cell anode. This direct use of a liquid fuel eliminates the need for a reformer to convert the fuel to hydrogen before it is fed into the fuel cell.

  11. Limitations of Commercializing Fuel Cell Technologies

    NASA Astrophysics Data System (ADS)

    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.

  12. Electrocatalysis of formic acid on palladium and platinum surfaces: from fundamental mechanisms to fuel cell applications.

    PubMed

    Jiang, Kun; Zhang, Han-Xuan; Zou, Shouzhong; Cai, Wen-Bin

    2014-10-14

    Formic acid as a natural biomass and a CO2 reduction product has attracted considerable interest in renewable energy exploitation, serving as both a promising candidate for chemical hydrogen storage material and a direct fuel for low temperature liquid fed fuel cells. In addition to its chemical dehydrogenation, formic acid oxidation (FAO) is a model reaction in the study of electrocatalysis of C1 molecules and the anode reaction in direct formic acid fuel cells (DFAFCs). Thanks to a deeper mechanistic understanding of FAO on Pt and Pd surfaces brought about by recent advances in the fundamental investigations, the "synthesis-by-design" concept has become a mainstream idea to attain high-performance Pt- and Pd-based nanocatalysts. As a result, a large number of efficient nanocatalysts have been obtained through different synthesis strategies by tailoring geometric and electronic structures of the two primary catalytic metals. In this paper, we provide a brief overview of recent progress in the mechanistic studies of FAO, the synthesis of novel Pd- and Pt-based nanocatalysts as well as their practical applications in DFAFCs with a focus on discussing studies significantly contributing to these areas in the past five years.

  13. Electrocatalysis of formic acid on palladium and platinum surfaces: from fundamental mechanisms to fuel cell applications.

    PubMed

    Jiang, Kun; Zhang, Han-Xuan; Zou, Shouzhong; Cai, Wen-Bin

    2014-10-14

    Formic acid as a natural biomass and a CO2 reduction product has attracted considerable interest in renewable energy exploitation, serving as both a promising candidate for chemical hydrogen storage material and a direct fuel for low temperature liquid fed fuel cells. In addition to its chemical dehydrogenation, formic acid oxidation (FAO) is a model reaction in the study of electrocatalysis of C1 molecules and the anode reaction in direct formic acid fuel cells (DFAFCs). Thanks to a deeper mechanistic understanding of FAO on Pt and Pd surfaces brought about by recent advances in the fundamental investigations, the "synthesis-by-design" concept has become a mainstream idea to attain high-performance Pt- and Pd-based nanocatalysts. As a result, a large number of efficient nanocatalysts have been obtained through different synthesis strategies by tailoring geometric and electronic structures of the two primary catalytic metals. In this paper, we provide a brief overview of recent progress in the mechanistic studies of FAO, the synthesis of novel Pd- and Pt-based nanocatalysts as well as their practical applications in DFAFCs with a focus on discussing studies significantly contributing to these areas in the past five years. PMID:25144896

  14. Novel catalysts for hydrogen fuel cell applications:Final report (FY03-FY05).

    SciTech Connect

    Thornberg, Steven Michael; Coker, Eric Nicholas; Jarek, Russell L.; Steen, William Arthur

    2005-12-01

    The goal of this project was to develop novel hydrogen-oxidation electrocatalyst materials that contain reduced platinum content compared to traditional catalysts by developing flexible synthesis techniques to fabricate supported catalyst structures, and by verifying electrochemical performance in half cells and ultimately laboratory fuel cells. Synthesis methods were developed for making small, well-defined platinum clusters using zeolite hosts, ion exchange, and controlled calcination/reduction processes. Several factors influence cluster size, and clusters below 1 nm with narrow size distribution have been prepared. To enable electrochemical application, the zeolite pores were filled with electrically-conductive carbon via infiltration with carbon precursors, polymerization/cross-linking, and pyrolysis under inert conditions. The zeolite host was then removed by acid washing, to leave a Pt/C electrocatalyst possessing quasi-zeolitic porosity and Pt clusters of well-controlled size. Plotting electrochemical activity versus pyrolysis temperature typically produces a Gaussian curve, with a peak at ca. 800 C. The poorer relative performances at low and high temperature are due to low electrical conductivity of the carbon matrix, and loss of zeolitic structure combined with Pt sintering, respectively. Cluster sizes measured via adsorption-based methods were consistently larger than those observed by TEM and EXAFS, suggesting , that a fraction of the clusters were inaccessible to the fluid phase. Detailed EXAFS analysis has been performed on selected catalysts and catalyst precursors to monitor trends in cluster size evolution, as well as oxidation states of Pt. Experiments were conducted to probe the electroactive surface area of the Pt clusters. These Pt/C materials had as much as 110 m{sup 2}/g{sub pt} electroactive surface area, an almost 30% improvement over what is commercially (mfg. by ETEK) available (86 m{sup 2}/g{sub pt}). These Pt/C materials also perform

  15. Direct hydrocarbon fuel cells

    DOEpatents

    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.

  16. Analysis and control of an in situ hydrogen generation and fuel cell power system for automotive applications

    NASA Astrophysics Data System (ADS)

    Kolavennu, Panini K.

    A new future in automotive transportation is approaching where vehicles are powered by new, clean and efficient energy sources. While different technologies will contribute to this future, many see fuel cells as the leading long term candidate for becoming the power source for emissions-free, mass produced light vehicles. The development of emissions-free vehicles, which run directly on hydrogen, is the true long term goal. However significant difficulties exist in developing these vehicles, due to hydrogen storage problems. For automotive applications, it is desirable to use a carbon-based hydrogenous fuel. The focus of this research was to analyze a fuel cell system for automotive applications, which generated hydrogen in situ using methane as a fuel source. This system consists of four parts: (1) an in situ hydrogen generation subsystem, (2) a power generation subsystem, (3) a thermal management subsystem and (4) a switching control subsystem. The novelty of this research lies in the fact that the entire system was considered from a systems engineering viewpoint with realistic constraints. A fuel processor subsystem was designed and its volume optimized to less than 100 liters. A relationship between the fuel fed into the fuel processor and the hydrogen coming out of it was developed. Using a fuel cell model an overall relationship between the fuel feed rate and the power output was established. The fuel cell car must be fully operational within a minute or so of a cold-start and must respond to rapidly varying loads. Significant load transitions occur frequently as a result of changes in driving conditions. These engineering constraints were addressed by coupling a battery to the fuel cell. A switching controller was designed and it was validated using realistic power profiles. Finally, a model reference adaptive controller was designed to handle nonlinearities and load transitions. The adaptive controller performance was enhanced by adding dead zone

  17. Fuel cells and fuel cell catalysts

    DOEpatents

    Masel, Richard I.; Rice, Cynthia A.; Waszczuk, Piotr; Wieckowski, Andrzej

    2006-11-07

    A direct organic fuel cell includes a formic acid fuel solution having between about 10% and about 95% formic acid. The formic acid is oxidized at an anode. The anode may include a Pt/Pd catalyst that promotes the direct oxidation of the formic acid via a direct reaction path that does not include formation of a CO intermediate.

  18. Advanced NaBH4/H2O2 Fuel Cell for Space Applications

    NASA Astrophysics Data System (ADS)

    Miley, George H.; Kim, Kyu-Jung; Luo, Nie; Shrestha, Prajakti Joshi

    2009-03-01

    Fuel cells have played an important role in NASA's space program starting with the Gemini space program. However, improved fuel cell performance will be needed to enable demanding future missions. An advanced fuel cell (FC) using liquid fuel and oxidizer is being developed by U of IL/NPL team to provide air independence and to achieve higher power densities than normal H2/O2 fuel cells (Lou et al., 2008; Miley, 2007). Hydrogen peroxide (H2O2) is used in this FC directly at the cathode (Lou and Miley, 2004). Either of two types of reactant, namely a gas-phase hydrogen or an aqueous NaBH4 solution, is utilized as fuel at the anode. Experiments with both 10-W single cells and 500-W stacks demonstrate that the direct utilization of H2O2 and NaBH4 at the electrodes result in >30% higher voltage output compared to the ordinary H2/O2 FC (Miley, 2007). Further, the use of this combination of all liquid fuels provides—from an operational point of view—significant advantages (ease of storage, reduced pumping requirements, simplified heat removal). This design is inherently compact compared to other fuel cells that use gas phase reactants. This results in a high overall system (including fuel tanks, pumps and piping, waste heat radiator) power density. Further, work is in progress on a regenerative version which uses an electrical input, e.g. from power lines or a solar panel to regenerate reactants.

  19. Operational Concept Evaluation of Solid Oxide Fuel Cells for Space Vehicle Applications

    NASA Technical Reports Server (NTRS)

    Poast, Kenneth I.

    2011-01-01

    With the end of the Space Shuttle Program, NASA is evaluating many different technologies to support future missions. Green propellants, like liquid methane and liquid oxygen, have potential advantages for some applications. A Lander propelled with LOX/methane engines is one such application. When the total vehicle design and infrastructure are considered, the advantages of the integration of propulsion, heat rejection, life support and power generation become attractive for further evaluation. Scavenged residual propellants from the propulsion tanks could be used to generate needed electric power, heat and water with a Solid Oxide Fuel Cell(SOFC). In-Situ Resource Utilization(ISRU) technologies may also generate quantities of green propellants to refill these tanks and/or supply these fuel cells. Technology demonstration projects such as the Morpheus Lander are currently underway to evaluate the practicality of such designs and operational concepts. Tethered tests are currently in progress on this vertical test bed to evaluate the propulsion and avionics systems. Evaluation of the SOFC seeks to determine the feasibility of using these green propellants to supply power and identify the limits to the integration of this technology into a space vehicle prototype.

  20. NASA's PEM Fuel Cell Power Plant Development Program for Space Applications

    NASA Technical Reports Server (NTRS)

    Hoberecht, Mark

    2006-01-01

    NASA embarked on a PEM fuel cell power plant development program beginning in 2001. This five-year program was conducted by a three-center NASA team of Glenn Research Center (lead), Johnson Space Center, and Kennedy Space Center. The program initially was aimed at developing hardware for a Reusable Launch Vehicle (RLV) application, but more recently had shifted to applications supporting the NASA Exploration Program. The first phase of the development effort, to develop breadboard hardware in the 1-5 kW power range, was conducted by two competing vendors. The second phase of the effort, to develop Engineering Model hardware at the 10 kW power level, was conducted by the winning vendor from the first phase of the effort. Both breadboard units and the single engineering model power plant were delivered to NASA for independent testing. This poster presentation will present a summary of both phases of the development effort, along with a discussion of test results of the PEM fuel cell engineering model under simulated mission conditions.

  1. Directly applicable microbial fuel cells in aeration tank for wastewater treatment.

    PubMed

    Cha, Jaehwan; Choi, Soojung; Yu, Hana; Kim, Hyosoo; Kim, Changwon

    2010-04-01

    The application of microbial fuel cell (MFC) for wastewater treatment is a promising strategy for the simultaneous treatment of pollutants and generation of electricity. However, for practical application, there are several limitations to the MFC that involve biological and engineering aspects. In this study, a single-chambered MFC able to submerge into the aeration tank of the activated sludge process was developed to optimize the cell configuration and electrode materials. Among four MFCs with different electrode materials, the MFC with a graphite felt (GF) anode and a GF cathode showed the highest power density of 16.7 W m(-3) and the lowest internal resistance of 17 Omega. When the blower was stopped to evaluate the effect of mixing intensity, the concentration of dissolved oxygen nevertheless remained at 8 mg O2 L(-1), and the cell voltage of MFCs dropped rapidly and reached 30 mV. However, the cell voltage immediately returned to around 200 mV after the blowing of air. The MFCs with a GF cathode were sensitive to mixing intensity. At the very low concentration of 0.2 mg O2 L(-1), the cell voltage remained at a high level of 200 mV when the oxygen close to the cathode remained and mixing was sufficient.

  2. Added value for on-site fuel cells through equipment and application integration

    SciTech Connect

    Whitaker, R.

    1996-12-31

    On-site fuel cell power plants are not an exciting new electricity generating technology. They are an economic and beneficial addition to the operating systems of commercial buildings and industrial facilities. ONSI Corporation is part of International Fuel Cells Corporation and is jointly owned by United Technologies Corporation, Toshiba, and Ansaldo. ONSI has proven in the last three years that initial demand for packaged fuel cell power plants, like our 200 kW PC25{trademark} fuel cell shown in Figure 1, comes from the commercial building sector. However, this sector and the companies which service it are only tangentially interested in fuel cells as an emerging electricity generating technology. What they are most interested in is how the PC25 can integrate into their building`s system; how it can deliver energy efficient dollars to the bottom line, and how it can deliver operating benefits to their business.

  3. The Development of Fuel Cell Technology for Electric Power Generation - From Spacecraft Applications to the Hydrogen Economy

    NASA Technical Reports Server (NTRS)

    Scott, John H.

    2005-01-01

    The fuel cell uses a catalyzed reaction between a fuel and an oxidizer to directly produce electricity. Its high theoretical efficiency and low temperature operation made it a subject of much study upon its invention ca. 1900, but its relatively high life cycle costs kept it as "solution in search of a problem" for its first half century. The first problem for which fuel cells presented a cost effective solution was, starting in the 1960's that of a power source for NASA's manned spacecraft. NASA thus invested, and continues to invest, in the development of fuel cell power plants for this application. However, starting in the mid-1990's, prospective environmental regulations have driven increased governmental and industrial interest in "green power" and the "Hydrogen Economy." This has in turn stimulated greatly increased investment in fuel cell development for a variety of terrestrial applications. This investment is bringing about notable advances in fuel cell technology, but these advances are often in directions quite different from those needed for NASA spacecraft applications. This environment thus presents both opportunities and challenges for NASA's manned space program.

  4. Fuel cell generator

    DOEpatents

    Isenberg, Arnold O.

    1983-01-01

    High temperature solid oxide electrolyte fuel cell generators which allow controlled leakage among plural chambers in a sealed housing. Depleted oxidant and fuel are directly reacted in one chamber to combust remaining fuel and preheat incoming reactants. The cells are preferably electrically arranged in a series-parallel configuration.

  5. Continuous Preparation of Carbon Nanotube Film and Its Applications in Fuel and Solar Cells.

    PubMed

    Luo, Xiao Gang; Huang, Xin Xin; Wang, Xiao Xia; Zhong, Xin Hua; Meng, Xin Xin; Wang, Jian Nong

    2016-03-01

    So far, simultaneously realizing the continuous, controllable, and scalable preparation of carbon nanotube (CNT) film has remained a big challenge. Here, we report a scalable approach to continuously prepare CNT film with good control of film size and thickness. This is achieved through the layer-by-layer condensation and deposition of a cylindrical CNT assembly that is continuously produced from a floating catalyst CVD reactor on a paper strip. The promising applications of such a film are demonstrated by directly using it as an effective protecting layer for the Pt/C catalyst in proton exchange membrane fuel cells and as an efficient counter electrode material in quantum-dot-sensitized solar cells.

  6. Reforming of fuel inside fuel cell generator

    DOEpatents

    Grimble, Ralph E.

    1988-01-01

    Disclosed is an improved method of reforming a gaseous reformable fuel within a solid oxide fuel cell generator, wherein the solid oxide fuel cell generator has a plurality of individual fuel cells in a refractory container, the fuel cells generating a partially spent fuel stream and a partially spent oxidant stream. The partially spent fuel stream is divided into two streams, spent fuel stream I and spent fuel stream II. Spent fuel stream I is burned with the partially spent oxidant stream inside the refractory container to produce an exhaust stream. The exhaust stream is divided into two streams, exhaust stream I and exhaust stream II, and exhaust stream I is vented. Exhaust stream II is mixed with spent fuel stream II to form a recycle stream. The recycle stream is mixed with the gaseous reformable fuel within the refractory container to form a fuel stream which is supplied to the fuel cells. Also disclosed is an improved apparatus which permits the reforming of a reformable gaseous fuel within such a solid oxide fuel cell generator. The apparatus comprises a mixing chamber within the refractory container, means for diverting a portion of the partially spent fuel stream to the mixing chamber, means for diverting a portion of exhaust gas to the mixing chamber where it is mixed with the portion of the partially spent fuel stream to form a recycle stream, means for injecting the reformable gaseous fuel into the recycle stream, and means for circulating the recycle stream back to the fuel cells.

  7. Reforming of fuel inside fuel cell generator

    DOEpatents

    Grimble, R.E.

    1988-03-08

    Disclosed is an improved method of reforming a gaseous reformable fuel within a solid oxide fuel cell generator, wherein the solid oxide fuel cell generator has a plurality of individual fuel cells in a refractory container, the fuel cells generating a partially spent fuel stream and a partially spent oxidant stream. The partially spent fuel stream is divided into two streams, spent fuel stream 1 and spent fuel stream 2. Spent fuel stream 1 is burned with the partially spent oxidant stream inside the refractory container to produce an exhaust stream. The exhaust stream is divided into two streams, exhaust stream 1 and exhaust stream 2, and exhaust stream 1 is vented. Exhaust stream 2 is mixed with spent fuel stream 2 to form a recycle stream. The recycle stream is mixed with the gaseous reformable fuel within the refractory container to form a fuel stream which is supplied to the fuel cells. Also disclosed is an improved apparatus which permits the reforming of a reformable gaseous fuel within such a solid oxide fuel cell generator. The apparatus comprises a mixing chamber within the refractory container, means for diverting a portion of the partially spent fuel stream to the mixing chamber, means for diverting a portion of exhaust gas to the mixing chamber where it is mixed with the portion of the partially spent fuel stream to form a recycle stream, means for injecting the reformable gaseous fuel into the recycle stream, and means for circulating the recycle stream back to the fuel cells. 1 fig.

  8. Thermodynamic analysis of Direct Urea Solid Oxide Fuel Cell in combined heat and power applications

    NASA Astrophysics Data System (ADS)

    Abraham, F.; Dincer, I.

    2015-12-01

    This paper presents a comprehensive steady state modelling and thermodynamic analysis of Direct Urea Solid Oxide Fuel Cell integrated with Gas Turbine power cycle (DU-SOFC/GT). The use of urea as direct fuel mitigates public health and safety risks associated with the use of hydrogen and ammonia. The integration scheme in this study covers both oxygen ion-conducting solid oxide fuel cells (SOFC-O) and hydrogen proton-conducting solid oxide fuel cells (SOFC-H). Parametric case studies are carried out to investigate the effects of design and operating parameters on the overall performance of the system. The results reveal that the fuel cell exhibited the highest level of exergy destruction among other system components. Furthermore, the SOFC-O based system offers better overall performance than that with the SOFC-H option mainly due to the detrimental reverse water-gas shift reaction at the SOFC anode as well as the unique configuration of the system.

  9. U.S. DOE Progress Towards Developing Low-Cost, High Performance, Durable Polymer Electrolyte Membranes for Fuel Cell Applications.

    PubMed

    Houchins, Cassidy; Kleen, Greg J; Spendelow, Jacob S; Kopasz, John; Peterson, David; Garland, Nancy L; Ho, Donna Lee; Marcinkoski, Jason; Martin, Kathi Epping; Tyler, Reginald; Papageorgopoulos, Dimitrios C

    2012-12-18

    Low cost, durable, and selective membranes with high ionic conductivity are a priority need for wide-spread adoption of polymer electrolyte membrane fuel cells (PEMFCs) and direct methanol fuel cells (DMFCs). Electrolyte membranes are a major cost component of PEMFC stacks at low production volumes. PEMFC membranes also impose limitations on fuel cell system operating conditions that add system complexity and cost. Reactant gas and fuel permeation through the membrane leads to decreased fuel cell performance, loss of efficiency, and reduced durability in both PEMFCs and DMFCs. To address these challenges, the U.S. Department of Energy (DOE) Fuel Cell Technologies Program, in the Office of Energy Efficiency and Renewable Energy, supports research and development aimed at improving ion exchange membranes for fuel cells. For PEMFCs, efforts are primarily focused on developing materials for higher temperature operation (up to 120 °C) in automotive applications. For DMFCs, efforts are focused on developing membranes with reduced methanol permeability. In this paper, the recently revised DOE membrane targets, strategies, and highlights of DOE-funded projects to develop new, inexpensive membranes that have good performance in hot and dry conditions (PEMFC) and that reduce methanol crossover (DMFC) will be discussed.

  10. U.S. DOE Progress Towards Developing Low-Cost, High Performance, Durable Polymer Electrolyte Membranes for Fuel Cell Applications

    PubMed Central

    Houchins, Cassidy; Kleen, Greg J.; Spendelow, Jacob S.; Kopasz, John; Peterson, David; Garland, Nancy L.; Ho, Donna Lee; Marcinkoski, Jason; Martin, Kathi Epping; Tyler, Reginald; Papageorgopoulos, Dimitrios C.

    2012-01-01

    Low cost, durable, and selective membranes with high ionic conductivity are a priority need for wide-spread adoption of polymer electrolyte membrane fuel cells (PEMFCs) and direct methanol fuel cells (DMFCs). Electrolyte membranes are a major cost component of PEMFC stacks at low production volumes. PEMFC membranes also impose limitations on fuel cell system operating conditions that add system complexity and cost. Reactant gas and fuel permeation through the membrane leads to decreased fuel cell performance, loss of efficiency, and reduced durability in both PEMFCs and DMFCs. To address these challenges, the U.S. Department of Energy (DOE) Fuel Cell Technologies Program, in the Office of Energy Efficiency and Renewable Energy, supports research and development aimed at improving ion exchange membranes for fuel cells. For PEMFCs, efforts are primarily focused on developing materials for higher temperature operation (up to 120 °C) in automotive applications. For DMFCs, efforts are focused on developing membranes with reduced methanol permeability. In this paper, the recently revised DOE membrane targets, strategies, and highlights of DOE-funded projects to develop new, inexpensive membranes that have good performance in hot and dry conditions (PEMFC) and that reduce methanol crossover (DMFC) will be discussed. PMID:24958432

  11. Commercializing fuel cells: managing risks

    NASA Astrophysics Data System (ADS)

    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

  12. Evaluation of a Passive Heat Exchanger Based Cooling System for Fuel Cell Applications

    NASA Technical Reports Server (NTRS)

    Colozza, Anthony J.; Burke, Kenneth A.

    2011-01-01

    Fuel cell cooling is conventionally performed with an actively controlled, dedicated coolant loop that exchanges heat with a separate external cooling loop. To simplify this system the concept of directly cooling a fuel cell utilizing a coolant loop with a regenerative heat exchanger to preheat the coolant entering the fuel cell with the coolant exiting the fuel cell was analyzed. The preheating is necessary to minimize the temperature difference across the fuel cell stack. This type of coolant system would minimize the controls needed on the coolant loop and provide a mostly passive means of cooling the fuel cell. The results indicate that an operating temperature of near or greater than 70 C is achievable with a heat exchanger effectiveness of around 90 percent. Of the heat exchanger types evaluated with the same type of fluid on the hot and cold side, a counter flow type heat exchanger would be required which has the possibility of achieving the required effectiveness. The number of heat transfer units required by the heat exchanger would be around 9 or greater. Although the analysis indicates the concept is feasible, the heat exchanger design would need to be developed and optimized for a specific fuel cell operation in order to achieve the high effectiveness value required.

  13. The NASA LeRC regenerative fuel cell system testbed program for goverment and commercial applications

    SciTech Connect

    Maloney, T.M.; Voecks, G.E.

    1995-01-25

    The Electrochemical Technology Branch of the NASA Lewis Research Center (LeRC) has initiated a program to develop a renewable energy system testbed to evaluate, characterize, and demonstrate fully integrated regenerative fuel cell (RFC) system for space, military, and commercial applications. A multi-agency management team, led by NASA LeRC, is implementing the program through a unique international coalition which encompasses both government and industry participants. This open-ended teaming strategy optimizes the development for space, military, and commercial RFC system technologies. Program activities to date include system design and analysis, and reactant storage sub-system design, with a major emphasis centered upon testbed fabrication and installation and testing of two key RFC system components, namely, the fuel cells and electrolyzers. Construction of the LeRC 25 kW RFC system testbed at the NASA-Jet Propulsion Labortory (JPL) facility at Edwards Air Force Base (EAFB) is nearly complete and some sub-system components have already been installed. Furthermore, planning for the first commercial RFC system demonstration is underway. {copyright} {ital 1995} {ital American} {ital Institute} {ital of} {ital Physics}

  14. The NASA LeRC regenerative fuel cell system testbed program for goverment and commercial applications

    NASA Astrophysics Data System (ADS)

    Maloney, Thomas M.; Prokopius, Paul R.; Voecks, Gerald E.

    1995-01-01

    The Electrochemical Technology Branch of the NASA Lewis Research Center (LeRC) has initiated a program to develop a renewable energy system testbed to evaluate, characterize, and demonstrate fully integrated regenerative fuel cell (RFC) system for space, military, and commercial applications. A multi-agency management team, led by NASA LeRC, is implementing the program through a unique international coalition which encompasses both government and industry participants. This open-ended teaming strategy optimizes the development for space, military, and commercial RFC system technologies. Program activities to date include system design and analysis, and reactant storage sub-system design, with a major emphasis centered upon testbed fabrication and installation and testing of two key RFC system components, namely, the fuel cells and electrolyzers. Construction of the LeRC 25 kW RFC system testbed at the NASA-Jet Propulsion Labortory (JPL) facility at Edwards Air Force Base (EAFB) is nearly complete and some sub-system components have already been installed. Furthermore, planning for the first commercial RFC system demonstration is underway.

  15. Making the grid the backup: Utility applications for fuel cell power

    SciTech Connect

    Eklof, S.L.

    1996-12-31

    Fuel cells are recognized as a versatile power generation option and accepted component of SMUD`s ART Program. SMUD has received wide support and recognition for promoting and implementing fuel cell power plants, as well as other innovative generation, based primarily on technological factors. Current economic and technical realities in the electric generation market highlight other important factors, such as the cost involved to develop a slate of such resources. The goal now is to develop only those select quality resources most likely to become commercially viable in the near future. The challenge becomes the identification of candidate technologies with the greatest potential, and then matching the technologies with the applications that will help to make them successful. Utility participation in this development is critical so as to provide the industry with case examples of advanced technologies that can be applied in a way beneficial to both the utility and its customers. The ART resource acquisitions provide the experience base upon which to guide this selection process, and should bring about the cost reductions and reliability improvements sought.

  16. Applications of profile filtering in the dimensional metrology of fuel cell plates

    NASA Astrophysics Data System (ADS)

    Muralikrishnan, Bala; Ren, Wei; Stanfield, Eric; Everett, Dennis; Zheng, Alan; Doiron, Ted

    2013-06-01

    We describe the application of several surface profile filters as an enabling tool in the dimensional measurements of an engineering artifact, namely, a fuel cell plate. We recently reported work on the development of a non-contact system for dimensional metrology of bipolar fuel cell plates. That system comprises two laser spot triangulation probes that acquire profile data across a plate. While the non-contact system provides rapid measurements (measurement speed of 100 mm s-1 to 500 mm s-1), the data are noisy and cannot be used directly to obtain features of interest such as channel depth and width. In this paper, we show how different surface profile filters such as the spline, morphological, and robust filters, can be employed to identify and suppress outliers and to produce a mean line that serves as a substitute geometry from which we can determine features of interest. Further, we compare the non-contact probe data against contact probe measurements made using a coordinate measuring machine. Surface profile filters are again useful in correcting the reference data for tip size and also in removing any free form deformation in both data sets prior to parameter evaluation and comparison.

  17. Fuel cell development for transportation: Catalyst development

    SciTech Connect

    Doddapaneni, N.

    1996-04-01

    Fuel cells are being considered as alternate power sources for transportation and stationary applications. With proton exchange membrane (PEM) fuel cells the fuel crossover to cathodes causes severe thermal management and cell voltage drop due to oxidation of fuel at the platinized cathodes. The main goal of this project was to design, synthesize, and evaluate stable and inexpensive transition metal macrocyclic catalysts for the reduction of oxygen and be electrochemically inert towards anode fuels such as hydrogen and methanol.

  18. Navy fuel cell demonstration project.

    SciTech Connect

    Black, Billy D.; Akhil, Abbas Ali

    2008-08-01

    This is the final report on a field evaluation by the Department of the Navy of twenty 5-kW PEM fuel cells carried out during 2004 and 2005 at five Navy sites located in New York, California, and Hawaii. The key objective of the effort was to obtain an engineering assessment of their military applications. Particular issues of interest were fuel cell cost, performance, reliability, and the readiness of commercial fuel cells for use as a standalone (grid-independent) power option. Two corollary objectives of the demonstration were to promote technological advances and to improve fuel performance and reliability. From a cost perspective, the capital cost of PEM fuel cells at this stage of their development is high compared to other power generation technologies. Sandia National Laboratories technical recommendation to the Navy is to remain involved in evaluating successive generations of this technology, particularly in locations with greater environmental extremes, and it encourages their increased use by the Navy.

  19. Molten carbonate fuel cell

    DOEpatents

    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.

  20. Molten carbonate fuel cell

    DOEpatents

    Kaun, Thomas D.; Smith, James L.

    1987-01-01

    A molten electrolyte fuel cell 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 providing an enclosure for the array and effectively avoiding the problems of electrolyte migration and the previous need for compression of stack components, the fuel cell further including 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.

  1. Development of a Solid-Oxide Fuel Cell/Gas Turbine Hybrid System Model for Aerospace Applications

    NASA Technical Reports Server (NTRS)

    Freeh, Joshua E.; Pratt, Joseph W.; Brouwer, Jacob

    2004-01-01

    Recent interest in fuel cell-gas turbine hybrid applications for the aerospace industry has led to the need for accurate computer simulation models to aid in system design and performance evaluation. To meet this requirement, solid oxide fuel cell (SOFC) and fuel processor models have been developed and incorporated into the Numerical Propulsion Systems Simulation (NPSS) software package. The SOFC and reformer models solve systems of equations governing steady-state performance using common theoretical and semi-empirical terms. An example hybrid configuration is presented that demonstrates the new capability as well as the interaction with pre-existing gas turbine and heat exchanger models. Finally, a comparison of calculated SOFC performance with experimental data is presented to demonstrate model validity. Keywords: Solid Oxide Fuel Cell, Reformer, System Model, Aerospace, Hybrid System, NPSS

  2. Automotive Fuel Processor Development and Demonstration with Fuel Cell Systems

    SciTech Connect

    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 processor

  3. Application of ionic and electronic conducting ceramics in solid oxide fuel cells

    SciTech Connect

    Singhal, S.C.

    1997-12-01

    Solid oxide fuel cells (SOFCs) offer a pollution-free technology to electrochemically generate electricity at high efficiencies. These fuel cells consist of an oxygen ion conducting electrolyte, electronic or mixed electronic and ionic conducting electrodes, and an electronic conducting interconnection. This paper reviews the ceramic materials used for the different cell components, and discusses the performance of cells fabricated using these materials. The paper also discusses the materials and processing studies that are underway to reduce the cell cost, and summarizes the recently built power generation systems that employed state-of-the-art SOFCs.

  4. Symposium on Batteries and Fuel Cells for Stationary and Electric Vehicle Applications, Honolulu, HI, May 16-21, 1993, Proceedings

    NASA Astrophysics Data System (ADS)

    Landgrebe, Albert R.; Takehara, Zen-Ichiro

    The present conference discusses the development status of vehicular batteries in Japan, the effects of the solvent for electropolymerization of aniline on the charge/discharge characteristics of polyaniline, the charge/discharge mechanism of the amorphous FeOOH, including aniline as a cathode for a rechargeable Li battery, the effect of mesocarbon microbead structure on the electrochemistry of Li secondary batteries' negative electrode, and novel aluminum batteries. Also discussed are a room-temperature molten salt electrolyte for the Na/iron chloride battery, portable cells for redox batteries, the development status of lead-acid batteries for electric vehicles, mechanically refuelable zinc/air vehicular cells, polymer electrolyte fuel cells for transportation applications, proton exchange membrane fuel cells using gas-fed methanol, and a phosphotic acid fuel cell/battery.

  5. Fuel cells with solid polymer electrolyte and their application on vehicles

    SciTech Connect

    Fateev, V.

    1996-04-01

    In Russia, solid polymer electrolyte MF-4-SK has been developed for fuel cells. This electrolyte is based on perfluorinated polymer with functional sulfogroups. Investigations on electrolyte properties and electrocatalysts have been carried out.

  6. Development of a 10 kW PEM fuel cell for stationary applications

    SciTech Connect

    Barthels, H.; Mergel, J.; Oetjen, H.F.

    1996-12-31

    A 10 kW Proton Exchange Membrane Fuel Cell (PEMFC) is being developed as part of a long-term energy storage path for electricity in the photovoltaic demonstration plant called PHOEBUS at the Forschungszentrum Julich.

  7. Development of a Hybrid Compressor/Expander Module for Automotive Fuel Cell Applications

    SciTech Connect

    McTaggart, Paul

    2004-12-31

    In this program TIAX LLC conducted the development of an advanced technology compressor/expander for supplying compressed air to Proton Exchange Membrane (PEM) fuel cells in transportation applications. The overall objective of this program was to develop a hybrid compressor/expander module, based on both scroll and high-speed turbomachinery technologies, which will combine the strengths of each technology to create a concept with superior performance at minimal size and cost. The resulting system was expected to have efficiency and pressure delivery capability comparable to that of a scroll-only machine, at significantly reduced system size and weight when compared to scroll-only designs. Based on the results of detailed designs and analyses of the critical system elements, the Hybrid Compressor/Expander Module concept was projected to deliver significant improvements in weight, volume and manufacturing cost relative to previous generation systems.

  8. Polysulfone functionalized with phosphonated poly(pentafluorostyrene) grafts for potential fuel cell applications.

    PubMed

    Dimitrov, Ivaylo; Takamuku, Shogo; Jankova, Katja; Jannasch, Patric; Hvilsted, Søren

    2012-08-28

    A multi-step synthetic strategy to polysulfone (PSU) grafted with phosphonated poly(pentafluorostyrene) (PFS) is developed. It involves controlled radical polymerization resulting in alkyne-end functional PFS. The next step is the modification of PSU with a number of azide side groups. The grafting of PFS onto PSU backbone is performed via the "click"-chemistry approach. In a final step, the PFS-grafts are subjected to the post phosphonation. The copolymers are evaluated as membranes for potential fuel cell applications through thermal analyses, water uptake, and conductivity measurements. The proposed synthetic route opens the possibility to tune copolymers' hydrophilic-hydrophobic balance to obtain membranes with an optimal balance between proton conductivity and mechanical properties.

  9. Polysulfone functionalized with phosphonated poly(pentafluorostyrene) grafts for potential fuel cell applications.

    PubMed

    Dimitrov, Ivaylo; Takamuku, Shogo; Jankova, Katja; Jannasch, Patric; Hvilsted, Søren

    2012-08-28

    A multi-step synthetic strategy to polysulfone (PSU) grafted with phosphonated poly(pentafluorostyrene) (PFS) is developed. It involves controlled radical polymerization resulting in alkyne-end functional PFS. The next step is the modification of PSU with a number of azide side groups. The grafting of PFS onto PSU backbone is performed via the "click"-chemistry approach. In a final step, the PFS-grafts are subjected to the post phosphonation. The copolymers are evaluated as membranes for potential fuel cell applications through thermal analyses, water uptake, and conductivity measurements. The proposed synthetic route opens the possibility to tune copolymers' hydrophilic-hydrophobic balance to obtain membranes with an optimal balance between proton conductivity and mechanical properties. PMID:22623205

  10. SHAPE SELECTIVE NANO-CATALYSTS: TOWARD DIRECT METHANOL FUEL CELLS APPLICATIONS

    SciTech Connect

    Murph, S.

    2010-06-16

    A series of bimetallic core-shell-alloy type Au-Pt nanomaterials with various morphologies, aspect ratios and compositions, were produced in a heterogenous epitaxial fashion. Gold nanoparticles with well-controlled particle size and shape, e.g. spheres, rods and cubes, were used as 'seeds' for platinum growth in the presence of a mild reducing agent, ascorbic acid and a cationic surfactant cethyltrimethyl ammonium bromide (CTAB). The reactions take place in air and water, and are quick, economical and amenable for scaling up. The synthesized nanocatalysts were characterized by electron microscopy techniques and energy dispersive X-ray analysis. Nafion membranes were embedded with the Au-Pt nanomaterials and analyzed by atomic force microscopy (AFM) and scanning electron microscopy (SEM) for their potential in direct methanol fuel cells applications.

  11. Application of a weak magnetic field to improve microbial fuel cell performance.

    PubMed

    Tong, Zhong-Hua; Yu, Han-Qing; Li, Wen-Wei; Wang, Yun-Kun; Sun, Min; Liu, Xian-Wei; Sheng, Guo-Ping

    2015-12-01

    Microbial fuel cells (MFCs) have emerged as a promising technology for wastewater treatment with concomitant energy production but the performance is usually limited by low microbial activities. This has spurred intensive research interest for microbial enhancement. This study demonstrated an interesting stimulation effect of a static magnetic field (MF) on sludge-inoculated MFCs and explored into the mechanisms. The implementation of a 100-mT MF accelerated the reactor startup and led to increased electricity generation. Under the MF exposure, the activation loss of the MFC was decreased, but there was no increased secretion of redox mediators. Thus, the MF effect was mainly due to enhanced bioelectrochemical activities of anodic microorganisms, which are likely attributed to the oxidative stress and magnetohydrodynamic effects under an MF exposure. This work implies that weak MF may be applied as a simple and effective approach to stimulate microbial activities for various bioelectrochemical energy production and decontamination applications.

  12. Direct-hydrogen-fueled proton-exchange-membrane fuel cell system for transportation applications. Hydrogen vehicle safety report

    SciTech Connect

    Thomas, C.E.

    1997-05-01

    This report reviews the safety characteristics of hydrogen as an energy carrier for a fuel cell vehicle (FCV), with emphasis on high pressure gaseous hydrogen onboard storage. The authors consider normal operation of the vehicle in addition to refueling, collisions, operation in tunnels, and storage in garages. They identify the most likely risks and failure modes leading to hazardous conditions, and provide potential countermeasures in the vehicle design to prevent or substantially reduce the consequences of each plausible failure mode. They then compare the risks of hydrogen with those of more common motor vehicle fuels including gasoline, propane, and natural gas.

  13. Pt-Ni and Pt-Co Catalyst Synthesis Route for Fuel Cell Applications

    NASA Technical Reports Server (NTRS)

    Firdosy, Samad A.; Ravi, Vilupanur A.; Valdez, Thomas I.; Kisor, Adam; Narayan, Sri R.

    2013-01-01

    Oxygen reduction reactions (ORRs) at the cathode are the rate-limiting step in fuel cell performance. The ORR is 100 times slower than the corresponding hydrogen oxidation at the anode. Speeding up the reaction at the cathode will improve fuel cell efficiency. The cathode material is generally Pt powder painted onto a substrate (e.g., graphite paper). Recent efforts in the fuel cell area have focused on replacing Pt with Pt-X alloys (where X = Co, Ni, Zr, etc.) in order to (a) reduce cost, and (b) increase ORR rates. One of these strategies is to increase ORR rates by reducing the powder size, which would result in an increase in the surface area, thereby facilitating faster reaction rates. In this work, a process has been developed that creates Pt-Ni or Pt-Co alloys that are finely divided (on the nano scale) and provide equivalent performance at lower Pt loadings. Lower Pt loadings will translate to lower cost. Precursor salts of the metals are dissolved in water and mixed. Next, the salt mixtures are dried on a hot plate. Finally, the dried salt mixture is heattreated in a furnace under flowing reducing gas. The catalyst powder is then used to fabricate a membrane electrode assembly (MEA) for electrochemical performance testing. The Pt- Co catalyst-based MEA showed comparable performance to an MEA fabri cated using a standard Pt black fuel cell catalyst. The main objective of this program has been to increase the overall efficiencies of fuel cell systems to support power for manned lunar bases. This work may also have an impact on terrestrial programs, possibly to support the effort to develop a carbon-free energy source. This catalyst can be used to fabricate high-efficiency fuel cell units that can be used in space as regenerative fuel cell systems, and terrestrially as primary fuel cells. Terrestrially, this technology will become increasingly important when transition to a hydrogen economy occurs.

  14. Application of acetate, lactate, and fumarate as electron donors in microbial fuel cell

    NASA Astrophysics Data System (ADS)

    Vasyliv, Oresta M.; Bilyy, Oleksandr I.; Ferensovych, Yaroslav P.; Hnatush, Svitlana O.

    2013-09-01

    Microbial fuel cells (MFCs) are devices that use bacteria as the catalysts to oxidize organic and inorganic matter and generate current. Up to now, several classes of extracellular electron transfer mechanisms have been elucidated for various microorganisms. Shewanellaceae and Geobacteraceae families include the most of model exoelectrogenic microorganisms. Desulfuromonas acetoxidans bacterium inhabits aquatic sedimental sulfur-containing environments and is philogenetically close to representatives of Geobacteraceae family. Two chamber microbial fuel cell (0.3 l volume) was constructed with application of D. acetoxidans IMV B-7384 as anode biocatalyst. Acetic, lactic and fumaric acids were separately applied as organic electron donors for bacterial growth in constructed MFC. Bacterial cultivation in MFC was held during twenty days. Lactate oxidation caused electric power production with the highest value up to 0.071 mW on 64 hour of D. acetoxidans IMV B-7384 growth. Addition of acetic and fumaric acids into bacterial growth medium caused maximal power production up to 0.075 and 0.074 mW respectively on the 40 hour of their growth. Increasing of incubation time up to twentieth day caused decrease of generated electric power till 0.018 mW, 0.042 mW and 0.047 mW under usage of lactic, acetic and fumaric acids respectively by investigated bacteria. Power generation by D. acetoxidans IMV B-7384 was more stabile and durable under application of acetic and fumaric acids as electron donors in constructed MFC, than under addition of lactic acid in the same concentration into the growth medium.

  15. FUEL CELL ENERGY RECOVERY FROM LANDFILL GAS

    EPA Science Inventory

    International Fuel Cells Corporation is conducting a US Environmental Protection Agency (EPA) sponsored program to demonstrate energy recovery from landfill gas using a commercial phosphoric acid fuel cell power plant. The US EPA is interested in fuel cells for this application b...

  16. Fuel Cell Research at NASA GRC

    NASA Technical Reports Server (NTRS)

    Perez-Davis, Marla E.; Lyons, Valerie (Technical Monitor)

    2002-01-01

    An overview of NASA GRC (Glenn Research Center) initiatives and challenges in fuel cell technology. The research and development of fuel cells and regenerative fuel cell systems for a wide variety of applications, including earth-based and planetary aircraft, spacecraft, planetary surface power, and terrestrial use are discussed.

  17. Acid electrolyte fuel cell technology program. [for application to the space shuttle orbiter

    NASA Technical Reports Server (NTRS)

    1973-01-01

    The development of an acid electrolyte fuel cell was investigated to provide a cost effective electrical power system for the space shuttle orbiter. Previous investigation showed the life capability of the fuel cell was improved by proper prehumidification of the reactant gases. Breadboard models were developed which incorporate reactant prehumidification and have a life duration time of 2000 hours. Fuel cell performance was found to be invariant with cell life, and reactant consumption was unchanged from start to end of life. Satisfactory start and stop procedures are demonstrated along with scale-up capabilities for the number of cells in a stack, and for cell active areas. Safety design features, which operate to isolate the affected module from the remainder of the system, to eliminate single point failure modes from affecting the entire electrical power system are included.

  18. Application of fuel cells with heat recovery for integrated utility systems

    NASA Technical Reports Server (NTRS)

    Shields, V.; King, J. M., Jr.

    1975-01-01

    This paper presents the results of a study of fuel cell powerplants with heat recovery for use in an integrated utility system. Such a design provides for a low pollution, noise-free, highly efficient integrated utility. Use of the waste heat from the fuel cell powerplant in an integrated utility system for the village center complex of a new community results in a reduction in resource consumption of 42 percent compared to conventional methods. In addition, the system has the potential of operating on fuels produced from waste materials (pyrolysis and digester gases); this would provide further reduction in energy consumption.

  19. Miniature ceramic fuel cell

    DOEpatents

    Lessing, Paul A.; Zuppero, Anthony C.

    1997-06-24

    A miniature power source assembly capable of providing portable electricity is provided. A preferred embodiment of the power source assembly employing a fuel tank, fuel pump and control, air pump, heat management system, power chamber, power conditioning and power storage. The power chamber utilizes a ceramic fuel cell to produce the electricity. Incoming hydro carbon fuel is automatically reformed within the power chamber. Electrochemical combustion of hydrogen then produces electricity.

  20. Operando fuel cell spectroscopy

    NASA Astrophysics Data System (ADS)

    Kendrick, Ian Michael

    unobserved peaks corresponding to adsorbed ethanol. A modification to the operando fuel cell design allowed for acquisition of Raman spectra. A confocal Raman microscope enabled characterization of the MEA through depth profiling. The potential dependent peaks of an Fe-N x/C catalyst were identified and compared to the theoretical spectra of the proposed active sites. It was determined that oxygen adsorbed onto iron/iron oxide carbon nanostructures were responsible for the experimentally obtained peaks. This finding was supported by additional Raman studies carried out on a catalyst with these active sites removed through peroxide treatments. 1 Topsoe, H., Developments in operando studies and in situ characterization of heterogeneous catalysts. Journal of Catalysis, 2003. 216(1-2): p. 155-164. 2 Stamenkovic, V., et al., Vibrational properties of CO at the Pt(111)-solution interface: the anomalous stark-tuning slope. Journal of Physical Chemistry B, 2005. 109(2): p. 678-680. 3 Kendrick, I., et al., Elucidating the Ionomer-Electrified Metal Interface. J. Am. Chem. Soc., 2010. 132(49): p. 17611-17616. 4 Lamy, C. and Leger, J.M., FUEL-CELLS - APPLICATION TO ELECTRIC VEHICLES. Journal De Physique Iv, 1994. 4(C1): p. 253-281.

  1. Solid oxide fuel cell generator

    DOEpatents

    Di Croce, A.M.; Draper, R.

    1993-11-02

    A solid oxide fuel cell generator has a plenum containing at least two rows of spaced apart, annular, axially elongated fuel cells. An electrical conductor extending between adjacent rows of fuel cells connects the fuel cells of one row in parallel with each other and in series with the fuel cells of the adjacent row. 5 figures.

  2. Solid oxide fuel cell generator

    DOEpatents

    Di Croce, A. Michael; Draper, Robert

    1993-11-02

    A solid oxide fuel cell generator has a plenum containing at least two rows of spaced apart, annular, axially elongated fuel cells. An electrical conductor extending between adjacent rows of fuel cells connects the fuel cells of one row in parallel with each other and in series with the fuel cells of the adjacent row.

  3. Analytical applications of microbial fuel cells. Part I: Biochemical oxygen demand.

    PubMed

    Abrevaya, Ximena C; Sacco, Natalia J; Bonetto, Maria C; Hilding-Ohlsson, Astrid; Cortón, Eduardo

    2015-01-15

    Microbial fuel cells (MFCs) are bio-electrochemical devices, where usually the anode (but sometimes the cathode, or both) contains microorganisms able to generate and sustain an electrochemical gradient which is used typically to generate electrical power. In the more studied set-up, the anode contains heterotrophic bacteria in anaerobic conditions, capable to oxidize organic molecules releasing protons and electrons, as well as other by-products. Released protons could reach the cathode (through a membrane or not) whereas electrons travel across an external circuit originating an easily measurable direct current flow. MFCs have been proposed fundamentally as electric power producing devices or more recently as hydrogen producing devices. Here we will review the still incipient development of analytical uses of MFCs or related devices or set-ups, in the light of a non-restrictive MFC definition, as promising tools to asset water quality or other measurable parameters. An introduction to biological based analytical methods, including bioassays and biosensors, as well as MFCs design and operating principles, will also be included. Besides, the use of MFCs as biochemical oxygen demand sensors (perhaps the main analytical application of MFCs) is discussed. In a companion review (Part 2), other new analytical applications are reviewed used for toxicity sensors, metabolic sensors, life detectors, and other proposed applications. PMID:24856922

  4. Analytical applications of microbial fuel cells. Part I: Biochemical oxygen demand.

    PubMed

    Abrevaya, Ximena C; Sacco, Natalia J; Bonetto, Maria C; Hilding-Ohlsson, Astrid; Cortón, Eduardo

    2015-01-15

    Microbial fuel cells (MFCs) are bio-electrochemical devices, where usually the anode (but sometimes the cathode, or both) contains microorganisms able to generate and sustain an electrochemical gradient which is used typically to generate electrical power. In the more studied set-up, the anode contains heterotrophic bacteria in anaerobic conditions, capable to oxidize organic molecules releasing protons and electrons, as well as other by-products. Released protons could reach the cathode (through a membrane or not) whereas electrons travel across an external circuit originating an easily measurable direct current flow. MFCs have been proposed fundamentally as electric power producing devices or more recently as hydrogen producing devices. Here we will review the still incipient development of analytical uses of MFCs or related devices or set-ups, in the light of a non-restrictive MFC definition, as promising tools to asset water quality or other measurable parameters. An introduction to biological based analytical methods, including bioassays and biosensors, as well as MFCs design and operating principles, will also be included. Besides, the use of MFCs as biochemical oxygen demand sensors (perhaps the main analytical application of MFCs) is discussed. In a companion review (Part 2), other new analytical applications are reviewed used for toxicity sensors, metabolic sensors, life detectors, and other proposed applications.

  5. Life prediction of coated and uncoated metallic interconnect for solid oxide fuel cell applications

    NASA Astrophysics Data System (ADS)

    Liu, W. N.; Sun, X.; Stephens, E.; Khaleel, M. A.

    In this paper, we present an integrated experimental and modeling methodology in predicting the life of coated and uncoated metallic interconnect (IC) for solid oxide fuel cell (SOFC) applications. The ultimate goal is to provide cell designer and manufacture with a predictive methodology such that the life of the IC system can be managed and optimized through different coating thickness to meet the overall cell designed life. Crofer 22 APU is used as the example IC material system. The life of coated and uncoated Crofer 22 APU under isothermal cooling was predicted by comparing the predicted interfacial strength and the interfacial stresses induced by the cooling process from the operating temperature to room temperature, together with the measured oxide scale growth kinetics. It was found that the interfacial strength between the oxide scale and the Crofer 22 APU substrate decreases with the growth of the oxide scale, and that the interfacial strength for the oxide scale/spinel coating interface is much higher than that of the oxide scale/Crofer 22 APU substrate interface. As expected, the predicted life of the coated Crofer 22 APU is significantly longer than that of the uncoated Crofer 22 APU.

  6. Impact of heat and water management on proton exchange membrane fuel cells degradation in automotive application

    NASA Astrophysics Data System (ADS)

    Nandjou, F.; Poirot-Crouvezier, J.-P.; Chandesris, M.; Blachot, J.-F.; Bonnaud, C.; Bultel, Y.

    2016-09-01

    In Proton Exchange Membrane Fuel Cells, local temperature is a driving force for many degradation mechanisms such as hygrothermal deformation and creep of the membrane, platinum dissolution and bipolar plates corrosion. In order to investigate and quantify those effects in automotive application, durability testing is conducted in this work. During the ageing tests, the local performance and temperature are investigated using in situ measurements of a printed circuit board. At the end of life, post-mortem analyses of the aged components are conducted. The experimental results are compared with the simulated temperature and humidity in the cell obtained from a pseudo-3D multiphysics model in order to correlate the observed degradations to the local conditions inside the stack. The primary cause of failure in automotive cycling is pinhole/crack formation in the membrane, induced by high variations of its water content over time. It is also observed that water condensation largely increases the probability of the bipolar plates corrosion while evaporation phenomena induce local deposits in the cell.

  7. Fuel cell technology for prototype logistic fuel cell mobile systems

    SciTech Connect

    Sederquist, R.A.; Garow, J.

    1995-08-01

    Under the aegis of the Advanced Research Project Agency`s family of programs to develop advanced technology for dual use applications, International Fuel Cells Corporation (IFC) is conducting a 39 month program to develop an innovative system concept for DoD Mobile Electric Power (MEP) applications. The concept is to integrate two technologies, the phosphoric acid fuel cell (PAFC) with an auto-thermal reformer (ATR), into an efficient fuel cell power plant of nominally 100-kilowatt rating which operates on logistic fuels (JP-8). The ATR fuel processor is the key to meeting requirements for MEP (including weight, volume, reliability, maintainability, efficiency, and especially operation on logistic fuels); most of the effort is devoted to ATR development. An integrated demonstration test unit culminates the program and displays the benefits of the fuel cell system, relative to the standard 100-kilowatt MEP diesel engine generator set. A successful test provides the basis for proceeding toward deployment. This paper describes the results of the first twelve months of activity during which specific program aims have remained firm.

  8. Liquid fuel cells.

    PubMed

    Soloveichik, Grigorii L

    2014-01-01

    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.

  9. Liquid fuel cells

    PubMed Central

    2014-01-01

    Summary 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. PMID:25247123

  10. Fuel Cells Vehicle Systems Analysis (Fuel Cell Freeze Investigation)

    SciTech Connect

    Pesaran, A.; Kim, G.; Markel, T.; Wipke, K.

    2005-05-01

    Presentation on Fuel Cells Vehicle Systems Analysis (Fuel Cell Freeze Investigation) for the 2005 Hydrogen, Fuel Cells & Infrastructure Technologies Program Annual Review held in Arlington, Virginia on May 23-26, 2005.

  11. Novel polybenzimidazole derivatives for high temperature polymer electrolyte membrane fuel cell applications

    NASA Astrophysics Data System (ADS)

    Xiao, Lixiang

    Recent advances have made polymer electrolyte membrane fuel cells (PEMFCs) a leading alternative to internal combustion engines for both stationary and transportation applications. In particular, high temperature polymer electrolyte membranes operational above 120°C without humidification offer many advantages including fast electrode kinetics, high tolerance to fuel impurities and simple thermal and water management systems. A series of polybenzimidazole (PBI) derivatives including pyridine-based PBI (PPBI) and sulfonated PBI (SPBI) homopolymers and copolymers have been synthesized using polyphosphoric acid (PPA) as both solvent and polycondensation agent. High molecular weight PBI derivative polymers were obtained with well controlled backbone structures in terms of pyridine ring content, polymer backbone rigidity and degree of sulfonation. A novel process, termed the PPA process, has been developed to prepare phosphoric acid (PA) doped PBI membranes by direct-casting of the PPA polymerization solution without isolation or re-dissolution of the polymers. The subsequent hydrolysis of PPA to PA by moisture absorbed from the atmosphere usually induced a transition from the solution-like state to a gel-like state and produced PA doped PBI membranes with a desirable suite of physiochemical properties characterized by the PA doping levels, mechanical properties and proton conductivities. The effects of the polymer backbone structure on the polymer characteristics and membrane properties, i.e., the structure-property relationships of the PBI derivative polymers have been studied. The incorporation of additional basic nitrogen containing pyridine rings and sulfonic acid groups enhanced the polymer solubility in acid and dipolar solvents while retaining the inherently high thermal stability of the PBI heteroaromatic backbone. In particular, the degradation of the SPBI polymers with reasonable high molecular weights commenced above 450°C, notably higher than other

  12. Fuel-Cell Water Separator

    NASA Technical Reports Server (NTRS)

    Burke, Kenneth Alan; Fisher, Caleb; Newman, Paul

    2010-01-01

    The main product of a typical fuel cell is water, and many fuel-cell configurations use the flow of excess gases (i.e., gases not consumed by the reaction) to drive the resultant water out of the cell. This two-phase mixture then exits through an exhaust port where the two fluids must again be separated to prevent the fuel cell from flooding and to facilitate the reutilization of both fluids. The Glenn Research Center (GRC) has designed, built, and tested an innovative fuel-cell water separator that not only removes liquid water from a fuel cell s exhaust ports, but does so with no moving parts or other power-consuming components. Instead it employs the potential and kinetic energies already present in the moving exhaust flow. In addition, the geometry of the separator is explicitly intended to be integrated into a fuel-cell stack, providing a direct mate with the fuel cell s existing flow ports. The separator is also fully scalable, allowing it to accommodate a wide range of water removal requirements. Multiple separators can simply be "stacked" in series or parallel to adapt to the water production/removal rate. GRC s separator accomplishes the task of water removal by coupling a high aspect- ratio flow chamber with a highly hydrophilic, polyethersulfone membrane. The hydrophilic membrane readily absorbs and transports the liquid water away from the mixture while simultaneously resisting gas penetration. The expansive flow path maximizes the interaction of the water particles with the membrane while minimizing the overall gas flow restriction. In essence, each fluid takes its corresponding path of least resistance, and the two fluids are effectively separated. The GRC fuel-cell water separator has a broad range of applications, including commercial hydrogen-air fuel cells currently being considered for power generation in automobiles.

  13. Fuel cells: Operating flexibly

    NASA Astrophysics Data System (ADS)

    Lee, Young Moo

    2016-09-01

    Fuel cells typically function well only in rather limited temperature and humidity ranges. Now, a proton exchange membrane consisting of ion pair complexes is shown to enable improved fuel cell performance under a wide range of conditions that are unattainable with conventional approaches.

  14. PLATINUM AND FUEL CELLS

    EPA Science Inventory

    Platinum requirements for fuel cell vehicles (FCVS) have been identified as a concern and possible problem with FCV market penetration. Platinum is a necessary component of the electrodes of fuel cell engines that power the vehicles. The platinum is deposited on porous electrodes...

  15. Tilted fuel cell apparatus

    DOEpatents

    Cooper, John F.; Cherepy, Nerine; Krueger, Roger L.

    2005-04-12

    Bipolar, tilted embodiments of high temperature, molten electrolyte electrochemical cells capable of directly converting carbon fuel to electrical energy are disclosed herein. The bipolar, tilted configurations minimize the electrical resistance between one cell and others connected in electrical series. The tilted configuration also allows continuous refueling of carbon fuel.

  16. 2007 Fuel Cell Technologies Market Report

    SciTech Connect

    McMurphy, K.

    2009-07-01

    The fuel cell industry, which has experienced continued increases in sales, is an emerging clean energy industry with the potential for significant growth in the stationary, portable, and transportation sectors. Fuel cells produce electricity in a highly efficient electrochemical process from a variety of fuels with low to zero emissions. This report describes data compiled in 2008 on trends in the fuel cell industry for 2007 with some comparison to two previous years. The report begins with a discussion of worldwide trends in units shipped and financing for the fuel cell industry for 2007. It continues by focusing on the North American and U.S. markets. After providing this industry-wide overview, the report identifies trends for each of the major fuel cell applications -- stationary power, portable power, and transportation -- including data on the range of fuel cell technologies -- polymer electrolyte membrane fuel cell (PEMFC), solid oxide fuel cell (SOFC), alkaline fuel cell (AFC), molten carbonate fuel cell (MCFC), phosphoric acid fuel cell (PAFC), and direct-methanol fuel cell (DMFC) -- used for these applications.

  17. Analysis of dynamic requirements for fuel cell systems for vehicle applications

    NASA Astrophysics Data System (ADS)

    Pischinger, Stefan; Schönfelder, Carsten; Ogrzewalla, Jürgen

    Conventional vehicles with internal combustion engines, as well as battery powered electric vehicles, achieve one of the most important customer requirements; achieving extremely short response times to load changes. Also, fast acceleration times from a cold start to full power in the range of seconds are practicable. New fuel cell-based propulsion systems, as well as auxiliary power units, have to fulfill the same demands to become competitive. This includes heating-up the system to operating temperature as well as the control strategy for start-up. An additional device to supply starting air is necessary, if the compressor motor can only be operated with fuel cell voltage. Since the system components (for example, the air supply or the fuel supply) are not mechanically coupled, as is the case with conventional internal combustion engines, these components have to be controlled by different sensors and actuators. This can be an advantage in optimizing the system, but it also can represent an additional challenge. This paper describes the fuel cell system requirements regarding transient operation and their dependence on system structure. In particular, the requirements for peripheral components such as air supply, fuel supply and the balance of heat in a fuel cell system are examined. Furthermore, the paper outlines the necessity of an electric storage device and its resultant capacity, which will enable faster load changes. Acceleration and deceleration of the vehicle are accomplished through the use of the electric storage device, while the fuel cell system only has to deliver the mean power consumption without higher load peaks. On the basis of system simulation, different concepts are evaluated for use as a propulsion system or APU and, then, critical components are identified. The effects of advanced control strategies regarding the dynamic behavior of the system are demonstrated. Technically, a fuel cell system could be a viable propulsion system alternative

  18. Micro-Tubular Fuel Cells

    NASA Technical Reports Server (NTRS)

    Kimble, Michael C.; Anderson, Everett B.; Jayne, Karen D.; Woodman, Alan S.

    2004-01-01

    Micro-tubular fuel cells that would operate at power levels on the order of hundreds of watts or less are under development as alternatives to batteries in numerous products - portable power tools, cellular telephones, laptop computers, portable television receivers, and small robotic vehicles, to name a few examples. Micro-tubular fuel cells exploit advances in the art of proton-exchange-membrane fuel cells. The main advantage of the micro-tubular fuel cells over the plate-and-frame fuel cells would be higher power densities: Whereas the mass and volume power densities of low-pressure hydrogen-and-oxygen-fuel plate-and-frame fuel cells designed to operate in the targeted power range are typically less than 0.1 W/g and 0.1 kW/L, micro-tubular fuel cells are expected to reach power densities much greater than 1 W/g and 1 kW/L. Because of their higher power densities, micro-tubular fuel cells would be better for powering portable equipment, and would be better suited to applications in which there are requirements for modularity to simplify maintenance or to facilitate scaling to higher power levels. The development of PEMFCs has conventionally focused on producing large stacks of cells that operate at typical power levels >5 kW. The usual approach taken to developing lower-power PEMFCs for applications like those listed above has been to simply shrink the basic plate-and-frame configuration to smaller dimensions. A conventional plate-and-frame fuel cell contains a membrane/electrode assembly in the form of a flat membrane with electrodes of the same active area bonded to both faces. In order to provide reactants to both electrodes, bipolar plates that contain flow passages are placed on both electrodes. The mass and volume overhead of the bipolar plates amounts to about 75 percent of the total mass and volume of a fuel-cell stack. Removing these bipolar plates in the micro-tubular fuel cell significantly increases the power density.

  19. An Investigation to Resolve the Interaction Between Fuel Cell, Power Conditioning System and Application Loads

    SciTech Connect

    Sudip K. Mazumder

    2005-12-31

    Development of high-performance and durable solidoxide fuel cells (SOFCs) and a SOFC power-generating system requires knowledge of the feedback effects from the power-conditioning electronics and from application-electrical-power circuits that may pass through or excite the power-electronics subsystem (PES). Therefore, it is important to develop analytical models and methodologies, which can be used to investigate and mitigate the effects of the electrical feedbacks from the PES and the application loads (ALs) on the reliability and performance of SOFC systems for stationary and non-stationary applications. However, any such attempt to resolve the electrical impacts of the PES on the SOFC would be incomplete unless one utilizes a comprehensive analysis, which takes into account the interactions of SOFC, PES, balance-of-plant system (BOPS), and ALs as a whole. SOFCs respond quickly to changes in load and exhibit high part- and full-load efficiencies due to its rapid electrochemistry, which is not true for the thermal and mechanical time constants of the BOPS, where load-following time constants are, typically, several orders of magnitude higher. This dichotomy can affect the lifetime and durability of the SOFCSs and limit the applicability of SOFC systems for load-varying stationary and transportation applications. Furthermore, without validated analytical models and investigative design and optimization methodologies, realizations of cost-effective, reliable, and optimal PESs (and power-management controls), in particular, and SOFC systems, in general, are difficult. On the whole, the research effort can lead to (a) cost-constrained optimal PES design for high-performance SOFCS and high energy efficiency and power density, (b) effective SOFC power-system design, analyses, and optimization, and (c) controllers and modulation schemes for mitigation of electrical impacts and wider-stability margin and enhanced system efficiency.

  20. CLIMATE CHANGE FUEL CELL PROGRAM

    SciTech Connect

    Mike Walneuski

    2004-09-16

    ChevronTexaco has successfully operated a 200 kW PC25C phosphoric acid fuel cell power plant at the corporate data center in San Ramon, California for the past two years and seven months following installation in December 2001. This site was chosen based on the ability to utilize the combined heat (hot water) and power generation capability of this modular fuel cell power plant in an office park setting . In addition, this project also represents one of the first commercial applications of a stationary fuel cell for a mission critical data center to assess power reliability benefits. This fuel cell power plant system has demonstrated outstanding reliability and performance relative to other comparably sized cogeneration systems.

  1. Analysis and design of solid oxide fuel cell for railroad applications

    NASA Astrophysics Data System (ADS)

    Kothapally, Adarsh Srivatsav

    Solid oxide fuel cell (SOFC) is a direct chemical-to-electrical energy conversion system using hydrogen and oxygen as reactants, operating at a higher temperature range (800°--1100° C). With the advantages of low-cost materials for anode, cathode, membrane, and the versatility in the use of various types of fuels as compared to other fuel cell types, the SOFC is one of the most recommendable fuel cells for large power generating system. An additional distinct advantage is of using the hot exhaust by-product gases to generate electricity in an advance combined power generation system along with a gas turbine. The objective of the present work is to analyze a tri-layer SOFC using a two-dimensional simulation model. This work was concerned with the evaluation of different fuel cell losses, heat generation, and determining the performance polarization of the SOFC using in-house computer code. The operation characteristics were evaluated with a wide spectrum of cell parameters and operating conditions. Further, a 1-MW SOFC is designed for a locomotive engine based on the selected operating characteristics and using the state-of-the-art SOFC materials.

  2. Business Case for a Micro-Combined Heat and Power Fuel Cell System in Commercial Applications

    SciTech Connect

    Brooks, Kriston P.; Makhmalbaf, Atefe; Anderson, David M.; Amaya, Jodi P.; Pilli, Siva Prasad; Srivastava, Viraj; Upton, Jaki F.

    2013-10-30

    Combined heat and power fuel cell systems (CHP-FCSs) provide consistent electrical power and hot water with greater efficiency and lower emissions than alternative sources. These systems can be used either as baseload, grid-connected, or as off-the-grid power sources. This report presents a business case for CHP-FCSs in the range of 5 to 50 kWe. Systems in this power range are considered micro-CHP-FCS. For this particular business case, commercial applications rather than residential or industrial are targeted. To understand the benefits of implementing a micro-CHP-FCS, the characteristics that determine their competitive advantage must first be identified. Locations with high electricity prices and low natural gas prices are ideal locations for micro-CHP-FCSs. Fortunately, these high spark spread locations are generally in the northeastern area of the United States and California where government incentives are already in place to offset the current high cost of the micro-CHP-FCSs. As a result of the inherently high efficiency of a fuel cell and their ability to use the waste heat that is generated as a CHP, they have higher efficiency. This results in lower fuel costs than comparable alternative small-scale power systems (e.g., microturbines and reciprocating engines). A variety of markets should consider micro-CHP-FCSs including those that require both heat and baseload electricity throughout the year. In addition, the reliable power of micro-CHP-FCSs could be beneficial to markets where electrical outages are especially frequent or costly. Greenhouse gas emission levels from micro-CHP-FCSs are 69 percent lower, and the human health costs are 99.9 percent lower, than those attributed to conventional coal-fired power plants. As a result, FCSs can allow a company to advertise as environmentally conscious and provide a bottom-line sales advantage. As a new technology in the early stages of adoption, micro-CHP-FCSs are currently more expensive than alternative

  3. Fuel economy of hydrogen fuel cell vehicles

    NASA Astrophysics Data System (ADS)

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

    On the basis of on-road energy consumption, fuel economy (FE) of hydrogen fuel cell light-duty vehicles is projected to be 2.5-2.7 times the fuel economy of the conventional gasoline internal combustion engine vehicles (ICEV) on the same platforms. Even with a less efficient but higher power density 0.6 V per cell than the base case 0.7 V per cell at the rated power point, the hydrogen fuel cell vehicles are projected to offer essentially the same fuel economy multiplier. The key to obtaining high fuel economy as measured on standardized urban and highway drive schedules lies in maintaining high efficiency of the fuel cell (FC) system at low loads. To achieve this, besides a high performance fuel cell stack, low parasitic losses in the air management system (i.e., turndown and part load efficiencies of the compressor-expander module) are critical.

  4. Fuel cells. Citations from the NTIS data base

    NASA Astrophysics Data System (ADS)

    Cavagnaro, D. M.

    1980-08-01

    Fuel cell applications, components, fabrication, design, catalysts, and chemistry are covered. The citations discuss different types of fuel cells such as hydrogen oxygen cells, hydrocarbon air cells, and biochemical cells.

  5. Fuel cell stack arrangements

    DOEpatents

    Kothmann, Richard E.; Somers, Edward V.

    1982-01-01

    Arrangements of stacks of fuel cells and ducts, for fuel cells operating with separate fuel, oxidant and coolant streams. An even number of stacks are arranged generally end-to-end in a loop. Ducts located at the juncture of consecutive stacks of the loop feed oxidant or fuel to or from the two consecutive stacks, each individual duct communicating with two stacks. A coolant fluid flows from outside the loop, into and through cooling channels of the stack, and is discharged into an enclosure duct formed within the loop by the stacks and seals at the junctures at the stacks.

  6. Molybdenum dioxide-based anode for solid oxide fuel cell applications

    NASA Astrophysics Data System (ADS)

    Kwon, Byeong Wan; Ellefson, Caleb; Breit, Joe; Kim, Jinsoo; Grant Norton, M.; Ha, Su

    2013-12-01

    The present paper describes the fabrication and performance of a molybdenum dioxide (MoO2)-based anode for liquid hydrocarbon/oxygenated hydrocarbon-fueled solid oxide fuel cells (SOFCs). These fuel cells first internally reform the complex liquid fuel into carbon fragments and hydrogen, which are then electrochemically oxidized to produce electrical energy without external fuel processors. The MoO2-based anode was fabricated on to an yttria-stabilized zirconia (YSZ) electrolyte via combined electrostatic spray deposition (ESD) and direct painting methods. The cell performance was measured by directly feeding liquid fuels such as n-dodecane (i.e., a model diesel/kerosene fuel) or biodiesel (i.e., a future biomass-based liquid fuel) to the MoO2-based anode at 850 °C. The maximum initial power densities obtained from our MoO2-based SOFC were 34 mW cm-2 and 45 mW cm-2 using n-dodecane and biodiesel, respectively. The initial power density of the MoO2-based SOFC was improved up to 2500 mW cm-2 by optimizing the porosity of the MoO2-based anode. To test the long-term stability of the MoO2-based anode SOFC against coking, n-dodecane was continuously fed into the cell for 24 h at the open circuit voltage (OCV). During long-term testing, voltage-current density (V-I) plots were periodically obtained and they showed no significant changes over the operation time. Microstructural examination of the tested cells indicated that the MoO2-based anode displayed negligible coke formation, which explains its stability. On the other hand, SOFCs with conventional nickel (Ni)-based anodes under the same operating conditions showed a significant amount of coke formation on the metal surface, which led to a rapid drop in cell performance. Hence, the present work demonstrates that MoO2-based anodes exhibit outstanding tolerance to coke formation. This result opens up the opportunity for more efficiently generating electrical energy from both existing transportation and next generation

  7. One pot electrochemical synthesis of polymer/CNT/metal nanoparticles for fuel cell applications

    NASA Astrophysics Data System (ADS)

    Ventrapragada, Lakshman; Zhu, Jingyi; Karakaya, Mehmet; Podila, Ramakrishna; Rao, Apparao; Clemson Nanomaterials center Team

    Carbon nanotubes (CNTs) have become a key player in the design of materials for energy applications. They gained their popularity in industrial and scientific research due to their unique properties like excellent conductivity, high surface area, etc. Here we used chemical vapor deposition (CVD) to synthesize two types of CNTs namely, helically coiled CNTs and vertically aligned CNTs. These CNTs were subsequently used to make composites with conducting polymers and metal nanoparticles. One pot electrochemical synthesis was designed to electropolymerize aniline, pyrrole etc. on the surface of the electrode with simultaneous deposition of platinum and gold metal nanoparticles, and CNTs in the polymer matrix. The as synthesized composite materials were characterized with scanning electron microscope for surface morphology and spectroscopic techniques like Raman, UV-Vis for functionality. These were used to study electrocatalytic oxidation of methanol and ethanol for alkaline fuel cell applications. Electrodes fabricated from these composites not only showed good kinetics but also exhibited excellent stability. Uniqueness of this composite lies in its simple two step synthesis and it doesn't involve any surfactants unlike conventional chemical synthesis routes.

  8. Pendant dual sulfonated poly(arylene ether ketone) proton exchange membranes for fuel cell application

    NASA Astrophysics Data System (ADS)

    Nguyen, Minh Dat Thinh; Yang, Sungwoo; Kim, Dukjoon

    2016-10-01

    Poly(arylene ether ketone) (PAEK) possessing carboxylic groups at the pendant position is synthesized, and the substitution degree of pendant carboxylic groups is controlled by adjusting the ratio of 4,4-bis(4-hydroxyphenyl)valeric acid and 2,2-bis(4-hydroxyphenyl)propane. Dual sulfonated 3,3-diphenylpropylamine (SDPA) is grafted onto PAEK as a proton-conducting moiety via the amidation reaction with carboxylic groups. The transparent and flexible membranes with different degrees of sulfonation are fabricated so that we can test and compare their structure and properties with a commercial Nafion® 115 membrane for PEMFC applications. All prepared PAEK-SDPA membranes exhibit good oxidative and hydrolytic stability from Fenton's and high temperature water immersion test. SAXS analysis illustrates an excellent phase separation between the hydrophobic backbone and hydrophilic pendant groups, resulting in big ionic clusters. The proton conductivity was measured at different relative humidity, and its behavior was analyzed by hydration number of the membrane. Among a series of membranes, some samples (including B20V80-SDPA) show not only higher proton conductivity, but also higher integrated cell performance than those of Nafion® 115 at 100% relative humidity, and thus we expect these to be good candidate membranes for proton exchange membrane fuel cells (PEMFCs).

  9. Current-fed Step-up DC/DC Converter for Fuel Cell Applications with Active Overvoltage Clamping

    NASA Astrophysics Data System (ADS)

    Andreiciks, Aleksandrs; Steiks, Ingars; Krievs, Oskars

    2010-01-01

    In order to use hydrogen fuel cells in domestic applications either as main power supply or backup source, their low DC output voltage has to be matched to the level and frequency of the utility grid AC voltage. Such power converter systems usually consist of a DC-DC converter and a DC-AC inverter. A double inductor step-up push-pull converter is investigated in this paper, presenting simulation and experimental results for passive and active overvoltage clamping. The prototype of the investigated converter is elaborated for 1200 W power to match the rated power of the proton exchange membrane (PEM) fuel cell located in hydrogen fuel cell research laboratory.

  10. Fuel cell water transport

    DOEpatents

    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.

  11. A sizing-design methodology for hybrid fuel cell power systems and its application to an unmanned underwater vehicle

    NASA Astrophysics Data System (ADS)

    Cai, Q.; Brett, D. J. L.; Browning, D.; Brandon, N. P.

    Hybridizing a fuel cell with an energy storage unit (battery or supercapacitor) combines the advantages of each device to deliver a system with high efficiency, low emissions, and extended operation compared to a purely fuel cell or battery/supercapacitor system. However, the benefits of such a system can only be realised if the system is properly designed and sized, based on the technologies available and the application involved. In this work we present a sizing-design methodology for hybridisation of a fuel cell with a battery or supercapacitor for applications with a cyclic load profile with two discrete power levels. As an example of the method's application, the design process for selecting the energy storage technology, sizing it for the application, and determining the fuel load/range limitations, is given for an unmanned underwater vehicle (UUV). A system level mass and energy balance shows that hydrogen and oxygen storage systems dominate the mass and volume of the energy system and consequently dictate the size and maximum mission duration of a UUV.

  12. Rejuvenation of automotive fuel cells

    DOEpatents

    Kim, Yu Seung; Langlois, David A.

    2016-08-23

    A process for rejuvenating fuel cells has been demonstrated to improve the performance of polymer exchange membrane fuel cells with platinum/ionomer electrodes. The process involves dehydrating a fuel cell and exposing at least the cathode of the fuel cell to dry gas (nitrogen, for example) at a temperature higher than the operating temperature of the fuel cell. The process may be used to prolong the operating lifetime of an automotive fuel cell.

  13. Trial operation of a phosphoric acid fuel cell (PC25) for CHP applications in Europe

    SciTech Connect

    Uhrig, M.; Droste, W.; Wolf, D.

    1996-12-31

    In Europe, ten 200 kW phosphoric acid fuel cells (PAFCs) produced by ONSI (PC25) are currently in operation. Their operators collaborate closely in the European Fuel Cell Users Group (EFCUG). The experience gained from trial operation by the four German operators - HEAG, HGW/HEW, Thyssengas and Ruhrgas - coincides with that of the other European operators. This experience can generally be regarded as favourable. With a view to using fuel cells in combined heat and power generation (CHP), the project described in this report, which was carried out in cooperation with the municipal utility of Bochum and Gasunie of the Netherlands, aimed at gaining experience with the PC 25 in field operation under the specific operating conditions prevailing in Europe. The work packages included heat-controlled operation, examination of plant behavior with varying gas properties and measurement of emissions under dynamic load conditions. The project received EU funding under the JOULE programme.

  14. A high voltage ratio and low ripple interleaved DC-DC converter for fuel cell applications.

    PubMed

    Chang, Long-Yi; Chao, Kuei-Hsiang; Chang, Tsang-Chih

    2012-01-01

    This paper proposes a high voltage ratio and low ripple interleaved boost DC-DC converter, which can be used to reduce the output voltage ripple. This converter transfers the low DC voltage of fuel cell to high DC voltage in DC link. The structure of the converter is parallel with two voltage-doubler boost converters by interleaving their output voltages to reduce the voltage ripple ratio. Besides, it can lower the current stress for the switches and inductors in the system. First, the PSIM software was used to establish a proton exchange membrane fuel cell and a converter circuit model. The simulated and measured results of the fuel cell output characteristic curve are made to verify the correctness of the established simulation model. In addition, some experimental results are made to validate the effectiveness in improving output voltage ripple of the proposed high voltage ratio interleaved boost DC-DC converters.

  15. A high voltage ratio and low ripple interleaved DC-DC converter for fuel cell applications.

    PubMed

    Chang, Long-Yi; Chao, Kuei-Hsiang; Chang, Tsang-Chih

    2012-01-01

    This paper proposes a high voltage ratio and low ripple interleaved boost DC-DC converter, which can be used to reduce the output voltage ripple. This converter transfers the low DC voltage of fuel cell to high DC voltage in DC link. The structure of the converter is parallel with two voltage-doubler boost converters by interleaving their output voltages to reduce the voltage ripple ratio. Besides, it can lower the current stress for the switches and inductors in the system. First, the PSIM software was used to establish a proton exchange membrane fuel cell and a converter circuit model. The simulated and measured results of the fuel cell output characteristic curve are made to verify the correctness of the established simulation model. In addition, some experimental results are made to validate the effectiveness in improving output voltage ripple of the proposed high voltage ratio interleaved boost DC-DC converters. PMID:23365536

  16. Colorimetric determination of phosphoric acid leakage for phosphoric acid-doped polybenzimidazole membrane fuel cell applications

    NASA Astrophysics Data System (ADS)

    Jeong, Yeon Hun; Jung, Ju Hae; Choi, Euiji; Han, Seungyoon; Begley, Alina Irene; Yoo, Sung Jong; Jang, Jong Hyun; Kim, Hyoung-Juhn; Nam, Suk Woo; Lee, Kwan-Young; Kim, Jin Young

    2015-12-01

    A simple and precise colorimetric method for analyzing phosphoric acid leakage in phosphoric acid-doped polybenzimidazole membrane fuel cells is described. The developed method is based on the colorimetric determination from a rapid formation of molybdenum blue color by the reduction reaction of molybdate ions in the presence of phosphoric acid in the acidic medium. The color is stable up to a few months and can be used for the sensitive and accurate detection of phosphoric acid electrolyte which is discharged from the fuel cell during operation. Tests with a wide concentration range of phosphate compounds showed that it permits determination of phosphoric acid up to nanogram quantities. The developed detection method assists monitoring the phosphoric acid contents and developing stable operation strategies of fuel cells.

  17. A High Voltage Ratio and Low Ripple Interleaved DC-DC Converter for Fuel Cell Applications

    PubMed Central

    Chang, Long-Yi; Chao, Kuei-Hsiang; Chang, Tsang-Chih

    2012-01-01

    This paper proposes a high voltage ratio and low ripple interleaved boost DC-DC converter, which can be used to reduce the output voltage ripple. This converter transfers the low DC voltage of fuel cell to high DC voltage in DC link. The structure of the converter is parallel with two voltage-doubler boost converters by interleaving their output voltages to reduce the voltage ripple ratio. Besides, it can lower the current stress for the switches and inductors in the system. First, the PSIM software was used to establish a proton exchange membrane fuel cell and a converter circuit model. The simulated and measured results of the fuel cell output characteristic curve are made to verify the correctness of the established simulation model. In addition, some experimental results are made to validate the effectiveness in improving output voltage ripple of the proposed high voltage ratio interleaved boost DC-DC converters. PMID:23365536

  18. The application of Dow Chemical's perfluorinated membranes in proton-exchange membrane fuel cells

    NASA Technical Reports Server (NTRS)

    Eisman, G. A.

    1989-01-01

    Dow Chemical's research activities in fuel cells revolve around the development of perfluorosulfonic acid membranes useful as the proton transport medium and separator. Some of the performance characteristics which are typical for such membranes are outlined. The results of tests utilizing a new experimental membrane useful in proton-exchange membrane fuel cells are presented. The high voltage at low current densities can lead to higher system efficiencies while, at the same time, not sacrificing other critical properties pertinent to membrane fuel cell operation. A series of tests to determine response times indicated that on-off cycles are on the order of 80 milliseconds to reach 90 percent of full power. The IR free voltage at 100 amps/sq ft was determined and the results indicating a membrane/electrode package resistance to be .15 ohm-sq cm at 100 amps/sq ft.

  19. High efficiency direct fuel cell hybrid power cycle for near term application

    SciTech Connect

    Steinfeld, G.; Maru, H.C.; Sanderson, R.A.

    1996-12-31

    Direct carbonate fuel cells being developed by Energy Research Corporation can generate power at an efficiency approaching 60% LHV. This unique fuel cell technology can consume natural gas and other hydrocarbon based fuels directly without requiring an external reformer, thus providing a simpler and inherently efficient power generation system. A 2 MW power plant demonstration of this technology has been initiated at an installation in the city of Santa Clara in California. A 2.85 MW commercial configuration shown in Figure 1 is presently being developed. The complete plant includes the carbonate fuel cell modules, an inverter, transformer and switchgear, a heat recovery unit and supporting instrument air and water treatment systems. The emission levels for this 2.85 MW plant are projected to be orders of magnitude below existing or proposed standards. The 30 year levelized cost of electricity, without inflation, is projected to be approximately 5{cents}/kW-h assuming capital cost for the carbonate fuel cell system of $1000/kW.

  20. A small portable proton exchange membrane fuel cell and hydrogen generator for medical applications.

    PubMed

    Adlhart, O J; Rohonyi, P; Modroukas, D; Driller, J

    1997-01-01

    Small, lightweight power sources for total artificial hearts (TAH), left ventricular assist devices (LVAD), and other medical products are under development. The new power source will provide 2 to 3 times the capacity of conventional batteries. The implications of this new power source are profound. For example, for the Heartmate LVAD, 5 to 8 hours of operation are obtained with 3 lb of lead acid batteries (Personal Communication Mr. Craig Sherman, Thermo Cardiosystems, Inc TCI 11/29/96). With the same weight, as much as 14 hours of operation appear achievable with the proton exchange membrane (PEM) fuel cell power source. Energy densities near 135 watt-hour/L are achievable. These values significantly exceed those of most conventional and advanced primary and secondary batteries. The improvement is mission dependent and even applies for the short deployment cited above. The comparison to batteries becomes even more favorable if the mission length is increased. The higher capacity requires only replacement of lightweight hydride cartridges and logistically available water. Therefore, when one spare 50 L hydride cartridge weighing 115 g is added to the reactant supply the energy density of the total system increases to 230 watt-hour/kg. This new power source is comprised of a hydrogen fueled, air-breathing PEM fuel cell and a miniature hydrogen generator (US Patent No 5,514,353). The fuel cell is of novel construction and differs from conventional bipolar PEM fuel cells by the arrangement of cells on a single sheet of ion-exchange membrane. The construction avoids the weight and volume penalty of conventional bipolar stacks. The hydrogen consumed by the fuel cell is generated load-responsively in the miniature hydrogen generator, by reacting calcium hydride with water, forming in the process hydrogen and lime. The generator is cartridge rechargeable and available in capacities providing up to several hundred watt-hours of electric power.

  1. Internet Fuel Cells Forum

    SciTech Connect

    Sudhoff, Frederick A.

    1996-08-01

    The rapid development and integration of the Internet into the mainstream of professional life provides the fuel cell industry with the opportunity to share new ideas with unprecedented capabilities. The U.S. Department of Energy's (DOE's) Morgantown Energy Technology Center (METC) has undertaken the task to maintain a Fuel Cell Forum on the Internet. Here, members can exchange ideas and information pertaining to fuel cell technologies. The purpose of this forum is to promote a better understanding of fuel cell concepts, terminology, processes, and issues relating to commercialization of fuel cell power technology. The Forum was developed by METC to provide those interested with fuel cell conference information for its current concept of exchanging ideas and information pertaining to fuel cells. Last August, the Forum expanded to an on-line and world-wide network. There are 250 members, and membership is growing at a rate of several new subscribers per week. The forum currently provides updated conference information and interactive information exchange. Forum membership is encouraged from utilities, industry, universities, and government. Because of the public nature of the internet, business sensitive, confidential, or proprietary information should not be placed on this system. The Forum is unmoderated; therefore, the views and opinions of authors expressed in the forum do not necessarily state or reflect those of the U.S. government or METC.

  2. Development of Sensors and Sensing Technology for Hydrogen Fuel Cell Vehicle Applications

    SciTech Connect

    Brosha, E L; Sekhar, P K; Mukundan, R; Williamson, T; Garzon, F H; Woo, L Y; Glass, R R

    2010-01-06

    One related area of hydrogen fuel cell vehicle (FCV) development that cannot be overlooked is the anticipated requirement for new sensors for both the monitoring and control of the fuel cell's systems and for those devices that will be required for safety. Present day automobiles have dozens of sensors on-board including those for IC engine management/control, sensors for state-of-health monitoring/control of emissions systems, sensors for control of active safety systems, sensors for triggering passive safety systems, and sensors for more mundane tasks such as fluids level monitoring to name the more obvious. The number of sensors continues to grow every few years as a result of safety mandates but also in response to consumer demands for new conveniences and safety features. Some of these devices (e.g. yaw sensors for dynamic stability control systems or tire presure warning RF-based devices) may be used on fuel cell vehicles without any modification. However the use of hydrogen as a fuel will dictate the development of completely new technologies for such requirements as the detection of hydrogen leaks, sensors and systems to continuously monitor hydrogen fuel purity and protect the fuel cell stack from poisoning, and for the important, yet often taken for granted, tasks such as determining the state of charge of the hydrogen fuel storage and delivery system. Two such sensors that rely on different transduction mechanisms will be highlighted in this presentation. The first is an electrochemical device for monitoring hydrogen levels in air. The other technology covered in this work, is an acoustic-based approach to determine the state of charge of a hydride storage system.

  3. Research and development of Proton-Exchange-Membrane (PEM) fuel cell system for transportation applications. Fuel cell infrastructure and commercialization study

    SciTech Connect

    1996-11-01

    This paper has been prepared in partial fulfillment of a subcontract from the Allison Division of General Motors under the terms of Allison`s contract with the U.S. Department of Energy (DE-AC02-90CH10435). The objective of this task (The Fuel Cell Infrastructure and Commercialization Study) is to describe and prepare preliminary evaluations of the processes which will be required to develop fuel cell engines for commercial and private vehicles. This report summarizes the work undertaken on this study. It addresses the availability of the infrastructure (services, energy supplies) and the benefits of creating public/private alliances to accelerate their commercialization. The Allison prime contract includes other tasks related to the research and development of advanced solid polymer fuel cell engines and preparation of a demonstration automotive vehicle. The commercialization process starts when there is sufficient understanding of a fuel cell engine`s technology and markets to initiate preparation of a business plan. The business plan will identify each major step in the design of fuel cell (or electrochemical) engines, evaluation of the markets, acquisition of manufacturing facilities, and the technical and financial resources which will be required. The process will end when one or more companies have successfully developed and produced fuel cell engines at a profit. This study addressed the status of the information which will be required to prepare business plans, develop the economic and market acceptance data, and to identify the mobility, energy and environment benefits of electrochemical or fuel cell engines. It provides the reader with information on the status of fuel cell or electrochemical engine development and their relative advantages over competitive propulsion systems. Recommendations and descriptions of additional technical and business evaluations that are to be developed in more detail in Phase II, are included.

  4. AN INVESTIGATION TO RESOLVE THE INTERACTION BETWEEN FUEL CELL, POWER CONDITIONING SYSTEM AND APPLICATION LOADS

    SciTech Connect

    Sudip K. Mazumder; Chuck McKintyre; Dan Herbison; Doug Nelson; Comas Haynes; Michael von Spakovsky; Joseph Hartvigsen; S. Elangovan

    2003-11-03

    Solid-Oxide Fuel Cell (SOFC) stacks respond quickly to changes in load and exhibit high part- and full-load efficiencies due to its rapid electrochemistry. However, this is not true for the thermal, mechanical, and chemical balance-of-plant subsystem (BOPS), where load-following time constants are, typically, several orders of magnitude higher. This dichotomy diminishes the reliability and performance of the electrode with increasing demand of load. Because these unwanted phenomena are not well understood, the manufacturers of SOFC use conservative schemes (such as, delayed load-following to compensate for slow BOPS response or expensive inductor filtering) to control stack responses to load variations. This limits the applicability of SOFC systems for load-varying stationary and transportation applications from a cost standpoint. Thus, a need exists for the synthesis of component- and system-level models of SOFC power-conditioning systems and the development of methodologies for investigating the system-interaction issues (which reduce the lifetime and efficiency of a SOFC) and optimizing the responses of each subsystem, leading to optimal designs of power-conditioning electronics and optimal control strategies, which mitigate the electrical-feedback effects. Equally important are ''multiresolution'' finite-element modeling and simulation studies, which can predict the impact of changes in system-level variables (e.g., current ripple and load-transients) on the local current densities, voltages, and temperature (these parameters are very difficult or cumbersome, if not impossible to obtain) within a SOFC cell. Towards that end, for phase I of this project, sponsored by the U.S. DOE (NETL), we investigate the interactions among fuel cell, power-conditioning system, and application loads and their effects on SOFC reliability (durability) and performance. A number of methodologies have been used in Phase I to develop the steady-state and transient nonlinear models of

  5. PEM regenerative fuel cells

    NASA Technical Reports Server (NTRS)

    Swette, Larry L.; Laconti, Anthony B.; Mccatty, Stephen A.

    1993-01-01

    This paper will update the progress in developing electrocatalyst systems and electrode structures primarily for the positive electrode of single-unit solid polymer proton exchange membrane (PEM) regenerative fuel cells. The work was done with DuPont Nafion 117 in complete fuel cells (40 sq cm electrodes). The cells were operated alternately in fuel cell mode and electrolysis mode at 80 C. In fuel cell mode, humidified hydrogen and oxygen were supplied at 207 kPa (30 psi); in electrolysis mode, water was pumped over the positive electrode and the gases were evolved at ambient pressure. Cycling data will be presented for Pt-Ir catalysts and limited bifunctional data will be presented for Pt, Ir, Ru, Rh, and Na(x)Pt3O4 catalysts as well as for electrode structure variations.

  6. The TMI regenerable solid oxide fuel cell

    NASA Technical Reports Server (NTRS)

    Cable, Thomas L.

    1995-01-01

    Energy storage and production in space requires rugged, reliable hardware which minimizes weight, volume, and maintenance while maximizing power output and usable energy storage. 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

  7. Performance of a square, cross-corrugated, polymer film, compact, heat-exchanger with potential application in fuel cells

    NASA Astrophysics Data System (ADS)

    Zaheed, L.; Jachuck, R. J. J.

    This paper describes an experimental investigation of the performance characteristics of a novel, cross-corrugated, polymer film, compact, heat-exchanger (PFCHE) made from poly ether ether ketone (PEEK). The aim is to develop Jh and f correlations over a range of Reynolds numbers under laminar conditions to be used in alternative heat-exchanger designs for potential applications in the fuel-cell industry. The incentive for adopting these designs is the huge weight, energy and cost savings involved. Design correlations for square units are key tools in obtaining alternative designs for applications that are presently monopolized by metallic heat-exchangers. The design correlations are establised and then used to perform case studies in selected applications in the fuel-cell industry to suit the fluids and the configuration.

  8. Fuel Cells: Reshaping the Future

    ERIC Educational Resources Information Center

    Toay, Leo

    2004-01-01

    In conjunction with the FreedomCAR (Cooperative Automotive Research) and Fuel Initiative, President George W. Bush has pledged nearly two billion dollars for fuel cell research. Chrysler, Ford, and General Motors have unveiled fuel cell demonstration vehicles, and all three of these companies have invested heavily in fuel cell research. Fuel cell…

  9. Fuel cell generator energy dissipator

    DOEpatents

    Veyo, Stephen Emery; Dederer, Jeffrey Todd; Gordon, John Thomas; Shockling, Larry Anthony

    2000-01-01

    An apparatus and method are disclosed for eliminating the chemical energy of fuel remaining in a fuel cell generator when the electrical power output of the fuel cell generator is terminated. During a generator shut down condition, electrically resistive elements are automatically connected across the fuel cell generator terminals in order to draw current, thereby depleting the fuel

  10. "Dedicated To The Continued Education, Training and Demonstration of PEM Fuel Cell Powered Lift Trucks In Real-World Applications."

    SciTech Connect

    Dever, Thomas J.

    2011-11-29

    The project objective was to further assist in the commercialization of fuel cell and H2 technology by building further upon the successful fuel cell lift truck deployments that were executed by LiftOne in 2007, with longer deployments of this technology in real-world applications. We involved facilities management, operators, maintenance personnel, safety groups, and Authorities Having Jurisdiction. LiftOne strived to educate a broad group from many areas of industry and the community as to the benefits of this technology. Included were First Responders from the local areas. We conducted month long deployments with end-users to validate the value proposition and the market requirements for fuel cell powered lift trucks. Management, lift truck operators, Authorities Having Jurisdiction and the general public experienced 'hands on' fuel cell experience in the material handling applications. We partnered with Hydrogenics in the execution of the deployment segment of the program. Air Products supplied the compressed H2 gas and the mobile fueler. Data from the Fuel Cell Power Packs and the mobile fueler was sent to the DOE and NREL as required. Also, LiftOne conducted the H2 Education Seminars on a rotating basis at their locations for lift trucks users and for other selected segments of the community over the project's 36 month duration. Executive Summary The technology employed during the deployments program was not new, as the equipment had been used in several previous demos and early adoptions within the material handling industry. This was the case with the new HyPx Series PEM - Fuel Cell Power Packs used, which had been demo'd before during the 2007 Greater Columbia Fuel Cell Challenge. The Air Products HF-150 Fueler was used outdoors during the deployments and had similarly been used for many previous demo programs. The methods used centered on providing this technology as the power for electric sit-down lift trucks at high profile companies operating large

  11. Copper nitride nanocubes: size-controlled synthesis and application as cathode catalyst in alkaline fuel cells.

    PubMed

    Wu, Haibin; Chen, Wei

    2011-10-01

    Copper nitride nanocubes are synthesized in a facile one-phase process. The crystal size could be tuned easily by using different primary amines as capping agents. Such Pt-free nanocrystals exhibit electrocatalytic activity toward oxygen reduction and appear to be promising cathodic electrocatalysts in alkaline fuel cells. PMID:21894995

  12. Fuel Cell Animation

    NASA Video Gallery

    Oxygen (O2) and hydrogen (H2) migrate into the fuel cell. The oxygen molecules migrate to the catalyst where the anode strips some of their electrons. This allows them to move through the cathode a...

  13. Diamond and Hydrogenated Carbons for Advanced Batteries and Fuel Cells: Fundamental Studies and Applications.

    SciTech Connect

    Swain; Greg M.

    2009-04-13

    The original funding under this project number was awarded for a period 12/1999 until 12/2002 under the project title Diamond and Hydrogenated Carbons for Advanced Batteries and Fuel Cells: Fundamental Studies and Applications. The project was extended until 06/2003 at which time a renewal proposal was awarded for a period 06/2003 until 06/2008 under the project title Metal/Diamond Composite Thin-Film Electrodes: New Carbon Supported Catalytic Electrodes. The work under DE-FG02-01ER15120 was initiated about the time the PI moved his research group from the Department of Chemistry at Utah State University to the Department of Chemistry at Michigan State University. This DOE-funded research was focused on (i) understanding structure-function relationships at boron-doped diamond thin-film electrodes, (ii) understanding metal phase formation on diamond thin films and developing electrochemical approaches for producing highly dispersed electrocatalyst particles (e.g., Pt) of small nominal particle size, (iii) studying the electrochemical activity of the electrocatalytic electrodes for hydrogen oxidation and oxygen reduction and (iv) conducting the initial synthesis of high surface area diamond powders and evaluating their electrical and electrochemical properties when mixed with a Teflon binder.

  14. Oxidation Resistance of Low Carbon Stainless Steel for Applications in Solid Oxide Fuel Cells

    SciTech Connect

    Ziomek-Moroz, Margaret; Covino, Bernard S., Jr.; Holcomb, Gordon R.; Cramer, Stephen D.; Bullard, Sophie J.; Matthes, Steven A.; Dunning, John S.; Alman, David E.; Singh, P.

    2003-10-01

    Alloys protected from corrosion by Cr2O3 (chromia) are recognized as potential replacements for LaCrO3–based ceramic materials currently used as bipolar separators (interconnects) in solid oxide fuel cells (SOFC). Stainless steels gain their corrosion resistance from the formation of chromia, when exposed to oxygen at elevated temperatures. Materials for interconnect applications must form uniform conductive oxide scales at 600–800o C while simultaneously exposed to air on the cathode side and mixtures of H2 - H2O, and, possibly, CHx and CO - CO2 on the anode side. In addition, they must possess good physical, mechanical, and thermal properties. Type 316L stainless steel was selected for the baseline study and development of an understanding of corrosion processes in complex gas environments. This paper discusses the oxidation resistance of 316L stainless steel exposed to dual SOFC environment for ~100 hours at ~900oK. The dual environment consisted of dry air on the cathode side of the specimen and a mixture of H2 and 3% H2O on the anode side. Post - corrosion surface evaluation involved the use of optical and scanning electron microscopy and x-ray diffraction analyses.

  15. Facile Multiscale Patterning by Creep-Assisted Sequential Imprinting and Fuel Cell Application.

    PubMed

    Jang, Segeun; Kim, Minhyoung; Kang, Yun Sik; Choi, Yong Whan; Kim, Sang Moon; Sung, Yung-Eun; Choi, Mansoo

    2016-05-11

    The capability of fabricating multiscale structures with desired morphology and incorporating them into engineering applications is key to realizing technological breakthroughs by employing the benefits from both microscale and nanoscale morphology simultaneously. Here, we developed a facile patterning method to fabricate multiscale hierarchical structures by a novel approach called creep-assisted sequential imprinting. In this work, nanopatterning was first carried out by thermal imprint lithography above the glass transition temperature (Tg) of a polymer film, and then followed by creep-assisted imprinting with micropatterns based on the mechanical deformation of the polymer film under the relatively long-term exposure to mechanical stress at temperatures below the Tg of the polymer. The fabricated multiscale arrays exhibited excellent pattern uniformity over large areas. To demonstrate the usage of multiscale architectures, we incorporated the multiscale Nafion films into polymer electrolyte membrane fuel cell, and this device showed more than 10% higher performance than the conventional one. The enhancement was attributed to the decrease in mass transport resistance because of unique cone-shape morphology by creep-recovery effects and the increase in interfacial surface area between Nafion film and electrocatalyst layer. PMID:27116979

  16. Development and validation of a slurry model for chemical hydrogen storage in fuel cell vehicle applications

    NASA Astrophysics Data System (ADS)

    Brooks, Kriston P.; Pires, Richard P.; Simmons, Kevin L.

    2014-12-01

    The U.S. Department of Energy's (DOE) Hydrogen Storage Engineering Center of Excellence (HSECoE) is developing models for hydrogen storage systems for fuel cell-based light duty vehicle applications for a variety of promising materials. These transient models simulate the performance of the storage system for comparison to the DOE's Technical Targets and a set of four drive cycles. PNNL developed models to simulate the performance and suitability of slurry-based chemical hydrogen storage materials. The storage systems of both a representative exothermic system based on ammonia borane and an endothermic system based on alane were developed and modeled in Simulink®. Once complete, the reactor and radiator components of the model were validated with experimental data. The system design parameters were adjusted to allow the model to successfully meet a highway cycle, an aggressive cycle, a cold-start cycle, and a hot drive cycle. Finally, a sensitivity analysis was performed to identify the range of material properties where these DOE targets and drive cycles could be met. Materials with a heat of reaction >11 kJ mol-1 H2 generated and a slurry hydrogen capacity of >11.4% will meet the on-board efficiency and gravimetric capacity targets, respectively.

  17. Coproduction of acetic acid and electricity by application of microbial fuel cell technology to vinegar fermentation.

    PubMed

    Tanino, Takanori; Nara, Youhei; Tsujiguchi, Takuya; Ohshima, Takayuki

    2013-08-01

    The coproduction of a useful material and electricity via a novel application of microbial fuel cell (MFC) technology to oxidative fermentation was investigated. We focused on vinegar production, i.e., acetic acid fermentation, as an initial and model useful material that can be produced by oxidative fermentation in combination with MFC technology. The coproduction of acetic acid and electricity by applying MFC technology was successfully demonstrated by the simultaneous progress of acetic acid fermentation and electricity generation through a series of repeated batch fermentations. Although the production rate of acetic acid was very small, it increased with the number of repeated batch fermentations that were conducted. We obtained nearly identical (73.1%) or larger (89.9%) acetic acid yields than that typically achieved by aerated fermentation (75.8%). The open-cycle voltages measured before and after fermentation increased with the total fermentation time and reached a maximum value of 0.521 V prior to the third batch fermentation. The maximum current and power densities measured in this study (19.1 μA/cm² and 2.47 μW/cm², respectively) were obtained after the second batch fermentation.

  18. Robust DC/DC converter control for polymer electrolyte membrane fuel cell application

    NASA Astrophysics Data System (ADS)

    Wang, Ya-Xiong; Yu, Duck-Hyun; Chen, Shi-An; Kim, Young-Bae

    2014-09-01

    This study investigates a robust controller in regulating the pulse width modulation (PWM) of a DC/DC converter for a polymer electrolyte membrane fuel cell (PEMFC) application. A significant variation in the output voltage of a PEMFC depends on the power requirement and prevents a PEMFC from directly connecting to a subsequent power bus. DC/DC converters are utilized to step-up or step-down voltage to match the subsequent power bus voltage. In this study, a full dynamic model, which includes a PEMFC and boost and buck DC/DC converters, is developed under MATLAB/Simulink environment for control. A robust PWM duty ratio control for the converters is designed using time delay control (TDC). This control enables state variables to accurately follow the dynamics of a reference model using time-delayed information of plant input and output information within a few sampling periods. To prove the superiority of the TDC performance, traditional proportional-integral control (PIC) and model predictive control (MPC) are designed and implemented, and the simulation results are compared. The efficacies of TDC for the PEMFC-fed PWM DC/DC converters are validated through experimental test results using a 100 W PEMFC as well as boost and buck DC/DC converters.

  19. Microbial fuel cells and microbial ecology: applications in ruminant health and production research.

    PubMed

    Bretschger, Orianna; Osterstock, Jason B; Pinchak, William E; Ishii, Shun'ichi; Nelson, Karen E

    2010-04-01

    Microbial fuel cell (MFC) systems employ the catalytic activity of microbes to produce electricity from the oxidation of organic, and in some cases inorganic, substrates. MFC systems have been primarily explored for their use in bioremediation and bioenergy applications; however, these systems also offer a unique strategy for the cultivation of synergistic microbial communities. It has been hypothesized that the mechanism(s) of microbial electron transfer that enable electricity production in MFCs may be a cooperative strategy within mixed microbial consortia that is associated with, or is an alternative to, interspecies hydrogen (H(2)) transfer. Microbial fermentation processes and methanogenesis in ruminant animals are highly dependent on the consumption and production of H(2)in the rumen. Given the crucial role that H(2) plays in ruminant digestion, it is desirable to understand the microbial relationships that control H(2) partial pressures within the rumen; MFCs may serve as unique tools for studying this complex ecological system. Further, MFC systems offer a novel approach to studying biofilms that form under different redox conditions and may be applied to achieve a greater understanding of how microbial biofilms impact animal health. Here, we present a brief summary of the efforts made towards understanding rumen microbial ecology, microbial biofilms related to animal health, and how MFCs may be further applied in ruminant research.

  20. Development and Validation of a Slurry Model for Chemical Hydrogen Storage in Fuel Cell Applications

    SciTech Connect

    Brooks, Kriston P.; Pires, Richard P.; Simmons, Kevin L.

    2014-07-25

    The US Department of Energy's (DOE) Hydrogen Storage Engineering Center of Excellence (HSECoE) is developing models for hydrogen storage systems for fuel cell-based light duty vehicle applications for a variety of promising materials. These transient models simulate the performance of the storage system for comparison to the DOE’s Technical Targets and a set of four drive cycles. The purpose of this research is to describe the models developed for slurry-based chemical hydrogen storage materials. The storage systems of both a representative exothermic system based on ammonia borane and endothermic system based on alane were developed and modeled in Simulink®. Once complete the reactor and radiator components of the model were validated with experimental data. The model was then run using a highway cycle, an aggressive cycle, cold-start cycle and hot drive cycle. The system design was adjusted to meet these drive cycles. A sensitivity analysis was then performed to identify the range of material properties where these DOE targets and drive cycles could be met. Materials with a heat of reaction greater than 11 kJ/mol H2 generated and a slurry hydrogen capacity of greater than 11.4% will meet the on-board efficiency and gravimetric capacity targets, respectively.

  1. Microbial Fuel Cells and Microbial Ecology: Applications in Ruminant Health and Production Research

    PubMed Central

    Osterstock, Jason B.; Pinchak, William E.; Ishii, Shun’ichi; Nelson, Karen E.

    2009-01-01

    Microbial fuel cell (MFC) systems employ the catalytic activity of microbes to produce electricity from the oxidation of organic, and in some cases inorganic, substrates. MFC systems have been primarily explored for their use in bioremediation and bioenergy applications; however, these systems also offer a unique strategy for the cultivation of synergistic microbial communities. It has been hypothesized that the mechanism(s) of microbial electron transfer that enable electricity production in MFCs may be a cooperative strategy within mixed microbial consortia that is associated with, or is an alternative to, interspecies hydrogen (H2) transfer. Microbial fermentation processes and methanogenesis in ruminant animals are highly dependent on the consumption and production of H2in the rumen. Given the crucial role that H2 plays in ruminant digestion, it is desirable to understand the microbial relationships that control H2 partial pressures within the rumen; MFCs may serve as unique tools for studying this complex ecological system. Further, MFC systems offer a novel approach to studying biofilms that form under different redox conditions and may be applied to achieve a greater understanding of how microbial biofilms impact animal health. Here, we present a brief summary of the efforts made towards understanding rumen microbial ecology, microbial biofilms related to animal health, and how MFCs may be further applied in ruminant research. PMID:20024685

  2. NMR studies of methanol transport in membranes for fuel cell applications.

    SciTech Connect

    Every, H. A.; Zawodzinski, T. A. , Jr.

    2001-01-01

    Characterization of the methanol diffusion process in Nafion 117 was achieved with the use of a modified pulsed field gradient NMR technique. To ensure that the concentration of methanol was constant throughout the entire experiment, the membrane was continually immersed in the methanol solution. When using the standard pulsed field gradient NMR method, the diffusion of the methanol in the membrane is strongly influenced by the diffusion of methanol in solution. Application of a filter gradient suppresses the signal from the methanol in solution, enabling the methanol diffusion in the membrane to be observed unambiguously. Complete suppression of the solution signal was achieved when a 60% filter gradient was employed. Under such circumstances, the coefficient for diffusion of methanol within the membrane was calculated to be 4x10-6cm2s-1, which is similar to the values reported in the literature. Consequently, the use of NMR filter gradient measurements is a valid method for studying the diffusion coefficient of methanol within fuel cell membranes.

  3. Rapidly refuelable fuel cell

    DOEpatents

    Joy, Richard W.

    1983-01-01

    This invention is directed to a metal-air fuel cell where the consumable metal anode is movably positioned in the cell and an expandable enclosure, or bladder, is used to press the anode into contact with separating spacers between the cell electrodes. The bladder may be depressurized to allow replacement of the anode when consumed.

  4. Composite fuel cell membranes

    DOEpatents

    Plowman, Keith R.; Rehg, Timothy J.; Davis, Larry W.; Carl, William P.; Cisar, Alan J.; Eastland, Charles S.

    1997-01-01

    A bilayer or trilayer composite ion exchange membrane suitable for use in a fuel cell. The composite membrane has a high equivalent weight thick layer in order to provide sufficient strength and low equivalent weight surface layers for improved electrical performance in a fuel cell. In use, the composite membrane is provided with electrode surface layers. The composite membrane can be composed of a sulfonic fluoropolymer in both core and surface layers.

  5. Composite fuel cell membranes

    DOEpatents

    Plowman, K.R.; Rehg, T.J.; Davis, L.W.; Carl, W.P.; Cisar, A.J.; Eastland, C.S.

    1997-08-05

    A bilayer or trilayer composite ion exchange membrane is described suitable for use in a fuel cell. The composite membrane has a high equivalent weight thick layer in order to provide sufficient strength and low equivalent weight surface layers for improved electrical performance in a fuel cell. In use, the composite membrane is provided with electrode surface layers. The composite membrane can be composed of a sulfonic fluoropolymer in both core and surface layers.

  6. Compliant fuel cell system

    DOEpatents

    Bourgeois, Richard Scott; Gudlavalleti, Sauri

    2009-12-15

    A fuel cell assembly comprising at least one metallic component, at least one ceramic component and a structure disposed between the metallic component and the ceramic component. The structure is configured to have a lower stiffness compared to at least one of the metallic component and the ceramic component, to accommodate a difference in strain between the metallic component and the ceramic component of the fuel cell assembly.

  7. Application of infiltrated LSCM-GDC oxide anode in direct carbon/coal fuel cells.

    PubMed

    Yue, Xiangling; Arenillas, Ana; Irvine, John T S

    2016-08-15

    Hybrid direct carbon/coal fuel cells (HDCFCs) utilise an anode based upon a molten carbonate salt with an oxide conducting solid electrolyte for direct carbon/coal conversion. They can be fuelled by a wide range of carbon sources, and offer higher potential chemical to electrical energy conversion efficiency and have the potential to decrease CO2 emissions compared to coal-fired power plants. In this study, the application of (La, Sr)(Cr, Mn)O3 (LSCM) and (Gd, Ce)O2 (GDC) oxide anodes was explored in a HDCFC system running with two different carbon fuels, an organic xerogel and a raw bituminous coal. The electrochemical performance of the HDCFC based on a 1-2 mm thick 8 mol% yttria stabilised zirconia (YSZ) electrolyte and the GDC-LSCM anode fabricated by wet impregnation procedures was characterized and discussed. The infiltrated oxide anode showed a significantly higher performance than the conventional Ni-YSZ anode, without suffering from impurity formation under HDCFC operation conditions. Total polarisation resistance (Rp) reached 0.8-0.9 Ω cm(2) from DCFC with an oxide anode on xerogel and bituminous coal at 750 °C, with open circuit voltage (OCV) values in the range 1.1-1.2 V on both carbon forms. These indicated the potential application of LSCM-GDC oxide anode in HDCFCs. The chemical compatibility of LSCM/GDC with carbon/carbonate investigation revealed the emergence of an A2BO4 type oxide in place of an ABO3 perovskite structure in the LSCM in a reducing environment, due to Li attack as a result of intimate contact between the LSCM and Li2CO3, with GDC being stable under identical conditions. Such reaction between LSCM and Li2CO3 was not observed on a LSCM-YSZ pellet treated with Li-K carbonate in 5% H2/Ar at 700 °C, nor on a GDC-LSCM anode after HDCFC operation. The HDCFC durability tests of GDC-LSCM oxide on a xerogel and on raw bituminous coal were performed under potentiostatic operation at 0.7 V at 750 °C. The degradation mechanisms were

  8. Application of infiltrated LSCM-GDC oxide anode in direct carbon/coal fuel cells.

    PubMed

    Yue, Xiangling; Arenillas, Ana; Irvine, John T S

    2016-08-15

    Hybrid direct carbon/coal fuel cells (HDCFCs) utilise an anode based upon a molten carbonate salt with an oxide conducting solid electrolyte for direct carbon/coal conversion. They can be fuelled by a wide range of carbon sources, and offer higher potential chemical to electrical energy conversion efficiency and have the potential to decrease CO2 emissions compared to coal-fired power plants. In this study, the application of (La, Sr)(Cr, Mn)O3 (LSCM) and (Gd, Ce)O2 (GDC) oxide anodes was explored in a HDCFC system running with two different carbon fuels, an organic xerogel and a raw bituminous coal. The electrochemical performance of the HDCFC based on a 1-2 mm thick 8 mol% yttria stabilised zirconia (YSZ) electrolyte and the GDC-LSCM anode fabricated by wet impregnation procedures was characterized and discussed. The infiltrated oxide anode showed a significantly higher performance than the conventional Ni-YSZ anode, without suffering from impurity formation under HDCFC operation conditions. Total polarisation resistance (Rp) reached 0.8-0.9 Ω cm(2) from DCFC with an oxide anode on xerogel and bituminous coal at 750 °C, with open circuit voltage (OCV) values in the range 1.1-1.2 V on both carbon forms. These indicated the potential application of LSCM-GDC oxide anode in HDCFCs. The chemical compatibility of LSCM/GDC with carbon/carbonate investigation revealed the emergence of an A2BO4 type oxide in place of an ABO3 perovskite structure in the LSCM in a reducing environment, due to Li attack as a result of intimate contact between the LSCM and Li2CO3, with GDC being stable under identical conditions. Such reaction between LSCM and Li2CO3 was not observed on a LSCM-YSZ pellet treated with Li-K carbonate in 5% H2/Ar at 700 °C, nor on a GDC-LSCM anode after HDCFC operation. The HDCFC durability tests of GDC-LSCM oxide on a xerogel and on raw bituminous coal were performed under potentiostatic operation at 0.7 V at 750 °C. The degradation mechanisms were

  9. Proazaphosphatranes: Versatile molecules with applications in fuel cell technology, biodiesel production and important organic transformations

    NASA Astrophysics Data System (ADS)

    Wadhwa, Kuldeep

    In recent years proazaphosphatranes of type P(RNCH2CH 2)3N have proven their synthetic utility as catalysts and as stoichiometric bases in a variety of organic transformations. Several reports from our group appeared in which the use of proazaphosphatranes for the activation of the silicon to synthesize useful organic intermediates. Herein we report the use of proazaphosphatranes to synthesize various useful small organic molecules by the activation of Si-O and Si-C bonds, along with efforts to gain evidence for silicon group activation. We previously demonstrated that a phosphatranium cation for which the counter anion is nitrate, is an excellent catalyst for aza- and thia-Michael reactions. Evidence was presented that such a nitrate salt in which the cation was bound to a solid support was superior to a commercially available nitrate anion exchange resin. These results prompted us to chemically bind phosphatranium salts to NafionRTM membrane supports to function as nitrate and hydroxide ion conducting membranes for fuel cell applications. Here we report the synthesis of a novel anion exchange fuel cell membrane by chemically attaching proazaphosphatranium and phosphatranium cations under microwave conditions to the sulfonic groups of Nafion-F RTM and the use of solid-state NMR techniques to determine the structure and composition of this anion exchange membrane. A thermally and air stable derivative of a proazaphosphatrane i.e., a benzyl azidoproazaphosphatrane, was discovered in our laboratory which was shown to be an excellent catalyst for biodiesel synthesis via the transesterification of soybean oil and for other Lewis base- catalyzed important organic transformations. However, the heterogeneous analog i.e., a Merrifield resin-bound azidoproazaphosphatrane, was found to be deactivated after 11 cycles for the transesterification of soybean oil. We report here an attempted synthesis of a TeflonRTM - and NafionRTM-bound azidoproazaphosphatrane. Such a solid

  10. Research and development of Proton-Exchange Membrane (PEM) fuel cell system for transportation applications: Initial conceptual design report

    NASA Astrophysics Data System (ADS)

    1993-11-01

    This report addresses Task 1.1, model development and application, and Task 1.2, vehicle mission definition. Overall intent is to produce a methanol-fueled 10-kW power source and to evaluate electrochemical engine (ECE) use in transportation. Major achievements include development of an ECE power source model and its integration into a comprehensive power source/electric vehicle propulsion model, establishment of candidate FCV (fuel cell powered electric vehicle) mission requirements, initial FCV studies, and a candidate FCV recommendation for further study.

  11. Research and Development of Proton-Exchange Membrane (PEM) Fuel Cell System for Transportation Applications: Initial Conceptual Design Report

    SciTech Connect

    Not Available

    1993-11-30

    This report addresses Task 1.1, model development and application, and Task 1.2, vehicle mission definition. Overall intent is to produce a methanol-fueled 10-kW power source, and to evaluate electrochemical engine (ECE) use in transportation. Major achievements include development of an ECE power source model and its integration into a comprehensive power source/electric vehicle propulsion model, establishment of candidate FCV (fuel cell powered electric vehicle) mission requirements, initial FCV studies, and a candidate FCV recommendation for further study.

  12. Fuel dissipater for pressurized fuel cell generators

    DOEpatents

    Basel, Richard A.; King, John E.

    2003-11-04

    An apparatus and method are disclosed for eliminating the chemical energy of fuel remaining in a pressurized fuel cell generator (10) when the electrical power output of the fuel cell generator is terminated during transient operation, such as a shutdown; where, two electrically resistive elements (two of 28, 53, 54, 55) at least one of which is connected in parallel, in association with contactors (26, 57, 58, 59), a multi-point settable sensor relay (23) and a circuit breaker (24), are automatically connected across the fuel cell generator terminals (21, 22) at two or more contact points, in order to draw current, thereby depleting the fuel inventory in the generator.

  13. Metal decoration of exfoliated graphite nanoplatelets (xGnP) for fuel cell application

    NASA Astrophysics Data System (ADS)

    Do, In-Hwan

    The synthesis and characterization of metal particles at nanometer length scale has been the object of much research in modern nanotechnology due to their great impact on new nanoscale scientific and technological applications. Nanoscale metal particles possess unique optical, thermal, electronic, magnetic properties and chemical reactivity since the size of the resulting materials is on the same order as the fundamental interaction distances that give rise to physical properties and thus shows the quantum size effect which is not observed in their bulky status. Therefore, an effective synthetic method is required to obtain uniform small metal powders with controlled size and a narrow size distribution and also to produce nanocomposites consisting of either metals or metal oxides supported on carbons or metals dispersed on metal oxides for a variety of applications in chemical industries, automobiles, energy and power generating devices, hydrogen economy as well as for sensors. On the other hand, although their excellent mechanical, thermal and electrical conductivity, excellent corrosion and oxidation resistance, and low impurity levels which are required as a breakthrough material to increase performance of next generation energy devices, exfoliated graphite nanoplatelet (xGnP) has not been studied as deeply as recent new nano structured carbon materials such as single wall carbon nanotubes (SWNT), multi-wall carbon nanotubes (MWNT), carbon nanohorn (CNH), graphite nanofiber (GNF), and fullerenes. In addition, xGnP is much cost-effective compared to other carbon nanostructures. Hence, it is interesting to evaluate the applicability of xGnP as a support material for fuel cell which is one of promising energy devices for the future. In this research, a new simple, efficient and economic way is presented for the synthesis of noble metal nanoparticles such as Pt, Ru, Pd, etc and their deposition on various carbon supports and metal oxides via microwave heating in the

  14. A comparative study on life cycle analysis of molten carbon fuel cells and diesel engines for marine application

    NASA Astrophysics Data System (ADS)

    Alkaner, Selim; Zhou, Peilin

    The study performed a life cycle assessment (LCA) of a molten carbonate fuel cell (MCFC) plant for marine applications. The results are compared to a benchmark conventional diesel engine (DE) which operates as an auxiliary power generating unit. The LCA includes manufacturing of MCFC and DE, fuel supply, operation and decommissioning stages of the system's life cycle. As a new technology in its very early stages of commercialisation, some detailed data for the FC systems are not available. In order to overcome this problem, a series of scenario analysis has also been performed to evaluate the effect of various factors on the overall impact, such as change in power load factors and effect of recycling credit at the end of life cycle. Environmental benefits from fuel cell operation are maximised with the use of hydrogen as an input fuel. For the manufacturing stage of the life cycle, input material and process energy required for fuel cell stack assemblies and balance-of-plants (BOP) represent a bigger impact than that of conventional benchmark mainly due to special materials used in the stack and the weights of the BOP components. Additionally, recovering valuable materials through re-use or re-cycle will reduce the overall environmental burden of the system over its life cycle.

  15. Characterization of direct methanol fuel cell (DMFC) applications with H 2SO 4 modified chitosan membrane

    NASA Astrophysics Data System (ADS)

    Osifo, Peter O.; Masala, Aluwani

    Chitosan (Chs) flakes were prepared from chitin materials that were extracted from the exoskeleton of Cape rock lobsters in South Africa. The Chs flakes were prepared into membranes and the Chs membranes were modified by cross-linking with H 2SO 4. The cross-linked Chs membranes were characterized for the application in direct methanol fuel cells. The Chs membrane characteristics such as water uptake, thermal stability, proton resistance and methanol permeability were compared to that of high performance conventional Nafion 117 membranes. Under the temperature range studied 20-60 °C, the membrane water uptake for Chs was found to be higher than that of Nafion. Thermal analysis revealed that Chs membranes could withstand temperature as high as 230 °C whereas Nafion 117 membranes were stable to 320 °C under nitrogen. Nafion 117 membranes were found to exhibit high proton resistance of 284 s cm -1 than Chs membranes of 204 s cm -1. The proton fluxes across the membranes were 2.73 mol cm -2 s -1 for Chs- and 1.12 mol cm -2 s -1 Nafion membranes. Methanol (MeOH) permeability through Chs membrane was less, 1.4 × 10 -6 cm 2 s -1 for Chs membranes and 3.9 × 10 -6 cm 2 s -1 for Nafion 117 membranes at 20 °C. Chs and Nafion membranes were fabricated into membrane electrode assemblies (MAE) and their performances measure in a free-breathing commercial single cell DMFC. The Nafion membranes showed a better performance as the power density determined for Nafion membranes of 0.0075 W cm -2 was 2.7 times higher than in the case of Chs MEA.

  16. 2009 Fuel Cell Market Report

    SciTech Connect

    Vincent, Bill; Gangi, Jennifer; Curtin, Sandra; Delmont, Elizabeth

    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.

  17. Fuel cell cogeneration

    SciTech Connect

    Wimer, J.G.; Archer, D.

    1995-08-01

    The U.S. Department of Energy`s Morgantown Energy Technology Center (METC) sponsors the research and development of engineered systems which utilize domestic fuel supplies while achieving high standards of efficiency, economy, and environmental performance. Fuel cell systems are among the promising electric power generation systems that METC is currently developing. Buildings account for 36 percent of U.S. primary energy consumption. Cogeneration systems for commercial buildings represent an early market opportunity for fuel cells. Seventeen percent of all commercial buildings are office buildings, and large office buildings are projected to be one of the biggest, fastest-growing sectors in the commercial building cogeneration market. The main objective of this study is to explore the early market opportunity for fuel cells in large office buildings and determine the conditions in which they can compete with alternative systems. Some preliminary results and conclusions are presented, although the study is still in progress.

  18. Self-humidified proton exchange membrane fuel cells: Operation of larger cells and fuel cell stacks

    SciTech Connect

    Dhar, H.P.; Lee, J.H.; Lewinski, K.A.

    1996-12-31

    The PEM fuel cell is promising as the power source for use in mobile and stationary applications primarily because of its high power density, all solid components, and simplicity of operation. For wide acceptability of this power source, its cost has to be competitive with the presently available energy sources. The fuel cell requires continuous humidification during operation as a power source. The humidification unit however, increases fuel cell volume, weight, and therefore decreases its overall power density. Great advantages in terms of further fuel cell simplification can be achieved if the humidification process can be eliminated or minimized. In addition, cost reductions are associated with the case of manufacturing and operation. At BCS Technology we have developed a technology of self-humidified operation of PEM fuel cells based on the mass balance of the reactants and products and the ability of membrane electrode assembly (MEA) to retain water necessary for humidification under the cell operating conditions. The reactants enter the fuel cell chambers without carrying any form of water, whether in liquid or vapor form. Basic principles of self-humidified operation of fuel cells as practiced by BCS Technology, Inc. have been presented previously in literature. Here, we report the operation of larger self-humidified single cells and fuel cell stacks. Fuel cells of areas Up to 100 cm{sup 2} have been operated. We also show the self-humidified operation of fuel cell stacks of 50 and 100 cm{sup 2} electrode areas.

  19. Water balance in fuel cells systems.

    SciTech Connect

    Kopasz, J.; Ahmed, S.; Kumar, R.; Krumpelt, M.

    2002-01-10

    Fuel cell systems are attractive for their high efficiency (i.e., electric power generated per weight/volume of fuel,) and lower emissions. These systems are being developed for applications that include transportation (propulsion and auxiliary), remote stationary, and portable. Where these systems use on-board fuel processing of available fuels, the fuel processor requires high-purity water. For utility applications, this water may be available on-site, but for most applications, the process water must be recovered from the fuel cell system exhaust gas. For such applications, it is critically important that the fuel cell system be a net water-producing device. A variety of environmental conditions (e.g., ambient temperature, pressure), fuel cell system design, and operating conditions determine whether the fuel cell system is water-producing or water-consuming. This paper will review and discuss the conditions that determine the net-water balance of a generic fuel cell system and identify some options that will help meet the water needs of the fuel processor.

  20. Novel Application of Carbonate Fuel Cell for Capturing Carbon Dioxide from Flue Gas Streams

    SciTech Connect

    Jolly, Stephen; Ghezel-Ayagh, Hossein; Willman, Carl; Patel, Dilip; DiNitto, M.; Marina, Olga A.; Pederson, Larry R.; Steen, William A.

    2015-09-30

    To address concerns about climate change resulting from emission of CO2 by coal-fueled power plants, FuelCell Energy, Inc. has developed the Combined Electric Power and Carbon-dioxide Separation (CEPACS) system concept. The CEPACS system utilizes Electrochemical Membrane (ECM) technology derived from the Company’s Direct FuelCell® products. The system separates the CO2 from the flue gas of other plants and produces electric power using a supplementary fuel. FCE is currently evaluating the use of ECM to cost effectively separate CO2 from the flue gas of Pulverized Coal (PC) power plants under a U.S. Department of Energy contract. The overarching objective of the project is to verify that the ECM can achieve at least 90% CO2 capture from the flue gas with no more than 35% increase in the cost of electricity. The project activities include: 1) laboratory scale operational and performance tests of a membrane assembly, 2) performance tests of the membrane to evaluate the effects of impurities present in the coal plant flue gas, in collaboration with Pacific Northwest National Laboratory, 3) techno-economic analysis for an ECM-based CO2 capture system applied to a 550 MW existing PC plant, in partnership with URS Corporation, and 4) bench scale (11.7 m2 area) testing of an ECM-based CO2 separation and purification system.

  1. Thermal Transport in Porous Media with Application to Fuel Cell Diffusion Media and Metal Foams

    NASA Astrophysics Data System (ADS)

    Sadeghi, Ehsan

    Transport phenomena in high porosity open-cell fibrous structures have been the focus of many recent industrial and academic investigations. Unique features of these structures such as relatively low cost, ultra-low density, high surface area to volume ratio, and the ability to mix the passing fluid make them excellent candidates for a variety of thermofluid applications including fuel cells, compact heat exchangers and cooling of microelectronics. This thesis contributes to improved understanding of thermal transport phenomena in fuel cell gas diffusion layers (GDLs) and metal foams and describes new experimental techniques and analytic models to characterize and predict effective transport properties. Heat transfer through the GDL is a key process in the design and operation of a proton exchange membrane (PEM) fuel cell. The analysis of this process requires determination of the effective thermal conductivity as well as the thermal contact resistance (TCR) associated with the interface between the GDL and adjacent surfaces/ layers. The effective thermal conductivity significantly differs in through-plane and in-plane directions due to anisotropy of the GDL micro-structure. Also, the high porosity of GDLs makes the contribution of TCR against the heat flow through the medium more pronounced. A test bed was designed and built to measure the thermal contact resistance and effective thermal conductivity in both through-plane and in-plane directions under vacuum and ambient conditions. The developed experimental program allows the separation of effective thermal conductivity and thermal contact resistance. For GDLs, measurements are performed under a wide range of compressive loads using Toray carbon paper samples. To study the effect of cyclic compression, which may happen during the operation of a fuel cell stack, measurements are performed on the thermal and structural properties of GDL at different loading-unloading cycles. The static compression measurements are

  2. Fuel cell system

    DOEpatents

    Early, Jack; Kaufman, Arthur; Stawsky, Alfred

    1982-01-01

    A fuel cell system is comprised of a fuel cell module including sub-stacks of series-connected fuel cells, the sub-stacks being held together in a stacked arrangement with cold plates of a cooling means located between the sub-stacks to function as electrical terminals. The anode and cathode terminals of the sub-stacks are connected in parallel by means of the coolant manifolds which electrically connect selected cold plates. The system may comprise a plurality of the fuel cell modules connected in series. The sub-stacks are designed to provide a voltage output equivalent to the desired voltage demand of a low voltage, high current DC load such as an electrolytic cell to be driven by the fuel cell system. This arrangement in conjunction with switching means can be used to drive a DC electrical load with a total voltage output selected to match that of the load being driven. This arrangement eliminates the need for expensive voltage regulation equipment.

  3. Fuel processor for fuel cell power system

    DOEpatents

    Vanderborgh, Nicholas E.; Springer, Thomas E.; Huff, James R.

    1987-01-01

    A catalytic organic fuel processing apparatus, which can be used in a fuel cell power system, contains within a housing a catalyst chamber, a variable speed fan, and a combustion chamber. Vaporized organic fuel is circulated by the fan past the combustion chamber with which it is in indirect heat exchange relationship. The heated vaporized organic fuel enters a catalyst bed where it is converted into a desired product such as hydrogen needed to power the fuel cell. During periods of high demand, air is injected upstream of the combustion chamber and organic fuel injection means to burn with some of the organic fuel on the outside of the combustion chamber, and thus be in direct heat exchange relation with the organic fuel going into the catalyst bed.

  4. Ni2P Makes Application of the PtRu Catalyst Much Stronger in Direct Methanol Fuel Cells.

    PubMed

    Chang, Jinfa; Feng, Ligang; Liu, Changpeng; Xing, Wei

    2015-10-12

    PtRu is regarded as the best catalyst for direct methanol fuel cells, but the performance decay resulting from the loss of Ru seriously hinders commercial applications. Herein, we demonstrated that the presence of Ni2 P largely reduces Ru loss, which thus makes the application of PtRu much stronger in direct methanol fuel cells. Outstanding catalytic activity and stability were observed by cyclic voltammetry. Upon integrating the catalyst material into a practical direct methanol fuel cell, the highest maximum power density was achieved on the PtRu-Ni2P/C catalyst among the reference catalysts at different temperatures. A maximum power density of 69.9 mW cm(-2) at 30 °C was obtained on PtRu-Ni2P/C, which is even higher than the power density of the state-of-the-art commercial PtRu catalyst at 70 °C (63.1 mW cm(-2)). Moreover, decay in the performance resulting from Ru loss was greatly reduced owing to the presence of Ni2 P, which is indicative of very promising applications.

  5. Phosphoric Acid Fuel Cell Technology Status

    NASA Technical Reports Server (NTRS)

    Simons, S. N.; King, R. B.; Prokopius, P. R.

    1981-01-01

    A review of the current phosphoric acid fuel cell system technology development efforts is presented both for multimegawatt systems for electric utility applications and for multikilowatt systems for on-site integrated energy system applications. Improving fuel cell performance, reducing cost, and increasing durability are the technology drivers at this time. Electrodes, matrices, intercell cooling, bipolar/separator plates, electrolyte management, and fuel selection are discussed.

  6. Development of sensors and sensing technology for hydrogen fuel cell vehicle applications

    SciTech Connect

    Brosha, Eric L; Sekhar, Praveen K; Mukundan, Rangchary; Williamson, Todd L; Barzon, Fernando H; Woo, Leta Y; Glass, Robert S

    2010-01-01

    One related area of hydrogen fuel cell vehicle (FCV) development that cannot be overlooked is the anticipated requirement for new sensors for both the monitoring and control of the fuel cell's systems and for those devices that will be required for safety. Present day automobiles have dozens of sensors on-board including those for IC engine management/control, sensors for state-of-health monitoring/control of emissions systems, sensors for control of active safety systems, sensors for triggering passive safety systems, and sensors for more mundane tasks such as fluids level monitoring to name the more obvious. The number of sensors continues to grow every few years as a result of safety mandates but also in response to consumer demands for new conveniences and safety features.

  7. Processing of LaCrO{sub 3} for solid oxide fuel cell applications

    SciTech Connect

    Huebner, W.; Nasrallah, M.M.; Anderson, H.U.

    1993-11-01

    Objectives of this project is to produce LaCrO{sub 3} for the interconnect in solid oxide fuel cells. The project is divided into three areas: reproducible powder synthesis, sintering of LaCrO{sub 3}-based powders, and co-sintering of LaCrO{sub 3}-based powders with cathode and electrolyte materials. The project has been in place for 3 months; construction is underway for the spray pyrolysis system and studies initiated on the organometallic precursor.

  8. Development of alkaline fuel cells.

    SciTech Connect

    Hibbs, Michael R.; Jenkins, Janelle E.; Alam, Todd Michael; Janarthanan, Rajeswari; Horan, James L.; Caire, Benjamin R.; Ziegler, Zachary C.; Herring, Andrew M.; Yang, Yuan; Zuo, Xiaobing; Robson, Michael H.; Artyushkova, Kateryna; Patterson, Wendy; Atanassov, Plamen Borissov

    2013-09-01

    This project focuses on the development and demonstration of anion exchange membrane (AEM) fuel cells for portable power applications. Novel polymeric anion exchange membranes and ionomers with high chemical stabilities were prepared characterized by researchers at Sandia National Laboratories. Durable, non-precious metal catalysts were prepared by Dr. Plamen Atanassovs research group at the University of New Mexico by utilizing an aerosol-based process to prepare templated nano-structures. Dr. Andy Herrings group at the Colorado School of Mines combined all of these materials to fabricate and test membrane electrode assemblies for single cell testing in a methanol-fueled alkaline system. The highest power density achieved in this study was 54 mW/cm2 which was 90% of the project target and the highest reported power density for a direct methanol alkaline fuel cell.

  9. Exploration of alloy 441 chemistry for solid oxide fuel cell interconnect application

    NASA Astrophysics Data System (ADS)

    Jablonski, Paul D.; Cowen, Christopher J.; Sears, John S.

    Alloy 441 stainless steel (UNS S 44100) is being considered for application as an SOFC interconnect material. There are several advantages to the selection of this alloy over other iron-based or nickel-based alloys: first and foremost alloy 441ss is a production alloy which is both low in cost and readily available. Second, the coefficient of thermal expansion (CTE) more closely matches the CTE of the adjoining ceramic components of the fuel cell. Third, this alloy forms the Laves phase at typical SOFC operating temperatures of 600-800 °C. It is thought that the Laves phase preferentially consumes the Si present in the alloy microstructure. As a result it has been postulated that the long-term area specific resistance (ASR) performance degradation often seen with other ferritic stainless steels, which is associated with the formation of electrically resistive Si-rich oxide subscales, may be avoidable with alloy 441ss. In this paper we explore the physical metallurgy of alloy 441, combining computational thermodynamics with experimental verification, and discuss the results with regards to Laves phase formation under SOFC operating conditions. We show that the incorporation of the Laves phase into the microstructure cannot in itself remove sufficient Si from the ferritic matrix in order to completely avoid the formation of Si-rich oxide subscales. However, the thickness, morphology, and continuity of the Si-rich subscale that forms in this alloy is modified in comparison to non-Laves forming ferritic stainless steel alloys and therefore may not be as detrimental to long-term SOFC performance.

  10. Exploration of alloy 441 chemistry for solid oxide fuel cell interconnect application

    SciTech Connect

    Jablonski, Paul D.; Cowen, Christopher J.; Sears, John S.

    2010-02-01

    Alloy 441 stainless steel (UNS S 44100) is being considered for application as an SOFC interconnect material. There are several advantages to the selection of this alloy over other iron-based or nickel-based alloys: first and foremost alloy 441ss is a production alloy which is both low in cost and readily available. Second, the coefficient of thermal expansion (CTE) more closely matches the CTE of the adjoining ceramic components of the fuel cell. Third, this alloy forms the Laves phase at typical SOFC operating temperatures of 600–800 °C. It is thought that the Laves phase preferentially consumes the Si present in the alloy microstructure. As a result it has been postulated that the long-term area specific resistance (ASR) performance degradation often seen with other ferritic stainless steels, which is associated with the formation of electrically resistive Si-rich oxide subscales, may be avoidable with alloy 441ss. In this paper we explore the physical metallurgy of alloy 441, combining computational thermodynamics with experimental verification, and discuss the results with regards to Laves phase formation under SOFC operating conditions. We show that the incorporation of the Laves phase into the microstructure cannot in itself remove sufficient Si from the ferritic matrix in order to completely avoid the formation of Si-rich oxide subscales. Finally, however, the thickness, morphology, and continuity of the Si-rich subscale that forms in this alloy is modified in comparison to non-Laves forming ferritic stainless steel alloys and therefore may not be as detrimental to long-term SOFC performance.

  11. Exploration of alloy 441 chemistry for solid oxide fuel cell interconnect application

    SciTech Connect

    Paul D. Jablonski; Christopher J. Cowen; John S. Sears

    2010-02-01

    Alloy 441 stainless steel (UNS S 44100) is being considered for application as an SOFC interconnect material. There are several advantages to the selection of this alloy over other iron-based or nickel-based alloys: first and foremost alloy 441ss is a production alloy which is both low in cost and readily available. Second, the coefficient of thermal expansion (CTE) more closely matches the CTE of the adjoining ceramic components of the fuel cell. Third, this alloy forms the Laves phase at typical SOFC operating temperatures of 600–800 °C. It is thought that the Laves phase preferentially consumes the Si present in the alloy microstructure. As a result it has been postulated that the long-term area specific resistance (ASR) performance degradation often seen with other ferritic stainless steels, which is associated with the formation of electrically resistive Si-rich oxide subscales, may be avoidable with alloy 441ss. In this paper we explore the physical metallurgy of alloy 441, combining computational thermodynamics with experimental verification, and discuss the results with regards to Laves phase formation under SOFC operating conditions. We show that the incorporation of the Laves phase into the microstructure cannot in itself remove sufficient Si from the ferritic matrix in order to completely avoid the formation of Si-rich oxide subscales. However, the thickness, morphology, and continuity of the Si-rich subscale that forms in this alloy is modified in comparison to non-Laves forming ferritic stainless steel alloys and therefore may not be as detrimental to long-term SOFC performance.

  12. Solid oxide fuel cell/gas turbine trigeneration system for marine applications

    NASA Astrophysics Data System (ADS)

    Tse, Lawrence Kar Chung; Wilkins, Steven; McGlashan, Niall; Urban, Bernhard; Martinez-Botas, Ricardo

    2011-03-01

    Shipping contributes 4.5% to global CO2 emissions and is not covered by the Kyoto Agreement. One method of reducing CO2 emissions on land is combined cooling heating and power (CCHP) or trigeneration, with typical combined thermal efficiencies of over 80%. Large luxury yachts are seen as an ideal entry point to the off-shore market for this developing technology considering its current high cost. This paper investigates the feasibility of combining a SOFC-GT system and an absorption heat pump (AHP) in a trigeneration system to drive the heating ventilation and air conditioning (HVAC) and electrical base-load systems. A thermodynamic model is used to simulate the system, with various configurations and cooling loads. Measurement of actual yacht performance data forms the basis of this system simulation. It is found that for the optimum configuration using a double effect absorption chiller in Ship 1, the net electric power increases by 47% relative to the electrical power available for a conventional SOFC-GT-HVAC system. This is due to more air cooled to a lower temperature by absorption cooling; hence less electrical cooling by the conventional HVAC unit is required. The overall efficiency is 12.1% for the conventional system, 34.9% for the system with BROAD single effect absorption chiller, 43.2% for the system with double effect absorption chiller. This shows that the overall efficiency of a trigeneration system is far higher when waste heat recovery happens. The desiccant wheel hardly reduces moisture from the outdoor air due to a relative low mass flow rate of fuel cell exhaust available to dehumidify a very large mass flow rate of HVAC air, Hence, desiccant wheel is not recommended for this application.

  13. Laser induced densification of cerium gadolinium oxide: Application to single-chamber solid oxide fuel cells

    NASA Astrophysics Data System (ADS)

    Mariño, Mariana; Rieu, Mathilde; Viricelle, Jean-Paul; Garrelie, Florence

    2016-06-01

    In single-chamber solid oxide fuel cells (SC-SOFC), anode and cathode are placed in a gas chamber where they are exposed to a fuel/air mixture. Similarly to conventional dual-chamber SOFC, the anode and the cathode are separated by an electrolyte. However, as in the SC-SOFC configuration the electrolyte does not play tightness role between compartments, this one can be a porous layer. Nevertheless, it is necessary to have a diffusion barrier to prevent the transportation of hydrogen produced locally at the anode to the cathode that reduces fuel cell performances. This study aims to obtain directly a diffusion barrier through the surface densification of the electrolyte Ce0.9Gd0.1O1.95 (CGO) by a laser treatment. KrF excimer laser and Yb fiber laser irradiations were used at different fluences and number of pulses to modify the density of the electrolyte coating. Microstructural characterizations confirmed the modifications on the surface of the electrolyte for appropriate experimental conditions showing either grain growth or densified but cracked surfaces. Gas permeation and electrical conductivities of the modified electrolyte were evaluated. Finally SC-SOFC performances were improved for the cells presenting grain growth at the electrolyte surface.

  14. Hydrogen Storage in Diamond Powder Utilizing Plasma NaF Surface Treatment for Fuel Cell Applications

    SciTech Connect

    Leal, David A.; Leal-Quiros, E.; Velez, Angel; Prelas, Mark A.; Gosh, Tushar

    2006-12-04

    Hydrogen Fuel Cells offer the vital solution to the world's socio-political dependence on oil. Due to existing difficulty in safe and efficient hydrogen storage for fuel cells, storing the hydrogen in hydrocarbon compounds such as artificial diamond is a realistic solution. By treating the surface of the diamond powder with a Sodium Fluoride plasma exposure, the surface of the diamond is cleaned of unwanted molecules. Due to fluorine's electro negativity, the diamond powder is activated and ready for hydrogen absorption. These diamond powder pellets are then placed on a graphite platform that is heated by conduction in a high voltage circuit made of tungsten wire. Then, the injection of hydrogen gas into chamber allows the storage of the Hydrogen on the surface of the diamond powder. By neutron bombardment in the nuclear reactor, or Prompt Gamma Neutron Activation Analysis, the samples are examined for parts per million amounts of hydrogen in the sample. Sodium Fluoride surface treatment allows for higher mass percentage of stored hydrogen in a reliable, resistant structure, such as diamond for fuel cells and permanently alters the diamonds terminal bonds for re-use in the effective storage of hydrogen. The highest stored amount utilizing the NaF plasma surface treatment was 22229 parts per million of hydrogen in the diamond powder which amounts to 2.2229% mass increase.

  15. Fuel cell system combustor

    DOEpatents

    Pettit, William Henry

    2001-01-01

    A fuel cell system including a fuel reformer heated by a catalytic combustor fired by anode and cathode effluents. The combustor includes a turbulator section at its input end for intimately mixing the anode and cathode effluents before they contact the combustors primary catalyst bed. The turbulator comprises at least one porous bed of mixing media that provides a tortuous path therethrough for creating turbulent flow and intimate mixing of the anode and cathode effluents therein.

  16. Fuel cell system configurations

    DOEpatents

    Kothmann, Richard E.; Cyphers, Joseph A.

    1981-01-01

    Fuel cell stack configurations having elongated polygonal cross-sectional shapes and gaskets at the peripheral faces to which flow manifolds are sealingly affixed. Process channels convey a fuel and an oxidant through longer channels, and a cooling fluid is conveyed through relatively shorter cooling passages. The polygonal structure preferably includes at least two right angles, and the faces of the stack are arranged in opposite parallel pairs.

  17. The application of Dow Chemical's perfluorinated membranes in proton-exchange membrane fuel cells

    NASA Technical Reports Server (NTRS)

    Eisman, G. A.

    1989-01-01

    Dow Chemical's research activities in fuel cell devices revolves around the development and subsequent investigation of the perfluorinated inomeric membrane separator useful in proton-exchange membrane systems. Work is currently focusing on studying the effects of equivalent weight, thickness, water of hydration, pretreatment procedures, as well as the degree of water management required for a given membrane separator in the cell. The presentation will include details of certain aspects of the above as well as some of the requirements for high and low power generation.

  18. Components and materials issues in polymer electrolyte fuel cells for transportation applications

    SciTech Connect

    Derouin, C.R.; Springer, T.E.; Uribe, F.A.; Valerio, J.A.; Wilson, M.S.; Zawodzinski, T.A.; Gottesfeld, S.

    1992-01-01

    Recent research work on the polymer electrolyte fuel cell (PEFC) is described. This research work addresses the goal of bringing the PEFC technology to the performance and the cost levels required for its wide spread use in transportation. The main topics are (a) a new approach to the fabrication of Pt/C catalyst layers of high performance, employing loadings as low as 0.1 mgPt/cm{sup 2}; (b) measurements and modeling of membrane, cathode catalyst and cathode backing contributions to cell loses in the PEFC; and (c) carbon monoxide poisoning of anode electrocatalysts in the PEFC -- the problem and possible solutions. 13 refs.

  19. Fuel-cell-powered golf cart

    SciTech Connect

    Bobbett, R.E.; McCormick, J.B.; Lynn, D.K.; Kerwin, W.J.; Derouin, C.R.; Salazar, P.H.

    1980-01-01

    The implementation of a battery/fuel-cell-powered golf cart test bed designed to verify computer simulations and to gain operational experience with a fuel cell in a vehicular environment is described. A technically untrained driver can easily operate the golf cart because the motor and fuel cell controllers automatically sense and execute the appropriate on/off sequencing. A voltage imbalance circuit and a throttle compress circuit were developed that are directly applicable to electric vehicles in general.

  20. Application of Multi-port Bidirectional DC-DC Converter to Fuel Cell Vehicle Driving in JC08 Mode

    NASA Astrophysics Data System (ADS)

    Tanaka, Katsunori; Katayama, Noboru; Kogoshi, Sumio; Fukada, Takafumi; Ogawa, Makoto

    A fuel cell-EDLC hybrid power system with a multi-port bidirectional DC-DC converter has been recently proposed for extending lifetime of a fuel cell due to smoothing the output current of the fuel cell. This paper studies the performance of the hybrid power system when a fuel cell vehicle drives in the JC08 mode using a simulation model. The simulation results indicate that even if the load current fluctuates, the output current of the fuel cell could be maintained at almost constant values with an assist from the EDLC although small spikes are observed.

  1. PEM fuel cell durability studies

    SciTech Connect

    Borup, Rodney L; Davey, John R; Ofstad, Axel B; Xu, Hui

    2008-01-01

    The durability of polymer electrolyte membrane (PEM) fuel cells is a major barrier to the commercialization for stationary and transportation power applications. For transportation applications, the durability target for fuel cell power systems is a 5,000 hour lifespan and able to function over a range of vehicle operating conditions (-40{sup o} to +40{sup o}C). However, durability is difficult to quantify and improve because of the quantity and duration of testing required, and also because the fuel cell stack contains many components, for which the degradation mechanisms, component interactions and effects of operating conditions are not fully understood. These requirements have led to the development of accelerated testing protocols for PEM fuel cells. The need for accelerated testing methodology is exemplified by the times required for standard testing to reach their required targets: automotive 5,000 hrs = {approx} 7 months; stationary systems 40,000 hrs = {approx} 4.6 years. As new materials continue to be developed, the need for relevant accelerated testing increases. In this investigation, we examine the durability of various cell components, examine the effect of transportation operating conditions (potential cycling, variable RH, shut-down/start-up, freeze/thaw) and evaluate durability by accelerated durability protocols. PEM fuel cell durability testing is performed on single cells, with tests being conducted with steady-state conditions and with dynamic conditions using power cycling to simulate a vehicle drive cycle. Component and single-cell characterization during and after testing was conducted to identify changes in material properties and related failure mechanisms. Accelerated-testing experiments were applied to further examine material degradation.

  2. Internal reforming fuel cell assembly with simplified fuel feed

    DOEpatents

    Farooque, Mohammad; Novacco, Lawrence J.; Allen, Jeffrey P.

    2001-01-01

    A fuel cell assembly in which fuel cells adapted to internally reform fuel and fuel reformers for reforming fuel are arranged in a fuel cell stack. The fuel inlet ports of the fuel cells and the fuel inlet ports and reformed fuel outlet ports of the fuel reformers are arranged on one face of the fuel cell stack. A manifold sealing encloses this face of the stack and a reformer fuel delivery system is arranged entirely within the region between the manifold and the one face of the stack. The fuel reformer has a foil wrapping and a cover member forming with the foil wrapping an enclosed structure.

  3. Adsorption behavior of low concentration carbon monoxide on polymer electrolyte fuel cell anodes for automotive applications

    NASA Astrophysics Data System (ADS)

    Matsuda, Yoshiyuki; Shimizu, Takahiro; Mitsushima, Shigenori

    2016-06-01

    The adsorption behavior of CO on the anode around the concentration of 0.2 ppm allowed by ISO 14687-2 is investigated in polymer electrolyte fuel cells (PEFCs). CO and CO2 concentrations in the anode exhaust are measured during the operation of a JARI standard single cell at 60 °C cell temperature and 1000 mA cm-2 current density. CO coverage is estimated from the gas analysis and CO stripping voltammetry. The cell voltage decrease as a result of 0.2 ppm CO is 29 mV and the CO coverage is 0.6 at the steady state with 0.11 mg cm-2 of anode platinum loading. The CO coverage as a function of CO concentration approximately follows a Temkin-type isotherm. Oxygen permeated to the anode through a membrane is also measured during fuel cell operation. The exhaust velocity of oxygen from the anode was shown to be much higher than the CO supply velocity. Permeated oxygen should play an important role in CO oxidation under low CO concentration conditions.

  4. Development of PEM fuel cell technology at international fuel cells

    SciTech Connect

    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.

  5. Direct-hydrogen-fueled proton-exchange-membrane (PEM) fuel cell system for transportation applications. Quarterly technical progress report No. 4, April 1, 1995--June 30, 1995

    SciTech Connect

    Oei, D.

    1995-08-03

    This is the fourth Technical Progress Report for DOE Contract No. DE-AC02-94CE50389 awarded to Ford Motor Company on July 1, 1994. The overall objective of this contract is to advance the Proton-Exchange-Membrane (PEM) fuel cell technology for automotive applications. Specifically, the objectives resulting from this contract are to: (1) Develop and demonstrate on a laboratory propulsion system within 2-1/2 years a fully functional PEM Fuel Cell Power System (including fuel cell peripherals, peak power augmentation and controls). This propulsion system will achieve, or will be shown to have the growth potential to achieve, the weights, volumes, and production costs which are competitive with those same attributes of equivalently performing internal combustion engine propulsion systems; (2) Select and demonstrate a baseline onboard hydrogen storage method with acceptable weight, volume, cost, and safety features and analyze future alternatives; and (3) Analyze the hydrogen infrastructure components to ensure that hydrogen can be safely supplied to vehicles at geographically widespread convenient sites and at prices which are less than current gasoline prices per vehicle-mile; (4) Identify any future R&D needs for a fully integrated vehicle and for achieving the system cost and performance goals.

  6. Fuel quality issues in stationary fuel cell systems.

    SciTech Connect

    Papadias, D.; Ahmed, S.; Kumar, R.

    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

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

    NASA Astrophysics Data System (ADS)

    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.

  8. The TMI Regenerative Solid Oxide Fuel Cell

    NASA Technical Reports Server (NTRS)

    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.

  9. Fuel cell technology program

    NASA Technical Reports Server (NTRS)

    1972-01-01

    A program to advance the technology for a cost-effective hydrogen/oxygen fuel cell system for future manned spacecraft is discussed. The evaluation of base line design concepts and the development of product improvements in the areas of life, power, specific weight and volume, versatility of operation, field maintenance and thermal control were conducted from the material and component level through the fabrication and test of an engineering model of the fuel cell system. The program was to be accomplished in a 13 month period.

  10. Modeling a 5 kWe planar solid oxide fuel cell based system operating on JP-8 fuel and a comparison with tubular cell based system for auxiliary and mobile power applications

    NASA Astrophysics Data System (ADS)

    Tanim, Tanvir; Bayless, David J.; Trembly, Jason P.

    2014-01-01

    A steady state planar solid oxide fuel cell (P-SOFC) based system operating on desulfurized JP-8 fuel was modeled using Aspen Plus simulation software for auxiliary and mobile power applications. An onboard autothermal reformer (ATR) employed to reform the desulfurized JP-8 fuel was coupled with the P-SOFC stack to provide for H2 and CO as fuel, minimizing the cost and complexity associated with hydrogen storage. Characterization of the ATR reformer was conducted by varying the steam to carbon ratio (H2O/C) from 0.1 to 1.0 at different ATR operating temperatures (700-800 °C) while maintaining the P-SOFC stack temperature at 850 °C. A fraction of the anode recycle was used as the steam and heat source for autothermal reforming of the JP-8 fuel, intending to make the system lighter and compact for mobile applications. System modeling revealed a maximum net AC efficiency of 37.1% at 700 °C and 29.2% at 800 °C ATR operating temperatures, respectively. Parametric analyses with respect to fuel utilization factor (Uf) and current density (j) were conducted to determine optimum operating conditions. Finally, the P-SOFC based system was compared with a previously published [1] tubular solid oxide fuel cell based (T-SOFC) system to identify the relative advantages over one another.

  11. Compact fuel cell

    DOEpatents

    Jacobson, Craig; DeJonghe, Lutgard C.; Lu, Chun

    2010-10-19

    A novel electrochemical cell which may be a solid oxide fuel cell (SOFC) is disclosed where the cathodes (144, 140) may be exposed to the air and open to the ambient atmosphere without further housing. Current collector (145) extends through a first cathode on one side of a unit and over the unit through the cathode on the other side of the unit and is in electrical contact via lead (146) with housing unit (122 and 124). Electrical insulator (170) prevents electrical contact between two units. Fuel inlet manifold (134) allows fuel to communicate with internal space (138) between the anodes (154 and 156). Electrically insulating members (164 and 166) prevent the current collector from being in electrical contact with the anode.

  12. Fuel Cell Stations Automate Processes, Catalyst Testing

    NASA Technical Reports Server (NTRS)

    2010-01-01

    Glenn Research Center looks for ways to improve fuel cells, which are an important source of power for space missions, as well as the equipment used to test fuel cells. With Small Business Innovation Research (SBIR) awards from Glenn, Lynntech Inc., of College Station, Texas, addressed a major limitation of fuel cell testing equipment. Five years later, the company obtained a patent and provided the equipment to the commercial world. Now offered through TesSol Inc., of Battle Ground, Washington, the technology is used for fuel cell work, catalyst testing, sensor testing, gas blending, and other applications. It can be found at universities, national laboratories, and businesses around the world.

  13. Highly stable precious metal-free cathode catalyst for fuel cell application

    NASA Astrophysics Data System (ADS)

    Serov, Alexey; Workman, Michael J.; Artyushkova, Kateryna; Atanassov, Plamen; McCool, Geoffrey; McKinney, Sam; Romero, Henry; Halevi, Barr; Stephenson, Thomas

    2016-09-01

    A platinum group metal-free (PGM-free) oxygen reduction reaction (ORR) catalyst engineered for stability has been synthesized using the sacrificial support method (SSM). This catalyst was comprehensively characterized by physiochemical analyses and tested for performance and durability in fuel cell membrane electrode assemblies (MEAs). This catalyst, belonging to the family of Fe-N-C materials, is easily scalable and can be manufactured in batches up to 200 g. The fuel cell durability tests were performed in a single cell configuration at realistic operating conditions of 0.65 V, 1.25 atmgauge air, and 90% RH for 100 h. In-depth characterization of surface chemistry and morphology of the catalyst layer before and after durability tests were performed. The failure modes of the PGM-free electrodes were derived from structure-to-property correlations. It is suggested that under constant voltage operation, the performance loss results from degradation of the electrode pore structure, while under carbon corrosion accelerated test protocols the failure mode is catalyst corrosion.

  14. European Fuel Cells R&D Review

    NASA Astrophysics Data System (ADS)

    Michael, P. D.; Maguire, J.

    1994-09-01

    A review is presented on the status of fuel cell development in Europe, addressing the research, development, and demonstration (RD&D) and commercialization activities being undertaken, identifying key European organizations active in development and commercialization of fuel cells, and detailing their future plans. This document describes the RD&D activities in Europe on alkaline, phosphoric acid, polymer electrolyte, direct methanol, solid oxide, and molten carbonate fuel cell types. It describes the European Commission's activities, its role in the European development of fuel cells, and its interaction with the national programs. It then presents a country-by-country breakdown. For each country, an overview is given, presented by fuel cell type. Scandinavian countries are covered in less detail. American organizations active in Europe, either in supplying fuel cell components, or in collaboration, are identified. Applications include transportation and cogeneration.

  15. Investigation of low temperature solid oxide fuel cells for air-independent UUV applications

    NASA Astrophysics Data System (ADS)

    Moton, Jennie Mariko

    Unmanned underwater vehicles (UUVs) will benefit greatly from high energy density (> 500 Wh/L) power systems utilizing high-energy-density fuels and air-independent oxidizers. Current battery-based systems have limited energy densities (< 400 Wh/L), which motivate development of alternative power systems such as solid oxide fuel cells (SOFCs). SOFC-based power systems have the potential to achieve the required UUV energy densities, and the current study explores how SOFCs based on gadolinia-doped ceria (GDC) electrolytes with operating temperatures of 650°C and lower may operate in the unique environments of a promising UUV power plant. The plant would contain a H 2O2 decomposition reactor to supply humidified O2 to the SOFC cathode and exothermic aluminum/H2O combustor to provide heated humidified H2 fuel to the anode. To characterize low-temperature SOFC performance with these unique O2 and H2 source, SOFC button cells based on nickel/GDC (Gd0.1Ce0.9O 1.95) anodes, GDC electrolytes, and lanthanum strontium cobalt ferrite (La0.6Sr0.4Co0.2Fe0.8O3-δ or LSCF)/GDC cathodes were fabricated and tested for performance and stability with humidity on both the anode and the cathode. Cells were also tested with various reactant concentrations of H2 and O2 to simulate gas depletion down the channel of an SOFC stack. Results showed that anode performance depended primarily on fuel concentration and less on the concentration of the associated increase in product H2O. O 2 depletion with humidified cathode flows also caused significant loss in cell current density at a given voltage. With the humidified flows in either the anode or cathode, stability tests of the button cells at 650 °C showed stable voltage is maintained at low operating current (0.17 A/cm2) at up to 50 % by mole H2O, but at higher current densities (0.34 A/cm2), irreversible voltage degradation occurred at rates of 0.8-3.7 mV/hour depending on exposure time. From these button cell results, estimated average

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

    NASA Astrophysics Data System (ADS)

    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.

  17. Air Breathing Direct Methanol Fuel Cell

    DOEpatents

    Ren; Xiaoming

    2003-07-22

    A method for activating a membrane electrode assembly for a direct methanol fuel cell is disclosed. The method comprises operating the fuel cell with humidified hydrogen as the fuel followed by running the fuel cell with methanol as the fuel.

  18. Fuel cell generator

    DOEpatents

    Makiel, Joseph M.

    1985-01-01

    A high temperature solid electrolyte fuel cell generator comprising a housing means defining a plurality of chambers including a generator chamber and a combustion products chamber, a porous barrier separating the generator and combustion product chambers, a plurality of elongated annular fuel cells each having a closed end and an open end with the open ends disposed within the combustion product chamber, the cells extending from the open end through the porous barrier and into the generator chamber, a conduit for each cell, each conduit extending into a portion of each cell disposed within the generator chamber, each conduit having means for discharging a first gaseous reactant within each fuel cell, exhaust means for exhausting the combustion product chamber, manifolding means for supplying the first gaseous reactant to the conduits with the manifolding means disposed within the combustion product chamber between the porous barrier and the exhaust means and the manifolding means further comprising support and bypass means for providing support of the manifolding means within the housing while allowing combustion products from the first and a second gaseous reactant to flow past the manifolding means to the exhaust means, and means for flowing the second gaseous reactant into the generator chamber.

  19. Utilization of Pt/Ru catalysts in MEA for fuel cell application by breathing process of proton exchange membrane

    NASA Astrophysics Data System (ADS)

    Yu, Kyung-Chul; Kim, Woo-Jae; Chung, Chan-Hwa

    Small direct-methanol fuel cells (DMFCs) have recently been highlighted as possible power sources for applications ranging from cellular phones and wireless digital devices to autonomous sensors and micro-electro mechanical devices. One of the key issues in commercializing miniaturized DMFCs for portable applications is to improve the electrochemical performance of the cells with a small quantity of catalysts. Up to now, the spraying or brush method has been used to fabricate a catalyst layer, which uses a slurry of nano-sized Pt or Pt/Ru catalysts. However, these methods produce a poor electrochemical interface that reduces the catalytic activity and the reproducibility of their performance tests. In this study, a unique process known as a "breathing process" was used to fabricate a catalytic electrode layer in a membrane-electrode-assembly (MEA) of DMFCs. The Pt/Ru nano-particles were loaded directly onto a proton exchange membrane using this breathing process. This process consisted of the following three steps: (1) the electrolyte membrane was fully swollen in water; (2) the swollen membrane was placed into an aprotic solvent, which induced the shrinkage of the membrane by driving the water out ("breathing out"); (3) the shrunken membrane was placed in an aqueous solution containing a suspension of Pt/Ru nano-particles. This induces the swelling of the membrane, and the suspended Pt/Ru nano-particles penetrate the membrane during this process ("breathing in"). It is possible to control the amount of catalysts loaded in the MEA by controlling the number of the cycles of such breathing processes. Compared with the fuel cell adopting the MEA fabricated by a conventional spraying method with the same amount of catalysts, the performance of this novel fuel cell was enhanced by approximately 4.5 mW cm -2 in case of the passive-type fuel cell and by 9.0 mW cm -2 in case of the active-type. This paper details the optimized process conditions along with other advanced

  20. Organic fuel cells and fuel cell conducting sheets

    DOEpatents

    Masel, Richard I.; Ha, Su; Adams, Brian

    2007-10-16

    A passive direct organic fuel cell includes an organic fuel solution and is operative to produce at least 15 mW/cm.sup.2 when operating at room temperature. In additional aspects of the invention, fuel cells can include a gas remover configured to promote circulation of an organic fuel solution when gas passes through the solution, a modified carbon cloth, one or more sealants, and a replaceable fuel cartridge.

  1. Fuel economy and range estimates for fuel cell powered automobiles

    SciTech Connect

    Steinbugler, M.; Ogden, J.

    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.

  2. Fuel cell technology program

    NASA Technical Reports Server (NTRS)

    1973-01-01

    A fuel cell technology program was established to advance the state-of-the-art of hydrogen-oxygen fuel cells using low temperature, potassium hydroxide electrolyte technology as the base. Program tasks are described consisting of baseline cell design and stack testing, hydrogen pump design and testing, and DM-2 powerplant testing and technology extension efforts. A baseline cell configuration capable of a minimum of 2000 hours of life was defined. A 6-cell prototype stack, incorporating most of the scheme cell features, was tested for a total of 10,497 hours. A 6-cell stack incorporating all of the design features was tested. The DM-2 powerplant with a 34 cell stack, an accessory section packaged in the basic configuration anticipated for the space shuttle powerplant and a powerplant control unit, was defined, assembled, and tested. Cells were used in the stack and a drag-type hydrogen pump was installed in the accessory section. A test program was established, in conjunction with NASA/JSC, based on space shuttle orbiter mission. A 2000-hour minimum endurance test and a 5000-hour goal were set and the test started on August 8, 1972. The 2000-hour milestone was completed on November 3, 1972. On 13 March 1973, at the end of the thirty-first simulated seven-day mission and 5072 load hours, the test was concluded, all goals having been met. At this time, the DM-2 was in excellent condition and capable of additional endurance.

  3. Fuel Cell Technical Team Roadmap

    SciTech Connect

    2013-06-01

    The Fuel Cell Technical Team promotes the development of a fuel cell power system for an automotive powertrain that meets the U.S. DRIVE Partnership (United States Driving Research and Innovation for Vehicle efficiency and Energy sustainability) goals.

  4. Mass transfer in fuel cells

    NASA Technical Reports Server (NTRS)

    Walker, R. D., Jr.

    1973-01-01

    Developments in the following areas are reported: surface area and pore size distribution in electrolyte matrices, electron microscopy of electrolyte matrices, surface tension of KOH solutions, water transport in fuel cells, and effectiveness factors for fuel cell components.

  5. Proton exchange membrane fuel cells for space and electric vehicle applications: From basic research to technology development

    NASA Technical Reports Server (NTRS)

    Srinivasan, Supramaniam; Mukerjee, Sanjeev; Parthasarathy, A.; CesarFerreira, A.; Wakizoe, Masanobu; Rho, Yong Woo; Kim, Junbom; Mosdale, Renaut A.; Paetzold, Ronald F.; Lee, James

    1994-01-01

    The proton exchange membrane fuel cell (PEMFC) is one of the most promising electrochemical power sources for space and electric vehicle applications. The wide spectrum of R&D activities on PEMFC's, carried out in our Center from 1988 to date, is as follows (1) Electrode Kinetic and Electrocatalysis of Oxygen Reduction; (2) Optimization of Structures of Electrodes and of Membrane and Electrode Assemblies; (3) Selection and Evaluation of Advanced Proton Conducting Membranes and of Operating Conditions to Attain High Energy Efficiency; (4) Modeling Analysis of Fuel Cell Performance and of Thermal and Water Management; and (5) Engineering Design and Development of Multicell Stacks. The accomplishments on these tasks may be summarized as follows: (1) A microelectrode technique was developed to determine the electrode kinetic parameters for the fuel cell reactions and mass transport parameters for the H2 and O2 reactants in the proton conducting membrane. (2) High energy efficiencies and high power densities were demonstrated in PEMFCs with low platinum loading electrodes (0.4 mg/cm(exp 2) or less), advanced membranes and optimized structures of membrane and electrode assemblies, as well as operating conditions. (3) The modeling analyses revealed methods to minimize mass transport limitations, particularly with air as the cathodic reactant; and for efficient thermal and water management. (4) Work is in progress to develop multi-kilowatt stacks with the electrodes containing low platinum loadings.

  6. Preparation and characterization of mono-sheet bipolar membranes by pre-irradiation grafting method for fuel cell applications

    NASA Astrophysics Data System (ADS)

    Guan, Yingjie; Fang, Jun; Fu, Tao; Zhou, Huili; Wang, Xin; Deng, Zixiang; Zhao, Jinbao

    2016-09-01

    A new method for the preparation of the mono-sheet bipolar membrane applied to fuel cells was developed based on the pre-irradiation grafting technology. A series of bipolar membranes were successfully prepared by simultaneously grafting of styrene onto one side of the poly(ethylene-co-tetrafluoroethylene) base film and 1-vinylimidazole onto the opposite side, followed by the sulfonation and alkylation, respectively. The chemical structures and microstructures of the prepared membranes were investigated by ATR-FTIR and SEM-EDS. The TGA measurements demonstrated the prepared bipolar membranes have reasonable thermal stability. The ion exchange capacity, water uptake and ionic conductivity of the membranes were also characterized. The H2/O2 single fuel cells using these membranes were evaluated and revealed a maximum power density of 107 mW cm-2 at 35 °C with unhumidified hydrogen and oxygen. The preliminary performances suggested the great prospect of these membranes in application of bipolar membrane fuel cells.

  7. Synthesis and performance of novel anion exchange membranes based on imidazolium ionic liquids for alkaline fuel cell applications

    NASA Astrophysics Data System (ADS)

    Fang, Jun; Lyu, Ming; Wang, Xin; Wu, Yongbin; Zhao, Jinbao

    2015-06-01

    Novel anion exchange membranes (AEMs) based on two types of imidazolium ionic liquids, 1-vinyl-3-methylimidazolium iodide [VMI]I and 1-vinyl-3-butylimidazolium bromide [VBI]Br, have been synthesized by copolymerization. The obtained membranes are characterized in terms of water uptake, ion exchange capacity (IEC), ionic conductivity as well as thermal and chemical stability. The conductivity reaches 0.0226 Scm-1 at 30 °C. All the membranes show excellent thermostability. The membranes are stable in 10 mol L-1 NaOH solution at 60 °C for 120 h without obvious changes in ion conductivity. Fuel cell performance using the resulting membrane has been investigated. The open circuit voltage (OCV) of the H2/O2 fuel cell is 1.07 V. A peek power density of 116 mW cm-2 is obtained at a current density of 230 mA cm-2 at 60 °C. The results demonstrate the brilliant prospect of the developed membranes for alkaline fuel cell applications.

  8. Synthesis of transport layers with controlled anisotropy and application thereof to study proton exchange membrane fuel cell performance

    NASA Astrophysics Data System (ADS)

    Todd, Devin; Mérida, Walter

    2016-04-01

    We report on a novel method for the synthesis of fibre-based proton exchange membrane (PEM) fuel cell porous transport layers (PTLs) with controllable fibre alignment. We also report the first application of such layers as diagnostics tools to probe the effect of within-plane PTL anisotropy upon PEM fuel cell performance. These structures are realized via adaptation of electrospinning technology. Electrospun layers with progressive anisotropy magnitude are produced and evaluated. This novel approach is distinguished from the state-of-the-art because an equivalent study using commercially available materials is impossible due to lack of structurally similar substrates with different anisotropies. The anisotropy is visualized via scanning electron microscopy, and quantified using electrical resistivity. The capacity is demonstrated to achieve fibre alignment, and the associated impact on transport properties. A framework is presented for assessing the in-situ performance, whereby transport layer orientation versus bipolar plate flow-field geometry is manipulated. While an effect upon the commercial baseline cannot be discerned, electrospun transport layers with greater anisotropy magnitude suggest greater sensitivity to orientation; where greater performance is obtained with fibres cross-aligned to flow-field channels. Our approach of electrospun transport enables deterministic structures by which fuel cell performance can be explained and optimized.

  9. Aluminum and aluminum alloys as sources of hydrogen for fuel cell applications

    NASA Astrophysics Data System (ADS)

    Soler, Lluís; Macanás, Jorge; Muñoz, Maria; Casado, Juan

    Production of hydrogen using aluminum and aluminum alloys with aqueous alkaline solutions is studied. This process is based on aluminum corrosion, consuming only water and aluminum which are cheaper raw materials than other compounds used for in situ hydrogen generation, such as chemical hydrides. In principle, this method does not consume alkali because the aluminate salts produced in the hydrogen generation undergo a decomposition reaction that regenerates the alkali. As a consequence, this process could be a feasible alternative for hydrogen production to supply fuel cells. Preliminary results showed that an increase of base concentration and working solution temperature produced an increase of hydrogen production rate using pure aluminum. Furthermore, an improvement of hydrogen production rates and yields was observed varying aluminum alloys composition and increasing their reactive surface, with interesting results for Al/Si and Al/Co alloys. The development of this idea could improve yields and reduce costs in power units based on fuel cells which use hydrides as raw material for hydrogen production.

  10. Diesel steam reforming with a nickel-alumina spinel catalyst for solid oxide fuel cell application

    NASA Astrophysics Data System (ADS)

    Fauteux-Lefebvre, Clémence; Abatzoglou, Nicolas; Braidy, Nadi; Achouri, Ines Esma

    Liquid hydrocarbons (LC) are considered as fuel cells feed and, more particularly, as solid oxide fuel cell feed. Cost-effective LC-reforming catalysts are critically needed for the successful commercialization of such technologies. An alternative to noble metal catalysts, proposed by the authors in a previous publication, has been proven efficient for diesel steam reforming (SR). Nickel, less expensive and more readily available than noble metals, was used in a form that prevents deactivation. The catalyst formulation is a Ni-alumina spinel (NiAl 2O 4) supported on alumina (Al 2O 3) and yttria-stabilized zirconia (YSZ). SR of commercial diesel was undertaken for more than 15 h at high gas hourly space velocities and steam-to-carbon ratios lower than 2. Constant diesel conversion and high hydrogen concentrations were obtained. Ni catalyst characterization revealed no detectable amounts of carbon on the spinel catalyst surface Ni. The effect of catalyst composition (Ni concentration and YSZ presence) was studied to understand and optimize the developed catalyst. Two phenomena were found to be influenced by relative catalyst composition: water-gas-shift vs reforming reaction extent, and concentration of light hydrocarbons in products.

  11. Sulfonated silica-based fuel cell electrode structures for low humidity applications

    NASA Astrophysics Data System (ADS)

    Eastcott, Jennie I.; Easton, E. Bradley

    2014-01-01

    Ceramic carbon electrodes (CCEs) are prospective candidates for use in proton exchange membrane fuel cells due to their high surface area, water retention properties, and durable nature. We have determined that incorporating small amounts of sulfonated silane in the CCE structure can lead to a profound enhancement of catalytic activity and proton conductivity. To evaluate the usefulness of a new catalyst layer for practical use, performance of the materials under various conditions must be considered. We have compared the properties of membrane electrode assemblies (MEA) prepared with CCE cathode catalyst layers to that of an MEA prepared with Nafion-based cathode catalyst layers. The MEAs were characterized via transmission electron microscopy, thermogravimetric analysis, infrared spectroscopy, and BET analysis. Fuel cell performance using different cathode gas relative humidity (RH) feed conditions was monitored using electrochemical impedance spectroscopy and polarization curves. Our CCE cathode materials maintained stable performance and had improved water management capabilities at low relative humidities, whereas Nafion-containing cathodes have performed poorly. The enhanced performance and tolerance to low RH is explained in terms of water retention within the CCE-based MEA.

  12. Hybrid Microgrid Model based on Solar Photovoltaics with Batteries and Fuel Cells system for intermittent applications

    NASA Astrophysics Data System (ADS)

    Patterson, Maxx

    Microgrids are a subset of the modern power structure; using distributed generation (DG) to supply power to communities rather than vast regions. The reduced scale mitigates loss allowing the power produced to do more with better control, giving greater security, reliability, and design flexibility. This paper explores the performance and cost viability of a hybrid grid-tied microgrid that utilizes Photovoltaic (PV), batteries, and fuel cell (FC) technology. The concept proposes that each community home is equipped with more PV than is required for normal operation. As the homes are part of a microgrid, excess or unused energy from one home is collected for use elsewhere within the microgrid footprint. The surplus power that would have been discarded becomes a community asset, and is used to run intermittent services. In this paper, the modeled community does not have parking adjacent to each home allowing for the installment of a privately owned slower Level 2 charger, making EV ownership option untenable. A solution is to provide a Level 3 DC Quick Charger (DCQC) as the intermittent service. The addition of batteries and Fuel Cells are meant to increase load leveling, reliability, and instill limited island capability.

  13. Engineering interface and surface of noble metal nanoparticle nanotubes toward enhanced catalytic activity for fuel cell applications.

    PubMed

    Cui, Chun-Hua; Yu, Shu-Hong

    2013-07-16

    In order for fuel cells to have commercial viability as alternative fuel sources, researchers need to develop highly active and robust fuel cell electrocatalysts. In recent years, the focus has been on the design and synthesis of novel catalytic materials with controlled interface and surface structures. Another goal is to uncover potential catalytic activity and selectivity, as well as understand their fundamental catalytic mechanisms. Scientists have achieved great progress in the experimental and theoretical investigation due to the urgent demand for broad commercialization of fuel cells in automotive applications. However, there are still three main problems: cost, performance, and stability. To meet these targets, the catalyst needs to have multisynergic functions. In addition, the composition and structure changes of the catalysts during the reactions still need to be explored. Activity in catalytic nanomaterials is generally controlled by the size, shape, composition, and interface and surface engineering. As such, one-dimensional nanostructures such as nanowires and nanotubes are of special interest. However, these structures tend to lose the nanoparticle morphology and inhibit the use of catalysts in both fuel cell anodes and cathodes. In 2003, Rubinstein and co-workers proposed the idea of nanoparticle nanotubes (NNs), which combine the geometry of nanotubes and the morphology of nanoparticles. This concept gives both the high surface-to-volume ratio and the size effect, which are both appealing in electrocatalyst design. In this Account, we describe our developments in the construction of highly active NNs with unique surface and heterogeneous interface structures. We try to clarify enhanced activity and stability in catalytic systems by taking into account the activity impact factors. We briefly introduce material structural effects on the electrocatalytic reactivity including metal oxide/metal and metal/metal interfaces, dealloyed pure Pt, and mixed Pt

  14. Engineering interface and surface of noble metal nanoparticle nanotubes toward enhanced catalytic activity for fuel cell applications.

    PubMed

    Cui, Chun-Hua; Yu, Shu-Hong

    2013-07-16

    In order for fuel cells to have commercial viability as alternative fuel sources, researchers need to develop highly active and robust fuel cell electrocatalysts. In recent years, the focus has been on the design and synthesis of novel catalytic materials with controlled interface and surface structures. Another goal is to uncover potential catalytic activity and selectivity, as well as understand their fundamental catalytic mechanisms. Scientists have achieved great progress in the experimental and theoretical investigation due to the urgent demand for broad commercialization of fuel cells in automotive applications. However, there are still three main problems: cost, performance, and stability. To meet these targets, the catalyst needs to have multisynergic functions. In addition, the composition and structure changes of the catalysts during the reactions still need to be explored. Activity in catalytic nanomaterials is generally controlled by the size, shape, composition, and interface and surface engineering. As such, one-dimensional nanostructures such as nanowires and nanotubes are of special interest. However, these structures tend to lose the nanoparticle morphology and inhibit the use of catalysts in both fuel cell anodes and cathodes. In 2003, Rubinstein and co-workers proposed the idea of nanoparticle nanotubes (NNs), which combine the geometry of nanotubes and the morphology of nanoparticles. This concept gives both the high surface-to-volume ratio and the size effect, which are both appealing in electrocatalyst design. In this Account, we describe our developments in the construction of highly active NNs with unique surface and heterogeneous interface structures. We try to clarify enhanced activity and stability in catalytic systems by taking into account the activity impact factors. We briefly introduce material structural effects on the electrocatalytic reactivity including metal oxide/metal and metal/metal interfaces, dealloyed pure Pt, and mixed Pt

  15. Fuel cell membrane humidification

    DOEpatents

    Wilson, Mahlon S.

    1999-01-01

    A polymer electrolyte membrane fuel cell assembly has an anode side and a cathode side separated by the membrane and generating electrical current by electrochemical reactions between a fuel gas and an oxidant. The anode side comprises a hydrophobic gas diffusion backing contacting one side of the membrane and having hydrophilic areas therein for providing liquid water directly to the one side of the membrane through the hydrophilic areas of the gas diffusion backing. In a preferred embodiment, the hydrophilic areas of the gas diffusion backing are formed by sewing a hydrophilic thread through the backing. Liquid water is distributed over the gas diffusion backing in distribution channels that are separate from the fuel distribution channels.

  16. Fuel cell sub-assembly

    DOEpatents

    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.

  17. Fuel Cell/Electrochemical Cell Voltage Monitor

    NASA Technical Reports Server (NTRS)

    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.

  18. An ultrathin self-humidifying membrane for PEM fuel cell application: fabrication, characterization, and experimental analysis.

    PubMed

    Zhu, Xiaobing; Zhang, Huamin; Zhang, Yu; Liang, Yongmin; Wang, Xiaoli; Yi, Baolian

    2006-07-27

    An ultrathin poly(tetrafluoroethylene) (PTFE)-reinforced multilayer self-humidifying composite membrane (20 microm, thick) is developed. The membrane is composed of Nafion-impregnated porous PTFE composite as the central layer, and SiO2 supported nanosized Pt particles (Pt-SiO2) imbedded into the Nafion as the two side layers. The proton exchange membrane (PEM) fuel cell employing the self-humidifying membrane (Pt-SiO2/NP) turns out a peak power density of 1.40 W cm(-2) and an open circuit voltage (OCV) of 1.032 V under dry H2/O2 condition. The excellent performance is attributed to the combined result of both the accelerated water back-diffusion in the thin membrane and the adsorbing/releasing water properties of the Pt-SiO2 catalyst in the side layers. Moreover, the inclusion of the hygroscopic Pt-SiO2 catalyst inside the membrane results in an enhanced anode self-humidification capability and also the decreased cathode polarization (accordingly an improved cell OCV). Several techniques, such as transmission electronic microscopy, scanning electronic microscopy, energy dispersive spectroscopy, thermal analysis and electrochemical impedance spectroscopy etc., are employed to characterize the Pt-SiO2/NP membrane. The results are discussed in comparison with the plain Nafion/PTFE membrane (NP). It is established that the reverse net water drag (from the cathode to the anode) across the Pt-SiO2/NP membrane reaches 0.16 H2O/H+. This implies a good hydration of the Pt-SiO2/NP membrane and thus ensures an excellent PEM fuel cell performance under self-humidification operation.

  19. Processing of LaCrO{sub 3} for solid oxide fuel cell applications

    SciTech Connect

    Huebner, W.; Anderson, H.U.

    1995-08-01

    The University of Missouri-Rolla is performing a 5 year research program with two primary objectives: (1) developing LaCrO{sub 3}-based interconnect powders which densify when in contact with anode and cathode materials for solid oxide fuel cells (SOFC), and (2) developing high performance cathodes, anodes and interfaces for use in planar SOFC`s. With regard to the processing and sintering of LaCrO{sub 3}, the specific objectives of this research program are to: (1) Develop a non-liquid phase sintered LaCrO{sub 3}-based material sinterable in air. (2) Improve and control the properties requisite of LaCrO{sub 3} utilizing a B-site acceptor dopant. (3) Optimize and control the processing conditions associated with LaCrO{sub 3}. (4) Incorporate materials developed in this program into planar cells and measure their performance. With regard to developing high performance materials for use in planar SOFC`s, the specific objectives of this research program over the last year have been to: (1) Fabricate single cells with controlled microstructures (i.e. grain size and porosity of electrodes) for operation at 1000{degrees}C. (2) Gain a better understanding of the mechanisms involved in improving cell performance via electrochemical and impedance techniques. (3) Develop processing {leftrightarrow}microstructure{leftrightarrow} property relations of electrodes and their corresponding interfacial reactions.

  20. Low-temperature plasma synthesis of carbon nanotubes and graphene based materials and their fuel cell applications.

    PubMed

    Wang, Qi; Wang, Xiangke; Chai, Zhifang; Hu, Wenping

    2013-12-01

    Carbon nanotubes (CNTs) and graphene, and materials based on these, are largely used in multidisciplinary fields. Many techniques have been put forward to synthesize them. Among all kinds of approaches, the low-temperature plasma approach is widely used due to its numerous advantages, such as highly distributed active species, reduced energy requirements, enhanced catalyst activation, shortened operation time and decreased environmental pollution. This tutorial review focuses on the recent development of plasma synthesis of CNTs and graphene based materials and their electrochemical application in fuel cells. PMID:23959435

  1. Fabrication and characterization of a fuel flexible micro-reformer fully integrated in silicon for micro-solid oxide fuel cell applications

    NASA Astrophysics Data System (ADS)

    Pla, D.; Salleras, M.; Garbayo, I.; Morata, A.; Sabaté, N.; Divins, N. J.; Llorca, J.; Tarancón, A.

    2015-05-01

    A novel design of a fuel-flexible micro-reactor for hydrogen generation from ethanol and methane is proposed in this work. The micro-reactor is fully fabricated with mainstream MEMS technology and consists of an array of more than 20000 through-silicon vertically aligned micro-channels per cm2 of 50 μm in diameter. Due to this unique configuration, the micro-reformer presents a total surface per projected area of 16 cm2/cm2 and per volume of 320 cm2/cm3. The active surface of the micro-reformer, i.e. the walls of the micro-channels, is homogenously coated with a thin film of Rh- Pd/CeO2 catalyst. Excellent steam reforming of ethanol and dry reforming of methane are presented with hydrogen production rates above 3 mL/min·cm2 and hydrogen selectivity of ca. 50% on a dry basis at operations conditions suitable for application in micro-solid oxide fuel cells (micro-SOFCs), i.e. 700-800ºC and fuel flows of 0.02 mLL/min for ethanol and 36 mLG/min for methane (corresponding to a system able to produce one electrical watt).

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

    DOEpatents

    Ruka, Roswell J.; Basel, Richard A.; Zhang, Gong

    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.

  3. A fiber optics system for monitoring utilization of ZnO adsorbent beds during desulfurization for logistic fuel cell applications

    NASA Astrophysics Data System (ADS)

    Sujan, Achintya; Yang, Hongyun; Dimick, Paul; Tatarchuk, Bruce J.

    2016-05-01

    An in-situ fiber optic based technique for direct measurement of capacity utilization of ZnO adsorbent beds by monitoring bed color changes during desulfurization for fuel cell systems is presented. Adsorbents composed of bulk metal oxides (ZnO) and supported metal oxides (ZnO/SiO2 and Cusbnd ZnO/SiO2) for H2S removal at 22 °C are examined. Adsorbent bed utilization at breakthrough is determined by the optical sensor as the maximum derivative of area under UV-vis spectrum from 250 to 800 nm observed as a function of service time. Since the response time of the sensor due to bed color change is close to bed breakthrough time, a series of probes along the bed predicts utilization of the portion of bed prior to H2S breakthrough. The efficacy of the optical sensor is evaluated as a function of inlet H2S concentration, H2S flow rate and desulfurization in presence of CO, CO2 and moisture in feed. A 6 mm optical probe is employed to measure utilization of a 3/16 inch ZnO extrudate bed for H2S removal. It is envisioned that with the application of the optical sensor, desulfurization can be carried out at high adsorbent utilization and low operational costs during on-board miniaturized fuel processing for logistic fuel cell power systems.

  4. The role of fuel cells in NASA's space power systems

    NASA Technical Reports Server (NTRS)

    Been, J. F.

    1979-01-01

    A history of the fuel cell technology is presented and compared with NASA's increasing space power requirements. The role of fuel cells is discussed in perspective with other energy storage systems applicable for space using such criteria as type of mission, weight, reliability, costs, etc. Potential applications of space fuel cells with projected technology advances were examined.

  5. New fuel cells system for portable application with low temperature cofired ceramic (LTCC) technology

    NASA Astrophysics Data System (ADS)

    Gao, Yong

    Miniature direct methanol fuel cells (DMFCs) are promising micro power sources for portable appliction. Low temperature cofired ceramic (LTCC), a competitive technology for current MEMS based fabrication, provides cost-effective mass manufacturing route for miniature DMFCs. Porous silver tape is adapted as electrodes to replace the traditional porous carbon electrodes due to its compatibility to LTCC processing and other electrochemical advantages. Electrochemical evaluation of silver under DMFCs operating conditions demonstrated that silver is a good electrode for DMFCs because of its reasonable corrosion resistance, low passivating current, and enhanced catalytic effect. Two catalyst loading methods (cofiring and postfiring) of the platinum and ruthenium catalysts are evaluated for LTCC based processing. The electrochemical analysis exhibits that the cofired path out-performs the postfiring path both at the anode and cathode. The reason is the formation of high surface area precipitated whiskers. Self-constraint sintering is utilized to overcome the difficulties of the large difference of coefficient of thermal expansion (CTE) between silver and LTCC (Dupont 951) tape during cofiring. The graphite sheet employed as a cavity fugitive insert guarantees cavity dimension conservation. Finally, performance of the membrane electrode assembly (MEA) with the porous silver electrode in the regular graphite electrode based cell and the integrated cofired cell is measured under passive fuel feeding condition. The MEA of the regular cell performs better as the electrode porosity and temperature increased. The power density of 10 mWcm-2 was obtained at ambient conditions with 1M methanol and it increased to 16 mWcm -2 at 50°C from an open circuit voltage of 0.58V. For the integrated prototype cell, the best performance, which depends on the balance methanol crossover and mass transfer at different temperatures and methanol concentrations, reaches 1.13 mWcm-2 at 2M methanol

  6. Fuel cell CO sensor

    DOEpatents

    Grot, Stephen Andreas; Meltser, Mark Alexander; Gutowski, Stanley; Neutzler, Jay Kevin; Borup, Rodney Lynn; Weisbrod, Kirk

    1999-12-14

    The CO concentration in the H.sub.2 feed stream to a PEM fuel cell stack is monitored by measuring current and/or voltage behavior patterns from a PEM-probe communicating with the reformate feed stream. Pattern recognition software may be used to compare the current and voltage patterns from the PEM-probe to current and voltage telltale outputs determined from a reference cell similar to the PEM-probe and operated under controlled conditions over a wide range of CO concentrations in the H.sub.2 fuel stream. A CO sensor includes the PEM-probe, an electrical discharge circuit for discharging the PEM-probe to monitor the CO concentration, and an electrical purging circuit to intermittently raise the anode potential of the PEM-probe's anode to at least about 0.8 V (RHE) to electrochemically oxidize any CO adsorbed on the probe's anode catalyst.

  7. Fuel cell CO sensor

    SciTech Connect

    Grot, S.A.; Meltser, M.A.; Gutowski, S.; Neutzler, J.K.; Borup, R.L.; Weisbrod, K.

    1999-12-14

    The CO concentration in the H{sub 2} feed stream to a PEM fuel cell stack is monitored by measuring current and/or voltage behavior patterns from a PEM-probe communicating with the reformate feed stream. Pattern recognition software may be used to compare the current and voltage patterns from the PEM-probe to current and voltage telltale outputs determined from a reference cell similar to the PEM-probe and operated under controlled conditions over a wide range of CO concentrations in the H{sub 2} fuel stream. A CO sensor includes the PEM-probe, an electrical discharge circuit for discharging the PEM-probe to monitor the CO concentration, and an electrical purging circuit to intermittently raise the anode potential of the PEM-probe's anode to at least about 0.8 V (RHE) to electrochemically oxidize any CO adsorbed on the probe's anode catalyst.

  8. Processing and Mechanical Properties of Various Zirconia/Alumina Composites for Fuel Cell Applications

    NASA Technical Reports Server (NTRS)

    Choi, Sung R.; Bansal, Narottam P.

    2002-01-01

    Various electrolyte materials for solid oxide fuel cells were fabricated by hot pressing 10 mol% yttria-stabilized zirconia (10-YSZ) reinforced with two different forms of alumina, particulates and platelets, each containing 0 to 30 mol% alumina. Flexure strength and fracture toughness of both particulate and platelet composites at ambient temperature increased with increasing alumina content, reaching a maximum at 30 mot% alumina. For a given alumina content, strength of particulate composites was greater than that of platelet composites, whereas, the difference in fracture toughness between the two composite systems was negligible. No virtual difference in elastic modulus and density was observed for a given alumina content between particulate and platelet composites. Thermal cycling up to 10 cycles between 200 to 1000 C did not show any effect on strength degradation of the 30 mol% platelet composites, indicative of negligible influence of CTE mismatches between YSZ matrix and alumina grains.

  9. Glass-ceramic sealant for solid oxide fuel cells application: Characterization and performance in dual atmosphere

    NASA Astrophysics Data System (ADS)

    Sabato, A. G.; Cempura, G.; Montinaro, D.; Chrysanthou, A.; Salvo, M.; Bernardo, E.; Secco, M.; Smeacetto, F.

    2016-10-01

    A glass-ceramic composition was designed and tested for use as a sealant in solid oxide fuel cell (SOFC) planar stack design. The crystallization behaviour was investigated by calculating the Avrami parameter (n) and the activation energy for crystallization (Ec) was obtained. The calculated values for n and Ec were 3 and 413.5 kJ/mol respectively. The results of thermal analyses indicate that this composition shows no overlap between the sintering and crystallization stages and thus an almost pore-free sealant can be deposited and sintered at 850 °C in air for 30 min. A gas tightness test has been carried out at 800 °C for 1100 h in dual atmosphere (Ar-H2 and air) without recording any leakage. Morphological and crystalline phase analyses were conducted prior and following tests in dual atmospheres in order to assess the compatibility of the proposed sealant with the metallic interconnect.

  10. Laser surface treatment of porous ceramic substrate for application in solid oxide fuel cells

    NASA Astrophysics Data System (ADS)

    Mahmod, D. S. A.; Khan, A. A.; Munot, M. A.; Glandut, N.; Labbe, J. C.

    2016-08-01

    Laser has offered a large number of benefits for surface treatment of ceramics due to possibility of localized heating, very high heating/cooling rates and possibility of growth of structural configurations only produced under non-equilibrium high temperature conditions. The present work investigates oxidation of porous ZrB2-SiC sintered ceramic substrates through treatment by a 1072 ± 10 nm ytterbium fiber laser. A multi-layer structure is hence produced showing successively oxygen rich distinct layers. The porous bulk beneath these layers remained unaffected as this laser-formed oxide scale and protected the substrate from oxidation. A glassy SiO2 structure thus obtained on the surface of the substrate becomes subject of interest for further research, specifically for its utilization as solid protonic conductor in Solid Oxide Fuel Cells (SOFCs).

  11. Thin catalyst layers based on carbon nanotubes for PEM-fuel cell applications

    NASA Astrophysics Data System (ADS)

    Bohnenberger, T.; Matovic, J.; Schmid, U.

    2011-06-01

    In this study, two approaches are compared to develop thin, multifunctional films of carbon nanotubes (CNT) which are targeted to serve as a catalyst layer in fuel cells. The first is based on the direct deposition of mixed multi- and single-wall CNTs on metalized silicon wafers, using the metallization as a sacrificial layer to subsequently detach the CNT film from the substrate. It is a less time consuming and a straight forward method compared to the alternative under investigation, the layer-by-layer technique (LbL). The LbL uses bilayers of charged nanotubes to slowly build up a film with an exactly defined thickness. The process is well controlled, but the time constants for deposition of each bilayer are rather high (i.e. about 1 h). With additional annealing steps implemented during film generation this method, however, is regarded advantageous as membranes results with improved mechanical stability and a good homogeneity.

  12. Catalyst inks and method of application for direct methanol fuel cells

    DOEpatents

    Zelenay, Piotr; Davey, John; Ren, Xiaoming; Gottesfeld, Shimshon; Thomas, Sharon C.

    2004-02-24

    Inks are formulated for forming anode and cathode catalyst layers and applied to anode and cathode sides of a membrane for a direct methanol fuel cell. The inks comprise a Pt catalyst for the cathode and a Pt--Ru catalyst for the anode, purified water in an amount 4 to 20 times that of the catalyst by weight, and a perfluorosulfonic acid ionomer in an amount effective to provide an ionomer content in the anode and cathode surfaces of 20% to 80% by volume. The inks are prepared in a two-step process while cooling and agitating the solutions. The final solution is placed in a cooler and continuously agitated while spraying the solution over the anode or cathode surface of the membrane as determined by the catalyst content.

  13. Nanostructured polypyrrole/carbon composite as Pt catalyst support for fuel cell applications

    NASA Astrophysics Data System (ADS)

    Zhao, Hongbin; Li, Lei; Yang, Jun; Zhang, Yongming

    A novel catalyst support was synthesized by in situ chemical oxidative polymerization of pyrrole on Vulcan XC-72 carbon in naphthalene sulfonic acid (NSA) solution containing ammonium persulfate as oxidant at room temperature. Pt nanoparticles with 3-4 nm size were deposited on the prepared polypyrrole-carbon composites by chemical reduction method. Scanning electron microscopy and transmission electron microscopy measurements showed that Pt particles were homogeneously dispersed in polypyrrole-carbon composites. The Pt nanoparticles-dispersed catalyst composites were used as anodes of fuel cells for hydrogen and methanol oxidation. Cyclic voltammetry measurements of hydrogen and methanol oxidation showed that Pt nanoparticles deposited on polypyrrole-carbon with NSA as dopant exhibit better catalytic activity than those on plain carbon. This result might be due to the higher electrochemically available surface areas, electronic conductivity and easier charge-transfer at polymer/carbon particle interfaces allowing a high dispersion and utilization of deposited Pt nanoparticles.

  14. Slurry-Based Chemical Hydrogen Storage Systems for Automotive Fuel Cell Applications

    SciTech Connect

    Brooks, Kriston P.; Semelsberger, Troy; Simmons, Kevin L.; Van Hassel, Bart A.

    2014-05-30

    In this paper, the system designs for hydrogen storage using chemical hydrogen materials in an 80 kWe fuel cell, light-duty vehicle are described. Ammonia borane and alane are used for these designs to represent the general classes of exothermic and endothermic materials. The designs are then compared to the USDRIVE/DOE developed set of system level targets for on-board storage. While most of the DOE targets are predicted to be achieved based on the modeling, the system gravimetric and volumetric densities were more challenging and became the focus of this work. The resulting system evaluation determined that the slurry is majority of the system mass. Only modest reductions in the system mass can be expected with improvements in the balance of plant components. Most of the gravimetric improvements will require developing materials with higher inherent storage capacity or by increasing the solids loading of the chemical hydrogen storage material in the slurry.

  15. Optimizing end-group cross-linking polymer electrolytes for fuel cell applications

    SciTech Connect

    Kim, Yu Seung; Lee, Kwan Soo; Jeong, Myung - Hwan; Lee, Jae - Suk

    2009-01-01

    This paper demonstrates the optimization of proton conductivity and water uptake for cross-linkable polymer electrolytes through synthesis and characterization of end-group cross-linkable sulfonated poly(arylene ether) copolymers (ESF-BPs). The extent of reaction of cross-linking was controlled by reaction time resulting in a series of polymers with two, independent tunable parameters, degree of sulfonation (DS) and degree of cross-linking (DC). For the polymers presented, cross-linking improved proton conductivity while reducing water uptake, an uncommon trend in polymer electrolytes where water is critical for proton conduction. Other trends relating to changes are reported and the results yield insight into the role of DS and DC and how to optimize electrochemical properties and performance of polymer electrolytes through these tunable parameters. Select polymer electrolytes were tested in fuel cells where performance and durability with accelerated relative humidity cycling were compared with Nafion{reg_sign}.

  16. Carbonate fuel cell matrix

    DOEpatents

    Farooque, Mohammad; Yuh, Chao-Yi

    1996-01-01

    A carbonate fuel cell matrix comprising support particles and crack attenuator particles which are made platelet in shape to increase the resistance of the matrix to through cracking. Also disclosed is a matrix having porous crack attenuator particles and a matrix whose crack attenuator particles have a thermal coefficient of expansion which is significantly different from that of the support particles, and a method of making platelet-shaped crack attenuator particles.

  17. Fuel cell technology program

    NASA Technical Reports Server (NTRS)

    1971-01-01

    The results of a solid polymer electrolyte fuel cell development program are summarized. A base line design was defined, and materials and components of the base line configuration were fabricated and tested. Concepts representing base line capability extensions in the areas of life, power, specific weight and volume, versatility of operation, field maintenance, and thermal control were identified and evaluated. Liaison and coordination with space shuttle contractors resulted in the exchange of engineering data.

  18. Carbonate fuel cell matrix

    DOEpatents

    Farooque, M.; Yuh, C.Y.

    1996-12-03

    A carbonate fuel cell matrix is described comprising support particles and crack attenuator particles which are made platelet in shape to increase the resistance of the matrix to through cracking. Also disclosed is a matrix having porous crack attenuator particles and a matrix whose crack attenuator particles have a thermal coefficient of expansion which is significantly different from that of the support particles, and a method of making platelet-shaped crack attenuator particles. 8 figs.

  19. Fuel cell oxygen electrode

    DOEpatents

    Shanks, H.R.; Bevolo, A.J.; Danielson, G.C.; Weber, M.F.

    An oxygen electrode for a fuel cell utilizing an acid electrolyte has a substrate of an alkali metal tungsten bronze of the formula: A/sub x/WO/sub 3/ where A is an alkali metal and x is at least 0.2, which is covered with a thin layer of platinum tungsten bronze of the formula: Pt/sub y/WO/sub 3/ where y is at least 0.8.

  20. Fuel cell oxygen electrode

    DOEpatents

    Shanks, Howard R.; Bevolo, Albert J.; Danielson, Gordon C.; Weber, Michael F.

    1980-11-04

    An oxygen electrode for a fuel cell utilizing an acid electrolyte has a substrate of an alkali metal tungsten bronze of the formula: A.sub.x WO.sub.3 where A is an alkali metal and x is at least 0.2, which is covered with a thin layer of platinum tungsten bronze of the formula: Pt.sub.y WO.sub.3 where y is at least 0.8.

  1. Fuel cell current collector

    DOEpatents

    Katz, Murray; Bonk, Stanley P.; Maricle, Donald L.; Abrams, Martin

    1991-01-01

    A fuel cell has a current collector plate (22) located between an electrode (20) and a separate plate (25). The collector plate has a plurality of arches (26, 28) deformed from a single flat plate in a checkerboard pattern. The arches are of sufficient height (30) to provide sufficient reactant flow area. Each arch is formed with sufficient stiffness to accept compressive load and sufficient resiliently to distribute the load and maintain electrical contact.

  2. Nafion/PTFE composite membranes for direct methanol fuel cell applications

    NASA Astrophysics Data System (ADS)

    Lin, Hsiu-Li; Yu, T. Leon; Huang, Li-Ning; Chen, Li-Chung; Shen, Kun-Sheng; Jung, Guo-Bin

    Using dynamic light scattering and scanning electron microscope (SEM), it is shown that a high-carbon-number alcohol/water, i.e., 2-propanol/water, mixed solvent is more effective than low-carbon-number alcohol/water, i.e., ethanol/water and methanol/water, mixed solvents in dispersing Nafion molecules. Thus, it is a better solvent for the preparation of Nafion/PTFE (poly(tetrafluoroethylene)) composite membranes. The performance of direct methanol fuel cells (DMFCs) with a Nafion/PTFE composite membrane, which was prepared in-house, a commercial Nafion-117 membrane, or a commercial Nafion-112 membrane were investigated by feeding various concentrations, i.e., 2-5 M, of methanol to the anode. The Nafion/PTFE composite membrane gave a better DMFC performance than that obtained with Nafion-117 or Nafion-112 membranes. Using a DMFC model and varying the methanol concentration at the anode, cell voltage data were analyzed with respect to methanol concentration and cell current. The results indicate that inserting porous PTFE into Nafion polymer causes a reduction not only in methanol diffusion cross-over but also in the electro-osmosis of methanol cross-over in the membrane.

  3. Metal foams application to enhance cooling of open cathode polymer electrolyte membrane fuel cells

    NASA Astrophysics Data System (ADS)

    Sajid Hossain, Mohammad; Shabani, Bahman

    2015-11-01

    Conventional channel flow fields of open cathode Polymer Electrolyte Membrane Fuel Cells (PEMFCs) introduce some challenges linked to humidity, temperature, pressure and oxygen concentration gradients along the conventional flow fields that reduce the cell performance. According to previous experimental reports, with conventional air flow fields, hotspot formation due to water accumulation in Gas Diffusion Layer (GDL) is common. Unlike continuous long flow passages in conventional channels, metal foams provide randomly interrupted flow passages. Re-circulation of fluid, due to randomly distributed tortuous ligaments, enhances temperature and humidity uniformity in the fluid. Moreover, the higher electrical conductivity of metal foams compared to non-metal current collectors and their very low mass density compared to solid metal materials are expected to increase the electrical performance of the cell while significantly reducing its weight. This article reviews the existing cooling systems and identifies the important parameters on the basis of reported literature in the air cooling systems of PEMFCs. This is followed by investigating metal foams as a possible option to be used within the structure of such PEMFCs as an option that can potentially address cooling and flow distribution challenges associated with using conventional flow channels, especially in air-cooled PEMFCs.

  4. Fuel utilization and fuel sensitivity of solid oxide fuel cells

    NASA Astrophysics Data System (ADS)

    Huang, Kevin

    2011-03-01

    Fuel utilization and fuel sensitivity are two important process variables widely used in operation of SOFC cells, stacks, and generators. To illustrate the technical values, the definitions of these two variables as well as practical examples are particularly given in this paper. It is explicitly shown that the oxygen-leakage has a substantial effect on the actual fuel utilization, fuel sensitivity and V-I characteristics. An underestimation of the leakage flux could potentially results in overly consuming fuel and oxidizing Ni-based anode. A fuel sensitivity model is also proposed to help extract the leakage flux information from a fuel sensitivity curve. Finally, the "bending-over" phenomenon observed in the low-current range of a V-I curve measured at constant fuel-utilization is quantitatively coupled with leakage flux.

  5. Fuel cell systems program plan, Fiscal year 1994

    SciTech Connect

    Not Available

    1994-07-01

    Goal of the fuel cell program is to increase energy efficiency and economic effectiveness through development and commercialization of fuel cell systems which operate on fossil fuels in multiple end use sectors. DOE is participating with the private sector in sponsoring development of molten carbonate fuel cells and solid oxide fuel cells for application in the utility, commercial, and industrial sectors. Commercialization of phosphoric acid fuel cells is well underway. Besides the introduction, this document is divided into: goal/objectives, program strategy, technology description, technical status, program description/implementation, coordinated fuel cell activities, and international activities.

  6. Status of commercial fuel cell powerplant system development

    NASA Technical Reports Server (NTRS)

    Warshay, Marvin

    1987-01-01

    The primary focus is on the development of commercial Phosphoric Acid Fuel Cell (PAFC) powerplant systems because the PAFC, which has undergone extensive development, is currently the closest fuel cell system to commercialization. Shorter discussions are included on the high temperature fuel cell systems which are not as mature in their development, such as the Molten Carbonate Fuel Cell (MCFC) and the Solid Oxide Fuel Cell (SOFC). The alkaline and the Solid Polymer Electrolyte (SPE) fuel cell systems, are also included, but their discussions are limited to their prospects for commercial development. Currently, although the alkaline fuel cell continues to be used for important space applications there are no commercial development programs of significant size in the USA and only small efforts outside. The market place for fuel cells and the status of fuel cell programs in the USA receive extensive treatment. The fuel cell efforts outside the USA, especially the large Japanese programs, are also discussed.

  7. A Novel Non-Platinum Group Electrocatalyst for PEM Fuel Cell Application

    SciTech Connect

    Kim, Jin Yong; Oh, Takkeun; Shin, Yongsoon; Bonnett, Jeff F.; Weil, K. Scott

    2011-04-01

    Precious-metal catalysts (predominantly Pt or Pt-based alloys supported on carbon) have traditionally been used to catalyze the electrode reactions in polymer electrolyte membrane (PEM) fuel cells. However as PEM fuel systems begin to approach commercial reality, there is an impending need to replace Pt with a lower cost alternative. The present study investigates the performance of a carbon-supported tantalum oxide material as a potential oxygen reduction reaction (ORR) catalyst for use on the cathode side of the PEM fuel cell membrane electrode assembly. Although bulk tantalum oxide tends to exhibit poor electrochemical performance due to limited electrical conductivity, it displays a high oxygen reduction potential; one that is comparable to Pt. Analysis of the Pourbaix electrochemical equilibrium database also indicates that tantalum oxide (Ta2O5) is chemically stable under the pH and applied potential conditions to which the cathode catalyst is typically exposed during stack operation. Nanoscale tantalum oxide catalysts were fabricated using two approaches, by reactive oxidation sputtering and by direct chemical synthesis, each carried out on a carbon support material. Nanoscale tantalum oxide particles measuring approximately 6nm in size that were sputtered onto carbon paper exhibited a mass-specific current density as high as one-third that of Pt when measured at 0.6V vs. NHE. However because of the two-dimensional nature of this particle-on-paper structure, which limits the overall length of the triple phase boundary junctions where the oxide, carbon paper, and aqueous electrolyte meet, the corresponding area-specific current density was quite low. The second synthesis approach yielded a more extended, three-dimensional structure via chemical deposition of nanoscale tantalum oxide particles on carbon powder. These catalysts exhibited a high ORR onset potential, comparable to that of Pt, and displayed a significant improvement in the area-specific current

  8. An investigation of a carbon dioxide-based fuel cell system as a power generation alternative for Mars exploration applications

    NASA Astrophysics Data System (ADS)

    Salinas Mejia, Oscar Roberto

    The possibility of using a bifunctional carbon dioxide-based fuel cell system as the core of a propulsion system for a Mars exploration rotorcraft is investigated here. This concept involves the production of electricity by a stack of fuel cells that rely on carbon monoxide as the fuel and oxygen as the oxidizer. These two reactants are harvested from the Martian atmosphere by employing the same stack of cells as an electrolyzing unit. The general objectives of this research are to: prove the feasibility of the concept, produce a comprehensive model that allows the prediction of performance, and offer recommendations for the successful implementation of the concept. In this work, it is pointed out and demonstrated that, at least in theory, the overall electrochemical reaction required by this concept can be achieved by transporting hydrogen protons, hydroxyl radicals, carbonate radicals, or oxygen ions between the electrodes. Complete sets of reactions are prescribed for different types of fuel cells. Anodic and cathodic reactions are presented for acid, alkaline, carbonate, and solid oxide electrolytes. Subsequently, a more detailed consideration of all relevant phenomena is done by coupling elements of chemical kinetics, electrodics, electrochemistry, and thermodynamics with experimental data, to complete the demonstration of the feasibility of the carbon dioxide-based bifunctional fuel cell system. The understanding and inclusion of key processes and mechanisms allows the construction of a model that predicts the performance of the power generation subsystem advocated here. The model adopted in this work couples mechanistics with elements derived from the application of linear regression modeling techniques. Mechanistics are used to determine: thermodynamic equilibrium potential, overvoltages due to activation, ohmic resistance, and mass transport. This approach is empirical in part because the numerical parametric expressions suggested here have to be precised

  9. Ambient pressure fuel cell system

    DOEpatents

    Wilson, Mahlon S.

    2000-01-01

    An ambient pressure fuel cell system is provided with a fuel cell stack formed from a plurality of fuel cells having membrane/electrode assemblies (MEAs) that are hydrated with liquid water and bipolar plates with anode and cathode sides for distributing hydrogen fuel gas and water to a first side of each one of the MEAs and air with reactant oxygen gas to a second side of each one of the MEAs. A pump supplies liquid water to the fuel cells. A recirculating system may be used to return unused hydrogen fuel gas to the stack. A near-ambient pressure blower blows air through the fuel cell stack in excess of reaction stoichiometric amounts to react with the hydrogen fuel gas.

  10. Large stationary fuel cell systems: Status and dynamic requirements

    NASA Astrophysics Data System (ADS)

    Bischoff, Manfred

    Molten carbonate fuel cell demonstrations to-date, have been able to show the highest fuel-to-electricity conversion efficiencies (>50%) of any stand-alone fuel cell type. The primary developer of this type of fuel cell in United States is Fuel Cell Energy Corporation (FCE), the developer and manufacturer of the Direct FuelCell ™ concept. FCE and MTU CFC Solutions in Germany, a licensee of FCE have demonstrated carbonate fuel cells from 10 kW to 2 MW of electrical output on a variety of fuels. IHI in Japan are also developing carbonate fuel cells for stationary power and have recently successfully demonstrated the technology in Kawagoe, Japan. In Italy, Ansaldo fuel cell have demonstrated a 100 kW carbonate fuel cell in Milan. In Korea, the Ministry of Commerce, Industry and Energy has committed to install 300 fuel cell units, sized 250 kW to 1 MW, for distributed power generation by 2012. Carbonate fuel cell technology is more fuel flexible than lower temperature fuel cell technologies and is well suited for on-site stationary CHP applications as well as to marine, military, and traction applications. The present paper gives an overview about the commercialisation efforts for the molten carbonate fuel cell technology.

  11. Application of proton exchange membrane fuel cells for the monitoring and direct usage of biohydrogen produced by Chlamydomonas reinhardtii

    NASA Astrophysics Data System (ADS)

    Oncel, S.; Vardar-Sukan, F.

    Photo-biologically produced hydrogen by Chlamydomonas reinhardtii is integrated with a proton exchange (PEM) fuel cell for online electricity generation. To investigate the fuel cell efficiency, the effect of hydrogen production on the open circuit fuel cell voltage is monitored during 27 days of batch culture. Values of volumetric hydrogen production, monitored by the help of the calibrated water columns, are related with the open circuit voltage changes of the fuel cell. From the analysis of this relation a dead end configuration is selected to use the fuel cell in its best potential. After the open circuit experiments external loads are tested for their effects on the fuel cell voltage and current generation. According to the results two external loads are selected for the direct usage of the fuel cell incorporating with the photobioreactors (PBR). Experiments with the PEM fuel cell generate a current density of 1.81 mA cm -2 for about 50 h with 10 Ω load and 0.23 mA cm -2 for about 80 h with 100 Ω load.

  12. Mass Production Cost Estimation For Direct H2 PEM Fuel Cell Systesm for Automotive Applications. 2010 Update

    SciTech Connect

    James, Brian D.; Kalinoski, Jeffrey A.; Baum, Kevin N.

    2010-09-30

    This report is the fourth annual update of a comprehensive automotive fuel cell cost analysis. It contains estimates for material and manufacturing costs of complete 80 kWnet direct-hydrogen proton exchange membrane fuel cell systems suitable for powering light-duty automobiles.

  13. Mass Production Cost Estimation for Direct H2 PEM Fuel Cell Systems for Automotive Applications. 2009 Update

    SciTech Connect

    James, Brian D.; Kalinoski, Jeffrey A.; Baum, Kevin N.

    2010-01-01

    This report is the third annual update of a comprehensive automotive fuel cell cost analysis. It contains estimates for material and manufacturing cost of complete 80 kWnet direct hydrogen proton exchange membrane fuel cell systems suitable for powering light duty automobiles.

  14. Reversible (unitized) PEM fuel cell devices

    SciTech Connect

    Mitlitsky, F; Myers, B; Smith, W F; Weisberg, Molter, T M

    1999-06-01

    Regenerative fuel cells (RFCs) are enabling for many weight-critical portable applications, since the packaged specific energy (>400 Wh/kg) of properly designed lightweight RFC systems is several-fold higher than that of the lightest weight rechargeable batteries. RFC systems can be rapidly refueled (like primary fuel cells), or can be electrically recharged (like secondary batteries) if a refueling infrastructure is not conveniently available. Higher energy capacity systems with higher performance, reduced weight, and freedom from fueling infrastructure are the features that RFCs promise for portable applications. Reversible proton exchange membrane (PEM) fuel cells, also known as unitized regenerative fuel cells (URFCs), or reversible regenerative fuel cells, are RFC systems which use reversible PEM cells, where each cell is capable of operating both as a fuel cell and as an electrolyzer. URFCs further economize portable device weight, volume, and complexity by combining the functions of fuel cells and electrolyzers in the same hardware, generally without any system performance or efficiency reduction. URFCs are being made in many forms, some of which are already small enough to be portable. Lawrence Livermore National Laboratory (LLNL) has worked with industrial partners to design, develop, and demonstrate high performance and high cycle life URFC systems. LLNL is also working with industrial partners to develop breakthroughs in lightweight pressure vessels that are necessary for URFC systems to achieve the specific energy advantages over rechargeable batteries. Proton Energy Systems, Inc. (Proton) is concurrently developing and commercializing URFC systems (UNIGEN' product line), in addition to PEM electrolyzer systems (HOGEN' product line), and primary PEM fuel cell systems. LLNL is constructing demonstration URFC units in order to persuade potential sponsors, often in their own conference rooms, that advanced applications based on URFC s are feasible. Safety

  15. Processing of LaCrO{sub 3} for solid oxide fuel cell applications

    SciTech Connect

    Huebner, W.; Anderson, H.U.

    1994-09-01

    The University of Missouri-Rolla is performing a 5 year research program dedicated towards the development of LaCrO{sub 3}-based interconnect powders which densify when in contact with anode and cathode materials for solid oxide fuel cells (SOFC). During the course of this program the authors investigated compositions within the pseudo-ternary LaCrO{sub 3}-LaMnO{sub 3}-LaCoO{sub 3} system. Their expanded studies on the processing and sintering of LaCrO{sub 3} to make dense interconnects using LaCrO{sub 3}-based oxides at temperatures less than 1,500 C in an air atmosphere and in contact with both anode and cathode oxides. The specific objectives of this research program are to: Develop a novel technique which reproducibly yields LaCrO{sub 3}-based powders with the desired particle characteristics; Fully understand the liquid phase sintering mechanism; Clearly identify the reason why LaCrO{sub 3} does not densify in the presence of electrolyte and cathode materials; Systematically solve this problem through judicious control over the liquid phase; and Incorporate materials developed in this program into planar cells and measure their performance. Results are discussed on porosity and skrinkage, and sintering and melting behaviors.

  16. An Overview of Stationary Fuel Cell Technology

    SciTech Connect

    DR Brown; R Jones

    1999-03-23

    Technology developments occurring in the past few years have resulted in the initial commercialization of phosphoric acid (PA) fuel cells. Ongoing research and development (R and D) promises further improvement in PA fuel cell technology, as well as the development of proton exchange membrane (PEM), molten carbonate (MC), and solid oxide (SO) fuel cell technologies. In the long run, this collection of fuel cell options will be able to serve a wide range of electric power and cogeneration applications. A fuel cell converts the chemical energy of a fuel into electrical energy without the use of a thermal cycle or rotating equipment. In contrast, most electrical generating devices (e.g., steam and gas turbine cycles, reciprocating engines) first convert chemical energy into thermal energy and then mechanical energy before finally generating electricity. Like a battery, a fuel cell is an electrochemical device, but there are important differences. Batteries store chemical energy and convert it into electrical energy on demand, until the chemical energy has been depleted. Depleted secondary batteries may be recharged by applying an external power source, while depleted primary batteries must be replaced. Fuel cells, on the other hand, will operate continuously, as long as they are externally supplied with a fuel and an oxidant.

  17. Environmental and economic assessment of a cracked ammonia fuelled alkaline fuel cell for off-grid power applications

    NASA Astrophysics Data System (ADS)

    Cox, Brian; Treyer, Karin

    2015-02-01

    Global mobile telecommunication is possible due to millions of Base Transceiver Stations (BTS). Nearly 1 million of these are operating off-grid, typically powered by diesel generators and therefore leading to significant CO2 emissions and other environmental burdens. A novel type of Alkaline Fuel Cell (AFC) powered by cracked ammonia is being developed for replacement of these generators. This study compares the environmental and economic performance of the two systems by means of Life Cycle Assessment (LCA) and Levelised Cost of Electricity (LCOE), respectively. Results show that the production of ammonia dominates the LCA results, and that renewable ammonia production pathways greatly improve environmental performance. Sensitivity analyses reveal that the fuel cell parameters that most affect system cost and environmental burdens are cell power density and lifetime and system efficiency. Recycling of anode catalyst and electrode substrate materials is found to have large impacts on environmental performance, though without large cost incentives. For a set of target parameter values and fossil sourced ammonia, the AFC is calculated to produce electricity with life cycle CO2 eq emissions of 1.08 kg kWh-1, which is 23% lower than a diesel generator with electricity costs that are 14% higher in the same application.

  18. Fuel cell system with interconnect

    DOEpatents

    Liu, Zhien; Goettler, Richard; Delaforce, Philip Mark

    2016-03-08

    The present invention includes a fuel cell system having an interconnect that reduces or eliminates diffusion (leakage) of fuel and oxidant by providing an increased densification, by forming the interconnect as a ceramic/metal composite.

  19. Intermolecular ionic cross-linked sulfonated poly(ether ether ketone) membranes containing diazafluorene for direct methanol fuel cell applications

    NASA Astrophysics Data System (ADS)

    Liang, Yu; Gong, Chenliang; Qi, Zhigang; Li, Hui; Wu, Zhongying; Zhang, Yakui; Zhang, Shujiang; Li, Yanfeng

    2015-06-01

    A series of novel ionic cross-linking sulfonated poly(ether ether ketone) (SPEEK) membranes containing the diazafluorene functional group are synthesized to reduce the swelling ratio and methanol permeability for direct methanol fuel cell (DMFC) applications. The ionic cross-linking is realized by the interaction between sulfonic acid groups and pyridyl in diazafluorene. The prepared membranes exhibit good mechanical properties, adequate thermal stability, good oxidative stability, appropriate water uptake and low swelling ratio. Moreover, the ionic cross-linked membranes exhibit lower methanol permeability in the range between 0.56 × 10-7 cm2 s-1 and 1.8 × 10-7 cm2 s-1, which is lower than Nafion 117, and they exhibit higher selectivity than Nafion 117 at 30 °C on the basis of applicable proton conductivity.

  20. Low Temperature Constrained Sintering of Cerium Gadolinium OxideFilms for Solid Oxide Fuel Cell Applications

    SciTech Connect

    Nicholas, Jason Dale

    2007-01-01

    Cerium gadolinium oxide (CGO) has been identified as an acceptable solid oxide fuel cell (SOFC) electrolyte at temperatures (500-700 C) where cheap, rigid, stainless steel interconnect substrates can be used. Unfortunately, both the high sintering temperature of pure CGO, >1200 C, and the fact that constraint during sintering often results in cracked, low density ceramic films, have complicated development of metal supported CGO SOFCs. The aim of this work was to find new sintering aids for Ce0.9Gd0.1O1.95, and to evaluate whether they could be used to produce dense, constrained Ce0.9Gd0.1O1.95 films at temperatures below 1000 C. To find the optimal sintering aid, Ce0.9Gd0.1O1.95 was doped with a variety of elements, of which lithium was found to be the most effective. Dilatometric studies indicated that by doping CGO with 3mol% lithium nitrate, it was possible to sinter pellets to a relative density of 98.5% at 800 C--a full one hundred degrees below the previous low temperature sintering record for CGO. Further, it was also found that a sintering aid's effectiveness could be explained in terms of its size, charge and high temperature mobility. A closer examination of lithium doped Ce0.9Gd0.1O1.95 indicated that lithium affects sintering by producing a Li2O-Gd2O3-CeO2 liquid at the CGO grain boundaries. Due to this liquid phase sintering, it was possible to produce dense, crack-free constrained films of CGO at the record low temperature of 950 C using cheap, colloidal spray deposition processes. This is the first time dense constrained CGO films have been produced below 1000 C and could help commercialize metal supported ceria based solid oxide fuel cells.

  1. A Total Cost of Ownership Model for Low Temperature PEM Fuel Cells in Combined Heat and Power and Backup Power Applications

    SciTech Connect

    University of California, Berkeley; Wei, Max; Lipman, Timothy; Mayyas, Ahmad; Chien, Joshua; Chan, Shuk Han; Gosselin, David; Breunig, Hanna; Stadler, Michael; McKone, Thomas; Beattie, Paul; Chong, Patricia; Colella, Whitney; James, Brian

    2014-06-23

    A total cost of ownership model is described for low temperature proton exchange membrane stationary fuel cell systems for combined heat and power (CHP) applications from 1-250kW and backup power applications from 1-50kW. System designs and functional specifications for these two applications were developed across the range of system power levels. Bottom-up cost estimates were made for balance of plant costs, and detailed direct cost estimates for key fuel cell stack components were derived using design-for-manufacturing-and-assembly techniques. The development of high throughput, automated processes achieving high yield are projected to reduce the cost for fuel cell stacks to the $300/kW level at an annual production volume of 100 MW. Several promising combinations of building types and geographical location in the U.S. were identified for installation of fuel cell CHP systems based on the LBNL modelling tool DER CAM. Life-cycle modelling and externality assessment were done for hotels and hospitals. Reduced electricity demand charges, heating credits and carbon credits can reduce the effective cost of electricity ($/kWhe) by 26-44percent in locations such as Minneapolis, where high carbon intensity electricity from the grid is displaces by a fuel cell system operating on reformate fuel. This project extends the scope of existing cost studies to include externalities and ancillary financial benefits and thus provides a more comprehensive picture of fuel cell system benefits, consistent with a policy and incentive environment that increasingly values these ancillary benefits. The project provides a critical, new modelling capacity and should aid a broad range of policy makers in assessing the integrated costs and benefits of fuel cell systems versus other distributed generation technologies.

  2. Chrysler Pentastar direct hydrogen fuel cell program

    SciTech Connect

    Kimble, M.; Deloney, D.

    1995-08-01

    The Chrysler Pentastar Electronics, Inc. Direct Hydrogen Fueled PEM Fuel Cell Hybrid Vehicle Program (DPHV) was initiated 1 July, 1994 with the following mission, {open_quotes}Design, fabricate, and test a Direct Hydrogen Fueled Proton Exchange Membrane (PEM) Fuel Cell System including onboard hydrogen storage, an efficient lightweight fuel cell, a gas management system, peak power augmentation and a complete system controls that can be economically mass produced and comply with all safety environmental and consumer requirements for vehicle applications for the 21st century.{close_quotes} The Conceptual Design for the entire system based upon the selection of an applicable vehicle and performance requirements that are consistent with the PNGV goals will be discussed. A Hydrogen Storage system that has been selected, packaged, and partially tested in accordance with perceived Hydrogen Safety and Infrastructure requirements will be discussed in addition to our Fuel Cell approach along with design of the {open_quotes}real{close_quotes} module. The Gas Management System and the Load Leveling System have been designed and the software programs have been developed and will be discussed along with a complete fuel cell test station that has the capability to test up to a 60 kW fuel cell system.

  3. Stationary power fuel cell commercialization status worldwide

    SciTech Connect

    Williams, M.C.

    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.

  4. In-situ diagnostic tools for hydrogen transfer leak characterization in PEM fuel cell stacks part I: R&D applications

    NASA Astrophysics Data System (ADS)

    Niroumand, Amir M.; Pooyanfar, Oldooz; Macauley, Natalia; DeVaal, Jake; Golnaraghi, Farid

    2015-03-01

    This paper describes a diagnostic tool for in-situ characterization of hydrogen transfer leak in individual cells of a Polymer Electrolyte Membrane (PEM) fuel cell stack, suitable for Research and Development (R&D) applications. The technique is based on supplying hydrogen and nitrogen to the anode and cathode of a PEM fuel cell stack while maintaining a prescribed anode overpressure. Under these conditions, hydrogen crosses over from the anode to the cathode, and the Open Circuit Voltage (OCV) represents the ratio of hydrogen partial pressure in the two electrodes. It is shown that by measuring temperature, pressure, flow, humidity, and individual OCVs, the proposed technique can accurately estimate the rate of hydrogen transfer leak in individual cells of a PEM fuel cell stack. This diagnostic tool is suitable for characterizing hydrogen transfer leaks during fuel cell R&D, as it only requires gasses and measurements that are readily available on fuel cell test stations, and does not need disassembling or modifying the fuel cell stack.

  5. Microbial fuel cells demonstrate high coulombic efficiency applicable for water remediation.

    PubMed

    Devasahayam, Mercy; Masih, Sam A

    2012-06-01

    Microbial fuel cells (MFCs) convert biomass into electricity by the metabolic activity of microorganisms and are also used for remediation and water treatment. Power output was compared for a dual chambered membrane MFC using either E. coli or two Yamuna river samples, Yamuna (before the Sangam region)--slow flow (sample 1) and Sangam region--fast flow (sample 2). E. coli and the two river water samples 1 and 2 gave a maximum voltage of 779, 463 and 415 mV respectively. Using E. coli the maximum power density obtained with a 100 omega resistor was 220.66 mW/cm2 and the highest power generated 6068.41 mW. The results demonstrate E. coli, river sample 1 and river sample 2 have a comparable coulombic efficiency of 85.2, 71 and 77% respectively when using 0.4% sucrose as substrate. The decrease in chemical oxidative demand of all river water samples using MFC technology demonstrates efficient remediation of inland water. PMID:22734255

  6. Parameters characterization and optimization of activated carbon (AC) cathodes for microbial fuel cell application.

    PubMed

    Santoro, Carlo; Artyushkova, Kateryna; Babanova, Sofia; Atanassov, Plamen; Ieropoulos, Ioannis; Grattieri, Matteo; Cristiani, Pierangela; Trasatti, Stefano; Li, Baikun; Schuler, Andrew J

    2014-07-01

    Activated carbon (AC) is employed as a cost-effective catalyst for cathodic oxygen reduction in microbial fuel cells (MFC). The fabrication protocols of AC-based cathodes are conducted at different applied pressures (175-3500 psi) and treatment temperatures (25-343°C). The effects of those parameters along with changes in the surface morphology and chemistry on the cathode performances are comprehensively examined. The cathodes are tested in a three-electrode setup and explored in single chamber membraneless MFCs (SCMFCs). The results show that the best performance of the AC-based cathode is achieved when a pressure of 1400 psi is applied followed by heat treatment of 150-200°C for 1h. The influence of the applied pressure and the temperature of the heat treatment on the electrodes and SCMFCs is demonstrated as the result of the variation in the transfer resistance, the surface morphology and surface chemistry of the AC-based cathodes tested.

  7. Highly active nanoscale Ni - Yttria stabilized zirconia anodes for micro-solid oxide fuel cell applications

    NASA Astrophysics Data System (ADS)

    Buyukaksoy, Aligul; Birss, Viola I.

    2016-03-01

    The optimum operating temperature of micro solid oxide fuel cells (μ-SOFCs) is < 600 °C, which normally results in an undesirably high internal resistance. While the resistance of the electrolyte (most commonly yttria stabilized zirconia, YSZ) can be lowered significantly simply by decreasing its thickness, minimization of the electrode resistance (thus maintaining rapid reaction kinetics) is not as straightforward. In this work, an ethylene glycol based polymeric precursor solution, which promotes the intimate mixing of the Ni, Y and Zr components prior to their crystallization as oxides, was spin-coated onto a YSZ disc, generating a nanocomposite NiO-YSZ thin film. The in-situ reduction of NiO phase within the dense NiO-YSZ film to Ni, in combination with the nanoscale size of the Ni and YSZ particles (ca. 25 nm), resulted in a nanoporous, Ni-YSZ anode morphology (thickness < 1 μm) with a homogeneous distribution of Ni and YSZ and a very high triple phase boundary length. Very small electrode polarization resistances of 0.65 Ω cm2 per electrode were obtained at 550 °C in humidified H2, the lowest values yet reported for SOFCs at this temperature. These highly active anodes are therefore very promising for use in next generation μ-SOFCs.

  8. [Application of Microbial Fuel Cells in Reducing Methane Emission from Rice Paddy].

    PubMed

    Deng, Huan; Cai, Lü-cheng; Jiang, Yun-bin; Zhong, Wen-hui

    2016-01-15

    We aimed to study whether the methane emission from rice paddy with straw return can be alleviated in microbial fuel cells (MFCs). In our study, the soil mixed with 0. 5% ( mass fraction) rice straw was packed into MFCs reactors, then flooded with excess of sterilized water and transplanted with rice seedlings followed by the operation of MFCs. The MFCs were operated for 98 days covering five stages of seeding, tillering, mid-season aeration, rice filling, and ripening. The voltage data were recorded continuously and in real time during the MFCs operation and the methane emitted was collected once a week using the static chamber method and the methane emission flux was determined by gas chromatography. The results showed that the MFCs current increased and reached the peak value in the seeding and tillering stages and the operation of MFCs significantly reduced the accumulative methane emission in these two stages. The possible reason could be that the electrogens competed with methanogens for organic substrates. The height, the above and below ground biomass, and the productivity of rice plants were not significantly affected by the 98-day operation of MFCs. Our study provides a potential green and sustainable technology for the reduction of CH, emission from rice paddy fields.

  9. Application of conductive polymers in biocathode of microbial fuel cells and microbial community.

    PubMed

    Li, Chao; Ding, Lili; Cui, Hao; Zhang, Libin; Xu, Ke; Ren, Hongqiang

    2012-07-01

    Four kinds of conductive polymers, polyaniline (PANI) and its co-polymers poly (aniline-co-o-aminophenol) (PANOA), poly (aniline-co-2, 4-diaminophenol) (PANDAP) and poly (aniline-1, 8-diaminonaphthalene) (PANDAN) were applied to modify carbon felts as the aerobic abiotic cathodes and biocathodes in microbial fuel cells (MFC). Compare to unmodified, all the four polymers can significantly improve the power densities for both abiotic cathodes (increased by 300%) and biocathodes (increased by 180%). The co-polymers with different functional groups introduction had further special advantages in MFC performance: PANOA and PANDAP with -OH showed less sensitivity to DO and pH change in cathode; PANDAP and PANDAN with -NH(3) provided better attachment condition for biofilm which endowed them higher power output. With the help of conductive polymer coats, the cathode biofilm became thicker, and according to biodiversity analysis, the predominated phyla changed from β-Proteobacteria (unmodified) to α, γ-Proteobacteria (modified), which may be responsible for the superiority of the modified MFCs.

  10. Parameters characterization and optimization of activated carbon (AC) cathodes for microbial fuel cell application.

    PubMed

    Santoro, Carlo; Artyushkova, Kateryna; Babanova, Sofia; Atanassov, Plamen; Ieropoulos, Ioannis; Grattieri, Matteo; Cristiani, Pierangela; Trasatti, Stefano; Li, Baikun; Schuler, Andrew J

    2014-07-01

    Activated carbon (AC) is employed as a cost-effective catalyst for cathodic oxygen reduction in microbial fuel cells (MFC). The fabrication protocols of AC-based cathodes are conducted at different applied pressures (175-3500 psi) and treatment temperatures (25-343°C). The effects of those parameters along with changes in the surface morphology and chemistry on the cathode performances are comprehensively examined. The cathodes are tested in a three-electrode setup and explored in single chamber membraneless MFCs (SCMFCs). The results show that the best performance of the AC-based cathode is achieved when a pressure of 1400 psi is applied followed by heat treatment of 150-200°C for 1h. The influence of the applied pressure and the temperature of the heat treatment on the electrodes and SCMFCs is demonstrated as the result of the variation in the transfer resistance, the surface morphology and surface chemistry of the AC-based cathodes tested. PMID:24787317

  11. [Application of Microbial Fuel Cells in Reducing Methane Emission from Rice Paddy].

    PubMed

    Deng, Huan; Cai, Lü-cheng; Jiang, Yun-bin; Zhong, Wen-hui

    2016-01-15

    We aimed to study whether the methane emission from rice paddy with straw return can be alleviated in microbial fuel cells (MFCs). In our study, the soil mixed with 0. 5% ( mass fraction) rice straw was packed into MFCs reactors, then flooded with excess of sterilized water and transplanted with rice seedlings followed by the operation of MFCs. The MFCs were operated for 98 days covering five stages of seeding, tillering, mid-season aeration, rice filling, and ripening. The voltage data were recorded continuously and in real time during the MFCs operation and the methane emitted was collected once a week using the static chamber method and the methane emission flux was determined by gas chromatography. The results showed that the MFCs current increased and reached the peak value in the seeding and tillering stages and the operation of MFCs significantly reduced the accumulative methane emission in these two stages. The possible reason could be that the electrogens competed with methanogens for organic substrates. The height, the above and below ground biomass, and the productivity of rice plants were not significantly affected by the 98-day operation of MFCs. Our study provides a potential green and sustainable technology for the reduction of CH, emission from rice paddy fields. PMID:27078978

  12. Catalysts for ultrahigh current density oxygen cathodes for space fuel cell applications

    NASA Technical Reports Server (NTRS)

    Tryk, D.; Yeager, E.; Shingler, M.; Aldred, W.; Wang, C.

    1990-01-01

    The objective of this research was to identify promising electrocatalyst/support systems for the oxygen cathode in alkaline fuel cells operating at relatively high temperatures, O2 pressures and current densities. A number of materials were prepared, including Pb-Ru and Pb-Ir pyrochlores, RuO2 and Pt-doped RuO2, and lithiated NiO. Several of these were prepared using techniques that had not been previously used to prepare them. Particularly interesting is the use of the alkaline solution technique to prepare the Pt-doped Pb-Ru pyrochlore in high area form. Well-crystallized Pb(2)Ru(2)O(7-y) was used to fabricate high performance O2 cathodes with relatively good stability in room temperature KOH. This material was also found to be stable over a useful potential range at approximately 140 C in concentrated KOH. Other pyrochlores were found to be either unstable (amorphous samples) or the fabrication of the gas-fed electrodes could not be fully optimized during this project period. Future work may be directed at this problem. High area platinum supported on conductive metal oxide supports produced mixed results: small improvements in O2 reduction performance for Pb(2)Ru(2)O(7-y) but a large improvement for Li-doped NiO at room temperature. Nearly reversible behavior was observed for the O2/OH couple for Li-doped NiO at approximately 200 C.

  13. Ion pair reinforced semi-interpenetrating polymer network for direct methanol fuel cell applications.

    PubMed

    Fang, Chunliu; Julius, David; Tay, Siok Wei; Hong, Liang; Lee, Jim Yang

    2012-06-01

    This paper describes the synthesis of ion-pair-reinforced semi-interpenetrating polymer networks (SIPNs) as proton exchange membranes (PEMs) for the direct methanol fuel cells (DMFCs). Specifically, sulfonated poly(2,6-dimethyl-1,4-phenylene oxide) (SPPO), a linear polymer proton source, was immobilized in a brominated PPO (BPPO) network covalently cross-linked by ethylenediamine (EDA). The immobilization of SPPO in the SIPN network was accomplished not only by the usual means of mechanical interlocking but also by ion pair formation between the sulfonic acid groups of SPPO and the amine moieties formed during the cross-linking reaction of BPPO with EDA. Through the ion pair interactions, the immobilization of SPPO polymer in the BPPO network was made more effective, resulting in a greater uniformity of sulfonic acid cluster distribution in the membrane. The hydrophilic amine-containing cross-links also compensated for some of the decrease in proton conductivity caused by ion pair formation. The SIPN membranes prepared as such showed good proton conductivity, low methanol permeability, good mechanical properties, and dimensional stability. Consequently, the PPO based SIPN membranes were able to deliver a higher maximum power density than Nafion, demonstrating the potential of the SIPN structure for PEM designs.

  14. Promising alloys for intermediate-temperature solid oxide fuel cell interconnect application

    NASA Astrophysics Data System (ADS)

    Geng, Shujiang; Zhu, Jiahong

    The formation of a low Cr-volatility and electrically conductive oxide outer layer atop an inner chromia layer via thermal oxidation is highly desirable for preventing chromium evaporation from solid oxide fuel cell (SOFC) metallic interconnects at the SOFC operation temperatures. In this paper, a number of ferritic Fe-22Cr alloys with different levels of Mn and Ti as well as a Ni-based alloy Haynes 242 were cyclically oxidized in air at 800 °C for twenty 100-h cycles. No oxide scale spallation was observed during thermal cycling for any of these alloys. A mixed Mn 2O 3/TiO 2 surface layer and/or a (Mn, Cr) 3O 4 spinel outer layer atop a Cr 2O 3 inner layer was formed for the Fe-22Cr series alloys, while an NiO outer layer with a Cr 2O 3 inner layer was developed for Haynes 242 after cyclic oxidation. For the Fe-22Cr series alloys, the effects of Mn and Ti contents as well as alloy purity on the oxidation resistance and scale area specific resistance were evaluated. The performance of the ferritic alloys was compared with that of Haynes 242. The mismatch in thermal expansion coefficient between the different layers in the oxide scale was identified as a potential concern for these otherwise promising alloys.

  15. Study of Pt catalyst on graphene and its application to fuel cell

    NASA Astrophysics Data System (ADS)

    Hsieh, S. H.; Hsu, M. C.; Liu, W. L.; Chen, W. J.

    2013-07-01

    In this work Pt nanoparticles on graphene (PtNPs/GN) were formed from graphite oxide by two routes (one-step and two-step routes). For one-step route, a fixed weight of graphene oxide (GO) and a variable weight of H2PtCl6·6H2O were put in ethylene glycol for a reflux at 120 and 150 °C for 3, 6, 12 and 24 h, respectively. For the two-step route, the first step is reduction of GO films by sodium tetrahydridoborate to obtain graphene. Then, the graphene deposited with Pt particles was put in ethylene glycol for a reflux at 120, 150 and 180 °C for 3, 6, 12 and 24 h. The results show that the electrode catalyst Pt particles have a smaller size and a better distribution on the surface of graphene under the following reducing condition: two-step reduction, reaction time of 12 h, reaction temperature of 150 °C and the 1 g/L of H2PtCl6. These PtNPs/GN composites exhibit superior electrochemically active surface area and high poison tolerance toward methanol oxidation compared to Vulcan XC-72-Pt with the same Pt content. This revealed that the PtNPs/GN can be used as promising electrocatalyst support for direct methanol fuel cells.

  16. Life cycle assessment of gas atomised sponge nickel for use in alkaline hydrogen fuel cell applications

    NASA Astrophysics Data System (ADS)

    Wilson, Benjamin P.; Lavery, Nicholas P.; Jarvis, David J.; Anttila, Tomi; Rantanen, Jyri; Brown, Stephen G. R.; Adkins, Nicholas J.

    2013-12-01

    This paper presents a cradle-to-grave comparative Life Cycle Assessment (LCA) of new gas atomised (GA) sponge nickel catalysts and evaluates their performance against the both cast and crush (CC) sponge nickel and platinum standards currently used in commercial alkaline fuel cells (AFC). The LCA takes into account the energy used and emissions throughout the entire life cycle of sponge nickel catalysts - ranging from the upstream production of materials (mainly aluminium and nickel), to the manufacturing, to the operation and finally to the recycling and disposal. Through this assessment it was found that the energy and emissions during the operational phase associated with a given catalyst considerably outweigh the primary production, manufacturing and recycling. Primary production of the nickel (and to a lesser extent dopant materials) also has a significant environmental impact but this is offset by operational energy savings over the electrode's estimated lifetime and end of life recyclability. From the results it can be concluded that higher activity spongy nickel catalysts produced by gas atomisation could have a significantly lower environmental impact than either CC nickel or platinum. Doped GA sponge nickel in particular showed comparable performance to that of the standard platinum electrode used in AFCs.

  17. Promising aquivion composite membranes based on fluoroalkyl zirconium phosphate for fuel cell applications.

    PubMed

    Donnadio, Anna; Pica, Monica; Subianto, Surya; Jones, Deborah J; Cojocaru, Paula; Casciola, Mario

    2014-08-01

    Layered zirconium phosphate (ZP) that bears fluorinated alkyl chains bonded covalently to the layers (ZPR) was used as a nanofiller in membranes based on a short-side-chain perfluorosulfonic acid (PFSA) to mechanically reinforce the PFSA hydrophobic component. Compared to the pristine PFSA, membranes with a ZPR loading up to 30 wt% show enhanced mechanical properties, and the largest improvement of elastic modulus (E) and yield stress (σY ) are observed for the 10 wt% ZPR membrane: ΔE/E up to 90% and ΔσY /σY up 70% at 70°C and 80% relative humidity (RH). In the RH range 50-95%, the in-plane conductivity of the composite membranes reaches 0.43 S cm(-1) for 10 wt% ZPR at 110°C and is on average 30% higher than the conductivity of the pristine PFSA. The 10 wt % ZPR membrane is as hydrated as the neat PFSA membrane at 50% RH but becomes progressively less hydrated with increasing RH both at 80 and 110°C. The fuel cell performance of this membrane, at 80°C and 30% RH, is better than that of the unmodified PFSA.

  18. Electrocatalysis for oxygen electrodes in fuel cells and water electrolyzers for space applications

    NASA Technical Reports Server (NTRS)

    Prakash, Jai; Tryk, Donald; Yeager, Ernest

    1989-01-01

    In most instances separate electrocatalysts are needed to promote the reduction of O2 in the fuel cell mode and to generate O2 in the energy storage-water electrolysis mode in aqueous electrochemical systems operating at low and moderate temperatures (T greater than or equal to 200 C). Interesting exceptions are the lead and bismuth ruthenate pyrochlores in alkaline electrolytes. These catalysts on high area carbon supports have high catalytic activity for both O2 reduction and generation. Rotating ring-disk electrode measurements provide evidence that the O2 reduction proceeds by a parallel four-electron pathway. The ruthenates can also be used as self-supported catalysts to avoid the problems associated with carbon oxidation, but the electrode performance so far achieved in the research at Case Western Reserve University (CWRU) is considerably less. At the potentials involved in the anodic mode the ruthenate pyrochlores have substantial equilibrium solubility in concentrated alkaline electrolyte. This results in the loss of catalyst into the bulk solution and a decline in catalytic activity. Furthermore, the hydrogen generation counter electrode may become contaminated with reduction products from the pyrochlores (lead, ruthenium).

  19. Microbial fuel cells demonstrate high coulombic efficiency applicable for water remediation.

    PubMed

    Devasahayam, Mercy; Masih, Sam A

    2012-06-01

    Microbial fuel cells (MFCs) convert biomass into electricity by the metabolic activity of microorganisms and are also used for remediation and water treatment. Power output was compared for a dual chambered membrane MFC using either E. coli or two Yamuna river samples, Yamuna (before the Sangam region)--slow flow (sample 1) and Sangam region--fast flow (sample 2). E. coli and the two river water samples 1 and 2 gave a maximum voltage of 779, 463 and 415 mV respectively. Using E. coli the maximum power density obtained with a 100 omega resistor was 220.66 mW/cm2 and the highest power generated 6068.41 mW. The results demonstrate E. coli, river sample 1 and river sample 2 have a comparable coulombic efficiency of 85.2, 71 and 77% respectively when using 0.4% sucrose as substrate. The decrease in chemical oxidative demand of all river water samples using MFC technology demonstrates efficient remediation of inland water.

  20. Carbonate fuel cell anodes

    DOEpatents

    Donado, R.A.; Hrdina, K.E.; Remick, R.J.

    1993-04-27

    A molten alkali metal carbonates fuel cell porous anode of lithium ferrite and a metal or metal alloy of nickel, cobalt, nickel/iron, cobalt/iron, nickel/iron/aluminum, cobalt/iron/aluminum and mixtures thereof wherein the total iron content including ferrite and iron of the composite is about 25 to about 80 percent, based upon the total anode, provided aluminum when present is less than about 5 weight percent of the anode. A process is described for production of the lithium ferrite containing anode by slipcasting.

  1. Carbonate fuel cell anodes

    DOEpatents

    Donado, Rafael A.; Hrdina, Kenneth E.; Remick, Robert J.

    1993-01-01

    A molten alkali metal carbonates fuel cell porous anode of lithium ferrite and a metal or metal alloy of nickel, cobalt, nickel/iron, cobalt/iron, nickel/iron/aluminum, cobalt/iron/aluminum and mixtures thereof wherein the total iron content including ferrite and iron of the composite is about 25 to about 80 percent, based upon the total anode, provided aluminum when present is less than about 5 weight percent of the anode. A process for production of the lithium ferrite containing anode by slipcasting.

  2. Fuel cell having electrolyte

    DOEpatents

    Wright, Maynard K.

    1989-01-01

    A fuel cell having an electrolyte control volume includes a pair of porous opposed electrodes. A maxtrix is positioned between the pair of electrodes for containing an electrolyte. A first layer of backing paper is positioned adjacent to one of the electrodes. A portion of the paper is substantially previous to the acceptance of the electrolyte so as to absorb electrolyte when there is an excess in the matrix and to desorb electrolyte when there is a shortage in the matrix. A second layer of backing paper is positioned adjacent to the first layer of paper and is substantially impervious to the acceptance of electrolyte.

  3. Poly(cyclohexadiene)-Based Polymer Electrolyte Membranes for Fuel Cell Applications

    SciTech Connect

    Mays, Jimmy W.

    2011-03-07

    The goal of this research project was to create and develop fuel cell membranes having high proton conductivity at high temperatures and high chemical and mechanical durability. Poly(1,3-cyclohexadiene) (PCHD) is of interest as an alternative polymer electrolyte membrane (PEM) material due to its ring-like structure which is expected to impart superior mechanical and thermal properties, and due to the fact that PCHD can readily be incorporated into a range of homopolymer and copolymer structures. PCHD can be aromatized, sulfonated, or fluorinated, allowing for tuning of key performance structure and properties. These factors include good proton transport, hydrophilicity, permeability (including fuel gas impermeability), good mechanical properties, morphology, thermal stability, crystallinity, and cost. The basic building block, 1,3-cyclohexadiene, is a hydrocarbon monomer that could be inexpensively produced on a commercial scale (pricing typical of other hydrocarbon monomers). Optimal material properties will result in novel low cost PEM membranes engineered for high conductivity at elevated temperatures and low relative humidities, as well as good performance and durability. The primary objectives of this project were: (1) To design, synthesize and characterize new non-Nafion PEM materials that conduct protons at low (25-50%) RH and at temperatures ranging from room temperature to 120 C; and (2) To achieve these objectives, a range of homopolymer and copolymer materials incorporating poly(cyclohexadiene) (PCHD) will be synthesized, derivatized, and characterized. These two objectives have been achieved. Sulfonated and crosslinked PCHD homopolymer membranes exhibit proton conductivities similar to Nafion in the mid-RH range, are superior to Nafion at higher RH, but are poorer than Nafion at RH < 50%. Thus to further improve proton conductivity, particularly at low RH, poly(ethylene glycol) (PEG) was incorporated into the membrane by blending and by

  4. MOLTEN CARBONATE FUEL CELL PRODUCT DESIGN IMPROVEMENT

    SciTech Connect

    H.C. Maru; M. Farooque

    2004-08-01

    The ongoing program is designed to advance the carbonate fuel cell technology from full-size proof-of-concept field test to the commercial design. DOE has been funding Direct FuelCell{reg_sign} (DFC{reg_sign}) development at FuelCell Energy, Inc. (FCE) for stationary power plant applications. The program efforts are focused on technology and system optimization for cost reduction, leading to commercial design development and prototype system field trials. FCE, Danbury, CT, is a world-recognized leader for the development and commercialization of high efficiency fuel cells that can generate clean electricity at power stations, or at distributed locations near the customers such as hospitals, schools, universities, hotels and other commercial and industrial applications. FCE has designed three different fuel cell power plant models (DFC300A, DFC1500 and DFC3000). FCE's power plants are based on its patented DFC{reg_sign} technology, where the fuel is directly fed to the fuel cell and hydrogen is generated internally. These power plants offer significant advantages compared to the existing power generation technologies--higher fuel efficiency, significantly lower emissions, quieter operation, flexible siting and permitting requirements, scalability and potentially lower operating costs. Also, the exhaust heat by-product can be used for cogeneration applications such as high-pressure steam, district heating and air conditioning. Several FCE sub-megawatt power plants are currently operating in Europe, Japan and the US. Because hydrogen is generated directly within the fuel cell module from readily available fuels such as natural gas and waste water treatment gas, DFC power plants are ready today and do not require the creation of a hydrogen infrastructure. Product improvement progress made during the reporting period in the areas of technology, manufacturing processes, cost reduction and balance of plant equipment designs is discussed in this report.

  5. Unitized regenerative fuel cell system

    NASA Technical Reports Server (NTRS)

    Burke, Kenneth A. (Inventor)

    2008-01-01

    A Unitized Regenerative Fuel Cell system uses heat pipes to convey waste heat from the fuel cell stack to the reactant storage tanks. The storage tanks act as heat sinks/sources and as passive radiators of the waste heat from the fuel cell stack. During charge up, i.e., the electrolytic process, gases are conveyed to the reactant storage tanks by way of tubes that include dryers. Reactant gases moving through the dryers give up energy to the cold tanks, causing water vapor in with the gases to condense and freeze on the internal surfaces of the dryer. During operation in its fuel cell mode, the heat pipes convey waste heat from the fuel cell stack to the respective reactant storage tanks, thereby heating them such that the reactant gases, as they pass though the respective dryers on their way to the fuel cell stacks retrieve the water previously removed.

  6. Hybrid Fuel Cell Technology Overview

    SciTech Connect

    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.

  7. Selective enrichment of electrogenic bacteria for fuel cell application: Enumerating microbial dynamics using MiSeq platform.

    PubMed

    Vamshi Krishna, K; Venkata Mohan, S

    2016-08-01

    This study is intended to examine the effect of pretreatment on selective enrichment of electrogenic bacteria from mixed culture. It has been observed that the iodopropane and heat-shock pretreatments suppress the growth of non-exoelectrons, while selecting only a limited number of strains belonging to genera Xanthomonas, Pseudomonas and Prevotella while untreated control inoculum showed more diverse community comprising of both exoelectrogens and non-exoelectrogens. High power output was observed in iodopropane (180mW/m(2)) pretreated microbial fuel cell (MFC) compared to heat-shock pretreated MFC (128mW/m(2)) and untreated control (92mW/m(2)). Coulombic efficiency of iodopropane and heat-shock pretreated MFC was higher compared to untreated control MFC, while drop in pH and volatile fatty acids (VFA) production was less in iodopropane pretreated MFC signifying the shifts in bacterial community structure toward electrogenesis instead of fermentation. These results signify the role of iodopropane and heat pretreatments on enrichment of electrogenic bacteria for fuel cell application. PMID:27061058

  8. DOE perspective on fuel cells in transportation

    SciTech Connect

    Kost, R.

    1996-04-01

    Fuel cells are one of the most promising technologies for meeting the rapidly growing demand for transportation services while minimizing adverse energy and environmental impacts. This paper reviews the benefits of introducing fuel cells into the transportation sector; in addition to dramatically reduced vehicle emissions, fuel cells offer the flexibility than use petroleum-based or alternative fuels, have significantly greater energy efficiency than internal combustion engines, and greatly reduce noise levels during operation. The rationale leading to the emphasis on proton-exchange-membrane fuel cells for transportation applications is reviewed as are the development issues requiring resolution to achieve adequate performance, packaging, and cost for use in automobiles. Technical targets for power density, specific power, platinum loading on the electrodes, cost, and other factors that become increasingly more demanding over time have been established. Fuel choice issues and pathways to reduced costs and to a renewable energy future are explored. One such path initially introduces fuel cell vehicles using reformed gasoline while-on-board hydrogen storage technology is developed to the point of allowing adequate range (350 miles) and refueling convenience. This scenario also allows time for renewable hydrogen production technologies and the required supply infrastructure to develop. Finally, the DOE Fuel Cells in Transportation program is described. The program, whose goal is to establish the technology for fuel cell vehicles as rapidly as possible, is being implemented by means of the United States Fuel Cell Alliance, a Government-industry alliance that includes Detroit`s Big Three automakers, fuel cell and other component suppliers, the national laboratories, and universities.

  9. Improved electrolytes for fuel cells

    SciTech Connect

    Gard, G.L.; Roe, D.K.

    1991-06-01

    Present day fuel cells based upon hydrogen and oxygen have limited performance due to the use of phosphoric acid as an electrolyte. Improved performance is desirable in electrolyte conductivity, electrolyte management, oxygen solubility, and the kinetics of the reduction of oxygen. Attention has turned to fluorosulfonic acids as additives or substitute electrolytes to improve fuel cell performance. The purpose of this project is to synthesize and electrochemically evaluate new fluorosulfonic acids as superior alternatives to phosphoric acid in fuel cells. (VC)

  10. Fuel cell design and assembly

    NASA Technical Reports Server (NTRS)

    Myerhoff, Alfred (Inventor)

    1984-01-01

    The present invention is directed to a novel bipolar cooling plate, fuel cell design and method of assembly of fuel cells. The bipolar cooling plate used in the fuel cell design and method of assembly has discrete opposite edge and means carried by the plate defining a plurality of channels extending along the surface of the plate toward the opposite edges. At least one edge of the channels terminates short of the edge of the plate defining a recess for receiving a fastener.

  11. Fuel cell gas management system

    DOEpatents

    DuBose, Ronald Arthur

    2000-01-11

    A fuel cell gas management system including a cathode humidification system for transferring latent and sensible heat from an exhaust stream to the cathode inlet stream of the fuel cell; an anode humidity retention system for maintaining the total enthalpy of the anode stream exiting the fuel cell equal to the total enthalpy of the anode inlet stream; and a cooling water management system having segregated deionized water and cooling water loops interconnected by means of a brazed plate heat exchanger.

  12. The direct methanol fuel cell

    SciTech Connect

    Halpert, G.; Narayanan, S.R.; Frank, H.

    1995-08-01

    This presentation describes the approach and progress in the ARPA-sponsored effort to develop a Direct Methanol, Liquid-Feed Fuel Cell (DMLFFC) with a solid Polymer Electrolyte Membrane (PEM) for battery replacement in small portable applications. Using Membrane Electrode Assemblies (MEAs) developed by JPL and Giner, significant voltage was demonstrated at relatively high current densities. The DMLFFC utilizes a 3 percent aqueous solution of methanol that is oxidized directly in the anode (fuel) chamber and oxygen (air) in the cathode chamber to produce water and significant power. The only products are water and CO{sub 2}. The ARPA effort is aimed at replacing the battery in the BA 5590 military radio.

  13. Plasma membranes modified by plasma treatment or deposition as solid electrolytes for potential application in solid alkaline fuel cells.

    PubMed

    Reinholdt, Marc; Ilie, Alina; Roualdès, Stéphanie; Frugier, Jérémy; Schieda, Mauricio; Coutanceau, Christophe; Martemianov, Serguei; Flaud, Valérie; Beche, Eric; Durand, Jean

    2012-07-30

    In the highly competitive market of fuel cells, solid alkaline fuel cells using liquid fuel (such as cheap, non-toxic and non-valorized glycerol) and not requiring noble metal as catalyst seem quite promising. One of the main hurdles for emergence of such a technology is the development of a hydroxide-conducting membrane characterized by both high conductivity and low fuel permeability. Plasma treatments can enable to positively tune the main fuel cell membrane requirements. In this work, commercial ADP-Morgane® fluorinated polymer membranes and a new brand of cross-linked poly(aryl-ether) polymer membranes, named AMELI-32®, both containing quaternary ammonium functionalities, have been modified by argon plasma treatment or triallylamine-based plasma deposit. Under the concomitant etching/cross-linking/oxidation effects inherent to the plasma modification, transport properties (ionic exchange capacity, water uptake, ionic conductivity and fuel retention) of membranes have been improved. Consequently, using plasma modified ADP-Morgane® membrane as electrolyte in a solid alkaline fuel cell operating with glycerol as fuel has allowed increasing the maximum power density by a factor 3 when compared to the untreated membrane.

  14. Plasma Membranes Modified by Plasma Treatment or Deposition as Solid Electrolytes for Potential Application in Solid Alkaline Fuel Cells

    PubMed Central

    Reinholdt, Marc; Ilie, Alina; Roualdès, Stéphanie; Frugier, Jérémy; Schieda, Mauricio; Coutanceau, Christophe; Martemianov, Serguei; Flaud, Valérie; Beche, Eric; Durand, Jean

    2012-01-01

    In the highly competitive market of fuel cells, solid alkaline fuel cells using liquid fuel (such as cheap, non-toxic and non-valorized glycerol) and not requiring noble metal as catalyst seem quite promising. One of the main hurdles for emergence of such a technology is the development of a hydroxide-conducting membrane characterized by both high conductivity and low fuel permeability. Plasma treatments can enable to positively tune the main fuel cell membrane requirements. In this work, commercial ADP-Morgane® fluorinated polymer membranes and a new brand of cross-linked poly(aryl-ether) polymer membranes, named AMELI-32®, both containing quaternary ammonium functionalities, have been modified by argon plasma treatment or triallylamine-based plasma deposit. Under the concomitant etching/cross-linking/oxidation effects inherent to the plasma modification, transport properties (ionic exchange capacity, water uptake, ionic conductivity and fuel retention) of membranes have been improved. Consequently, using plasma modified ADP-Morgane® membrane as electrolyte in a solid alkaline fuel cell operating with glycerol as fuel has allowed increasing the maximum power density by a factor 3 when compared to the untreated membrane. PMID:24958295

  15. Plasma membranes modified by plasma treatment or deposition as solid electrolytes for potential application in solid alkaline fuel cells.

    PubMed

    Reinholdt, Marc; Ilie, Alina; Roualdès, Stéphanie; Frugier, Jérémy; Schieda, Mauricio; Coutanceau, Christophe; Martemianov, Serguei; Flaud, Valérie; Beche, Eric; Durand, Jean

    2012-01-01

    In the highly competitive market of fuel cells, solid alkaline fuel cells using liquid fuel (such as cheap, non-toxic and non-valorized glycerol) and not requiring noble metal as catalyst seem quite promising. One of the main hurdles for emergence of such a technology is the development of a hydroxide-conducting membrane characterized by both high conductivity and low fuel permeability. Plasma treatments can enable to positively tune the main fuel cell membrane requirements. In this work, commercial ADP-Morgane® fluorinated polymer membranes and a new brand of cross-linked poly(aryl-ether) polymer membranes, named AMELI-32®, both containing quaternary ammonium functionalities, have been modified by argon plasma treatment or triallylamine-based plasma deposit. Under the concomitant etching/cross-linking/oxidation effects inherent to the plasma modification, transport properties (ionic exchange capacity, water uptake, ionic conductivity and fuel retention) of membranes have been improved. Consequently, using plasma modified ADP-Morgane® membrane as electrolyte in a solid alkaline fuel cell operating with glycerol as fuel has allowed increasing the maximum power density by a factor 3 when compared to the untreated membrane. PMID:24958295

  16. CLIMATE CHANGE FUEL CELL PROGRAM

    SciTech Connect

    Steven A. Gabrielle

    2004-12-03

    This report discusses the first year of operation of a fuel cell power plant located at the Sheraton Edison Hotel, Edison, New Jersey. PPL EnergyPlus, LLC installed the plant under a contract with the Starwood Hotels & Resorts Worldwide, Inc. A DFC{reg_sign}300 fuel cell, manufactured by FuelCell Energy, Inc. of Danbury, CT was selected for the project. The fuel cell successfully operated from June 2003 to May 2004. This report discusses the performance of the plant during this period.

  17. Orbiter fuel cell improvement assessment

    NASA Technical Reports Server (NTRS)

    Johnson, R. E.

    1981-01-01

    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.

  18. Molten carbonate fuel cell separator

    DOEpatents

    Nickols, R.C.

    1984-10-17

    In a stacked array of molten carbonate fuel cells, a fuel cell separator is positioned between adjacent fuel cells to provide isolation as well as a conductive path therebetween. The center portion of the fuel cell separator includes a generally rectangular, flat, electrical conductor. Around the periphery of the flat portion of the separator are positioned a plurality of elongated resilient flanges which form a gas-tight seal around the edges of the fuel cell. With one elongated flange resiliently engaging a respective edge of the center portion of the separator, the sealing flanges, which are preferably comprised of a noncorrosive material such as an alloy of yttrium, iron, aluminum or chromium, form a tight-fitting wet seal for confining the corrosive elements of the fuel cell therein. This arrangement permits a good conductive material which may be highly subject to corrosion and dissolution to be used in combination with a corrosion-resistant material in the fuel cell separator of a molten carbonate fuel cell for improved fuel cell conductivity and a gas-tight wet seal.

  19. Molten carbonate fuel cell separator

    DOEpatents

    Nickols, Richard C.

    1986-09-02

    In a stacked array of molten carbonate fuel cells, a fuel cell separator is positioned between adjacent fuel cells to provide isolation as well as a conductive path therebetween. The center portion of the fuel cell separator includes a generally rectangular, flat, electrical conductor. Around the periphery of the flat portion of the separator are positioned a plurality of elongated resilient flanges which form a gas-tight seal around the edges of the fuel cell. With one elongated flange resiliently engaging a respective edge of the center portion of the separator, the sealing flanges, which are preferably comprised of a noncorrosive material such as an alloy of yttrium, iron, aluminum or chromium, form a tight-fitting wet seal for confining the corrosive elements of the fuel cell therein. This arrangement permits a good conductive material which may be highly subject to corrosion and dissolution to be used in combination with a corrosion-resistant material in the fuel cell separator of a molten carbonate fuel cell for improved fuel cell conductivity and a gas-tight wet seal.

  20. Electrocatalysts for oxygen electrodes in fuel cells and water electrolyzers for space applications

    NASA Astrophysics Data System (ADS)

    Prakash, Jai; Tryk, Donald; Yeager, Ernest

    1989-12-01

    In most instances separate electrocatalysts are needed to promote the reduction of O2 in the fuel cell mode and to generate O2 in the energy storage-water electrolysis mode in aqueous electrochemical systems operating at low and moderate temperatures (T greater than or equal to 200 C). Interesting exceptions are the lead and bismuth ruthenate pyrochlores in alkaline electrolytes. These catalysts on high area carbon supports have high catalytic activity for both O2 reduction and generation (1,2). Rotating ring-disk electrode measurements provide evidence that the O2 reduction proceeds by a parallel four-electron pathway. The ruthenates can also be used as self-supported catalysts to avoid the problems associated with carbon oxidation, but the electrode performance so far achieved in the research at Case Western Reserve University (CWRU) is considerably less. At the potentials involved in the anodic mode the ruthenate pyrochlores have substantial equilibrium solubility in concentrated alkaline electrolyte. This results in the loss of catalyst into the bulk solution and a decline in catalytic activity. Furthermore, the hydrogen generation counter electrode may become contaminated with reduction products from the pyrochlores (lead, ruthenium). A possible approach to this problem is to immobilize the pyrochlore catalyst within an ionic-conducting solid polymer, which would replace the fluid electrolyte within the porous gas diffusion O2 electrode. For bulk alkaline electrolyte, an anion-exchange polymer is needed with a transference number close to unity for the Oh(-) ion. Preliminary short-term measurements with lead ruthenates using a commercially available partially-fluorinated anion-exchange membrane as an overlayer on the porous gas-fed electrode indicate lower anodic polarization and virtually unchanged cathodic polarization.

  1. Electrocatalysts for oxygen electrodes in fuel cells and water electrolyzers for space applications

    NASA Technical Reports Server (NTRS)

    Prakash, Jai; Tryk, Donald; Yeager, Ernest

    1989-01-01

    In most instances separate electrocatalysts are needed to promote the reduction of O2 in the fuel cell mode and to generate O2 in the energy storage-water electrolysis mode in aqueous electrochemical systems operating at low and moderate temperatures (T greater than or equal to 200 C). Interesting exceptions are the lead and bismuth ruthenate pyrochlores in alkaline electrolytes. These catalysts on high area carbon supports have high catalytic activity for both O2 reduction and generation (1,2). Rotating ring-disk electrode measurements provide evidence that the O2 reduction proceeds by a parallel four-electron pathway. The ruthenates can also be used as self-supported catalysts to avoid the problems associated with carbon oxidation, but the electrode performance so far achieved in the research at Case Western Reserve University (CWRU) is considerably less. At the potentials involved in the anodic mode the ruthenate pyrochlores have substantial equilibrium solubility in concentrated alkaline electrolyte. This results in the loss of catalyst into the bulk solution and a decline in catalytic activity. Furthermore, the hydrogen generation counter electrode may become contaminated with reduction products from the pyrochlores (lead, ruthenium). A possible approach to this problem is to immobilize the pyrochlore catalyst within an ionic-conducting solid polymer, which would replace the fluid electrolyte within the porous gas diffusion O2 electrode. For bulk alkaline electrolyte, an anion-exchange polymer is needed with a transference number close to unity for the Oh(-) ion. Preliminary short-term measurements with lead ruthenates using a commercially available partially-fluorinated anion-exchange membrane as an overlayer on the porous gas-fed electrode indicate lower anodic polarization and virtually unchanged cathodic polarization.

  2. EFFECT OF FUEL IMPURITIES ON FUEL CELL PERFORMANCE AND DURABILITY

    SciTech Connect

    Colon-Mercado, H.

    2010-09-28

    A fuel cell is an electrochemical energy conversion device that produces electricity during the combination of hydrogen and oxygen to produce water. Proton exchange membranes fuel cells are favored for portable applications as well as stationary ones due to their high power density, low operating temperature, and low corrosion of components. In real life operation, the use of pure fuel and oxidant gases results in an impractical system. A more realistic and cost efficient approach is the use of air as an oxidant gas and hydrogen from hydrogen carriers (i.e., ammonia, hydrocarbons, hydrides). However, trace impurities arising from different hydrogen sources and production increases the degradation of the fuel cell. These impurities include carbon monoxide, ammonia, sulfur, hydrocarbons, and halogen compounds. The International Organization for Standardization (ISO) has set maximum limits for trace impurities in the hydrogen stream; however fuel cell data is needed to validate the assumption that at those levels the impurities will cause no degradation. This report summarizes the effect of selected contaminants tested at SRNL at ISO levels. Runs at ISO proposed concentration levels show that model hydrocarbon compound such as tetrahydrofuran can cause serious degradation. However, the degradation is only temporary as when the impurity is removed from the hydrogen stream the performance completely recovers. Other molecules at the ISO concentration levels such as ammonia don't show effects on the fuel cell performance. On the other hand carbon monoxide and perchloroethylene shows major degradation and the system can only be recovered by following recovery procedures.

  3. Monolithic solid oxide fuel cell development

    NASA Technical Reports Server (NTRS)

    Myles, K. M.; Mcpheeters, C. C.

    1989-01-01

    The feasibility of the monolithic solid oxide fuel cell (MSOFC) concept has been proven, and the performance has been dramatically improved. The differences in thermal expansion coefficients and firing shrinkages among the fuel cell materials have been minimized, thus allowing successful fabrication of the MSOFC with few defects. The MSOFC shows excellent promise for development into a practical power source for many applications from stationary power, to automobile propulsion, to space pulsed power.

  4. Catalysts for ultrahigh current density oxygen cathodes for space fuel cell applications

    NASA Technical Reports Server (NTRS)

    Tryk, Donald A.; Yeager, E.

    1992-01-01

    The objective was to identify promising electrocatalyst/support systems for oxygen cathodes capable of operating at ultrahigh current densities in alkaline fuel cells. Such cells will require operation at relatively high temperatures and O2 pressures. A number of materials were prepared, including Pb-Ru and Pb-Ir pyrochlores, RuO2 and Pt-doped RuO2, lithiated NiO and La-Ni perovskites. Several of these materials were prepared using techniques that had not been previously used to prepare them. Particularly interesting was the use of the alkaline solution technique to prepare Pt-doped and Pb-Ru pyrochlores in high area form. Also interesting was the use of the fusion (melt) method for preparing the Pb-Ru pyrochlore. Several of the materials were also deposited with platinum. Well-crystallized Pb2Ru2O(7-y) was used to fabricate very high performance O2 cathodes with good stability in room temperature KOH. This material was also found to be stable over a useful potential range at approx. 140 C in concentrated KOH. For some of the samples, fabrication of the gas-fed electrodes could not be fully optimized during this project period. Future work may be directed at this problem. Pyrochlores that were not well-crystallized were found to be unstable in alkaline solution. Very good O2 reduction performance and stability were observed with Pb2RuO(7-y) in a carbon-based gas-fed electrode with an anion-conducting membrane placed on the electrolyte side of the electrode. The performance came within a factor of about two of that observed without carbon. High area platinum and gold supported on several conductive metal oxide supports were examined. Only small improvements in O2 reduction performance at room temperature were observed for Pb2Ru2O(7-y) as a support because of the high intrinsic activity of the pyrochlore. In contrast, a large improvement was observed for Li-doped NiO as a support for Pt. Very poor performance was observed for Au deposited on Li-NiO at approx. 150 C

  5. Solid oxide MEMS-based fuel cells

    DOEpatents

    Jankowksi, Alan F.; Morse, Jeffrey D.

    2007-03-13

    A micro-electro-mechanical systems (MEMS) based thin-film fuel cells for electrical power applications. The MEMS-based fuel cell may be of a solid oxide type (SOFC), a solid polymer type (SPFC), or a proton exchange membrane type (PEMFC), and each fuel cell basically consists of an anode and a cathode separated by an electrolyte layer. The electrolyte layer can consist of either a solid oxide or solid polymer material, or proton exchange membrane electrolyte materials may be used. Additionally catalyst layers can also separate the electrodes (cathode and anode) from the electrolyte. Gas manifolds are utilized to transport the fuel and oxidant to each cell and provide a path for exhaust gases. The electrical current generated from each cell is drawn away with an interconnect and support structure integrated with the gas manifold. The fuel cells utilize integrated resistive heaters for efficient heating of the materials. By combining MEMS technology with thin-film deposition technology, thin-film fuel cells having microflow channels and full-integrated circuitry can be produced that will lower the operating temperature an will yield an order of magnitude greater power density than the currently known fuel cells.

  6. Solid polymer MEMS-based fuel cells

    DOEpatents

    Jankowski, Alan F.; Morse, Jeffrey D.

    2008-04-22

    A micro-electro-mechanical systems (MEMS) based thin-film fuel cells for electrical power applications. The MEMS-based fuel cell may be of a solid oxide type (SOFC), a solid polymer type (SPFC), or a proton exchange membrane type (PEMFC), and each fuel cell basically consists of an anode and a cathode separated by an electrolyte layer. The electrolyte layer can consist of either a solid oxide or solid polymer material, or proton exchange membrane electrolyte materials may be used. Additionally catalyst layers can also separate the electrodes (cathode and anode) from the electrolyte. Gas manifolds are utilized to transport the fuel and oxidant to each cell and provide a path for exhaust gases. The electrical current generated from each cell is drawn away with an interconnect and support structure integrated with the gas manifold. The fuel cells utilize integrated resistive heaters for efficient heating of the materials. By combining MEMS technology with thin-film deposition technology, thin-film fuel cells having microflow channels and full-integrated circuitry can be produced that will lower the operating temperature an will yield an order of magnitude greater power density than the currently known fuel cells.

  7. Fuel Cell Powered Lift Truck

    SciTech Connect

    Moulden, Steve

    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.

  8. Unitized regenerative fuel cell systems

    SciTech Connect

    Mitlitsky, F; Molter, T M; Myers, B; Weisberg, A H

    1998-09-10

    Energy storage systems with extremely high specific energy (>400 Wh/kg) have been designed that use lightweight pressure vessels to contain the gases generated by reversible (unitized) regenerative fuel cells (URFCs).[1] URFC systems are being designed and developed for a variety of applications, including high altitude long endurance (HALE) solar rechargeable aircraft (SRA), zero emission vehicles (ZEVs), hybrid energy storage/propulsion systems for spacecraft, energy storage for remote (off-grid) power sources, and peak shaving for on-grid applications.[1-10] Energy storage for HALE SRA was the original application for this set of innovations, and a prototype solar powered aircraft (Pathfinder-Plus) recently set another altitude record for all propeller-driven aircraft on August 6, 1998, when it flew to 80,285 feet (24.47 km).[11

  9. [Progress of research on the microbial fuel cells in the application of environment pollution treatment--a review].

    PubMed

    Yang, Yonggang; Sun, Guoping; Xu, Meiying

    2010-07-01

    Microbial fuel cells (MFCs) are bio-electrochemical reactors that have the capacity to convert chemical energy of biodegradable organic chemicals to electrical energy, and developed rapidly in the past few years. With an increasing concern for energy crisis and environment pollution, MFCs has became a promising technology in the researches of environment pollution treatments and biology electricity. In this paper, we offered a comprehensive review of the recent research progress of MFCs in environment pollution treatment, includes denitrification, desufurization, organic pollutants degradation, heavy metal reduction and landfill leachate treatment. Also, we pointed out the challenges and problems which were bottle necks for a wide application of MFCs and the potential future development. PMID:20815229

  10. Cross-linked polyelectrolyte for direct methanol fuel cells applications based on a novel sulfonated cross-linker

    NASA Astrophysics Data System (ADS)

    Li, Mingyu; Zhang, Gang; Xu, Shuai; Zhao, Chengji; Han, Miaomiao; Zhang, Liyuan; Jiang, Hao; Liu, Zhongguo; Na, Hui

    2014-06-01

    A novel type of cross-linked proton exchange membrane of lower methanol permeation and high proton conductivity is prepared, based on a newly synthesized sulfonated cross-linker: carboxyl terminated benzimidazole trimer bearing sulfonic acid groups (s-BI). Compared to membranes cross-linked with non-sulfonated cross-linker (BI), SPEEK/s-BI-n membranes show higher IEC values and proton conductivities. Meanwhile, oxidative stability and mechanical property of SPEEK/s-BI-n membranes are obviously improved. Among SPEEK/s-BI-n membranes, SPEEK/s-BI-2 exhibits high proton conductivity, low swelling ratio (0.122 S cm-1 and 15.2% at 60 °C, respectively) and low methanol permeability coefficient. These results imply that the cross-linked membranes prepared with the newly sulfonated cross-linker are promising for the direct methanol fuel cells (DMFCs) application.

  11. Morphological features of electrodeposited Pt nanoparticles and its application as anode catalysts in polymer electrolyte formic acid fuel cells

    NASA Astrophysics Data System (ADS)

    Jeon, Hongrae; Joo, Jiyong; Kwon, Youngkook; Uhm, Sunghyun; Lee, Jaeyoung

    Electrodeposited Pt nanoparticles on carbon substrate show various morphologies depending on the applied potentials. Dendritic, pyramidal, cauliflower-like, and hemi-spherical morphologies of Pt are formed at potential ranges between -0.2 and 0.3 V (vs. Ag/AgCl) and its particle sizes are distributed from 8 to 26 nm. Dendritic bulky particles over 20 nm are formed at an applied potential of -0.2 V, while low deposition potential of 0.2 V causes dense hemi-spherical structure of Pt less than 10 nm. The influence of different Pt shapes on an electrocatalytic oxidation of formic acid is represented. Consequently, homogeneous distribution of Pt nanoparticles with average particle of ca. 14 nm on carbon paper results in a high surface to volume ratio and the better power performance in a fuel cell application.

  12. Preparation of Arc Black and Carbon Nano Balloon by Arc Discharge and Their Application to a Fuel Cell

    NASA Astrophysics Data System (ADS)

    Ikeda, Takashi; Kaida, Shota; Satou, Tosiyuki; Suda, Yoshiyuki; Takikawa, Hirofumi; Tanoue, Hideto; Oke, Shinichiro; Ue, Hitoshi; Okawa, Takashi; Aoyagi, Nobuhiro; Shimizu, Kazuki

    2011-01-01

    Arc black (AcB) was prepared in N2 gas using the twin-torch arc discharge apparatus, and a hollow capsule with graphite layers named a carbon nano balloon (CNB) was obtained by heat treatment of the AcB in Ar gas at 2400 °C. Transmission electron microscopy, Raman spectroscopy, thermogravimetric analysis, and compressive resistivity measurement confirmed that the CNB was well graphitized. In the direct methanol fuel cell (DMFC) application of these carbon nanomaterials, catalyst metal nanoparticles were supported on the AcB, and a membrane-electrode assembly (MEA) was formed from the catalyst-supported AcB and the CNB by hotpressing them on an electrolyte film. The MEA containing the CNB resulted in a higher DMFC performance than that without the CNB, indicating that the CNB with lower compressive resistivity than the AcB works as a material for the improvement of electric conductivity in an MEA.

  13. An Interleaved Reduced-Component-Count Multivoltage Bus DC/DC Converter for Fuel Cell Powered Electric Vehicle Applications

    SciTech Connect

    Tang, Lixin; Su, Gui-Jia

    2008-01-01

    An interleaved reduced-component-count dc/dc converter is proposed for power management in fuel cell powered vehicles with a multivoltage electric net. The converter is based on a simplified topology and can handle more power with less ripple current, therefore reducing the capacitor requirements, making it more suited for fuel cell powered vehicles in the near future. A prototype rated at 4.3 kW was built and tested to verify the proposed topology.

  14. Fuel cell development for transportation: Catalyst development

    SciTech Connect

    Doddapaneni, N.; Ingersoll, D.

    1996-12-31

    Fuel cells are being considered as alternative power sources for transportation and stationary applications. The degradation of commonly used electrode catalysts (e.g. Pt, Ag, and others) and corrosion of carbon substrates are making commercialization of fuel cells incorporating present day technologies economically problematic. Furthermore, due to the instability of the Pt catalyst, the performance of fuel cells declines on long-term operation. When methanol is used as the fuel, a voltage drop, as well as significant thermal management problems can be encountered, the later being due to chemical oxidation of methanol at the platinized carbon at the cathode. Though extensive work was conducted on platinized electrodes for both the oxidation and reduction reactions, due to the problems mentioned above, fuel cells have not been fully developed for widespread commercial use. Several investigators have previously evaluated metal macrocyclic complexes as alternative catalysts to Pt and Pt/Ru in fuel cells. Unfortunately, though they have demonstrated catalytic activity, these materials were found to be unstable on long term use in the fuel cell environment. In order to improve the long-term stability of metal macrocyclic complexes, we have chemically bonded these complexes to the carbon substrate, thereby enhancing their catalytic activity as well as their chemical stability in the fuel cell environment. We have designed, synthesized, and evaluated these catalysts for O{sub 2} reduction, H{sub 2} oxidation, and direct methanol oxidation in Proton Exchange Membrane (PEM) and aqueous carbonate fuel cells. These catalysts exhibited good catalytic activity and long-term stability. In this paper we confine our discussion to the initial performance results of some of these catalysts in H{sub 2}/O{sub 2} PEM fuel cells, including their long-term performance characteristics as well as CO poisoning effects on these catalysts.

  15. Syngas suitability for solid oxide fuel cells applications produced via biomass steam gasification process: Experimental and modeling analysis

    NASA Astrophysics Data System (ADS)

    Pieratti, Elisa; Baratieri, Marco; Ceschini, Sergio; Tognana, Lorenzo; Baggio, Paolo

    The technologies and the processes for the use of biomass as an energy source are not always environmental friendly. It is worth to develop approaches aimed at a more sustainable exploitation of biomass, avoiding whenever possible direct combustion and rather pursuing fuel upgrade paths, also considering direct conversion to electricity through fuel cells. In this context, it is of particular interest the development of the biomass gasification technology for synthesis gas (i.e., syngas) production, and the utilization of the obtained gas in fuel cells systems, in order to generate energy from renewable resources. Among the different kind of fuel cells, SOFCs (solid oxide fuel cells), which can be fed with different type of fuels, seem to be also suitable for this type of gaseous fuel. In this work, the syngas composition produced by means of a continuous biomass steam gasifier (fixed bed) has been characterized. The hydrogen concentration in the syngas is around 60%. The system is equipped with a catalytic filter for syngas purification and some preliminary tests coupling the system with a SOFCs stack are shown. The data on the syngas composition and temperature profile measured during the experimental activity have been used to calibrate a 2-dimensional thermodynamic equilibrium model.

  16. Fuel cell electric power production

    DOEpatents

    Hwang, Herng-Shinn; Heck, Ronald M.; Yarrington, Robert M.

    1985-01-01

    A process for generating electricity from a fuel cell includes generating a hydrogen-rich gas as the fuel for the fuel cell by treating a hydrocarbon feed, which may be a normally liquid feed, in an autothermal reformer utilizing a first monolithic catalyst zone having palladium and platinum catalytic components therein and a second, platinum group metal steam reforming catalyst. Air is used as the oxidant in the hydrocarbon reforming zone and a low oxygen to carbon ratio is maintained to control the amount of dilution of the hydrogen-rich gas with nitrogen of the air without sustaining an insupportable amount of carbon deposition on the catalyst. Anode vent gas may be utilized as the fuel to preheat the inlet stream to the reformer. The fuel cell and the reformer are preferably operated at elevated pressures, up to about a pressure of 150 psia for the fuel cell.

  17. Solid oxide fuel cell generator

    DOEpatents

    Draper, Robert; George, Raymond A.; Shockling, Larry A.

    1993-01-01

    A solid oxide fuel cell generator has a pair of spaced apart tubesheets in a housing. At least two intermediate barrier walls are between the tubesheets and define a generator chamber between two intermediate buffer chambers. An array of fuel cells have tubes with open ends engaging the tubesheets. Tubular, axially elongated electrochemical cells are supported on the tubes in the generator chamber. Fuel gas and oxidant gas are preheated in the intermediate chambers by the gases flowing on the other side of the tubes. Gas leakage around the tubes through the tubesheets is permitted. The buffer chambers reentrain the leaked fuel gas for reintroduction to the generator chamber.

  18. Solid oxide fuel cell generator

    DOEpatents

    Draper, R.; George, R.A.; Shockling, L.A.

    1993-04-06

    A solid oxide fuel cell generator has a pair of spaced apart tubesheets in a housing. At least two intermediate barrier walls are between the tubesheets and define a generator chamber between two intermediate buffer chambers. An array of fuel cells have tubes with open ends engaging the tubesheets. Tubular, axially elongated electrochemical cells are supported on the tubes in the generator chamber. Fuel gas and oxidant gas are preheated in the intermediate chambers by the gases flowing on the other side of the tubes. Gas leakage around the tubes through the tubesheets is permitted. The buffer chambers reentrain the leaked fuel gas for reintroduction to the generator chamber.

  19. MOLTEN CARBONATE FUEL CELL PRODUCT DESIGN IMPROVEMENT

    SciTech Connect

    H.C. Maru; M. Farooque

    2002-02-01

    The carbonate fuel cell promises highly efficient, cost-effective and environmentally superior power generation from pipeline natural gas, coal gas, biogas, and other gaseous and liquid fuels. FuelCell Energy, Inc. has been engaged in the development of this unique technology, focusing on the development of the Direct Fuel Cell (DFC{reg_sign}). The DFC{reg_sign} design incorporates the unique internal reforming feature which allows utilization of a hydrocarbon fuel directly in the fuel cell without requiring any external reforming reactor and associated heat exchange equipment. This approach upgrades waste heat to chemical energy and thereby contributes to a higher overall conversion efficiency of fuel energy to electricity with low levels of environmental emissions. Among the internal reforming options, FuelCell Energy has selected the Indirect Internal Reforming (IIR)--Direct Internal Reforming (DIR) combination as its baseline design. The IIR-DIR combination allows reforming control (and thus cooling) over the entire cell area. This results in uniform cell temperature. In the IIR-DIR stack, a reforming unit (RU) is placed in between a group of fuel cells. The hydrocarbon fuel is first fed into the RU where it is reformed partially to hydrogen and carbon monoxide fuel using heat produced by the fuel cell electrochemical reactions. The reformed gases are then fed to the DIR chamber, where the residual fuel is reformed simultaneously with the electrochemical fuel cell reactions. FuelCell Energy plans to offer commercial DFC power plants in various sizes, focusing on the subMW as well as the MW-scale units. The plan is to offer standardized, packaged DFC power plants operating on natural gas or other hydrocarbon-containing fuels for commercial sale. The power plant design will include a diesel fuel processing option to allow dual fuel applications. These power plants, which can be shop-fabricated and sited near the user, are ideally suited for distributed power

  20. The role of fuel cells in NASA's space power systems

    NASA Technical Reports Server (NTRS)

    Been, J. F.

    1979-01-01

    The advances in fuel cell technology which have expanded the capabilities of the fuel cell from that of power generation to include energy storage also expanded its potential role in space power systems. This paper presents a brief evolutionary history of the fuel cell technology and compares this with NASA's increasing space power requirements. The role of fuel cells is put in perspective with other energy storage systems applicable for space using such criteria as type of mission, weight, reliability, costs, etc. Potential applications of space fuel cells with projected technology advances are examined.

  1. Titanium dioxide in fuel cell technology: An overview

    NASA Astrophysics Data System (ADS)

    Abdullah, N.; Kamarudin, S. K.

    2015-03-01

    Fuel cell technology is one of the alternative energy sources for the next generation. Although this technology has proven to be one of the main methods for producing new energy sources, fuel cell technology still has some problems that hinder fuel cell commercialization. Recently, new ideas on titanium dioxide are introduced as potential solution in several applications in fuel cell technology. Thus, this article presents an overview on the applications of titanium dioxide and highlights the unique properties and benefits of titanium dioxide in fuel cell technology.

  2. Microbial fuel cells

    SciTech Connect

    Nealson, Kenneth H; Pirbazari, Massoud; Hsu, Lewis

    2013-04-09

    A microbial fuel cell includes an anode compartment with an anode and an anode biocatalyst and a cathode compartment with a cathode and a cathode biocatalyst, with a membrane positioned between the anode compartment and the cathode compartment, and an electrical pathway between the anode and the cathode. The anode biocatalyst is capable of catalyzing oxidation of an organic substance, and the cathode biocatalyst is capable of catalyzing reduction of an inorganic substance. The reduced organic substance can form a precipitate, thereby removing the inorganic substance from solution. In some cases, the anode biocatalyst is capable of catalyzing oxidation of an inorganic substance, and the cathode biocatalyst is capable of catalyzing reduction of an organic or inorganic substance.

  3. Economics of Direct Hydrogen Polymer Electrolyte Membrane Fuel Cell Systems

    SciTech Connect

    Mahadevan, Kathyayani

    2011-10-04

    Battelle's Economic Analysis of PEM Fuel Cell Systems project was initiated in 2003 to evaluate the technology and markets that are near-term and potentially could support the transition to fuel cells in automotive markets. The objective of Battelle?s project was to assist the DOE in developing fuel cell systems for pre-automotive applications by analyzing the technical, economic, and market drivers of direct hydrogen PEM fuel cell adoption. The project was executed over a 6-year period (2003 to 2010) and a variety of analyses were completed in that period. The analyses presented in the final report include: Commercialization scenarios for stationary generation through 2015 (2004); Stakeholder feedback on technology status and performance status of fuel cell systems (2004); Development of manufacturing costs of stationary PEM fuel cell systems for backup power markets (2004); Identification of near-term and mid-term markets for PEM fuel cells (2006); Development of the value proposition and market opportunity of PEM fuel cells in near-term markets by assessing the lifecycle cost of PEM fuel cells as compared to conventional alternatives used in the marketplace and modeling market penetration (2006); Development of the value proposition of PEM fuel cells in government markets (2007); Development of the value proposition and opportunity for large fuel cell system application at data centers and wastewater treatment plants (2008); Update of the manufacturing costs of PEM fuel cells for backup power applications (2009).

  4. Heated transportable fuel cell cartridges

    DOEpatents

    Lance, Joseph R.; Spurrier, Francis R.

    1985-01-01

    A fuel cell stack protective system is made where a plurality of fuel cells, each containing liquid electrolyte subject to crystallization, is enclosed by a containing vessel, and where at least one electric heater is placed in the containing vessel and is capable of preventing electrolyte crystallization.

  5. Fuel cells: Hydrogen induced insulation

    NASA Astrophysics Data System (ADS)

    Zhou, Wei; Shao, Zongping

    2016-06-01

    Coupling high ionic and low electronic conductivity in the electrolyte of low-temperature solid-oxide fuel cells remains a challenge. Now, the electronic conductivity of a perovskite electrolyte, which has high proton conductivity, is shown to be heavily suppressed when exposed to hydrogen, leading to high fuel cell performance.

  6. Energy 101: Fuel Cell Technology

    ScienceCinema

    None

    2016-07-12

    Learn how fuel cell technology generates clean electricity from hydrogen to power our buildings and transportation-while emitting nothing but water. This video illustrates the fundamentals of fuel cell technology and its potential to supply our homes, offices, industries, and vehicles with sustainable, reliable energy.

  7. Bronx Zoo Fuel Cell Project

    SciTech Connect

    Hoang Pham

    2007-09-30

    A 200 kW Fuel Cell has been installed in the Lion House, Bronx Zoo, NY. The Fuel Cell is a 200 kW phosphoric acid type manufactured by United Technologies Corporation (UTC) and will provide thermal energy at 725,000 Btu/hr.

  8. Zirconia fuel cells and electrolyzers

    SciTech Connect

    Isaacs, H.S.

    1980-01-01

    A review of the historical development, operation, and problems of solid oxide electrolyte fuel cells and electrolyzers is given. The thermodynamic principles of operation are reviewed, and the overvoltage losses during operation of fuel cells and steam electrolyzers are discussed including physical factors and electrochemical factors. (WHK)

  9. Bonded polyimide fuel cell package

    DOEpatents

    Morse, Jeffrey D.; Jankowski, Alan; Graff, Robert T.; Bettencourt, Kerry

    2010-06-08

    Described herein are processes for fabricating microfluidic fuel cell systems with embedded components in which micron-scale features are formed by bonding layers of DuPont Kapton.TM. polyimide laminate. A microfluidic fuel cell system fabricated using this process is also described.

  10. Energy 101: Fuel Cell Technology

    SciTech Connect

    2014-03-11

    Learn how fuel cell technology generates clean electricity from hydrogen to power our buildings and transportation-while emitting nothing but water. This video illustrates the fundamentals of fuel cell technology and its potential to supply our homes, offices, industries, and vehicles with sustainable, reliable energy.

  11. In-situ diagnostic tools for hydrogen transfer leak characterization in PEM fuel cell stacks part II: Operational applications

    NASA Astrophysics Data System (ADS)

    Niroumand, Amir M.; Homayouni, Hooman; DeVaal, Jake; Golnaraghi, Farid; Kjeang, Erik

    2016-08-01

    This paper describes a diagnostic tool for in-situ characterization of the rate and distribution of hydrogen transfer leaks in Polymer Electrolyte Membrane (PEM) fuel cell stacks. The method is based on reducing the air flow rate from a high to low value at a fixed current, while maintaining an anode overpressure. At high air flow rates, the reduction in air flow results in lower oxygen concentration in the cathode and therefore reduction in cell voltages. Once the air flow rate in each cell reaches a low value at which the cell oxygen-starves, the voltage of the corresponding cell drops to zero. However, oxygen starvation results from two processes: 1) the electrochemical oxygen reduction reaction which produces current; and 2) the chemical reaction between oxygen and the crossed over hydrogen. In this work, a diagnostic technique has been developed that accounts for the effect of the electrochemical reaction on cell voltage to identify the hydrogen leak rate and number of leaky cells in a fuel cell stack. This technique is suitable for leak characterization during fuel cell operation, as it only requires stack air flow and voltage measurements, which are readily available in an operational fuel cell system.

  12. Fuel cells. Citations from the NTIS data base

    NASA Astrophysics Data System (ADS)

    Cavagnaro, D. M.

    1980-07-01

    Fuel cell applications, components, fabrication, design, catalysts, and chemistry are covered. The bibliography includes different types of fuel cells, such as hydrogen oxygen cells, hydrocarbon air cells, and biochemical cells. This updated bibliography contains 139 citations, 97 of which are new entries to the previous edition.

  13. Fuel cell system with interconnect

    DOEpatents

    Goettler, Richard; Liu, Zhien

    2015-03-10

    The present invention includes a fuel cell system having a plurality of adjacent electrochemical cells formed of an anode layer, a cathode layer spaced apart from the anode layer, and an electrolyte layer disposed between the anode layer and the cathode layer. The fuel cell system also includes at least one interconnect, the interconnect being structured to conduct free electrons between adjacent electrochemical cells. Each interconnect includes a primary conductor embedded within the electrolyte layer and structured to conduct the free electrons.

  14. Fuel cell system with interconnect

    DOEpatents

    Goettler, Richard; Liu, Zhien

    2015-08-11

    The present invention includes a fuel cell system having a plurality of adjacent electrochemical cells formed of an anode layer, a cathode layer spaced apart from the anode layer, and an electrolyte layer disposed between the anode layer and the cathode layer. The fuel cell system also includes at least one interconnect, the interconnect being structured to conduct free electrons between adjacent electrochemical cells. Each interconnect includes a primary conductor embedded within the electrolyte layer and structured to conduct the free electrons.

  15. Fuel cell system with interconnect

    DOEpatents

    Liu, Zhien; Goettler, Richard

    2015-09-29

    The present invention includes a fuel cell system having a plurality of adjacent electrochemical cells formed of an anode layer, a cathode layer spaced apart from the anode layer, and an electrolyte layer disposed between the anode layer and the cathode layer. The fuel cell system also includes at least one interconnect, the interconnect being structured to conduct free electrons between adjacent electrochemical cells. Each interconnect includes a primary conductor embedded within the electrolyte layer and structured to conduct the free electrons.

  16. Assessment of the Current Level of Automation in the Manufacture of Fuel Cell Systems for Combined Heat and Power Applications

    SciTech Connect

    Ulsh, M.; Wheeler, D.; Protopappas, P.

    2011-08-01

    The U.S. Department of Energy (DOE) is interested in supporting manufacturing research and development (R&D) for fuel cell systems in the 10-1,000 kilowatt (kW) power range relevant to stationary and distributed combined heat and power applications, with the intent to reduce manufacturing costs and increase production throughput. To assist in future decision-making, DOE requested that the National Renewable Energy Laboratory (NREL) provide a baseline understanding of the current levels of adoption of automation in manufacturing processes and flow, as well as of continuous processes. NREL identified and visited or interviewed key manufacturers, universities, and laboratories relevant to the study using a standard questionnaire. The questionnaire covered the current level of vertical integration, the importance of quality control developments for automation, the current level of automation and source of automation design, critical balance of plant issues, potential for continuous cell manufacturing, key manufacturing steps or processes that would benefit from DOE support for manufacturing R&D, the potential for cell or stack design changes to support automation, and the relationship between production volume and decisions on automation.

  17. Development and performance analysis of a metallic micro-direct methanol fuel cell for high-performance applications

    NASA Astrophysics Data System (ADS)

    Zhang, Bo; Zhang, Yufeng; He, Hong; Li, Jianmin; Yuan, Zhenyu; Na, Chaoran; Liu, Xiaowei

    As a promising candidate for conventional micro-power sources, the micro-direct methanol fuel cell (μDMFC) is currently attracting increased attention due to its various advantages and prospective suitability for portable applications. This paper reports the design, fabrication and analysis of a high-performance μDMFC with two metal current collectors. Employing micro-stamping technology, the current collectors are fabricated on 300-μm-thick stainless steel plates. The flow fields for both cathode and anode are uniform in shape and size. Two sheets of stainless steel mesh are added between the membrane electrode assembly (MEA) and current collectors in order to improve cell performance. To avoid electrochemical corrosion, titanium nitride (TiN) layers with thickness of 500 nm are deposited onto the surface of current collectors and stainless steel mesh. The performance of this metallic μDMFC is thoroughly studied by both simulation and experimental methods. The results show that all the parameters investigated, including current collector material, stainless steel mesh, anode feeding mode, methanol concentration, anode flow rate, and operating temperature have significant effects on cell performance. Moreover, the results show that under optimal operating conditions, the metallic μDMFC exhibits promising performance, yielding a maximum power density of 65.66 mW cm -2 at 40 °C and 115.0 mW cm -2 at 80 °C.

  18. Climate Change Fuel Cell Program

    SciTech Connect

    Alice M. Gitchell

    2006-09-15

    A 200 kW, natural gas fired fuel cell was installed at the Richard Stockton College of New Jersey. The purpose of this project was to demonstrate the financial and operational suitability of retrofit fuel cell technology at a medium sized college. Target audience was design professionals and the wider community, with emphasis on use in higher education. ''Waste'' heat from the fuel cell was utilized to supplement boiler operations and provide domestic hot water. Instrumentation was installed in order to measure the effectiveness of heat utilization. It was determined that 26% of the available heat was captured during the first year of operation. The economics of the fuel cell is highly dependent on the prices of electricity and natural gas. Considering only fuel consumed and energy produced (adjusted for boiler efficiency), the fuel cell saved $54,000 in its first year of operation. However, taking into account the price of maintenance and the cost of financing over the short five-year life span, the fuel cell operated at a loss, despite generous subsidies. As an educational tool and market stimulus, the fuel cell attracted considerable attention, both from design professionals and the general public.

  19. Novel method for screening microbes for application in microbial fuel cell.

    PubMed

    Szöllősi, Attila; Rezessy-Szabó, Judit M; Hoschke, Ágoston; Nguyen, Quang D

    2015-03-01

    The ability to produce and to transport exo-electrons by microbes either to external acceptors or to electrodes are reported in our study. All investigated microorganisms (exception of Lactobacillus plantarum) exhibited strong iron-reducing capabilities in the absence of mediator meaning production and secretion of exo-electrons to the growth medium. L.plantarum, Saccharomyces cerevisiae and Escherichia coli need an electron shuttle molecule to reduce Fe(3+) ion. Significant correlation was observed between growth and iron-reducing capacity, as well as between initial cell counts and iron-reducing capacity. Changes of bio-current generated in MFC and iron-reduction were experimentally monitored, and a mathematical model was established by regression analysis. Based on these results, a novel and rapid screening method was developed for the selection of microorganisms for potential application in MFC. The method is based on the measurement of absorbance of bacterial and yeast cultures at 460 nm, providing a robust and high sample throughput approach.

  20. INVESTIGATION OF NOVEL ALLOY TiC-Ni-Ni3Al FOR SOLID OXIDE FUEL CELL INTERCONNECT APPLICATIONS

    SciTech Connect

    Rasit Koc; Geoffrey Swift; Hua Xie

    2005-01-25

    Solid oxide fuel cell interconnect materials must meet stringent requirements. Such interconnects must operate at temperatures approaching 800 C while resisting oxidation and reduction, which can occur from the anode and cathode materials and the operating environment. They also must retain their electrical conductivity under these conditions and possess compatible coefficients of thermal expansion as the anode and cathode. Results are presented in this report for fuel cell interconnect candidate materials currently under investigation based upon nano-size titanium carbide (TiC) powders. The TiC is liquid phase sintered with either nickel (Ni) or nickel-aluminide (Ni{sub 3}Al) in varying concentrations. The oxidation resistance of the submicron grain TiC-metal materials is presented as a function weight change versus time at 700 C and 800 C for varying content of metal/intermetallic in the system. Electrical conductivity at 800 C as a function of time is also presented for TiC-Ni to demonstrate the vitality of these materials for interconnect applications. TGA studies showed that the weight gain was 0.8 mg/cm{sup 2} for TiC(30)-Ni(30wt.%) after 100 hours in wet air at 800 C and the weight gain was calculated to be 0.5205 mg/cm{sup 2} for TiC(30)- Ni(10 wt.%) after 100 hours at 700 C and 100 hours at 800 C. At room temperature the electrical conductivity was measured to be 2444 1/[ohm.cm] for TiC-Ni compositions. The electrical conductivities at 800 C in air was recorded to be 19 1/[ohm.cm] after 125 hours. Two identical samples were supplied to PNNL (Dr. Jeff Stevenson) for ASR testing during the pre-decision period and currently they are being tested there. Fabrication, oxidation resistance and electrical conductivity studies indicate that TiC-Ni-Ni{sub 3}Al ternary appears to be a very important system for the development of interconnect composition for solid oxide fuel cells.

  1. MOLTEN CARBONATE FUEL CELL PRODUCT DESIGN IMPROVEMENT

    SciTech Connect

    H. C. Maru; M. Farooque

    2003-12-19

    The ongoing program is designed to advance the carbonate fuel cell technology from full-size proof-of-concept field test to the commercial design. DOE has been funding Direct FuelCell{reg_sign} (DFC{reg_sign}) development at FuelCell Energy, Inc. (FCE) for stationary power plant applications. The program efforts are focused on technology and system optimization for cost reduction leading to commercial design development and prototype system field trials. FCE, Danbury, CT, is a world-recognized leader for the development and commercialization of high efficiency fuel cells that can generate clean electricity at power stations or in distributed locations near the customer, including hospitals, schools, universities, hotels and other commercial and industrial applications. FuelCell Energy has designed three different fuel cell power plant models (DFC300, DFC1500 and DFC3000). FCE's power plants are based on its patented Direct FuelCell technology, where the fuel is directly fed to fuel cell and hydrogen is generated internally. These power plants offer significant advantages compared to existing power generation technologies--higher fuel efficiency, significantly lower emissions, quieter operation, flexible siting and permitting requirements, scalability and potentially lower operating costs. Also, the exhaust heat by-product can be used for cogeneration applications such as high-pressure steam, district heating, and air conditioning. Several FCE sub-megawatt power plants are currently operating in Europe, Japan and the US. Because hydrogen is generated directly within the fuel cell module from readily available fuels such as natural gas and waste water treatment gas, DFC power plants are ready today and do not require the creation of a hydrogen infrastructure. Product improvement progress made during the reporting period in the areas of technology, manufacturing processes, cost reduction and balance of plant equipment designs is discussed in this report. FCE's DFC

  2. Advances in direct oxidation methanol fuel cells

    NASA Technical Reports Server (NTRS)

    Surampudi, S.; Narayanan, S. R.; Vamos, E.; Frank, H.; Halpert, G.; Laconti, Anthony B.; Kosek, J.; Prakash, G. K. Surya; Olah, G. A.

    1993-01-01

    Fuel cells that can operate directly on fuels such as methanol are attractive for low to medium power applications in view of their low weight and volume relative to other power sources. A liquid feed direct methanol fuel cell has been developed based on a proton exchange membrane electrolyte and Pt/Ru and Pt catalyzed fuel and air/O2 electrodes, respectively. The cell has been shown to deliver significant power outputs at temperatures of 60 to 90 C. The cell voltage is near 0.5 V at 300 mA/cm(exp 2) current density and an operating temperature of 90 C. A deterrent to performance appears to be methanol crossover through the membrane to the oxygen electrode. Further improvements in performance appear possible by minimizing the methanol crossover rate.

  3. The Russian/American Fuel Cell Consortium

    SciTech Connect

    Sylwester, A.; Baker, R.; Krumpelt, M.

    1996-12-31

    The United States and Russia discovered a mutual interest in fuel cell development during a series of workshops designed to teach entrepreneurial skills to Russian nuclear weapon scientists and engineers to aid them in converting their skill to peaceful applications. The proposal for a Russian/American Fuel Cell Consortium was initiated at the third workshop held in Livermore, CA, in May 1994. Representatives from U.S. fuel cell industries, U.S. research institutes, Russian institutes and ministries, and U.S. national laboratories attended, including those from GAZPROM, the Russian natural gas company. GASPROM needs to provide power for telemetry, cathodic corrosion protection of gas lines, and gas line pumping power in remote areas, and estimates that it needs approximately seventy thousand 1.5 to 15 KW plants to do so. Since the workshop, several direct working relationships have developed between the Russian Nuclear Weapon Institutes and the U.S. fuel cell industry.

  4. Catalytic autothermal reforming of hydrocarbon fuels for fuel cells.

    SciTech Connect

    Krumpelt, M.; Krause, T.; Kopasz, J.; Carter, D.; Ahmed, S.

    2002-01-11

    Fuel cell development has seen remarkable progress in the past decade because of an increasing need to improve energy efficiency as well as to address concerns about the environmental consequences of using fossil fuel for producing electricity and for propulsion of vehicles [1]. The lack of an infrastructure for producing and distributing H{sub 2} has led to a research effort to develop on-board fuel processing technology for reforming hydrocarbon fuels to generate H{sub 2} [2]. The primary focus is on reforming gasoline, because a production and distribution infrastructure for gasoline already exists to supply internal combustion engines [3]. Existing reforming technology for the production of H{sub 2} from hydrocarbon feedstocks used in large-scale manufacturing processes, such as ammonia synthesis, is cost prohibitive when scaled down to the size of the fuel processor required for transportation applications (50-80 kWe) nor is it designed to meet the varying power demands and frequent shutoffs and restarts that will be experienced during normal drive cycles. To meet the performance targets required of a fuel processor for transportation applications will require new reforming reactor technology developed to meet the volume, weight, cost, and operational characteristics for transportation applications and the development of new reforming catalysts that exhibit a higher activity and better thermal and mechanical stability than reforming catalysts currently used in the production of H{sub 2} for large-scale manufacturing processes.

  5. Fuel cell systems program plan, Fiscal year 1993

    SciTech Connect

    Not Available

    1993-07-01

    DOE Office of Fossil Energy (OoFE) is participating with private sector in developing molten carbon fuel cell (MCFC) and advanced concepts including solid oxide fuel cell for application in utility/commercial/industrial sectors. Phosphoric acid fuel cell (PAFC) development was sponsored by OoFE and is now being commercialized. In 1993 DOD is undertaking use and demonstration of PAFC and other fuel cells. DOE Office of Conservation and Renewable Energy is sponsoring fuel cell development for propulsion. The Conservation program is focused on polymer electrolyte or proton exchange membrane fuel cells, although they also are implementing a demonstration program for PAFC buses. DOE fuel cell research, development and demonstration efforts are also supported by private sector funding. This Plan describes the fuel cell activities of the Office of Fossil Energy.

  6. Solid Oxide Fuel Cell Development for Auxiliary Power in Heavy Duty Vehicle Applications

    SciTech Connect

    Daniel T. Hennessy

    2010-06-15

    Changing economic and environmental needs of the trucking industry is driving the use of auxiliary power unit (APU) technology for over the road haul trucks. The trucking industry in the United States remains the key to the economy of the nation and one of the major changes affecting the trucking industry is the reduction of engine idling. Delphi Automotive Systems, LLC (Delphi) teamed with heavy-duty truck Original Equipment Manufacturers (OEMs) PACCAR Incorporated (PACCAR), and Volvo Trucks North America (VTNA) to define system level requirements and develop an SOFC based APU. The project defines system level requirements, and subsequently designs and implements an optimized system architecture using an SOFC APU to demonstrate and validate that the APU will meet system level goals. The primary focus is on APUs in the range of 3-5 kW for truck idling reduction. Fuels utilized were derived from low-sulfur diesel fuel. Key areas of study and development included sulfur remediation with reformer operation; stack sensitivity testing; testing of catalyst carbon plugging and combustion start plugging; system pre-combustion; and overall system and electrical integration. This development, once fully implemented and commercialized, has the potential to significantly reduce the fuel idling Class 7/8 trucks consume. In addition, the significant amounts of NOx, CO2 and PM that are produced under these engine idling conditions will be virtually eliminated, inclusive of the noise pollution. The environmental impact will be significant with the added benefit of fuel savings and payback for the vehicle operators / owners.

  7. Opportunities for portable Ballard Fuel Cells

    SciTech Connect

    Voss, H.H.; Huff, J.R.

    1996-12-31

    With the increasing proliferation and sophistication of portable electronic devices in both commercial and military markets, the need has arisen for small, lightweight power supplies that can provide increased operating life over those presently available. A solution to this power problem is the development of portable Ballard Fuel Cell power systems that operate with a hydrogen fuel source and air. Ballard has developed PEM fuel cell stacks and power systems in the 25 to 100 watt range for both of these markets. For military use, Ballard has teamed with Ball Corporation and Hydrogen Consultants, Inc. and has provided the Ballard Fuel Cell stack for an ambient PEM fuel cell power system for the DoD. The system provides power from idle to I 00 watts and has the capability of delivering overloads of 125 watts for short periods of time. The system is designed to operate over a wide range of temperature, relative humidity and altitude. Hydrogen is supplied as a compressed gas, metal hydride or chemical hydride packaged in a unit that is mated to the power/control unit. The hydrogen sources provide 1.5, 5 and 15 kWh of operation, respectively. The design of the fuel cell power system enables the unit to operate at 12 volts or 24 volts depending upon the equipment being used. For commercial applications, as with the military, fuel cell power sources in the 25 to 500 watt range will be competing with advanced batteries. Ambient PEM fuel cell designs and demonstrators are being developed at 25 watts and other low power levels. Goals are minimum stack volume and weight and greatly enhanced operating life with reasonable system weight and volume. This paper will discuss ambient PEM fuel cell designs and performance and operating parameters for a number of power levels in the multiwatt range.

  8. Fuel cell with internal flow control

    SciTech Connect

    Haltiner, Jr., Karl J.; Venkiteswaran, Arun

    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.

  9. Corrosion resistant PEM fuel cell

    DOEpatents

    Li, Y.; Meng, W.J.; Swathirajan, S.; Harris, S.J.; Doll, G.L.

    1997-04-29

    The present invention contemplates a PEM fuel cell having electrical contact elements (including bipolar plates/septums) comprising a titanium nitride coated light weight metal (e.g., Al or Ti) core, having a passivating, protective metal layer intermediate the core and the titanium nitride. The protective layer forms a barrier to further oxidation/corrosion when exposed to the fuel cell`s operating environment. Stainless steels rich in Cr, Ni, and Mo are particularly effective protective interlayers. 6 figs.

  10. Carbonate fuel cells: Milliwatts to megawatts

    NASA Astrophysics Data System (ADS)

    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

  11. Climate Change Fuel Cell Program

    SciTech Connect

    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.

  12. Investigation of iron-chromium-niobium-titanium ferritic stainless steel for solid oxide fuel cell interconnect applications

    NASA Astrophysics Data System (ADS)

    Yang, Zhenguo; Xia, Guan-Guang; Wang, Chong-Min; Nie, Zimin; Templeton, Joshua; Stevenson, Jeffry W.; Singh, Prabhakar

    As part of an effort to develop cost-effective ferritic stainless steel-based interconnects for solid oxide fuel cell (SOFC) stacks, both bare AISI441 and AISI441 coated with (Mn,Co) 3O 4 protection layers were studied in terms of its metallurgical characteristics, oxidation behavior, and electrical performance. The addition of minor alloying elements, in particular Nb, led to formation of Laves phases both inside grains and along grain boundaries. In particular, the Laves phase which precipitated out along grain boundaries during exposure at intermediate SOFC operating temperatures was found to be rich in both Nb and Si. The capture of Si in the Laves phase minimized the Si activity in the alloy matrix and prevented formation of an insulating silica layer at the scale/metal interface, resulting in a reduction in area-specific electrical resistance (ASR). However, the relatively high oxidation rate of the steel, which leads to increasing ASR over time, and the need to prevent volatilization of chromium from the steel necessitates the application of a conductive protection layer on the steel. In particular, the application of a Mn 1.5Co 1.5O 4 spinel protection layer substantially improved the electrical performance of the 441 by reducing the oxidation rate.

  13. Power generation using spinel manganese-cobalt oxide as a cathode catalyst for microbial fuel cell applications.

    PubMed

    Mahmoud, Mohamed; Gad-Allah, Tarek A; El-Khatib, K M; El-Gohary, Fatma

    2011-11-01

    This study focused on the use of spinel manganese-cobalt (Mn-Co) oxide, prepared by a solid state reaction, as a cathode catalyst to replace platinum in microbial fuel cells (MFCs) applications. Spinel Mn-Co oxides, with an Mn/Co atomic ratios of 0.5, 1, and 2, were prepared and examined in an air cathode MFCs which was fed with a molasses-laden synthetic wastewater and operated in batch mode. Among the three Mn-Co oxide cathodes and after 300 h of operation, the Mn-Co oxide catalyst with Mn/Co atomic ratio of 2 (MnCo-2) exhibited the highest power generation 113 mW/m2 at cell potential of 279 mV, which were lower than those for the Pt catalyst (148 mW/m2 and 325 mV, respectively). This study indicated that using spinel Mn-Co oxide to replace platinum as a cathodic catalyst enhances power generation, increases contaminant removal, and substantially reduces the cost of MFCs.

  14. Analytical applications of microbial fuel cells. Part II: Toxicity, microbial activity and quantification, single analyte detection and other uses.

    PubMed

    Abrevaya, Ximena C; Sacco, Natalia J; Bonetto, Maria C; Hilding-Ohlsson, Astrid; Cortón, Eduardo

    2015-01-15

    Microbial fuel cells were rediscovered twenty years ago and now are a very active research area. The reasons behind this new activity are the relatively recent discovery of electrogenic or electroactive bacteria and the vision of two important practical applications, as wastewater treatment coupled with clean energy production and power supply systems for isolated low-power sensor devices. Although some analytical applications of MFCs were proposed earlier (as biochemical oxygen demand sensing) only lately a myriad of new uses of this technology are being presented by research groups around the world, which combine both biological-microbiological and electroanalytical expertises. This is the second part of a review of MFC applications in the area of analytical sciences. In Part I a general introduction to biological-based analytical methods including bioassays, biosensors, MFCs design, operating principles, as well as, perhaps the main and earlier presented application, the use as a BOD sensor was reviewed. In Part II, other proposed uses are presented and discussed. As other microbially based analytical systems, MFCs are satisfactory systems to measure and integrate complex parameters that are difficult or impossible to measure otherwise, such as water toxicity (where the toxic effect to aquatic organisms needed to be integrated). We explore here the methods proposed to measure toxicity, microbial metabolism, and, being of special interest to space exploration, life sensors. Also, some methods with higher specificity, proposed to detect a single analyte, are presented. Different possibilities to increase selectivity and sensitivity, by using molecular biology or other modern techniques are also discussed here.

  15. Fuel Cell Research

    SciTech Connect

    Weber, Peter M.

    2014-03-30

    Executive Summary In conjunction with the Brown Energy Initiative, research Projects selected for the fuel cell research grant were selected on the following criteria: They should be fundamental research that has the potential to significantly impact the nation’s energy infrastructure. They should be scientifically exciting and sound. They should synthesize new materials, lead to greater insights, explore new phenomena, or design new devices or processes that are of relevance to solving the energy problems. They involve top-caliper senior scientists with a record of accomplishment, or junior faculty with outstanding promise of achievement. They should promise to yield at least preliminary results within the given funding period, which would warrant further research development. They should fit into the overall mission of the Brown Energy Initiative, and the investigators should contribute as partners to an intellectually stimulating environment focused on energy science. Based on these criteria, fourteen faculty across three disciplines (Chemistry, Physics and Engineering) and the Charles Stark Draper Laboratory were selected to participate in this effort.1 In total, there were 30 people supported, at some level, on these projects. This report highlights the findings and research outcomes of the participating researchers.

  16. SAVANNAH RIVER NATIONAL LABORATORYREGENERATIVE FUEL CELL PROJECT

    SciTech Connect

    Motyka, T

    2008-11-11

    A team comprised of governmental, academic and industrial partners led by the Savannah River National Laboratory developed and demonstrated a regenerative fuel cell system for backup power applications. Recent market assessments have identified emergency response and telecommunication applications as promising near-term markets for fuel cell backup power systems. The Regenerative Fuel Cell System (RFC) consisted of a 2 kg-per-day electrolyzer, metal-hydride based hydrogen storage units and a 5 kW fuel cell. Coupling these components together created a system that can produce and store its own energy from the power grid much like a rechargeable battery. A series of test were conducted to evaluate the performance of the RFC system under both steady-state and transit conditions that might be encountered in typical backup power applications. In almost all cases the RFC functioned effectively. Test results from the demonstration project will be used to support recommendations for future fuel cell and hydrogen component and system designs and support potential commercialization activities. In addition to the work presented in this report, further testing of the RFC system at the Center for Hydrogen Research in Aiken County, SC is planned including evaluating the system as a renewable system coupled with a 20kW-peak solar photovoltaic array.

  17. European opportunities for fuel cell commercialisation

    NASA Astrophysics Data System (ADS)

    Gibbs, C. E.; Steel, M. C. F.

    1992-01-01

    developing European sub-systems, others have chosen to develop their own novel cell technology. This paper will survey the extent of the fuel cell activities in Europe and emphasise the particular markets which fuel cell manufacturers are targeting. Demand for fuel cells in defence and military applications will be the first sector to be commercially viable — European companies such as Siemens, Elenco and VSEL are already marketing AFC or PEM systems for naval and aerospace applications. The small-scale CHP sector is also a likely early market for fuel cell plant. Co-generation fuel cells are of great interest to gas companies like ENAGAS and British Gas looking to promote sales of gas by installing on-site gas-fired generators on their customers' premises. The market for utility scale fuel cell plants is expected to develop later in the decade. The largest demonstration planned for Europe is the 1 MW PAFC for Milan, due to come onstream in 1992. MBB GmbH is considering developing MW-scale MCFC plants with the US company ERC — a 2 MW demonstration is planned for the end of 1993. The potential market for utility fuel cells is large — installation rates could reach 500-1000 MW/year by the turn of the century. Fuel cells will probably not achieve significant use in transport applications in Europe until after the turn of the century unless very stringent emissions legislation for vehicles is introduced. The likely early markets for fuel cells in the transport sector seem to be for delivery and fleet vehicles. Examples of European projects in this area include the Amsterdam city bus project which will use Elenco's AFC technology and Siemens' fork lift truck which will incorporate a PEM fuel cell. Fuel cells also link conveniently with renewable energy systems — coupled with an electrolyser a fuel cell can store solar, wind or wave power. The electrolysis proces is used to generate hydrogen from water at times of surplus energy while the fuel cell consumes hydrogen fuel

  18. Water reactive hydrogen fuel cell power system

    SciTech Connect

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

    2014-11-25

    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 the fuel cartridge to generate hydrogen for the fuel cell which then produces power for the user.

  19. Water reactive hydrogen fuel cell power system

    SciTech Connect

    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.

  20. Diesel fueled ship propulsion fuel cell demonstration project

    SciTech Connect

    Kumm, W.H.

    1996-12-31

    The paper describes the work underway to adapt a former US Navy diesel electric drive ship as a 2.4 Megawatt fuel cell powered, US Coast Guard operated, demonstrator. The Project will design the new configuration, and then remove the four 600 kW diesel electric generators and auxiliaries. It will design, build and install fourteen or more nominal 180 kW diesel fueled molten carbonate internal reforming direct fuel cells (DFCs). The USCG cutter VINDICATOR has been chosen. The adaptation will be carried out at the USCG shipyard at Curtis Bay, MD. A multi-agency (state and federal) cooperative project is now underway. The USCG prime contractor, AEL, is performing the work under a Phase III Small Business Innovation Research (SBIR) award. This follows their successful completion of Phases I and II under contract to the US Naval Sea Systems (NAVSEA) from 1989 through 1993 which successfully demonstrated the feasibility of diesel fueled DFCs. The demonstrated marine propulsion of a USCG cutter will lead to commercial, naval ship and submarine applications as well as on-land applications such as diesel fueled locomotives.