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Note: This page contains sample records for the topic "oxide fuel fabrication" from the National Library of EnergyBeta (NLEBeta).
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1

Fuel Fabrication Facility  

National Nuclear Security Administration (NNSA)

Construction of the Mixed Oxide Fuel Fabrication Facility Construction of the Mixed Oxide Fuel Fabrication Facility November 2005 May 2007 June 2008 May 2012...

2

Fabrication of solid oxide fuel cell by electrochemical vapor deposition  

DOE Patents (OSTI)

In a high temperature solid oxide fuel cell (SOFC), the deposition of an impervious high density thin layer of electrically conductive interconnector material, such as magnesium doped lanthanum chromite, and of an electrolyte material, such as yttria stabilized zirconia, onto a porous support/air electrode substrate surface is carried out at high temperatures (approximately 1100.degree.-1300.degree. C.) by a process of electrochemical vapor deposition. In this process, the mixed chlorides of the specific metals involved react in the gaseous state with water vapor resulting in the deposit of an impervious thin oxide layer on the support tube/air electrode substrate of between 20-50 microns in thickness. An internal heater, such as a heat pipe, is placed within the support tube/air electrode substrate and induces a uniform temperature profile therein so as to afford precise and uniform oxide deposition kinetics in an arrangement which is particularly adapted for large scale, commercial fabrication of SOFCs.

Brian, Riley (Willimantic, CT); Szreders, Bernard E. (Oakdale, CT)

1989-01-01T23:59:59.000Z

3

Fabrication of solid oxide fuel cell by electrochemical vapor deposition  

DOE Patents (OSTI)

In a high temperature solid oxide fuel cell (SOFC), the deposition of an impervious high density thin layer of electrically conductive interconnector material, such as magnesium doped lanthanum chromite, and of an electrolyte material, such as yttria stabilized zirconia, onto a porous support/air electrode substrate surface is carried out at high temperatures (/approximately/1100/degree/ /minus/ 1300/degree/C) by a process of electrochemical vapor deposition. In this process, the mixed chlorides of the specific metals involved react in the gaseous state with water vapor resulting in the deposit of an impervious thin oxide layer on the support tube/air electrode substrate of between 20--50 microns in thickness. An internal heater, such as a heat pipe, is placed within the support tube/air electrode substrate and induces a uniform temperature profile therein so as to afford precise and uniform oxide deposition kinetics in an arrangement which is particularly adapted for large scale, commercial fabrication of SOFCs.

Riley, B.; Szreders, B.E.

1988-04-26T23:59:59.000Z

4

Development of metallic substrate supported planar solid oxide fuel cells fabricated by atmospheric plasma spraying  

Science Journals Connector (OSTI)

A planar solid oxide fuel cell (SOFC) consisting of a cell supported with a porous metallic substrate and a metallic separator has been developed. In the fabrication of the cell, anodes and electrolytes were form...

Shunji Takenoiri; Naruaki Kadokawa; Kazuo Koseki

2000-09-01T23:59:59.000Z

5

Method of fabricating a monolithic solid oxide fuel cell  

DOE Patents (OSTI)

In a two-step densifying process of making a monolithic solid oxide fuel cell, a limited number of anode-electrolyte-cathode cells separated by an interconnect layer are formed and partially densified. Subsequently, the partially densified cells are stacked and further densified to form a monolithic array.

Minh, Nguyen Q. (Fountain Valley, CA); Horne, Craig R. (Redondo Beach, CA)

1994-01-01T23:59:59.000Z

6

The Use of Staff Augmentation Subcontracts at the National Nuclear Security Administration's Mixed Oxide Fuel Fabrication Facility, IG-0887  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

The Use of Staff Augmentation The Use of Staff Augmentation Subcontracts at National Nuclear Security Administration's Mixed Oxide Fuel Fabrication Facility DOE/IG-0887 May 2013 U.S. Department of Energy Office of Inspector General Office of Audits and Inspections Department of Energy Washington, DC 20585 May 15, 2013 MEMORANDUM FOR THE SECRETARY FROM: Gregory H. Friedman Inspector General SUBJECT: INFORMATION: Audit Report on "The Use of Staff Augmentation Subcontracts at the National Nuclear Security Administration's Mixed Oxide Fuel Fabrication Facility" BACKGROUND Shaw AREVA MOX Services, LLC (MOX Services) is responsible for the design and construction of the National Nuclear Security Administration's (NNSA) nearly $5 billion Mixed

7

Evaluation of existing United States` facilities for use as a mixed-oxide (MOX) fuel fabrication facility for plutonium disposition  

SciTech Connect

A number of existing US facilities were evaluated for use as a mixed-oxide fuel fabrication facility for plutonium disposition. These facilities include the Fuels Material Examination Facility (FMEF) at Hanford, the Washington Power Supply Unit 1 (WNP-1) facility at Hanford, the Barnwell Nuclear Fuel Plant (BNFP) at Barnwell, SC, the Fuel Processing Facility (FPF) at Idaho National Engineering Laboratory (INEL), the Device Assembly Facility (DAF) at the Nevada Test Site (NTS), and the P-reactor at the Savannah River Site (SRS). The study consisted of evaluating each facility in terms of available process space, available building support systems (i.e., HVAC, security systems, existing process equipment, etc.), available regional infrastructure (i.e., emergency response teams, protective force teams, available transportation routes, etc.), and ability to integrate the MOX fabrication process into the facility in an operationally-sound manner that requires a minimum amount of structural modifications.

Beard, C.A.; Buksa, J.J.; Chidester, K.; Eaton, S.L.; Motley, F.E.; Siebe, D.A.

1995-12-31T23:59:59.000Z

8

Method of fabricating a monolithic core for a solid oxide fuel cell  

DOE Patents (OSTI)

A method is disclosed for forming a core for use in a solid oxide fuel cell that electrochemically combines fuel and oxidant for generating galvanic output. The core has an array of electrolyte and interconnect walls that are substantially devoid of any composite inert materials for support consisting instead only of the active anode, cathode, electrolyte and interconnect materials. Each electrolyte wall consists of cathode and anode materials sandwiching electrolyte material therebetween, and each interconnect wall consists of the cathode and anode materials sandwiching interconnect material therebetween. The electrolyte and interconnect walls define a plurality of substantially parallel core passageways alternately having respectively the inside faces thereof with only the anode material or with only the cathode material exposed. In the wall structure, the electrolyte and interconnect materials are only 0.002-0.01 cm thick; and the cathode and anode materials are only 0.002-0.05 cm thick. The method consists of building up the electrolyte and interconnect walls by depositing each material on individually and endwise of the wall itself, where each material deposit is sequentially applied for one cycle; and where the depositing cycle is repeated many times until the material buildup is sufficient to formulate the core. The core is heat cured to become dimensionally and structurally stable.

Zwick, Stanley A. (Woodridge, IL); Ackerman, John P. (Downers Grove, IL)

1985-01-01T23:59:59.000Z

9

Fabrication and characterization of anode-supported single chamber solid oxide fuel cell based on La0.6Sr0.4Co0.2Fe0.8O3--  

E-Print Network (OSTI)

Fabrication and characterization of anode-supported single chamber solid oxide fuel cell based-supported solid oxide fuel cells consisting of nickel-gadolinium doped ceria (NiO-CGO, 60:40 wt%) anode-CGO cathode 1. Introduction Single-chamber solid oxide fuel cells (SC-SOFCs) have received many attentions

Paris-Sud XI, Université de

10

Modeling of Solid Oxide Fuel Cell functionally graded electrodes and a feasibility study of fabrication techniques for functionally graded electrodes.  

E-Print Network (OSTI)

??Currently, Solid Oxide Fuel Cell (SOFC) electrodes have not been explored for optimization of graded electrodes and nonlinear functional grading. In this work, a complete… (more)

Flesner, Reuben

2009-01-01T23:59:59.000Z

11

Solid Oxide Fuel Cells  

Science Journals Connector (OSTI)

A Solid Oxide Fuel Cell (SOFC) is typically composed of two porous electrodes, interposed between an electrolyte made of a particular solid oxide ceramic material. The system originates from the work of Nernst...

Nigel M. Sammes; Roberto Bove; Jakub Pusz

2006-01-01T23:59:59.000Z

12

LANL disassembles "pits," makes mixed-oxide fuel  

NLE Websites -- All DOE Office Websites (Extended Search)

at the MOX facility in South Carolina, the plutonium oxide from LANL will be blended with depleted uranium, fabricated into MOX fuel, and irradiated in domestic nuclear...

13

Fabrication and electrical properties of La8.33Sb(SiO4)6O2 thick films for solid oxide fuel cells  

Science Journals Connector (OSTI)

In this study Sb-substituted La8.33Sb(SiO4)6O2 apatite thick films were fabricated by using a screen printing method and the structural and electrical properties of these materials with variation in sintering temperature for solid oxide fuel cells were investigated. With increased sintering temperatures the second phase La2SiO5 phase decreased and the specimens sintered at over 1350?°C showed typical X-ray diffraction patterns of apatite polycrystalline structure. The grain size increased and porosity decreased with increasing sintering temperatures. The thickness of all films was approximately 25–30??m. La8.33Sb(SiO4)6O2 thick films sintered at 1350?°C showed good conductivity and activation energy characteristics at 9.87?×?10?5 S cm?1and 1.24?eV respectively.

Dae-Young Kim; Sung-Gap Lee

2013-01-01T23:59:59.000Z

14

Method of electrode fabrication for solid oxide electrochemical cells  

DOE Patents (OSTI)

A process for fabricating cermet electrodes for solid oxide electrochemical cells by sintering is disclosed. First, a porous metal electrode is fabricated on a solid oxide cell, such as a fuel cell by, for example, sintering, and is then infiltrated with a high volume fraction stabilized zirconia suspension. A second sintering step is used to sinter the infiltrated zirconia to a high density in order to more securely attach the electrode to the solid oxide electrolyte of the cell. High performance fuel electrodes can be obtained with this process. Further electrode performance enhancement may be achieved if stabilized zirconia doped with cerium oxide, chromium oxide, titanium oxide, and/or praseodymium oxide for electronic conduction is used.

Jensen, Russell R. (Murrysville, PA)

1990-01-01T23:59:59.000Z

15

Method of electrode fabrication for solid oxide electrochemical cells  

DOE Patents (OSTI)

A process for fabricating cermet electrodes for solid oxide electrochemical cells by sintering is disclosed. First, a porous metal electrode is fabricated on a solid oxide cell, such as a fuel cell by, for example, sintering, and is then infiltrated with a high volume fraction stabilized zirconia suspension. A second sintering step is used to sinter the infiltrated zirconia to a high density in order to more securely attach the electrode to the solid oxide electrolyte of the cell. High performance fuel electrodes can be obtained with this process. Further electrode performance enhancement may be achieved if stabilized zirconia doped with cerium oxide, chromium oxide, titanium oxide, and/or praseodymium oxide for electronic conduction is used. 5 figs.

Jensen, R.R.

1990-11-20T23:59:59.000Z

16

Nanotube Fabrication byNanotube Fabrication by Anodic Aluminum Oxide,Anodic Aluminum Oxide,  

E-Print Network (OSTI)

Nanotube Fabrication byNanotube Fabrication by Anodic Aluminum Oxide,Anodic Aluminum Oxide, Self-regulating phenomena in materials science: Self-assembly of nanopores during anodic oxidation of aluminum (AAO) Self combined anodic aluminum oxide (AAO) nanostructures with atomic layer deposition (ALD) to fabricate

Rubloff, Gary W.

17

Fabrication and Characterization of Fully Ceramic Microencapsulated Fuels  

SciTech Connect

The current generation of fully ceramic microencapsulated fuels, consisting of Tristructural Isotropic fuel particles embedded in a silicon carbide matrix, is fabricated by hot pressing. Matrix powder feedstock is comprised of alumina - yttria additives thoroughly mixed with silicon carbide nanopowder using polyethyleneimine as a dispersing agent. Fuel compacts are fabricated by hot pressing the powder - fuel particle mixture at a temperature of 1800-1900 C using compaction pressures of 10-20 MPa. Detailed microstructural characterization of the final fuel compacts shows that oxide additives are limited in extent and are distributed uniformly at silicon carbide grain boundaries, at triple joints between silicon carbide grains, and at the fuel particle-matrix interface.

Terrani, Kurt A [ORNL; Kiggans, Jim [ORNL; Katoh, Yutai [ORNL; Shimoda, Kazuya [Kyoto University, Japan; Montgomery, Fred C [ORNL; Armstrong, Beth L [ORNL; Parish, Chad M [ORNL; Hinoki, Tatsuya [Kyoto University, Japan; Hunn, John D [ORNL; Snead, Lance Lewis [ORNL

2012-01-01T23:59:59.000Z

18

Fuel injector Holes (Fabrication of Micro-Orifices for Fuel Injectors...  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

injector Holes (Fabrication of Micro-Orifices for Fuel Injectors) Fuel injector Holes (Fabrication of Micro-Orifices for Fuel Injectors) 2009 DOE Hydrogen Program and Vehicle...

19

Solid oxide fuel cell generator  

DOE Patents (OSTI)

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.

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

1993-11-02T23:59:59.000Z

20

Enhanced Thermal Conductivity Oxide Fuels  

SciTech Connect

the purpose of this project was to investigate the feasibility of increasing the thermal conductivity of oxide fuels by adding small fractions of a high conductivity solid phase.

Alvin Solomon; Shripad Revankar; J. Kevin McCoy

2006-01-17T23:59:59.000Z

Note: This page contains sample records for the topic "oxide fuel fabrication" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


21

Nanostructured Solid Oxide Fuel Cell Electrodes  

E-Print Network (OSTI)

post-Doping of Solid Oxide Fuel Cell Cathodes,? P.h.D.and V. I. Birss, in Solid Oxide Fuel Cells (SOFC IX), S. C.Nanostructured Solid Oxide Fuel Cell Electrodes By Tal Zvi

Sholklapper, Tal Zvi

2007-01-01T23:59:59.000Z

22

Fuel Fabrication Capability Research and Development Plan  

SciTech Connect

The purpose of this document is to provide a comprehensive review of the mission of the Fuel Fabrication Capability (FFC) within the Global Threat Reduction Initiative Convert Program, along with research and development (R&D) needs that have been identified as necessary to ensuring mission success. The design and fabrication of successful nuclear fuels must be closely linked endeavors. Therefore, the overriding motivation behind the FFC R&D program described in this plan is to foster closer integration between fuel design and fabrication to reduce programmatic risk. These motivating factors are all interrelated, and progress addressing one will aid understanding of the others. The FFC R&D needs fall into two principal categories, 1) baseline process optimization, to refine the existing fabrication technologies, and 2) manufacturing process alternatives, to evaluate new fabrication technologies that could provide improvements in quality, repeatability, material utilization, or cost. The FFC R&D Plan examines efforts currently under way in regard to coupon, foil, plate, and fuel element manufacturing, and provides recommendations for a number of R&D topics that are of high priority but not currently funded (i.e., knowledge gaps). The plan ties all FFC R&D efforts into a unified vision that supports the overall Convert Program schedule in general, and the fabrication schedule leading up to the MP-1 and FSP-1 irradiation experiments specifically. The fabrication technology decision gates and down-selection logic and schedules are tied to the schedule for fabricating the MP-1 fuel plates, which will provide the necessary data to make a final fuel fabrication process down-selection. Because of the short turnaround between MP-1 and the follow-on FSP-1 and MP-2 experiments, the suite of specimen types that will be available for MP-1 will be the same as those available for FSP-1 and MP-2. Therefore, the only opportunity to explore parameter space and alternative processing is between now and 2016 when the candidate processes are down-selected in preparation for the MP-1, FSP-1, and MP-2 plate manufacturing campaigns. A number of key risks identified by the FFC are discussed in this plan, with recommended mitigating actions for those activities within FFC, and identification of risks that are impacted by activities in other areas of the Convert Program. The R&D Plan does not include discussion of FFC initiatives related to production-scale manufacturing of fuel (e.g., establishment of the Pilot Line Production Facility), rather, the goal of this plan is to document the R&D activities needed ultimately to enable high-quality and cost-effective production of the fuel by the commercial fuel fabricator. The intent is for this R&D Plan to be a living document that will be reviewed and updated on a regular basis (e.g., annually) to ensure that FFC R&D activities remain properly aligned to the needs of the Convert Program. This version of the R&D Plan represents the first annual review and revision.

Senor, David J.; Burkes, Douglas

2014-04-17T23:59:59.000Z

23

Fabrication of Cerium Oxide and Uranium Oxide Microspheres for Space Nuclear Power Applications  

SciTech Connect

Cerium oxide and uranium oxide microspheres are being produced via an internal gelation sol-gel method to investigate alternative fabrication routes for space nuclear fuels. Depleted uranium and non-radioactive cerium are being utilized as surrogates for plutonium-238 (Pu-238) used in radioisotope thermoelectric generators and for enriched uranium required by nuclear thermal rockets. While current methods used to produce Pu-238 fuels at Los Alamos National Laboratory (LANL) involve the generation of fine powders that pose a respiratory hazard and have a propensity to contaminate glove boxes, the sol-gel route allows for the generation of oxide microsphere fuels through an aqueous route. The sol-gel method does not generate fine powders and may require fewer processing steps than the LANL method with less operator handling. High-quality cerium dioxide microspheres have been fabricated in the desired size range and equipment is being prepared to establish a uranium dioxide microsphere production capability.

Jeffrey A. Katalenich; Michael R. Hartman; Robert C. O'Brien

2013-02-01T23:59:59.000Z

24

Update on US High Density Fuel Fabrication Development  

SciTech Connect

Second generation uranium molybdenum fuel has shown excellent in-reactor irradiation performance. This metallic fuel type is capable of being fabricated at much higher loadings than any presently used research reactor fuel. Due to the broad range of fuel types this alloy system encompasses—fuel powder to monolithic foil and binary fuel systems to multiple element additions—significant amounts of research and development have been conducted on the fabrication of these fuels. This paper presents an update of the US RERTR effort to develop fabrication techniques and the fabrication methods used for the RERTR-9A miniplate test.

C.R. Clark; G.A. Moore; J.F. Jue; B.H. Park; N.P. Hallinan; D.M. Wachs; D.E. Burkes

2007-03-01T23:59:59.000Z

25

Solid oxide fuel cell generator  

DOE Patents (OSTI)

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.

Draper, Robert (Churchill Boro, PA); George, Raymond A. (Pittsburgh, PA); Shockling, Larry A. (Plum Borough, PA)

1993-01-01T23:59:59.000Z

26

EA-0534: Radioisotope Heat Source Fuel Processing and Fabrication, Los  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

4: Radioisotope Heat Source Fuel Processing and Fabrication, 4: Radioisotope Heat Source Fuel Processing and Fabrication, Los Alamos, New Mexico EA-0534: Radioisotope Heat Source Fuel Processing and Fabrication, Los Alamos, New Mexico SUMMARY This EA evaluates the environmental impacts of a proposal to operate existing Pu-238 processing facilities at Savannah River Site, and fabricate a limited quantity of Pu-238 fueled heat sources at an existing facility at U.S. Department of Energy's Los Alamos National Laboratory. PUBLIC COMMENT OPPORTUNITIES None available at this time. DOCUMENTS AVAILABLE FOR DOWNLOAD July 19, 1991 EA-0534: Finding of No Significant Impact Radioisotope Heat Source Fuel Processing and Fabrication July 19, 1991 EA-0534: Final Environmental Assessment Radioisotope Heat Source Fuel Processing and Fabrication

27

Development of Solid Oxide Fuel Cells Utilizing Alternative Fuels.  

E-Print Network (OSTI)

??This dissertation is a summary of four solid oxide fuel cell (SOFC) research projects which addressed a number of SOFC technologies to use alternative fuels… (more)

Labarbera, Mark

2012-01-01T23:59:59.000Z

28

FUEL CELLS – SOLID OXIDE FUEL CELLS | Systems  

Science Journals Connector (OSTI)

In this article, some basic arrangements of solid oxide fuel cell (SOFC) systems are described, starting with atmospheric systems using a catalytic burner or a thermal burner and anode gas recycling. For illustrating the potential electrical efficiency of SOFC systems, their combination with a gas turbine and also with a steam turbine (ST) are described. To be able to evaluate the potential of the different systems, first the essential efficiencies relevant to fuel cell systems are defined and then the basics of calculating energy balance are illustrated. Equations are given to describe, for example, the effect of fuel recycling on system fuel utilization and of internal reforming on the necessary air flow for cooling the stack. It is obvious that electrical efficiency depends strongly on cell voltage and fuel utilization. In the case of cells that operate with a high fuel utilization at cell voltages of 800 mV, a net electrical efficiency above 55% can be achieved. The combination in a pressurized system with a gas turbine enables efficiencies of up to 70% and combining this system with an additional ST allows efficiencies of up to 75%. However, an investigation into the size of these \\{STs\\} shows that such combined systems make sense only above a gas input of 10 MW.

L. Blum; E. Riensche

2009-01-01T23:59:59.000Z

29

SOLID OXIDE PLANAR AND TUBULAR SOLID OXIDE FUEL  

E-Print Network (OSTI)

SOLID OXIDE PLANAR AND TUBULAR SOLID OXIDE FUEL CELLS Dynamic Simulation Approach Modular Approach · Parallel planes: PSOFC · Other: combustor, reformer Solid Oxide Fuel Cell Electrochemistry Cell Reactions · Slow pressure transients #12;Fuel Cell Assumptions · H2 electrochemically oxidized only · CO consumed

Mease, Kenneth D.

30

Mathematical modeling of solid oxide fuel cells using hydrocarbon fuels  

E-Print Network (OSTI)

Solid oxide fuel cells (SOFCs) are high efficiency conversion devices that use hydrogen or light hydrocarbon (HC) fuels in stationary applications to produce quiet and clean power. While successful, HC-fueled SOFCs face ...

Lee, Won Yong, Ph. D. Massachusetts Institute of Technology

2012-01-01T23:59:59.000Z

31

Heating subsurface formations by oxidizing fuel on a fuel carrier  

DOE Patents (OSTI)

A method of heating a portion of a subsurface formation includes drawing fuel on a fuel carrier through an opening formed in the formation. Oxidant is supplied to the fuel at one or more locations in the opening. The fuel is combusted with the oxidant to provide heat to the formation.

Costello, Michael; Vinegar, Harold J.

2012-10-02T23:59:59.000Z

32

MONOLITHIC FUEL FABRICATION PROCESS DEVELOPMENT AT THE IDAHO NATIONAL LABORATORY  

SciTech Connect

Within the Reduced Enrichment for Research and Test Reactors (RERTR) program directed by the US Department of Energy (DOE), UMo fuel-foils are being developed in an effort to realize high density monolithic fuel plates for use in high-flux research and test reactors. Namely, targeted are reactors that are not amenable to Low Enriched Uranium (LEU) fuel conversion via utilization of high density dispersion-based fuels, i.e. 8-9 gU/cc. LEU conversion of reactors having a need for >8-9 gU/cc fuel density will only be possible by way of monolithic fuel forms. The UMo fuel foils under development afford fuel meat density of ~16 gU/cc and thus have the potential to facilitate LEU conversions without any significant reactor-performance penalty. Two primary challenges have been established with respect to UMo monolithic fuel development; namely, fuel element fabrication and in-reactor fuel element performance. Both issues are being addressed concurrently at the Idaho National Laboratory. An overview is provided of the ongoing monolithic UMo fuel development effort at the Idaho National Laboratory (INL); including development of complex/graded fuel foils. Fabrication processes to be discussed include: UMo alloying and casting, foil fabrication via hot rolling, fuel-clad interlayer application via co-rolling and thermal spray processes, clad bonding via Hot Isostatic Pressing (HIP) and Friction Bonding (FB), and fuel plate finishing.

Glenn A. Moore; Francine J. Rice; Nicolas E. Woolstenhulme; W. David SwanK; DeLon C. Haggard; Jan-Fong Jue; Blair H. Park; Steven E. Steffler; N. Pat Hallinan; Michael D. Chapple; Douglas E. Burkes

2008-10-01T23:59:59.000Z

33

Advanced Safeguards Approaches for New TRU Fuel Fabrication Facilities  

SciTech Connect

This second report in a series of three reviews possible safeguards approaches for the new transuranic (TRU) fuel fabrication processes to be deployed at AFCF – specifically, the ceramic TRU (MOX) fuel fabrication line and the metallic (pyroprocessing) line. The most common TRU fuel has been fuel composed of mixed plutonium and uranium dioxide, referred to as “MOX”. However, under the Advanced Fuel Cycle projects custom-made fuels with higher contents of neptunium, americium, and curium may also be produced to evaluate if these “minor actinides” can be effectively burned and transmuted through irradiation in the ABR. A third and final report in this series will evaluate and review the advanced safeguards approach options for the ABR. In reviewing and developing the advanced safeguards approach for the new TRU fuel fabrication processes envisioned for AFCF, the existing international (IAEA) safeguards approach at the Plutonium Fuel Production Facility (PFPF) and the conceptual approach planned for the new J-MOX facility in Japan have been considered as a starting point of reference. The pyro-metallurgical reprocessing and fuel fabrication process at EBR-II near Idaho Falls also provided insight for safeguarding the additional metallic pyroprocessing fuel fabrication line planned for AFCF.

Durst, Philip C.; Ehinger, Michael H.; Boyer, Brian; Therios, Ike; Bean, Robert; Dougan, A.; Tolk, K.

2007-12-15T23:59:59.000Z

34

Impact of the Fuel Molecular Structure on the Oxidation Process...  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

Oxidation Process of Real Diesel fuels According to Storage Conditions and Biodiesel Content Impact of the Fuel Molecular Structure on the Oxidation Process of Real Diesel fuels...

35

Comments on Americium Volatilization during Fuel Fabrication for Fast Reactors  

SciTech Connect

The physical processes relevant to the fabrication of metallic and ceramic nuclear fuels are analyzed, with attention to recycling of fuels containing U, Pu, and minor volatile actinides for the use in fast reactors. This analysis is relevant to the development of a process model that can be used for the numerical simulation and prediction of the spatial distribution of composition in the fuel, an important factor in fuel performance.

Sabau, Adrian S [ORNL; Ohriner, Evan Keith [ORNL

2008-01-01T23:59:59.000Z

36

MONOLITHIC FUEL FABRICATION PROCESS DEVELOPMENT AT THE IDAHO NATIONAL LABORATORY_  

SciTech Connect

Full-size/prototypic U10Mo monolithic fuel-foils and aluminum clad fuel plates are being developed at the Idaho National Laboratory’s (INL) Materials and Fuels Complex (MFC). These efforts are focused on realizing Low Enriched Uranium (LEU) high density monolithic fuel plates for use in High Performance Research and Test Reactors. The U10Mo fuel foils under development afford a fuel meat density of ~16 gU/cc and thus have the potential to facilitate LEU conversions without any significant reactor-performance penalty. An overview is provided of the ongoing monolithic UMo fuel development effort, including application of a zirconium barrier layer on fuel foils, fabrication scale-up efforts, and development of complex/graded fuel foils. Fuel plate clad bonding processes to be discussed include: Hot Isostatic Pressing (HIP) and Friction Bonding (FB).

G. A. Moore; F. J. Rice; N. E. Woolstenhulme; J-F. Jue; B. H. Park; S. E. Steffler; N. P. Hallinan; M. D. Chapple; M. C. Marshall; B. L. Mackowiak; C. R. Clark; B. H. Rabin

2009-11-01T23:59:59.000Z

37

Intermediate Temperature Solid Oxide Fuel Cell Development  

SciTech Connect

Solid oxide fuel cells (SOFCs) are high efficiency energy conversion devices. Present materials set, using yttria stabilized zirconia (YSZ) electrolyte, limit the cell operating temperatures to 800 C or higher. It has become increasingly evident however that lowering the operating temperature would provide a more expeditious route to commercialization. The advantages of intermediate temperature (600 to 800 C) operation are related to both economic and materials issues. Lower operating temperature allows the use of low cost materials for the balance of plant and limits degradation arising from materials interactions. When the SOFC operating temperature is in the range of 600 to 700 C, it is also possible to partially reform hydrocarbon fuels within the stack providing additional system cost savings by reducing the air preheat heat-exchanger and blower size. The promise of Sr and Mg doped lanthanum gallate (LSGM) electrolyte materials, based on their high ionic conductivity and oxygen transference number at the intermediate temperature is well recognized. The focus of the present project was two-fold: (a) Identify a cell fabrication technique to achieve the benefits of lanthanum gallate material, and (b) Investigate alternative cathode materials that demonstrate low cathode polarization losses at the intermediate temperature. A porous matrix supported, thin film cell configuration was fabricated. The electrode material precursor was infiltrated into the porous matrix and the counter electrode was screen printed. Both anode and cathode infiltration produced high performance cells. Comparison of the two approaches showed that an infiltrated cathode cells may have advantages in high fuel utilization operations. Two new cathode materials were evaluated. Northwestern University investigated LSGM-ceria composite cathode while Caltech evaluated Ba-Sr-Co-Fe (BSCF) based pervoskite cathode. Both cathode materials showed lower polarization losses at temperatures as low as 600 C than conventional manganite or cobaltite cathodes.

S. Elangovan; Scott Barnett; Sossina Haile

2008-06-30T23:59:59.000Z

38

Breakout Group 5: Solid Oxide Fuel Cells  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Oxide Fuel Cells PARTICIPANTS Name Organization Robert Ploessl Corning, Inc. Tim Armstrong Oak Ridge National Laboratory Barbara Heydorn SRI International Suresh Baskaran...

39

NETL: Solid Oxide Fuel Cells Publications  

NLE Websites -- All DOE Office Websites (Extended Search)

Solid Oxide Fuel Cells Publications Operating Principles AEC Development Atmospheric Pressure Systems Pressurized Systems Program Plan Project Portfolio Project Information Systems...

40

Coated U(Mo) Fuel: As-Fabricated Microstructures  

SciTech Connect

As part of the development of low-enriched uranium fuels, fuel plates have recently been tested in the BR-2 reactor as part of the SELENIUM experiment. These fuel plates contained fuel particles with either Si or ZrN thin film coating (up to 1 µm thickness) around the U-7Mo fuel particles. In order to best understand irradiation performance, it is important to determine the starting microstructure that can be observed in as-fabricated fuel plates. To this end, detailed microstructural characterization was performed on ZrN and Si-coated U-7Mo powder in samples taken from AA6061-clad fuel plates fabricated at 500°C. Of interest was the condition of the thin film coatings after fabrication at a relatively high temperature. Both scanning electron microscopy and transmission electron microscopy were employed. The ZrN thin film coating was observed to consist of columns comprised of very fine ZrN grains. Relatively large amounts of porosity could be found in some areas of the thin film, along with an enrichment of oxygen around each of the the ZrN columns. In the case of the pure Si thin film coating sample, a (U,Mo,Al,Si) interaction layer was observed around the U-7Mo particles. Apparently, the Si reacted with the U-7Mo and Al matrix during fuel plate fabrication at 500°C to form this layer. The microstructure of the formed layer is very similar to those that form in U-7Mo versus Al-Si alloy diffusion couples annealed at higher temperatures and as-fabricated U-7Mo dispersion fuel plates with Al-Si alloy matrix fabricated at 500°C.

Emmanuel Perez; Dennis D. Keiser, Jr.; Ann Leenaers; Sven Van den Berghe; Tom Wiencek

2014-04-01T23:59:59.000Z

Note: This page contains sample records for the topic "oxide fuel fabrication" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


41

Solid Oxide Fuel Cells | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Solid Oxide Fuel Cells Solid Oxide Fuel Cells Solid Oxide Fuel Cells FE researchers at NETL have developed a unique test platform, called the multi-cell array (MCA), to rapidly test multiple fuel cells and determine how they degrade when contaminants exist in the fuel stream, such as might occur when using syngas from a coal gasifier. FE researchers at NETL have developed a unique test platform, called the multi-cell array (MCA), to rapidly test multiple fuel cells and determine how they degrade when contaminants exist in the fuel stream, such as might occur when using syngas from a coal gasifier. Fuel cells are an energy user's dream: an efficient, combustion-less, virtually pollution-free power source, capable of being sited in downtown urban areas or in remote regions that runs almost silently and has few

42

Characterization of candidate DOE sites for fabricating MOX fuel for lead assemblies  

SciTech Connect

The Office of Fissile Materials Disposition (MD) of the Department of Energy (DOE) is directing the program to disposition US surplus weapons-usable plutonium. For the reactor option for disposition of this surplus plutonium, MD is seeking to contract with a consortium, which would include a mixed-oxide (MOX) fuel fabricator and a commercial US reactor operator, to fabricate and burn MOX fuel in existing commercial nuclear reactors. This option would entail establishing a MOX fuel fabrication facility under the direction of the consortium on an existing DOE site. Because of the lead time required to establish a MOX fuel fabrication facility and the need to qualify the MOX fuel for use in a commercial reactor, MD is considering the early fabrication of lead assemblies (LAs) in existing DOE facilities under the technical direction of the consortium. The LA facility would be expected to produce a minimum of 1 metric ton heavy metal per year and must be operational by June 2003. DOE operations offices were asked to identify candidate sites and facilities to be evaluated for suitability to fabricate MOX fuel LAs. Savannah River Site, Argonne National Laboratory-West, Hanford, Lawrence Livermore National Laboratory, and Los Alamos National Laboratory were identified as final candidates to host the LA project. A Site Evaluation Team (SET) worked with each site to develop viable plans for the LA project. SET then characterized the suitability of each of the five plans for fabricating MOX LAs using 28 attributes and documented the characterization to aid DOE and the consortium in selecting the site for the LA project. SET concluded that each option has relative advantages and disadvantages in comparison with other options; however, each could meet the requirements of the LA project as outlined by MD and SET.

Holdaway, R.F.; Miller, J.W.; Sease, J.D.; Moses, R.J.; O`Connor, D.G. [Oak Ridge National Lab., TN (United States); Carrell, R.D. [Technical Resources International, Inc., Richland, WA (United States); Jaeger, C.D. [Sandia National Labs., Albuquerque, NM (United States); Thompson, M.L.; Strasser, A.A. [Delta-21 Resources, Inc., Oak Ridge, TN (United States)

1998-03-01T23:59:59.000Z

43

Solid oxide fuel cell with monolithic core  

DOE Patents (OSTI)

A solid oxide fuel cell in which fuel and oxidant gases undergo an electrochemical reaction to produce an electrical output includes a monolithic core comprised of a corrugated conductive sheet disposed between upper and lower generally flat sheets. The corrugated sheet includes a plurality of spaced, parallel, elongated slots which form a series of closed, linear, first upper and second lower gas flow channels with the upper and lower sheets within which a fuel gas and an oxidant gas respectively flow. Facing ends of the fuel cell are generally V-shaped and provide for fuel and oxidant gas inlet and outlet flow, respectively, and include inlet and outlet gas flow channels which are continuous with the aforementioned upper fuel gas and lower oxidant gas flow channels. The upper and lower flat sheets and the intermediate corrugated sheet are preferably comprised of ceramic materials and are securely coupled together such as by assembly in the green state and sintering together during firing at high temperatures. A potential difference across the fuel cell, or across a stacked array of similar fuel cells, is generated when an oxidant gas such as air and a fuel such as hydrogen gas is directed through the fuel cell at high temperatures, e.g., between 700 C and 1,100 C. 8 figs.

McPheeters, C.C.; Mrazek, F.C.

1988-08-02T23:59:59.000Z

44

Solid oxide fuel cell with monolithic core  

DOE Patents (OSTI)

A solid oxide fuel cell in which fuel and oxidant gases undergo an electrochemical reaction to produce an electrical output includes a monolithic core comprised of a corrugated conductive sheet disposed between upper and lower generally flat sheets. The corrugated sheet includes a plurality of spaced, parallel, elongated slots which form a series of closed, linear, first upper and second lower gas flow channels with the upper and lower sheets within which a fuel gas and an oxidant gas respectively flow. Facing ends of the fuel cell are generally V-shaped and provide for fuel and oxidant gas inlet and outlet flow, respectively, and include inlet and outlet gas flow channels which are continuous with the aforementioned upper fuel gas and lower oxidant gas flow channels. The upper and lower flat sheets and the intermediate corrugated sheet are preferably comprised of ceramic materials and are securely coupled together such as by assembly in the green state and sintering together during firing at high temperatures. A potential difference across the fuel cell, or across a stacked array of similar fuel cells, is generated when an oxidant gas such as air and a fuel such as hydrogen gas is directed through the fuel cell at high temperatures, e.g., between 700.degree. C. and 1100.degree. C.

McPheeters, Charles C. (Plainfield, IL); Mrazek, Franklin C. (Hickory Hills, IL)

1988-01-01T23:59:59.000Z

45

Low Temperature Constrained Sintering of Cerium Gadolinium Oxide Films for Solid Oxide Fuel Cell Applications  

E-Print Network (OSTI)

Temperature Solid Oxide Fuel Cells, In: S.C. Singhal and M.solidoxide.html, Tubular Solid Oxide Fuel Cell Technology,Oxide Films for Solid Oxide Fuel Cell Applications by Jason

Nicholas, Jason.D.

2007-01-01T23:59:59.000Z

46

Interactions of nickel/zirconia solid oxide fuel cell anodes...  

NLE Websites -- All DOE Office Websites (Extended Search)

Interactions of nickelzirconia solid oxide fuel cell anodes with coal gas containing arsenic. Interactions of nickelzirconia solid oxide fuel cell anodes with coal gas containing...

47

Low Cost Fabrication of Oxide Dispersion Strengthened Materials  

NLE Websites -- All DOE Office Websites (Extended Search)

Low Cost Fabrication of Oxide Dispersion Low Cost Fabrication of Oxide Dispersion Strengthened Materials Background To obtain significant increases in the efficiency of coal fired power plants, steam pressure and temperature must be increased beyond current technology to advanced ultra-supercritical (A-USC) conditions -temperatures and pressures up to 760 degrees Celsius (°C) and 35 megapascals (MPa). The upper bounds of operating pressure and temperature are limited by the properties of the current set

48

Interfacial material for solid oxide fuel cell  

DOE Patents (OSTI)

Solid oxide fuel cells having improved low-temperature operation are disclosed. In one embodiment, an interfacial layer of terbia-stabilized zirconia is located between the air electrode and electrolyte of the solid oxide fuel cell. The interfacial layer provides a barrier which controls interaction between the air electrode and electrolyte. The interfacial layer also reduces polarization loss through the reduction of the air electrode/electrolyte interfacial electrical resistance. In another embodiment, the solid oxide fuel cell comprises a scandia-stabilized zirconia electrolyte having high electrical conductivity. The scandia-stabilized zirconia electrolyte may be provided as a very thin layer in order to reduce resistance. The scandia-stabilized electrolyte is preferably used in combination with the terbia-stabilized interfacial layer. The solid oxide fuel cells are operable over wider temperature ranges and wider temperature gradients in comparison with conventional fuel cells.

Baozhen, Li (Essex Junction, VT); Ruka, Roswell J. (Pittsburgh, PA); Singhal, Subhash C. (Murrysville, PA)

1999-01-01T23:59:59.000Z

49

Metallic Materials in Solid Oxide Fuel Cells  

Science Journals Connector (OSTI)

Fe-Cr alloys with variations in chromium content and additions of different elements were studied for potential application in intermediate temperature Solid Oxide Fuel Cell (SOFC). Recently, a new type of FeC...

V. Shemet; J. Piron-Abellan; W.J. Quadakkers…

2005-01-01T23:59:59.000Z

50

Modeling of solid oxide fuel cells  

E-Print Network (OSTI)

A comprehensive membrane-electrode assembly (MEA) model of Solid Oxide Fuel Cell (SOFC)s is developed to investigate the effect of various design and operating conditions on the cell performance and to examine the underlying ...

Lee, Won Yong, S.M. Massachusetts Institute of Technology

2006-01-01T23:59:59.000Z

51

Interconnection of bundled solid oxide fuel cells  

DOE Patents (OSTI)

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

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

2014-01-14T23:59:59.000Z

52

Sintered electrode for solid oxide fuel cells  

DOE Patents (OSTI)

A solid oxide fuel cell fuel electrode is produced by a sintering process. An underlayer is applied to the electrolyte of a solid oxide fuel cell in the form of a slurry, which is then dried. An overlayer is applied to the underlayer and then dried. The dried underlayer and overlayer are then sintered to form a fuel electrode. Both the underlayer and the overlayer comprise a combination of electrode metal such as nickel, and stabilized zirconia such as yttria-stabilized zirconia, with the overlayer comprising a greater percentage of electrode metal. The use of more stabilized zirconia in the underlayer provides good adhesion to the electrolyte of the fuel cell, while the use of more electrode metal in the overlayer provides good electrical conductivity. The sintered fuel electrode is less expensive to produce compared with conventional electrodes made by electrochemical vapor deposition processes. The sintered electrodes exhibit favorable performance characteristics, including good porosity, adhesion, electrical conductivity and freedom from degradation.

Ruka, Roswell J. (Pittsburgh, PA); Warner, Kathryn A. (Bryan, TX)

1999-01-01T23:59:59.000Z

53

Breakout Group 5: Solid Oxide Fuel Cells | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Breakout Group 5: Solid Oxide Fuel Cells Breakout Group 5: Solid Oxide Fuel Cells Report from Breakout Group 5 of the Fuel Cell Pre-Solicitation Workshop, January 23-24, 2008...

54

FABRICATION OF URANIUM OXYCARBIDE KERNELS AND COMPACTS FOR HTR FUEL  

SciTech Connect

As part of the program to demonstrate tristructural isotropic (TRISO)-coated fuel for the Next Generation Nuclear Plant (NGNP), Advanced Gas Reactor (AGR) fuel is being irradiation tested in the Advanced Test Reactor (ATR) at Idaho National Laboratory (INL). This testing has led to improved kernel fabrication techniques, the formation of TRISO fuel particles, and upgrades to the overcoating, compaction, and heat treatment processes. Combined, these improvements provide a fuel manufacturing process that meets the stringent requirements associated with testing in the AGR experimentation program. Researchers at Idaho National Laboratory (INL) are working in conjunction with a team from Babcock and Wilcox (B&W) and Oak Ridge National Laboratory (ORNL) to (a) improve the quality of uranium oxycarbide (UCO) fuel kernels, (b) deposit TRISO layers to produce a fuel that meets or exceeds the standard developed by German researches in the 1980s, and (c) develop a process to overcoat TRISO particles with the same matrix material, but applies it with water using equipment previously and successfully employed in the pharmaceutical industry. A primary goal of this work is to simplify the process, making it more robust and repeatable while relying less on operator technique than prior overcoating efforts. A secondary goal is to improve first-pass yields to greater than 95% through the use of established technology and equipment. In the first test, called “AGR-1,” graphite compacts containing approximately 300,000 coated particles were irradiated from December 2006 to November 2009. The AGR-1 fuel was designed to closely replicate many of the properties of German TRISO-coated particles, thought to be important for good fuel performance. No release of gaseous fission product, indicative of particle coating failure, was detected in the nearly 3-year irradiation to a peak burn up of 19.6% at a time-average temperature of 1038–1121°C. Before fabricating AGR-2 fuel, each fabrication process was improved and changed. Changes to the kernel fabrication process included replacing the carbon black powder feed with a surface-modified carbon slurry and shortening the sintering schedule. AGR-2 TRISO particles were produced in a 6-inch diameter coater using a charge size about 21-times that of the 2-inch diameter coater used to coat AGR-1 particles. The compacting process was changed to increase matrix density and throughput by increasing the temperature and pressure of pressing and using a different type of press. AGR-2 fuel began irradiation in the ATR in late spring 2010.

Dr. Jeffrey A. Phillips; Eric L. Shaber; Scott G. Nagley

2012-10-01T23:59:59.000Z

55

Los Alamos National Laboratory summary plan to fabricate mixed oxide lead assemblies for the fissile material disposition program  

SciTech Connect

This report summarizes an approach for using existing Los Alamos National Laboratory (Laboratory) mixed oxide (MOX) fuel-fabrication and plutonium processing capabilities to expedite and assure progress in the MOX/Reactor Plutonium Disposition Program. Lead Assembly MOX fabrication is required to provide prototypic fuel for testing in support of fuel qualification and licensing requirements. It is also required to provide a bridge for the full utilization of the European fabrication experience. In part, this bridge helps establish, for the first time since the early 1980s, a US experience base for meeting the safety, licensing, safeguards, security, and materials control and accountability requirements of the Department of Energy and Nuclear Regulatory Commission. In addition, a link is needed between the current research and development program and the production of disposition mission fuel. This link would also help provide a knowledge base for US regulators. Early MOX fabrication and irradiation testing in commercial nuclear reactors would provide a positive demonstration to Russia (and to potential vendors, designers, fabricators, and utilities) that the US has serious intent to proceed with plutonium disposition. This report summarizes an approach to fabricating lead assembly MOX fuel using the existing MOX fuel-fabrication infrastructure at the Laboratory.

Buksa, J.J.; Eaton, S.L.; Trellue, H.R.; Chidester, K.; Bowidowicz, M.; Morley, R.A.; Barr, M.

1997-12-01T23:59:59.000Z

56

FUEL & TARGET FABRICATION Aiken County, South Carolina  

NLE Websites -- All DOE Office Websites (Extended Search)

& TARGET FABRICATION & TARGET FABRICATION Aiken County, South Carolina 300/M AREA 300/M AREA SAVANNAH RIVER SITE COLD WAR HISTORIC PROPERTY DOCUMENTATION ii ABSTRACT This documentation was prepared in accordance with a Memorandum of Agreement (MOA) signed by the Department of Energy-Savannah River (DOE-SR) and the South Carolina Historic Preservation Office (SHPO) dated February 27, 2003, as well as the Consolidated MOA of August 2004. The MOA stipulated that a thematic study and photographic documentation be produced that told the story of 300/M Area's genesis, its operational history, and its closure. New South Associates prepared the narrative and Westinghouse Savannah River Company (WSRC) completed the photographic documentation. M Area is the site of Savannah River Plant's fuel and target fabrication facilities operated from 1955

57

Fabrication of small-orifice fuel injectors for diesel engines.  

SciTech Connect

Diesel fuel injector nozzles with spray hole diameters of 50-75 {micro}m have been fabricated via electroless nickel plating of conventionally made nozzles. Thick layers of nickel are deposited onto the orifice interior surfaces, reducing the diameter from {approx}200 {micro}m to the target diameter. The nickel plate is hard, smooth, and adherent, and covers the orifice interior surfaces uniformly.

Woodford, J. B.; Fenske, G. R.

2005-04-08T23:59:59.000Z

58

A New Instrument For Characterizing Solid Oxide Fuel Cell Catalysts  

E-Print Network (OSTI)

RESEARCH HIGHLIGHTS A New Instrument For Characterizing Solid Oxide Fuel Cell Catalysts From fuels to renewable energy sources. Solid oxide fuel cells (SOFCs) have enormous potential in this area A New Instrument For Characterizing Solid Oxide Fuel Cell Catalysts Rob Usiskin In partnership

59

Effect of Coal Gas Contaminants on Solid Oxide Fuel Cell Operation...  

NLE Websites -- All DOE Office Websites (Extended Search)

Coal Gas Contaminants on Solid Oxide Fuel Cell Operation. Effect of Coal Gas Contaminants on Solid Oxide Fuel Cell Operation. Abstract: The operation of solid oxide fuel cells...

60

One dimensional modeling of planar solid oxide fuel cell.  

E-Print Network (OSTI)

??Using modeling and simulation, the present work offers parametric study for Planar Solid Oxide Fuel Cell (PSOFC) as a function of fuel gas composition. The… (more)

Ghosh, Ujjal

2005-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "oxide fuel fabrication" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


61

SULFUR-TOLERANT CATALYST FOR THE SOLID OXIDE FUEL CELL.  

E-Print Network (OSTI)

??JP-8 fuel is easily accessible, transportable, and has hydrogen content essential to solid oxide fuel cell (SOFC) operation. However, this syngas has sulfur content which… (more)

Bozeman, Joe Frank, III

2010-01-01T23:59:59.000Z

62

National Energy Technology Laboratory Publishes Solid Oxide Fuel Cell  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

National Energy Technology Laboratory Publishes Solid Oxide Fuel National Energy Technology Laboratory Publishes Solid Oxide Fuel Cell Studies National Energy Technology Laboratory Publishes Solid Oxide Fuel Cell Studies July 23, 2013 - 1:07pm Addthis National Energy Technology Laboratory Publishes Solid Oxide Fuel Cell Studies What does this project do? For more information on DOE's efforts to make solid oxide fuel cells an efficient and economically compelling option, please visit: The NETL Solid Oxide Fuel Cells Program Webpage Solid oxide fuel cells are among the cleanest, most efficient power-generating technologies now being developed. They provide excellent electrical efficiencies and are capable of operating on a wide variety of fuels, from coal and natural gas to landfill waste and hydrogen. And with continued advancements, solid oxide fuel cells can provide clean

63

Silicon Based Solid Oxide Fuel Cell Chip for Portable Consumer Electronics -- Final Technical Report  

SciTech Connect

LSI’s fuel cell uses efficient Solid Oxide Fuel Cell (“SOFC”) technology, is manufactured using Micro Electrical Mechanical System (“MEMS”) fabrication methods, and runs on high energy fuels, such as butane and ethanol. The company’s Fuel Cell on a Chip™ technology enables a form-factor battery replacement for portable electronic devices that has the potential to provide an order-of-magnitude run-time improvement over current batteries. Further, the technology is clean and environmentally-friendly. This Department of Energy funded project focused on accelerating the commercialization and market introduction of this technology through improvements in fuel cell chip power output, lifetime, and manufacturability.

Alan Ludwiszewski

2009-06-29T23:59:59.000Z

64

In situ reduction and oxidation of nickel from solid oxide fuel cells in a Titan ETEM  

E-Print Network (OSTI)

In situ reduction and oxidation of nickel from solid oxide fuel cells in a Titan ETEM A. Faes1. C. Singhal, K. Kendall, High Temperature Solid Oxide Fuel Cell - Fundamentals, Design, Denmark antonin.faes@epfl.ch Keywords: In situ ETEM, nickel oxide, reduction, RedOx, SOFC Solid Oxide Fuel

Dunin-Borkowski, Rafal E.

65

Tubular solid oxide fuel cell current collector  

DOE Patents (OSTI)

An internal current collector for use inside a tubular solid oxide fuel cell (TSOFC) electrode comprises a tubular coil spring disposed concentrically within a TSOFC electrode and in firm uniform tangential electrical contact with the electrode inner surface. The current collector maximizes the contact area between the current collector and the electrode. The current collector is made of a metal that is electrically conductive and able to survive under the operational conditions of the fuel cell, i.e., the cathode in air, and the anode in fuel such as hydrogen, CO, CO.sub.2, H.sub.2O or H.sub.2S.

Bischoff, Brian L. (Knoxville, TN); Sutton, Theodore G. (Kingston, TN); Armstrong, Timothy R. (Clinton, TN)

2010-07-20T23:59:59.000Z

66

Solid oxide fuel cell process and apparatus  

DOE Patents (OSTI)

Conveying gas containing sulfur through a sulfur tolerant planar solid oxide fuel cell (PSOFC) stack for sulfur scrubbing, followed by conveying the gas through a non-sulfur tolerant PSOFC stack. The sulfur tolerant PSOFC stack utilizes anode materials, such as LSV, that selectively convert H.sub.2S present in the fuel stream to other non-poisoning sulfur compounds. The remaining balance of gases remaining in the completely or near H.sub.2S-free exhaust fuel stream is then used as the fuel for the conventional PSOFC stack that is downstream of the sulfur-tolerant PSOFC. A broad range of fuels such as gasified coal, natural gas and reformed hydrocarbons are used to produce electricity.

Cooper, Matthew Ellis (Morgantown, WV); Bayless, David J. (Athens, OH); Trembly, Jason P. (Durham, NC)

2011-11-15T23:59:59.000Z

67

Robust control strategies for hybrid solid oxide fuel cell systems.  

E-Print Network (OSTI)

??Solid Oxide Fuel Cell (SOFC) systems are electrochemical energy conversion devices characterized by the use of solid oxide as the electrolyte. They operate at high… (more)

Mathew, Anju Ann

2010-01-01T23:59:59.000Z

68

Surplus weapons plutonium: Technologies for pit disassembly/conversion and MOX fuel fabrication  

SciTech Connect

This paper will provide a description of the technologies involved in the disposition of plutonium from surplus nuclear weapon components (pits), based on pit disassembly and conversion and on fabrication of mixed oxide (MOX) fuel for disposition through irradiation in nuclear reactors. The MOX/Reactor option is the baseline disposition plan for both the US and russian for plutonium from pits and other clean plutonium metal and oxide. In the US, impure plutonium in various forms will be converted to oxide and immobilized in glass or ceramic, surrounded by vitrified high level waste to provide a radiation barrier. A similar fate is expected for impure material in Russia as well. The immobilization technologies will not be discussed. Following technical descriptions, a discussion of options for monitoring the plutonium during these processes will be provided.

Toevs, J.W.

1997-12-31T23:59:59.000Z

69

Reversible Poisoning of the Nickel/Zirconia Solid Oxide Fuel...  

NLE Websites -- All DOE Office Websites (Extended Search)

Poisoning of the NickelZirconia Solid Oxide Fuel Cell Anodes by Hydrogen Chloride in Coal Gas. Reversible Poisoning of the NickelZirconia Solid Oxide Fuel Cell Anodes by Hydrogen...

70

Generator configuration for solid oxide fuel cells  

DOE Patents (OSTI)

Disclosed are improvements in a solid oxide fuel cell generator 1 having a multiplicity of electrically connected solid oxide fuel cells 2, where a fuel gas is passed over one side of said cells and an oxygen-containing gas is passed over the other side of said cells resulting in the generation of heat and electricity. The improvements comprise arranging the cells in the configuration of a circle, a spiral, or folded rows within a cylindrical generator, and modifying the flow rate, oxygen concentration, and/or temperature of the oxygen-containing gases that flow to those cells that are at the periphery of the generator relative to those cells that are at the center of the generator. In these ways, a more uniform temperature is obtained throughout the generator.

Reichner, Philip (Plum Boro, PA)

1989-01-01T23:59:59.000Z

71

Sintered electrode for solid oxide fuel cells  

DOE Patents (OSTI)

A solid oxide fuel cell fuel electrode is produced by a sintering process. An underlayer is applied to the electrolyte of a solid oxide fuel cell in the form of a slurry, which is then dried. An overlayer is applied to the underlayer and then dried. The dried underlayer and overlayer are then sintered to form a fuel electrode. Both the underlayer and the overlayer comprise a combination of electrode metal such as nickel, and stabilized zirconia such as yttria-stabilized zirconia, with the overlayer comprising a greater percentage of electrode metal. The use of more stabilized zirconia in the underlayer provides good adhesion to the electrolyte of the fuel cell, while the use of more electrode metal in the overlayer provides good electrical conductivity. The sintered fuel electrode is less expensive to produce compared with conventional electrodes made by electrochemical vapor deposition processes. The sintered electrodes exhibit favorable performance characteristics, including good porosity, adhesion, electrical conductivity and freedom from degradation. 4 figs.

Ruka, R.J.; Warner, K.A.

1999-06-01T23:59:59.000Z

72

Fuel cell collector plate and method of fabrication  

DOE Patents (OSTI)

An improved molding composition is provided for compression molding or injection molding a current collector plate for a polymer electrolyte membrane fuel cell. The molding composition is comprised of a polymer resin combined with a low surface area, highly-conductive carbon and/or graphite powder filler. The low viscosity of the thermoplastic resin combined with the reduced filler particle surface area provide a moldable composition which can be fabricated into a current collector plate having improved current collecting capacity vis-a-vis comparable fluoropolymer molding compositions.

Braun, James C. (Juno Beach, FL); Zabriskie, Jr., John E. (Port St. Lucie, FL); Neutzler, Jay K. (Palm Beach Gardens, FL); Fuchs, Michel (Boynton Beach, FL); Gustafson, Robert C. (Palm Beach Gardens, FL)

2001-01-01T23:59:59.000Z

73

In Situ Studies of Fuel Oxidation in Solid Oxide Fuel Cells  

Science Journals Connector (OSTI)

In Situ Studies of Fuel Oxidation in Solid Oxide Fuel Cells ... Re-optimization of the Raman signal shows two broad, strong features in the OCV spectrum indicating large amounts of disordered graphite as evidenced by a broad D band (at 1350 cm-1) accompanying the G band (at 1585 cm-1) (Figure 2, right panel). ... intensities from a nonresonant, bond polarizability model optimized for sp2 carbon are also in qual. ...

Michael B. Pomfret; Jeffrey C. Owrutsky; Robert A. Walker

2007-02-13T23:59:59.000Z

74

FUEL CELLS – SOLID OXIDE FUEL CELLS | Internal and External Reformation  

Science Journals Connector (OSTI)

Three basic concepts of solid oxide fuel cell (SOFC) systems operating on hydrocarbon fuels, with external, internal, and partial prereforming, respectively, are presented and discussed. Internal reforming of methane is advantageously used for additional cooling of the SOFC stack, thus increasing system efficiency. Basic thermodynamics, catalysis, and kinetics of the methane steam reforming process are presented. Examples of SOFC stacks operating on internal reforming of methane and simulated partial prereforming of mine gas and natural gas are discussed. The latter is used to illustrate the effect of internal methane reforming on heat management in SOFC stacks.

L.G.J. de Haart; R. Peters

2009-01-01T23:59:59.000Z

75

COMPUTATIONAL FLUID DYNAMICS MODELING OF SOLID OXIDE FUEL CELLS  

E-Print Network (OSTI)

COMPUTATIONAL FLUID DYNAMICS MODELING OF SOLID OXIDE FUEL CELLS Ugur Pasaogullari and Chao-dimensional model has been developed to simulate solid oxide fuel cells (SOFC). The model fully couples current density operation. INTRODUCTION Solid oxide fuel cells (SOFC) are among possible candidates

76

Mechanical Engineering Manufacturing Solid Oxide Fuel Cells for Improved Electro-  

E-Print Network (OSTI)

Uday Pal Mechanical Engineering Manufacturing Solid Oxide Fuel Cells for Improved Electro- chemical for the commercialization of solid oxide fuel cells (SOFCs) are its high manufacturing and material costs expressed in terms at 800oC with humidified hydrogen (3% H2O) as the fuel and air as the oxidant. The cells were also tested

Lin, Xi

77

Model-based Interpretation of the Performance and Degradation of Reformate Fueled Solid Oxide Fuel Cells.  

E-Print Network (OSTI)

??Solid oxide fuel cells offer great prospects for the sustainable, clean and safe conversion of various fuels into electrical energy. In this thesis, the performance-determining… (more)

Kromp, Alexander

2013-01-01T23:59:59.000Z

78

Biogas fuel reforming for solid oxide fuel cells  

Science Journals Connector (OSTI)

In this paper strategies for biogas reforming and their ensuing effects on solid oxide fuel cell(SOFC) performance are explored. Synthesized biogas (65% CH4?+?35% CO2) fuel streams are reformed over a rhodium catalyst supported on a porous ?-alumina foam. Reforming approaches include steam reforming and catalytic partial oxidation (CPOX) utilizing either air or pure oxygen as the oxidant. A computational model is developed and utilized to guide the specification of reforming conditions that maximize both CH4 and CO2 conversions. Model predictions are validated with experimental measurements over a wide range of biogas-reforming conditions. Higher reforming temperatures are shown to activate the biogas-borne CO2 to enable significant methane dry-reforming chemistry. Dry reforming minimizes the oxidant-addition needs for effective biogas conversion potentially decreasing the thermal requirements for reactant heating and improving system efficiency. Such high-temperature reforming conditions are prevalent during CPOX with a pure-O2 oxidant. While CPOX-with-O2 reforming is highly exothermic the endothermicity of dry-reforming chemistry can be exploited to ensure that catalyst temperatures do not reach levels which cause catalyst sintering and degradation. SOFCelectrochemical performance under biogas reformate is shown to vary substantially with reforming approach. Cell operation under CPOX-with-O2 reformate is found to be comparable to that under humidified hydrogen.

Danielle M. Murphy; Amy E. Richards; Andrew Colclasure; Wade A. Rosensteel; Neal P. Sullivan

2012-01-01T23:59:59.000Z

79

Synthesis and Stability of a Nanoparticle-Infiltrated Solid Oxide Fuel Cell Electrode  

E-Print Network (OSTI)

Nanoparticle-Infiltrated Solid Oxide Fuel Cell Electrode Talinfiltrated into SOFC (Solid Oxide Fuel Cell) electrodes can

Sholklapper, Tal Z.; Radmilovic, Velimir; Jacobson, Craig P.; Visco, Steven J.; De Jonghe, Lutgard C.

2006-01-01T23:59:59.000Z

80

Solid oxide fuel cell having monolithic core  

DOE Patents (OSTI)

A solid oxide fuel cell is described for electrochemically combining fuel and oxidant for generating galvanic output, wherein the cell core has an array of electrolyte and interconnect walls that are substantially devoid of any composite inert materials for support. Instead, the core is monolithic, where each electrolyte wall consists of thin layers of cathode and anode materials sandwiching a thin layer of electrolyte material therebetween. The electrolyte walls are arranged and backfolded between adjacent interconnect walls operable to define a plurality of core passageways alternately arranged where the inside faces thereof have only the anode material or only the cathode material exposed. Means direct the fuel to the anode-exposed core passageways and means direct the oxidant to the anode-exposed core passageways and means direct the oxidant to the cathode-exposed core passageway; and means also direct the galvanic output to an exterior circuit. Each layer of the electrolyte and interconnect materials is of the order of 0.002 to 0.01 cm thick; and each layer of the cathode and anode materials is of the order of 0.002 to 0.05 cm thick.

Ackerman, J.P.; Young, J.E.

1983-10-12T23:59:59.000Z

Note: This page contains sample records for the topic "oxide fuel fabrication" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


81

Fabrication of carbon-aerogel electrodes for use in phosphoric acid fuel cells .  

E-Print Network (OSTI)

??An experiment was done to determine the ability to fabricate carbon aerogel electrodes for use in a phosphoric acid fuel cell (PAFC). It was found… (more)

Tharp, Ronald S

2005-01-01T23:59:59.000Z

82

Concept for a small, colocated fuel cycle facility for oxide breeder fuels  

SciTech Connect

As part of a United States Department of Energy (USDOE) program to examine innovative liquid-metal reactor (LMR) system designs over the past three years, the Oak Ridge National Laboratory (ORNL) and the Westinghouse Hanford Company (WHC) collaborated on studies of mixed oxide fuel cycle options. A principal effort was an advanced concept for a small integrated fuel cycle colocated with a 1300-MW(e) reactor station. The study provided a scoping design and a basis on which to proceed with implementation of such a facility if future plans so dictate. The facility integrated reprocessing, waste management, and refabrication functions in a single facility of nominal 35-t/year capacity utilizing the latest technology developed in fabrication programs at WHC and in reprocessing at ORNL. The concept was based on many years of work at both sites and extensive design studies of prior years.

Burch, W.D.; Stradley, J.G.; Lerch, R.E.

1987-01-01T23:59:59.000Z

83

Environmental assessment for radioisotope heat source fuel processing and fabrication  

SciTech Connect

DOE has prepared an Environmental Assessment (EA) for radioisotope heat source fuel processing and fabrication involving existing facilities at the Savannah River Site (SRS) near Aiken, South Carolina and the Los Alamos National Laboratory (LANL) near Los Alamos, New Mexico. The proposed action is needed to provide Radioisotope Thermoelectric Generators (RTG) to support the National Aeronautics and Space Administration's (NASA) CRAF and Cassini Missions. Based on the analysis in the EA, DOE has determined that the proposed action does not constitute a major Federal action significantly affecting the quality of the human environment within the meaning of the National Environmental Policy Act (NEPA) of 1969. Therefore, an Environmental Impact Statement is not required. 30 refs., 5 figs.

Not Available

1991-07-01T23:59:59.000Z

84

FUEL CELLS – SOLID OXIDE FUEL CELLS | Gas Distribution  

Science Journals Connector (OSTI)

A uniform distribution of the reactants over the total available electrode surfaces in solid oxide fuel cells (SOFCs) is a prerequisite for the proper operation of the fuel cell. The gas distribution plays a dominant role not only in the current density distribution but also in the temperature distribution over the cell areas and in the stack and modules. Several transport mechanisms for mass transport occurring in the SOFC are introduced and discussed. General flow configurations and structures for the gas distribution at three different levels, i.e., stack/module, cell/tube, and electrode/electrolyte, are discussed for both tubular and planar type cells and illustrated with examples of concentration and temperature profiles.

L.G.J. de Haart; M. Spiller

2009-01-01T23:59:59.000Z

85

Relationship Between Particle and Plasma Properties and Coating Characteristics of Samaria-Doped Ceria Prepared by Atmospheric Plasma Spraying for Use in Solid Oxide Fuel Cells  

Science Journals Connector (OSTI)

Samaria-doped ceria (SDC) has become a promising material for the fabrication of high-performance, intermediate-temperature solid oxide fuel cells (SOFCs). In this study, the in-flight characteristics, such as pa...

Mark Cuglietta; Olivera Kesler

2012-06-01T23:59:59.000Z

86

Solid oxide fuel cell matrix and modules  

DOE Patents (OSTI)

Porous refractory ceramic blocks arranged in an abutting, stacked configuration and forming a three dimensional array provide a support structure and coupling means for a plurality of solid oxide fuel cells (SOFCs). The stack of ceramic blocks is self-supporting, with a plurality of such stacked arrays forming a matrix enclosed in an insulating refractory brick structure having an outer steel layer. The necessary connections for air, fuel, burnt gas, and anode and cathode connections are provided through the brick and steel outer shell. The ceramic blocks are so designed with respect to the strings of modules that by simple and logical design the strings could be replaced by hot reloading if one should fail. The hot reloading concept has not been included in any previous designs. 11 figs.

Riley, B.

1988-04-22T23:59:59.000Z

87

Multi-scale solid oxide fuel cell materials modeling  

Science Journals Connector (OSTI)

Performance and degradation of fuel cell components are discussed in a multi-scale ... paper. Electrochemical reactions in a solid oxide fuel cell occur simultaneously as charge and gas pass ... and cathode to pr...

Ji Hoon Kim; Wing Kam Liu; Christopher Lee

2009-10-01T23:59:59.000Z

88

New materials for intermediate-temperature solid oxide fuel cells to be powered by carbon- and sulfur-containing fuels.  

E-Print Network (OSTI)

??Unlike polymer electrolyte fuel cells, solid-oxide fuel cells (SOFCs) have the potential to use a wide variety of fuels, including hydrocarbons and gasified coal or… (more)

Yang, Lei

2011-01-01T23:59:59.000Z

89

Mathematical Analysis of Planar Solid Oxide Fuel Cells.  

E-Print Network (OSTI)

??The mathematical analysis has been developed by using finite volume method, experimental data from literatures, and solving numerically to predict solid oxide fuel cell performances… (more)

Pramuanjaroenkij, Anchasa

2009-01-01T23:59:59.000Z

90

Ageing of integrated-planar solid Oxide Fuel Cells.  

E-Print Network (OSTI)

??The ageing of Solid Oxide Fuel Cells (SOFCs) is a key problem because of the requirement of 50,000 hours to their lifetime in many applications.… (more)

Almutairi, Ghzzai

2013-01-01T23:59:59.000Z

91

FY 2014 Solid Oxide Fuel Cell Project Selections | Department...  

Office of Environmental Management (EM)

Effects and Degradation in Solid Oxide Fuel Cells: Understanding Transport and Thermodynamics." The goals of this project are to: 1) understand the detailed mechanisms of...

92

Solid Oxide Fuel Cell System Utilizing Syngas from Coal Gasifiers  

Science Journals Connector (OSTI)

Solid Oxide Fuel Cell System Utilizing Syngas from Coal Gasifiers ... The oxidizer is expected to be similar in design to a HRSG duct firing burner (at the inlet of a HRSG). ...

Hossein Ghezel-Ayagh; Stephen Jolly; Dilip Patel; David Stauffer

2013-01-10T23:59:59.000Z

93

Hybrid deposition of thin film solid oxide fuel cells and electrolyzers  

DOE Patents (OSTI)

The use of vapor deposition techniques enables synthesis of the basic components of a solid oxide fuel cell (SOFC); namely, the electrolyte layer, the two electrodes, and the electrolyte-electrode interfaces. Such vapor deposition techniques provide solutions to each of the three critical steps of material synthesis to produce a thin film solid oxide fuel cell (TFSOFC). The electrolyte is formed by reactive deposition of essentially any ion conducting oxide, such as defect free, yttria stabilized zirconia (YSZ) by planar magnetron sputtering. The electrodes are formed from ceramic powders sputter coated with an appropriate metal and sintered to a porous compact. The electrolyte-electrode interface is formed by chemical vapor deposition of zirconia compounds onto the porous electrodes to provide a dense, smooth surface on which to continue the growth of the defect-free electrolyte, whereby a single fuel cell or multiple cells may be fabricated. 8 figs.

Jankowski, A.F.; Makowiecki, D.M.; Rambach, G.D.; Randich, E.

1998-05-19T23:59:59.000Z

94

Hybrid deposition of thin film solid oxide fuel cells and electrolyzers  

DOE Patents (OSTI)

The use of vapor deposition techniques enables synthesis of the basic components of a solid oxide fuel cell (SOFC); namely, the electrolyte layer, the two electrodes, and the electrolyte-electrode interfaces. Such vapor deposition techniques provide solutions to each of the three critical steps of material synthesis to produce a thin film solid oxide fuel cell (TFSOFC). The electrolyte is formed by reactive deposition of essentially any ion conducting oxide, such as defect free, yttria stabilized zirconia (YSZ) by planar magnetron sputtering. The electrodes are formed from ceramic powders sputter coated with an appropriate metal and sintered to a porous compact. The electrolyte-electrode interface is formed by chemical vapor deposition of zirconia compounds onto the porous electrodes to provide a dense, smooth surface on which to continue the growth of the defect-free electrolyte, whereby a single fuel cell or multiple cells may be fabricated.

Jankowski, Alan F. (Livermore, CA); Makowiecki, Daniel M. (Livermore, CA); Rambach, Glenn D. (Livermore, CA); Randich, Erik (Endinboro, PA)

1998-01-01T23:59:59.000Z

95

Hybrid deposition of thin film solid oxide fuel cells and electrolyzers  

DOE Patents (OSTI)

The use of vapor deposition techniques enables synthesis of the basic components of a solid oxide fuel cell (SOFC); namely, the electrolyte layer, the two electrodes, and the electrolyte-electrode interfaces. Such vapor deposition techniques provide solutions to each of the three critical steps of material synthesis to produce a thin film solid oxide fuel cell (TFSOFC). The electrolyte is formed by reactive deposition of essentially any ion conducting oxide, such as defect free, yttria stabilized zirconia (YSZ) by planar magnetron sputtering. The electrodes are formed from ceramic powders sputter coated with an appropriate metal and sintered to a porous compact. The electrolyte-electrode interface is formed by chemical vapor deposition of zirconia compounds onto the porous electrodes to provide a dense, smooth surface on which to continue the growth of the defect-free electrolyte, whereby a single fuel cell or multiple cells may be fabricated.

Jankowski, Alan F. (Livermore, CA); Makowiecki, Daniel M. (Livermore, CA); Rambach, Glenn D. (Livermore, CA); Randich, Erik (Endinboro, PA)

1999-01-01T23:59:59.000Z

96

Solid oxide fuel cell matrix and modules  

DOE Patents (OSTI)

Porous refractory ceramic blocks arranged in an abutting, stacked configuration and forming a three dimensional array provide a support structure and coupling means for a plurality of solid oxide fuel cells (SOFCs). Each of the blocks includes a square center channel which forms a vertical shaft when the blocks are arranged in a stacked array. Positioned within the channel is a SOFC unit cell such that a plurality of such SOFC units disposed within a vertical shaft form a string of SOFC units coupled in series. A first pair of facing inner walls of each of the blocks each include an interconnecting channel hole cut horizontally and vertically into the block walls to form gas exit channels. A second pair of facing lateral walls of each block further include a pair of inner half circular grooves which form sleeves to accommodate anode fuel and cathode air tubes. The stack of ceramic blocks is self-supporting, with a plurality of such stacked arrays forming a matrix enclosed in an insulating refractory brick structure having an outer steel layer. The necessary connections for air, fuel, burnt gas, and anode and cathode connections are provided through the brick and steel outer shell. The ceramic blocks are so designed with respect to the strings of modules that by simple and logical design the strings could be replaced by hot reloading if one should fail. The hot reloading concept has not been included in any previous designs.

Riley, Brian (Willimantic, CT)

1990-01-01T23:59:59.000Z

97

Effect of Natural Gas Fuel Addition on the Oxidation of Fuel Cell Anode Gas  

SciTech Connect

The anode exhaust gas from a fuel cell commonly has a fuel energy density between 15 and 25% that of the fuel supply, due to the incomplete oxidation of the input fuel. This exhaust gas is subsequently oxidized (catalytically or non-catalytically), and the resultant thermal energy is often used elsewhere in the fuel cell process. Alternatively, additional fuel can be added to this stream to enhance the oxidation of the stream, for improved thermal control of the power plant, or to adjust the temperature of the exhaust gas as may be required in other specialty co-generation applications. Regardless of the application, the cost of a fuel cell system can be reduced if the exhaust gas oxidation can be accomplished through direct gas phase oxidation, rather than the usual catalytic oxidation approach. Before gas phase oxidation can be relied upon however, combustor design requirements need to be understood. The work reported here examines the issue of fuel addition, primarily as related to molten-carbonate fuel cell technology. It is shown experimentally that without proper combustor design, the addition of natural gas can readily quench the anode gas oxidation. The Chemkin software routines were used to resolve the mechanisms controlling the chemical quenching. It is found that addition of natural gas to the anode exhaust increases the amount of CH3 radicals, which reduces the concentration of H and O radicals and results in decreased rates of overall fuel oxidation.

Randall S. Gemmen; Edward H. Robey, Jr.

1999-11-01T23:59:59.000Z

98

Fabrication of microfluidic devices with application to membraneless fuel cells.  

E-Print Network (OSTI)

??This thesis is part of an ongoing collaborative research project focused on the development of microstructured enzymatic fuel cells. Both enzymatic fuel cells and co-laminar… (more)

McKechnie, Jon

2009-01-01T23:59:59.000Z

99

Promises and problems with metallic interconnects for reduced temperature solid oxide fuel cells  

E-Print Network (OSTI)

Symposium on Solid Oxide Fuel Cells (SOFC-VI) ed. S. C.FOR REDUCED TEMPERATURE SOLID OXIDE FUEL CELLS Peggy Y. Hou,for low temperature solid oxide fuel cell is discussed in

Hou, Peggy Y.; Huang, Keqin; Bakker, Wate T.

1999-01-01T23:59:59.000Z

100

Rapid thermal cycling of metal-supported solid oxide fuel cell membranes  

E-Print Network (OSTI)

effect of pressure on solid oxide fuel cell performance," inand flat plate solid oxide fuel cells," in Proceedings ofSymposium on Solid Oxide Fuel Cells. Electrochem. Soc. 1993,

Matus, Yuriy B.; De Jonghe, Lutgard C.; Jacobson, Craig P.; Visco, Steven J.

2004-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "oxide fuel fabrication" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


101

Assured Fuel Supply: Potential Conversion and Fabrication Bottlenecks  

E-Print Network (OSTI)

to nuclear fuel. These efforts include: · The Putin Initiative to create a multinational enrichment center

102

Fabrication and Testing of Full-Length Single-Cell Externally Fueled Converters for Thermionic Reactors  

SciTech Connect

Paper presented at the 29th IECEC in Monterey, CA in August 1994. The present paper describes the fabrication and testing of full-length prototypcial converters, both unfueled and fueled, and presents parametric results of electrically heated tests.

Schock, Alfred

1995-08-01T23:59:59.000Z

103

Licensing issues associated with the use of mixed-oxide fuel in US commercial nuclear reactors  

SciTech Connect

On January 14, 1997, the Department of Energy, as part of its Record of Decision on the storage and disposition of surplus nuclear weapons materials, committed to pursue the use of excess weapons-usable plutonium in the fabrication of mixed-oxide (MOX) fuel for consumption in existing commercial nuclear power plants. Domestic use of MOX fuel has been deferred since the late 1970s, principally due to nuclear proliferation concerns. This report documents a review of past and present literature (i.e., correspondence, reports, etc.) on the domestic use of MOX fuel and provides discussion on the technical and regulatory issues that must be addressed by DOE (and the utility/consortia selected by DOE to effect the MOX fuel consumption strategy) in obtaining approval from the Nuclear Regulatory Commission to use MOX fuel in one or a group of existing commercial nuclear power plants.

Williams, D.L. Jr.

1997-04-01T23:59:59.000Z

104

The burnup dependence of light water reactor spent fuel oxidation  

SciTech Connect

Over the temperature range of interest for dry storage or for placement of spent fuel in a permanent repository under the conditions now being considered, UO{sub 2} is thermodynamically unstable with respect to oxidation to higher oxides. The multiple valence states of uranium allow for the accommodation of interstitial oxygen atoms in the fuel matrix. A variety of stoichiometric and nonstoichiometric phases is therefore possible as the fuel oxidizers from UO{sub 2} to higher oxides. The oxidation of UO{sub 2} has been studied extensively for over 40 years. It has been shown that spent fuel and unirradiated UO{sub 2} oxidize via different mechanisms and at different rates. The oxidation of LWR spent fuel from UO{sub 2} to UO{sub 2.4} was studied previously and is reasonably well understood. The study presented here was initiated to determine the mechanism and rate of oxidation from UO{sub 2.4} to higher oxides. During the early stages of this work, a large variability in the oxidation behavior of samples oxidized under nearly identical conditions was found. Based on previous work on the effect of dopants on UO{sub 2} oxidation and this initial variability, it was hypothesized that the substitution of fission product and actinide impurities for uranium atoms in the spent fuel matrix was the cause of the variable oxidation behavior. Since the impurity concentration is roughly proportional to the burnup of a specimen, the oxidation behavior of spent fuel was expected to be a function of both temperature and burnup. This report (1) summarizes the previous oxidation work for both unirradiated UO{sub 2} and spent fuel (Section 2.2) and presents the theoretical basis for the burnup (i.e., impurity concentration) dependence of the rate of oxidation (Sections 2.3, 2.4, and 2.5), (2) describes the experimental approach (Section 3) and results (Section 4) for the current oxidation tests on spent fuel, and (3) establishes a simple model to determine the activation energies associated with spent fuel oxidation (Section 5).

Hanson, B.D.

1998-07-01T23:59:59.000Z

105

Interim Action Determination Flexible Manufacturing Capability for the Mixed Fuel Fabrication Facility (MFFF)  

NLE Websites -- All DOE Office Websites (Extended Search)

Flexible Manufacturing Capability for the Mixed Fuel Fabrication Facility (MFFF) Flexible Manufacturing Capability for the Mixed Fuel Fabrication Facility (MFFF) The Department of Energy (DOE) is preparing the Surplus Plutonium Disposition Supplemental Environmental Impact Statement (SPD SEIS), DOE/EIS-0283-S2. DOE is evaluating, among many other things, the environmental impacts of any design and operations changes to the MFFF, which is under construction at the Savannah River Site near Aiken, South Carolina. DOE

106

Interim Action Determination Flexible Manufacturing Capability for the Mixed Fuel Fabrication Facility (MFFF)  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Flexible Manufacturing Capability for the Mixed Fuel Fabrication Facility (MFFF) Flexible Manufacturing Capability for the Mixed Fuel Fabrication Facility (MFFF) The Department of Energy (DOE) is preparing the Surplus Plutonium Disposition Supplemental Environmental Impact Statement (SPD SEIS), DOE/EIS-0283-S2. DOE is evaluating, among many other things, the environmental impacts of any design and operations changes to the MFFF, which is under construction at the Savannah River Site near Aiken, South Carolina. DOE

107

Nanostructured Solid Oxide Fuel Cell Electrodes  

SciTech Connect

The ability of Solid Oxide Fuel Cells (SOFC) to directly and efficiently convert the chemical energy in hydrocarbon fuels to electricity places the technology in a unique and exciting position to play a significant role in the clean energy revolution. In order to make SOFC technology cost competitive with existing technologies, the operating temperatures have been decreased to the range where costly ceramic components may be substituted with inexpensive metal components within the cell and stack design. However, a number of issues have arisen due to this decrease in temperature: decreased electrolyte ionic conductivity, cathode reaction rate limitations, and a decrease in anode contaminant tolerance. While the decrease in electrolyte ionic conductivities has been countered by decreasing the electrolyte thickness, the electrode limitations have remained a more difficult problem. Nanostructuring SOFC electrodes addresses the major electrode issues. The infiltration method used in this dissertation to produce nanostructure SOFC electrodes creates a connected network of nanoparticles; since the method allows for the incorporation of the nanoparticles after electrode backbone formation, previously incompatible advanced electrocatalysts can be infiltrated providing electronic conductivity and electrocatalysis within well-formed electrolyte backbones. Furthermore, the method is used to significantly enhance the conventional electrode design by adding secondary electrocatalysts. Performance enhancement and improved anode contamination tolerance are demonstrated in each of the electrodes. Additionally, cell processing and the infiltration method developed in conjunction with this dissertation are reviewed.

Sholklapper, Tal Zvi

2007-12-15T23:59:59.000Z

108

Solid Oxide Fuel Cell Balance of Plant and Stack Component Integration...  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

Solid Oxide Fuel Cell Balance of Plant and Stack Component Integration Solid Oxide Fuel Cell Balance of Plant and Stack Component Integration Presentation by Acumentrics...

109

Electrode electrolyte interlayers containing cerium oxide for electrochemical fuel cells  

DOE Patents (OSTI)

An electrochemical cell is made having a porous fuel electrode (16) and a porous air electrode (13), with solid oxide electrolyte (15) therebetween, where the air electrode surface opposing the electrolyte has a separate, attached, dense, continuous layer (14) of a material containing cerium oxide, and where electrolyte (16) contacts the continuous oxide layer (14), without contacting the air electrode (13).

Borglum, Brian P. (Edgewood, PA); Bessette, Norman F. (N. Huntingdon, PA)

2000-01-01T23:59:59.000Z

110

The Oxidation of Ferritic Stainless Steels in Simulated Solid-Oxide Fuel-Cell Atmospheres  

Science Journals Connector (OSTI)

The cyclic oxidation of a variety of chromia-forming ferritic stainless steels has been studied in the temperature range 700–900°C in atmospheres relevant to solid-oxide fuel-cell operation. The most detriment...

J. E. Hammer; S. J. Laney; R. W. Jackson; K. Coyne; F. S. Pettit…

2007-02-01T23:59:59.000Z

111

Economic Analysis on Direct Use of Spent Pressurized Water Reactor Fuel in CANDU Reactors - I: DUPIC Fuel Fabrication Cost  

SciTech Connect

A preliminary conceptual design of a Direct Use of spent Pressurized water reactor (PWR) fuel In Canada deuterium uranium (CANDU) reactors (DUPIC) fuel fabrication plant was studied, which annually converts spent PWR fuel of 400 tonnes heavy element (HE) into CANDU fuel. The capital and operating costs were estimated from the viewpoint of conceptual design. Assuming that the annual discount rate is 5% during the construction (5 yr) and operation period (40 yr) and contingency is 25% of the capital cost, the levelized unit cost (LUC) of DUPIC fuel fabrication was estimated to be 616 $/kg HE, which is mostly governed by annual operation and maintenance costs that correspond to 63% of LUC. Among the operation and maintenance cost components being considered, the waste disposal cost has the dominant effect on LUC ({approx}49%). From sensitivity analyses of production capacity, discount rate, and contingency, it was found that the production capacity of the plant is the major parameter that affects the LUC.

Choi, Hangbok; Ko, Won Il; Yang, Myung Seung [Korea Atomic Energy Research Institute (Korea, Republic of)

2001-05-15T23:59:59.000Z

112

A microfluidic microbial fuel cell fabricated by soft lithography Fang Qian a,b,  

E-Print Network (OSTI)

A microfluidic microbial fuel cell fabricated by soft lithography Fang Qian a,b, , Zhen He c microfluidic microbial fuel cell (MFC) platform built by soft-lithography tech- niques. The MFC design includes a unique sub-5 lL polydimethylsiloxane soft chamber featuring carbon cloth electrodes and microfluidic

113

Proceedings of the Lucerne Fuel Cell Forum 2006 European Solid Oxide Fuel Cell Forum, 3-7 July 2006  

E-Print Network (OSTI)

Proceedings of the Lucerne Fuel Cell Forum 2006 7th European Solid Oxide Fuel Cell Forum, 3-7 July Uncertainties in our understanding of the oxygen reduction mechanism (ORR) at solid oxide fuel cell (SOFC studies have shown that cathodic or anodic dc polarization of the solid oxide fuel cell oxygen electrodes

Yildiz, Bilge

114

An integrated approach for the verification of fresh mixed oxide fuel (MOX) assemblies at light water reactor MOX recycle reactors  

SciTech Connect

This paper presents an integrated approach for the verification of mixed oxide (MOX) fuel assemblies prior to their being loaded into the reactor. There is a coupling of the verification approach that starts at the fuel fabrication plant and stops with the transfer of the assemblies into the thermal reactor. The key measurement points are at the output of the fuel fabrication plant, the receipt at the reactor site, and the storage in the water pool as fresh fuel. The IAEA currently has the capability to measure the MOX fuel assemblies at the output of the fuel fabrication plants using a passive neutron coincidence counting systems of the passive neutron collar (PNCL) type. Also. at the MOX reactor pool, the underwater coincidence counter (UWCC) has been developed to measure the MOX assemblies in the water. The UWCC measurement requires that the fuel assembly be lifted about two meters up in the storage rack to avoid interference from the fuel that is stored in the rack. This paper presents a new method to verify the MOX fuel assemblies that are in the storage rack without the necessity of moving the fuel. The detector system is called the Underwater MOX Verification System (UMVS). The integration and relationship of the three measurements systems is described.

Menlove, Howard O [Los Alamos National Laboratory; Lee, Sang - Yoon [Los Alamos National Laboratory

2009-01-01T23:59:59.000Z

115

Stack configurations for tubular solid oxide fuel cells  

DOE Patents (OSTI)

A fuel cell unit includes an array of solid oxide fuel cell tubes having porous metallic exterior surfaces, interior fuel cell layers, and interior surfaces, each of the tubes having at least one open end; and, at least one header in operable communication with the array of solid oxide fuel cell tubes for directing a first reactive gas into contact with the porous metallic exterior surfaces and for directing a second reactive gas into contact with the interior surfaces, the header further including at least one busbar disposed in electrical contact with at least one surface selected from the group consisting of the porous metallic exterior surfaces and the interior surfaces.

Armstrong, Timothy R. (Clinton, TN); Trammell, Michael P. (Clinton, TN); Marasco, Joseph A. (Kingston, TN)

2010-08-31T23:59:59.000Z

116

Fuel electrode containing pre-sintered nickel/zirconia for a solid oxide fuel cell  

DOE Patents (OSTI)

A fuel cell structure (2) is provided, having a pre-sintered nickel-zirconia fuel electrode (6) and an air electrode (4), with a ceramic electrolyte (5) disposed between the electrodes, where the pre-sintered fuel electrode (6) contains particles selected from the group consisting of nickel oxide, cobalt and cerium dioxide particles and mixtures thereof, and titanium dioxide particles, within a matrix of yttria-stabilized zirconia and spaced-apart filamentary nickel strings having a chain structure, and where the fuel electrode can be sintered to provide an active solid oxide fuel cell.

Ruka, Roswell J. (Pittsburgh, PA); Vora, Shailesh D. (Monroeville, PA)

2001-01-01T23:59:59.000Z

117

An Octane-Fueled Solid Oxide Fuel Cell  

Science Journals Connector (OSTI)

...for the adoption of fuel cells for applications...not only reduces fuel consumption but also reduces...emission. Although fuel cells can achieve efficiencies...internal combustion engine, and H 2 is more...is, gasoline and diesel, has not been successful...

Zhongliang Zhan; Scott A. Barnett

2005-05-06T23:59:59.000Z

118

Graphene oxide/hydroxyapatite composite coatings fabricated by electrophoretic nanotechnology for  

E-Print Network (OSTI)

Graphene oxide/hydroxyapatite composite coatings fabricated by electrophoretic nanotechnology April 2013 Accepted 27 September 2013 Available online 8 October 2013 A B S T R A C T Graphene oxide (GO and uncoated Ti substrate. Ă? 2013 Elsevier Ltd. All rights reserved. 1. Introduction Graphene oxide (GO

Zheng, Yufeng

119

Oxidation Protection of Uranium Nitride Fuel using Liquid Phase Sintering  

SciTech Connect

Two methods are proposed to increase the oxidation resistance of uranium nitride (UN) nuclear fuel. These paths are: (1) Addition of USi{sub x} (e.g. U3Si2) to UN nitride powder, followed by liquid phase sintering, and (2) 'alloying' UN nitride with various compounds (followed by densification via Spark Plasma Sintering or Liquid Phase Sintering) that will greatly increase oxidation resistance. The advantages (high thermal conductivity, very high melting point, and high density) of nitride fuel have long been recognized. The sodium cooled BR-10 reactor in Russia operated for 18 years on uranium nitride fuel (UN was used as the driver fuel for two core loads). However, the potential advantages (large power up-grade, increased cycle lengths, possible high burn-ups) as a Light Water Reactor (LWR) fuel are offset by uranium nitride's extremely low oxidation resistance (UN powders oxidize in air and UN pellets decompose in hot water). Innovative research is proposed to solve this problem and thereby provide an accident tolerant LWR fuel that would resist water leaks and high temperature steam oxidation/spalling during an accident. It is proposed that we investigate two methods to increase the oxidation resistance of UN: (1) Addition of USi{sub x} (e.g. U{sub 3}Si{sub 2}) to UN nitride powder, followed by liquid phase sintering, and (2) 'alloying' UN nitride with compounds (followed by densification via Spark Plasma Sintering) that will greatly increase oxidation resistance.

Dr. Paul A. Lessing

2012-03-01T23:59:59.000Z

120

Fabrication of Micro-Orifices for Diesel Fuel Injectors  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

G. Fenske, J. Wang, and E. El- Hannouny (ANL), R Schaefer and F. Hamady (NVFEL) US DOE - Vehicle Technologies Propulsion Materials Jerry Gibbs Fabrication of Micro-orifices for...

Note: This page contains sample records for the topic "oxide fuel fabrication" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


121

FY 2014 Solid Oxide Fuel Cell Project Selections  

Energy.gov (U.S. Department of Energy (DOE))

In FY 2014, nine research projects focused on advancing the reliability, robustness, and endurance of solid oxide fuel cells (SOFC) have been selected for funding by Office of Fossil Energy’s...

122

Perspectives on the metallic interconnects for solid oxide fuel cells  

Science Journals Connector (OSTI)

The various stages and progress in the development of interconnect materials for solid oxide fuel cells (SOFCs) over the last two decades are reviewed. The criteria for the application of materials as intercon...

Wei-zhong Zhu; Mi Yan

2004-12-01T23:59:59.000Z

123

Solid Oxide Fuel Cell and Power System Development at PNNL |...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

and Power System Development at PNNL Solid Oxide Fuel Cell and Power System Development at PNNL Presented at the DOE-DOD Shipboard APU Workshop on March 29, 2011....

124

Nanostructured thin films for solid oxide fuel cells  

E-Print Network (OSTI)

The goals of this work were to synthesize high performance perovskite based thin film solid oxide fuel cell (TF-SOFC) cathodes by pulsed laser deposition (PLD), to study the structural, electrical and electrochemical properties of these cathodes...

Yoon, Jongsik

2009-05-15T23:59:59.000Z

125

Microstructural Examination to Aid in Understanding Friction Bonding Fabrication Technique for Monolithic Nuclear Fuel  

SciTech Connect

Monolithic nuclear fuel is currently being developed for use in research reactors, and friction bonding (FB) is a technique being developed to help in this fuel’s fabrication. Since both FB and monolithic fuel are new concepts, research is needed to understand the impact of varying FB fabrication parameters on fuel plate characteristics. This thesis research provides insight into the FB process and its application to the monolithic fuel design by recognizing and understanding the microstructural effects of varying fabrication parameters (a) FB tool load, and (b) FB tool face alloy. These two fabrication parameters help drive material temperature during fabrication, and thus the material properties, bond strength, and possible formation of interface reaction layers. This study analyzed temperatures and tool loads measured during those FB processes and examined microstructural characteristics of materials and bonds in samples taken from the resulting fuel plates. This study shows that higher tool load increases aluminum plasticization and forging during FB, and that the tool face alloy helps determine the tool’s heat extraction efficacy. The study concludes that successful aluminum bonds can be attained in fuel plates using a wide range of FB tool loads. The range of tool loads yielding successful uranium-aluminum bonding was not established, but it was demonstrated that such bonding can be attained with FB tool load of 48,900 N (11,000 lbf) when using a FB tool faced with a tungsten alloy. This tool successfully performed FB, and with better results than tools faced with other materials. Results of this study correlate well with results reported for similar aluminum bonding techniques. This study’s results also provide support and validation for other nuclear fuel development studies and conclusions. Recommendations are offered for further research.

Karen L. Shropshire

2008-04-01T23:59:59.000Z

126

The Role of Friction Stir Welding in Nuclear Fuel Plate Fabrication  

SciTech Connect

The friction bonding process combines desirable attributes of both friction stir welding and friction stir processing. The development of the process is spurred on by the need to fabricate thin, high density, reduced enrichment fuel plates for nuclear research reactors. The work seeks to convert research and test reactors currently operating on highly enriched uranium fuel to operate on low enriched uranium fuel without significant loss in reactor performance, safety characteristics, or significant increase in cost. In doing so, the threat of global nuclear material proliferation will be reduced. Feasibility studies performed on the process show that this is a viable option for mass production of plate-type nuclear fuel. Adapting the friction stir weld process for nuclear fuel fabrication has resulted in the development of several unique ideas and observations. Preliminary results of this adaptation and process model development are discussed.

D Burkes; P Medvedev; M Chapple; A Amritkar; P Wells; I Charit

2009-02-01T23:59:59.000Z

127

Risk analysis of shipping plutonium pits and mixed oxide fuel  

E-Print Network (OSTI)

, one possible option that has been identified for disposition of excess U.S. weapons plutonium is the transformation into mixed oxide (MOX) fuel, that then would be used as fuel in a commercial nuclear power plant. Any such process will involve...

Caldwell, Amy Baker

2012-06-07T23:59:59.000Z

128

Mechanical modeling of porous oxide fuel pellet A Test Problem  

SciTech Connect

A poro-elasto-plastic material model has been developed to capture the response of oxide fuels inside the nuclear reactors under operating conditions. Behavior of the oxide fuel and variation in void volume fraction under mechanical loading as predicted by the developed model has been reported in this article. The significant effect of void volume fraction on the overall stress distribution of the fuel pellet has also been described. An important oxide fuel issue that can have significant impact on the fuel performance is the mechanical response of oxide fuel pellet and clad system. Specifically, modeling the thermo-mechanical response of the fuel pellet in terms of its thermal expansion, mechanical deformation, swelling due to void formation and evolution, and the eventual contact of the fuel with the clad is of significant interest in understanding the fuel-clad mechanical interaction (FCMI). These phenomena are nonlinear and coupled since reduction in the fuel-clad gap affects thermal conductivity of the gap, which in turn affects temperature distribution within the fuel and the material properties of the fuel. Consequently, in order to accurately capture fuel-clad gap closure, we need to account for fuel swelling due to generation, retention, and evolution of fission gas in addition to the usual thermal expansion and mechanical deformation. Both fuel chemistry and microstructure also have a significant effect on the nucleation and growth of fission gas bubbles. Fuel-clad gap closure leading to eventual contact of the fuel with the clad introduces significant stresses in the clad, which makes thermo-mechanical response of the clad even more relevant. The overall aim of this test problem is to incorporate the above features in order to accurately capture fuel-clad mechanical interaction. Because of the complex nature of the problem, a series of test problems with increasing multi-physics coupling features, modeling accuracy, and complexity are defined with the objective of accurate simulation of fuel-clad mechanical interaction subjected to a wide-range of thermomechanical stimuli.

Nukala, Phani K [ORNL; Barai, Pallab [ORNL; Simunovic, Srdjan [ORNL; Ott, Larry J [ORNL

2009-10-01T23:59:59.000Z

129

Solid Oxide Fuel Cell System (SOFC) Technology R&D Needs (Presentation...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Solid Oxide Fuel Cell System (SOFC) Technology R&D Needs (Presentation) Solid Oxide Fuel Cell System (SOFC) Technology R&D Needs (Presentation) Presented at the DOE Fuel Cell...

130

Fuel cell power supply with oxidant and fuel gas switching  

DOE Patents (OSTI)

This invention relates to a fuel cell vehicular power plant. Fuel for the fuel stack is supplied by a hydrocarbon (methanol) catalytic cracking reactor and CO shift reactor. A water electrolysis subsystem is associated with the stack. During low power operation part of the fuel cell power is used to electrolyze water with hydrogen and oxygen electrolysis products being stored in pressure vessels. During peak power intervals, viz, during acceleration or start-up, pure oxygen and pure hydrogen from the pressure vessel are supplied as the reaction gases to the cathodes and anodes in place of air and methanol reformate. This allows the fuel cell stack to be sized for normal low power/air operation but with a peak power capacity several times greater than that for normal operation.

McElroy, James F. (Hamilton, MA); Chludzinski, Paul J. (Swampscott, MA); Dantowitz, Philip (Peabody, MA)

1987-01-01T23:59:59.000Z

131

Fuel cell power supply with oxidant and fuel gas switching  

DOE Patents (OSTI)

This invention relates to a fuel cell vehicular power plant. Fuel for the fuel stack is supplied by a hydrocarbon (methanol) catalytic cracking reactor and CO shift reactor. A water electrolysis subsystem is associated with the stack. During low power operation part of the fuel cell power is used to electrolyze water with hydrogen and oxygen electrolysis products being stored in pressure vessels. During peak power intervals, viz, during acceleration or start-up, pure oxygen and pure hydrogen from the pressure vessel are supplied as the reaction gases to the cathodes and anodes in place of air and methanol reformate. This allows the fuel cell stack to be sized for normal low power/air operation but with a peak power capacity several times greater than that for normal operation. 2 figs.

McElroy, J.F.; Chludzinski, P.J.; Dantowitz, P.

1987-04-14T23:59:59.000Z

132

An improved characterization method for international accountancy measurements of fresh and irradiated mixed oxide (MOX) fuel: helping achieve continual monitoring and safeguards through the fuel cycle  

SciTech Connect

Nuclear fuel accountancy measurements are conducted at several points through the nuclear fuel cycle to ensure continuity of knowledge (CofK) of special nuclear material (SNM). Non-destructive assay (NDA) measurements are performed on fresh fuel (prior to irradiation in a reactor) and spent nuclear fuel (SNF) post-irradiation. We have developed a fuel assembly characterization system, based on the novel concept of 'neutron fingerprinting' with multiplicity signatures to ensure detailed CofK of nuclear fuel through the entire fuel cycle. The neutron fingerprint in this case is determined by the measurement of the various correlated neutron signatures, specific to fuel isotopic composition, and therefore offers greater sensitivity to variations in fissile content among fuel assemblies than other techniques such as gross neutron counting. This neutron fingerprint could be measured at the point of fuel dispatch (e.g. from a fuel fabrication plant prior to irradiation, or from a reactor site post-irradiation), monitored during transportation of the fuel assembly, and measured at a subsequent receiving site (e.g. at the reactor site prior to irradiation, or reprocessing facility post-irradiation); this would confirm that no unexpected changes to the fuel composition or amount have taken place during transportation and/ or reactor operations. Changes may indicate an attempt to divert material for example. Here, we present the current state of the practice of fuel measurements for both fresh mixed oxide (MOX) fuel and SNF (both MOX and uranium dioxide). This is presented in the framework of international safeguards perspectives from the US and UK. We also postulate as to how the neutron fingerprinting concept could lead to improved fuel characterization (both fresh MOX and SNF) resulting in: (a) assured CofK of fuel across the nuclear fuel cycle, (b) improved detection of SNM diversion, and (c) greater confidence in safeguards of SNF transportation.

Evans, Louise G [Los Alamos National Laboratory; Croft, Stephen [Los Alamos National Laboratory; Swinhoe, Martyn T [Los Alamos National Laboratory; Tobin, S. J. [Los Alamos National Laboratory; Menlove, H. O. [Los Alamos National Laboratory; Schear, M. A. [Los Alamos National Laboratory; Worrall, Andrew [U.K. NNL

2011-01-13T23:59:59.000Z

133

An improved characterization method for international accountancy measurements of fresh and irradiated mixed oxide (MOX) fuel: helping achieve continual monitoring and safeguards through the fuel cycle  

SciTech Connect

Nuclear fuel accountancy measurements are conducted at several points through the nuclear fuel cycle to ensure continuity of knowledge (CofK) of special nuclear material (SNM). Non-destructive assay (NDA) measurements are performed on fresh fuel (prior to irradiation in a reactor) and spent nuclear fuel (SNF) post-irradiation. We have developed a fuel assembly characterization system, based on the novel concept of 'neutron fingerprinting' with multiplicity signatures to ensure detailed CofK of nuclear fuel through the entire fuel cycle. The neutron fingerprint in this case is determined by the measurement of the various correlated neutron signatures, specific to fuel isotopic composition, and therefore offers greater sensitivity to variations in fissile content among fuel assemblies than other techniques such as gross neutron counting. This neutron fingerprint could be measured at the point of fuel dispatch (e.g. from a fuel fabrication plant prior to irradiation, or from a reactor site post-irradiation), monitored during transportation of the fuel assembly, and measured at a subsequent receiving site (e.g. at the reactor site prior to irradiation, or reprocessing facility post-irradiation); this would confirm that no unexpected changes to the fuel composition or amount have taken place during transportation and/or reactor operations. Changes may indicate an attempt to divert material for example. Here, we present the current state of the practice of fuel measurements for both fresh mixed oxide (MOX) fuel and SNF (both MOX and uranium dioxide). This is presented in the framework of international safeguards perspectives from the US and UK. We also postulate as to how the neutron fingerprinting concept could lead to improved fuel characterization (both fresh MOX and SNF) resulting in: (a) assured CofK of fuel across the nuclear fuel cycle, (b) improved detection of SNM diversion, and (c) greater confidence in safeguards of SNF transportation.

Evans, Louise G [Los Alamos National Laboratory; Croft, Stephen [Los Alamos National Laboratory; Swinhoe, Martyn T [Los Alamos National Laboratory; Tobin, S. J. [Los Alamos National Laboratory; Boyer, B. D. [Los Alamos National Laboratory; Menlove, H. O. [Los Alamos National Laboratory; Schear, M. A. [Los Alamos National Laboratory; Worrall, Andrew [U.K., NNL

2010-11-24T23:59:59.000Z

134

Direct oxidation of hydrocarbons in a solid oxide fuel cell. I. Methane oxidation  

SciTech Connect

The performance of Cu cermets as anodes for the direct oxidation of CH{sub 4} in solid oxide fuel cells was examined. Mixtures of Cu and yttria-stabilized zirconia (YAZ) were found to give similar performance to Ni-YSZ cermets when H{sub 2} was used as the fuel, but did not deactivate in dry CH{sub 4}. While Cu-YSZ was essentially inert to methane, the addition of ceria to the anode gave rise to reasonable power densities and stable operation over a period of at least 3 days. Proof of direct oxidation of CH{sub 4} came from chemical analysis of the products leaving the cell. The major carbon-containing product was CO{sub 2}, with only traces of CO observed, and there was excellent agreement between the actual cell current and that predicted by the methane conversion. These results demonstrate that direct, electrocatalytic oxidation of dry methane is possible, with reasonable performance.

Park, S.; Craciun, R.; Vohs, J.M.; Gorte, R.J.

1999-10-01T23:59:59.000Z

135

THE IMPACT OF VARIOUS OXIDIZERS ON THE OVERALL PERFORMACE OF A DIRECT FLAME SOLID OXIDE FUEL CELL.  

E-Print Network (OSTI)

??The power output of a direct-flame solid oxide fuel cell (SOFC) was studied using hydrogen (H2) as the fuel for the flame and various oxidizers,… (more)

Donadio, Nicholas

2010-01-01T23:59:59.000Z

136

ELECTRODE DEVELOPMENT FOR REVERSIBLE SOLID OXIDE FUEL CELLS  

SciTech Connect

The reversibility of the electrodes for a solid oxide fuel cell with an yttria-stabilized zirconia (YSZ) electrolyte was examined using electrochemical impedance spectroscopy and current interrupt methods. The fuel electrodes were nickel/zirconia cermet and lanthanum-doped strontium titanate/doped ceria composites. The air electrodes were lanthanum strontium ferrite (LSF) and lanthanum strontium copper ferrite (LSCuF). Under the experimental conditions studied all four electrodes were able to operate in both the fuel cell and electrolyzer modes. The titanate/ceria fuel electrode performed substantially better in the electrolyzer mode than state-of-art Ni-YSZ. Moreover, it showed slightly higher activity for water electrolysis as compared to hydrogen oxidation. Air electrodes were less active in the electrolyzer than fuel cell modes. LSF typically provided higher overpotential losses in both modes than copper-substituted LSF. Changes in the defect chemistry of electrode materials under cathodic and anodic polarization are discussed.

Marina, Olga A.; Coffey, Greg W.; Pederson, Larry R.; Rieke, Peter C.; Thomsen, Ed C.; Williams, Mark C.

2004-08-06T23:59:59.000Z

137

Neutron Sciences - Electrode Material for Solid-oxide Fuel Cells  

NLE Websites -- All DOE Office Websites (Extended Search)

Theory meets experiment: structure-property relationships in an electrode Theory meets experiment: structure-property relationships in an electrode material for solid-oxide fuel cells Research Contact: Ana B. Munoz-Garcia December 2012, Written by Agatha Bardoel Fuel cell technology is one potentially very efficient and environmentally friendly way to convert the chemical energy of fuels into electricity. Solid-oxide fuel cells (SOFCs) can convert a wide variety of fuels with simpler, cheaper designs than those used in liquid electrolyte cells. Using the Powder Diffractometer at the Spallation Neutron Source, researchers experimentally characterized the promising new SOFC electrode material strontium iron molybdenum oxide─Sr2Fe1.5Mo0.5O6-δ (SFMO). Combining the experimental results with insights from theory showed that the crystal structure is distorted from the ideal cubic simple perovskite

138

RADIATION DOSE ASPECTS IN THE HANDLING OF EMERGING NUCLEAR FUELS  

Science Journals Connector (OSTI)

......Prot. (2008) 28:161. 15 NUREG. Standard review plan for the review of an application for a Mixed Oxide (MOX) fuel...fabrication facility. (2000) NUREG-1718, US Nuclear Regulatory Commission. 16 IAEA. Safety of uranium fuel fabrication......

G. Nicolaou

2014-02-01T23:59:59.000Z

139

MOX Fabrication Isolation Considerations  

SciTech Connect

This document provides a technical position on the preferred level of isolation to fabricate demonstration quantities of mixed oxide transmutation fuels. The Advanced Fuel Cycle Initiative should design and construct automated glovebox fabrication lines for this purpose. This level of isolation adequately protects the health and safety of workers and the general public for all mixed oxide (and other transmutation fuel) manufacturing efforts while retaining flexibility, allowing parallel development and setup, and minimizing capital expense. The basis regulations, issues, and advantages/disadvantages of five potential forms of isolation are summarized here as justification for selection of the preferred technical position.

Eric L. Shaber; Bradley J Schrader

2005-08-01T23:59:59.000Z

140

Literature on fabrication of tungsten for application in pyrochemical processing of spent nuclear fuels  

SciTech Connect

The pyrochemical processing of nuclear fuels requires crucibles, stirrers, and transfer tubing that will withstand the temperature and the chemical attack from molten salts and metals used in the process. This report summarizes the literature that pertains to fabrication (joining, chemical vapor deposition, plasma spraying, forming, and spinning) is the main theme. This report also summarizes a sampling of literature on molbdenum and the work previously performed at Argonne National Laboratory on other container materials used for pyrochemical processing of spent nuclear fuels.

Edstrom, C.M.; Phillips, A.G.; Johnson, L.D.; Corle, R.R.

1980-10-11T23:59:59.000Z

Note: This page contains sample records for the topic "oxide fuel fabrication" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


141

Enhanced Power Stability for Proton Conducting Solid Oxides Fuel Cells  

SciTech Connect

In order to provide the basis for a rational approach to improving the performance of Y-doped BaZrO{sub 3} electrolytes for proton conducting ceramic fuel cells, we carried out a series of coupled computational and experimental studies to arrive at a consensus view of the characteristics affecting the proton conductivity of these systems. The computational part of the project developed a practical first principles approach to predicting the proton mobility as a function of temperature and doping for polycrystalline systems. This is a significant breakthrough representing the first time that first principles methods have been used to study diffusion across grain boundaries in such systems. The basis for this breakthrough was the development of the ReaxFF reactive force field that accurately describes the structure and energetics of Y-doped BaZrO{sub 3} as the proton hops from site to site. The ReaxFF parameters are all derived from an extensive set of quantum mechanics calculations on various clusters, two dimensionally infinite slabs, and three dimensionally infinite periodic systems for combinations of metals, metal alloys, metal oxides, pure and Y-doped BaZrO{sub 3}, including chemical reaction pathways and proton transport pathways, structures. The ReaxFF force field enables molecular dynamics simulations to be carried out quickly for systems with {approx} 10,000 atoms rather than the {approx}100 or so practical for QM. The first 2.5 years were spent on developing and validating the ReaxFF and we have only had an opportunity to apply these methods to only a few test cases. However these simulations lead to transport properties (diffusion coefficients and activation energy) for multi-granular systems in good agreement with current experimental results. Now that we have validated the ReaxFF for diffusion across grain boundaries, we are in the position of being able to use computation to explore strategies to improve the diffusion of protons across grain boundaries, which both theory and experiment agree is the cause of the low conductivity of multi-granular systems. Our plan for a future project is to use the theory to optimize the additives and processing conditions and following this with experiment on the most promising systems. The experimental part of this project focused on improving the synthetic techniques for controlling the grain size and making measurements on the properties of these systems as a function of doping of impurities and of process conditions. A significant attention was paid to screening potential cathode materials (transition metal perovskites) and anode electrocatalysts (metals) for reactivity with Y-doped BaZrO{sub 3}, fabrication compatibility, and chemical stability in fuel cell environment. A robust method for fabricating crack-free thin membranes, as well as methods for sealing anode and cathode chambers, have been successfully developed. Our Pt|BYZ|Pt fuel cell, with a 100 {micro}m thick Y-doped BaZrO{sub 3} electrolyte layer, demonstrates the peak power density and short circuit current density of 28 mW/cm{sup 2} and 130mA/cm{sup 2}, respectively. These are the highest values of this type of fuel cell. All of these provide the basis for a future project in which theory and computation are combined to develop modified ceramic electrolytes capable of both high proton conductivity and excellent mechanical and chemical stability.

Boris Merinov; William A. Goddard III; Sossina Haile; Adri van Duin; Peter Babilo; Sang Soo Han

2005-12-29T23:59:59.000Z

142

Analysis of measures to enhance safeguards, and proliferation resistance in thorium based fuel fabrication plants  

Science Journals Connector (OSTI)

Abstract The presence of high energy gamma rays emitted by U232, which is always associated in ppm quantities with reprocessed U233, lends robustness or physical protection to the thorium fuel cycle. India is currently setting up a thorium based fuel cycle for its Advanced Heavy Water Reactor (AHWR). Identification and deployment of suitable extrinsic measures for fuel fabrication facilities would help in strengthening overall proliferation resistance. The extrinsic measures proposed in this paper include several measures which have been identified for the first time. A quantitative assessment of the contribution of these measures to overall safeguardability of the fuel fabrication plant has been carried out. Multi Attribute Utility Analysis (MAUA) has been used to evaluate the Proliferation Resistance (PR) value for two hypothetical facilities, one employing none of these measures and the other employing some or all of these measures. The analysis is based on the expert opinion of designers, operators, quality control managers and implementers of safeguards in fuel cycle facilities. Sensitivity analysis for all the proposed measures has also been carried out to study the effect of the influence of individual measures on the overall proliferation resistance of the fuel fabrication plant. The analysis ranks various safeguards measures based on the importance factor of a measure which is defined as the ratio of overall proliferation resistance with and without the measure. Important measures identified based on ranking are near real time monitoring, automation, safeguards-by-design, dynamic nuclear material accounting, and plant imaging.

Suresh Gangotra; R.B. Grover; K.L. Ramakumar

2014-01-01T23:59:59.000Z

143

A quantum cascade laser fabricated using planar native-oxide layers C. D. Farmera)  

E-Print Network (OSTI)

of quantum cascade lasers. The native oxide of the Al0.48In0.52As upper cladding layer was formed and usedA quantum cascade laser fabricated using planar native-oxide layers C. D. Farmera) Department to provide electrical and optical confinement for lasers operating at 5 m. Initial results include 1.4 W peak

144

Solid Oxide Fuel Cell and PowerSolid Oxide Fuel Cell and Power S t D l t t PNNLS t D l t t PNNLSystem Development at PNNLSystem Development at PNNL  

E-Print Network (OSTI)

Solid Oxide Fuel Cell and PowerSolid Oxide Fuel Cell and Power S t D l t t PNNLS t D l;Solid Oxide Fuel Cell CharacteristicsSolid Oxide Fuel Cell Characteristics High temperature (~700 ­ 800 of SOFCDevelopment of SOFC TTechnologyechnology Fuel Reforming and System DesignFuel Reforming and System Design

145

Survey of Worldwide Light Water Reactor Experience with Mixed Uranium-Plutonium Oxide Fuel  

SciTech Connect

The US and the Former Soviet Union (FSU) have recently declared quantities of weapons materials, including weapons-grade (WG) plutonium, excess to strategic requirements. One of the leading candidates for the disposition of excess WG plutonium is irradiation in light water reactors (LWRs) as mixed uranium-plutonium oxide (MOX) fuel. A description of the MOX fuel fabrication techniques in worldwide use is presented. A comprehensive examination of the domestic MOX experience in US reactors obtained during the 1960s, 1970s, and early 1980s is also presented. This experience is described by manufacturer and is also categorized by the reactor facility that irradiated the MOX fuel. A limited summary of the international experience with MOX fuels is also presented. A review of MOX fuel and its performance is conducted in view of the special considerations associated with the disposition of WG plutonium. Based on the available information, it appears that adoption of foreign commercial MOX technology from one of the successful MOX fuel vendors will minimize the technical risks to the overall mission. The conclusion is made that the existing MOX fuel experience base suggests that disposition of excess weapons plutonium through irradiation in LWRs is a technically attractive option.

Cowell, B.S.; Fisher, S.E.

1999-02-01T23:59:59.000Z

146

Solid-oxide fuel cell electrolyte  

DOE Patents (OSTI)

A solid-oxide electrolyte operable at between 600.degree. C. and 800.degree. C. and a method of producing the solid-oxide electrolyte are provided. The solid-oxide electrolyte comprises a combination of a compound having weak metal-oxygen interactions with a compound having stronger metal-oxygen interactions whereby the resulting combination has both strong and weak metal-oxygen interaction properties.

Bloom, Ira D. (Bolingbrook, IL); Hash, Mark C. (Joliet, IL); Krumpelt, Michael (Naperville, IL)

1993-01-01T23:59:59.000Z

147

Graphene sheets fabricated from disposable paper cups as a catalyst support material for fuel cells  

E-Print Network (OSTI)

Graphene sheets fabricated from disposable paper cups as a catalyst support material for fuel cells Hong Zhao and T. S. Zhao* Disposable paper-cups are used for the formation of graphene sheets with Fe2+ as a catalyst. The proposed synthesis strategy not only enables graphene sheets to be produced in high yield

Zhao, Tianshou

148

Serially connected solid oxide fuel cells having monolithic cores  

DOE Patents (OSTI)

A solid oxide fuel cell for electrochemically combining fuel and oxidant for generating galvanic output, wherein the cell core has an array of cell segments electrically serially connected in the flow direction, each segment consisting of electrolyte walls and interconnect that are substantially devoid of any composite inert materials for support. Instead, the core is monolithic, where each electrolyte wall consists of thin layers of cathode and anode materials sandwiching a thin layer of electrolyte material therebetween. Means direct the fuel to the anode-exposed core passageways and means direct the oxidant to the cathode-exposed core passageways; and means also direct the galvanic output to an exterior circuit. Each layer of the electrolyte composite materials is of the order of 0.002-0.01 cm thick; and each layer of the cathode and anode materials is of the order of 0.002-0.05 cm thick. Between 2 and 50 cell segments may be connected in series.

Herceg, Joseph E. (Naperville, IL)

1987-01-01T23:59:59.000Z

149

Materials System for Intermediate Temperature Solid Oxide Fuel Cell  

SciTech Connect

The objective of this work was to obtain a stable materials system for intermediate temperature solid oxide fuel cell (SOFC) capable of operating between 600-800 C with a power density greater than 0.2 W/cm{sup 2}. The solid electrolyte chosen for this system was La{sub 0.9}Sr{sub 0.1}Ga{sub 0.8}Mg{sub 0.2}O{sub 3}, (LSGM). To select the right electrode materials from a group of possible candidate materials, AC complex impedance spectroscopy studies were conducted between 600-800 C on symmetrical cells that employed the LSGM electrolyte. Based on the results of the investigation, LSGM electrolyte supported SOFCs were fabricated with La{sub 0.6}Sr{sub 0.4}Co{sub 0.8}Fe{sub 0.2}O{sub 3}-La{sub 0.9}Sr{sub 0.1}Ga{sub 0.8}Mg{sub 0.2}O{sub 3} (LSCF-LSGM) composite cathode and Nickel-Ce{sub 0.6}La{sub 0.4}O{sub 3} (Ni-LDC) composite anode having a barrier layer of Ce{sub 0.6}La{sub 0.4}O{sub 3} (LDC) between the LSGM electrolyte and the Ni-LDC anode. Electrical performance and stability of these cells were determined and the electrode polarization behavior as a function of cell current was modeled between 600-800 C. The electrical performance of the anode-supported SOFC was simulated assuming an electrode polarization behavior identical to the LSGM-electrolyte-supported SOFC. The simulated electrical performance indicated that the selected material system would provide a stable cell capable of operating between 600-800 C with a power density between 0.2 to 1 W/cm{sup 2}.

Uday B. Pal; Srikanth Gopalan

2006-01-12T23:59:59.000Z

150

Cost and Schedule of the Mixed Oxide Fuel Fabrication Facility...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

at the Savannah River Site" BACKGROUND In September 2000, the United States and Russia signed a Plutonium Management and Disposition Agreement for the disposal of surplus...

151

Functionally Graded Cathodes for Solid Oxide Fuel Cells  

SciTech Connect

This DOE SECA project focused on both experimental and theoretical understanding of oxygen reduction processes in a porous mixed-conducting cathode in a solid oxide fuel cell (SOFC). Elucidation of the detailed oxygen reduction mechanism, especially the rate-limiting step(s), is critical to the development of low-temperature SOFCs (400 C to 700 C) and to cost reduction since much less expensive materials may be used for cell components. However, cell performance at low temperatures is limited primarily by the interfacial polarization resistances, specifically by those associated with oxygen reduction at the cathode, including transport of oxygen gas through the porous cathode, the adsorption of oxygen onto the cathode surface, the reduction and dissociation of the oxygen molecule (O{sub 2}) into the oxygen ion (O{sup 2-}), and the incorporation of the oxygen ion into the electrolyte. In order to most effectively enhance the performance of the cathode at low temperatures, we must understand the mechanism and kinetics of the elementary processes at the interfaces. Under the support of this DOE SECA project, our accomplishments included: (1) Experimental determination of the rate-limiting step in the oxygen reduction mechanism at the cathode using in situ FTIR and Raman spectroscopy, including surface- and tip-enhanced Raman spectroscopy (SERS and TERS). (2) Fabrication and testing of micro-patterned cathodes to compare the relative activity of the TPB to the rest of the cathode surface. (3) Construction of a mathematical model to predict cathode performance based on different geometries and microstructures and analyze the kinetics of oxygen-reduction reactions occurring at charged mixed ionic-electronic conductors (MIECs) using two-dimensional finite volume models with ab initio calculations. (4) Fabrication of cathodes that are graded in composition and microstructure to generate large amounts of active surface area near the cathode/electrolyte interface using a novel combustion chemical vapor deposition (CCVD) technique. (5) Application of advanced quantum chemical calculations to interpret measured spectroscopic information, as well as to guide design of high efficient cathode materials.

YongMan Choi; Meilin Liu

2006-09-30T23:59:59.000Z

152

The Performance of Planar Solid Oxide Fuel Cells using Hydrogen-depleted Coal Syngas.  

E-Print Network (OSTI)

??Since solid oxide fuel cells can operate on fuel containing both hydrogen and carbon monoxide, it may prove possible to remove hydrogen from syngas streams… (more)

Burnette, David D.

2007-01-01T23:59:59.000Z

153

Numerical Simulation of Electrolyte-Supported Planar Button Solid Oxide Fuel Cell.  

E-Print Network (OSTI)

??Solid Oxide Fuel Cells are fuel cells that operate at high temperatures usually in the range of 600 °C to 1000 °C and employ solid… (more)

Aman, Amjad

2012-01-01T23:59:59.000Z

154

Molten Metal Anodes for Direct Carbon-Solid Oxide Fuel Cells.  

E-Print Network (OSTI)

??The aim of this thesis was to enable the direct utilization of solid carbonaceous fuels like coal and biomass, in solid oxide fuel cells (SOFC).… (more)

Jayakumar, Abhimanyu

2012-01-01T23:59:59.000Z

155

Microstructure-based solid oxide fuel cell seal design using statistical mechanics.  

E-Print Network (OSTI)

??Solid oxide fuel cells (SOFC) in a flat-plate configuration require a hermetic seal between the fuel and air sides of the electrodes, and this seal… (more)

Milhans, Jacqueline Linda

2010-01-01T23:59:59.000Z

156

Automated catalyst processing for cloud electrode fabrication for fuel cells  

DOE Patents (OSTI)

A process for making dry carbon/polytetrafluoroethylene floc material, particularly useful in the manufacture of fuel cell electrodes, comprises of the steps of floccing a co-suspension of carbon particles and polytetrafluoroethylene particles, filtering excess liquids from the co-suspension, molding pellet shapes from the remaining wet floc solids without using significant pressure during the molding, drying the wet floc pellet shapes within the mold at temperatures no greater than about 150.degree. F., and removing the dry pellets from the mold.

Goller, Glen J. (West Springfield, MA); Breault, Richard D. (Coventry, CT)

1980-01-01T23:59:59.000Z

157

Conductivity fuel cell collector plate and method of fabrication  

DOE Patents (OSTI)

An improved method of manufacturing a PEM fuel cell collector plate is disclosed. During molding a highly conductive polymer composite is formed having a relatively high polymer concentration along its external surfaces. After molding the polymer rich layer is removed from the land areas by machining, grinding or similar process. This layer removal results in increased overall conductivity of the molded collector plate. The polymer rich surface remains in the collector plate channels, providing increased mechanical strength and other benefits to the channels. The improved method also permits greater mold cavity thickness providing a number of advantages during the molding process.

Braun, James C. (Juno Beach, FL)

2002-01-01T23:59:59.000Z

158

Development of an External Fuel Processor for a Solid Oxide Fuel Cell  

SciTech Connect

A 250 kW External Fuel Processor was developed and tested that will supply the gases needed by a pipeline natural gas fueled, solid oxide fuel cell during all modes of operation. The fuel processor consists of three major subsystems--a desulfurizer to remove fuel sulfur to an acceptable level, a synthesis gas generator to support plant heat-up and low load fuel cell operations, and a start gas generator to supply a non-flammable, reducing gas to the fuel cell during startup and shutdown operations. The desulfurization subsystem uses a selective catalytic sulfur oxidation process that was developed for operation at elevated pressure and removes the fuel sulfur to a total sulfur content of less than 80 ppbv. The synthesis gas generation subsystem uses a waterless, catalytic partial oxidation reactor to produce a hydrogen-rich mixture from the natural gas and air. An operating window was defined that allows carbon-free operation while maintaining catalyst temperatures that will ensure long-life of the reactor. The start gas subsystem generates an oxygen-free, reducing gas from the pipeline natural gas using a low-temperature combustion technique. These physically and thermally integrated subsystems comprise the 250 kW External Fuel Processor. The 250 kW External Fuel Processor was tested at the Rolls-Royce facility in North Canton, Ohio to verify process performance and for comparison with design specifications. A step wise operation of the automatic controls through the startup, normal operation and shutdown sequences allowed the control system to be tuned and verified. A fully automated system was achieved that brings the fuel processor through its startup procedure, and then await commands from the fuel cell generator module for fuel supply and shutdown. The fuel processor performance met all design specifications. The 250 kW External Fuel Processor was shipped to an American Electric Power site where it will be tested with a Rolls-Royce solid oxide fuel cell generator module.

Daniel Birmingham; Crispin Debellis; Mark Perna; Anant Upadhyayula

2008-02-28T23:59:59.000Z

159

LG Solid Oxide Fuel Cell (SOFC) Model Development  

SciTech Connect

This report presents a summary of the work performed by LG Fuel Cell Systems Inc. during the project LG Solid Oxide Fuel Cell (SOFC) Model Development (DOE Award Number: DE-FE0000773) which commenced on October 1, 2009 and was completed on March 31, 2013. The aim of this project is for LG Fuel Cell Systems Inc. (formerly known as Rolls-Royce Fuel Cell Systems (US) Inc.) (?LGFCS?) to develop a multi-physics solid oxide fuel cell (SOFC) computer code (MPC) for performance calculations of the LGFCS fuel cell structure to support fuel cell product design and development. A summary of the initial stages of the project is provided which describes the MPC requirements that were developed and the selection of a candidate code, STAR-CCM+ (CD-adapco). This is followed by a detailed description of the subsequent work program including code enhancement and model verification and validation activities. Details of the code enhancements that were implemented to facilitate MPC SOFC simulations are provided along with a description of the models that were built using the MPC and validated against experimental data. The modeling work described in this report represents a level of calculation detail that has not been previously available within LGFCS.

Haberman, Ben; Martinez-Baca, Carlos; Rush, Greg

2013-03-31T23:59:59.000Z

160

Aerosol Jet Printing of LSCF-CGO Cathode for Solid Oxide Fuel Cells.  

E-Print Network (OSTI)

??Solid oxide fuel cell (SOFC) technology has attracted great attention due to advantages such as low emissions and high efficiency. In this work, solid oxide… (more)

Gardner, Paul

2011-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "oxide fuel fabrication" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


161

Thermal Stress Analysis of LCA-based Solid Oxide Fuel Cells.  

E-Print Network (OSTI)

??This research characterizes the thermal stress resulting from temperature gradients in hybrid solid oxide fuel cells that are processed using a novel oxide powder slurry… (more)

LeMasters, Jason Augustine

2004-01-01T23:59:59.000Z

162

Design, fabrication and testing of a liquid hydrogen fuel tank for a long duration aircraft  

Science Journals Connector (OSTI)

Liquid hydrogen has distinct advantages as an aircraft fuel. These include a specific heat of combustion 2.8 times greater than gasoline or jet fuel and zero carbon emissions. It can be utilized by fuel cells turbine engines and internal combustion engines. The high heat of combustion is particularly important in the design of long endurance aircraft with liquid hydrogen enabling cruise endurance of several days. However the mass advantage of the liquid hydrogen fuel will result in a mass advantage for the fuel system only if the liquid hydrogen tank and insulation mass is a small fraction of the hydrogen mass. The challenge is producing a tank that meets the mass requirement while insulating the cryogenic liquid hydrogen well enough to prevent excessive heat leak and boil off. In this paper we report on the design fabrication and testing of a liquid hydrogen fuel tank for a prototype high altitude long endurance (HALE) demonstration aircraft. Design options on tank geometry tank wall material and insulation systems are discussed. The final design is an aluminum sphere insulated with spray on foam insulation (SOFI). Several steps and organizations were involved in the tank fabrication and test. The tank was cold shocked helium leak checked and proof pressure tested. The overall thermal performance was verified with a boil off test using liquid hydrogen.

Gary L. Mills; Brian Buchholtz; Al Olsen

2012-01-01T23:59:59.000Z

163

Effects of mesh and interconnector design on solid oxide fuel cell performance  

Science Journals Connector (OSTI)

Abstract In this study, three different nickel based meshes are investigated as an anode side current collector and flow-field for solid oxide fuel cells (SOFCs) to reduce the fabrication cost. The same meshes are also tested on the conventional interconnectors with machined gas channels for comparison. Eight different short stacks are installed for this purpose. The characterizations of the short stacks are achieved via performance tests together with electrochemical impedance spectroscopy analyses. The experimental results reveal that the woven nickel mesh provides the required current collection and can act as an anode flow-field. It is also found that the spot welding of this mesh significantly improves the cell performance due to the enhanced contact between the mesh and the interconnector. Therefore, the spot welded nickel mesh can be directly employed on the anode interconnector as an effective anode current collector and flow-field without machining gas channels to reduce the SOFC cell/stack fabrication cost.

Murat Canavar; Yuksel Kaplan

2014-01-01T23:59:59.000Z

164

Solid oxide fuel cell with single material for electrodes and interconnect  

DOE Patents (OSTI)

A solid oxide fuel cell having a plurality of individual cells. A solid oxide fuel cell has an anode and a cathode with electrolyte disposed therebetween, and the anode, cathode and interconnect elements are comprised of substantially one material.

McPheeters, Charles C. (Naperville, IL); Nelson, Paul A. (Wheaton, IL); Dees, Dennis W. (Downers Grove, IL)

1994-01-01T23:59:59.000Z

165

Validation of a solid oxide fuel cell model  

Science Journals Connector (OSTI)

The need to study the performance of solid oxide fuel cells (SOFCs) has made mathematical modeling an essential tool for their design. Electrochemical modeling evaluates ohmic activation and concentration overpotentials that affect SOFC operation. A detailed cell model is developed for an SOFC and is validated with experimental data from the open literature.

Christina Charalampidou; Ioannis K. Kookos

2012-01-01T23:59:59.000Z

166

Integrating Multiple Solid Oxide Fuel Cell Modules* Burak Ozpineci1  

E-Print Network (OSTI)

than traditional generators even though they still have an important level of greenhouse gas (CO2 for more than a century. Today, as conventional fossil energy supplies, such as oil, coal and natural gas of Energy's Solid-State Energy Conversion Alliance (SECA) program [3] is targeting solid oxide fuel cell

Tolbert, Leon M.

167

Nanofiber Scaffold for Cathode of Solid Oxide Fuel Cell  

SciTech Connect

A high performance solid oxide fuel cell cathode using the yttria-stabilized zirconia (YSZ) nanofibers scaffold with the infiltrated La1-xSrxMnO3 (LSM) shows an enhanced catalytic activity toward oxygen reduction. Such a cathode offers a continuous path for charge transport and an increased number of triple-phase boundary sites.

Mingjia Zhi; Nicholas Mariani; Randall Gemmen; Kirk Gerdes; Nianqiang Wu

2010-10-01T23:59:59.000Z

168

Review article Components manufacturing for solid oxide fuel cells  

E-Print Network (OSTI)

-stabilized zirconia, YSZ) and the electrocatalyst (lanthanum manganite for the cathode and nickel metal for the anode are stressed. Especially for planar cell designs, the chromium contamination of the cathode and interfacial; Processing; Interconnect materials 1. Introduction Worldwide, several developers of solid oxide fuel cell

Gleixner, Stacy

169

Nonprecious Metal Catalysts for Low Temperature Solid Oxide Fuel Cells  

Science Journals Connector (OSTI)

Nonprecious Metal Catalysts for Low Temperature Solid Oxide Fuel Cells ... Initial and final state geometries are found with standard geometry optimization, then a number of intermediate states are generated by interpolation of atomic positions. ... A special "metric" and a special "preconditioning" optimized for a plane-wave basis set will be introduced. ...

Timothy P. Holme; Fritz B. Prinz

2011-05-24T23:59:59.000Z

170

New Chemical Systems for Solid Oxide Fuel Cells  

Science Journals Connector (OSTI)

New Chemical Systems for Solid Oxide Fuel Cells† ... (238) This, however, represented a significant improvement over earlier work with the use of Pt electrodes, suggesting that further improvements can be made through electrode optimization and, hence, identifying the need for more work in optimizing electrodes for use with apatite electrolytes. ... cond., the optimized compn. ...

A. Orera; P. R. Slater

2009-11-05T23:59:59.000Z

171

Solid Oxide Fuel Cell Hybrid System for Distributed Power Generation  

SciTech Connect

This report summarizes the work performed by Hybrid Power Generation Systems, LLC (HPGS) during the July 2003 to December 2003 reporting period under Cooperative Agreement DE-FC26-01NT40779 for the U. S. Department of Energy, National Energy Technology Laboratory (DOE/NETL) entitled ''Solid Oxide Fuel Cell Hybrid System for Distributed Power Generation''. The main objective of this project is to develop and demonstrate the feasibility of a highly efficient hybrid system integrating a planar Solid Oxide Fuel Cell (SOFC) and a micro-turbine. In addition, an activity included in this program focuses on the development of an integrated coal gasification fuel cell system concept based on planar SOFC technology. Also, another activity included in this program focuses on the development of SOFC scale up strategies.

Faress Rahman; Nguyen Minh

2004-01-04T23:59:59.000Z

172

Electrocatalyst for alcohol oxidation at fuel cell anodes  

DOE Patents (OSTI)

In some embodiments a ternary electrocatalyst is provided. The electrocatalyst can be used in an anode for oxidizing alcohol in a fuel cell. In some embodiments, the ternary electrocatalyst may include a noble metal particle having a surface decorated with clusters of SnO.sub.2 and Rh. The noble metal particles may include platinum, palladium, ruthenium, iridium, gold, and combinations thereof. In some embodiments, the ternary electrocatalyst includes SnO.sub.2 particles having a surface decorated with clusters of a noble metal and Rh. Some ternary electrocatalysts include noble metal particles with clusters of SnO.sub.2 and Rh at their surfaces. In some embodiments the electrocatalyst particle cores are nanoparticles. Some embodiments of the invention provide a fuel cell including an anode incorporating the ternary electrocatalyst. In some aspects a method of using ternary electrocatalysts of Pt, Rh, and SnO.sub.2 to oxidize an alcohol in a fuel cell is described.

Adzic, Radoslav (East Setauket, NY); Kowal, Andrzej (Cracow, PL)

2011-11-02T23:59:59.000Z

173

Solid Oxide Fuel Cell Balance of Plant and Stack Component Integration  

Energy.gov (U.S. Department of Energy (DOE))

Presentation by Acumentrics Corporation for Solid Oxide Fuel Cell Balance of Plant and Stack Component Integration March 16, 2010

174

Performance and degradation of metal-supported solid oxide fuel cells with impregnated electrodes  

Science Journals Connector (OSTI)

Abstract Metal-supported solid oxide fuel cells (MS-SOFCs) containing porous 430L stainless steel supports, YSZ electrolytes and porous YSZ cathode backbones are fabricated by tape casting, laminating and co-firing in a reducing atmosphere. Nano-scale Ni and La0.6Sr0.4Fe0.9Sc0.1O3?? (LSFSc) coatings are impregnated onto the internal surfaces of porous 430L and YSZ, acting as the anode and the cathode catalysts, respectively. The resulting MS-SOFCs exhibit maximum power densities of 193, 418, 636 and 907 mW cm?2 at 650, 700, 750 and 800 °C, respectively. Nevertheless, a continuous degradation in the fuel cell performance is observed at 650 °C and 0.7 V during a 200-h durability measurement. Possible degradation mechanisms were discussed in detail.

Yucun Zhou; Xianshuang Xin; Junliang Li; Xiaofeng Ye; Changrong Xia; Shaorong Wang; Zhongliang Zhan

2014-01-01T23:59:59.000Z

175

BI-LAYER p-n JUNCTION INTERCONNECTIONS FOR COAL BASED SOLID OXIDE FUEL CELLS  

SciTech Connect

In this report, a new approach for lower operating temperature solid oxide fuel cells (SOFCs) interconnections (IC) consisting of a bi-layer structure is proposed and analyzed. The bi-layer structure consists of a p-type layer exposed to cathodic gas (air/oxygen) and an n-type layer exposed to anodic gas (fuel). It is theoretically shown that the interfacial oxygen partial pressure which is an important design variable, is dependent primarily on the oxygen partial pressure gradient across the IC, the low level oxygen conductivities of the two layers and is largely independent of their electronic conductivities and the total current density through the IC material. Experimental difficulties in fabricating bi-layer structures are presently being addressed.

Srikanth Gopalan

2005-01-29T23:59:59.000Z

176

A Blueprint for GNEP Advanced Burner Reactor Startup Fuel Fabrication Facility  

SciTech Connect

The purpose of this article is to identify the requirements and issues associated with design of GNEP Advanced Burner Reactor Fuel Facility. The report was prepared in support of providing data for preparation of a NEPA Environmental Impact Statement in support the U. S. Department of Energy (DOE) Global Nuclear Energy Partnership (GNEP). One of the GNEP objectives was to reduce the inventory of long lived actinide from the light water reactor (LWR) spent fuel. The LWR spent fuel contains Plutonium (Pu) -239 and other transuranics (TRU) such as Americium-241. One of the options is to transmute or burn these actinides in fast neutron spectra as well as generate the electricity. A sodium-cooled Advanced Recycling Reactor (ARR) concept was proposed to achieve this goal. However, fuel with relatively high TRU content has not been used in the fast reactor. To demonstrate the utilization of TRU fuel in a fast reactor, an Advanced Burner Reactor (ABR) prototype of ARR was proposed, which would necessarily be started up using weapons grade (WG) Pu fuel. The WG Pu is distinguished by relatively highest proportions of Pu-239 and lesser amount of other actinides. The WG Pu was assumed to be used as the startup fuel along with TRU fuel in lead test assemblies. Because such fuel is not currently being produced in the US, a new facility (or new capability in an existing facility) was being considered for fabrication of WG Pu fuel for the ABR. It was estimated that the facility will provide the startup fuel for 10-15 years and would take 3 to 5 years to construct.

S. Khericha

2010-12-01T23:59:59.000Z

177

Advantages of Microwave Sintering in Manufacturing of Anode Support Solid Oxide Fuel Cell  

E-Print Network (OSTI)

and facile method in the manufacturing of anode support solid oxide fuel cell(1). Two anode support SOFCsPage 5-211 Advantages of Microwave Sintering in Manufacturing of Anode Support Solid Oxide Fuel oxide fuel cell (SOFC, hereafter) has been identified as an attractive technique in the recent few

Kasagi, Nobuhide

178

Evolution of microstructures inside the Ni-YSZ anode of a solid oxide fuel cell  

E-Print Network (OSTI)

Evolution of microstructures inside the Ni-YSZ anode of a solid oxide fuel cell Jeff Lillibridge Department of Mechanical & Aerospace Engineering Advisor: Mikko Haataja #12;What is a solid oxide fuel cell microstructuralcoarsening processes to electrochemical performancein solid oxide fuel cells: An integrated modeling approach

Petta, Jason

179

Oxygen diffusion in solid oxide fuel cell cathode and electrolyte materials: mechanistic insights from atomistic simulations  

E-Print Network (OSTI)

Oxygen diffusion in solid oxide fuel cell cathode and electrolyte materials: mechanistic insights to drive fast ionic transport. 1. Introduction The interest in Solid Oxide Fuel Cell (SOFC) technology. Current targets of cost and durability necessitate solid oxide fuel cells to operate in the intermediate

Yildiz, Bilge

180

Study on Degradation of Solid Oxide Fuel Cell With Pure Ni Anode Zhenjun Jiaoa  

E-Print Network (OSTI)

Study on Degradation of Solid Oxide Fuel Cell With Pure Ni Anode Zhenjun Jiaoa , Naoki Shikazonoa Solid oxide fuel cell (SOFC) has attracted more and more attentions in the last few decades hydrogen as a fuel and pure oxygen as an oxidant. Anode-reference static current method, with a current

Kasagi, Nobuhide

Note: This page contains sample records for the topic "oxide fuel fabrication" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


181

Nickel Phase Wettability and YSZ Redox Fracture Percolation in Solid Oxide Fuel Cell Anodes  

E-Print Network (OSTI)

Nickel Phase Wettability and YSZ Redox Fracture Percolation in Solid Oxide Fuel Cell Anodes Alex and Aerospace Engineering Background Solid oxide fuel cells lose mechanical stability and functionality when oxidize (redox reaction) instead of the hydrogen fuel [2]. This conversion to NiO exerts a volumetric

Petta, Jason

182

Solid-Oxide Fuel Cell Stack System Identification and Control A Systematic Recipe  

E-Print Network (OSTI)

Solid-Oxide Fuel Cell Stack System Identification and Control A Systematic Recipe Borhan M of Engineering Colorado School of Mines, Golden, CO 80401 USA Solid-Oxide Fuel Cell (MIMO) Systems Are... fuel. Sanandaji, Tyrone L. Vincent, Andrew Colclasure, and Robert J. Kee Colorado Fuel Cell Center (CFCC) Division

Sanandaji, Borhan M.

183

Steady state thermal stress analyses of two-dimensional and three-dimensional solid oxide fuel cells.  

E-Print Network (OSTI)

??Fuel cells are electrochemical devices which convert fuels directly into electrical energy without combustion. The Solid Oxide Fuel Cell (SOFC) is the most promising energy… (more)

Valluru, Srividya.

2005-01-01T23:59:59.000Z

184

Numerical analysis of an internal methane reforming solid oxide fuel cell with fuel recycling  

Science Journals Connector (OSTI)

The development of solid oxide fuel cell (SOFC) systems capable of direct internal reforming (DIR) of methane is being actively pursued. However, a major challenge with current state-of-the-art nickel-based anodes is their propensity to form deteriorous carbon deposits in DIR, unless excess steam is introduced in the fuel. Reduced fuel humidification levels are desirable from the viewpoints of cell performance, reliability and plant economics. This study explores the use of partial recycling of the anode exhaust as a mitigation strategy against carbon deposits at fuel steam-to-carbon ratios less than unity. Using a detailed computational fluid dynamics (CFD) model which couples momentum, heat, mass and charge transport with electrochemical and chemical reactions, the spatial extent of carbon deposition within a SOFC anode is analyzed by accounting for both the cracking and Boudouard reactions, for several fuel humidification and recycling conditions. At temperatures of approximately 1173 K and for inlet fuel molar H2O/CH4 ratios between 0.5 and 1, 50% (mass%) fuel recycling is found to be an effective strategy against carbon deposition. For lower recycling levels at the same fuel compositions, or lower fuel humidification levels (regardless of the recycling level), fuel recycling reduces the risk of coking, but does not eliminate it. The analyses presented suggest that recycling of the anodic fuel stream could help extend the operational range of DIR-SOFCs to lower fuel humidification levels than typically considered, with reduced risks of carbon deposits, while reducing system cost and complexity in terms of steam production. For dry or weakly humidified fuels, additional mitigation strategies would be required.

Valérie Eveloy

2012-01-01T23:59:59.000Z

185

Santa Clara County Planar Solid Oxide Fuel Cell Demonstration Project  

SciTech Connect

The Santa Clara County Planar Solid Oxide Fuel Cell (PSOFC) project demonstrated the technical viability of pre-commercial PSOFC technology at the County 911 Communications headquarters, as well as the input fuel flexibility of the PSOFC. PSOFC operation was demonstrated on natural gas and denatured ethanol. The Santa Clara County Planar Solid Oxide Fuel Cell (PSOFC) project goals were to acquire, site, and demonstrate the technical viability of a pre-commercial PSOFC technology at the County 911 Communications headquarters. Additional goals included educating local permit approval authorities, and other governmental entities about PSOFC technology, existing fuel cell standards and specific code requirements. The project demonstrated the Bloom Energy (BE) PSOFC technology in grid parallel mode, delivering a minimum 15 kW over 8760 operational hours. The PSOFC system demonstrated greater than 81% electricity availability and 41% electrical efficiency (LHV net AC), providing reliable, stable power to a critical, sensitive 911 communications system that serves geographical boundaries of the entire Santa Clara County. The project also demonstrated input fuel flexibility. BE developed and demonstrated the capability to run its prototype PSOFC system on ethanol. BE designed the hardware necessary to deliver ethanol into its existing PSOFC system. Operational parameters were determined for running the system on ethanol, natural gas (NG), and a combination of both. Required modeling was performed to determine viable operational regimes and regimes where coking could occur.

Fred Mitlitsky; Sara Mulhauser; David Chien; Deepak Shukla; David Weingaertner

2009-11-14T23:59:59.000Z

186

Degradation of solid oxide fuel cell metallic interconnects in fuels containing sulfur  

SciTech Connect

Hydrogen is the main fuel for all types of fuel cells except direct methanol fuel cells. Hydrogen can be generated from all manner of fossil fuels, including coal, natural gas, diesel, gasoline, other hydrocarbons, and oxygenates (e.g., methanol, ethanol, butanol, etc.). Impurities in the fuel can cause significant performance problems and sulfur, in particular, can decrease the cell performance of fuel cells, including solid oxide fuel cells (SOFC). In the SOFC, the high (800-1000°C) operating temperature yields advantages (e.g., internal fuel reforming) and disadvantages (e.g., material selection and degradation problems). Significant progress in reducing the operating temperature of the SOFC from ~1000 şC to ~750 şC may allow less expensive metallic materials to be used for interconnects and as balance of plant (BOP) materials. This paper provides insight on the material performance of nickel, ferritic steels, and nickel-based alloys in fuels containing sulfur, primarily in the form of H2S, and seeks to quantify the extent of possible degradation due to sulfur in the gas stream.

Ziomek-Moroz, M.; Hawk, Jeffrey A.

2005-01-01T23:59:59.000Z

187

Kinetic Modeling of Toluene Oxidation for Surrogate Fuel Applications  

SciTech Connect

New environmental issues, like the effect of combustion-generated greenhouse gases, provide motivation to better characterize oxidation of hydrocarbons. Transportation, in particular, significantly contributes to energy consumption and CO{sub 2} emissions. Kinetic studies about the combustion of fuels under conditions typical of internal combustion engines provides important support to improve mechanism formulation and to eventually provide better computational tools that can be used to increase the engine performance. It is foreseeable that at least in the next 30 years the main transportation fuels will be either gasoline or diesel. Unfortunately, these fuels are very complex mixtures of many components. Moreover, their specifications and performance requirements significantly change the composition of these fuels: gasoline and diesel mixtures are different if coming from different refineries or they are different from winter to summer. At the same time a fuel with a well defined and reproducible composition is needed for both experimental and modeling work. In response to these issues, surrogate fuels are proposed. Surrogate fuels are defined as mixtures of a small number of hydrocarbons whose relative concentrations is adjusted in order to approximate the chemical and physical properties of a real fuel. Surrogate fuels are then very useful both for the design of reproducible experimental tests and also for the development of reliable kinetic models. The primary reference fuels (PRF) are a typical and old example of surrogate fuel: n-heptane and iso-octane mixtures are used to reproduce antiknock propensity of complex mixtures contained in a gasoline. PRFs are not able to surrogate gasoline in operating conditions different from standard ones and new surrogates have been recently proposed. Toluene is included in all of them as a species able to represent the behavior of aromatic compounds. On the other side, the toluene oxidation chemistry is not so well established and uncertainties still remain in the mechanism. This is especially true in the low temperature regime (< 850K). In these conditions, the toluene reactivity is too low to be conveniently investigated. Nonetheless, gasoline surrogates work in the engine at low temperatures, because of the presence of very reactive alkanes. The effect of these component interactions have to be taken into account. This work's aim is to present the model activity carried out by two different research groups, comparing the main pathways and results, matching data carried out in different devices both for pure toluene and mixtures. This is the starting point for a further activity to improve the two kinetic schemes.

Frassoldati, A; Mehl, M; Fietzek, R; Faravelli, T; Pitz, W J; Ranzi, E

2009-04-21T23:59:59.000Z

188

Accident safety analysis for 300 Area N Reactor Fuel Fabrication and Storage Facility  

SciTech Connect

The purpose of the accident safety analysis is to identify and analyze a range of credible events, their cause and consequences, and to provide technical justification for the conclusion that uranium billets, fuel assemblies, uranium scrap, and chips and fines drums can be safely stored in the 300 Area N Reactor Fuel Fabrication and Storage Facility, the contaminated equipment, High-Efficiency Air Particulate filters, ductwork, stacks, sewers and sumps can be cleaned (decontaminated) and/or removed, the new concretion process in the 304 Building will be able to operate, without undue risk to the public, employees, or the environment, and limited fuel handling and packaging associated with removal of stored uranium is acceptable.

Johnson, D.J.; Brehm, J.R.

1994-01-01T23:59:59.000Z

189

Tubular solid oxide fuel cell prospect  

SciTech Connect

Driven by technological achievement and rational projection of commercial product cost, expectations for tubular SOFC commercialization are improving. Tubular SOFCs have surpassed 7 yrs operation and have recently demonstrated remarkable toughness in thermal cycling. Customer-owned systems with 25 kW stacks utilizing air electrode supported (AES) cells continue to operate directly on natural gas without degradation after multiple thermal cycles and over 4000 hrs operation. AES cell operation at elevated pressure corroborates theoretical estimates of performance gain without evidence of deleterious effect. Commercial class AES cell of 22 mm dia and 1500 mm length, is now in production for application to 100 kW, 50% efficient (ac/LHV), atmospheric pressure systems. This same cell applied to pressurized systems in combination with conventional turbo machinery (gas turbines) can yield an efficiency approaching 70% for power plants as small as 5 MW. Total installed system cost for commercial 5 MW SOFC/CT units for distributed power generation and on-site cogeneration should approach $1000/kW. A major challenge is formation of funded projects to demonstrate at the turn of the century prototype MW class SOFC/CT combined cycle power plants and to complete the development of commercial fuel cell manufacturing processes.

Veyo, S.E.

1996-05-01T23:59:59.000Z

190

Topological analysis of hydrogen oxidation reaction kinetics at Ni/YSZ anode of the solid oxide fuel cell.  

E-Print Network (OSTI)

??The understanding of the mechanisms and kinetics of reactions that occur on the electrodes hold the key to further advances in solid oxide fuel cell… (more)

Dar, Yasir Rasool

2011-01-01T23:59:59.000Z

191

DEVELOPMENT OF LOW-COST MANUFACTURING PROCESSES FOR PLANAR, MULTILAYER SOLID OXIDE FUEL CELL ELEMENTS  

SciTech Connect

This report summarizes the results of a four-year project, entitled, ''Low-Cost Manufacturing Of Multilayer Ceramic Fuel Cells'', jointly funded by the U.S. Department of Energy, the State of Ohio, and by project participants. The project was led by NexTech Materials, Ltd., with subcontracting support provided by University of Missouri-Rolla, Michael A. Cobb & Co., Advanced Materials Technologies, Inc., Edison Materials Technology Center, Gas Technology Institute, Northwestern University, and The Ohio State University. Oak Ridge National Laboratory, though not formally a subcontractor on the program, supported the effort with separate DOE funding. The objective of the program was to develop advanced manufacturing technologies for making solid oxide fuel cell components that are more economical and reliable for a variety of applications. The program was carried out in three phases. In the Phase I effort, several manufacturing approaches were considered and subjected to detailed assessments of manufacturability and development risk. Estimated manufacturing costs for 5-kW stacks were in the range of $139/kW to $179/kW. The risk assessment identified a number of technical issues that would need to be considered during development. Phase II development work focused on development of planar solid oxide fuel cell elements, using a number of ceramic manufacturing methods, including tape casting, colloidal-spray deposition, screen printing, spin-coating, and sintering. Several processes were successfully established for fabrication of anode-supported, thin-film electrolyte cells, with performance levels at or near the state-of-the-art. The work in Phase III involved scale-up of cell manufacturing methods, development of non-destructive evaluation methods, and comprehensive electrical and electrochemical testing of solid oxide fuel cell materials and components.

Scott Swartz; Matthew Seabaugh; William Dawson; Harlan Anderson; Tim Armstrong; Michael Cobb; Kirby Meacham; James Stephan; Russell Bennett; Bob Remick; Chuck Sishtla; Scott Barnett; John Lannutti

2004-06-12T23:59:59.000Z

192

SOLID OXIDE FUEL CELL HYBRID SYSTEM FOR DISTRIBUTED POWER GENERATION  

SciTech Connect

This report summarizes the work performed by Honeywell during the July 2001 to September 2001 reporting period under Cooperative Agreement DE-FC26-01NT40779 for the U. S. Department of Energy, National Energy Technology Laboratory (DOE/NETL) entitled ''Solid Oxide Fuel Cell Hybrid System for Distributed Power Generation''. The main objective of this project is to develop and demonstrate the feasibility of a highly efficient hybrid system integrating a planar Solid Oxide Fuel Cell (SOFC) and a turbogenerator. An internal program kickoff was held at Honeywell in Torrance, CA. The program structure was outlined and the overall technical approach for the program was presented to the team members. Detail program schedules were developed and detailed objectives were defined. Initial work has begun on the system design and pressurized SOFC operation.

Unknown

2002-03-01T23:59:59.000Z

193

Solid Oxide Fuel Cell Hybrid System for Distributed Power Generation  

SciTech Connect

This report summarizes the work performed by Honeywell during the January 2002 to March 2002 reporting period under Cooperative Agreement DE-FC26-01NT40779 for the U. S. Department of Energy, National Energy Technology Laboratory (DOE/NETL) entitled ''Solid Oxide Fuel Cell Hybrid System for Distributed Power Generation''. The main objective of this project is to develop and demonstrate the feasibility of a highly efficient hybrid system integrating a planar Solid Oxide Fuel Cell (SOFC) and a turbogenerator. For this reporting period the following activities have been carried out: {lg_bullet} Conceptual system design trade studies were performed {lg_bullet} System-level performance model was created {lg_bullet} Dynamic control models are being developed {lg_bullet} Mechanical properties of candidate heat exchanger materials were investigated {lg_bullet} SOFC performance mapping as a function of flow rate and pressure was completed

Nguyen Minh

2002-03-31T23:59:59.000Z

194

Thermo Physical Properties of Materials for Solid Oxide Fuel Cells  

Science Journals Connector (OSTI)

Solid oxide fuel cells (SOFCs) are energy conversion devices that convert chemical energy to electrical energy with high efficiency and have the added advantage of least production of pollutants during their operation. SOFCs comprise of a number of components such as the anode the electrolyte the cathode and the interconnect. Each of these components is made of a different material with different thermophysical and electrical properties. Thermal expansion coefficient is one of the most important properties of these compounds. Various components should have matching thermal expansion behaviour to avoid cracking during thermal cycling and for long term operation of SOFCs. In this article the thermophysical properties of materials for solid oxide fuel cells will be discussed with special emphasize on their thermal expansion behaviour.

S. R. Bharadwaj

2010-01-01T23:59:59.000Z

195

Modeling Tools for Solid Oxide Fuel Cell Analysis  

NLE Websites -- All DOE Office Websites (Extended Search)

Tools for Solid Oxide Fuel Tools for Solid Oxide Fuel Cell Design and Analysis Moe A Khaleel BJ Koeppel, W Liu, K Lai, KP Recknagle, EM Ryan, EV Stephens, X Sun Pacific Northwest National Laboratory Richland, WA 99352 11 th Annual SECA Workshop Pittsburgh, PA July 27-29, 2009 1 PNNL SOFC Modeling Tools SOFC-MP Stack level model for fast analysis of co/counter-flow SOFC stack performance Detailed electrochemistry model Cell level model for the investigation of secondary reactions (degradation/contamination) mechanisms within the tri-layer Component-based design and performance modeling Contact material Interconnect Glass seal 2 SOFC-MP Stack Simulation Code Recent Accomplishments Major memory improvements of 3D model to accommodate 50-cell stacks on LINUX platform. Previously, developed a 2D (or stacked

196

Electrode Performance in Reversible Solid Oxide Fuel Cells  

SciTech Connect

The performance of several negative (fuel) and positive (air) electrode compositions for use in reversible solid oxide fuel cells (SOFC) that are capable of operating both as a fuel cell and as an electrolyzer was investigated in half-cell and full-cell tests. Negative electrode compositions studied were a nickel/zirconia cermet (Ni/YSZ) and lanthanum-substituted strontium titanate/ceria composite, whereas positive electrode compositions examined included mixed ion and electron-conducting lanthanum strontium ferrite (LSF), lanthanum strontium copper ferrite (LSCuF), lanthanum strontium cobalt ferrite (LSCoF), and lanthanum strontium manganite (LSM). While titanate/ceria and Ni/YSZ electrodes performed similarly in the fuel cell mode in half-cell tests, losses associated with electrolysis were lower for the titanate/ceria electrode. Positive electrodes all gave higher losses in the electrolysis mode when compared to the fuel cell mode. This behavior was most apparent for mixed-conducting LSF, LSCuF, and LSCoF electrodes, and discernible but smaller for LSM; observations are consistent with expected trends in the interfacial oxygen vacancy concentration under anodic and cathodic polarization. Full-cell tests conducted for cells with a thin electrolyte (7 um YSZ) similarly showed higher polarization losses in the electrolysis than fuel cell direction.

Marina, Olga A.; Pederson, Larry R.; Williams, Mark C.; Coffey, Greg W.; Meinhardt, Kerry D.; Nguyen, Carolyn D.; Thomsen, Ed C.

2007-03-22T23:59:59.000Z

197

Structural and electrochemical characterization of two proton conducting oxide thin films for a microfabricated solid oxide fuel cell  

E-Print Network (OSTI)

The use of proton conducting oxide materials as an electrolyte offers the potential to reduce the operating temperature of a solid oxide fuel cell (SOFC), leading to improved thermal management and material compatibility. ...

Capozzoli, Peter M

2006-01-01T23:59:59.000Z

198

Electrical contact structures for solid oxide electrolyte fuel cell  

DOE Patents (OSTI)

An improved electrical output connection means is provided for a high temperature solid oxide electrolyte type fuel cell generator. The electrical connection of the fuel cell electrodes to the electrical output bus, which is brought through the generator housing to be connected to an electrical load line maintains a highly uniform temperature distribution. The electrical connection means includes an electrode bus which is spaced parallel to the output bus with a plurality of symmetrically spaced transversely extending conductors extending between the electrode bus and the output bus, with thermal insulation means provided about the transverse conductors between the spaced apart buses. Single or plural stages of the insulated transversely extending conductors can be provided within the high temperatures regions of the fuel cell generator to provide highly homogeneous temperature distribution over the contacting surfaces.

Isenberg, Arnold O. (Forest Hills, PA)

1984-01-01T23:59:59.000Z

199

Serially connected solid oxide fuel cells having monolithic cores  

DOE Patents (OSTI)

Disclosed is a solid oxide fuel cell for electrochemically combining fuel and oxidant for generating galvanic output. The cell core has an array of cell segments electrically serially connected in the flow direction, each segment consisting of electrolyte walls and interconnect that are substantially devoid of any composite inert materials for support. Instead, the core is monolithic, where each electrolyte wall consists of thin layers of cathode and anode materials sandwiching a thin layer of electrolyte material therebetween. Means direct the fuel to the anode-exposed core passageways and means direct the oxidant to the cathode-exposed core passageways; and means also direct the galvanic output to an exterior circuit. Each layer of the electrolyte composite materials is of the order of 0.002 to 0.01 cm thick; and each layer of the cathode and anode materials is of the order of 0.002 to 0.05 cm thick. Between 2 and 50 cell segments may be connected in series.

Herceg, J.E.

1985-05-20T23:59:59.000Z

200

Method and apparatus for assembling solid oxide fuel cells  

DOE Patents (OSTI)

This invention relates generally to solid oxide fuel power generators and is particularly directed to improvements in the assembly and coupling of solid oxide fuel cell modules. A plurality of jet air tubes are supported and maintained in a spaced matrix array by a positioning/insertion assembly for insertion in respective tubes of a solid oxide fuel cell (SOFC) in the assembly of an SOFC module. The positioning/insertion assembly includes a plurality of generally planar, elongated, linear vanes which are pivotally mounted at each end thereof to a support frame. A rectangular compression assembly of adjustable size is adapted to receive and squeeze a matrix of SOFC tubes so as to compress the inter-tube nickel felt conductive pads which provide series/parallel electrical connection between adjacent SOFCs, with a series of increasingly larger retainer frames used to maintain larger matrices of SOFC tubes in position. Expansion of the SOFC module housing at the high operating temperatures of the SOFC is accommodated by conductive, flexible, resilient expansion, connector bars which provide support and electrical coupling at the top and bottom of the SOFC module housing. 17 figs.

Szreders, B.E.; Campanella, N.

1988-05-11T23:59:59.000Z

Note: This page contains sample records for the topic "oxide fuel fabrication" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


201

A Reversible Planar Solid Oxide Fuel-Fed Electrolysis Cell and Solid Oxide Fuel Cell for Hydrogen and Electricity Production Operating on Natural Gas/Biomass Fuels  

SciTech Connect

A solid oxide fuel-assisted electrolysis technique was developed to co-generate hydrogen and electricity directly from a fuel at a reduced cost of electricity. Solid oxide fuel-assisted electrolysis cells (SOFECs), which were comprised of 8YSZ electrolytes sandwiched between thick anode supports and thin cathodes, were constructed and experimentally evaluated at various operation conditions on lab-level button cells with 2 cm2 per-cell active areas as well as on bench-scale stacks with 30 cm2 and 100 cm2 per-cell active areas. To reduce the concentration overpotentials, pore former systems were developed and engineered to optimize the microstructure and morphology of the Ni+8YSZ-based anodes. Chemically stable cathode materials, which possess good electronic and ionic conductivity and exhibit good electrocatalytic properties in both oxidizing and reducing gas atmospheres, were developed and materials properties were investigated. In order to increase the specific hydrogen production rate and thereby reduce the system volume and capital cost for commercial applications, a hybrid system that integrates the technologies of the SOFEC and the solid-oxide fuel cell (SOFC), was developed and successfully demonstrated at a 1kW scale, co-generating hydrogen and electricity directly from chemical fuels.

Tao, Greg, G.

2007-03-31T23:59:59.000Z

202

NOVEL ELECTRODE MATERIALS FOR LOW-TEMPERATURE SOLID-OXIDE FUEL CELLS  

SciTech Connect

Fuel cell performance depends strongly on the anode microstructure, which is determined by the anode compositions and fabrication conditions. Four types of anodes with two kinds of NiO and GDC powders were investigated. By carefully adjusting the anode microstructure, the GDC electrolyte/anode interfacial polarization resistances reduced dramatically. The interfacial resistance at 600 C decreased from 1.61 {Omega} cm{sup 2} for the anodes prepared using commercially available powders to 0.06 {Omega} cm{sup 2} for those prepared using powders derived from a glycine-nitrate process. The critical issues facing the development of economically competitive SOFC systems include lowering the operation temperature and creating novel anode materials and microstructures capable of efficiently utilizing hydrocarbon fuels. Anode-supported SOFCs with an electrolyte of 20 {micro}m- thick Gd-doped ceria (GDC) were fabricated by co-pressing, and both Ni- and Cu-based anodes were prepared by a solution impregnation process. At 600 C, SOFCs fueled with humidified H{sub 2}, methane, and propane, reached peak power densities of 602, 519, and 433 mW/cm{sup 2}, respectively. Both microstructure and composition of the anodes, as fabricated using a solution impregnation technique, greatly influence fuel cell performance. Although steam reforming or partial oxidation is effective in avoiding carbon deposition of hydrocarbon fuels, it increases the operating cost and reduces the energy efficiency. A catalyst (1 %wt Pt dispersed on porous Gd-doped ceria) for pre-reforming of propane was developed with relatively low steam to carbon (S/C) ratio ({approx}0.5), coupled with direct utilization of the reformate in low-temperature SOFCs. Propane was converted to smaller molecules during pre-reforming, including H{sub 2}, CH{sub 4}, CO, and CO{sub 2}. A peak power density of 247 mW/cm{sup 2} was observed when pre-reformed propane was directly fed to an SOFC operated at 600 C. No carbon deposition was observed in the fuel cell for a continuous operation of 10 hours at 600 C.

Shaowu Zha; Luis Aguilar; Meilin Liu

2003-12-01T23:59:59.000Z

203

New Catalysts for Direct Methanol Oxidation Fuel Cells  

SciTech Connect

A new class of efficient electrocatalytic materials based on platinum - metal oxide systems has been synthetized and characterized by several techniques. Best activity was found with NiWO{sub 4}-, CoWO{sub 4}-, and RuO{sub 2}- srˇpported platinum catalysts. A very similar activity at room temperature was observed with the electrodes prepared with the catalyst obtained from International Fuel Cells Inc. for the same Pt loading. Surprisingly, the two tungstates per se show a small activity for methanol oxidation without any Pt loading. Synthesis of NiWO{sub 4} and CoWO{sub 4} were carried out by solid-state reactions. FTIR spectroscopy shows that the tungstates contain a certain amount of physically adsorbed water even after heating samples at 200{degrees}C. A direct relationship between the activity for methanol oxidation and the amount of adsorbed water on those oxides has been found. The Ru(0001) single crystal shows a very small activity for CO adsorption and oxidation, in contrast to the behavior of polycrystalline Ru. In situ extended x-ray absorption fine structure spectroscopy (EXAFS) and x-ray absorption near edge spectroscopy (XANES) showed that the OH adsorption on Ru in the Pt-Ru alloy appears to be the limiting step in methanol oxidation. This does not occur for Pt-RuO{SUB 2} electrocatalyst, which explains its advantages over the Pt-Ru alloys. The IFCC electrocatalyst has the properties of the Pt-Ru alloy.

Adzic, Radoslav

1998-08-01T23:59:59.000Z

204

Fabrication and Testing of Full-Length Single-Cell Externally Fueled Converters for Thermionic Reactors  

SciTech Connect

The preceding paper described designs and analyses of thermionic reactors employing full-core-length single-cell converters with their heated emitters located on the outside of their internally cooled collectors, and it presented results of detailed parametric analyses which illustrate the benefits of this unconventional design. The present paper describes the fabrication and testing of full-length prototypical converters, both unfueled and fueled, and presents parametric results of electrically heated tests. The unfueled converter tests demonstrated the practicality of operating such long converters without shorting across a 0.3-mm interelectrode gap. They produced a measured peak output of 751 watts(e) from a single diode and a peak efficiency of 15.4%. The fueled converter tests measured the parametric performance of prototypic UO(subscript 2)-fueled converters designed for subsequent in-pile testing. They employed revolver-shaped tungsten elements with a central emitter hole surrounded by six fuel chambers. The full-length converters were heated by a water-cooled RF-induction coil inside an ion-pumped vacuum chamber. This required development of high-vacuum coaxial RF feedthroughs. In-pile test rules required multiple containment of the UO (subscript 2)-fuel, which complicated the fabrication of the test article and required successful development of techniques for welding tungsten and other refractory components. The test measured a peak power output of 530 watts(e) or 7.1 watts/cm (superscript 2) at an efficiency of 11.5%. There are three copies in the file. Cross-Reference a copy FSC-ESD-217-94-529 in the ESD files with a CID #8574.

Schock, Alfred

1994-06-01T23:59:59.000Z

205

Solid oxide fuel cell having a glass composite seal  

DOE Patents (OSTI)

A solid oxide fuel cell stack having a plurality of cassettes and a glass composite seal disposed between the sealing surfaces of adjacent cassettes, thereby joining the cassettes and providing a hermetic seal therebetween. The glass composite seal includes an alkaline earth aluminosilicate (AEAS) glass disposed about a viscous glass such that the AEAS glass retains the viscous glass in a predetermined position between the first and second sealing surfaces. The AEAS glass provides geometric stability to the glass composite seal to maintain the proper distance between the adjacent cassettes while the viscous glass provides for a compliant and self-healing seal. The glass composite seal may include fibers, powders, and/or beads of zirconium oxide, aluminum oxide, yttria-stabilized zirconia (YSZ), or mixtures thereof, to enhance the desirable properties of the glass composite seal.

De Rose, Anthony J.; Mukerjee, Subhasish; Haltiner, Jr., Karl Jacob

2013-04-16T23:59:59.000Z

206

MATERIAL AND PROCESS DEVELOPMENT LEADING TO ECONOMICAL HIGH-PERFORMANCE THIN-FILM SOLID OXIDE FUEL CELLS  

SciTech Connect

This document summarizes the technical progress from April to September 2003 for the program, Material and Process Development Leading to Economical High-Performance Thin-Film Solid Oxide Fuel Cells, contract number DE-AC26-00NT40711. Characteristics of doped lanthanum gallate (LSGMF) powder suitable for thin electrolyte fabrication have been defined. Bilayers with thin LSGMF electrolyte supported on an anode were fabricated and the fabrication process was improved. Preliminary performance was characterized. High performance cathode material Sr{sub 0.5}Sm{sub 0.5}CoO{sub 3} has been down-selected and is being optimized by modifying materials characteristics and processing parameters. The selected cathode exhibited excellent performance with cathode polarization of {approx}0.23 ohm-cm{sup 2} at 600 C.

Jie Guan; Nguyen Minh

2003-10-01T23:59:59.000Z

207

Design consideration of micro thin film solid-oxide fuel cells  

Science Journals Connector (OSTI)

Miniaturized planar solid-oxide fuel cells (SOFCs) and stacks can be fabricated by thin film deposition and micromachining. Serious thermal stresses, originating in fabrication and during operation, cause thermal–mechanical instability of the constituent thin films. In this paper, the effect of thin film geometry on thermal stress and mechanical stability is evaluated to optimize the structure of a thin film. A novel design of thin circular electrolyte films for SOFCs is presented by using corrugated structures, with which small thermal stresses and a broad design range of structure parameters can be obtained. Thermal transfer analysis shows that heat loss by solid conduction is serious in thin films with a small radius. But thermal convection and radiation dominate heat loss in large thin films with a radius of several millimetres. Scale-dependent thermal characteristics show the importance of film size and packaging in optimization of thermal isolation for micro SOFCs. A novel flip-flop stack configuration for micro SOFCs is presented. This configuration allows multiple cells to share one reaction chamber, helps to obtain uniform flow fields, and simplifies the flow field network for micro fuel cell stacks.

Yanghua Tang; Kevin Stanley; Jonathan Wu; Dave Ghosh; Jiujun Zhang

2005-01-01T23:59:59.000Z

208

Extended Durability Testing of an External Fuel Processor for a Solid Oxide Fuel Cell (SOFC)  

SciTech Connect

Durability testing was performed on an external fuel processor (EFP) for a solid oxide fuel cell (SOFC) power plant. The EFP enables the SOFC to reach high system efficiency (electrical efficiency up to 60%) using pipeline natural gas and eliminates the need for large quantities of bottled gases. LG Fuel Cell Systems Inc. (formerly known as Rolls-Royce Fuel Cell Systems (US) Inc.) (LGFCS) is developing natural gas-fired SOFC power plants for stationary power applications. These power plants will greatly benefit the public by reducing the cost of electricity while reducing the amount of gaseous emissions of carbon dioxide, sulfur oxides, and nitrogen oxides compared to conventional power plants. The EFP uses pipeline natural gas and air to provide all the gas streams required by the SOFC power plant; specifically those needed for start-up, normal operation, and shutdown. It includes a natural gas desulfurizer, a synthesis-gas generator and a start-gas generator. The research in this project demonstrated that the EFP could meet its performance and durability targets. The data generated helped assess the impact of long-term operation on system performance and system hardware. The research also showed the negative impact of ambient weather (both hot and cold conditions) on system operation and performance.

Mark Perna; Anant Upadhyayula; Mark Scotto

2012-11-05T23:59:59.000Z

209

Control of Natural Gas Catalytic Partial Oxidation for Hydrogen Generation in Fuel Cell Applications1  

E-Print Network (OSTI)

Control of Natural Gas Catalytic Partial Oxidation for Hydrogen Generation in Fuel Cell Ghosh3 , Huei Peng2 Abstract A fuel processor that reforms natural gas to hydrogen-rich mixture to feed of the hydrogen in the fuel processor is based on catalytic partial oxidation of the methane in the natural gas

Peng, Huei

210

Advanced Materials for Reversible Solid Oxide Fuel Cell (RSOFC), Dual Mode Operation with Low  

E-Print Network (OSTI)

Advanced Materials for Reversible Solid Oxide Fuel Cell (RSOFC), Dual Mode Operation with Low, Director Product Development & Federal Programs #12;Project Background f Reversible Solid Oxide Fuel Cells:Water The VPS Storage f Wind Fuel Cell / f Solar Electrolyzer Continuous SOFC Intermittent Power Power

211

Solid Oxide Fuel Cell Auxiliary Power Units for Long-Haul Trucks  

E-Print Network (OSTI)

Solid Oxide Fuel Cell Auxiliary Power Units for Long-Haul Trucks Modeling and Control Mohammad and maintenance of the truck engine. While still in the research phase, Solid Oxide Fuel Cell (SOFC) based APUs are used to provide this power, rather than idling the engine, because they use less fuel and reduce wear

212

Microstructural Degradation of Ni-YSZ Anodes for Solid Oxide Fuel  

E-Print Network (OSTI)

Microstructural Degradation of Ni- YSZ Anodes for Solid Oxide Fuel Cells Karl Thydén Risø-PhD-32(EN 2008 #12;Author: Karl Thydén Title: Microstructural Degradation of Ni-YSZ Anodes for Solid Oxide Fuel Cells Department: Fuel Cells and Solid State Chemistry Department Risø-PhD-32(EN) March 2008 This thesis

213

Method for producing electricity from a fuel cell having solid-oxide ionic electrolyte  

DOE Patents (OSTI)

Stabilized quadrivalent cation oxide electrolytes are employed in fuel cells at elevated temperatures with a carbon and/or hydrogen containing fuel anode and an oxygen cathode. The fuel cell is operated at elevated temperatures with conductive metallic coatings as electrodes and desirably having the electrolyte surface blackened. Of particular interest as the quadrivalent oxide is zirconia.

Mason, David M. (Los Altos, CA)

1984-01-01T23:59:59.000Z

214

Anode supported single chamber solid oxide fuel cells operating in exhaust gases of thermal engine  

E-Print Network (OSTI)

Anode supported single chamber solid oxide fuel cells operating in exhaust gases of thermal engine fuel cells are usually described as devices able to convert chemical energy into electrical energy. Conventional solid oxide fuel cells are separated into two compartments containing each electrode split

Boyer, Edmond

215

Oxidation of automotive primary reference fuels at elevated pressures  

SciTech Connect

Automotive engine knock limits the maximum operating compression ratio and ultimate thermodynamic efficiency of spark-ignition (SI) engines. In compression-ignition (CI) or diesel cycle engines, the premixed burn phase, which occurs shortly after injection, determines the time it takes for autoignition to occur. In order to improve engine efficiency and to recommend more efficient, cleaner-burning alternative fuels, they must understand the chemical kinetic processes that lead to autoignition in both SI and CI engines. These engines burn large molecular-weight blended fuels, a class to which the primary reference fuels (PRF) n-heptane and iso-octane belong. In this study, experiments were performed under engine like conditions in a high-pressure flow reactor using both the pure PRF fuels and their mixtures in the temperature range 550-880 K and 12.5 atm pressure. These experiments not only provide information on the reactivity of each fuel but also identify the major intermediate products formed during the oxidation process. A detailed chemical kinetic mechanism is used to simulate these experiments, and comparisons of experimentally measured and model predicted profiles for O{sub 2}, CO, CO{sub 2}, H{sub 2}O and temperature rise are presented. Intermediates identified in the flow reactor are compared with those present in the computations, and the kinetic pathways leading to their formation are discussed. In addition, autoignition delay times measured in a shock tube over the temperature range 690-1220 K and at 40 atm pressure were simulated. Good agreement between experiment and simulation was obtained for both the pure fuels and their mixtures. Finally, quantitative values of major intermediates measured in the exhaust gas of a cooperative fuels research engine operating under motored engine conditions are presented together with those predicted by the detailed model.

Callahan, C V; Curran, H J; Dryer, F L; Pitz, W J; Westbrook, C K

1999-03-01T23:59:59.000Z

216

Key Differences in the Fabrication, Irradiation, and Safety Testing of U.S. and German TRISO-coated Particle Fuel and Their Implications on Fuel Performance  

SciTech Connect

High temperature gas reactor technology is achieving a renaissance around the world. This technology relies on high quality production and performance of coated particle fuel. Historically, the irradiation performance of TRISO-coated gas reactor particle fuel in Germany has been superior to that in the United States. German fuel generally displayed in-pile gas release values that were three orders of magnitude lower than U.S. fuel. Thus, we have critically examined the TRISO-coated fuel fabrication processes in the U.S. and Germany and the associated irradiation database with a goal of understanding why the German fuel behaves acceptably, why the U.S. fuel has not faired as well, and what process/ production parameters impart the reliable performance to this fuel form. The postirradiation examination results are also reviewed to identify failure mechanisms that may be the cause of the poorer U.S. irradiation performance. This comparison will help determine the roles that particle fuel process/product attributes and irradiation conditions (burnup, fast neutron fluence, temperature, and degree of acceleration) have on the behavior of the fuel during irradiation and provide a more quantitative linkage between acceptable processing parameters, as-fabricated fuel properties and subsequent in-reactor performance.

Petti, David Andrew; Maki, John Thomas; Buongiorno, Jacopo; Hobbins, Richard Redfield

2002-06-01T23:59:59.000Z

217

Mixed Fuel Strategy for Carbon Deposition Mitigation in Solid Oxide Fuel Cells at Intermediate Temperatures  

Science Journals Connector (OSTI)

Mixed Fuel Strategy for Carbon Deposition Mitigation in Solid Oxide Fuel Cells at Intermediate Temperatures ... (1-4) Although the concept of SOFCs was first reported more than one century ago,(5) major technological advances in cell materials, reactor configuration, operation mode, and balance of plant system integration and optimization were realized in the last 20–30 years only. ... The hybrid start-up process is optimized with respect to a specific setup as an example, but is of general nature and utility to similar systems. ...

Chao Su; Yubo Chen; Wei Wang; Ran Ran; Zongping Shao; Joăo C. Diniz da Costa; Shaomin Liu

2014-05-23T23:59:59.000Z

218

Proton Conductor based Solid Oxide Fuel Cells Ceramatec, Inc., Salt Lake City, UT 84119  

NLE Websites -- All DOE Office Websites (Extended Search)

based Solid Oxide Fuel Cells based Solid Oxide Fuel Cells Ceramatec, Inc., Salt Lake City, UT 84119 S. (Elango) Elangovan, Joseph Hartvigsen, Insoo Bay, and Feng Zhao High efficiency operation is one of the primary attractions to use solid oxide fuel cells as the energy conversion device. High efficiency requires maximizing of the product of operating voltage and fuel utilization. The maximum possible operating voltage however is limited by the Nernst potential near the fuel exhaust. In oxygen conducting electrolyte based fuel cells (O-SOFC) as the fuel utilization increases, the Nernst potential continues to decrease with the dilution of fuel by the reaction products. In contrast, in a proton conducting electrolyte based fuel cell (P-SOFC) the reaction product is formed on the cathode side allowing for high operating voltage at high fuel

219

Solid oxide fuel cell with multi-unit construction and prismatic design  

DOE Patents (OSTI)

A single cell unit of a solid oxide fuel cell is described that is individually fabricated and sintered prior to being connected to adjacent cells to form a solid oxide fuel cell. The single cell unit is comprised of a shaped anode sheet positioned between a flat anode sheet and an anode-electrolyte-cathode (A/E/C) sheet, and a shaped cathode sheet positioned between the A/E/C sheet and a cathode-interconnect-anode (C/I/A) sheet. An alternate embodiment comprises a shaped cathode sheet positioned between an A/E/C sheet and a C/I/A sheet. The shaped sheets form channels for conducting reactant gases. Each single cell unit is individually sintered to form a finished sub-assembly. The finished sub-assemblies are connected in electrical series by interposing connective material between the end surfaces of adjacent cells, whereby individual cells may be inspected for defects and interchanged with non-defective single cell units. 7 figs.

McPheeters, C.C.; Dees, D.W.; Myles, K.M.

1999-03-16T23:59:59.000Z

220

Solid oxide fuel cell with multi-unit construction and prismatic design  

DOE Patents (OSTI)

A single cell unit of a solid oxide fuel cell that is individually fabricated and sintered prior to being connected to adjacent cells to form a solid oxide fuel cell. The single cell unit is comprised of a shaped anode sheet positioned between a flat anode sheet and an anode-electrolyte-cathode (A/E/C) sheet, and a shaped cathode sheet positioned between the A/E/C sheet and a cathode-interconnect-anode (C/I/A) sheet. An alternate embodiment comprises a shaped cathode sheet positioned between an A/E/C sheet and a C/I/A sheet. The shaped sheets form channels for conducting reactant gases. Each single cell unit is individually sintered to form a finished sub-assembly. The finished sub-assemblies are connected in electrical series by interposing connective material between the end surfaces of adjacent cells, whereby individual cells may be inspected for defects and interchanged with non-defective single cell units.

McPheeters, Charles C. (Naperville, IL); Dees, Dennis W. (Downers Grove, IL); Myles, Kevin M. (Downers Grove, IL)

1999-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "oxide fuel fabrication" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


221

Effect of Substrate Thickness on Oxide Scale Spallation for Solid Oxide Fuel Cells  

SciTech Connect

In this paper, the effect of the ferritic substrate's thickness on the delamination/spallation of the oxide scale was investigated experimentally and numerically. At the high-temperature oxidation environment of solid oxide fuel cells (SOFCs), a combination of growth stress with thermal stresses may lead to scale delamination/buckling and eventual spallation during SOFC stack cooling, even leading to serious degradation of cell performance. The growth stress is induced by the growth of the oxide scale on the scale/substrate interface, and thermal stress is induced by a mismatch of the coefficient of thermal expansion between the oxide scale and the substrate. The numerical results show that the interfacial shear stresses, which are the driving force of scale delamination between the oxide scale and the ferritic substrate, increase with the growth of the oxide scale and also with the thickness of the ferritic substrate; i.e., the thick ferritic substrate can easily lead to scale delamination and spallation. Experimental observation confirmed the predicted results of the delamination and spallation of the oxide scale on the ferritic substrate.

Liu, Wenning N.; Sun, Xin; Stephens, Elizabeth V.; Khaleel, Mohammad A.

2011-07-01T23:59:59.000Z

222

Electromotive Force for Solid Oxide Fuel Cells Using Biomass Produced Gas as Fuel  

Science Journals Connector (OSTI)

The electromotive force (e.m.f.) of solid oxide fuel cells using biomass produced gas (BPG) as the fuels is calculated at 700-1 200 K using an in-house computer program based on thermodynamic equilibrium analysis. Tour program also predicts the concentration of oxygen in the fuel chamber as well as the concentration of equilibrium species such as H2 CO CO2 and CH4. Compared with using hydrogen as a fuel the e.m.f. for cells using BPG as the fuels is relative low and strongly influenced by carbon deposition. To remove carbon deposition the optimum amount of H2O to add is determined at various operating temperatures. Further the e.m.f. for cells based on yttria stabilized zirconia and doped ceria as electrolytes are compared. The study reveals that when using BPG as fuel the depression of e.m.f. for a SOFC using doped ceria as electrolyte is relatively small when compared with that using Yttria stabilized zirconia.

Wei Zhu

2006-01-01T23:59:59.000Z

223

Impact of Fission Products Impurity on the Plutonium Content of Metal- and Oxide- Fuels in Sodium Cooled Fast Reactors  

SciTech Connect

This short report presents the neutronic analysis to evaluate the impact of fission product impurity on the Pu content of Sodium-cooled Fast Reactor (SFR) metal- and oxide- fuel fabrication. The similar work has been previously done for PWR MOX fuel [1]. The analysis will be performed based on the assumption that the separation of the fission products (FP) during the reprocessing of UOX spent nuclear fuel assemblies is not perfect and that, consequently, a certain amount of FP goes into the Pu stream used to fabricate SFR fuels. Only non-gaseous FPs have been considered (see the list of 176 isotopes considered in the calculations in Appendix 1 of Reference 1). Throughout of this report, we define the mixture of Pu and FPs as PuFP. The main objective of this analysis is to quantify the increase of the Pu content of SFR fuels necessary to maintain the same average burnup at discharge independently of the amount of FP in the Pu stream, i.e. independently of the PuFP composition. The FP losses are considered element-independent, i.e., for example, 1% of FP losses mean that 1% of all non-gaseous FP leak into the Pu stream.

Hikaru Hiruta; Gilles Youinou

2013-09-01T23:59:59.000Z

224

Thin-film heterostructure solid oxide fuel cells  

Science Journals Connector (OSTI)

A micro thin-filmsolid oxide fuel cell (TFSOFC) has been designed based on thin-filmdeposition and microlithographic processes. The TFSOFC is composed of a thin-filmelectrolyte grown on a nickel foil substrate and a thin-filmcathodedeposited on the electrolyte. The Ni foil substrate is then processed into a porous anode by photolithographic patterning and etching to develop pores for gas transport into the fuel cell. A La 0.5 Sr 0.5 CoO 3 (LSCO) thin-filmcathode is then deposited on the electrolyte and a porous NiO–YSZ cermet layer is added to the anode to improve the electrode performance. The TFSOFC has stably operated in a temperature ranges as low as 480–570?°C significantly lower than bulk SOFC’s and has yielded a maximum output power density of ?110? mW/cm 2 in that temperature range.

X. Chen; N. J. Wu; L. Smith; A. Ignatiev

2004-01-01T23:59:59.000Z

225

Architectures for individual and stacked micro single chamber solid oxide fuel cells  

E-Print Network (OSTI)

Solid oxide fuel cells (SOFCs) are electrochemical conversion devices that convert various fuel sources directly into electrical energy at temperatures ranging from 600°C to 1000°C. These high temperatures could potentially ...

Crumlin, Ethan J

2007-01-01T23:59:59.000Z

226

Mechanism of oxygen reduction reaction on transition metal oxide catalysts for high temperature fuel cells  

E-Print Network (OSTI)

The solid oxide fuel cell (SOFC) with its high energy conversion efficiency, low emissions, silent operation and its ability to utilize commercial fuels has the potential to create a large impact on the energy landscape. ...

La O', Gerardo Jose Cordova

2008-01-01T23:59:59.000Z

227

Design improvements of micro-tubular solid oxide fuel cells for unmanned aircraft applications.  

E-Print Network (OSTI)

??This work contributes to the development of a micro-tubular solid oxide fuel cell (mSOFC) stack for use in a small unmanned aerial vehicle. Fuel cells… (more)

Howe, Katie Sarah

2014-01-01T23:59:59.000Z

228

Thermal Cyclability of Reactive Air Braze Seals in Anode Supported Solid Oxide Fuel Cells  

SciTech Connect

The popularity of anode-supported solid oxide fuel cells (SOFC) has increased in tandem with the ability to fabricate thinner gas-tight yttrium-stabilized zirconia (YSZ) electrolyte layers, which can now be routinely produced on the order of 7 to 10 ?m thick. While this has significantly improved power output and decreased the required fuel cell operating temperatures, the ability to reliably seal fuel cells remains a concern. The seals must be hermetic and be robust enough to retain their hermeticity even under the extreme operating conditions of SOFCs. Perhaps the largest contributor to stresses experienced by the seal is the fact that the SOFC is an assembly of many different materials with different thermal expansion properties. Although every effort is made to minimize thermal expansion mismatches across the seals, the stresses developed during thermal cycling still jeopardize seal integrity. Reactive air brazing (RAB), a method of joining that employs a metallic, and therefore non-brittle, seal material has been used to seal electrolyte/anode bilayers, such as those in anode-supported SOFCs, to Crofer-22 alloy. The results of rupture strength testing will be reported for as-brazed and thermally cycled samples and the effect of thermal cycling on the RAB seal microstructure will be shown

Hardy, John S.; Darsell, Jens T.; Coyle, Christopher A.; Birnbaum, Jerome C.; Weil, K. Scott

2004-12-31T23:59:59.000Z

229

Passive Time Coincidence Measurements with HEU Oxide Fuel Pins  

SciTech Connect

Passive time coincidence measurements have been performed on highly enriched uranium (HEU) oxide fuel pins at the Idaho National Laboratory Power Burst Facility. These experiments evaluate HEU detection capability using passive coincidence counting when utilizing moderated 3He tubes. Data acquisition was performed with the Nuclear Material Identification System (NMIS) to calculate the neutron coincidence time distributions. The amounts of HEU measured were 1 kg, 4 kg, and 8 kg in sealed 55-gallon drums. Data collected with the 3He tubes also include passive measurement of 31 kg of depleted uranium (DU) in order to determine the ability to distinguish HEU from DU. This paper presents results from the measurements.

McConchie, Seth M [ORNL] [ORNL; Hausladen, Paul [ORNL] [ORNL; Mihalczo, John T [ORNL] [ORNL

2008-01-01T23:59:59.000Z

230

Safeguards and security concept for the Secure Automated Fabrication (SAF) and Liquid Metal Reactor (LMR) fuel cycle, SAF line technical support  

SciTech Connect

This report is a safeguards and security concept system review for the secure automated fabrication (SAF) and national liquid metal reactor (LMR) fuel programs.

Schaubert, V.J.; Remley, M.E.; Grantham, L.F.

1986-02-21T23:59:59.000Z

231

Oxidation states study of nickel in solid oxide fuel cell anode using x-ray full-field spectroscopic nano-tomography  

Science Journals Connector (OSTI)

Identifying the chemical state and coupling with morphological information in three dimensions are of great interest in energy storage materials which typically involve reduction-oxidation cycling and structural evolution. Here we apply x-ray nano-tomography with multiple x-ray energies to study oxidation states of nickel(Ni) and nickel oxide phases in Ni-yttria-stabilized zirconia (YSZ) a typical anodematerial of solid oxide fuel cells(SOFC). We present a method to quantitatively identify the nickel-based oxides from Ni-YSZ anodecomposite and obtain chemical mapping as well as associated microstructures at nanometer scale in three dimensions. NiO particles manually placed on a Ni-YSZ compositeanode were used for validation of the method while no nickel oxides were found to be present within the electrode structure as remnants of the cell fabrication process. The application of the method can be widely applied to energy storage materials including SOFCs Li-ion batteries and supercapacitors as well as other systems for oxidation and reduction study.

Yu-chen Karen Chen-Wiegart; William M. Harris; Jeffrey J. Lombardo; Wilson K. S. Chiu; Jun Wang

2012-01-01T23:59:59.000Z

232

Multi-Component and Multi-Dimensional Mathematical Modeling of Solid Oxide Fuel Cells.  

E-Print Network (OSTI)

??Solid oxide fuel cells (SOFCs) are solid-state ceramic cells, typically operating between 1073 K and 1273 K. Because of high operating temperature, SOFCs are mostly… (more)

Hussain, Mohammed Mujtaba

2008-01-01T23:59:59.000Z

233

Mechanochemically synthesized nanomaterials for intermediate temperature solid oxide fuel cell membranes.  

E-Print Network (OSTI)

??[Truncated abstract] In this dissertation an investigation into the utility of mechanochemically synthesized nanopowders for intermediate temperature solid oxide fuel cell components is reported. The… (more)

Hos, James Pieter

2005-01-01T23:59:59.000Z

234

Hydrogen Generation and Coke Formation over a Diesel Oxidation Catalyst under Fuel Rich Conditions  

Science Journals Connector (OSTI)

Hydrogen Generation and Coke Formation over a Diesel Oxidation Catalyst under Fuel Rich Conditions† ... Hydrogen production via hydrocarbon steam reforming and water gas shift reactions was investigated over a monolith-supported Pt-based diesel oxidation catalyst. ...

Meshari AL-Harbi; Jin-Yong Luo; Robert Hayes; Martin Votsmeier; William S. Epling

2010-12-08T23:59:59.000Z

235

Composite cathode based on yttria stabilized bismuth oxide for low-temperature solid oxide fuel cells  

Science Journals Connector (OSTI)

Composites consisting of silver and yttria stabilized bismuth oxide (YSB) have been investigated as cathodes for low-temperature honeycomb solid oxide fuel cells with stabilized zirconia as electrolytes. At 600?° C the interfacial polarization resistances of a porous YSB–Ag cathode is about 0.3??? cm 2 more than one order of magnitude smaller than those of other reported cathodes on stabilized zirconia. For example the interfacial resistances of a traditional YSZ–lanthanum maganites composite cathode is about 11.4??? cm 2 at 600?° C . Impedance analysis indicated that the performance of an YSB–Ag composite cathode fired at 850?° C for 2 h is severely limited by gas transport due to insufficient porosity. The high performance of the YSB–Ag cathodes is very encouraging for developing honeycomb fuel cells to be operated at temperatures below 600?° C .

Changrong Xia; Yuelan Zhang; Meilin Liu

2003-01-01T23:59:59.000Z

236

US-Russian collaboration in MPC & A enhancements at the Elektrostal Uranium Fuel-Fabrication Plant  

SciTech Connect

Enhancement of the nuclear materials protection, control, and accounting of (MPC&A) at the Elektrostal Machine-Building Plant (ELEMASH) has proceeded in two phases. Initially, Elektrostal served as the model facility at which to test US/Russian collaboration and to demonstrate MPC&A technologies available for safeguards enhancements at Russian facilities. This phase addressed material control and accounting (MC&A) in the low-enriched uranium (LEU) fuel-fabrication processes and the physical protection (PP) of part of the (higher-enrichment) breeder-fuel process. The second phase, identified later in the broader US/Russian agreement for expanded MPC&A cooperation. includes implementation of appropriate MC&A and PP systems in the breeder-fuel fabrication processes. Within the past year, an automated physical protection system has been installed and demonstrated in building 274, and an automated MC&A system has been designed and is being installed and will be tested in the LEU process. Attention has now turned to assuring longterm sustainability for the first phase and beginning MPC&A upgrades for the second phase. Sustainability measures establish the infrastructure for operation, maintenance, and repair of the installed systems-with US support for the lifetime of the US/Russian Agreement, but evolving toward full Russian operation of the system over the long term. For phase 2, which will address higher enrichments, projects have been identified to characterize the facilities, design MPC&A systems, procure appropriate equipment, and install and test final systems. One goal in phase 2 will be to build on initial work to create shared, plant-wide MPC&A assets for operation, maintenance, and evaluation of all safeguards systems.

Smith, H.; Murray, W.; Whiteson, R. [and others

1997-11-01T23:59:59.000Z

237

Cover and startup gas supply system for solid oxide fuel cell generator  

DOE Patents (OSTI)

A cover and startup gas supply system for a solid oxide fuel cell power generator is disclosed. Hydrocarbon fuel, such as natural gas or diesel fuel, and oxygen-containing gas are supplied to a burner. Combustion gas exiting the burner is cooled prior to delivery to the solid oxide fuel cell. The system mixes the combusted hydrocarbon fuel constituents with hydrogen which is preferably stored in solid form to obtain a non-explosive gas mixture. The system may be used to provide both non-explosive cover gas and hydrogen-rich startup gas to the fuel cell.

Singh, Prabhakar (Export, PA); George, Raymond A. (Pittsburgh, PA)

1999-01-01T23:59:59.000Z

238

Cover and startup gas supply system for solid oxide fuel cell generator  

DOE Patents (OSTI)

A cover and startup gas supply system for a solid oxide fuel cell power generator is disclosed. Hydrocarbon fuel, such as natural gas or diesel fuel, and oxygen-containing gas are supplied to a burner. Combustion gas exiting the burner is cooled prior to delivery to the solid oxide fuel cell. The system mixes the combusted hydrocarbon fuel constituents with hydrogen which is preferably stored in solid form to obtain a non-explosive gas mixture. The system may be used to provide both non-explosive cover gas and hydrogen-rich startup gas to the fuel cell. 4 figs.

Singh, P.; George, R.A.

1999-07-27T23:59:59.000Z

239

Polarization effects in intermediate temperature, anode-supported solid oxide fuel cells  

SciTech Connect

Anode-supported sold oxide fuel cells with yttria-stabilized zirconia (YSZ) electrolyte, Sr-doped LaMnO{sub 3} (LSM) + YSZ cathode, and Ni + YSZ anode were fabricated and their performance was evaluated between 650 and 800 C with humidified hydrogen as the fuel and air as the oxidant. Maximum power densities measured were {approximately} 1.8 W/cm{sup 2} at 800 C and {approximately} 0.82 W/cm{sup 2} at 650 C. Voltage (V) vs. current density (i) traces were nonlinear; V vs. i exhibited a concave-up curvature [d{sup 2}V/di{sup 2} {ge} 0] at low values of i and a convex-up curvature [d{sup 2}V/di{sup 2} {le} 0] at higher values of i, typical of many low temperature fuel cells. Analysis of concentration polarization based on transport of gaseous species through porous electrodes, in part, is used to explain nonlinear V vs. i traces. The effects of activation polarization in the Tafel limit are also included. It is shown that in anode-supported cells, the initial concave-up curvature can be due either to activation or concentration polarization, or both. By contrast, in cathode-supported cells, the initial concave-up curvature is entirely due to activation polarization. From the experimentally observed V vs. i traces for anode-supported cells, effective binary diffusivity of gaseous species on the anodic side was estimated to be between {approximately} 0.1 cm{sup 2}/s at 650 C and {approximately} 0.2 cm{sup 2}/s at 800 C. The area specific resistance of the cell (ohmic part), varied between {approximately} 0.18 {Omega} cm{sup 2} at 650 C and {approximately} 0.07 {Omega} cm{sup 2} at 800 C with an activation energy of {approximately} 65 kJ/mol.

Kim, J.W.; Virkar, A.V.; Fung, K.Z.; Mehta, K. [Univ. of Utah, Salt Lake City, UT (United States). Dept. of Materials Science and Engineering] [Univ. of Utah, Salt Lake City, UT (United States). Dept. of Materials Science and Engineering; Singhal, S.C. [Westinghouse Electric Corp., Pittsburgh, PA (United States)] [Westinghouse Electric Corp., Pittsburgh, PA (United States)

1999-01-01T23:59:59.000Z

240

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

SciTech Connect

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.

Leming, Andres

2003-06-16T23:59:59.000Z

Note: This page contains sample records for the topic "oxide fuel fabrication" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


241

Hydrogen Oxidation Reaction at the Ni/YSZ Anode of Solid Oxide Fuel Cells from First Principles  

Science Journals Connector (OSTI)

By means of ab initio simulations we here provide a comprehensive scenario for hydrogen oxidation reactions at the Ni/zirconia anode of solid oxide fuel cells. The simulations have also revealed that in the presence of water chemisorbed at the oxide surface, the active region for H oxidation actually extends beyond the metal/zirconia interface unraveling the role of water partial pressure in the decrease of the polarization resistance observed experimentally.

Clotilde S. Cucinotta; Marco Bernasconi; Michele Parrinello

2011-11-08T23:59:59.000Z

242

Internal Gas Pressure Behavior in Mixed-Oxide Fuel Rods Fuels During Irradiation  

Science Journals Connector (OSTI)

Fuel / Symposium on Theoretical Models for Predicting In-Reactor Performance of Fuel and Cladding Material

T. B. Burley; M. D. Freshley

243

Conditioning effects on La1-xSrxMnO3-Yttria stabilized Zirconia electrodes for thin-film solid oxide fuel cells  

E-Print Network (OSTI)

for Thin-Film Solid Oxide Fuel Cells You-Kee Lee a, *, Jung-performance of a solid oxide fuel cell (SOFC). LSM surfacethe development of solid oxide fuel cells (SOFCs) capable of

2002-01-01T23:59:59.000Z

244

Metallic Interconnects for Solid Oxide Fuel Cell: Performance of Reactive Element Oxide Coating During 10, 20 and 30 Months Exposure  

Science Journals Connector (OSTI)

One of challenges in improving the performance and cost-effectiveness of SOFCs (Solid Oxide Fuel Cells) is the development of suitable interconnect materials. Chromia-forming alloys and especially ferritic sta...

S. Fontana; S. Chevalier; G. Caboche

2012-12-01T23:59:59.000Z

245

NETL: News Release - Solid Oxide Fuel Cell Reaches One Year of Operations  

NLE Websites -- All DOE Office Websites (Extended Search)

January 31, 2000 January 31, 2000 Solid Oxide Fuel Cell Reaches One Year of Operations Netherlands Test Boosts Confidence for Commercial Introduction by 2004 An experimental all solid-state fuel cell - the possible prototype for a future "combustion-less" power plant - has passed a key milestone in a joint public-private development effort. Schematic Diagram of Tubular Solid Oxide Fuel Cell The Siemens Westinghouse solid oxide fuel cell is a tubular arrangement of concentric ceramic electrodes and a solid-state electrolyte. Siemens-Westinghouse Power Corp., headquartered in Orlando, FL, announced this week that its 100-kilowatt solid oxide fuel cell power system, the world's largest, has completed one year of total operating time, the longest any fuel cell of this type and size has run. The milestone marked

246

EA-0510: High-Temperature Solid Oxide Fuel Cell (Sofc) Generator  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

510: High-Temperature Solid Oxide Fuel Cell (Sofc) Generator 510: High-Temperature Solid Oxide Fuel Cell (Sofc) Generator Development Project (METC), Churchill, Pennsylvania EA-0510: High-Temperature Solid Oxide Fuel Cell (Sofc) Generator Development Project (METC), Churchill, Pennsylvania SUMMARY This EA evaluates the environmental impacts of a proposal to enter into a 5-year cooperative agreement with the Westinghouse Electric Corporation for the development of high-temperature solid oxide fuel cell generators near Pittsburgh, Pennsylvania. PUBLIC COMMENT OPPORTUNITIES None available at this time. DOCUMENTS AVAILABLE FOR DOWNLOAD August 1, 1991 EA-0510: Final Environmental Assessment High-Temperature Solid Oxide Fuel Cell (Sofc) Generator Development Project (METC) August 1, 1991 EA-0510: Finding of No Significant Impact

247

A novel method for preparing anode cermets for solid oxide fuel cells  

SciTech Connect

A new method for fabrication of metal-cermet anodes in solid-oxide fuel cells (SOFCs) has been developed. Highly porous, yttria-stabilized zirconia (YSZ) films were prepared using a mixture of zircon fibers (YSZp, Si-stabilized, and {lt}0.3% Si) and normal YSZ powders (YSZd). The films remained highly porous following calcination up to 1,550 C, after which either Cu or Ni could be incorporated by impregnation with the nitrate salts. For Cu cermets, the performance increased with metal loading to at least 40% Cu. At 800 C using H{sub 2} as the fuel and a 230 {micro}m, YSZ electrolyte, the current-voltage (I-V) curves for either a Cu- or Ni-cermet anode formed using this new method were found to be identical to the I-V curve for a Ni cermet formed using traditional methods. Scanning electron microscopy showed that the anode films remained porous even with addition of Cu, so that additional modification was possible. Tests of this concept through the addition of ceria by impregnation with the Ce(NO{sub 3}){sub 3} led to an additional increase in the cell performance.

Craciun, R.; Park, S.; Gorte, R.J.; Vohs, J.M.; Wang, C.; Worrell, W.L.

1999-11-01T23:59:59.000Z

248

A NOVEL INTEGRATED STACK APPROACH FOR REALIZING MECHANICALLY ROBUST SOLID OXIDE FUEL CELLS  

SciTech Connect

SOFCs are a very promising energy conversion technology for utilization of fossil fuels. The proposed project is to improve the viability of SOFCs by introducing a novel stacking geometry. The geometry involved has all active SOFC components and the interconnect deposited as thin layers on an electrically insulating support. This allows the choice of a support material that provides optimal mechanical toughness and thermal shock resistance. The supports are in the form of flattened tubes, providing relatively high strength, high packing densities, and minimizing the number of seals required. The integration of SOFCs and interconnects on the same support has several other advantages including the reduction of electrical resistances associated with pressure contacts between the cells and interconnects, relaxation of fabrication tolerances required for pressure contacts, reduction of ohmic losses, and reduction of interconnect conductivity requirements. In this report, we describe the processing methodologies that have been developed for fabricating the integrated solid oxide fuel cell (ISOFC), along with results on characterization of the component materials: support, electrolyte, anode, cathode, and interconnect. Screen printing was the primary processing method developed. A centrifugal casting technique was also developed for depositing thin 8 mol % yttrium stabilized zirconia (YSZ) electrolyte layers on porous NiO-YSZ anode substrates. Dense pinhole-free YSZ coatings were obtained by co-sintering the bi-layers at 1400 C. After depositing La{sub 0.8}Sr{sub 0.2}MnO{sub 3} (LSM)-YSZ cathodes, single SOFCs produced near-theoretical open-circuit voltages and power densities of 0.55 W/cm{sup 2} at 800 C. Initial stack operation results are also described.

Scott A. Barnett; Tammy Lai; Jiang Liu

2001-11-01T23:59:59.000Z

249

Plan offered to revive nukes. [US DOE would fabricate fuel from weapons for WNP-1 and 3  

SciTech Connect

This article discusses a new plan that would allow work to resume on two uncompleted nuclear power units in Washington state at a cost of $3.3 billion under an agreement with the federal government. If approved, the Department of Energy would fabricate plutonium from US and former Soviet Union weapons into fuel.

Not Available

1993-09-20T23:59:59.000Z

250

Heterogeneous electrocatalysis in porous cathodes of solid oxide fuel cells  

E-Print Network (OSTI)

A general physics-based model is developed for heterogeneous electrocatalysis in porous electrodes and used to predict and interpret the impedance of solid oxide fuel cells. This model describes the coupled processes of oxygen gas dissociative adsorption and surface diffusion of the oxygen intermediate to the triple phase boundary, where charge transfer occurs. The model accurately captures the Gerischer-like frequency dependence and the oxygen partial pressure dependence of the impedance of symmetric cathode cells. Digital image analysis of the microstructure of the cathode functional layer in four different cells directly confirms the predicted connection between geometrical properties and the impedance response. As in classical catalysis, the electrocatalytic activity is controlled by an effective Thiele modulus, which is the ratio of the surface diffusion length (mean distance from an adsorption site to the triple phase boundary) to the surface boundary layer length (square root of surface diffusivity div...

Fu, Y; Bertei, A; Qi, C; Mohanram, A; Pietras, J D; Bazant, M Z

2014-01-01T23:59:59.000Z

251

A Planar Anode -Supported Solid Oxide Fuel Cell Model with Internal Reforming of Natural Gas  

E-Print Network (OSTI)

1 A Planar Anode - Supported Solid Oxide Fuel Cell Model with Internal Reforming of Natural Gas of natural gas has been developed. The model simultaneously solves mass, energy transport equations emission level, and multiple fuel utilization. SOFC can operate with various kinds of fuels such as natural

Boyer, Edmond

252

Bipolar Plate-Supported Solid Oxide Fuel Cell J. D. Carter, T. Cruse, J. Ralph,  

E-Print Network (OSTI)

Bipolar Plate-Supported Solid Oxide Fuel Cell "TuffCell" J. D. Carter, T. Cruse, J. Ralph, R. Kumar, and D. Myers Argonne National Laboratory Argonne, IL 2003 Annual Review DOE Fuel Cells Program May 19;Metallic Bipolar-Plate-Supported SOFC Design (TuffCell) Fuel flow field (metal) Air flow field (metal

253

Effect of Transient Hydrogen Evolution/Oxidation Reactions on the OCV of Direct Methanol Fuel Cells  

E-Print Network (OSTI)

Effect of Transient Hydrogen Evolution/Oxidation Reactions on the OCV of Direct Methanol Fuel Cells in the mass transport of various species and electrochemical reactions in DMFCs compared with hydrogen- fueled of a direct methanol fuel cell DMFC was observed to undergo an overshoot before it stabilized during

Zhao, Tianshou

254

Hydrogen Peroxide as an Oxidant for Microfluidic Fuel Cells Erik Kjeang,a,c,  

E-Print Network (OSTI)

Hydrogen Peroxide as an Oxidant for Microfluidic Fuel Cells Erik Kjeang,a,c, * Alexandre G. Brolo, Victoria, British Columbia, Canada V8W 3P6 We demonstrate a microfluidic fuel cell incorporating hydrogen and exhibits a high standard reduction potential. It also enables fuel cell operation where natural convection

Brolo, Alexandre G.

255

PRESSURIZED SOLID OXIDE FUEL CELL/GAS TURBINE POWER SYSTEM  

SciTech Connect

Power systems based on the simplest direct integration of a pressurized solid oxide fuel cell (SOFC) generator and a gas turbine (GT) are capable of converting natural gas fuel energy to electric power with efficiencies of approximately 60% (net AC/LHV), and more complex SOFC and gas turbine arrangements can be devised for achieving even higher efficiencies. The results of a project are discussed that focused on the development of a conceptual design for a pressurized SOFC/GT power system that was intended to generate 20 MWe with at least 70% efficiency. The power system operates baseloaded in a distributed-generation application. To achieve high efficiency, the system integrates an intercooled, recuperated, reheated gas turbine with two SOFC generator stages--one operating at high pressure, and generating power, as well as providing all heat needed by the high-pressure turbine, while the second SOFC generator operates at a lower pressure, generates power, and provides all heat for the low-pressure reheat turbine. The system cycle is described, major system components are sized, the system installed-cost is estimated, and the physical arrangement of system components is discussed. Estimates of system power output, efficiency, and emissions at the design point are also presented, and the system cost of electricity estimate is developed.

W.L. Lundberg; G.A. Israelson; R.R. Moritz (Rolls-Royce Allison); S.E. Veyo; R.A. Holmes; P.R. Zafred; J.E. King; R.E. Kothmann (Consultant)

2000-02-01T23:59:59.000Z

256

Performance Analysis and Development Strategies for Solid Oxide Fuel Cells  

Science Journals Connector (OSTI)

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

E Ivers-Tiffée; A Leonide; A Weber

2011-01-01T23:59:59.000Z

257

Pulsed DD Neutron Generator Measurements for HEU Oxide Fuel Pins Using Liquid Scintillators with Pulse Shape Discrimination  

E-Print Network (OSTI)

measurements have been performed on high-enriched uranium (HEU) oxide fuel pins and depleted uranium metal

Pennycook, Steve

258

Integrating catalytic coal gasifiers with solid oxide fuel cells  

SciTech Connect

A review was conducted for coal gasification technologies that integrate with solid oxide fuel cells (SOFC) to achieve system efficiencies near 60% while capturing and sequestering >90% of the carbon dioxide [1-2]. The overall system efficiency can reach 60% when a) the coal gasifier produces a syngas with a methane composition of roughly 25% on a dry volume basis, b) the carbon dioxide is separated from the methane-rich synthesis gas, c) the methane-rich syngas is sent to a SOFC, and d) the off-gases from the SOFC are recycled back to coal gasifier. The thermodynamics of this process will be reviewed and compared to conventional processes in order to highlight where available work (i.e. exergy) is lost in entrained-flow, high-temperature gasification, and where exergy is lost in hydrogen oxidation within the SOFC. The main advantage of steam gasification of coal to methane and carbon dioxide is that the amount of exergy consumed in the gasifier is small compared to conventional, high temperature, oxygen-blown gasifiers. However, the goal of limiting the amount of exergy destruction in the gasifier has the effect of limiting the rates of chemical reactions. Thus, one of the main advantages of steam gasification leads to one of its main problems: slow reaction kinetics. While conventional entrained-flow, high-temperature gasifiers consume a sizable portion of the available work in the coal oxidation, the consumed exergy speeds up the rates of reactions. And while the rates of steam gasification reactions can be increased through the use of catalysts, only a few catalysts can meet cost requirements because there is often significant deactivation due to chemical reactions between the inorganic species in the coal and the catalyst. Previous research into increasing the kinetics of steam gasification will be reviewed. The goal of this paper is to highlight both the challenges and advantages of integrating catalytic coal gasifiers with SOFCs.

Siefert, N.; Shamsi, A.; Shekhawat, D.; Berry, D.

2010-01-01T23:59:59.000Z

259

Three-Dimensional Analysis of Solid Oxide Fuel Cell Ni-YSZ Anode Interconnectivity James R. Wilson,a  

E-Print Network (OSTI)

1 Three-Dimensional Analysis of Solid Oxide Fuel Cell Ni-YSZ Anode Interconnectivity James R of interconnectivity of solid-oxide fuel cell (SOFC) electrode phases. The method was applied to the three, and hence was not electrochemically active. #12;2 1. Introduction Attempts to understand solid oxide fuel

Kalies, William D.

260

CONTROL-ORIENTED MODELING OF A SOLID-OXIDE FUEL CELL STACK USING AN LPV MODEL STRUCTURE  

E-Print Network (OSTI)

CONTROL-ORIENTED MODELING OF A SOLID-OXIDE FUEL CELL STACK USING AN LPV MODEL STRUCTURE Borhan M dynamic model of a solid oxide fuel cell stack. Using a detailed physical model as a starting point, we (usually air) on the cathode side. Solid-oxide fuel cells (SOFCs) utilize a ceramic oxygen-ion conducting

Sanandaji, Borhan M.

Note: This page contains sample records for the topic "oxide fuel fabrication" from the National Library of EnergyBeta (NLEBeta).
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they are not comprehensive nor are they the most current set.
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to obtain the most current and comprehensive results.


261

In situ reduction and reoxidation of a solid oxide fuel cell anode in an environmental Q. Jeangros1  

E-Print Network (OSTI)

In situ reduction and reoxidation of a solid oxide fuel cell anode in an environmental TEM Q, Denmark Solid oxide fuel cells (SOFC) are efficient devices for the electrochemical conversion of a large, high fuel utilization or a shut down without protection gas. The important expansion during oxidation

Dunin-Borkowski, Rafal E.

262

IEEE TRANSACTIONS ON POWER ELECTRONICS, VOL. 19, NO. 5, SEPTEMBER 2004 1263 Solid-Oxide-Fuel-Cell Performance and Durability  

E-Print Network (OSTI)

IEEE TRANSACTIONS ON POWER ELECTRONICS, VOL. 19, NO. 5, SEPTEMBER 2004 1263 Solid-Oxide-Fuel-Cell of solid-oxide-fuel-cell (SOFC) power-conditioning system (PCS) at the subsystem/component and system Terms--Power-conditioning system (PCS), power-elec- tronics subsystem (PES), solid-oxide-fuel-cell (SOFC

Mazumder, Sudip K.

263

Journal of Power Sources 135 (2004) 184191 A solid oxide fuel cell system fed with hydrogen sulfide  

E-Print Network (OSTI)

Journal of Power Sources 135 (2004) 184­191 A solid oxide fuel cell system fed with hydrogen for a solid oxide fuel cell (SOFC). This paper presents an examination of a simple hydrogen sulfide and natural gas-fed solid oxide fuel cell system. The possibility of utilization of hydrogen sulfide

264

Original Research Article Influence of anodic gas recirculation on solid oxide fuel cells in a micro  

E-Print Network (OSTI)

Original Research Article Influence of anodic gas recirculation on solid oxide fuel cells utilization in the cell-stack should be reduced. Ă? 2014 Published by Elsevier Ltd. Introduction Solid-oxide Anode off-gas recycle a b s t r a c t The recycle of anode depleted gas has been employed in solid oxide

Nielsen, Mads Pagh

265

A model for waterside oxidation of zircaloy fuel cladding in pressurized water reactors  

SciTech Connect

A model is developed to simulate the oxidation of zircaloy fuel rod cladding exposed to pressurized water reactor operating conditions. The model is used to predict the oxidation rate for both ex- and in-reactor conditions in terms of the weight gain and oxide thickness. Comparisons of the model predictions with experimental data show very good agreement.

Amarshad, A.I.A. [Institute of Atomic Energy Research, Riyadh (Saudi Arabia); Klein, A.C. [Oregon State Univ., Corvallis, OR (United States)

1992-12-31T23:59:59.000Z

266

Novel Electrode Materials for Low-Temperature Solid-Oxide Fuel Cells  

SciTech Connect

Composites electrodes consisting of silver and bismuth vanadates exhibit remarkable catalytic activity for oxygen reduction at 500-550 C and greatly reduce the cathode-electrolyte (doped ceria) resistances of low temperature SOFCs, down to about 0.53 {omega}cm{sup 2} at 500 C and 0.21 {omega}cm{sup 2} at 550 C. The observed power densities of 231, 332, and 443 mWcm-2 at 500, 525 and 550 C, respectively, make it possible to operate SOFCs at temperatures about 500 C. Fuel cell performance depends strongly on the anode microstructure, which is determined by the anode compositions and fabrication conditions. Four types of anodes with two kinds of NiO and GDC powders were investigated. By carefully adjusting the anode microstructure, the GDC electrolyte/anode interfacial polarization resistances reduced dramatically. The interfacial resistance at 600 C decreased from 1.61 {omega} cm{sup 2} for the anodes prepared using commercially available powders to 0.06 {omega} cm{sup 2} for those prepared using powders derived from a glycine-nitrate process. Although steam reforming or partial oxidation is effective in avoiding carbon deposition of hydrocarbon fuels, it increases the operating cost and reduces the energy efficiency. Anode-supported SOFCs with an electrolyte of 20 {micro}m-thick Gd-doped ceria (GDC) were fabricated by co-pressing. A catalyst (1 %wt Pt dispersed on porous Gd-doped ceria) for pre-reforming of propane was developed with relatively low steam to carbon (S/C) ratio ({approx}0.5), coupled with direct utilization of the reformate in low-temperature SOFCs. Propane was converted to smaller molecules during pre-reforming, including H{sub 2}, CH{sub 4}, CO, and CO{sub 2}. A peak power density of 247 mW/cm{sup 2} was observed when pre-reformed propane was directly fed to an SOFC operated at 600 C. No carbon deposition was observed in the fuel cell for a continuous operation of 10 hours at 600 C. The ability of producing vastly different microstructures and morphologies of the very same material is critical to the fabrication of functionally graded electrodes for solid-state electrochemical devices such as SOFCs and lithium batteries. By carefully adjusting deposition parameters, we have successfully produced oxide nano-powders with the size of 30 {approx} 200 nm. Porous films with various microstructures and morphologies are also deposited on several substrates by systematic adjustment of the deposition parameters. Highly porous, excellently bonded and nano-structured electrodes fabricated by combustion CVD exhibit extremely high surface area and remarkable catalytic activities. Using in situ potential dependent FTIR emission spectroscopy, we have found evidence for two, possibly three distinct di-oxygen species present on the electrode surface. We have successfully identified which surface oxygen species is present under a particular electrical or chemical condition and have been able to deduce the reaction mechanisms. This technique will be used to probe the gas-solid interactions at or near the TPB and on the surfaces of mixed-conducting electrodes in an effort to understand the molecular processes relevant to the intrinsic catalytic activity. Broad spectral features are assigned to the electrochemical-polarization-induced changes in the optical properties of the electrode surface layer.

Shaowu Zha; Meilin Liu

2005-03-23T23:59:59.000Z

267

LOW-TEMPERATURE, ANODE-SUPPORTED HIGH POWER DENSITY SOLID OXIDE FUEL CELLS WITH NANOSTRUCTURED ELECTRODES  

SciTech Connect

This report summarizes the work done during the entire project period, between October 1, 1999 and March 31, 2003, which includes a six-month no-cost extension. During the project, eight research papers have, either been, published, accepted for publication, or submitted for publication. In addition, several presentations have been made in technical meetings and workshops. The project also has provided support for four graduate students working towards advanced degrees. The principal technical objective of the project was to analyze the role of electrode microstructure on solid oxide fuel cell performance. Prior theoretical work conducted in our laboratory demonstrated that the particle size of composite electrodes has a profound effect on cell performance; the finer the particle size, the lower the activation polarization, the better the performance. The composite cathodes examined consisted of electronically conducting perovskites such as Sr-doped LaMnO{sub 3} (LSM) or Sr-doped LaCoO{sub 3} (LSC), which is also a mixed conductor, as the electrocatalyst, and yttria-stabilized zirconia (YSZ) or rare earth oxide doped CeO{sub 2} as the ionic conductor. The composite anodes examined were mixtures of Ni and YSZ. A procedure was developed for the synthesis of nanosize YSZ by molecular decomposition, in which unwanted species were removed by leaching, leaving behind nanosize YSZ. Anode-supported cells were made using the as-synthesized powders, or using commercially acquired powders. The electrolyte was usually a thin ({approx}10 microns), dense layer of YSZ, supported on a thick ({approx}1 mm), porous Ni + YSZ anode. The cathode was a porous mixture of electrocatalyst and an ionic conductor. Most of the cell testing was done at 800 C with hydrogen as fuel and air as the oxidant. Maximum power densities as high as 1.8 W/cm{sup 2} were demonstrated. Polarization behavior of the cells was theoretically analyzed. A limited amount of cell testing was done using liquid hydrocarbon fuels where reforming was achieved internally. Significant polarization losses also occur at the anode, especially at high fuel utilizations. An analysis of polarization losses requires that various contributions are isolated, and their dependence on pertinent parameters is quantitatively described. An investigation of fuel composition on gas transport through porous anodes was investigated and the role of fuel diluents was explored. This work showed that the molecular weight of the diluent has a significant effect on anode concentration polarization. This further showed that the presence of some molecular hydrogen is necessary to minimize polarization losses. Theoretical analysis has shown that the electrode microstructure has a profound effect on cell performance. In a series of experiments, cathode microstructural parameters were varied, without altering other parameters. Cathode microstructural parameters, especially three phase boundary (TPB) length, were estimated using techniques in quantitative stereology. Cell performance was quantitatively correlated with the relevant microstructural parameters, and charge transfer resistivity was explicitly evaluated. This is the first time that a fundamental parameter, which governs the activation polarization, has been quantitatively determined. An important parameter, which governs the cathodic activation polarization, and thus cell performance, is the ionic conductivity of the composite cathode. The traditional composite cathode is a mixture of LSM and YSZ. It is well known that Sr and Mg-doped LaGaO{sub 3} (LSGM), exhibits higher oxygen ion conductivity compared to YSZ. Cells were fabricated with composite cathodes comprising a mixture of LSM and LSGM. Studies demonstrated that LSGM-based composite cathodes exhibit excellent behavior. Studies have shown that Ni + YSZ is an excellent anode. In fact, in most cells, the principal polarization losses, at least at low fuel utilizations, are associated with the cathode. Theoretical analysis conducted in our group has also shown that anode-supported cells exhibi

Professor Anil V. Virkar

2003-05-23T23:59:59.000Z

268

Solid Oxide Fuel Cell Successfully Powers Truck Cab and Sleeper in  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Solid Oxide Fuel Cell Successfully Powers Truck Cab and Sleeper in Solid Oxide Fuel Cell Successfully Powers Truck Cab and Sleeper in DOE-Sponsored Test Solid Oxide Fuel Cell Successfully Powers Truck Cab and Sleeper in DOE-Sponsored Test March 19, 2009 - 1:00pm Addthis Washington, DC --In a test sponsored by the U.S. Department of Energy (DOE), a Delphi auxiliary power unit employing a solid oxide fuel cell (SOFC) successfully operated the electrical system and air conditioning of a Peterbilt Model 386 truck under conditions simulating idling conditions for 10 hours. The device provides an alternative to running a truck's main diesel engine, or using a truck's batteries, to power auxiliary electrical loads during rest periods, thereby lowering emissions, reducing noise, and saving fuel. In testing at Peterbilt Motors Company Texas head-quarters, a Delphi

269

Molten salt extraction of transuranic and reactive fission products from used uranium oxide fuel  

DOE Patents (OSTI)

Used uranium oxide fuel is detoxified by extracting transuranic and reactive fission products into molten salt. By contacting declad and crushed used uranium oxide fuel with a molten halide salt containing a minor fraction of the respective uranium trihalide, transuranic and reactive fission products partition from the fuel to the molten salt phase, while uranium oxide and non-reactive, or noble metal, fission products remain in an insoluble solid phase. The salt is then separated from the fuel via draining and distillation. By this method, the bulk of the decay heat, fission poisoning capacity, and radiotoxicity are removed from the used fuel. The remaining radioactivity from the noble metal fission products in the detoxified fuel is primarily limited to soft beta emitters. The extracted transuranic and reactive fission products are amenable to existing technologies for group uranium/transuranic product recovery and fission product immobilization in engineered waste forms.

Herrmann, Steven Douglas

2014-05-27T23:59:59.000Z

270

US-Russian collaboration for enhancing nuclear materials protection, control, and accounting at the Elektrostal uranium fuel-fabrication plant  

SciTech Connect

In September 1993, an implementing agreement was signed that authorized collaborative projects to enhance Russian national materials control and accounting, physical protection, and regulatory activities, with US assistance funded by the Nunn-Lugar Act. At the first US-Russian technical working group meeting in Moscow in February 1994, it was decided to identify a model facility where materials protection, control, and accounting (MPC and A) and regulatory projects could be carried out using proven technologies and approaches. The low-enriched uranium (LEU or RBMK and VVER) fuel-fabrication process at Elektrostal was selected, and collaborative work began in June 1994. Based on many factors, including initial successes at Elektrostal, the Russians expanded the cooperation by proposing five additional sites for MPC and A development: the Elektrostal medium-enriched uranium (MEU or BN) fuel-fabrication process and additional facilities at Podolsk, Dmitrovgrad, Obninsk, and Mayak. Since that time, multilaboratory teams have been formed to develop and implement MPC and A upgrades at the additional sites, and much new work is underway. This paper summarizes the current status of MPC and A enhancement projects in the LEU fuel-fabrication process and discusses the status of work that addresses similar enhancements in the MEU (BN) fuel processes at Elektrostal, under the recently expanded US-Russian MPC and A cooperation.

Smith, H. [Los Alamos National Lab., NM (United States); Allentuck, J. [Brookhaven National Lab., Upton, NY (United States); Barham, M. [Oak Ridge National Lab., TN (United States); Bishop, M. [Sandia National Labs., Albuquerque, NM (United States); Wentz, D. [Lawrence Livermore National Lab., CA (United States); Steele, B.; Bricker, K. [Pacific Northwest National Lab., Richland, WA (United States); Cherry, R. [USDOE, Washington, DC (United States); Snegosky, T. [Dept. of Defense, Washington, DC (United States). Defense Nuclear Agency

1996-09-01T23:59:59.000Z

271

Functionally Graded Cathodes for Solid Oxide Fuel Cells  

SciTech Connect

One primary suspected cause of long-term performance degradation of solid oxide fuels (SOFCs) is the accumulation of chromium (Cr) species at or near the cathode/electrolyte interface due to reactive Cr molecules originating from Cr-containing components (such as the interconnect) in fuel cell stacks. To date, considerable efforts have been devoted to the characterization of cathodes exposed to Cr sources; however, little progress has been made because a detailed understanding of the chemistry and electrochemistry relevant to the Cr-poisoning processes is still lacking. This project applied multiple characterization methods - including various Raman spectroscopic techniques and various electrochemical performance measurement techniques - to elucidate and quantify the effect of Cr-related electrochemical degradation at the cathode/electrolyte interface. Using Raman microspectroscopy the identity and location of Cr contaminants (SrCrO{sub 4}, (Mn/Cr){sub 3}O{sub 4} spinel) have been observed in situ on an LSM cathode. These Cr contaminants were shown to form chemically (in the absence of current flowing through the cell) at temperatures as low as 625 C. While SrCrO{sub 4} and (Mn/Cr){sub 3}O{sub 4} spinel must preferentially form on LSM, since the LSM supplies the Sr and Mn cations necessary for these compounds, LSM was also shown to be an active site for the deposition of Ag{sub 2}CrO{sub 4} for samples that also contained silver. In contrast, Pt and YSZ do not appear to be active for formation of Cr-containing phases. The work presented here supports the theory that Cr contamination is predominantly chemically-driven and that in order to minimize the effect, cathode materials should be chosen that are free of cations/elements that could preferentially react with chromium, including silver, strontium, and manganese.

Harry Abernathy; Meilin Liu

2006-12-31T23:59:59.000Z

272

Method of fabricating a monolithic core for a solid oxide fuela cell  

DOE Patents (OSTI)

A method is disclosed for forming a core for use in a solid oxide fuel cell that electrochemically combines fuel and oxidant for generating galvanic output. The core has an array of electrolyte and interconnect walls that are substantially devoid of any composite inert materials for support consisting instead only of the active anode, cathode, electrolyte and interconnect materials. Each electrolyte wall consists of cathode and anode materials sandwiching electrolyte material therebetween, and each interconnect wall consists of the cathode and anode materials sandwiching interconnect material therebetween. The electrolyte and interconnect walls define a plurality of substantially parallel core passageways alternately having respectively the inside faces thereof with only the anode material or with only the cathode material exposed. In the wall structure, the electrolyte and interconnect materials are only 0.002 to 0.01 cm thick; and the cathode and anode materials are only 0.002 to 0.05 cm thick. The method consists of building up the electrolyte and interconnect walls by depositing each material on individually and endwise of the wall itself, where each material deposit is sequentially applied for one cycle; and where the depositing cycle is repeated many times until the material buildup is sufficient to formulate the core. The core is heat cured to become dimensionally and structurally stable.

Zwick, S.A.; Ackerman, J.P.

1983-10-12T23:59:59.000Z

273

Fuel Composition Effects and Other Operational Parameters on Solid Oxide Fuel Cell Performance  

NLE Websites -- All DOE Office Websites (Extended Search)

Composition Effects and Other Composition Effects and Other Operational Parameters on Solid Oxide Fuel Cell Performance DOE/NETL-401/093010 September 30, 2010 Disclaimer This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference therein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or

274

Autothermal and partial oxidation reformer-based fuel processor, method for improving catalyst function in autothermal and partial oxidation reformer-based processors  

DOE Patents (OSTI)

The invention provides a fuel processor comprising a linear flow structure having an upstream portion and a downstream portion; a first catalyst supported at the upstream portion; and a second catalyst supported at the downstream portion, wherein the first catalyst is in fluid communication with the second catalyst. Also provided is a method for reforming fuel, the method comprising contacting the fuel to an oxidation catalyst so as to partially oxidize the fuel and generate heat; warming incoming fuel with the heat while simultaneously warming a reforming catalyst with the heat; and reacting the partially oxidized fuel with steam using the reforming catalyst.

Ahmed, Shabbir; Papadias, Dionissios D.; Lee, Sheldon H. D.; Ahluwalia, Rajesh K.

2013-01-08T23:59:59.000Z

275

Effects of an oxidizing atmosphere in a spent fuel packaging facility  

SciTech Connect

Sufficient oxidation of spent fuel can cause a cladding breach to propagate, resulting in dispersion of fuel particulates and gaseous radionuclides. The literature for spent fuel oxidation in storage and disposal programs was reviewed to evaluate the effect of an oxidizing atmosphere in a preclosure packaging facility on (1) physical condition of the fuel and (2) operations in the facility. Effects such as cladding breach propagation, cladding oxidation, rod dilation, fuel dispersal, {sup 14}C and {sup 85}Kr release, and crud release were evaluated. The impact of these effects, due to oxidation, upon a spent fuel handling facility is generally predicted to be less than the impact of similar effects due to fuel rod breached during handling in an inert-atmosphere facility. Preliminary temperature limits of 240{degree}C and 227{degree}C for a 2-week or 4-week handling period and 175{degree}C for 2-year lag storage would prevent breach propagation and fuel dispersal. Additional data that are needed to support the assumptions in this analysis or complete the database were identified.

Einziger, R.E.

1991-09-01T23:59:59.000Z

276

Comparative Study of Laboratory-Scale and Prototypic Production-Scale Fuel Fabrication Processes and Product Characteristics  

SciTech Connect

Abstract – An objective of the High Temperature Gas Reactor fuel development and qualification program for the United States Department of Energy has been to qualify fuel fabricated in prototypic production-scale equipment. The quality and characteristics of the tristructural isotropic coatings on fuel kernels are influenced by the equipment scale and processing parameters. Some characteristics affecting product quality were suppressed while others have become more significant in the larger equipment. Changes to the composition and method of producing resinated graphite matrix material has eliminated the use of hazardous, flammable liquids and enabled it to be procured as a vendor-supplied feed stock. A new method of overcoating TRISO particles with the resinated graphite matrix eliminates the use of hazardous, flammable liquids, produces highly spherical particles with a narrow size distribution, and attains product yields in excess of 99%. Compact fabrication processes have been scaled-up and automated with relatively minor changes to compact quality to manual laboratory-scale processes. The impact on statistical variability of the processes and the products as equipment was scaled are discussed. The prototypic production-scale processes produce test fuels that meet fuel quality specifications.

Douglas W. Marshall

2014-10-01T23:59:59.000Z

277

New Sealing Concept for Planar Solid Oxide Fuel Cells  

SciTech Connect

A key element in developing high performance planar solid oxide fuel cell stacks is the hermetic seal between the metal and ceramic components. There are two methods of sealing that are commonly employed: (1) rigid joining or (2) compressive sealing. Each method has its own set of advantages and design constraints. An alternative approach is currently under development that appears to combine some of the advantages of the other two techiques, including hermeticity, mechanical integrity, and minimization of interfacial stresses in either of the joint substrate materials, particulary the ceramic. The new sealing concept relies on a plastically deformable metal seal; one that offers a quasi-dynamic mechanical response in that it is adherent to both sealing surfaces, i.e. non-sliding, but readily yields or deforms under thermally generated stresses, thereby mitigating the development of stresses in the adjacent ceramic and metal components even when a significant difference in thermal expansion exists between the two materials. The pre-experimental design of the seal, initial proof-of-principle results on small test specimens, and finite element analyses aimed at scaling the seal to prototypical sizes and geometries are described herein.

Weil, K. Scott; Hardy, John S.; Koeppel, Brian J.

2006-08-01T23:59:59.000Z

278

Formation of thin walled ceramic solid oxide fuel cells  

DOE Patents (OSTI)

To reduce thermal stress and improve bonding in a high temperature monolithic solid oxide fuel cell (SOFC), intermediate layers are provided between the SOFC's electrodes and electrolyte which are of different compositions. The intermediate layers are comprised of a blend of some of the materials used in the electrode and electrolyte compositions. Particle size is controlled to reduce problems involving differential shrinkage rates of the various layers when the entire structure is fired at a single temperature, while pore formers are provided in the electrolyte layers to be removed during firing for the formation of desired pores in the electrode layers. Each layer includes a binder in the form of a thermosetting acrylic which during initial processing is cured to provide a self-supporting structure with the ceramic components in the green state. A self-supporting corrugated structure is thus formed prior to firing, which the organic components of the binder and plasticizer removed during firing to provide a high strength, high temperature resistant ceramic structure of low weight and density.

Claar, Terry D. (Tisle, IL); Busch, Donald E. (Hinsdale, IL); Picciolo, John J. (Lockport, IL)

1989-01-01T23:59:59.000Z

279

Electrical Generation for More-Electric Aircraft using Solid Oxide Fuel Cells  

NLE Websites -- All DOE Office Websites (Extended Search)

XXXXX XXXXX Prepared for the U.S. Department of Energy under Contract DE-AC05-76RL01830 Electrical Generation for More-Electric Aircraft using Solid Oxide Fuel Cells GA Whyatt LA Chick April 2012 PNNL-XXXXX Electrical Generation for More- Electric Aircraft using Solid Oxide Fuel Cells GA Whyatt LA Chick April 2012 Prepared for the U.S. Department of Energy under Contract DE-AC05-76RL01830 Pacific Northwest National Laboratory Richland, Washington 99352 iii Summary This report examines the potential for Solid-Oxide Fuel Cells (SOFC) to provide electrical generation on-board commercial aircraft. Unlike a turbine-based auxiliary power unit (APU) a solid oxide fuel cell power unit (SOFCPU) would be more efficient than using the main engine generators to generate

280

Comparative Life-Cycle Assessment of Residential Heating Systems, Focused on Solid Oxide Fuel Cells  

Science Journals Connector (OSTI)

This study aims to analyze a Solid Oxide Fuel Cell (SOFC) for residential heating applications by...producer, the user as an individual and the user...intended as the heating demand of a building, applied by defa...

Alba Cánovas; Rainer Zah; Santiago Gassó

2013-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "oxide fuel fabrication" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


281

Increasing the CO tolerance of PEM fuel cells via current pulsing and self-oxidation  

E-Print Network (OSTI)

An investigation was conducted to determine and compare the effect of cell current pulsing and "self-oxidation" in increasing the CO tolerance of a PEM fuel cell. The most effective pulsing parameter values were also determined. Current pulsing...

Thomason, Arthur Hugh

2004-09-30T23:59:59.000Z

282

Assessment of an Industrial Wet Oxidation System for Burning Waste and Low-Grade Fuels  

E-Print Network (OSTI)

"Stone & Webster Engineering Corporation, under Department of Energy sponsorship, is developing a wet oxidation system to generate steam for industrial processes by burning industrial waste materials and low-grade fuels. The program involves...

Bettinger, J.; Koppel, P.; Margulies, A.

283

Seven Projects That Will Advance Solid Oxide Fuel Cell Research Selected by  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

That Will Advance Solid Oxide Fuel Cell Research That Will Advance Solid Oxide Fuel Cell Research Selected by DOE for Further Development Seven Projects That Will Advance Solid Oxide Fuel Cell Research Selected by DOE for Further Development July 27, 2012 - 1:00pm Addthis Washington, D.C. - Seven projects that will help develop low-cost solid oxide fuel cell (SOFC) technology for environmentally responsible central power generation from the Nation's abundant fossil energy resources have been selected for further research by the Department of Energy (DOE). The projects, managed by the Office of Fossil Energy's National Energy Technology Laboratory (NETL), are valued at a total of $4,391,570, with DOE contributing $3,499,250 and the remaining cost provided by the recipients. Four of the selected projects will pursue advances in cathode performance,

284

Apparatus tube configuration and mounting for solid oxide fuel cells  

DOE Patents (OSTI)

A generator apparatus (10) is made containing long, hollow, tubular, fuel cells containing an inner air electrode (64), an outer fuel electrode (56), and solid electrolyte (54) therebetween, placed between a fuel distribution board (29) and a board (32) which separates the combustion chamber (16) from the generating chamber (14), where each fuel cell has an insertable open end and in insertable, plugged, closed end (44), the plugged end being inserted into the fuel distribution board (29) and the open end being inserted through the separator board (32) where the plug (60) is completely within the fuel distribution board (29).

Zymboly, Gregory E. (Murrysville, PA)

1993-01-01T23:59:59.000Z

285

Innovative Self-Healing Seals for Solid Oxide Fuel Cells (SOFCs) University of Cincinnati  

NLE Websites -- All DOE Office Websites (Extended Search)

Innovative Self-Healing Seals for Solid Innovative Self-Healing Seals for Solid Oxide Fuel Cells (SOFCs)-University of Cincinnati Background The mission of the U.S. Department of Energy (DOE) National Energy Technology Laboratory (NETL) is to advance energy options to fuel our economy, strengthen our security, and improve our environment. With the Solid State Energy Conversion Alliance (SECA), NETL is leading the research, development, and demonstration of solid oxide

286

Insights into CO poisoning in high performance proton-conducting solid oxide fuel cells  

Science Journals Connector (OSTI)

Abstract High performance anode supported proton-conducting solid oxide fuel cells (PC-SOFC) were fabricated and their performance in syngas was studied. PC-SOFC button cells produced a maximum power density of 812 mW cm?2 in H2 at 750 °C. It was found that the CO-containing feed streams could drastically degrade the performance of PC-SOFC. Based on the experimental results and the theoretical analysis, the detailed process of the CO-induced Ni catalyst deactivation was identified. This process could be divided into three distinguishable stages during the continuous exposure of the Ni catalyst in the CO-containing environment. The first stage could be described using the CO surface active site blocking mechanism, which was further confirmed by CO/H2 competitive adsorption model. The second stage deactivation was proposed to be related to the carbon deposition at TPB (Triple-phase Boundary). The deactivation during this stage was accelerated by the electrochemical conversion of H2. The last stage was attributed to the coking of Ni catalyst and the resulted metal dusting effect.

Ning Yan; Xian-Zhu Fu; Karl T. Chuang; Jing-Li Luo

2014-01-01T23:59:59.000Z

287

A reduced temperature solid oxide fuel cell with three-dimensionally ordered macroporous cathode  

SciTech Connect

Three-dimensionally ordered macroporous cathode was fabricated for a zirconia based micro-tubular solid oxide fuel cells (SOFCs). Three different cathodes (cathode A, no pore former; cathode B, with pore former (1.5 {micro}m in diameter); cathode C, with pore former (0.8 {micro}m in diameter)) were compared to investigate how the microstructure of it affected the cell performance at various operating temperatures. Micro-sized pores were well distributed within cathode B and C. The total porosity of cathode A is 35%, while it respectively reached 42 and 50% for cathodes B and C. At the same time, the specific surface area of them was 28.8 and 52.0% larger than that of the cathode A. As a result, the peak power density of the zirconia based cell, with cathode C, was 0.25 and 0.56 W cm{sup -2} at 550 and 600 C, while the respective value was just 0.11 and 0.30 W cm{sup -2} for the cell with cathode A. Thus, optimizing microstructure of cathode should be one of the best approaches for lowering the operating temperature for SOFCs.

Liang, B.; Suzuki, T.; Hamamoto, K.; Yamaguchi, T.; Sumi, H.; Fujishiro, Y.; Ingram, B. J.; Carter, J. D. (Chemical Sciences and Engineering Division); (National Institute of Advanced Industrial Science and Technology)

2012-01-01T23:59:59.000Z

288

Numerical Modeling of the Distributed Electrochemistry and Performance of Solid Oxide Fuel Cells  

SciTech Connect

A cell-level distributed electrochemistry (DEC) modeling tool has been developed to enable prediction of solid oxide fuel cell performance by considering the coupled and spatially varying multi-physics that occur within the tri-layer. The approach calculates the distributed electrochemistry within the electrodes, which includes the charge transfer and electric potential fields, ion transport throughout the tri-layer, and gas distributions within the composite and porous electrodes. The thickness of the electrochemically active regions within the electrodes is calculated along with the distributions of charge transfer. The DEC modeling tool can examine the overall SOFC performance based on electrode microstructural parameters, such as particle size, pore size, porosity factor, electrolyte and electrode phase volume fractions, and triple-phase-boundary length. Recent developments in electrode fabrication methods have lead to increased interest in using graded and nano-structured electrodes to improve the electrochemical performance of SOFCs. This paper demonstrates how the DEC modeling tool can be used to help design novel electrode microstructures by optimizing a graded anode for high electrochemical performance.

Recknagle, Kurtis P.; Ryan, Emily M.; Khaleel, Mohammad A.

2011-12-01T23:59:59.000Z

289

Innovative Self-Healing Seals for Solid Oxide Fuel Cells (SOFC)  

SciTech Connect

Solid oxide fuel cell (SOFC) technology is critical to several national initiatives. Solid State Energy Conversion Alliance (SECA) addresses the technology needs through its comprehensive programs on SOFC. A reliable and cost-effective seal that works at high temperatures is essential to the long-term performance of the SOFC for 40,000 hours at 800°C. Consequently, seals remain an area of highest priority for the SECA program and its industry teams. An innovative concept based on self-healing glasses was advanced and successfully demonstrated through seal tests for 3000 hours and 300 thermal cycles to minimize internal stresses under both steady state and thermal transients for making reliable seals for the SECA program. The self-healing concept requires glasses with low viscosity at the SOFC operating temperature of 800°C but this requirement may lead to excessive flow of the glass in areas forming the seal. To address this challenge, a modification to glass properties by addition of particulate fillers is pursued in the project. The underlying idea is that a non-reactive ceramic particulate filler is expected to form glass-ceramic composite and increase the seal viscosity thereby increasing the creep resistance of the glass-composite seals under load. The objectives of the program are to select appropriate filler materials for making glass-composite, fabricate glass-composites, measure thermal expansion behaviors, and determine stability of the glass-composites in air and fuel environments of a SOFC. Self-healing glass-YSZ composites are further developed and tested over a longer time periods under conditions typical of the SOFCs to validate the long-term stability up to 2000 hours. The new concepts of glass-composite seals, developed and nurtured in this program, are expected to be cost-effective as these are based on conventional processing approaches and use of the inexpensive materials.

Raj Singh

2012-06-30T23:59:59.000Z

290

Update on uranium-molybdenum fuel foil fabrication development activities at the Y-12 National Security Complex in 2007  

SciTech Connect

In support of the RERTR Program, efforts are underway at Y-12 to develop and validate a production oriented, monolithic uranium molybdenum (U-Mo) foil fabrication process adaptable for potential implementation in a manufacturing environment. These efforts include providing full-scale prototype depleted and enriched U-Mo foils in support of fuel qualification testing. The work has three areas of focus; develop and demonstrate a feasible foil fabrication process utilizing depleted uranium-molybdenum (DU-Mo) source material, transition these production techniques to enriched uranium (EU-Mo) source material, and evaluate full-scale implementation of the developed production techniques. In 2006, Y-12 demonstrated successful fabrication of full-size DU-10Mo foils. In 2007, Y-12 activities were expanded to include continued DU-Mo foil fabrication with a focus on process refinement, source material impurity effects (specifically carbon), and the feasibility of physical vapor deposition (PVD) on DU-10Mo mini-foils. FY2007 activities also included a transition to EU-Mo and fabrication of full-size enriched foils. The purpose of this report is to update the RERTR audience on Y-12 efforts in 2007 that support the overall RERTR Program goals. (author)

DeMint, Amy; Gooch, Jack [Technology Development, Y-12 National Security Complex, Oak Ridge, TN 37830 (United States); Dunavant, Randy J.; Andes, Trent C. [National Security Programs, Y-12 National Security Complex, Oak Ridge, TN 37830 (United States)

2008-07-15T23:59:59.000Z

291

Ternary PtSnRhSnO2 nanoclusters: synthesis and electroactivity for ethanol oxidation fuel cell reaction  

E-Print Network (OSTI)

Ternary PtSnRh­SnO2 nanoclusters: synthesis and electroactivity for ethanol oxidation fuel cell a superior long-term activity and stability towards ethanol oxidation than the commercial Pt catalyst. Our. Ethanol becomes an attractive fuel in the fuel cell reactions compared with methanol and hydrogen, because

Frenkel, Anatoly

292

Engineering Organic/inorganic hybrids comprise a mixture of oxide  

E-Print Network (OSTI)

examine the current status of using organic/inorganic hybrids in fabrication of solid oxide fuel cells, and reactions on solid oxide fuel cell catalysts. The objectives of his research program are (i) developing of potential applications in coatings, fuel cells, solar cells, and sensors. Organic amino (-NH2) silane

293

Low Temperature Constrained Sintering of Cerium Gadolinium OxideFilms for Solid Oxide Fuel Cell Applications  

SciTech Connect

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 Ce{sub 0.9}Gd{sub 0.1}O{sub 1.95}, and to evaluate whether they could be used to produce dense, constrained Ce{sub 0.9}Gd{sub 0.1}O{sub 1.95} films at temperatures below 1000 C. To find the optimal sintering aid, Ce{sub 0.9}Gd{sub 0.1}O{sub 1.95} 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 Li{sub 2}O-Gd{sub 2}O{sub 3}-CeO{sub 2} 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.

Nicholas, Jason.D.

2007-06-30T23:59:59.000Z

294

Cathode and electrolyte materials for solid oxide fuel cells and ion transport membranes  

DOE Patents (OSTI)

Novel cathode, electrolyte and oxygen separation materials are disclosed that operate at intermediate temperatures for use in solid oxide fuel cells and ion transport membranes based on oxides with perovskite related structures and an ordered arrangement of A site cations. The materials have significantly faster oxygen kinetics than in corresponding disordered perovskites.

Jacobson, Allan J; Wang, Shuangyan; Kim, Gun Tae

2014-01-28T23:59:59.000Z

295

Application of Self-Propagating High Temperature Synthesis to the Fabrication of Actinide Bearing Nitride and Other Ceramic Nuclear Fuels  

SciTech Connect

The project uses an exothermic combustion synthesis reaction, termed self-propagating high-temperature synthesis (SHS), to produce high quality, reproducible nitride fuels and other ceramic type nuclear fuels (cercers and cermets, etc.) in conjunction with the fabrication of transmutation fuels. The major research objective of the project is determining the fundamental SHS processing parameters by first using manganese as a surrogate for americium to produce dense Zr-Mn-N ceramic compounds. These fundamental principles will then be transferred to the production of dense Zr-Am-N ceramic materials. A further research objective in the research program is generating fundamental SHS processing data to the synthesis of (i) Pu-Am-Zr-N and (ii) U-Pu-Am-N ceramic fuels. In this case, Ce will be used as the surrogate for Pu, Mn as the surrogate for Am, and depleted uranium as the surrogate for U. Once sufficient fundamental data has been determined for these surrogate systems, the information will be transferred to Idaho National Laboratory (INL) for synthesis of Zr-Am-N, Pu-Am-Zr-N and U-Pu-Am-N ceramic fuels. The high vapor pressures of americium (Am) and americium nitride (AmN) are cause for concern in producing nitride ceramic nuclear fuel that contains Am. Along with the problem of Am retention during the sintering phases of current processing methods, are additional concerns of producing a consistent product of desirable homogeneity, density and porosity. Similar difficulties have been experienced during the laboratory scale process development stage of producing metal alloys containing Am wherein compact powder sintering methods had to be abandoned. Therefore, there is an urgent need to develop a low-temperature or low–heat fuel fabrication process for the synthesis of Am-containing ceramic fuels. Self-propagating high temperature synthesis (SHS), also called combustion synthesis, offers such an alternative process for the synthesis of Am nitride fuels. Although SHS takes thermodynamic advantage of the high combustion temperatures of these exothermic SHS reactions to synthesize the required compounds, the very fast heating, reaction and cooling rates can kinetically generate extremely fast reaction rates and facilitate the retention of volatile species within the rapidly propagating SHS reaction front. The initial objective of the research program is to use Mn as the surrogate for Am to synthesize a reproducible, dense, high quality Zr-Mn-N ceramic compound. Having determined the fundamental SHS reaction parameters and optimized SHS processing steps using Mn as the surrogate for Am, the technology will be transferred to Idaho National Laboratory to successfully synthesize a high quality Zr-Am-N ceramic fuel.

John J. Moore, Marissa M. Reigel, Collin D. Donohoue

2009-04-30T23:59:59.000Z

296

Mechanisms of Oxide Scale Formation on Ferritic Interconnect Steel in Simulated Low and High pO2 Service Environments of Solid Oxide Fuel Cells  

Science Journals Connector (OSTI)

The Laves phase strengthened ferritic steel Crofer 22 H has recently been proposed as construction material for interconnects in solid oxide fuel cells (SOFCs). In the present study, the oxidation kinetics of ...

L. Niewolak; D. J. Young; H. Hattendorf; L. Singheiser…

2014-08-01T23:59:59.000Z

297

Ultra-high vacuum fabrication and electrical characterization of environmentally sensitive metal oxide semiconductor capacitors  

SciTech Connect

We describe an integrated, ultra-high vacuum system for metal oxide semiconductor (MOS) device fabrication and characterization. Such a system is advantageous for electrical property measurements of electronic devices consisting of environmentally sensitive materials especially as device dimensions approach the nanoscale. Without exposure to atomosphere, MOS capacitors were fabricated by evaporating gate metal on molecular-beam-epitaxy (MBE) grown dielectrics on 3 inch-diameter substrates through a shadow mask in a UHV electrode-patterning chamber. The finished device is transferred in vacuum to an in-situ, UHV electrical characterization probe station that was designed with standard UHV coaxial feedthroughs and UHV-compatible, Kapton-insulated coaxial cable. The probe station also includes a heated sample stage that allows for annealing and measurements in a controlled ambient. We obtained excellent agreement between air-ambient ex-situ and in-situ probe station measurements utilizing a capacitor standard compatible with UHV based on single crystal sapphire as the dielectric. The measurements show less than 0.3 % dispersion for frequencies from 20 Hz to 1 MHz. We have successfully measured MOS capacitors and are sensitive to a density of interface states of 1x1010 states cm-2 eV-1. These measurements also show 0.5 % dispersion for measurement frequencies from 20 Hz to 1 kHz and less than 0.1 % from 1 kHz to 1 MHz. The integrated system presented here is one where complex, MBE-grown MOS heterostructures can be synthesized and tested rapidly to elucidate new field-effect-device physics and functionality.

Billman, Curt [Oak Ridge National Laboratory (ORNL); Walker, Frederick Joseph [ORNL

2007-01-01T23:59:59.000Z

298

The Orientation Distributions of Lines, Surfaces, and Interfaces around Three-Phase Boundaries in Solid Oxide Fuel Cell Cathodes  

E-Print Network (OSTI)

in Solid Oxide Fuel Cell Cathodes Shen J. Dillon, Lam Helmick,§,¶ Herbert M. Miller,§ Lane Wilson in a multiphase ceramic material. I. Introduction THE active cathode regions of many solid oxide fuel cells (SOFCs of yttria-stabilized zirconia and lanthanum strontium manganese oxide, both before and after mild

Rohrer, Gregory S.

299

Neutron field characterisation at mixed oxide fuel plant  

Science Journals Connector (OSTI)

......plutonium oxide (PuO2) and 70 % depleted uranium oxide (UO2) are blended together...and typical field conditions. Health Phys. (1990) 58(6):691-704...Power Plants Quality Assurance, Health Care Radiation Dosage Radiation......

C. Passmore; M. Million; M. Kirr; J. Bartz; M. S. Akselrod; A. Devita; J. Berard

2012-06-01T23:59:59.000Z

300

NETL: News Release - Solid Oxide Fuel Cell Successfully Powers Truck Cab  

NLE Websites -- All DOE Office Websites (Extended Search)

9, 2009 9, 2009 Solid Oxide Fuel Cell Successfully Powers Truck Cab and Sleeper in DOE-Sponsored Test DOE, Delphi, Peterbilt Join to Test Auxiliary Power Unit for Commercial Trucks Washington, DC -In a test sponsored by the U.S. Department of Energy (DOE), a Delphi auxiliary power unit employing a solid oxide fuel cell (SOFC) successfully operated the electrical system and air conditioning of a Peterbilt Model 386 truck under conditions simulating idling conditions for 10 hours. The device provides an alternative to running a truck's main diesel engine, or using a truck's batteries, to power auxiliary electrical loads during rest periods, thereby lowering emissions, reducing noise, and saving fuel. Solid Oxide Fuel Cell Successfully Powers Truck Cab and Sleeper in DOE-Sponsored Test

Note: This page contains sample records for the topic "oxide fuel fabrication" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


301

SAMARIUM-BASED INTERMEDIATE TEMPERATURE SOLID OXIDE FUEL CELLS.  

E-Print Network (OSTI)

??The development of electrochemical converters (i.e. fuel cells) has attracted research interest during the last decades due to an increasing concern on the depletion of… (more)

Guzman Montanez, Felipe

2005-01-01T23:59:59.000Z

302

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

Science Journals Connector (OSTI)

Abstract 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.

Phanicha Tippawan; Amornchai Arpornwichanop

2014-01-01T23:59:59.000Z

303

MATERIAL AND PROCESS DEVELOPMENT LEADING TO ECONOMICAL HIGH-PERFORMANCE THIN-FILM SOLID OXIDE FUEL CELLS  

SciTech Connect

This document summarizes the technical progress from September 2002 to March 2003 for the program, Material and Process Development Leading to Economical High-Performance Thin-Film Solid Oxide Fuel Cells, contract number DE-AC26-00NT40711. The causes have been identified for the unstable open circuit voltage (OCV) and low performance exhibited by the anode-supported lanthanum gallate based cells from the earlier development. Promising results have been obtained in the area of synthesis of electrolyte and cathode powders, which showed excellent sintering and densification at low temperatures. The fabrication of cells using tapecalendering process for anode-supported thin lanthanum gallate electrolyte cells and their performance optimization is in progress.

Jie Guan; Atul Verma; Nguyen Minh

2003-04-01T23:59:59.000Z

304

Fuel Preprocessor (FPP) for a Solid Oxide Fuel Cell Auxiliary Power Unit  

SciTech Connect

Auxiliary Power Units (APUs), driven by truck engines, consume over 800 million gallon of diesel fuel while idling. Use of separate SOFC based APUs are an excellent choice to reduce the cost and pollution associated with producing auxiliary power. However, diesel fuel is a challenging fuel to use in fuel cell systems because it has heavy hydrocarbons that can transform into carbon deposits and gums that can block passages and deactivate fuel reformer and fuel cell reactor elements. The work reported herein addresses the challenges associated with the diesel fuel sulfur and carbon producing contaminants in a Fuel Preprocessor (FPP). FPP processes the diesel fuel onboard and ahead of the reformer to reduce its carbon deposition tendency and its sulfur content, thus producing a fuel suitable for SOFC APU systems. The goal of this DOE supported Invention and Innovation program was to design, develop and test a prototype Fuel Preprocessor (FPP) that efficiently and safely converts the diesel fuel into a clean fuel suitable for a SOFC APU system. The goals were achieved. A 5 kWe FPP was designed, developed and tested. It was demonstrated that FPP removes over 80% of the fuel sulfur and over 90% of its carbon residues and it was demonstrated that FPP performance exceeds the original project goals.

M. Namazian, S. Sethuraman and G. Venkataraman

2004-12-31T23:59:59.000Z

305

Characterization of Solid Oxide Fuel Cell Sealant Material G18 by Microindentation Alexandra Woldman, Cornell University, 2009 SURF Fellow  

E-Print Network (OSTI)

Milhans Introduction Solid oxide fuel cells (SOFC) require a hermetic seal between the fuel and air side of the electrodes in order to function properly. The cracking or leaking of an SOFC seal is the end of the useful

Li, Mo

306

Molybdenum Dioxide As A Solid Oxide Fuel Cell Anodic Catalyst  

E-Print Network (OSTI)

-Marins, Sean Parris, and Caleb Ellefson Introduction to Multiscale Engineering School of Mechanical and Materials Engineering This work was supported by the National Science Foundation's REU program Introduction in fuels such as biodiesel or jet fuel, SOFC anodes are poisoned, rendering them useless. Research

Collins, Gary S.

307

Electrochemical Performance and Stability of the Cathode for Solid Oxide Fuel Cells IV. On the Ohmic loss in anode supported button cells with LSM or LSCF cathodes  

SciTech Connect

Anode-supported solid oxide fuel cells (SOFC) with a variety of YSZ electrolyte thicknesses were fabricated by tape casting and lamination. The preparation of the YSZ electrolyte tapes with various thicknesses was accomplished by using doctor blades with different gaps between the precision machined, polished blade and the casting surface. The green tape was cut into discs, sintered at 1385°C for 2 h, and subsequently creep-flattened at 1350°C for 2 h. Either LSCF with an SDC interlayer or LSM+YSZ composite was used as the cathode material for the fuel cells. The ohmic resistances of these anode-supported fuel cells were characterized by electrochemical impedance spectroscopy at temperatures from 500°C to 750°C. A linear relationship was found between the ohmic resistance of the fuel cell and the YSZ electrolyte thickness at all the measuring temperatures for both LSCF and LSM+YSZ cathode fuel cells. The ionic conductivities of the YSZ electrolyte, derived for the fuel cells with LSM+YSZ or LSCF cathodes, were independent of the cathode material and cell configuration. The ionic conductivities of the YSZ electrolyte was slightly lower than that of the bulk material, possibly due to Ni-doping into the electrolyte. The fuel cell with a SDC interlayer and LSCF cathode showed larger intercept resistance than the fuel cell with LSM+YSZ cathode, which was possibly due to the imperfect contact between the SDC interlayer and the YSZ electrolyte and the migration of Zr into the SDC interlayer to form an insulating solid solution during cell fabrication. Calculations of the contribution of the YSZ electrolyte to the total ohmic resistance showed that YSZ was still a satisfactory electrolyte at temperatures above 650°C. Explorations should be directed to reduce the intercept resistance to achieve significant improvement in cell performance.

Lu, Zigui; Zhou, Xiao Dong; Templeton, Jared W.; Stevenson, Jeffry W.

2010-05-08T23:59:59.000Z

308

Grain-size effects in nanoscaled electrolyte and cathode thin films for solid oxide fuel cells (SOFC).  

E-Print Network (OSTI)

??Due to their high energy conversion efficiencies and low emissions, Solid Oxide Fuel Cells (SOFCs) show promise as a replacement for combustion-based electrical generators at… (more)

Peters, Christoph

2009-01-01T23:59:59.000Z

309

Fuel Processing for Portable Power Fuel Cell Systems: Preferential Oxidation in  

E-Print Network (OSTI)

Reformer Water-Gas Shift CO Elimination Fuel Processor Fuel Cell Hydrocarbon Fuel Electrical Power H2-rich Microfabrication Kinetic Simulation Fluidic Modeling 222 1 COOCO + #12;Approach Microreactor Design Development (Bednarova) Mechanism Development (Bednarova) Kinetic Model w/ CHEMKIN (Ho) Kinetic Model w

Besser, Ronald S.

310

Journal of Power Sources 153 (2006) 6875 Numerical study of a flat-tube high power density solid oxide fuel cell  

E-Print Network (OSTI)

power density (HPD) solid oxide fuel cell (SOFC) is a geometry based on a tubular type SOFC: Flat-tube; High power density (HPD); Solid oxide fuel cell (SOFC); Simulation; Performance; Optimization 1. Introduction A solid oxide fuel cell (SOFC), like any other fuel cell, produces electrical

311

Unveiling Structure-Property Relationships in Sr2Fe1.5Mo0.5O6-, an Electrode Material for Symmetric Solid Oxide Fuel Cells  

E-Print Network (OSTI)

Solid Oxide Fuel Cells Ana B. Munoz-García, Daniel E. Bugaris, Michele Pavone,,§ Jason P. Hodges, Ashfia oxide fuel cell electrode material Sr2Fe1.5Mo0.5O6- (SFMO). Rietveld refinement of powder neutron oxide fuel cells (SOFCs) can convert a wide variety of fuels with simpler and cheaper designs than those

Carter, Emily A.

312

High Thermal Conductivity UO2-BeO Nulcear Fuel: Neutronic Performance Assessments and Overview of Fabrication  

E-Print Network (OSTI)

for the continuous (a) and dispersed (b) types [16]. 2.3 Silicon Carbide as a High Conductivity Additive Solomon et al. explored the feasibility of increasing the thermal conductivity of oxide fuels by the addition of a second, higher thermal conductivity solid... methodology used to restrict the CO or SiO gases. All processing, therefore, must take place below this temperature. Because of ! "# Table 2.3. Samples used in the thermal conductivity measurements $%&'()&*! $(+!%,-.&/! 0...

Naramore, Michael J

2010-08-03T23:59:59.000Z

313

E-Print Network 3.0 - atr fuel fabrication Sample Search Results  

NLE Websites -- All DOE Office Websites (Extended Search)

Collection: Environmental Management and Restoration Technologies 3 2003 Hydrogen and Fuel Cells Merit Review Meeting May 19-22, 2003, Berkeley, CA Summary: Argonne...

314

E-Print Network 3.0 - ag fuel fabrication Sample Search Results  

NLE Websites -- All DOE Office Websites (Extended Search)

in this ... Source: DOE Office of Energy Efficiency and Renewable Energy, Hydrogen, Fuel Cells and Infrastructure Technologies Program Collection: Energy Storage, Conversion...

315

INVESTIGATION OF NOVEL ALLOY TiC-Ni-Ni3Al FOR SOLID OXIDE FUEL CELL INTERCONNECT APPLICATIONS  

SciTech Connect

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.

Rasit Koc; Geoffrey Swift; Hua Xie

2005-01-25T23:59:59.000Z

316

Fuel instability studies; Liquid phase oxidation of tetrahydrothiophene by tert-butyl hydroperoxide  

SciTech Connect

The reactions that lead to fuel instability are the subject of conflicting reports in the literature. Confusion results from the difficulty in relating differences in fuel composition, temperature, surface effects and dissolved oxygen content that comprise the multitude of reported studies. Model studies offer a means by chic the mechanism of an individual reaction can be related to a simple system and then extended to the more complex fuel media. This paper reports a model oxidation study of a species, t-butyl hydroperoxide under mild reaction conditions, 120{degrees}C, in a tetradecane model fuel. The major oxidation product was tetrahydrothiophene sulfoxide from the sulfide and t-butanol from the hydroperoxide. The complete suite of products is reported.

Mushrush, G.W.; Pellenbarg, R.E.; Hazlett, R.N.; Morris, R.E.; Hardy, D.R. (Fuels Section, Code 6180, Naval Research Lab., Washington, DC (US))

1991-01-01T23:59:59.000Z

317

Modified cermet fuel electrodes for solid oxide electrochemical cells  

DOE Patents (OSTI)

An exterior porous electrode (10), bonded to a solid oxygen ion conducting electrolyte (13) which is in contact with an interior electrode (14), contains coarse metal particles (12) of nickel and/or cobalt, having diameters from 3 micrometers to 35 micrometers, where the coarse particles are coated with a separate, porous, multiphase layer (17) containing fine metal particles of nickel and/or cobalt (18), having diameters from 0.05 micrometers to 1.75 micrometers and conductive oxide (19) selected from cerium oxide, doped cerium oxide, strontium titanate, doped strontium titanate and mixtures thereof.

Ruka, Roswell J. (Churchill Boro, PA); Spengler, Charles J. (Murrysville, PA)

1991-01-01T23:59:59.000Z

318

Solid Oxide Fuel Cell Balance of Plant and Stack Component Integration  

NLE Websites -- All DOE Office Websites (Extended Search)

Oxide Fuel Cell Balance of Plant Oxide Fuel Cell Balance of Plant & Stack Component Integration Norman Bessette Acumentrics Corporation March 16, 2010 Acumentrics Corporation *Based in Westwood, Mass. *~40,000 sq. ft facility *Profitable * Critical disciplines in-house El t i l E i i Strategic Partners Electrical Engineering Mechanical Engineering Chemical Engineering Thermal Modeling Ceramics Processing Manufacturing Sales & Marketing Automation Finance Scalable, Ruggedized Power - Combat Proven Take Almost Any Generator Plug into Clean Power Provided by Acumentrics RUPS And Be Ready For Continuous Communications

319

LMFBR fuel-design environment for endurance testing, primarily of oxide fuel elements with local faults  

SciTech Connect

The US Department of Energy LMFBR Lines-of-Assurance are briefly stated and local faults are given perspective with an historical review and definition to help define the constraints of LMFBR fuel-element designs. Local-fault-propagation (fuel-element failure-propagation and blockage propagation) perceptions are reviewed. Fuel pin designs and major LMFBR parameters affecting pin performance are summarized. The interpretation of failed-fuel data is aided by a discussion of the effects of nonprototypicalities. The fuel-pin endurance expected in the US, USSR, France, UK, Japan, and West Germany is outlined. Finally, fuel-failure detection and location by delayed-neutron and gaseous-fission-product monitors are briefly discussed to better realize the operational limits.

Warinner, D.K.

1980-01-01T23:59:59.000Z

320

Pyroprocessing oxide spent nuclear fuels for efficient disposal  

SciTech Connect

Pyrochemical processing as a means for conditioning spent nuclear fuels for disposal offers significant advantages over the direct disposal option. The advantages include reduction in high-level waste volume; conversion of most of the high-level waste to a low-level waste in which nearly all the transuranics (TRU) have been removed; and incorporation of the TRUs into a stable, highly radioactive waste form suitable for interim storage, ultimate destruction, or repository disposal. The lithium process has been under development at Argonne National Laboratory for use in pyrochemical conditioning of spent fuel for disposal. All of the process steps have been demonstrated in small-scale (0.5-kg simulated spent fuel) experiments. Engineering-scale (20-kg simulated spent fuel) demonstration of the process is underway, and small-scale experiments have been conducted with actual spent fuel from a light water reactor (LWR). The lithium process is simple, operates at relatively low temperatures, and can achieve high decontamination factors for the TRU elements. Ordinary materials, such as carbon steel, can be used for process containment.

McPheeters, C.C.; Pierce, R.D.; Mulcahey, T.P. [Argonne National Lab., IL (United States). Chemical Technology Div.

1994-12-31T23:59:59.000Z

Note: This page contains sample records for the topic "oxide fuel fabrication" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


321

Durability Prediction of Solid Oxide Fuel Cell Anode Material under Thermo-Mechanical and Fuel Gas Contaminants Effects  

SciTech Connect

Solid Oxide Fuel Cells (SOFCs) operate under harsh environments, which cause deterioration of anode material properties and service life. In addition to electrochemical performance, structural integrity of the SOFC anode is essential for successful long-term operation. The SOFC anode is subjected to stresses at high temperature, thermal/redox cycles, and fuel gas contaminants effects during long-term operation. These mechanisms can alter the anode microstructure and affect its electrochemical and structural properties. In this research, anode material degradation mechanisms are briefly reviewed and an anode material durability model is developed and implemented in finite element analysis. The model takes into account thermo-mechanical and fuel gas contaminants degradation mechanisms for prediction of long-term structural integrity of the SOFC anode. The proposed model is validated experimentally using a NexTech ProbostatTM SOFC button cell test apparatus integrated with a Sagnac optical setup for simultaneously measuring electrochemical performance and in-situ anode surface deformation.

Iqbal, Gulfam; Guo, Hua; Kang , Bruce S.; Marina, Olga A.

2011-01-10T23:59:59.000Z

322

Electro-catalytic oxidation device for removing carbon from a fuel reformate  

DOE Patents (OSTI)

An electro-catalytic oxidation device (ECOD) for the removal of contaminates, preferably carbonaceous materials, from an influent comprising an ECOD anode, an ECOD cathode, and an ECOD electrolyte. The ECOD anode is at a temperature whereby the contaminate collects on the surface of the ECOD anode as a buildup. The ECOD anode is electrically connected to the ECOD cathode, which consumes the buildup producing electricity and carbon dioxide. The ECOD anode is porous and chemically active to the electro-catalytic oxidation of the contaminate. The ECOD cathode is exposed to oxygen, and made of a material which promotes the electro-chemical reduction of oxygen to oxidized ions. The ECOD electrolyte is non-permeable to gas, electrically insulating and a conductor to oxidized. The ECOD anode is connected to the fuel reformer and the fuel cell. The ECOD electrolyte is between and in ionic contact with the ECOD anode and the ECOD cathode.

Liu, Di-Jia (Naperville, IL)

2010-02-23T23:59:59.000Z

323

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

E-Print Network (OSTI)

??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… (more)

Lin, Jiefeng

2013-01-01T23:59:59.000Z

324

Corrosion and Protection of Metallic Interconnects in Solid Oxide Fuel Cells  

SciTech Connect

Energy security and increased concern over environmental protection have spurred a dramatic world-wide growth in research and development of fuel cells, which electrochemically convert incoming fuel into electricity with no or low pollution. Fuel cell technology has become increasingly attractive to a number of sectors, including utility, automotive, and defense industries. Among the various types of fuel cells, solid oxide fuel cells (SOFCs) operate at high temperature (typically 650-1,000 C) and have advantages in terms of high conversion efficiency and the flexibility of using hydrocarbon fuels, in addition to hydrogen. The high temperature operation, however, can lead to increased mass transport and interactions between the surrounding environment and components that are required to be stable during a lifetime of thousands of hours and up to hundreds of thermal cycles. For stacks with relatively low operating temperatures (<800 C), the interconnects that are used to electrically connect a number of cells in series are typically made from cost-effective metals or alloys. The metallic interconnects must demonstrate excellent stability in a very challenging environment during SOFC operation, as they are simultaneously exposed to both an oxidizing (air) environment on the cathode side and a reducing environment (hydrogen or a reformed hydrocarbon fuel) on the anode side. Other challenges include the fact that water vapor is likely to be present in both of these environments, and the fuel is likely to contain impurities, such as sulfides. Since the fuel is usually a reformed hydrocarbon fuel, such as natural gas, coal gas, biogas, gasoline, etc., the interconnect is exposed to a wet carbonaceous environment at the anode side. Finally, the interconnect must be stable towards any adjacent components, such as electrodes, seals and electrical contact materials, with which it is in physical contact.

Yang, Z Gary; Stevenson, Jeffry W.; Singh, Prabhakar

2007-12-09T23:59:59.000Z

325

Novel Sulfur-Tolerant Anodes for Solid Oxide Fuel Cells  

SciTech Connect

One of the unique advantages of SOFCs over other types of fuel cells is the potential for direct utilization of hydrocarbon fuels (it may involve internal reforming). Unfortunately, most hydrocarbon fuels contain sulfur, which would dramatically degrade SOFC performance at parts-per-million (ppm) levels. Low concentration of sulfur (ppm or below) is difficult to remove efficiently and cost-effectively. Therefore, knowing the exact poisoning process for state-of-the-art anode-supported SOFCs with Ni-YSZ cermet anodes, understanding the detailed anode poisoning mechanism, and developing new sulfur-tolerant anodes are essential to the promotion of SOFCs that run on hydrocarbon fuels. The effect of cell operating conditions (including temperature, H{sub 2}S concentration, cell voltage/current density, etc.) on sulfur poisoning and recovery of nickel-based anode in SOFCs was investigated. It was found that sulfur poisoning is more severe at lower temperature, higher H{sub 2}S concentration or lower cell current density (higher cell voltage). In-situ Raman spectroscopy identified the nickel sulfide formation process on the surface of a Ni-YSZ electrode and the corresponding morphology change as the sample was cooled in H{sub 2}S-containing fuel. Quantum chemical calculations predicted a new S-Ni phase diagram with a region of sulfur adsorption on Ni surfaces, corresponding to sulfur poisoning of Ni-YSZ anodes under typical SOFC operating conditions. Further, quantum chemical calculations were used to predict the adsorption energy and bond length for sulfur and hydrogen atoms on various metal surfaces. Surface modification of Ni-YSZ anode by thin Nb{sub 2}O{sub 5} coating was utilized to enhance the sulfur tolerance. A multi-cell testing system was designed and constructed which is capable of simultaneously performing electrochemical tests of 12 button cells in fuels with four different concentrations of H{sub 2}S. Through systematical study of state-of-the-art anode-supported SOFC button cells, it is seen that the long-term sulfur poisoning behavior of those cells indicate that there might be a second-stage slower degradation due to sulfur poisoning, which would last for a thousand hour or even longer. However, when using G-18 sealant from PNNL, the 2nd stage poisoning was effectively prohibited.

Lei Yang; Meilin Liu

2008-12-31T23:59:59.000Z

326

Solid oxide fuel cell with transitioned cross-section for improved anode gas management at the open end  

DOE Patents (OSTI)

A solid oxide fuel cell (400) is made having a tubular, elongated, hollow, active section (445) which has a cross-section containing an air electrode (452) a fuel electrode (454) and solid oxide electrolyte (456) between them, where the fuel cell transitions into at least one inactive section (460) with a flattened parallel sided cross-section (462, 468) each cross-section having channels (472, 474, 476) in them which smoothly communicate with each other at an interface section (458).

Zafred, Paolo R. (Murrysville, PA); Draper, Robert (Pittsburgh, PA)

2012-01-17T23:59:59.000Z

327

High Temperature Solid Oxide Fuel Cell Generator Development  

SciTech Connect

Work performed during the period February 21, 2006 through August 21, 2006 is summarized herein. During this period, efforts were focused on 5 kWe bundle testing, development of on-cell reformation, the conceptual design of an advanced module, and the development of a manufacturing roadmap for cells and bundles. A 5 kWe SOFC system was built and delivered to the Pennsylvania State University; fabrication of a second 5 kWe SOFC for delivery to Montana State University was initiated. Cell testing and microstructural analysis in support of these efforts was also conducted.

Joseph F. Pierre

2006-08-21T23:59:59.000Z

328

EMISSIONS OF NITROUS OXIDE AND METHANE FROM CONVENTIONAL AND ALTERNATIVE FUEL MOTOR VEHICLES  

E-Print Network (OSTI)

-produced electricity for battery electric vehicles. Already, vehicles powered by compressed natural gas, propane. LIPMAN AND MARK A. DELUCCHI example, promising strategies for powering motor vehicles with reduced GHGEMISSIONS OF NITROUS OXIDE AND METHANE FROM CONVENTIONAL AND ALTERNATIVE FUEL MOTOR VEHICLES

Kammen, Daniel M.

329

Influence of NaCl on cathode performance of solid oxide fuel cells  

Science Journals Connector (OSTI)

Degradation induced by sodium chloride in air was...0.8Sr0.2)0.98MnO3(LSM) and La0.6Sr0.4Co0.2Fe0.8O3(LSCF) cathodes in solid oxide fuel cells(SOFC). Cell performance was measured by volatilizing NaCl to...2...fo...

Run-ru Liu; De-jun Wang; Jing Leng

2013-08-01T23:59:59.000Z

330

Solid oxide fuel cell systems with hot zones having improved reactant distribution  

DOE Patents (OSTI)

A Solid Oxide Fuel Cell (SOFC) system having a hot zone with a center cathode air feed tube for improved reactant distribution, a CPOX reactor attached at the anode feed end of the hot zone with a tail gas combustor at the opposing end for more uniform heat distribution, and a counter-flow heat exchanger for efficient heat retention.

Poshusta, Joseph C.; Booten, Charles W.; Martin, Jerry L.

2012-11-06T23:59:59.000Z

331

Application of Atomic Layer Deposition of Platinum to Solid Oxide Fuel Cells  

Science Journals Connector (OSTI)

Application of Atomic Layer Deposition of Platinum to Solid Oxide Fuel Cells ... (4, 5, 8-10) Therefore, the electrode material requires particular attention in the development and optimization of low-temperature SOFCs. ... Enormous Plasmonic Enhancement and Suppressed Quenching of Luminescence from Nanoscale ZnO Films by Uniformly Dispersed Atomic-Layer-Deposited Platinum with Optimized Spacer Thickness ...

Xirong Jiang; Hong Huang; Friedrich B. Prinz; Stacey F. Bent

2008-05-23T23:59:59.000Z

332

Assessment of the Distributed Generation Market Potential for Solid Oxide Fuel Cells  

NLE Websites -- All DOE Office Websites (Extended Search)

the Distributed the Distributed Generation Market Potential for Solid Oxide Fuel Cells September 29, 2013 DOE/NETL- 342/093013 NETL Contact: Katrina Krulla Analysis Team: Arun Iyengar, Dale Keairns, Dick Newby Contributors: Walter Shelton, Travish Shulltz, Shailesh Vora OFFICE OF FOSSIL ENERGY Table of Contents Executive Summary .........................................................................................................................1 1 Introduction ...................................................................................................................................2 2 DG Market Opportunity ................................................................................................................3 3 SOFC Technology Development Plan ..........................................................................................6

333

Fabrication of Metal/Oxide Nanostructures by Anodization Processes for Biosensor, Drug Delivery and Supercapacitor Applications  

E-Print Network (OSTI)

applications of micro/nano structures; (2) novel processes to innovate anodic aluminum oxide nanotube template; (3) the supercapacitor applications of anodic titanium oxide. First, the extremely high surface area AAO coated microneedle and microneedle array...

Chen, Po-Chun

2014-01-13T23:59:59.000Z

334

Activity and structure of perovskites as diesel reforming catalysts for solid oxide fuel cells.  

SciTech Connect

Recent progress in developing perovskite materials as more cost-effective catalysts in autothermal reforming (ATR) of diesel fuel to hydrogen-rich reformate for solid oxide fuel cell (SOFC) application is reported. Perovskite-type metal oxides with B sites partially exchanged by ruthenium were prepared and evaluated under ATR reaction conditions. The hydrogen yield, reforming efficiency, and CO{sub x} selectivity of these catalysts were investigated using diesel surrogate fuel with 50 ppm sulfur. The catalyst performances have approached or exceeded a benchmark, high-cost rhodium-based material. In parallel with the reactivity study, we also investigated the physical properties of B-site doped perovskites and their impact on the reforming performance using various characterization techniques such as BET, X-ray powder diffraction, temperature programmable reduction, scanning electron microscopy, and synchrotron X-ray absorption spectroscopy. We found that ruthenium is highly dispersed into perovskite lattice and its redox behavior is directly associated with reforming activity.

Liu, D.-J.; Krumpelt, M.; Chemical Engineering

2005-01-01T23:59:59.000Z

335

Oxidation and stabilization of hydrocarbon fuels in contact with rock salt  

SciTech Connect

Underground storage is the most ecologically clean and economical method for extended storage of natural gas, crude oil, and petroleum products. Such storage reservoirs are created in stable rock (granites, gneisses, limestone, etc.), rock salt deposits, clays, abandoned mines, and permafrost formations. In this investigation of the influence of rock salt deposits on the oxidation of hydrocarbons (summer-grade straight-run diesel fuel L and automotive gasoline A-76 [unleaded, low-octane]), the authors carried out a kinetic study of hydroperoxide accumulation during the oxidation of these fuels after contact with a saturated solution of rock salt (brine). The experiments were performed in a bubbler-type unit with various ratios of brine to fuel.

Klinaeva, E.V.; Golubeva, I.A.; Tolstykh, L.I. [and others

1995-11-01T23:59:59.000Z

336

Solid Oxide Fuel Cell Development at Topsoe Fuel Cell A/S and Ris National Laboratory  

E-Print Network (OSTI)

catalyst. The range of fuels has further been extended to include ethanol and coal syn-gas by development of a new coke resistant catalyst suitable for future SOFC technology. CELL DEVELOPMENT AND PRODUCTION

337

Americium separation from nuclear fuel dissolution using higher oxidation states.  

SciTech Connect

Much of the complexity in current AFCI proposals is driven by the need to separate the minor actinides from the lanthanides. Partitioning and recycling Am, but not Cm, would allow for significant simplification because Am has redox chemistry that may be exploited while Cm does not. Here, we have explored methods based on higher oxidation states of Am (AmV and AmVI) to partition Am from the lanthanides. In a separate but related approach we have also initiated an investigation of the utility of TRUEX Am extraction from thiocyanate solution. The stripping of loaded TRUEX by Am oxidation or SCN- has not yet proved successful; however, the partitioning of inextractable AmV by TRUEX shows promise.

Bruce J. Mincher

2009-09-01T23:59:59.000Z

338

Journal of Power Sources 140 (2005) 331339 Numerical study of a flat-tube high power density solid oxide fuel cell  

E-Print Network (OSTI)

) solid oxide fuel cell (SOFC) is a new design developed by Siemens Westinghouse, based on their formerly.V. All rights reserved. Keywords: Flat-tube; High power density; Solid oxide fuel cell; Simulation; Heat oxide fuel cell Part I. Heat/mass transfer and fluid flow Yixin Lu1, Laura Schaefer, Peiwen Li2

339

ReaxFF Reactive Force Field for Solid Oxide Fuel Cell Systems with Application to Oxygen Ion Transport in Yttria-Stabilized Zirconia  

E-Print Network (OSTI)

ReaxFF Reactive Force Field for Solid Oxide Fuel Cell Systems with Application to Oxygen Ion through yttria-stabilized zirconia (YSZ) solid oxide fuel cell (SOFC) membranes. All parameters for Reax temperature, leading to applications as oxygen sensors and as membranes for high temperature solid oxide fuel

Goddard III, William A.

340

Transient thermal behaviour of a solid oxide fuel cell Moussa Chnani, Marie-Ccile Pra, Raynal Glises, Jean Marie Kauffmann and  

E-Print Network (OSTI)

Transient thermal behaviour of a solid oxide fuel cell Moussa Chnani, Marie-CĂ©cile PĂ©ra, Raynal provided by HTceramix. Keywords: Solid oxide fuel cell; Transient thermal modelling; Fluidic and Electrochemical modelling. 1- Introduction The solid oxide fuel cell (SOFC) is a promising technology

Paris-Sud XI, Université de

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341

Mechanisms Underpinning Degradation of Protective Oxides and Thermal Barrier Coatings in High Hydrogen Content (HHC) - Fueled Turbines  

SciTech Connect

The overarching goal of this research program has been to evaluate the potential impacts of coal-derived syngas and high-hydrogen content fuels on the degradation of turbine hot-section components through attack of protective oxides and thermal barrier coatings. The primary focus of this research program has been to explore mechanisms underpinning the observed degradation processes, and connections to the combustion environments and characteristic non-combustible constituents. Based on the mechanistic understanding of how these emerging fuel streams affect materials degradation, the ultimate goal of the program is to advance the goals of the Advanced Turbine Program by developing materials design protocols leading to turbine hot-section components with improved resistance to service lifetime degradation under advanced fuels exposures. This research program has been focused on studying how: (1) differing combustion environments – relative to traditional natural gas fired systems – affect both the growth rate of thermally grown oxide (TGO) layers and the stability of these oxides and of protective thermal barrier coatings (TBCs); and (2) how low levels of fuel impurities and characteristic non-combustibles interact with surface oxides, for instance through the development of molten deposits that lead to hot corrosion of protective TBC coatings. The overall program has been comprised of six inter-related themes, each comprising a research thrust over the program period, including: (i) evaluating the role of syngas and high hydrogen content (HHC) combustion environments in modifying component surface temperatures, heat transfer to the TBC coatings, and thermal gradients within these coatings; (ii) understanding the instability of TBC coatings in the syngas and high hydrogen environment with regards to decomposition, phase changes and sintering; (iii) characterizing ash deposition, molten phase development and infiltration, and associated corrosive/thermo-chemical attack mechanisms; (iv) developing a mechanics-based analysis of the driving forces for crack growth and delamination, based on molten phase infiltration, misfit upon cooling, and loss of compliance; (v) understanding changes in TGO growth mechanisms associated with these emerging combustion product streams; and (vi) identifying degradation resistant alternative materials (including new compositions or bi-layer concepts) for use in mitigating the observed degradation modes. To address the materials stability concerns, this program integrated research thrusts aimed at: (1) Conducting tests in simulated syngas and HHC environments to evaluate materials evolution and degradation mechanisms; assessing thermally grown oxide development unique to HHC environmental exposures; carrying out high-resolution imaging and microanalysis to elucidate the evolution of surface deposits (molten phase formation and infiltration); exploring thermo-chemical instabilities; assessing thermo-mechanical drivers and thermal gradient effects on degradation; and quantitatively measuring stress evolution due to enhanced sintering and thermo-chemical instabilities induced in the coating. (2) Executing experiments to study the melting and infiltration of simulated ash deposits, and identifying reaction products and evolving phases associated with molten phase corrosion mechanisms; utilizing thermal spray techniques to fabricate test coupons with controlled microstructures to study mechanisms of instability and degradation; facilitating thermal gradient testing; and developing new materials systems for laboratory testing; (3) Correlating information on the resulting combustion environments to properly assess materials exposure conditions and guide the development of lab-scale simulations of material exposures; specification of representative syngas and high-hydrogen fuels with realistic levels of impurities and contaminants, to explore differences in heat transfer, surface degradation, and deposit formation; and facilitating combustion rig testing of materials test coupons.

Mumm, Daniel

2013-08-31T23:59:59.000Z

342

A Low-Cost Soft-Switched DC/DC Converter for Solid-Oxide Fuel Cells  

SciTech Connect

A highly efficient DC to DC converter has been developed for low-voltage high-current solid oxide fuel cells. The newly developed 'V6' converter resembles what has been done in internal combustion engine that split into multiple cylinders to increase the output capacity without having to increase individual cell size and to smooth out the torque with interleaving operation. The development was started with topology overview to ensure that all the DC to DC converter circuits were included in the study. Efficiency models for different circuit topologies were established, and computer simulations were performed to determine the best candidate converter circuit. Through design optimization including topology selection, device selection, magnetic component design, thermal design, and digital controller design, a bench prototype rated 5-kW, with 20 to 50V input and 200/400V output was fabricated and tested. Efficiency goal of 97% was proven achievable through hardware experiment. This DC to DC converter was then modified in the later stage to converter 35 to 63 V input and 13.8 V output for automotive charging applications. The complete prototype was tested at Delphi with their solid oxide fuel cell test stand to verify the performance of the modified DC to DC converter. The output was tested up to 3-kW level, and the efficiency exceeded 97.5%. Multiple-phase interleaving operation design was proved to be reliable and ripple free at the output, which is desirable for the battery charging. Overall this is a very successful collaboration project between the SECA Core Technology Team and Industrial Team.

Jason Lai

2009-03-03T23:59:59.000Z

343

Effect of Coal Contaminants on Solid Oxide Fuel System Performance and Service Life  

SciTech Connect

The U.S. Department of Energy's SECA program envisions the development of high-efficiency, low-emission, CO{sub 2} sequestration-ready, and fuel-flexible technology to produce electricity from fossil fuels. One such technology is the integrated gasification-solid oxide fuel cell (SOFC) that produces electricity from the gas stream of a coal gasifier. SOFCs have high fuel-to-electricity conversion efficiency, environmental compatibility (low NO{sub x} production), and modularity. Naturally occurring coal has many impurities and some of these impurities end in the fuel gas stream either as a vapor or in the form of fine particulate matter. Establishing the tolerance limits of SOFCs for contaminants in the coal-derived gas will allow proper design of the fuel feed system that will not catastrophically damage the SOFC or allow long-term cumulative degradation. The anodes of Ni-cermet-based SOFCs are vulnerable to degradation in the presence of contaminants that are expected to be present in a coal-derived fuel gas stream. Whereas the effects of some contaminants such as H{sub 2}S, NH{sub 3} and HCl have been studied, the effects of other contaminants such as As, P, and Hg have not been ascertained. The primary objective of this study was to determine the sensitivity of the performance of solid oxide fuel cells to trace level contaminants present in a coal-derived gas stream in the temperature range 700 to 900 C. The results were used to assess catastrophic damage risk and long-term cumulative effects of the trace contaminants on the lifetime expectancy of SOFC systems fed with coal-derived gas streams.

Gopala Krishnan; P. Jayaweera; J. Bao; J. Perez; K. H. Lau; M. Hornbostel; A. Sanjurjo; J. R. Albritton; R. P. Gupta

2008-09-30T23:59:59.000Z

344

The behaviour of transuranic mixed oxide fuel in a Candu-900 reactor  

SciTech Connect

The production of transuranic actinide fuels for use in current thermal reactors provides a useful intermediary step in closing the nuclear fuel cycle. Extraction of actinides reduces the longevity, radiation and heat loads of spent material. The burning of transuranic fuels in current reactors for a limited amount of cycles reduces the infrastructure demand for fast reactors and provides an effective synergy that can result in a reduction of as much as 95% of spent fuel waste while reducing the fast reactor infrastructure needed by a factor of almost 13.5 [1]. This paper examines the features of actinide mixed oxide fuel, TRUMOX, in a CANDU{sup R}* nuclear reactor. The actinide concentrations used were based on extraction from 30 year cooled spent fuel and mixed with natural uranium in 3.1 wt% actinide MOX fuel. Full lattice cell modeling was performed using the WIMS-AECL code, super-cell calculations were analyzed in DRAGON and full core analysis was executed in the RFSP 2-group diffusion code. A time-average full core model was produced and analyzed for reactor coefficients, reactivity device worth and online fuelling impacts. The standard CANDU operational limits were maintained throughout operations. The TRUMOX fuel design achieved a burnup of 27.36 MWd/kg HE. A full TRUMOX fuelled CANDU was shown to operate within acceptable limits and provided a viable intermediary step for burning actinides. The recycling, reprocessing and reuse of spent fuels produces a much more sustainable and efficient nuclear fuel cycle. (authors)

Morreale, A. C.; Ball, M. R.; Novog, D. R.; Luxat, J. C. [Dept. of Engineering Physics, McMaster Univ., 1280 Main St. W, Hamilton, ON (Canada)

2012-07-01T23:59:59.000Z

345

Composite Cathode for High-Power Density Solid Oxide Fuel Cells  

SciTech Connect

Reduction of solid oxide fuel cell (SOFC) operating temperature will play a key role in reducing the stack cost by allowing the use of low-cost metallic interconnects and new approaches to sealing, while making applications such as transportation more feasible. Reported results for anode-supported SOFCs show that cathode polarization resistance is the primary barrier to achieving high power densities at operating temperatures of 700 C and lower. This project aims to identify and develop composite cathodes that could reduce SOFC operating temperatures below 700 C. This effort focuses on study and use of (La,Sr)(Co,Fe)O{sub 3} (LSCF) based composite cathodes, which have arguably the best potential to substantially improve on the currently-used, (La,Sr)MnO{sub 3}-Yttria-stabilized Zirconia. During this Phase I, it was successfully demonstrated that high performances can be achieved with LSCF/Gadolinium-Doped Ceria composite cathodes on Ni-based anode supported cells operating at 700 C or lower. We studied electrochemical reactions at LSCF/Yttria-stabilized Zirconia (YSZ) interfaces, and observed chemical reactions between LSCF and YSZ. By using ceria electrolytes or YSZ electrolytes with ceria diffusion barrier layers, the chemical reactions between LSCF and electrolytes were prevented under cathode firing conditions necessary for the optimal adhesion of the cathodes. The protection provided by ceria layer is expected to be adequate for stable long-term cathode performances, but more testing is needed to verify this. Using ceria-based barrier layers, high performance Ni-YSZ anode supported cells have been demonstrated with maximum power densities of 0.8W/cm2 at 700 C and 1.6W/cm{sup 2} at 800 C. Ni-SDC anode supported cells with SDC electrolytes yielded >1W/cm{sup 2} at 600 C. We speculate that the power output of Ni-YSZ anode supported cell at 700 C and lower, was limited by the quality of the Ceria and Ceria YSZ interface. Improvements in the low-temperature performances are expected based on further development of barrier layer fabrication processes and optimization of cathode microstructure.

Ilwon Kim; Scott Barnett; Yi Jiang; Manoj Pillai; Nikkia McDonald; Dan Gostovic; Zhongryang Zhan; Jiang Liu

2004-01-31T23:59:59.000Z

346

Nano-web structures constructed with a cellulose acetate/lithium chloride/polyethylene oxide hybrid: Modeling, fabrication and characterization  

Science Journals Connector (OSTI)

Abstract Electrospun nano-web structures (ENWSs) were successfully fabricated from ionized binary solution of celluloseMn30/polyethylene oxideMn200 (CA/PEO of 0.5–1.5). Final concentration of polymers was 12% (w/v) in the solution, and lithium chloride was used as ionizing agent. Response surface methodology (RSM) was applied to the optimize fabrication of ENWSs. Results of multiple linear regression analysis revealed that the solution properties and \\{ENWSs\\} morphology were strongly influenced by CA/PEO. An increase in PEO amount increased the viscosity which is a function of molecular weight, and as a result raised the entanglement of polymeric solution but decreased the surface tension that all support nanofibers fabrication. The size of nanofibers decreased with reducing PEO and LiCl concentration. Increasing the content of LiCl promoted the electrical conductivity (EC) value; however, junction zones were formed. The overall optimum region was found to be at combined level of 1.5% CA/PEO and 0.49% (w/v) LiCl.

Atefeh Broumand; Zahra Emam-Djomeh; Faramarz Khodaiyan; Sasan Mirzakhanlouei; Driush Davoodi; Ali A. Moosavi-Movahedi

2015-01-01T23:59:59.000Z

347

Phase and strain distributions associated with reactive contaminants inside of a solid oxide fuel cell  

Science Journals Connector (OSTI)

A microfocused synchrotron x-ray diffraction method was used to reveal the quantitative distributions of phase fractions internal strains and their interdependences at different layer depths inside of a planar solid oxide fuel cell which was deactivated by chromium contamination through direct contact with the metallic interconnect under typical operating conditions. These observations provide insight into the mechanism of Cr poisoning. The method can serve as a versatile tool for studying the electrochemical devices with thin-layered construction such as batteries and fuel cells under static or in situ conditions.

Di-Jia Liu; Jonathan Almer

2009-01-01T23:59:59.000Z

348

REFORMULATION OF COAL-DERIVED TRANSPORTATION FUELS: SELECTIVE OXIDATION OF CARBON MONOXIDE ON METAL FOAM CATALYSTS  

SciTech Connect

Hydrocarbon fuels must be reformed in a series of steps to provide hydrogen for use in proton exchange membrane fuel cells (PEMFCs). Preferential oxidation (PROX) is one method to reduce the CO concentration to less than 10 ppm in the presence of {approx}40% H{sub 2}, CO{sub 2}, and steam. This will prevent CO poisoning of the PEMFC anode. Structured supports, such as ceramic monoliths, can be used for the PROX reaction. Alternatively, metal foams offer a number of advantages over the traditional ceramic monolith.

Paul Chin; Xiaolei Sun; George W. Roberts; Amornmart Sirijarhuphan; Sourabh Pansare; James G. Goodwin Jr; Richard W. Rice; James J. Spivey

2005-06-01T23:59:59.000Z

349

OPERATION OF SOLID OXIDE FUEL CELL ANODES WITH PRACTICAL HYDROCARBON FUELS  

SciTech Connect

This work was carried out to achieve a better understanding of how SOFC anodes work with real fuels. The motivation was to improve the fuel flexibility of SOFC anodes, thereby allowing simplification and cost reduction of SOFC power plants. The work was based on prior results indicating that Ni-YSZ anode-supported SOFCs can be operated directly on methane and natural gas, while SOFCs with novel anode compositions can work with higher hydrocarbons. While these results were promising, more work was clearly needed to establish the feasibility of these direct-hydrocarbon SOFCs. Basic information on hydrocarbon-anode reactions should be broadly useful because reformate fuel gas can contain residual hydrocarbons, especially methane. In the Phase I project, we have studied the reaction mechanisms of various hydrocarbons--including methane, natural gas, and higher hydrocarbons--on two kinds of Ni-containing anodes: conventional Ni-YSZ anodes and a novel ceramic-based anode composition that avoid problems with coking. The effect of sulfur impurities was also studied. The program was aimed both at achieving an understanding of the interactions between real fuels and SOFC anodes, and providing enough information to establish the feasibility of operating SOFC stacks directly on hydrocarbon fuels. A combination of techniques was used to provide insight into the hydrocarbon reactions at these anodes during SOFC operation. Differentially-pumped mass spectrometry was be used for product-gas analysis both with and without cell operation. Impedance spectroscopy was used in order to understand electrochemical rate-limiting steps. Open-circuit voltages measurements under a range of conditions was used to help determine anode electrochemical reactions. Life tests over a wide range of conditions were used to establish the conditions for stable operation of anode-supported SOFC stacks directly on methane. Redox cycling was carried out on ceramic-based anodes. Tests on sulfur tolerance of Ni-YSZ anodes were carried out.

Scott A. Barnett; Jiang Liu; Yuanbo Lin

2004-07-30T23:59:59.000Z

350

Pore-Scale Investigation of Mass Transport and Electrochemistry in a Solid Oxide Fuel Cell Anode  

SciTech Connect

The development and validation of a model for the study of pore-scale transport phenomena and electrochemistry in a Solid Oxide Fuel Cell (SOFC) anode are presented in this work. This model couples mass transport processes with a detailed reaction mechanism, which is used to model the electrochemical oxidation kinetics. Detailed electrochemical oxidation reaction kinetics, which is known to occur in the vicinity of the three-phase boundary (TPB) interfaces, is discretely considered in this work. The TPB regions connect percolating regions of electronic and ionic conducting phases of the anode, nickel (Ni) and yttria-stabilized zirconia (YSZ), respectively; with porous regions supporting mass transport of the fuel and product. A two-dimensional (2D), multi-species lattice Boltzmann method (LBM) is used to describe the diffusion process in complex pore structures that are representative of the SOFC anode. This diffusion model is discretely coupled to a kinetic electrochemical oxidation mechanism using localized flux boundary conditions. The details of the oxidation kinetics are prescribed as a function of applied activation overpotential and the localized hydrogen and water mole fractions. This development effort is aimed at understanding the effects of the anode microstructure within TPB regions. This work describes the methods used so that future studies can consider the details of SOFC anode microstructure.

Grew, K. N.; Joshi, A. S.; Peracchio, A. A.; Chiu, W. K. S.

2010-01-01T23:59:59.000Z

351

Redox instability, mechanical deformation, and heterogeneous damage accumulation in solid oxide fuel cell anodes  

Science Journals Connector (OSTI)

Mechanical integrity and damage tolerance represent two key challenges in the design of solid oxide fuel cells(SOFCs). In particular reduction and oxidation(redox) cycles and the associated large transformation strains have a notable impact on the mechanical stability and failure mode of SOFCanodes. In this study the deformation behavior under redox cycling is investigated computationally with an approach that provides a detailed microstructurally based view of heterogeneous damage accumulation behavior within an experimentally obtained nickel/yttria stabilized zirconia SOFCanode microstructure. Simulation results underscore the critical role that the microstructure plays in the mechanical deformation behavior of and failure within such materials.

F. Abdeljawad; G. J. Nelson; W. K. S. Chiu; M. Haataja

2012-01-01T23:59:59.000Z

352

Fabrication of superconducting metal-oxide textiles by heating impregnated polymeric material in a weakly oxidizing atmosphere  

SciTech Connect

A process is described for producing crystalline fibers, textiles or shapes comprised of YBa[sub 2]Cu[sub 3]O[sub 7[minus]x] where x varies from about 0 to about 0.4, said process comprising: (a) impregnating a preformed organic polymeric material with three metal compounds to provide metal elements in said material in substantially the atomic ratio occurring in said YBa[sub 2]Cu[sub 3]O[sub 7[minus]x]; (b) heating said impregnated material in a weakly oxidizing atmosphere containing from about 0.05% to about 2% oxygen by volume to a temperature sufficiently high to at least partially pyrolize and oxidize said organic material and at least partially oxidize said metal compounds substantially without ignition of said organic material and without formation of a molten phase or reaching a decomposition temperature of said YBa[sub 2]Cu[sub 3]O[sub 7[minus]x]; and (c) cooling the resulting material in at least a moderately oxidizing atmosphere to room temperature so as to obtain said fibers, textiles or shapes.

Van den Sype, J.S.

1993-07-13T23:59:59.000Z

353

Solid oxide fuel cell development at Topsoe Fuel Cell A/S and Risoe National Laboratory  

SciTech Connect

The consortium of Topsoe Fuel Cell A/S and Risoe National Laboratory has up-scaled its production capacity. Stacks are based on a compact thin plate multilayer design with metallic interconnects and 12x12 cm{sup 2} or 18x18 cm{sup 2} foot print. Larger (500 cm{sup 2}) cells are currently under evaluation. Stacks have been tested successfully for more than 13000 hours. Several 50 or 75 cell stacks in the 1+ kW power range have been tested successfully at a fuel utilisation of up to 92%. Multi stack modules consisting of four 75 cell stacks have been tested for more than 4000 hours with pre-reformed natural gas and modules consisting of twelve stacks are under development. Our SOFC program comprises development of next generation cells with porous ferritic steel is used as a cheap, ductile, robust cell support and the electrolyte is based on scandia-doped zirconia with improved durability. In collaboration with Waertsilae, a 24-stack prototype based on natural gas is being tested. The range of fuels have further been extended to include ethanol and coal syn-gas by development of a new coke resistant catalyst suitable for future SOFC technology.

Niels Christiansen; J.B. Hansen; H.H. Larsen (and others) [Topsoe Fuel Cell A/S, Lyngby (Denmark)

2007-07-01T23:59:59.000Z

354

U.S. DEPARTMENT OF ENERGY SOLID OXIDE FUEL CELLS PROGRAM | 2013 PROJECT PORTFOLIO  

NLE Websites -- All DOE Office Websites (Extended Search)

DEPARTMENT OF ENERGY DEPARTMENT OF ENERGY SOLID OXIDE FUEL CELLS PROGRAM | 2013 PROJECT PORTFOLIO 2 THIS PAGE INTENTIONALLY LEFT BLANK OFFICE OF FOSSIL ENERGY SOLID OXIDE FUEL CELLS PROGRAM | 2013 PROJECT PORTFOLIO 3 Disclaimer DISCLAIMER This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference therein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not neces-

355

The steady-state thermal-hydraulic performance of 3500 MWth metal and oxide fueled LMRs  

SciTech Connect

The thermal-hydraulic performance of a 3500 MWth metal and oxide fueled LMR is reported. Orifice zones are defined and coolant flowrates are given for use in safety analyses. The flux calculations were carried out in three-dimensional hexagonal-Z geometry using a finite differenced diffusion theory code. The heating calculations included the transport and deposition of gamma energy. The assembly temperature calculations were performed using a subchannel code.

Vilim, R.B.; Hill, R.N.

1989-03-01T23:59:59.000Z

356

Fabrication of heterojunction solar cells by improved tin oxide deposition on insulating layer  

DOE Patents (OSTI)

Highly efficient tin oxide-silicon heterojunction solar cells are prepared by heating a silicon substrate, having an insulating layer thereon, to provide a substrate temperature in the range of about 300.degree. C. to about 400.degree. C. and thereafter spraying the so-heated substrate with a solution of tin tetrachloride in a organic ester boiling below about 250.degree. C. Preferably the insulating layer is naturally grown silicon oxide layer.

Feng, Tom (Morris Plains, NJ); Ghosh, Amal K. (New Providence, NJ)

1980-01-01T23:59:59.000Z

357

The effect of Mn on the oxidation behavior and electrical conductivity of Fe–17Cr alloys in solid oxide fuel cell cathode atmosphere  

Science Journals Connector (OSTI)

Four Fe–17Cr alloys with various Mn contents between 0.0 and 3.0 wt.% are prepared for investigation of the effect of Mn content on the oxidation behavior and electrical conductivity of the Fe–Cr alloys for the application of metallic interconnects in solid oxide fuel cells (SOFCs). During the initial oxidation stage (within 1 min) at 750 °C in air, Cr is preferentially oxidized to form a layer of Cr2O3 type oxide in all the alloys, regardless the Mn content, with similar oxidation rate and oxide morphology. The subsequent oxidation of the Mn containing alloys is accelerated caused by the fast outward diffusion of Mn ions across the Cr2O3 type oxide layer to form Mn-rich (Mn, Cr)3O4 and Mn2O3 oxides on the top. After 700 h oxidation a multi-layered oxide scale is observed in the Mn containing alloys, which corresponds to a multi-stage oxidation kinetics in the alloys containing 0.5 and 1.0 wt.% of Mn. The oxidation rate and ASR of the oxide scale increase with the Mn content in the alloy changes from 0.0 to 3.0 wt.%. For the application of metallic interconnects in SOFCs, Mn-free Fe–17Cr alloy with conducting Cr free spinel coatings is preferred.

Bin Hua; Yonghong Kong; Wenying Zhang; Jian Pu; Bo Chi; Li Jian

2011-01-01T23:59:59.000Z

358

Microstructure, residual stress, and mechanical properties of thin film materials for a microfabricated solid oxide fuel cell  

E-Print Network (OSTI)

The microstructure and residual stress of sputter-deposited films for use in microfabricated solid oxide fuel cells are presented. Much of the work focuses on the characterization of a candidate solid electrolyte: Yttria ...

Quinn, David John, Sc. D. Massachusetts Institute of Technology

2006-01-01T23:59:59.000Z

359

Characterization of YSZ solid oxide fuel cells electrolyte deposited by atmospheric plasma spraying and low pressure plasma spraying  

Science Journals Connector (OSTI)

Yttria doped zirconia has been widely used as electrolyte materials for solid oxide fuel cells (SOFC). Plasma spraying is a cost-effective process to...2O3 stabilized ZrO2...(YSZ) layer was deposited by low press...

C. Zhang; H. L. Liao; W. Y. Li; G. Zhang; C. Coddet…

2006-12-01T23:59:59.000Z

360

Structure degradation and redistribution of alloying elements in austenitic steel of current collectors of solid oxide fuel cells in service  

Science Journals Connector (OSTI)

The degradation of the 10Kh23N18 steel structure with and ... as a switchgear material of a solid oxide fuel cell. Structural studies have shown no significant differences...

M. V. Degtyarev; V. F. Chukharev…

2013-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "oxide fuel fabrication" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


361

Modelling of thermo-mechanical and irradiation behavior of metallic and oxide fuels for sodium fast reactors  

E-Print Network (OSTI)

A robust and reliable code to model the irradiation behavior of metal and oxide fuels in sodium cooled fast reactors is developed. Modeling capability was enhanced by adopting a non-empirical mechanistic approach to the ...

Karahan, Aydin

2009-01-01T23:59:59.000Z

362

The development of control strategy for solid oxide fuel cell and micro gas turbine hybrid power system in ship application  

Science Journals Connector (OSTI)

A solid oxide fuel cell (SOFC) and micro gas turbine (MGT) hybrid power system is a newly developed and promising power technology for ship power systems. Compared to conventional power plants on commercial sh...

Jiqing He; Peilin Zhou; David Clelland

2014-12-01T23:59:59.000Z

363

MECHANICAL PROPERTIES OF Sc???Ce????Zr????O? ELECTROLYTE MATERIAL FOR INTERMEDIATE TEMPERATURE SOLID OXIDE FUEL CELLS  

E-Print Network (OSTI)

Scandia doped zirconia has been considered a candidate for electrolyte material in intermediate temperature Solid Oxide Fuel Cells (SOFCs) due to its high ionic conductivity, chemical stability and good electrochemical performance. The aim...

Lim, Wendy

2011-02-22T23:59:59.000Z

364

Assessment of Planar Solid Oxide Fuel Cell Technology Arthur D. Little, Inc.  

NLE Websites -- All DOE Office Websites (Extended Search)

Planar Solid Planar Solid Oxide Fuel Cell Technology Arthur D. Little, Inc. Acorn Park Cambridge, Massachusetts 02140-2390 Reference 39463-02 Report to: DOE FETC October 1999 EC39463 SOFC 1015 R3 2 Table of Contents 3 Background 4 Planar SOFC Technology Assessment 5 1 Project Objectives "Low Temperature" Planar SOFC Cost Analysis 2 Executive Summary EC39463 SOFC 1015 R3 3 3 Background 4 Planar SOFC Technology Assessment 5 1 Project Objectives "Low Temperature" Planar SOFC Cost Analysis 2 Executive Summary EC39463 SOFC 1015 R3 4 Project Objectives DOE FETC Fuel Cell Program In support of the 21st Century Fuel Cell Concept Team, we have assessed planar architectures for SOFC technology. Tasks Tasks Tasks * Literature Review of Planar SOFC Programs * Interviews with Major Developers

365

Cost Study for Manufacturing of Solid Oxide Fuel Cell Power Systems  

SciTech Connect

Solid oxide fuel cell (SOFC) power systems can be designed to produce electricity from fossil fuels at extremely high net efficiencies, approaching 70%. However, in order to penetrate commercial markets to an extent that significantly impacts world fuel consumption, their cost will need to be competitive with alternative generating systems, such as gas turbines. This report discusses a cost model developed at PNNL to estimate the manufacturing cost of SOFC power systems sized for ground-based distributed generation. The power system design was developed at PNNL in a study on the feasibility of using SOFC power systems on more electric aircraft to replace the main engine-mounted electrical generators [Whyatt and Chick, 2012]. We chose to study that design because the projected efficiency was high (70%) and the generating capacity was suitable for ground-based distributed generation (270 kW).

Weimar, Mark R.; Chick, Lawrence A.; Gotthold, David W.; Whyatt, Greg A.

2013-09-30T23:59:59.000Z

366

Creep Behavior of Glass/Ceramic Sealant Used in Solid Oxide Fuel Cells  

SciTech Connect

High operating temperature of solid oxide fuel cells require that sealant must function at high temperature between 600o and 900oC and in the oxidizing and reducing environments of fuel and air. It should be noted that creep deformation becomes relevant for a material when the operating temperature is near or exceeds half of its melting temperature (in degrees of Kelvin). The operating temperatures for most of the solid oxide fuel cells (SOFC) under development in the SECA program are around 800oC, which exceeds the glass transition temperature Tg for most glass ceramic materials. The goal of the study is to develop a creep model to capture the creep behavior of glass ceramic materials at high temperature and to investigate the effect of creep of glass ceramic sealant materials on stresses in glass seal and on the various interfaces of glass seal with other layers. The self-consistent creep models were incorporated into SOFC-MP and Mentat FC, and finite element analyses were performed to quantify the stresses in various parts. The stress in glass seals were released due to its creep behavior during the operating environments.

Liu, Wenning N.; Sun, Xin; Koeppel, Brian J.; Khaleel, Mohammad A.

2010-01-02T23:59:59.000Z

367

Structural, chemical, and electrochemical characteristics of LaSr2Fe2CrO9--based solid oxide fuel cell anodes  

E-Print Network (OSTI)

Available online 5 March 2012 Keywords: Solid oxide fuel cell Perovskite Oxide anode Redox Sulfur tolerance Solid oxide fuel cells with LaSr2Fe2CrO9-­Gd0.1Ce0.9O2- composite anodes were tested in H2, H2S-of-the-art solid oxide fuel cell (SOFC) anode is Ni-8-mole% yttria stabilized zirconia (YSZ), which performs very

Poeppelmeier, Kenneth R.

368

TAPE CALENDERING MANUFACTURING PROCESS FOR MULTILAYER THIN-FILM SOLID OXIDE FUEL CELLS  

SciTech Connect

This report summarizes the work performed by Hybrid Power Generation Systems, LLC during the Phases I and II under Contract DE-AC26-00NT40705 for the U. S. Department of Energy, National Energy Technology Laboratory (DOE/NETL) entitled ''Tape Calendering Manufacturing Process For Multilayer Thin-Film Solid Oxide Fuel Cells''. The main objective of this project was to develop the manufacturing process based on tape calendering for multilayer solid oxide fuel cells (SOFC's) using the unitized cell design concept and to demonstrate cell performance under specified operating conditions. Summarized in this report is the development and improvements to multilayer SOFC cells and the unitized cell design. Improvements to the multilayer SOFC cell were made in electrochemical performance, in both the anode and cathode, with cells demonstrating power densities of nearly 0.9 W/cm{sup 2} for 650 C operation and other cell configurations showing greater than 1.0 W/cm{sup 2} at 75% fuel utilization and 800 C. The unitized cell design was matured through design, analysis and development testing to a point that cell operation at greater than 70% fuel utilization was demonstrated at 800 C. The manufacturing process for both the multilayer cell and unitized cell design were assessed and refined, process maps were developed, forming approaches explored, and nondestructive evaluation (NDE) techniques examined.

Nguyen Minh; Kurt Montgomery

2004-10-01T23:59:59.000Z

369

SPS Fabrication of Tungsten-Rhenium Alloys in Support of NTR Fuels Development  

SciTech Connect

Abstract. Tungsten metal slugs were fabricated via Spark Plasma Sintering (SPS) of powdered metals at temperatures ranging from 1575 K to 1975 K and hold times of 5 minutes to 30 minutes, using powders with an average diameter of 7.8 ?m. Sintered tungsten specimens were found to have relative densities ranging from 83 % to 94 % of the theoretical density for tungsten. Consolidated specimens were also tested for their Vickers Hardness Number (VHN), which was fitted as a function of relative density; the fully consolidated VHN was extrapolated to be 381.45 kg/mm2. Concurrently, tungsten and rhenium powders with average respective diameters of 0.5 ?m and 13.3 ?m were pre-processed either by High-Energy-Ball-Milling (HEBM) or by homogeneous mixing to yield W-25at.%Re mixtures. The powder batches were sintered at temperatures of 1975 K and 2175 K for hold times ranging from 0 minutes to 60 minutes yielding relative densities ranging from 94% to 97%. The combination of HEBM and sintering showed a significant decrease in the inter-metallic phases compared to that of the homogenous mixing and sintering.

Jonathan A. Webb; Indrajit Charit; Cory Sparks; Darryl P. Butt; Megan Frary; Mark Carroll

2011-02-01T23:59:59.000Z

370

Performance of a solid oxide fuel cell CHP system coupled with a hot water storage tank for  

E-Print Network (OSTI)

Performance of a solid oxide fuel cell CHP system coupled with a hot water storage tank for single storage tank is studied. Thermal stratification in the tank increases the heat recovery performance of the residence. Two fuels are considered, namely syngas and natural gas. The tank model considers the temperature

Berning, Torsten

371

Safety Criticality Standards Using the French CRISTAL Code Package: Application to the AREVA NP UO{sub 2} Fuel Fabrication Plant  

SciTech Connect

Criticality safety evaluations implement requirements to proof of sufficient sub critical margins outside of the reactor environment for example in fuel fabrication plants. Basic criticality data (i.e., criticality standards) are used in the determination of sub critical margins for all processes involving plutonium or enriched uranium. There are several criticality international standards, e.g., ARH-600, which is one the US nuclear industry relies on. The French Nuclear Safety Authority (DGSNR and its advising body IRSN) has requested AREVA NP to review the criticality standards used for the evaluation of its Low Enriched Uranium fuel fabrication plants with CRISTAL V0, the recently updated French criticality evaluation package. Criticality safety is a concern for every phase of the fabrication process including UF{sub 6} cylinder storage, UF{sub 6}-UO{sub 2} conversion, powder storage, pelletizing, rod loading, assembly fabrication, and assembly transportation. Until 2003, the accepted criticality standards were based on the French CEA work performed in the late seventies with the APOLLO1 cell/assembly computer code. APOLLO1 is a spectral code, used for evaluating the basic characteristics of fuel assemblies for reactor physics applications, which has been enhanced to perform criticality safety calculations. Throughout the years, CRISTAL, starting with APOLLO1 and MORET 3 (a 3D Monte Carlo code), has been improved to account for the growth of its qualification database and for increasing user requirements. Today, CRISTAL V0 is an up-to-date computational tool incorporating a modern basic microscopic cross section set based on JEF2.2 and the comprehensive APOLLO2 and MORET 4 codes. APOLLO2 is well suited for criticality standards calculations as it includes a sophisticated self shielding approach, a P{sub ij} flux determination, and a 1D transport (S{sub n}) process. CRISTAL V0 is the result of more than five years of development work focusing on theoretical approaches and the implementation of user-friendly graphical interfaces. Due to its comprehensive physical simulation and thanks to its broad qualification database with more than a thousand benchmark/calculation comparisons, CRISTAL V0 provides outstanding and reliable accuracy for criticality evaluations for configurations covering the entire fuel cycle (i.e. from enrichment, pellet/assembly fabrication, transportation, to fuel reprocessing). After a brief description of the calculation scheme and the physics algorithms used in this code package, results for the various fissile media encountered in a UO{sub 2} fuel fabrication plant will be detailed and discussed. (authors)

Doucet, M.; Durant Terrasson, L.; Mouton, J. [AREVA-NP (France)

2006-07-01T23:59:59.000Z

372

Development and transfer of fuel fabrication and utilization technology for research reactors  

SciTech Connect

Approximately 300 research reactors supplied with US-enriched uranium are currently in operation in about 40 countries, with a variety of types, sizes, experiment capabilities and applications. Despite the usefulness and popularity of research reactors, relatively few innovations in their core design have been made in the last fifteen years. The main reason can be better understood by reviewing briefly the history of research reactor fuel technology and enrichment levels. Stringent requirements on the enrichment of the uranium to be used in research reactors were considered and a program was launched to assist research reactors in continuing their operation with the new requirements and with minimum penalties. The goal of the new program, the Reduced Enrichment Research and Test Reactor (RERTR) Program, is to develop the technical means to utilize LEU instead of HEU in research reactors without significant penalties in experiment performance, operating costs, reactor modifications, and safety characteristics. This paper reviews briefly the RERTR Program activities with special emphasis on the technology transfer aspects of interest to this conference.

Travelli, A.; Domagala, R.F.; Matos, J.E.; Snelgrove, J.L.

1982-01-01T23:59:59.000Z

373

Efficient Polymer Solar Cells Fabricated on Poly(3,4-ethylenedioxythiophene):Poly(styrenesulfonate)-Etched Old Indium Tin Oxide Substrates  

SciTech Connect

In organic electronic devices, indium tin oxide (ITO) and poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) are the most common transparent electrode and anodic buffer layer materials, respectively. A widespread concern is that PEDOT:PSS is acidic and etches ITO. We show that this issue is not serious: only a few nanometers of ITO are etched in typical device processing conditions and storage thereafter; conductivity losses are affordable; and optical transmission gains further offset these losses. Organic photovoltaic (OPV) devices fabricated on old ITO (with PEDOT:PSS history) were similar or higher in efficiency than devices on fresh ITO. Poly[[4,8-bis[(2-ethylhexyl)oxy]benzo[1,2-b:4,5-b?]dithiophene-2,6-diyl][3-fluoro-2-[(2-ethylhexyl)carbonyl]thieno[3,4-b]thiophenediyl

Elshobaki, Moneim [Mansoura University; Anderegg, James [Ames Laboratory; Chaudhary, Sumit [Ames Laboratory

2014-08-13T23:59:59.000Z

374

Nickel based anodes for single chamber solid oxide fuel cells : a catalytic study Geoffroy Gadacz, Sorina Udroiu, Jean-Paul Viricelle, Christophe Pijolat, Michle Pijolat  

E-Print Network (OSTI)

Nickel based anodes for single chamber solid oxide fuel cells : a catalytic study Geoffroy Gadacz Single chamber solid oxide fuel cells (SCFC) are an alternative concept to traditional SOFC-gas-shift equilibrium. Introduction Fifteen years ago, Hibino (1) has shown the feasibility of a fuel cell consisting

Boyer, Edmond

375

Lithium manganese oxide films fabricated by electron beam directed vapor deposition  

E-Print Network (OSTI)

material for high energy den- sity battery applications.7,8 Lithium­transition metal oxide films can.2. After annealing in air at 700 °C, thin films grown with a low jet speed had a cubic spinel structure Li/Li-ion batteries. © 2008 American Vacuum Society. DOI: 10.1116/1.2823488 I. INTRODUCTION Thin film

Wadley, Haydn

376

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

SciTech Connect

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.

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

2009-04-24T23:59:59.000Z

377

Use of curium spontaneous fission neutrons for safeguardability of remotely-handled nuclear facilities: Fuel fabrication in pyroprocessing  

Science Journals Connector (OSTI)

Abstract Advanced nuclear reactor systems (NESs) will utilize remotely-handled facilities in which batch-type processing will occur in hot cells. There are no current formalized criteria for International Atomic Energy Agency (IAEA) safeguards for these systems. This creates new challenges to develop methodologies for demonstrating the safeguardability of these facilities. A High Reliability Safeguards (HRS) approach therefore has been proposed to enhance intrinsic proliferation resistance by establishing an envelope of adaptable functional components as part of a facility design strategy. Additionally, system assessment can be modeled concurrently with safety and physical security by a risk-informed approach. The HRS approach is currently applied to a commercial pyroprocessing facility as an example system. A scoping study is presented as the first in a series of quantitative modeling efforts to extend the HRS approach. These efforts currently focus on investigating the magnitude of neutron fluxes due to spontaneous fission of curium for commercial batch sizes and held up materials for important processes in the system. Here, the fuel fabrication process is studied. The intent of these initial studies is to learn how the intrinsic properties of materials in the pyroprocessing system will affect facility design and safeguards. The model presented in this paper is intended to be adaptable to more practical and complex scenarios in order to evaluate the safeguardability of remotely-handled nuclear facilities.

R.A. Borrelli

2013-01-01T23:59:59.000Z

378

A thermally self-sustained micro-power plant with integrated micro-solid oxide fuel cells, micro-reformer and functional  

E-Print Network (OSTI)

A thermally self-sustained micro-power plant with integrated micro-solid oxide fuel cells, micro Micro-solid oxide fuel cell Thin films Butane reformation Chemical micro-reactors Thermally independent 2014 Accepted 8 February 2014 Available online xxx a b s t r a c t Low temperature micro-solid oxide

Daraio, Chiara

379

Multi objective optimization of solid oxide fuel cell stacks considering parameter effects: Fuel utilization and hydrogen cost  

Science Journals Connector (OSTI)

In the context of stationary power generation fuel cell based systems are being predicted as a valuable option to tabernacle the thermodynamic cycle based power plants. In this paper multi objective optimization approach is used to optimize the planer solid oxide fuel cell (SOFC) stacks performance using genetic algorithm technique. Multi objective optimization generates the most attractive operating conditions of a SOFC system. This allows performing the optimization of the system regarding to two different objectives. Two pairs of different objectives are considered in this paper as distinguished strategies. In the first strategy minimization of the breakeven per-unit energy cost ($/kWh) and maximization of the output power is considered. Similarly two other objectives are also considered in the second strategy as minimization of the breakeven per-unit energy cost ($/kWh) and maximization of the electrical efficiency. Optimization of the first strategy predicts a maximum power output of 108.33?kW at a breakeven per-unit energy cost of 0.51 $/kWh and minimum breakeven per-unit energy cost of 0.30 $/kWh at a power of 42.18?kW. In the second strategy maximum efficiency of 63.93% at a breakeven per-unit energy cost of 0.42$/kWh is predicted while minimum breakeven per-unit energy cost of 0.25 $/kWh at efficiency of 48.3% is obtained. At the end evaluation of parameter effects on multi objective optimization regarding different hydrogen costs and fuel utilization factors are presented. It is worthy to note that the sensitivity analysis for multi objective optimization can be considered both as an advanced analysis tool and as support to technology managers engineers and decision makers when working by such as systems.

Atefeh Behzadi Forough; Ramin Roshandel

2013-01-01T23:59:59.000Z

380

Zero Emission Power Plants Using Solid Oxide Fuel Cells and Oxygen Transport Membranes  

SciTech Connect

Siemens Westinghouse Power Corp. (SWPC) is engaged in the development of Solid Oxide Fuel Cell stationary power systems. SWPC has combined DOE Developmental funds with commercial customer funding to establish a record of successful SOFC field demonstration power systems of increasing size. SWPC will soon deploy the first unit of a newly developed 250 kWe Combined Heat Power System. It will generate electrical power at greater than 45% electrical efficiency. The SWPC SOFC power systems are equipped to operate on lower number hydrocarbon fuels such as pipeline natural gas, which is desulfurized within the SOFC power system. Because the system operates with a relatively high electrical efficiency, the CO2 emissions, {approx}1.0 lb CO2/ kW-hr, are low. Within the SOFC module the desulfurized fuel is utilized electrochemically and oxidized below the temperature for NOx generation. Therefore the NOx and SOx emissions for the SOFC power generation system are near negligible. The byproducts of the power generation from hydrocarbon fuels that are released into the environment are CO2 and water vapor. This forward looking DOE sponsored Vision 21 program is supporting the development of methods to capture and sequester the CO2, resulting in a Zero Emission power generation system. To accomplish this, SWPC is developing a SOFC module design, to be demonstrated in operating hardware, that will maintain separation of the fuel cell anode gas, consisting of H2, CO, H2O and CO2, from the vitiated air. That anode gas, the depleted fuel stream, containing less than 18% (H2 + CO), will be directed to an Oxygen Transport Membrane (OTM) Afterburner that is being developed by Praxair, Inc.. The OTM is supplied air and the depleted fuel. The OTM will selectively transport oxygen across the membrane to oxidize the remaining H2 and CO. The water vapor is then condensed from the totally 1.5.DOC oxidized fuel stream exiting the afterburner, leaving only the CO2 in gaseous form. That CO2 can then be compressed and sequestered, resulting in a Zero Emission power generation system operating on hydrocarbon fuel that adds only water vapor to the environment. Praxair has been developing oxygen separation systems based on dense walled, mixed electronic, oxygen ion conducting ceramics for a number of years. The oxygen separation membranes find applications in syngas production, high purity oxygen production and gas purification. In the SOFC afterburner application the chemical potential difference between the high temperature SOFC depleted fuel gas and the supplied air provides the driving force for oxygen transport. This permeated oxygen subsequently combusts the residual fuel in the SOFC exhaust. A number of experiments have been carried out in which simulated SOFC depleted fuel gas compositions and air have been supplied to either side of single OTM tubes in laboratory-scale reactors. The ceramic tubes are sealed into high temperature metallic housings which precludes mixing of the simulated SOFC depleted fuel and air streams. In early tests, although complete oxidation of the residual CO and H2 in the simulated SOFC depleted fuel was achieved, membrane performance degraded over time. The source of degradation was found to be contaminants in the simulated SOFC depleted fuel stream. Following removal of the contaminants, stable membrane performance has subsequently been demonstrated. In an ongoing test, the dried afterburner exhaust composition has been found to be stable at 99.2% CO2, 0.4% N2 and 0.6%O2 after 350 hours online. Discussion of these results is presented. A test of a longer, commercial demonstration size tube was performed in the SWPC test facility. A similar contamination of the simulated SOFC depleted fuel stream occurred and the performance degraded over time. A second test is being prepared. Siemens Westinghouse and Praxair are collaborating on the preliminary design of an OTM equipped Afterburner demonstration unit. The intent is to test the afterburner in conjunction with a reduced size SOFC test module that has the anode gas separati

Shockling, Larry A.; Huang, Keqin; Gilboy, Thomas E. (Siemens Westinghouse Power Corporation); Christie, G. Maxwell; Raybold, Troy M. (Praxair, Inc.)

2001-11-06T23:59:59.000Z

Note: This page contains sample records for the topic "oxide fuel fabrication" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


381

Solid State Energy Conversion Alliance (SECA) Solid Oxide Fuel Cell Program  

SciTech Connect

This report summarizes the work performed for Phase I (October 2001 - August 2006) under Cooperative Agreement DE-FC26-01NT41245 for the U. S. Department of Energy, National Energy Technology Laboratory (DOE/NETL) entitled 'Solid State Energy Conversion Alliance (SECA) Solid Oxide Fuel Cell Program'. The program focuses on the development of a low-cost, high-performance 3-to-10-kW solid oxide fuel cell (SOFC) system suitable for a broad spectrum of power-generation applications. During Phase I of the program significant progress has been made in the area of SOFC technology. A high-efficiency low-cost system was designed and supporting technology developed such as fuel processing, controls, thermal management, and power electronics. Phase I culminated in the successful demonstration of a prototype system that achieved a peak efficiency of 41%, a high-volume cost of $724/kW, a peak power of 5.4 kW, and a degradation rate of 1.8% per 500 hours. . An improved prototype system was designed, assembled, and delivered to DOE/NETL at the end of the program. This prototype achieved an extraordinary peak efficiency of 49.6%.

Nguyen Minh

2006-07-31T23:59:59.000Z

382

Microstructural coarsening effects on redox instability and mechanical damage in solid oxide fuel cell anodes  

Science Journals Connector (OSTI)

In state-of-the-art high temperature solid oxide fuel cells (SOFCs) a porous composite of nickel and yttria stabilized zirconia (Ni/YSZ) is employed as the anode. The rapid oxidation of Ni into NiO is regarded as the main cause of the so-called reduction-oxidation (redox) instability in Ni/YSZ anodes due to the presence of extensive bulk volume changes associated with this reaction. As a consequence the development of internal stresses can lead to performance degradation and/or structural failure. In this study we employ a recently developed continuum formalism to quantify the mechanical deformation behavior and evolution of internal stresses in Ni/YSZ porous anodes due to re-oxidation. In our approach a local failure criterion is coupled to the continuum framework in order to account for the heterogeneous damage accumulation in the YSZ phase. The hallmark of our approach is the ability to track the spatial evolution of mechanical damage and capture the interaction of YSZ damaged regions with the local microstructure. Simulation results highlight the importance of the microstructure characterized by Ni to YSZ particle size ratio on the redox behavior and damage accumulation in as-synthesized SOFC anode systems. Moreover a redox-strain-to-failure criterion is developed to quantify the degree by which coarsened anode microstructures become more susceptible to mechanical damage during re-oxidation.

F. Abdeljawad; M. Haataja

2013-01-01T23:59:59.000Z

383

STABLE HIGH CONDUCTIVITY BILAYERED ELECTROLYTES FOR LOW TEMPERATURE SOLID OXIDE FUEL CELLS  

SciTech Connect

A bilayer electrolyte consisting of acceptor-doped ceria (on the fuel/reducing side) and cubic-stabilized bismuth oxide (on the oxidizing side) was developed. The bilayer electrolyte that was developed showed significant improvement in open-circuit potential versus a typical ceria based SOFC. Moreover, the OCP of the bilayer cells increased as the thickness of the bismuth oxide layer increased relative to the ceria layer. Thereby, verifying the bilayer concept. Although, because of the absence of a suitable cathode (a problem we are still working assiduously to solve), we were unable to obtain power density curves, our modeling work predicts a reduction in electrolyte area specific resistance of two orders of magnitude over cubic-stabilized zirconia and projects a maximum power density of 9 W/m{sup 2} at 800 C and 0.09 W/m{sup 2} at 500 C. Towards the development of the bilayer electrolyte other significant strides were made. Among these were, first, the development of a, bismuth oxide based, oxide ion conductor with the highest conductivity (0.56 S/cm at 800 C and 0.043 S/cm at 500 C) known to date. Second, a physical model of the defect transport mechanisms and the driving forces for the ordering phenomena in bismuth oxide and other fluorite systems was developed. Third, a model for point defect transport in oxide mixed ionic-electronic conductors was developed, without the typical assumption of a uniform distribution of ions and including the effect of variable loads on the transport properties of an SOFC (with either a single or bilayer electrolyte).

Eric D. Wachsman; Keith L. Duncan

2002-09-30T23:59:59.000Z

384

Sputter deposition of cermet fuel electrodes for solid oxide fuel cells  

Science Journals Connector (OSTI)

We describe the structure and electrochemical properties of cermetthin films composed of 50 vol?% Ni and Y?stabilized ZrO2 (YSZ) of interest for solid?oxidefuel cell(SOFC)electrode applications. The Ni–YSZ films—deposited by dc reactive magnetron sputtering of Ni–Zr–Y targets in Ar–O2 mixtures—were porous two?phase and exhibited an equiaxed structure with grain sizes of ?35 nm. The typical conductivity of 103 ??1?cm?1 was similar to that of bulk Ni–YSZ. Impedance spectroscopy was used to characterize reactions of H2/H2O fuel gases at the interfaces between Ni–YSZ films and YSZ electrolytes. The spectra typically showed two arcs attributed to charge transfer and gas diffusion. Either high sputter gas pressures of 40 mTorr or roughened YSZ substrate surfaces were necessary to obtain sufficient film porosity. Electrochemical resistance values of 0.15 to 0.35 ??cm2 were measured at 750?°C in 97% H2+3% H2O lower than those for bulk Ni–YSZ and low enough for high?power?density SOFC operation. The low resistance values were probably due to a small grain size. Using a 40 mTorr pressure and a roughened substrate led to film cracking apparently due to tensile stresses while using 20 mTorr and a polished substrate led to a too?dense film. Either change increased the electrochemical resistance by ?100 times.

T. Tsai; S. A. Barnett

1995-01-01T23:59:59.000Z

385

Performance of solid oxide fuel cells approaching the two-dimensional limit  

Science Journals Connector (OSTI)

We model electrochemical kinetics and physical conduction mechanisms for carrier transport in electrolyte membranes to determine the limits of dimensionality reduction (down to 1?nm) on maximum power output of solid oxide fuel cells with symmetric Pt electrodes. Using Y-doped ZrO2 we find a minimum thickness of ?6?nm to realize near ideal chemical potential in such fuel cells which is limited by electronic breakdown when approaching the dielectric breakdown strength. For larger electrolyte thicknesses the greatest source of electronic leakage influencing power loss is from Ohmic transport of minority carriers and emission of trapped carriers. For porous metallic electrodes an ideal microstructure with the particle size comparable to particle spacing dimensions is found to accurately model experimental results. The role of electronic trap states in the electrolyte band gap on power density characteristics is highlighted.

K. Kerman; S. Ramanathan

2014-01-01T23:59:59.000Z

386

Short time proton dynamics in bulk ice and in porous anode solid oxide fuel cell materials  

SciTech Connect

Oxygen reduction and incorporation into solid electrolytes and the reverse reaction of oxygen evolution play a cru-cial role in Solid Oxide Fuel Cell (SOFC) applications. However a detailed un derstanding of the kinetics of the cor-responding reactions, i.e. on reaction mechanisms, rate limiting steps, reaction paths, electrocatalytic role of materials, is still missing. These include a thorough characterization of the binding potentials experienced by protons in the lattice. We report results of Inelastic Neutron Scattering (INS) measurements of the vibrational state of the protons in Ni- YSZ highly porous composites (75% to 90% ), a ceramic-metal material showing a high electrical conductivity and ther mal stability, which is known to be most effectively used as anodes for solid ox ide fuel cells. The results are compared with INS and Deep Inelastic Neutron Scattering (DINS) experiments on the proton binding states in bulk ice.

Basoli, Francesco [Universitŕ degli Studi di Roma Tor Vergata, Italy] [Universitŕ degli Studi di Roma Tor Vergata, Italy; Senesi, Roberto [ORNL] [ORNL; Kolesnikov, Alexander I [ORNL] [ORNL; Licoccia, Silvia [NAST Center, University of Roma "Tor Vergata"] [NAST Center, University of Roma "Tor Vergata"

2014-01-01T23:59:59.000Z

387

Stripping of organic compounds from wastewater as an auxiliary fuel of regenerative thermal oxidizer  

Science Journals Connector (OSTI)

Organic solvents with different volatilities are widely used in various processes and generate air and water pollution problems. In the cleaning processes of electronics industries, most volatile organic compounds (VOCs) are vented to air pollution control devices while most non-volatile organic solvents dissolve in the cleaning water and become the major sources of COD in wastewater. Discharging a high-COD wastewater stream to wastewater treatment facility often disturbs the treatment performance. A pretreatment of the high-COD wastewater is therefore highly desirable. This study used a packed-bed stripping tower in combination with a regenerative thermal oxidizer to remove the COD in the wastewater from a printed circuit board manufacturing process and to utilize the stripped organic compounds as the auxiliary fuel of the RTO. The experimental results showed that up to 45% of the COD could be removed and 66% of the RTO fuel could be saved by the combined treatment system.

Meng-Wen Chang; Jia-Ming Chern

2009-01-01T23:59:59.000Z

388

Comparison between two optimization strategies for solid oxide fuel cell–gas turbine hybrid cycles  

Science Journals Connector (OSTI)

This paper compares the performance characteristics of a combined power system with solid oxide fuel cell (SOFC) and gas turbine (GT) working under two thermodynamic optimization strategies. Expressions of the optimized power output and efficiency for both the subsystems and the SOFC-GT hybrid cycle are derived. Optimal performance characteristics are discussed and compared in detail through a parametric analysis to evaluate the impact of multi-irreversibilities that take into account on the system behaviour. It is found that there exist certain new optimum criteria for some important design and operating parameters. Engineers should find the methodologies developed in this paper useful in the optimal design and practical operation of complex hybrid fuel cell power plants.

Yingru Zhao; Nilay Shah; Nigel Brandon

2011-01-01T23:59:59.000Z

389

Selective Production of Hydrogen for Fuel Cells Via Oxidative Steam Reforming of Methanol Over CuZnAl Oxide Catalysts: Effect of Substitution of Zirconium and Cerium on the Catalytic Performance  

Science Journals Connector (OSTI)

H2 fuel, for fuel cells, is traditionally produced from methanol by the endothermic steam reforming of methanol (SRM). Partial oxidation of methanol (POM), which is highly exothermic, has also been suggested as ....

S. Velu; K. Suzuki

2003-04-01T23:59:59.000Z

390

Application of LaSr2Fe2CrO9-in Solid Oxide Fuel Cell Jacob M. Haag,a  

E-Print Network (OSTI)

Application of LaSr2Fe2CrO9- in Solid Oxide Fuel Cell Anodes Jacob M. Haag,a Brian D. Madsen composition LaSr2Fe2CrO9- was tested for application as an anode material for solid oxide fuel cells. Despite 28, 2008. Ni­yttria stabilized zirconia YSZ cermets are commonly used in solid oxide fuel cell SOFC

Poeppelmeier, Kenneth R.

391

Microstructure and properties of barium cerate based electrolytes for solid oxide fuel cells  

SciTech Connect

Barium cerate based ceramics have been widely reported to have high ionic conductivity and hold promise as electrolyte materials for intermediate-temperature solid oxide fuel cells (SOFC`s). Samples of niobium-doped barium cerate have been produced with a variety of microstructures. Many parameters affecting the final microstructure of the electrolyte materials have been systematically investigated. The conductivity of the electrolyte materials produced have been studied using impedance spectroscopy to understand the effect of microstructure on the desired properties of barium cerate based electrolytes.

Rauch, W.L.; Liu, M. [Georgia Institute of Technology, Atlanta, GA (United States)

1996-12-31T23:59:59.000Z

392

A Quasi-Two-Dimensional Electrochemistry Modeling Tool for Planar Solid Oxide Fuel Cell Stacks  

SciTech Connect

A two-dimensional numerical model is presented for the efficient computation of the steady-state current density, species concentration, and temperature distributions in planar solid oxide fuel cell stacks. The model reduction techniques, engineering approximations, and numerical procedures used to simulate the stack physics while maintaining adequate computational speed are discussed. The results of the model for benchmark cases with and without on-cell methane reformation are presented with comparisons to results from other research described in the literature. The capabilities, performance, and scalability of the model for the study of large multi-cell stacks are then demonstrated.

Lai, Canhai; Koeppel, Brian J.; Choi, Kyoo Sil; Recknagle, Kurtis P.; Sun, Xin; Chick, Lawrence A.; Korolev, Vladimir N.; Khaleel, Mohammad A.

2011-03-15T23:59:59.000Z

393

Solid oxide fuel cells having porous cathodes infiltrated with oxygen-reducing catalysts  

DOE Patents (OSTI)

Solid-oxide fuel cells include an electrolyte and an anode electrically coupled to a first surface of the electrolyte. A cathode is provided, which is electrically coupled to a second surface of the electrolyte. The cathode includes a porous backbone having a porosity in a range from about 20% to about 70%. The porous backbone contains a mixed ionic-electronic conductor (MIEC) of a first material infiltrated with an oxygen-reducing catalyst of a second material different from the first material.

Liu, Meilin; Liu, Ze; Liu, Mingfei; Nie, Lifang; Mebane, David Spencer; Wilson, Lane Curtis; Surdoval, Wayne

2014-08-12T23:59:59.000Z

394

OXIDATION OF MERCURY ACROSS SCR CATALYSTS IN COAL-FIRED POWER PLANTS BURNING LOW RANK FUELS  

SciTech Connect

This is the seventh Quarterly Technical Report for DOE Cooperative Agreement No: DE-FC26-03NT41728. The objective of this program is to measure the oxidation of mercury in flue gas across SCR catalyst in a coal-fired power plant burning low rank fuels using a slipstream reactor containing multiple commercial catalysts in parallel. The Electric Power Research Institute (EPRI) and Argillon GmbH are providing co-funding for this program. This program contains multiple tasks and good progress is being made on all fronts. During this quarter, a model of Hg oxidation across SCRs was formulated based on full-scale data. The model took into account the effects of temperature, space velocity, catalyst type and HCl concentration in the flue gas.

Constance Senior

2004-10-29T23:59:59.000Z

395

OXIDATION OF MERCURY ACROSS SCR CATALYSTS IN COAL-FIRED POWER PLANTS BURNING LOW RANK FUELS  

SciTech Connect

This is the fifth Quarterly Technical Report for DOE Cooperative Agreement No: DE-FC26-03NT41728. The objective of this program is to measure the oxidation of mercury in flue gas across SCR catalyst in a coal-fired power plant burning low rank fuels using a slipstream reactor containing multiple commercial catalysts in parallel. The Electric Power Research Institute (EPRI) and Argillon GmbH are providing co-funding for this program. This program contains multiple tasks and good progress is being made on all fronts. During this quarter, the available data from laboratory, pilot and full-scale SCR units was reviewed, leading to hypotheses about the mechanism for mercury oxidation by SCR catalysts.

Constance Senior

2004-04-30T23:59:59.000Z

396

Detailed chemical kinetic mechanism for the oxidation of biodiesel fuels blend surrogate.  

SciTech Connect

Detailed chemical kinetic mechanisms were developed and used to study the oxidation of two large unsaturated esters: methyl-5-decenoate and methyl-9-decenoate. These models were built from a previous methyl decanoate mechanism and were compared with rapeseed oil methyl esters oxidation experiments in a jet stirred reactor. A comparative study of the reactivity of these three oxygenated compounds was performed and the differences in the distribution of the products of the reaction were highlighted showing the influence of the presence and the position of a double bond in the chain. Blend surrogates, containing methyl decanoate, methyl-5-decenoate, methyl-9-decenoate and n-alkanes, were tested against rapeseed oil methyl esters and methyl palmitate/n-decane experiments. These surrogate models are realistic kinetic tools allowing the study of the combustion of biodiesel fuels in diesel and homogeneous charge compression ignition engines.

Herbinet, O; Pitz, W J; Westbrook, C K

2009-07-21T23:59:59.000Z

397

Thermoeconomic Modeling and Parametric Study of Hybrid Solid Oxide Fuel Cell â Gas Turbine â Steam Turbine Power Plants Ranging from 1.5 MWe to 10 MWe.  

E-Print Network (OSTI)

??Detailed thermodynamic, kinetic, geometric, and cost models are developed, implemented, and validated for the synthesis/design and operational analysis of hybrid solid oxide fuel cell (SOFC)… (more)

Arsalis, Alexandros

2007-01-01T23:59:59.000Z

398

Pyroprocessing of oxidized sodium-bonded fast reactor fuel - An experimental study of treatment options for degraded EBR-II fuel  

SciTech Connect

An experimental study was conducted to assess pyrochemical treatment options for degraded EBR-II fuel. As oxidized material, the degraded fuel would need to be converted back to metal to enable electrorefining within an existing electro-metallurgical treatment process. A lithium-based electrolytic reduction process was studied to assess the efficacy of converting oxide materials to metal with a particular focus on the impact of zirconium oxide and sodium oxide on this process. Bench-scale electrolytic reduction experiments were performed in LiCl-Li{sub 2}O at 650 C. degrees with combinations of manganese oxide (used as a surrogate for uranium oxide), zirconium oxide, and sodium oxide. In the absence of zirconium or sodium oxide, the electrolytic reduction of MnO showed nearly complete conversion to metal. The electrolytic reduction of a blend of MnO-ZrO{sub 2} in LiCl - 1 wt% Li{sub 2}O showed substantial reduction of manganese, but only 8.5% of the zirconium was found in the metal phase. The electrolytic reduction of the same blend of MnO-ZrO{sub 2} in LiCl - 1 wt% Li{sub 2}O - 6.2 wt% Na{sub 2}O showed substantial reduction of manganese, but zirconium reduction was even less at 2.4%. This study concluded that ZrO{sub 2} cannot be substantially reduced to metal in an electrolytic reduction system with LiCl - 1 wt% Li{sub 2}O at 650 C. degrees due to the perceived preferential formation of lithium zirconate. This study also identified a possible interference that sodium oxide may have on the same system by introducing a parasitic and cyclic reaction of dissolved sodium metal between oxidation at the anode and reduction at the cathode. When applied to oxidized sodium-bonded EBR-II fuel (e.g., U-10Zr), the prescribed electrolytic reduction system would not be expected to substantially reduce zirconium oxide, and the accumulation of sodium in the electrolyte could interfere with the reduction of uranium oxide, or at least render it less efficient.

Hermann, S.D.; Gese, N.J. [Separations Department, Idaho National Laboratory, P.O. Box 1625, Idaho Falls, ID 83415 (United States); Wurth, L.A. [Zinc Air Inc., 5314-A US Hwy 2 West, Columbia Falls, MT 59912 (United States)

2013-07-01T23:59:59.000Z

399

Two-step fuel oxidation to improve efficiency in the conversion of chemical energy into work  

SciTech Connect

It is well known that in the conversion of chemical exergy into work a remarkable percentage of exergy is destroyed during the combustion process. Obviously, hypothetical reversible combustions, as proposed in some papers, are not to be taken into account. On the contrary, recent studies of a new system to increase the efficiency of the conversion of chemical exergy into work appear interesting. The proposed system includes a gas turbine system with chemical-looping combustion where a metal oxide is used as an oxygen carrier. Instead of conventional combustion, the oxidation of fuel is carried out in a two-step reaction. The first step is an endothermic reaction in which a metal oxide is reduced by fuel at low temperature and the second step an exothermic reaction in which the products of the former reaction are subjected to oxidation. The thermal energy of low exergy value in the exhaust gas is employed to drive the endothermic reaction. Various systems have been proposed and tested. The power-generation system (called CLSA), with chemical-looping combustion and air saturation seems the most convenient. When only saturated air is used, exergy destruction becomes small in the middle- and low temperature range. However, the inefficiency in the high temperature range remains. On the other hand, when only chemical-looping combustion is used, exergy destruction becomes small in the high- and middle temperature range. However, the inefficiency in the low-temperature range is now not removed. When both technologies are combined, exergy efficiency may become much greater than that obtained from each individual process. The synergistic effect of combining these two technologies is analogous to the improvement achieved when a combined system was designed as a new power-generation system by combining a gas turbine with a steam turbine. For a model system, an exergy efficiency of 53.3% is obtained when the process water is recovered and a value of about 55% is obtained when water is not recovered. A significant advantage of the CLSA system is that CO{sub 2} can be easily recovered. The CO{sub 2} produced in the reduction reactor is not diluted by air since air and fuel enter different reactors. This is quite different from a traditional combustor in which CO{sub 2} is diluted in air and hence cannot be concentrated and separated economically. In the CLSA system, since the exhaust gas from the reduction reactor is composed only of high-concentration CO{sub 2} and water vapor, CO{sub 2} can be easily recovered by cooling the exhaust gas and removing the liquid water, i.e. very little energy expenditure is required for recovering CO{sub 2} from the exhaust gas. The recovered CO{sub 2} may be utilized, e.g., in artificial photosynthesis, whereas a simple recovery without any utilization but only to reduce greenhouse effect seems questionable. Another significant characteristic of CLSA system is that the most of the water vapor in the exhaust gas can be recovered by cooling the exhaust gas from the oxidation reactor. In chemical-looping combustion, fuel is not burned directly and the gas discharged from the oxidation reactor has no impurities from the fuel. Hence, there will be no corrosion of the apparatus when the exhaust gas is cooled to a very low temperature and low cost materials can be utilized for the heat exchangers. Because of the recycling of the most part of water, the CLSA system can be used in locations with limited water resources. Chemical-looping combustion system can be also combined with an integrated coal gasification and this topic appears very interesting. Indeed, to achieve better conversion efficiencies and lower pollutant emissions in power plants, new technologies that combines coal gasification with a gas turbine based combined cycle have been extensively studied worldwide.

Bisio, G.; Rubatto, R.; Marletta, L.

1998-07-01T23:59:59.000Z

400

OXIDATION OF MERCURY ACROSS SCR CATALYSTS IN COAL-FIRED POWER PLANTS BURNING LOW RANK FUELS  

SciTech Connect

The objectives of this program were to measure the oxidation of mercury in flue gas across SCR catalyst in a coal-fired power plant burning low rank fuels using a slipstream reactor containing multiple commercial catalysts in parallel and to develop a greater understanding of mercury oxidation across SCR catalysts in the form of a simple model. The Electric Power Research Institute (EPRI) and Argillon GmbH provided co-funding for this program. REI used a multicatalyst slipstream reactor to determine oxidation of mercury across five commercial SCR catalysts at a power plant that burned a blend of 87% subbituminous coal and 13% bituminous coal. The chlorine content of the blend was 100 to 240 {micro}g/g on a dry basis. Mercury measurements were carried out when the catalysts were relatively new, corresponding to about 300 hours of operation and again after 2,200 hours of operation. NO{sub x}, O{sub 2} and gaseous mercury speciation at the inlet and at the outlet of each catalyst chamber were measured. In general, the catalysts all appeared capable of achieving about 90% NO{sub x} reduction at a space velocity of 3,000 hr{sup -1} when new, which is typical of full-scale installations; after 2,200 hours exposure to flue gas, some of the catalysts appeared to lose NO{sub x} activity. For the fresh commercial catalysts, oxidation of mercury was in the range of 25% to 65% at typical full-scale space velocities. A blank monolith showed no oxidation of mercury under any conditions. All catalysts showed higher mercury oxidation without ammonia, consistent with full-scale measurements. After exposure to flue gas for 2,200 hours, some of the catalysts showed reduced levels of mercury oxidation relative to the initial levels of oxidation. A model of Hg oxidation across SCRs was formulated based on full-scale data. The model took into account the effects of temperature, space velocity, catalyst type and HCl concentration in the flue gas.

Constance Senior

2004-12-31T23:59:59.000Z

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401

Atomistic Simulations of Mass and Thermal Transport in Oxide Nuclear Fuels  

SciTech Connect

In this talk we discuss simulations of the mass and thermal transport in oxide nuclear fuels. Redistribution of fission gases such as Xe is closely coupled to nuclear fuel performance. Most fission gases have low solubility in the fuel matrix, specifically the insolubility is most pronounced for large fission gas atoms such as Xe, and as a result there is a significant driving force for segregation of gas atoms to grain boundaries or dislocations and subsequently for nucleation of gas bubbles at these sinks. The first step of the fission gas redistribution is diffusion of individual gas atoms through the fuel matrix to existing sinks, which is governed by the activation energy for bulk diffusion. Fission gas bubbles are then formed by either separate nucleation events or by filling voids that were nucleated at a prior stage; in both cases their formation and latter growth is coupled to vacancy dynamics and thus linked to the production of vacancies via irradiation or thermal events. In order to better understand bulk Xe behavior (diffusion mechanisms) in UO{sub 2{+-}x} we first calculate the relevant activation energies using density functional theory (DFT) techniques. By analyzing a combination of Xe solution thermodynamics, migration barriers and the interaction of dissolved Xe atoms with U, we demonstrate that Xe diffusion predominantly occurs via a vacancy-mediated mechanism, though other alternatives may exist in high irradiation fields. Since Xe transport is closely related to diffusion of U vacancies, we have also studied the activation energy for this process. In order to explain the low value of 2.4 eV found for U migration from independent damage experiments (not thermal equilibrium) the presence of vacancy clusters must be included in the analysis. Next a continuum transport model for Xe and U is formulated based on the diffusion mechanisms established from DFT. After combining this model with descriptions of the interaction between Xe and grain boundaries derived from separate atomistic calculations, we simulate Xe redistribution for a few simple microstructures using finite element methods (FEM), as implemented in the MOOSE framework from Idaho National Laboratory. Thermal transport together with the power distribution determines the temperature distribution in the fuel rod and it is thus one of the most influential properties on nuclear fuel performance. The fuel thermal conductivity changes as function of time due to microstructure evolution (e.g. fission gas redistribution) and compositional changes. Using molecular dynamics simulations we have studied the impact of different types of grain boundaries and fission gas bubbles on UO{sub 2} thermal conductivity.

Andersson, Anders D. [Los Alamos National Laboratory; Uberuaga, Blas P. [Los Alamos National Laboratory; Du, Shiyu [Los Alamos National Laboratory; Liu, Xiang-Yang [Los Alamos National Laboratory; Nerikar, Pankaj [IBM; Stanek, Christopher R. [Los Alamos National Laboratory; Tonks, Michael [Idaho National Laboratory; Millet, Paul [Idaho National Laboratory; Biner, Bulent [Idaho National Laboratory

2012-06-04T23:59:59.000Z

402

Platinum-CatalyzedOxidations of Organic Compounds by Ferric Sulfate: Use of a Redox Fuel Cell to Mediate Complete Oxidation of  

E-Print Network (OSTI)

and complete oxidation of ethylene glycolto carbon dioxide under mild conditionsusing dioxy- gen operating with ethylene glycol as fuel (5, 10-12). METHODS Materials. Methanol, ethanol, and ethylene catalyst was determined to be 3.3 X mol/g Pt (6.44% dispersion) by alternating titration with hydrogen

Prentiss, Mara

403

A general approach to develop reduced order models for simulation of solid oxide fuel cell stacks  

SciTech Connect

A reduced order modeling approach based on response surface techniques was developed for solid oxide fuel cell stacks. This approach creates a numerical model that can quickly compute desired performance variables of interest for a stack based on its input parameter set. The approach carefully samples the multidimensional design space based on the input parameter ranges, evaluates a detailed stack model at each of the sampled points, and performs regression for selected performance variables of interest to determine the responsive surfaces. After error analysis to ensure that sufficient accuracy is established for the response surfaces, they are then implemented in a calculator module for system-level studies. The benefit of this modeling approach is that it is sufficiently fast for integration with system modeling software and simulation of fuel cell-based power systems while still providing high fidelity information about the internal distributions of key variables. This paper describes the sampling, regression, sensitivity, error, and principal component analyses to identify the applicable methods for simulating a planar fuel cell stack.

Pan, Wenxiao; Bao, Jie; Lo, Chaomei; Lai, Canhai; Agarwal, Khushbu; Koeppel, Brian J.; Khaleel, Mohammad A.

2013-06-15T23:59:59.000Z

404

R and D of Oxide Dispersion Strengthening Steels for High Burn-up Fuel Claddings  

SciTech Connect

Research and development of fuel clad materials for high burn-up operation of light water reactor and super critical water reactor (SCPWR) will be shown with focusing on the effort to overcome the requirements of material performance as the fuel clad. Oxide dispersion strengthening (ODS) steels are well known as a high temperature structural material. Recent irradiation experiments indicated that the steels were quite highly resistant to neutron irradiation embrittlement, showing hardening without accompanying loss of ductility. High Cr ODS steels whose chromium concentration was in the range from 15 to 19 wt% showed high resistance to corrosion in supercritical pressurized water (SCPW). As for the susceptibility to hydrogen embrittlement of ODS steels, the critical hydrogen concentration required to hydrogen embrittlement is ranging 10{approx}12 wppm that is approximately one order of magnitude higher value than that of 9Cr reduced activation ferritic (RAF) steel. In the ODS steels, the fraction of helium desorption by bubble migration mechanism was smaller than that in the RAF steel, indicating that the ODS steels are also resistant to helium He bubble-induced embrittlement. Finally, it is demonstrated that the ODS steels are very promising for the fuel clad material for high burn-up operation of water-cooling reactors. (authors)

Kimura, A.; Cho, H.S.; Lee, J.S.; Kasada, R. [Institute of Advanced Energy, Kyoto University, Gokasho, Uji, Kyoto 611-0011 (Japan); Ukai, S. [Japan Nuclear Cycle Development Institute, Tokai (Japan); Fujiwara, M. [Kobelco, Ltd, Takatsukadai, Nishi-ku, Kobe (Japan)

2004-07-01T23:59:59.000Z

405

Kinematics and thermodynamics across a propagating non-stoichiometric oxidation phase front in spent fuel grains  

SciTech Connect

Spent fuel contains mixtures, alloy and compound, but are dominated by U and O except for some UO{sub 2} fuels with burnable poisons (gadolinia in BWR rods), the other elements evolve during reactor operation from neutron reaction and fission + fission decay events. Due to decay, chemical composition and activity of spent fuel will continue to evolve after removal from reactors. During the time interval with significant radioactivity levels relevant for a geological repository, it is important to develop models for potential chemical responses in spent fuel and potential degradation of repository. One such potential impact is the oxidation of spent fuel, which results in initial phase change of UO{sub 2} lattice to U{sub 4}O{sub 9} and the next phase change is probably to U{sub 3}O{sub 8} although it has not been observed yet below 200C. The U{sub 4}O{sub 9} lattice is nonstoichiometric with a O/U weight ratio at 2.4. Preliminary indications are that the UO{sub 2} has a O/U of 2. 4 at the time just before it transforms into the U{sub 4}O{sub 9} phase. In the oxygen weight gain versus time response, a plateau appears as the O/U approaches 2.4. Part of this plateau is due to geometrical effects of a U{sub 4}O{sub 9} phase change front propagating into UO{sub 2} grain volumes; however, this may indicate a metastable phase change delay kinetics or a diffusional related delay time until the oxygen density can satisfy stoichiometry and energy conditions for phase changes. Experimental data show a front of U{sub 4}O{sub 9} lattice structure propagating into grains of the UO{sub 2} lattice. To describe this spatially inhomogenous oxidation phase transition, as well as the expected U{sub 3}O{sub 8} phase transition from the U{sub 4}O{sub 9} lattice, lattice models are developed and spatially discontinuous kinematic and energetic expressions are derived. 9 refs.

Stout, R.B.; Kansa, E.J.; Wijesinghe, A.M.

1993-09-01T23:59:59.000Z

406

LOW-TEMPERATURE, ANODE-SUPPORTED HIGH POWER DENSITY SOLID OXIDE FUEL CELLS WITH NANOSTRUCTURED ELECTRODES  

SciTech Connect

A simple, approximate analysis of the effect of differing cathode and anode areas on the measurement of cell performance on anode-supported solid oxide fuel cells, wherein the cathode area is smaller than the anode area, is presented. It is shown that the effect of cathode area on cathode polarization, on electrolyte contribution, and on anode resistance, as normalized on the basis of the cathode area, is negligible. There is a small but measurable effect on anode polarization, which results from concentration polarization. Effectively, it is the result of a greater amount of fuel transported to the anode/electrolyte interface in cases wherein the anode area is larger than the cathode area. Experiments were performed on cells made with differing cathode areas and geometries. Cathodic and anodic overpotentials measured using reference electrodes, and the measured ohmic area specific resistances by current interruption, were in good agreement with expectations based on the analysis presented. At 800 C, the maximum power density measured with a cathode area of {approx}1.1 cm{sup 2} was {approx}1.65 W/cm{sup 2} compared to {approx}1.45 W/cm{sup 2} for cathode area of {approx}2 cm{sup 2}, for anode thickness of {approx}1.3 mm, with hydrogen as the fuel and air as the oxidant. At 750 C, the measured maximum power densities were {approx}1.3 W/cm{sup 2} for the cell with cathode area {approx}1.1 cm{sup 2}, and {approx}1.25 W/cm{sup 2} for the cell with cathode area {approx}2 cm{sup 2}.

Anil V. Virkar

2001-06-21T23:59:59.000Z

407

Effect of pre-oxidation and environmental aging on the seal strength of a novel high-temperature solid oxide fuel cell (SOFC) sealing glass with metallic interconnect  

SciTech Connect

A novel high-temperature alkaline-earth silicate sealing glass was developed for solid oxide fuel cell (SOFC) applications. The glass was used to join two ferritic stainless steel coupons for strength evaluation. The steel coupons were pre-oxidized at elevated temperatures to promote thick oxide layers to simulate long-term exposure conditions. In addition, seals to as-received metal coupons were also tested after aging in oxidizing or reducing environments to simulate the actual SOFC environment. Room temperature tensile testing showed strength degradation when using pre-oxidized coupons, and more extensive degradation after aging in air. Fracture surface and microstructural analysis confirmed that the cause of degradation was formation of SrCrO4 at the outer sealing edges exposed to air.

Chou, Y. S.; Stevenson, Jeffry W.; Singh, Prabhakar

2008-09-15T23:59:59.000Z

408

Hydrous pyrolysis/oxidation process for in situ destruction of chlorinated hydrocarbon and fuel hydrocarbon contaminants in water and soil  

DOE Patents (OSTI)

In situ hydrous pyrolysis/oxidation process is useful for in situ degradation of hydrocarbon water and soil contaminants. Fuel hydrocarbons, chlorinated hydrocarbons, polycyclic aromatic hydrocarbons, petroleum distillates and other organic contaminants present in the soil and water are degraded by the process involving hydrous pyrolysis/oxidation into non-toxic products of the degradation. The process uses heat which is distributed through soils and water, optionally combined with oxygen and/or hydrocarbon degradation catalysts, and is particularly useful for remediation of solvent, fuel or other industrially contaminated sites.

Knauss, Kevin G. (Livermore, CA); Copenhaver, Sally C. (Livermore, CA); Aines, Roger D. (Livermore, CA)

2000-01-01T23:59:59.000Z

409

OXIDATION OF MERCURY ACROSS SCR CATALYSTS IN COAL-FIRED POWER PLANTS BURING LOW RANK FUELS  

SciTech Connect

This is the sixth Quarterly Technical Report for DOE Cooperative Agreement No: DE-FC26-03NT41728. The objective of this program is to measure the oxidation of mercury in flue gas across SCR catalyst in a coal-fired power plant burning low rank fuels using a slipstream reactor containing multiple commercial catalysts in parallel. The Electric Power Research Institute (EPRI) and Argillon GmbH are providing co-funding for this program. This program contains multiple tasks and good progress is being made on all fronts. During this quarter, a review of the available data on mercury oxidation across SCR catalysts from small, laboratory-scale experiments, pilot-scale slipstream reactors and full-scale power plants was carried out. Data from small-scale reactors obtained with both simulated flue gas and actual coal combustion flue gas demonstrated the importance of temperature, ammonia, space velocity and chlorine on mercury oxidation across SCR catalyst. SCR catalysts are, under certain circumstances, capable of driving mercury speciation toward the gas-phase equilibrium values at SCR temperatures. Evidence suggests that mercury does not always reach equilibrium at the outlet. There may be other factors that become apparent as more data become available.

Constance Senior

2004-07-30T23:59:59.000Z

410

Effect of Coal Contaminants on Solid Oxide Fuel System Performance and Service Life  

SciTech Connect

The U.S. Department of Energy’s SECA program envisions the development of high-efficiency, low-emission, CO2 sequestration-ready, and fuel-flexible technology to produce electricity from fossil fuels. One such technology is the integrated gasification-solid oxide fuel cell (SOFC) that produces electricity from the gas stream of a coal gasifier. SOFCs have high fuel-to-electricity conversion efficiency, environmental compatibility (low NOx production), and modularity. The primary objective of the Phase I study was to determine the sensitivity of the performance of solid oxide fuel cells to trace level contaminants present in a coal-derived gas stream in the temperature range 700? to 900?C. Laboratory-scale tests were performed with 1-inch diameter solid oxide fuel cells procured from InDec B.V., Netherlands. These cells produce 0.15, 0.27, and 0.35 W/cm2 at 700?, 750?, and 800?C, respectively, in a H2 anode feed and are expected to be stable within 10% of the original performance over a period of 2000 h. A simulated coal-derived gas containing 30.0% CO, 30.6% H2 11.8% CO2, 27.6% H2O was used at a rate of ~100 standard cm3/min to determine the effect of contaminants on the electrical performance of the cells. Alumina or zirconia components were used for the gas manifold to prevent loss of contaminants by reaction with the surfaces of the gas manifold Short-term accelerated tests were conducted with several contaminants including As, P, CH3Cl, HCl, Hg, Sb, and Zn vapors. In these tests, AsH3, PH3, Cd vapor and CH3Cl identified as the potential contaminants that can affect the electrical performance of SOFCs. The effect of some of these contaminants varied with the operating temperature. Cell failure due to contact break inside the anode chamber occurred when the cell was exposed to 10 ppm arsenic vapor at 800?C. The electrical performance of SOFC samples suffered less than 1% in when exposed to contaminants such as HCl(g), Hg(g), and Zn(g), and SbO(g) at levels of 8 ppm and above. AsH3 vapor at 0.5 ppm did not affect the electrical performance of an SOFC sample even after 1000 h at 750?C. In Phase II of the program, long-term tests will be performed with multiple contaminants at a temperature range of 750? to 850?C. These tests will be at contaminant levels typical of coal-derived gas streams that have undergone gas cleanup using Selexol technology. The chemical nature of the contaminant species will be identified at the operating temperature of SOFC and compare them with thermodynamic equilibrium calculations. The results of the testing will be used to recommend the sensitivity limits for SOFC operation and to assess the reduction in the service life of the SOFC for trace level contaminants.

Gopala N. Krishnan, Palitha Jayaweera, Jordi Perez, M. Hornbostel, John. R. Albritton and Raghubir P. Gupta

2007-10-31T23:59:59.000Z

411

High-temperature Chemical Compatibility of As-fabricated TRIGA Fuel and Type 304 Stainless Steel Cladding  

SciTech Connect

Chemical interaction between TRIGA fuel and Type-304 stainless steel cladding at relatively high temperatures is of interest from the point of view of understanding fuel behavior during different TRIGA reactor transient scenarios. Since TRIGA fuel comes into close contact with the cladding during irradiation, there is an opportunity for interdiffusion between the U in the fuel and the Fe in the cladding to form an interaction zone that contains U-Fe phases. Based on the equilibrium U-Fe phase diagram, a eutectic can develop at a composition between the U6Fe and UFe2 phases. This eutectic composition can become a liquid at around 725°C. From the standpoint of safe operation of TRIGA fuel, it is of interest to develop better understanding of how a phase with this composition may develop in irradiated TRIGA fuel at relatively high temperatures. One technique for investigating the development of a eutectic phase at the fuel/cladding interface is to perform out-of-pile diffusion-couple experiments at relatively high temperatures. This information is most relevant for lightly irradiated fuel that just starts to touch the cladding due to fuel swelling. Similar testing using fuel irradiated to different fission densities should be tested in a similar fashion to generate data more relevant to more heavily irradiated fuel. This report describes the results for TRIGA fuel/Type-304 stainless steel diffusion couples that were annealed for one hour at 730 and 800°C. Scanning electron microscopy with energy- and wavelength-dispersive spectroscopy was employed to characterize the fuel/cladding interface for each diffusion couple to look for evidence of any chemical interaction. Overall, negligible fuel/cladding interaction was observed for each diffusion couple.

Dennis D. Keiser, Jr.; Jan-Fong Jue; Eric Woolstenhulme; Kurt Terrani; Glenn A. Moore

2012-09-01T23:59:59.000Z

412

Five percent platinum-tungsten oxide-based electrocatalysts for phosphoric acid fuel cell cathodes  

SciTech Connect

A Pt-tungsten oxide-based electrocatalyst has been fabricated by an inexpensive chemical route for use as an oxygen cathode in 99% phosphoric acid at 180 C. The effect of %WO{sub 3} (wt/wt) on the Pt-tungsten oxide/C-based electrode performance was studied. The electrocatalytic properties for the oxygen reduction reaction (ORR), e.g., exchange current density and mass activity of a 5% Pt-40% WO{sub 3}-based electrode were found to be twice as high as those of 10% Pt, which contains double the amount of platinum. The Tafel slope and specific activity of the two electrodes are similar. It was shown that an increase in its electrochemically active surface area was the only reason for the performance of the 5% Pt-40% WO{sub 3}-based electrode. The electrocatalytic parameters of the 5% Pt-40% WO{sub 3}-based electrode for the ORR were compared to those of the 2% Pt-1% H{sub 2}WO{sub 4}-based electrode.

Savadogo, O.; Beck, P. [Ecole Polytechnique, Montreal, Quebec (Canada). Lab. d`Electrochimie et de Materiaux Energetiques

1996-12-01T23:59:59.000Z

413

Electron Microscopy Study of Novel Ru Doped La0.8Sr0.2CrO3 as Anode Materials for Solid Oxide Fuel Cells (SOFCs)  

E-Print Network (OSTI)

Electron Microscopy Study of Novel Ru Doped La0.8Sr0.2CrO3 as Anode Materials for Solid Oxide Fuel of Materials Science and Engineering, Northwestern University, 2220 Campus Dr. Evanston, IL 60208 Solid Oxide Fuel Cells (SOFCs) have been the center of research activities with the goal of improving energy

Marks, Laurence D.

414

Phase 1 - Evaluation of a Functional Interconnect System for Solid Oxide Fuel Cells  

SciTech Connect

This project is focused on evaluating the suitability of materials and complex multi-materials systems for use as solid oxide fuel cell interconnects. ATI Allegheny Ludlum has generated promising results for interconnect materials which incorporate modified surfaces. Methods for producing these surfaces include cladding, which permits the use of novel materials, and modifications via unique thermomechanical processing, which allows for the modification of materials chemistry. The University of Pittsburgh is assisting in this effort by providing use of their in-place facilities for dual atmosphere testing and ASR measurements, along with substantial work to characterize post-exposure specimens. Carnegie Mellon is testing interconnects for chromia scale spallation resistance using macro-scale and nano-scale indentation tests. Chromia spallation can increase electrical resistance to unacceptable levels and interconnect systems must be developed that will not experience spallation within 40,000 hours at operating temperatures. Spallation is one of three interconnect failure mechanisms, the others being excessive growth of the chromia scale (increasing electrical resistance) and scale evaporation (which can poison the cathode). The goal of indentation fracture testing at Carnegie Mellon is to accelerate the evaluation of new interconnect systems (by inducing spalls at after short exposure times) and to use fracture mechanics to understand mechanisms leading to premature interconnect failure by spallation. Tests include bare alloys from ATI and coated systems from DOE Laboratories and industrial partners, using ATI alloy substrates. West Virginia University is working towards developing a cost-effective material for use as a contact material in the cathode chamber of the SOFC. Currently materials such as platinum are well suited for this purpose, but are cost-prohibitive. For the solid-oxide fuel cell to become a commercial reality it is imperative that lower cost components be developed. Based on the results obtained to date, it appears that sterling silver could be an inexpensive, dependable candidate for use as a contacting material in the cathode chamber of the solid-oxide fuel cell. Although data regarding pure silver samples show a lower rate of thickness reduction, the much lower cost of sterling silver makes it an attractive alternative for use in SOFC operation.

James M. Rakowski

2006-09-30T23:59:59.000Z

415

Extended reaction zone of La0.6Sr0.4Co0.2Fe0.8O3 cathode for solid oxide fuel cell  

SciTech Connect

The oxygen reduction reaction at the cathode of solid oxide fuel cell (SOFC) is a complicated process which involves the interaction of oxygen molecules, electrons, and oxygen ions. Therefore, it can only proceed at locations where gas, electronic conductor, and an oxygen ion conductor meet. Although the extension of the reaction zone beyond the traditional so-called triple-phase-boundary (TPB) is widely accepted for a mixed ionically and electronically conductive cathode, work in this area has yet to reach a consensus on how far the reaction zone can be extended. In this study, anode-supported fuel cells with a variety of LSCF cathode thicknesses were fabricated and tested in two cathode environments, flowing oxygen and flowing air. In flowing oxygen, the cell performance increased with LSCF cathode thickness over the entire range investigated (from 5 to 33 ?m). In flowing air, the cell performance also increased with the LSCF cathode thickness from 5 to 13 ?m, but then remained almost constant with further increase in cathode thickness. In flowing oxygen, since there was no concentration polarization related to oxygen diffusion, the polarization resistance of oxygen reduction decreased with the LSCF cathode thickness because of the increased number of reaction sites. A linear relationship was established between the reciprocal of the polarization resistance and the cathode thickness, which was explained by a model developed for aqueous gas diffusion electrodes.

Lu, Zigui; Hardy, John S.; Templeton, Jared W.; Stevenson, Jeffry W.

2012-01-03T23:59:59.000Z

416

The State-of-the-Art in Sealing Technology for Solid Oxide Fuel Cells  

SciTech Connect

One of the keys to developing viable solid oxide fuel cell (SOFC) systems is to first develop reliable and inexpensive stack sealing technology. Three general approaches are currently being pursued, including: rigid bonded sealing, compressive sealing, and compliant bonded sealing. This review highlights the advantages and limitations of each option, discusses some of the leading concepts, and outlines the future steps that need to be taken in their development. Given the number of different SOFC stack designs under development, the variety of potential applications/conditions in which these systems can be used, and the complexities of stack manufacture, it is likely that no one sealing technique will be suitable for all uses. Therefore continued progress in each general area, as well as the development of new concepts, is critical to the eventual success of SOFC technology.

Weil, K. Scott

2006-08-01T23:59:59.000Z

417

Higher ionic conductive ceria-based electrolytes for solid oxide fuel cells  

Science Journals Connector (OSTI)

Codoping is used to enhance the ionic conductivity of ceria-based electrolytes. Sm 3 + and Nd 3 + were selected as codopants to promote low migration energy paths for oxygen vacancydiffusion thereby increasing the ionic conductivity. Moreover the use of codopants also increases the pre-exponential factor in the Arrhenius relationship thus further improving the ionic conductivity. The ionic conductivity of Sm x Nd x Ce 1 ? 2 x O 2 ? ? solid solutions is measured using electrochemical impedance spectroscopy. It was observed that for Sm 0.075 Nd 0.075 Ce 0.85 O 2 ? ? the grain ionic conductivity was 14.0 × 10 ? 3 S cm ? 1 at 550 ° C which makes it one of the most promising ceria-based electrolytes for intermediate temperature solid oxide fuel cells.

Shobit Omar; Eric D. Wachsman; Juan C. Nino

2007-01-01T23:59:59.000Z

418

Phase-field modeling of three-phase electrode microstructures in solid oxide fuel cells  

Science Journals Connector (OSTI)

A phase-field model for describing three-phase electrode microstructure (i.e. electrode-phase electrolyte-phase and pore-phase) in solid oxide fuel cells is proposed using the diffuse-interface theory. Conserved composition and non-conserved grain orientation order parameters are simultaneously used to describe the coupled phase coarsening and grain growth in the three-phase electrode. The microstructural evolution simulated by the phase-field approach demonstrates the significant dependence of morphological microstructure and output statistic material features on the prescribed kinetic parameters and three-phase volume fractions. The triple-phase boundary fraction is found to have a major degradation in the early evolution.

Qun Li; Linyun Liang; Kirk Gerdes; Long-Qing Chen

2012-01-01T23:59:59.000Z

419

Mechanical properties of solid oxide fuel cell glass-ceramic seal at high temperatures  

SciTech Connect

Mechanical properties of solid oxide fuel cell glass-ceramic seal material, G18, are studied at high temperatures. Samples of G18 are aged for either 4h or 100h, resulting in samples with different crystallinity. Reduced modulus, hardness, and time-dependent behavior are measured by nanoindentation. The nanoindentation is performed at room temperature, 550, 650, and 750°C, using loading rates of 5 mN/s and 25 mN/s. Results show a decrease in reduced modulus with increasing temperature, with significant decrease above the glass transition temperature (Tg). Hardness generally decreases with increasing temperature, with a slight increase before Tg for the 4h aged sample. Dwell tests show that creep increases with increasing temperature, but decrease with further aging.

Milhans, Jacqueline; Li, Dongsheng; Khaleel, Mohammad A.; Sun, Xin; Al-Haik, Marwan; Harris, Adrian; Garmestani, Hamid

2011-04-20T23:59:59.000Z

420

Pulsed D-D Neutron Generator Measurements of HEU Oxide Fuel Pins  

SciTech Connect

Pulsed neutron interrogation measurements have been performed on highly enriched uranium (HEU) oxide fuel pins and depleted uranium (DU) metal using a D-D neutron generator (2x10{sup 6} neutrons-s{sup -1}) and moderated {sup 3}He tubes at the Idaho National Laboratory Power Burst Facility. These measurements demonstrate the ability to distinguish HEU from DU by coincidence counting using a pulsed source. The amount of HEU measured was 8 kg in a sealed 55-gallon drum compared to 31 kg of DU. Neutron events were counted during and after the pulse with the Nuclear Materials Identification System (NMIS) and used to calculate the neutron coincidence time distributions. Passive measurements were also performed for comparison with the pulsed measurements. This paper presents the neutron coincidence time distribution and Feynman variance results from the measurements.

McConchie, Seth; Hausladen, Paul; Mihalczo, John [Oak Ridge National Laboratory, 1 Bethel Valley Road, P.O. Box 2008, Oak Ridge, TN 37831 (United States); Blackburn, Brandon; Chichester, David [Idaho National Laboratory, 2525 North Fremont Avenue, P.O. Box 1625, Idaho Falls, ID 83415 (United States)

2009-03-10T23:59:59.000Z

Note: This page contains sample records for the topic "oxide fuel fabrication" from the National Library of EnergyBeta (NLEBeta).
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421

Pulsed D-D Neutron Generator Measurements of HEU Oxide Fuel Pins  

SciTech Connect

Pulsed neutron interrogation measurements have been performed on highly enriched uranium (HEU) oxide fuel pins and depleted uranium (DU) metal using a D-D neutron generator (2 x 10{sup 6} neutrons-s{sup -1}) and moderated {sup 3}He tubes at the Idaho National Laboratory Power Burst Facility. These measurements demonstrate the ability to distinguish HEU from DU by coincidence counting using a pulsed source. The amount of HEU measured was 8 kg in a sealed 55-gallon drum compared to 31 kg of DU. Neutron events were counted during and after the pulse with the Nuclear Materials Identification System (NMIS) and used to calculate the neutron coincidence time distributions. Passive measurements were also performed for comparison with the pulsed measurements. This paper presents the neutron coincidence distribution and Feynman variance results from the measurements.

McConchie, Seth M [ORNL] [ORNL; Hausladen, Paul [ORNL] [ORNL; Mihalczo, John T [ORNL] [ORNL; Blackburn, Brandon [Idaho National Laboratory (INL)] [Idaho National Laboratory (INL); Chichester, David [Idaho National Laboratory (INL)] [Idaho National Laboratory (INL)

2009-01-01T23:59:59.000Z

422

High Speed, Low Cost Fabrication of Gas Diffusion Electrodes for Membrane Electrode Assemblies - DOE Hydrogen and Fuel Cells Program FY 2012 Annual Progress Report  

NLE Websites -- All DOE Office Websites (Extended Search)

8 8 DOE Hydrogen and Fuel Cells Program FY 2012 Annual Progress Report Emory S. De Castro BASF Fuel Cell, Inc. 39 Veronica Avenue Somerset, NJ 08873 Phone: (732) 545-5100 ext 4114 Email: Emory.DeCastro@BASF.com DOE Managers HQ: Nancy Garland Phone: (202) 586-5673 Email: Nancy.Garland@ee.doe.gov GO: Jesse Adams Phone: (720) 356-1421 Email: Jesse.Adams@go.doe.gov Contract Number: DE-EE0000384 Subcontractor: Dr. Vladimir Gurau Case Western Reserve University, Cleveland, Ohio Project Start Date: July 1, 2009 Project End Date: June 30, 2013 Fiscal Year (FY) 2012 Objectives Reduce cost in fabricating gas diffusion electrodes * through the introduction of high speed coating technology, with a focus on materials used for the high- temperature membrane electrode assemblies (MEAs)

423

Novel Materials for Intermediate-Temperature Solid Oxide Fuel Cells Vincent Wu, University of California, Berkeley, 2011 SURF Fellow  

E-Print Network (OSTI)

of California, Berkeley, 2011 SURF Fellow Advisor: Prof. Meilin Liu Graduate Mentors: Mingfei Liu, Ben Rainwater Introduction The need to develop new cathode materials for intermediate-temperature solid-oxide fuel cells (IT-SOFCs) is driven by the temperature conditions required for IT-SOFC operation. Designing SOFCs to operate at lower

Li, Mo

424

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

Science Journals Connector (OSTI)

...dioxide in the cathode exit stream during...exceptionally stable electrocatalyst that yields...PEM fuel cell cathodes during potential cycling...Ti0.7W0.3O2 electrocatalyst for proton-exchange...Popov BN ( 2009 ) Development of a titanium...oxide-supported platinum electrocatalyst for polymer electrolyte...

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

2014-01-01T23:59:59.000Z

425

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

Science Journals Connector (OSTI)

...carbon support in PEMFC at fuel starvation . ECS...Ti0.7W0.3O2 electrocatalyst for proton-exchange...Popov BN ( 2009 ) Development of a titanium dioxide-supported...oxide-supported platinum electrocatalyst for polymer electrolyte...Mallouk TE ( 2002 ) Development of supported bifunctional...

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

2014-01-01T23:59:59.000Z

426

Gas conversion impedance: A test geometry effect in characterization of solid oxide fuel cell anodes  

SciTech Connect

The appearance of an extra arc in impedance spectra obtained on high performance solid oxide fuel cell (SOFC) anodes is recognized when experiments are conducted in a test setup where the working and reference electrodes are placed in separate atmospheres. A simple continuously stirred tank reactor (CSTR) model is used to illustrate how anodes measured with the reference electrode in an atmosphere separate from the working electrode are subject to an impedance contribution from gas conversion. The gas conversion impedance is split into a resistive and a capacitive part, and the dependences of these parameters on gas composition, temperature, gas flow rate, and rig geometry are quantified. The fuel gas flow rate per unit of anode area is decisive for the resistivity, whereas the capacitance is proportional to the CSTR volume of gas over the anode. The model predictions are compared to actual measurements on Ni/yttria stabilized zirconia cermet anodes for SOFC. The contribution of the gas conversion overpotential to dc current-voltage characteristics is deduced for H{sub 2}/H{sub 2}O and shown to have a slope of RT/2F in a Tafel plot.

Primdahl, S.; Mogensen, M. [Risoe National Lab., Roskilde (Denmark). Materials Research Dept.

1998-07-01T23:59:59.000Z

427

Deep oxidation of glucose in enzymatic fuel cells through a synthetic enzymatic pathway containing a cascade of two thermostable dehydrogenases  

NLE Websites -- All DOE Office Websites (Extended Search)

Deep Deep oxidation of glucose in enzymatic fuel cells through a synthetic enzymatic pathway containing a cascade of two thermostable dehydrogenases Zhiguang Zhu a , Fangfang Sun a , Xiaozhou Zhang a,d , Y.-H. Percival Zhang a,b,c,d,n a Biological Systems Engineering Department, Virginia Polytechnic Institute and State University (Virginia Tech), 210-A Seitz Hall, Blacksburg, Virginia 24061, USA b Institute for Critical Technology and Applied Science (ICTAS), Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061, USA c DOE BioEnergy Science Center (BESC), Oak Ridge, Tennessee 37831, USA d Gate Fuels Inc., 2200 Kraft Drive, Suite 1200B, Blacksburg, VA 24060, USA a r t i c l e i n f o Article history: Received 12 January 2012 Received in revised form 26 March 2012 Accepted 4 April 2012 Keywords: Deep oxidation Enzymatic fuel cell Glucose biobattery Thermoenzyme

428

On the Use of Thermal NF3 as the Fluorination and Oxidation Agent in Treatment of Used Nuclear Fuels  

SciTech Connect

This paper presents results of our investigation on the use of nitrogen trifluoride as the fluorination or fluorination/oxidation agent for use in a process for separating valuable constituents from used nuclear fuels by employing the volatility of many transition metal and actinide fluorides. Nitrogen trifluoride is less chemically and reactively hazardous than the hazardous and aggressive fluorinating agents used to prepare uranium hexafluoride and considered for fluoride volatility based nuclear fuels reprocessing. In addition, nitrogen trifluoride’s less aggressive character may be used to separate the volatile fluorides from used fuel and from themselves based on the fluorination reaction’s temperature sensitivity (thermal tunability) rather than relying on differences in sublimation/boiling temperature and sorbents. Our thermodynamic calculations found that nitrogen trifluoride has the potential to produce volatile fission product and actinide fluorides from candidate oxides and metals. Our simultaneous thermogravimetric and differential thermal analyses found that the oxides of lanthanum, cerium, rhodium, and plutonium fluorinated but did not form volatile fluorides and that depending on temperature volatile fluorides formed from the oxides of niobium, molybdenum, ruthenium, tellurium, uranium, and neptunium. We also demonstrated near-quantitative removal of uranium from plutonium in a mixed oxide.

Scheele, Randall D.; McNamara, Bruce K.; Casella, Andrew M.; Kozelisky, Anne E.

2012-05-01T23:59:59.000Z

429

NOVEL ELECTRODE MATERIALS FOR LOW-TEMPERATURE SOLID-OXIDE FUEL CELLS  

SciTech Connect

Composite electrodes consisting of silver and bismuth vanadates exhibit remarkable catalytic activity for oxygen reduction at 500-550 C and greatly reduce the cathode-electrolyte (doped ceria) resistances of low temperature SOFCs, down to about 0.53 {Omega}cm{sup 2} at 500 C and 0.21 {Omega}cm{sup 2} at 550 C. The observed power densities of 231, 332, and 443 mWcm{sup -2} at 500, 525 and 550 C, respectively, make it possible to operate SOFCs at temperatures about 500 C. Using in situ potential dependent FTIR emission spectroscopy, we have found evidence for two, possibly three distinct di-oxygen species present on the electrode surface. We have successfully identified which surface oxygen species is present under a particular electrical or chemical condition and have been able to deduce the reaction mechanisms. This technique will be used to probe the gas-solid interactions at or near the TPB and on the surfaces of mixed-conducting electrodes in an effort to understand the molecular processes relevant to the intrinsic catalytic activity. Broad spectral features are assigned to the polarization-induced changes in the optical properties of the electrode surface layer. The ability of producing vastly different microstructures and morphologies of the very same material is critical to the fabrication of functionally graded electrodes for solid-state electrochemical devices, such as SOFCs and lithium batteries. By carefully adjusting deposition parameters of combustion CVD, we have successfully produced oxide nano-powders with the size of 30 {approx} 200 nm. Porous films with various microstructures and morphologies are also deposited on several substrates by systematic adjustment of deposition parameters. Symmetrical cells were fabricated by depositing cathode materials on both sides of GDC electrolytes.

X. Lu; C. Xia; Y. Liu; W. Rauch; M. Liu

2002-12-01T23:59:59.000Z

430

Performance of Anode-Supported Solid Oxide Fuel Cell with Thin Bi-Layer Electrolyte by Pulsed Laser Deposition  

SciTech Connect

Anode-supported yttria stabilized zirconia (YSZ)/samaria doped ceria (SDC) bi-layer electrolytes with uniform thickness and high density were fabricated by pulsed laser deposition at 1000 degrees C. Fuel cells with such bi-layer electrolytes were fabricated and tested, yielding open circuit voltages from 0.94 to 1.0 V at 600-700 degrees C. Power densities from 0.4 to 1.0 W cm{sup -2} at 0.7 V were achieved in air at temperatures of 600-700 degrees C. Cell performance was improved in flowing oxygen, with an estimated peak power density of over 2 W cm{sup -2} at 650 degrees C, assuming the same overall resistance over the entire range of current density. The high cell performance was attributed to the very low ohmic resistance of the fuel cell, owing to the small thickness of the electrolyte. Stable performance was also demonstrated in that the voltage of the fuel cell showed very little change at a constant current density of 1 A cm{sup -2} during more than 400 hours of operation at 650 degrees C in flowing oxygen. SEM analysis of the fuel cell after testing showed that the bi-layer electrolyte had retained its chemical and mechanical integrity.

Lu, Zigui; Hardy, John S.; Templeton, Jared W.; Stevenson, Jeffry W.; Fisher, Daniel; Wu, Naijuan; Ignatiev, Alex

2012-07-15T23:59:59.000Z

431

ZERO EMISSION POWER PLANTS USING SOLID OXIDE FUEL CELLS AND OXYGEN TRANSPORT MEMBRANES  

SciTech Connect

Over 16,700 hours of operational experience was gained for the Oxygen Transport Membrane (OTM) elements of the proposed SOFC/OTM zero-emission power generation concept. It was repeatedly demonstrated that OTMs with no additional oxidation catalysts were able to completely oxidize the remaining depleted fuel in a simulated SOFC anode exhaust at an O{sub 2} flux that met initial targets. In such cases, neither residual CO nor H{sub 2} were detected to the limits of the gas chromatograph (<10 ppm). Dried OTM afterburner exhaust streams contained up to 99.5% CO{sub 2}. Oxygen flux through modified OTMs was double or even triple that of the standard OTMs used for the majority of testing purposes. Both the standard and modified membranes in laboratory-scale and demonstration-sized formats exhibited stable performance over extended periods (2300 to 3500 hours or 3 to 5 months). Reactor contaminants, were determined to negatively impact OTM performance stability. A method of preventing OTM performance degradation was developed and proven to be effective. Information concerning OTM and seal reliability over extended periods and through various chemical and thermal shocks and cycles was also obtained. These findings were used to develop several conceptual designs for pilot (10 kWe) and commercial-scale (250 kWe) SOFC/OTM zero emission power generation systems.

G. Maxwell Christie; Troy M. Raybold

2003-06-10T23:59:59.000Z

432

Creep analysis of solid oxide fuel cell with bonded compliant seal design  

Science Journals Connector (OSTI)

Abstract Solid oxide fuel cell (SOFC) requires good sealant because it works in harsh conditions (high temperature, thermal cycle, oxidative and reducing gas environments). Bonded compliant seal (BCS) is a new sealing method for planar SOFC. It uses a thin foil metal to bond the window frame and cell, achieving the seal between window frame and cell. At high temperature, a comprehensive evaluation of its creep strength is essential for the adoption of BCS design. In order to characterize the creep behavior, the creep induced by thermal stresses in SOFC with BCS design is simulated by finite element method. The results show that the foil is compressed and large thermal stresses are generated. The initial peak thermal stress is located in the thin foil because the foil acts as a spring stores the thermal stresses by elastic and plastic deformation in itself. Serving at high temperature, initial thermal displacement is partially recovered because of the creep relaxation, which becomes a new discovered advantage for BCS design. It predicts that the failures are likely to happen in the middle of the cell edge and BNi-2 filler metal, because the maximum residual displacement and creep strain are located.

Wenchun Jiang; Yucai Zhang; Yun Luo; J.M. Gong; S.T. Tu

2013-01-01T23:59:59.000Z

433

Combined Theoretical and Experimental Analysis of Processes Determining Cathode Performance in Solid Oxide Fuel Cells  

SciTech Connect

Solid oxide fuel cells (SOFC) are under intensive investigation since the 1980’s as these devices open the way for ecologically clean direct conversion of the chemical energy into electricity, avoiding the efficiency limitation by Carnot’s cycle for thermochemical conversion. However, the practical development of SOFC faces a number of unresolved fundamental problems, in particular concerning the kinetics of the electrode reactions, especially oxygen reduction reaction. We review recent experimental and theoretical achievements in the current understanding of the cathode performance by exploring and comparing mostly three materials: (La,Sr)MnO3 (LSM), (La,Sr)(Co,Fe)O3 (LSCF) and (Ba,Sr)(Co,Fe)O3 (BSCF). Special attention is paid to a critical evaluation of advantages and disadvantages of BSCF, which shows the best cathode kinetics known so far for oxides. We demonstrate that it is the combined experimental and theoretical analysis of all major elementary steps of the oxygen reduction reaction which allows us to predict the rate determining steps for a given material under specific operational conditions and thus control and improve SOFC performance.

Kukla, Maija M.; Kotomin, Eugene Alexej; Merkle, R.; Mastrikov, Yuri; Maier, J.

2013-02-11T23:59:59.000Z

434

The LMFBR fuel-design environment for endurance testing, primarily of oxide fuel elements with local faults  

SciTech Connect

The U.S. Department of Energy LMFBR Lines-of-Assurance are briefly stated and local faults are given perspective with an historical review and definition to help define the constraints of LMFBR fuel-element designs. Local-fault-propagation (fuel-element-failure propagation and blockage propagation) perceptions are reviewed. Fuel pin designs and major LMFBR parameters affecting pin performance are summarized. The interpretation of failed-fuel data is aided by a discussion of the effects of nonprototypicalities. The fuel-pin endurances expected in the United States, USSR, France, UK, Japan, and West Germany are outlined. Finally, fuel-failure detection and location by delayed-neutron and gaseous-fission product monitors are briefly discussed to better realize the operational limits.

Warinner, D.K.

1983-07-01T23:59:59.000Z

435

Extended Two Dimensional Nanotube and Nanowire Surfaces as Fuel Cell Catalysts  

E-Print Network (OSTI)

transportation field: solid oxide fuel cells require highto solid oxide, alkaline, and direct alcohol fuel cells.

Alia, Shaun Michael

2011-01-01T23:59:59.000Z

436

Determination of Radial Power Profiles in Thorium-Plutonium Mixed Oxide Fuel Pellets.  

E-Print Network (OSTI)

??To be able to license fuel for use in commercial nuclear reactors its thermomechanical behavior needs to be well known. For this, fuel performance codes… (more)

fredriksson, patrik

2014-01-01T23:59:59.000Z

437

LMFBR fuel component costs  

SciTech Connect

A significant portion of the cost of fabricating LMFBR fuels is in the non-fuel components such as fuel pin cladding, fuel assembly ducts and end fittings. The contribution of these to fuel fabrication costs, based on FFTF experience and extrapolated to large LMFBR fuel loadings, is discussed. The extrapolation considers the expected effects of LMFBR development programs in progress on non-fuel component costs.

Epperson, E.M.; Borisch, R.R.; Rice, L.H.

1981-10-29T23:59:59.000Z

438

Advanced Materials for Reversible Solid Oxide Fuel Cell (RSOFC), Dual Mode Operation with Low Degradation  

Energy.gov (U.S. Department of Energy (DOE))

Presented at the Department of Energy Fuel Cell Projects Kickoff Meeting, September 1 – October 1, 2009

439

Fuels  

NLE Websites -- All DOE Office Websites (Extended Search)

Goals > Fuels Goals > Fuels XMAT for nuclear fuels XMAT is ideally suited to explore all of the radiation processes experienced by nuclear fuels.The high energy, heavy ion accleration capability (e.g., 250 MeV U) can produce bulk damage deep in the sample, achieving neutron type depths (~10 microns), beyond the range of surface sputtering effects. The APS X-rays are well matched to the ion beams, and are able to probe individual grains at similar penetrations depths. Damage rates to 25 displacements per atom per hour (DPA/hr), and doses >2500 DPA can be achieved. MORE» Fuels in LWRs are subjected to ~1 DPA per day High burn-up fuel can experience >2000 DPA. Traditional reactor tests by neutron irradiation require 3 years in a reactor and 1 year cool down. Conventional accelerators (>1 MeV/ion) are limited to <200-400 DPAs, and

440

Effects of Tungsten Oxide Addition on the Electrochemical Performance of Nanoscale Tantalum Oxide-Based Electrocatalysts for Proton Exchange Membrane PEM Fuel Cells  

SciTech Connect

In the present study, the properties of a series of non-platinum based nanoscale tantalum oxide/tungsten oxide-carbon composite catalysts was investigated for potential use in catalyzing the oxygen reduction reaction (ORR) on the cathode side of a PEM fuel cell membrane electrode assembly. Electrochemical performance was measured using a half-cell test set up with a rotating disc electrode and compared with a commercial platinum-on-carbon (Pt/C) catalyst. Overall, all of the oxide-based composite catalysts exhibit high ORR on-set potentials, comparable to that of the baseline Pt/C catalyst. The addition of tungsten oxide as a dopant to tantalum oxide greatly improved mass specific current density. Maximum performance was achieved with a catalyst containing 32 mol% of tungsten oxide, which exhibited a mass specific current density ~8% that of the Pt/C catalyst at 0.6 V vs. the normal hydrogen electrode (NHE) and ~35% that of the Pt/C catalyst at 0.2 V vs. NHE. Results from X-ray photoelectron spectroscopy analysis indicated that the tungsten cations in the composite catalysts exist in the +6 oxidation state, while the tantalum displays an average valence of +5, suggesting that the addition of tungsten likely creates an oxygen excess in the tantalum oxide structure that influences its oxygen absorption kinetics. When the 32mol% tungsten doped catalyst loading on the working electrode was increased to five times that of the original loading (which was equivalent to that of the baseline Pt/C catalyst), the area specific current density improved four fold, achieving an area specific current density ~35% that of the Pt/C catalyst at 0.6 V vs. NHE.

Oh, Tak Keun; Kim, Jin Yong; Shin, Yongsoon; Engelhard, Mark H.; Weil, K. Scott

2011-08-01T23:59:59.000Z

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441

The effect of low-temperature oxidation on the fuel and produced oil during in situ combustion  

SciTech Connect

Combustion tube experiments using 10.2{degrees} API crude oil were performed, in which a different sample matrix was used in each run. Three matrix types were tested: sand, sand and clay, and sand and sand fines. As a result of the low fuel concentration, low-temperature oxidation (LTO) was observed in the run where the matrix consisted of sand only. High-temperature oxidation (HTO) was observed in runs where either clay or sand fines were part of the matrix. Ignition was not obtained in the LTO run, which had a reaction front temperature of only 350{degrees}C (662{degrees}F), compared to a combustion front temperature of 500{degrees}C (932{degrees}F) for the HTO runs. From elemental analysis, the fuel during the LTO run was determined to be an oxygenated hydrocarbon with an atomic oxygen-carbon ratio of 0.3.

Mamora, D.D. [Texas A& M Univ., College Station, TX (United States); Brigham, W.E. [Stanford Univ., CA (United States)

1995-02-01T23:59:59.000Z

442

Performance of solid oxide fuel cells operaated with coal syngas provided directly from a gasification process  

SciTech Connect

Solid oxide fuel cells (SOFCs) are being developed for integrated gasification power plants that generate electricity from coal at 50% efficiency. The interaction of trace metals in coal syngas with Ni-based SOFC anodes is being investigated through thermodynamic analyses and in laboratory experiments, but test data from direct coal syngas exposure are sparsely available. This effort evaluates the significance of performance losses associated with exposure to direct coal syngas. Specimen are operated in a unique mobile test skid that is deployed to the research gasifier at NCCC in Wilsonville, AL. The test skid interfaces with a gasifier slipstream to deliver hot syngas to a parallel array of twelve SOFCs. During the 500 h test period, all twelve cells are monitored for performance at four current densities. Degradation is attributed to syngas exposure and trace material attack on the anode structure that is accelerated at increasing current densities. Cells that are operated at 0 and 125 mA cm{sup 2} degrade at 9.1 and 10.7% per 1000 h, respectively, while cells operated at 250 and 375 mA cm{sup 2} degrade at 18.9 and 16.2% per 1000 h, respectively. Spectroscopic analysis of the anodes showed carbon, sulfur, and phosphorus deposits; no secondary Ni-metal phases were found.

Hackett, G.; Gerdes, K.; Song, X.; Chen, Y.; Shutthanandan, V.; Englehard, M.; Zhu, Z.; Thevuthasan, S.; Gemmen, R.

2012-01-01T23:59:59.000Z

443

Enhancement of the inherent self-protection of the fast sodium reactor cores with oxide fuel  

SciTech Connect

With the development and research into the generation IV fast sodium reactors, great attention is paid to the enhancement of the core inherent self-protection characteristics. One of the problems dealt here is connected with the reduction of the reactivity margin so that the control rods running should not result in the core overheating and melting. In this paper we consider the possibilities of improving the core of BN-1200 with oxide fuel by a known method of introducing an axial fertile layer into the core. But unlike earlier studies this paper looks at the possibility of using such a layer not only for improving breeding, but also for reducing sodium void reactivity effect (SVRE). This proposed improvement of the BN-1200 core does not solve the problem of strong interference in control and protection system (CPS) rods of BN-1200, but they reduce significantly the reactivity margin for burn-up compensation. This helps compensate all the reactivity balances in the improved core configurations without violating constraints on SVRE value.

Eliseev, V.A.; Malisheva, I.V.; Matveev, V.I.; Egorov, A.V.; Maslov, P.A. [SSC RF - IPPE, Obninsk, Kaluga region (Russian Federation)

2013-07-01T23:59:59.000Z

444

Simulation of creep and damage in the bonded compliant seal of planar solid oxide fuel cell  

Science Journals Connector (OSTI)

Abstract Planar solid oxide fuel cell (SOFC) operates at high temperature and requires a good creep strength to ensure the structure integrity. This paper presents a creep and damage analysis of a bonded compliant seal (BCS) structure of a planar SOFC considering the effect of as-bonded residual stress and thermal stress, as well as the effect of filler metal and foil thickness. A modified continuum creep-damage model is used in the finite element simulation. It demonstrates that the BCS structure meets the requirement of the long-term operation at the high temperature of 600 °C with an appropriate braze bonding process. The results show that the failure location is not in the region of maximum creep deformation due to the effect of high level multi-axial stress which drastically decreases the multi-axial ductility. Reasonably reducing the thickness of filler metal and foil can decrease the damage of the BCS structure. Based on the consideration of creep and damage, it is proposed that the thickness of filler metal and foil should not exceed 0.1 and 0.05 mm, respectively.

Yu-Cai Zhang; Wenchun Jiang; Shan-Tung Tu; Jian-Feng Wen

2014-01-01T23:59:59.000Z

445

Global Failure Criteria for Positive/Electrolyte/Negative Structure of Planar Solid Oxide Fuel Cell  

SciTech Connect

Due to mismatch of the coefficients of thermal expansion of various layers in the positive/electrolyte/negative (PEN) structures of solid oxide fuel cells (SOFC), thermal stresses and warpage on the PEN are unavoidable due to the temperature changes from the stress-free sintering temperature to room temperature during the PEN manufacturing process. In the meantime, additional mechanical stresses will also be created by mechanical flattening during the stack assembly process. In order to ensure the structural integrity of the cell and stack of SOFC, it is necessary to develop failure criteria for SOFC PEN structures based on the initial flaws occurred during cell sintering and stack assembly. In this paper, the global relationship between the critical energy release rate and critical curvature and maximum displacement of the warped cells caused by the temperature changes as well as mechanical flattening process is established so that possible failure of SOFC PEN structures may be predicted deterministically by the measurement of the curvature and displacement of the warped cells.

Liu, Wenning N.; Sun, Xin; Khaleel, Mohammad A.; Qu, Jianmin

2009-07-15T23:59:59.000Z

446

Lanthanum manganite-based air electrode for solid oxide fuel cells  

DOE Patents (OSTI)

An air electrode material for a solid oxide fuel cell is disclosed. The electrode material is based on lanthanum manganite having a perovskite-like crystal structure ABO.sub.3. The A-site of the air electrode material preferably comprises La, Ca, Ce and at least one lanthanide selected from Sm, Gd, Dy, Er, Y and Nd. The B-site of the electrode material comprises Mn with substantially no dopants. The ratio of A:B is preferably slightly above 1. A preferred air electrode composition is of the formula La.sub.w Ca.sub.x Ln.sub.y Ce.sub.z MnO.sub.3, wherein Ln comprises at least one lanthanide selected from Sm, Gd, Dy, Er, Y and Nd, w is from about 0.55 to about 0.56, x is from about 0.255 to about 0.265, y is from about 0.175 to about 0.185, and z is from about 0.005 to about 0.02. The air electrode material possesses advantageous chemical and electrical properties as well as favorable thermal expansion and thermal cycle shrinkage characteristics.

Ruka, Roswell J. (Pittsburgh, PA); Kuo, Lewis (Monroeville, PA); Li, Baozhen (Essex Junction, VT)

1999-01-01T23:59:59.000Z

447

Lanthanum manganite-based air electrode for solid oxide fuel cells  

DOE Patents (OSTI)

An air electrode material for a solid oxide fuel cell is disclosed. The electrode material is based on lanthanum manganite having a perovskite-like crystal structure ABO[sub 3]. The A-site of the air electrode material preferably comprises La, Ca, Ce and at least one lanthanide selected from Sm, Gd, Dy, Er, Y and Nd. The B-site of the electrode material comprises Mn with substantially no dopants. The ratio of A:B is preferably slightly above 1. A preferred air electrode composition is of the formula La[sub w]Ca[sub x]Ln[sub y]Ce[sub z]MnO[sub 3], wherein Ln comprises at least one lanthanide selected from Sm, Gd, Dy, Er, Y and Nd, w is from about 0.55 to about 0.56, x is from about 0.255 to about 0.265, y is from about 0.175 to about 0.185, and z is from about 0.005 to about 0.02. The air electrode material possesses advantageous chemical and electrical properties as well as favorable thermal expansion and thermal cycle shrinkage characteristics. 10 figs.

Ruka, R.J.; Kuo, L.; Li, B.

1999-06-29T23:59:59.000Z

448

Selective production of hydrogen for fuel cells via oxidative steam reforming of methanol over CuZnAl(Zr)-oxide catalysts  

Science Journals Connector (OSTI)

Fuel cell powered vehicles using hydrogen (H2) as a fuel are currently being developed in an effort to mitigate the emissions of green house gases such as CO2, NOx, and hydrocarbons. The H2 fuel is extracted from methanol onboard a vehicle by steam reforming of methanol (SRM) reaction. A considerable amount of CO is produced as a by-product, which is a poison to the Pt anode of the fuel cell. Very recently, we have demonstrated that a combined SRM and partial oxidation of methanol (POM), which we labeled as “oxidative steam reforming of methanol (OSRM)” reaction is more efficient for the selective production of H2 relatively at a lower temperature of around 230°C over CuZnAl(Zr)-oxide catalysts derived from hydroxycarbonate precursors containing hydrotalcite (HT)-like layered double hydroxides (LDHs)/aurichalcite phases. There are several operating parameters such as catalyst composition, reaction temperature, O2/CH3OH and H2O/CH3OH molar ratios and methanol injection rate that are need to be optimized in order to produce H2 suitable for fuelling a fuel cell. In the present study, we have investigated the effect of these variable parameters on the catalytic performance over a series of CuZnAl- and CuZnAlZr-oxide catalysts. Our study indicated that among the CuZn-based catalysts, those containing Zr were the most active. The optimum O2/CH3OH and H2O/CH3OH molar ratios should be in the ranges 0.20–0.30 and 1.3–1.6, respectively, in order to achieve a better catalytic performance. Studies of the effect of methanol contact time on the catalytic performance over a Zr-containing catalyst revealed that the OSRM reaction proceeds through the formation of formaldehyde intermediate. CO was prod