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Sample records for mixed oxide fuel plant

  1. Mixed oxide fuel development

    SciTech Connect

    Leggett, R.D.; Omberg, R.P.

    1987-05-08

    This paper describes the success of the ongoing mixed-oxide fuel development program in the United States aimed at qualifying an economical fuel system for liquid metal cooled reactors. This development has been the cornerstone of the US program for the past 20 years and has proceeded in a deliberate and highly disciplined fashion with high emphasis on fuel reliability and operational safety as major features of an economical fuel system. The program progresses from feature testing in EBR-II to qualifying full size components in FFTF under fully prototypic conditions to establish a basis for extending allowable lifetimes. The development program started with the one year (300 EFPD) core, which is the FFTF driver fuel, continued with the demonstration of a two year (600 EFPD) core and is presently evaluating a three year (900 EFPD) fuel system. All three of these systems, consistent with other LMR fuel programs around the world, use fuel pellets gas bonded to a cladding tube that is assembled into a bundle and fitted into a wrapper tube or duct for ease of insertion into a core. The materials of construction progressed from austenitic CW 316 SS to lower swelling austenitic D9 to non swelling ferritic/martensitic HT9. 6 figs., 2 tabs.

  2. Decommissioning of a mixed oxide fuel fabrication plant at Winfrith Technolgy Centre

    SciTech Connect

    Pengelly, M.G.A.

    1994-01-01

    The Alpha Materials Laboratory (Building A52) at Winfrith contained a mixed oxide fuel fabrication plant which had a capability of producing 10 te/yr of pelleted/compacted fuel and was in operation from 1962 until 1980, when the requirement for this type of fuel in the UK diminished, and the plant became surplus to requirements. A program to develop decommissioning techniques for plutonium plants was started in 1983, addressing the following aspects of alpha plant decommissioning: (1) Re-usable containment systems, (2) Strippable coating technology, (3) Mobile air filtration plant, (4) Size reduction primarily using cold cutting, (5) techniques, (6) Waste packing, and (7) Alpha plant decommissioning methodology. The technology developed has been used to safely and efficiently decommission radioactive plant and equipment including Pu contaminated glove boxes. (63 glove boxes to date) The technology has been widely adopted in the United Kingdom and elsewhere. This paper outlines the general strategies adopted and techniques used for glove box decommissioning in building A52.

  3. Mixed Oxide Fresh Fuel Package Auxiliary Equipment

    SciTech Connect

    Yapuncich, F.; Ross, A.; Clark, R.H.; Ammerman, D.

    2008-07-01

    The United States Department of Energy's National Nuclear Security Administration (NNSA) is overseeing the construction the Mixed Oxide (MOX) Fuel Fabrication Facility (MFFF) on the Savannah River Site. The new facility, being constructed by NNSA's contractor Shaw AREVA MOX Services, will fabricate fuel assemblies utilizing surplus plutonium as feedstock. The fuel will be used in designated commercial nuclear reactors. The MOX Fresh Fuel Package (MFFP), which has recently been licensed by the Nuclear Regulatory Commission (NRC) as a type B package (USA/9295/B(U)F-96), will be utilized to transport the fabricated fuel assemblies from the MFFF to the nuclear reactors. It was necessary to develop auxiliary equipment that would be able to efficiently handle the high precision fuel assemblies. Also, the physical constraints of the MFFF and the nuclear power plants require that the equipment be capable of loading and unloading the fuel assemblies both vertically and horizontally. The ability to reconfigure the load/unload evolution builds in a large degree of flexibility for the MFFP for the handling of many types of both fuel and non fuel payloads. The design and analysis met various technical specifications including dynamic and static seismic criteria. The fabrication was completed by three major fabrication facilities within the United States. The testing was conducted by Sandia National Laboratories. The unique design specifications and successful testing sequences will be discussed. (authors)

  4. Critical experiments with mixed oxide fuel

    SciTech Connect

    Harris, D.R.

    1997-06-01

    This paper very briefly outlines technical considerations in performing critical experiments on weapons-grade plutonium mixed oxide fuel assemblies. The experiments proposed would use weapons-grade plutonium and Er{sub 2}O{sub 3} at various dissolved boron levels, and for specific fuel assemblies such as the ABBCE fuel assembly with five large water holes. Technical considerations described include the core, the measurements, safety, security, radiological matters, and licensing. It is concluded that the experiments are feasible at the Rensselaer Polytechnic Institute Reactor Critical Facility. 9 refs.

  5. Analytical chemistry methods for mixed oxide fuel, March 1985

    SciTech Connect

    Not Available

    1985-03-01

    This standard provides analytical chemistry methods for the analysis of materials used to produce mixed oxide fuel. These materials are ceramic fuel and insulator pellets and the plutonium and uranium oxides and nitrates used to fabricate these pellets.

  6. Chemical and Radiochemical Composition of Thermally Stabilized Plutonium Oxide from the Plutonium Finishing Plant Considered as Alternate Feedstock for the Mixed Oxide Fuel Fabrication Facility

    SciTech Connect

    Tingey, Joel M.; Jones, Susan A.

    2005-07-01

    Eighteen plutonium oxide samples originating from the Plutonium Finishing Plant (PFP) on the Hanford Site were analyzed to provide additional data on the suitability of PFP thermally stabilized plutonium oxides and Rocky Flats oxides as alternate feedstock to the Mixed Oxide Fuel Fabrication Facility (MFFF). Radiochemical and chemical analyses were performed on fusions, acid leaches, and water leaches of these 18 samples. The results from these destructive analyses were compared with nondestructive analyses (NDA) performed at PFP and the acceptance criteria for the alternate feedstock. The plutonium oxide materials considered as alternate feedstock at Hanford originated from several different sources including Rocky Flats oxide, scrap from the Remote Mechanical C-Line (RMC) and the Plutonium Reclamation Facility (PRF), and materials from other plutonium conversion processes at Hanford. These materials were received at PFP as metals, oxides, and solutions. All of the material considered as alternate feedstock was converted to PuO2 and thermally stabilized by heating the PuO2 powder at 950 C in an oxidizing environment. The two samples from solutions were converted to PuO2 by precipitation with Mg(OH)2. The 18 plutonium oxide samples were grouped into four categories based on their origin. The Rocky Flats oxide was divided into two categories, low- and high-chloride Rocky Flats oxides. The other two categories were PRF/RMC scrap oxides, which included scrap from both process lines and oxides produced from solutions. The two solution samples came from samples that were being tested at Pacific Northwest National Laboratory because all of the plutonium oxide from solutions at PFP had already been processed and placed in 3013 containers. These samples originated at the PFP and are from plutonium nitrate product and double-pass filtrate solutions after they had been thermally stabilized. The other 16 samples originated from thermal stabilization batches before canning at

  7. Microstructure and thermophysical characterization of mixed oxide fuels

    SciTech Connect

    Freibert, Franz J; Salich, Tarik A; Schwartz, Daniel S; Hampel, Fred G; Mitchell, Jeremy N; Davis, Charles C; Neuman, Angelique D; Willson, Steve P; Dunwoody, John T

    2009-01-01

    Pre-irradiated thermodynamic and microstructural properties of nuclear fuels form the necessary set of data against which to gauge fuel performance and irradiation damage evolution. This paper summarizes recent efforts in mixed-oxide and minor actinide-bearing mixed-oxide ceramic fuels fabrication and characterization at Los Alamos National Laboratory. Ceramic fuels (U{sub 1-x-y-z}u{sub x}Am{sub y}Np{sub z})O{sub 2} fabricated in the compositional ranges of 0.19 {le} x {le} 0.3 Pu, 0 {le} y {le} 0.05 Am, and O {le} z {le} O.03 Np exhibited a uniform crystalline face-centered cubic phase with an average grain size of 14{micro}m; however, electron microprobe analysis revealed segregation of NpO{sub 2} in minor actinide-bearing fuels. Immersion density and porosity analysis demonstrated an average density of 92.4% theoretical for mixed-oxide fuels and an average density of 89.5 % theoretical density for minor actinide-bearing mixed-oxide fuels. Examined fuels exhibited mean thermal expansion value of 12.56 x 10{sup -6} C{sup -1} for temperature range (100 C < T < 1500 C) and ambient temperature Young's modulus and Poisson's ratio of 169 GPa and of 0.327, respectively. Internal dissipation as determined from mechanical resonances of these ceramic fuels has shown promise as a tool to gauge microstructural integrity and to interrogate fundamental properties.

  8. Experience in PWR and BWR mixed-oxide fuel management

    SciTech Connect

    Schlosser, G.J.; Krebs, W.; Urban, P. )

    1993-04-01

    Germany has adopted the strategy of a closed fuel cycle using reprocessing and recycling. The central issue today is plutonium recycling by the use of U-Pu mixed oxide (MOX) in pressurized water reactors (PWRs) and boiling water reactors (BWRs). The design of MOX fuel assemblies and fuel management in MOX-containing cores are strongly influenced by the nuclear properties of the plutonium isotopes. Optimized MOX fuel assembly designs for PWRs currently use up to three types of MOX fuel rods having different plutonium contents with natural uranium or uranium tailings as carrier material but without burnable absorbers. The MOX fuel assembly designs for BWRs use four to six rod types with different plutonium contents and Gd[sub 2]O[sub 3]/UO[sub 2] burnable absorber rods. Both the PWR and the BWR designs attain good burnup equivalence and compatibility with uranium fuel assemblies. High flexibility exists in the loading schemes relative to the position and number of MOX fuel assemblies in the reloads and in the core as a whole. The Siemens experience with MOX fuel assemblies is based on the insertion of 318 MOX fuel assemblies in eight PWRs and 168 in BWRs and pressurized heavy water reactors so far. The primary operating results include information on the cycle length, power distribution, reactivity coefficients, and control rod worth of cores containing MOX fuel assemblies.

  9. Fabrication of non-fertile and evolutionary mixed oxide fuels

    SciTech Connect

    Ramsey, K.B.; Chidester, D.M.

    1996-10-01

    Non-fertile and evolutionary mixed oxide (EMOX) fuels for light water reactors have been fabricated using the solid-state reaction method. Specifically, the non-fertile fuel form fabricated for this study was a PuO{sub 2}-ZrO{sub 2}-CaO-Er{sub 2}O{sub 3}composition. Weapons-grade plutonium served as the source of PuO{sub 2}. The non-fertile fuel offers the key advantage of the {open_quotes}deep burn{close_quotes} capability for a once-through cycle. The non-fertile fuel achieves this performance through the absence of uranium, which breeds plutonium, in the fuel composition. An EMOX fuel form with a composition of PuO{sub 2}-UO{sub 2}-ZrO{sub 2}-CaO was also fabricated using weapons-grade plutonium and depleted uranium. The EMOX fuel concept allows for greater plutonium destruction as compared to standard MOX fuel and provides a licensing path forward towards eventual implementation of non-fertile fuels in light water reactors. This paper summarizes the ongoing activities and past accomplishments for the fabrication of non-fertile and EMOX fuel pellets. 2 figs.

  10. Antineutrino monitoring of burning mixed oxide plutonium fuels

    NASA Astrophysics Data System (ADS)

    Hayes, A. C.; Trellue, H. R.; Nieto, Michael Martin; Wilson, W. B.

    2012-02-01

    Background: Antineutrino monitoring of reactors is an enhanced nuclear safeguard that is being explored by several international groups. A key question is whether such a scheme could be used to verify the destruction of plutonium loaded in a reactor as mixed oxide (MOX) fuel.Purpose: To explore the effectiveness of antineutrino monitoring for the purposes of nuclear accountability and safeguarding of MOX plutonium, we examine the magnitude and temporal variation in the antineutrino signals expected for different loadings of MOX fuels.Methods: Reactor burn simulations are carried out for four different MOX fuel loadings and the antineutrino signals as a function of fuel burnup are computed and compared.Results: The antineutrino signals from reactor-grade and weapons-grade MOX are shown to be distinct from those from burning low enriched uranium, and this signal difference increases as the MOX plutonium fraction of the reactor core increases.Conclusion: Antineutrino monitoring could be used to verify the destruction of plutonium in reactors, although verifying the grade of the plutonium being burned is found to be more challenging.

  11. Experience making mixed oxide fuel with plutonium from dismantled weapons

    SciTech Connect

    Blair, H.T.; Ramsey, K.B.

    1995-12-31

    Mixed depleted UO{sub 2} and PuO{sub 2} (MOX) pellets prototypic of fuel proposed for use in commercial power reactors were made with plutonium recovered from dismantled weapons. We characterized plutonium dioxide powders that were produced at the Los Alamos and Lawrence Livermore National Laboratories (LANL and LLNL) using various methods to recover the plutonium from weapons parts and to convert It to oxide. The gallium content of the PUO{sub 2} prepared at LANL was the same as in the weapon alloy while the content of that prepared at LLNL was less. The MOX was prepared with a five weight percent plutonium content. We tested various MOX powders milling methods to improve homogeneity and found vibratory milling superior to ball milling. The sintering behavior of pellets made with the PuO{sub 2} from the two laboratories was similar. We evaluated the effects of gallium and of erbium and gadolinium, that are added to the MOX fuel as deplorable neutron absorbers, on the pellet fabrication process and an the sintered pellets. The gallium content of the sintered pellets was <10 ppm, suggesting that the gallium will not be an issue in the reactor, but that it will be an Issue in the operation of the fuel fabrication processing equipment unless it is removed from the PuO{sub 2} before it is blended with the UO{sub 2}.

  12. 76 FR 65544 - Standard Format and Content of License Applications for Mixed Oxide Fuel Fabrication Facilities

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-21

    ... issuance of the guide (74 FR 36780). The comment period closed on September 21, 2009. The staff's responses... COMMISSION Standard Format and Content of License Applications for Mixed Oxide Fuel Fabrication Facilities... Format and Content of License Applications for Mixed Oxide Fuel Fabrication Facilities.'' This...

  13. Redox state of plutonium in irradiated mixed oxide fuels

    NASA Astrophysics Data System (ADS)

    Degueldre, C.; Pin, S.; Poonoosamy, J.; Kulik, D. A.

    2014-03-01

    Nowadays, MOX fuels are used in about 20 nuclear power plants around the world. After irradiation, plutonium co-exists with uranium oxide. Due to the redox sensitive nature of UO2 other plutonium oxides than PuO2 potentially present in the fuel may interact with the matrix. The aim of this study is to determine which plutonium species are present in heterogeneous and homogeneous MOX. The results provided by X-ray Absorption Near Edge Spectroscopy (XANES) for non-irradiated as well as irradiated (center and periphery) homogeneous MOX fuel were published earlier and are completed by Extended X-ray Fine Structure (EXAFS) analysis in this work. The EXAFS signals have been extracted using the ATHENA code and the analyses were carried using EXCURE98 as performed earlier for an analogous element. EXAFS shows that plutonium redox state remains tetravalent in the solid solution and that the minor fraction of trivalent Pu must be below 10%. Independently, the study of homogeneous MOX was also approached by thermodynamics of solid solution of (U,Pu)O2. Such solid solutions were modeled using the Gibbs Energy Minimisation (GEM)-Selektor code (developed at LES, NES, PSI) supported by the literature data on such solid solutions. A comparative study was performed showing which plutonium oxides in their respective mole fractions are more likely to occur in (U,Pu)O2. In the modeling, these oxides were set as ideal and non-ideal solid solutions, as well as separate pure phases. Pu exists mainly as PuO2 in the case of separate phases, but can exist under its reduced forms, PuO1.61 and PuO1.5 in minor fraction i.e. ~15% in ideal solid solution (unlikely) and ~10% in non-ideal solid solution (likely) and at temperature around 1300 K. This combined thermodynamic and EXAFS studies confirm independently the results obtained so far by Pu XANES for the same MOX samples.

  14. Thermodynamic calculations of oxygen self-diffusion in mixed-oxide nuclear fuels

    DOE PAGES

    Parfitt, David C.; Cooper, Michael William; Rushton, Michael J.D.; Christopoulos, S. R.; Fitzpatrick, M. E.; Chroneos, A.

    2016-07-29

    Mixed-oxide fuels containing uranium with thorium and/or plutonium may play an important part in future nuclear fuel cycles. There are, however, significantly less data available for these materials than conventional uranium dioxide fuel. In the present study, we employ molecular dynamics calculations to simulate the elastic properties and thermal expansivity of a range of mixed oxide compositions. These are then used to support equations of state and oxygen self-diffusion models to provide a self-consistent prediction of the behaviour of these mixed oxide fuels at arbitrary compositions.

  15. Molten carbonate fuel cell cathode with mixed oxide coating

    DOEpatents

    Hilmi, Abdelkader; Yuh, Chao-Yi

    2013-05-07

    A molten carbonate fuel cell cathode having a cathode body and a coating of a mixed oxygen ion conductor materials. The mixed oxygen ion conductor materials are formed from ceria or doped ceria, such as gadolinium doped ceria or yttrium doped ceria. The coating is deposited on the cathode body using a sol-gel process, which utilizes as precursors organometallic compounds, organic and inorganic salts, hydroxides or alkoxides and which uses as the solvent water, organic solvent or a mixture of same.

  16. Nanoparticle cerium oxide and mixed cerium oxides for improved fuel cell lifetime

    NASA Astrophysics Data System (ADS)

    Stewart, Stephen Michael

    While there is a rich body of literature concerning of properties of bulk cerium oxide and cerium cations in solution, the discussion has been inappropriately applied to nanoscale cerium oxide resulting in many unexpected or unexplained results. In particular, there is very limited understanding about the properties of cerium oxide and its potential use as a radical scavenger, and how the catalytic properties of cerium oxide change as the particle size approaches the nanoscale. For example, the involvement of Ce+4 and Ce+3 cations in reactions such as hydrogen peroxide decomposition have been investigated for both cerium cations and bulk cerium oxide. However, while both are assumed to decompose hydrogen peroxide through the same mechanism, whereby Ce+4 is involved in peroxide decomposition while Ce +3 is involved in radical scavenging, there has been very little done to address how the selectivity and activity of these reactions are affected by changing the majority cation population, as cerium cations in solution are predominantly in the +3 oxidation state while cerium cations are predominantly in the +4 oxidation state in cerium oxide. This matter is further complicated in cerium oxide nanoparticles where the surface concentration of Ce +3 cations is increased due to particle curvature effects. Due to the potential of controlling the surface cerium oxidation state using particle size and using this control to change the catalytic properties, this project investigated the effect of particle size and composition and the activity and selectivity of cerium oxide nanoparticles, and has served to expand the understanding of the properties of pure and mixed nanoparticle cerium oxide. This work explains the metric developed for measuring the catalytic properties of pure and mixed cerium oxide nanoparticles, which is also good at predicting the immediate and long-term behavior of nanoparticles in hydrogen fuel cells. This work also directly demonstrates praseodymium

  17. Mixed fuel strategy for carbon deposition mitigation in solid oxide fuel cells at intermediate temperatures.

    PubMed

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

    2014-06-17

    In this study, we propose and experimentally verified that methane and formic acid mixed fuel can be employed to sustain solid oxide fuel cells (SOFCs) to deliver high power outputs at intermediate temperatures and simultaneously reduce the coke formation over the anode catalyst. In this SOFC system, methane itself was one part of the fuel, but it also played as the carrier gas to deliver the formic acid to reach the anode chamber. On the other hand, the products from the thermal decomposition of formic acid helped to reduce the carbon deposition from methane cracking. In order to clarify the reaction pathways for carbon formation and elimination occurring in the anode chamber during the SOFC operation, O2-TPO and SEM analysis were carried out together with the theoretical calculation. Electrochemical tests demonstrated that stable and high power output at an intermediate temperature range was well-maintained with a peak power density of 1061 mW cm(-2) at 750 °C. With the synergic functions provided by the mixed fuel, the SOFC was running for 3 days without any sign of cell performance decay. In sharp contrast, fuelled by pure methane and tested at similar conditions, the SOFC immediately failed after running for only 30 min due to significant carbon deposition. This work opens a new way for SOFC to conquer the annoying problem of carbon deposition just by properly selecting the fuel components to realize their synergic effects.

  18. Mixed fuel strategy for carbon deposition mitigation in solid oxide fuel cells at intermediate temperatures.

    PubMed

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

    2014-06-17

    In this study, we propose and experimentally verified that methane and formic acid mixed fuel can be employed to sustain solid oxide fuel cells (SOFCs) to deliver high power outputs at intermediate temperatures and simultaneously reduce the coke formation over the anode catalyst. In this SOFC system, methane itself was one part of the fuel, but it also played as the carrier gas to deliver the formic acid to reach the anode chamber. On the other hand, the products from the thermal decomposition of formic acid helped to reduce the carbon deposition from methane cracking. In order to clarify the reaction pathways for carbon formation and elimination occurring in the anode chamber during the SOFC operation, O2-TPO and SEM analysis were carried out together with the theoretical calculation. Electrochemical tests demonstrated that stable and high power output at an intermediate temperature range was well-maintained with a peak power density of 1061 mW cm(-2) at 750 °C. With the synergic functions provided by the mixed fuel, the SOFC was running for 3 days without any sign of cell performance decay. In sharp contrast, fuelled by pure methane and tested at similar conditions, the SOFC immediately failed after running for only 30 min due to significant carbon deposition. This work opens a new way for SOFC to conquer the annoying problem of carbon deposition just by properly selecting the fuel components to realize their synergic effects. PMID:24856957

  19. Interatomic potentials for mixed oxide and advanced nuclear fuels

    SciTech Connect

    Tiwary, Pratyush; Walle, Axel van de; Jeon, Byoungseon; Groenbech-Jensen, Niels

    2011-03-01

    We extend our recently developed interatomic potentials for UO{sub 2} to the fuel system (U,Pu,Np)O{sub 2}. We do so by fitting against an extensive database of ab initio results as well as to experimental measurements. The applicability of these interactions to a variety of mixed environments beyond the fitting domain is also assessed. The employed formalism makes these potentials applicable across all interatomic distances without the need for any ambiguous splining to the well-established short-range Ziegler-Biersack-Littmark universal pair potential. We therefore expect these to be reliable potentials for carrying out damage simulations (and molecular dynamics simulations in general) in nuclear fuels of varying compositions for all relevant atomic collision energies.

  20. Decay Heat Calculations for PWR and BWR Assemblies Fueled with Uranium and Plutonium Mixed Oxide Fuel using SCALE

    SciTech Connect

    Ade, Brian J; Gauld, Ian C

    2011-10-01

    In currently operating commercial nuclear power plants (NPP), there are two main types of nuclear fuel, low enriched uranium (LEU) fuel, and mixed-oxide uranium-plutonium (MOX) fuel. The LEU fuel is made of pure uranium dioxide (UO{sub 2} or UOX) and has been the fuel of choice in commercial light water reactors (LWRs) for a number of years. Naturally occurring uranium contains a mixture of different uranium isotopes, primarily, {sup 235}U and {sup 238}U. {sup 235}U is a fissile isotope, and will readily undergo a fission reaction upon interaction with a thermal neutron. {sup 235}U has an isotopic concentration of 0.71% in naturally occurring uranium. For most reactors to maintain a fission chain reaction, the natural isotopic concentration of {sup 235}U must be increased (enriched) to a level greater than 0.71%. Modern nuclear reactor fuel assemblies contain a number of fuel pins potentially having different {sup 235}U enrichments varying from {approx}2.0% to {approx}5% enriched in {sup 235}U. Currently in the United States (US), all commercial nuclear power plants use UO{sub 2} fuel. In the rest of the world, UO{sub 2} fuel is still commonly used, but MOX fuel is also used in a number of reactors. MOX fuel contains a mixture of both UO{sub 2} and PuO{sub 2}. Because the plutonium provides the fissile content of the fuel, the uranium used in MOX is either natural or depleted uranium. PuO{sub 2} is added to effectively replace the fissile content of {sup 235}U so that the level of fissile content is sufficiently high to maintain the chain reaction in an LWR. Both reactor-grade and weapons-grade plutonium contains a number of fissile and non-fissile plutonium isotopes, with the fraction of fissile and non-fissile plutonium isotopes being dependent on the source of the plutonium. While only RG plutonium is currently used in MOX, there is the possibility that WG plutonium from dismantled weapons will be used to make MOX for use in US reactors. Reactor-grade plutonium

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

    SciTech Connect

    Menlove, Howard O; Lee, Sang - Yoon

    2009-01-01

    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.

  2. Effect of standing transverse acoustic oscillations on fuel-oxidant mixing in cylindrical combustion chambers

    NASA Technical Reports Server (NTRS)

    Mickelsen, William R

    1957-01-01

    Vapor fuel-oxidant mixing is analyzed for standing transverse acoustic fields simulating those existing in screeching or screaming combustors. The additional mixing due to the acoustic field is shown to be a function of sound pressure and frequency, stream velocity, and turbulence. The effects of these parameters are shown graphically for a realistic range of combustor conditions. The fuel-oxidant ratio at various combustor stations is shown to have a cyclic fluctuation which is in phase with the pressure fluctuations. Possible mechanisms contributing to screech and scream are discussed.

  3. Efficient powder blending in support of plutonium conversion for mixed oxide fuel

    SciTech Connect

    Dennison, D.K.; Brucker, J.P.; Martinez, H.E.

    1999-06-07

    This paper describes a unique system that is used to mix and blend multiple batches of plutonium oxide powder of various consistencies into an equivalent number of identical and homogeneously mixed batches. This system is being designed and built to support the Advanced Recovery and Integrated Extraction System (ARIES) at the Los Alamos TA-55 Plutonium Facility. The ARIES program demonstrates dismantlement of nuclear pits, retrieval of the plutonium components, and conversion of the plutonium into an oxide for eventual use in mixed oxide (MOX) fuel for nuclear reactors. The purpose of this powder blending work is to assure that ARIES oxide is converted into an unclassified homogeneous mixture and that consistent feed material is available for MOX fuel assembly. This blending system is being assembled in a selected glovebox a TA-55 using an LANL designed split/combine apparatus, a commercial Turbula blending unit, and several additional supporting hardware components.

  4. Microstructural Modeling of Thermal Conductivity of High Burn-up Mixed Oxide Fuel

    SciTech Connect

    Melissa Teague; Michael Tonks; Stephen Novascone; Steven Hayes

    2014-01-01

    Predicting the thermal conductivity of oxide fuels as a function of burn-up and temperature is fundamental to the efficient and safe operation of nuclear reactors. However, modeling the thermal conductivity of fuel is greatly complicated by the radially inhomogeneous nature of irradiated fuel in both composition and microstructure. In this work, radially and temperature-dependent models for effective thermal conductivity were developed utilizing optical micrographs of high burn-up mixed oxide fuel. The micrographs were employed to create finite element meshes with the OOF2 software. The meshes were then used to calculate the effective thermal conductivity of the microstructures using the BISON fuel performance code. The new thermal conductivity models were used to calculate thermal profiles at end of life for the fuel pellets. These results were compared to thermal conductivity models from the literature, and comparison between the new finite element-based thermal conductivity model and the Duriez–Lucuta model was favorable.

  5. Microstructural modeling of thermal conductivity of high burn-up mixed oxide fuel

    NASA Astrophysics Data System (ADS)

    Teague, Melissa; Tonks, Michael; Novascone, Stephen; Hayes, Steven

    2014-01-01

    Predicting the thermal conductivity of oxide fuels as a function of burn-up and temperature is fundamental to the efficient and safe operation of nuclear reactors. However, modeling the thermal conductivity of fuel is greatly complicated by the radially inhomogeneous nature of irradiated fuel in both composition and microstructure. In this work, radially and temperature-dependent models for effective thermal conductivity were developed utilizing optical micrographs of high burn-up mixed oxide fuel. The micrographs were employed to create finite element meshes with the OOF2 software. The meshes were then used to calculate the effective thermal conductivity of the microstructures using the BISON [1] fuel performance code. The new thermal conductivity models were used to calculate thermal profiles at end of life for the fuel pellets. These results were compared to thermal conductivity models from the literature, and comparison between the new finite element-based thermal conductivity model and the Duriez-Lucuta model was favorable.

  6. Simulated physical inventory verification exercise at a mixed-oxide fuel fabrication facility

    SciTech Connect

    Reilly, D.; Augustson, R.

    1985-01-01

    A physical inventory verification (PIV) was simulated at a mixed-oxide fuel fabrication facility. Safeguards inspectors from the International Atomic Energy Agency (IAEA) conducted the PIV exercise to test inspection procedures under ''realistic but relaxed'' conditions. Nondestructive assay instrumentation was used to verify the plutonium content of samples covering the range of material types from input powders to final fuel assemblies. This paper describes the activities included in the exercise and discusses the results obtained. 5 refs., 1 fig., 6 tabs.

  7. Radial plutonium redistribution in mixed-oxide fuel. [LMFBR

    SciTech Connect

    Lawrence, L.A.; Schwinkendorf, K.N.; Karnesky, R.A.

    1981-10-01

    Alpha autoradiographs from all HEDL fuel pin metallography samples are evaluated and catalogued according to different plutonium distribution patterns. The data base is analyzed for effects of fabrication and operating parameters on redistribution.

  8. Modeling of thermo-mechanical and irradiation behavior of mixed oxide fuel for sodium fast reactors

    NASA Astrophysics Data System (ADS)

    Karahan, Aydın; Buongiorno, Jacopo

    2010-01-01

    An engineering code to model the irradiation behavior of UO2-PuO2 mixed oxide fuel pins in sodium-cooled fast reactors was developed. The code was named fuel engineering and structural analysis tool (FEAST-OXIDE). FEAST-OXIDE has several modules working in coupled form with an explicit numerical algorithm. These modules describe: (1) fission gas release and swelling, (2) fuel chemistry and restructuring, (3) temperature distribution, (4) fuel-clad chemical interaction and (5) fuel-clad mechanical analysis. Given the fuel pin geometry, composition and irradiation history, FEAST-OXIDE can analyze fuel and cladding thermo-mechanical behavior at both steady-state and design-basis transient scenarios. The code was written in FORTRAN-90 program language. The mechanical analysis module implements the LIFE algorithm. Fission gas release and swelling behavior is described by the OGRES and NEFIG models. However, the original OGRES model has been extended to include the effects of joint oxide gain (JOG) formation on fission gas release and swelling. A detailed fuel chemistry model has been included to describe the cesium radial migration and JOG formation, oxygen and plutonium radial distribution and the axial migration of cesium. The fuel restructuring model includes the effects of as-fabricated porosity migration, irradiation-induced fuel densification, grain growth, hot pressing and fuel cracking and relocation. Finally, a kinetics model is included to predict the clad wastage formation. FEAST-OXIDE predictions have been compared to the available FFTF, EBR-II and JOYO databases, as well as the LIFE-4 code predictions. The agreement was found to be satisfactory for steady-state and slow-ramp over-power accidents.

  9. Impact of conversion to mixed-oxide fuels on reactor structural components

    SciTech Connect

    Yahr, G.T.

    1997-04-01

    The use of mixed-oxide (MOX) fuel to replace conventional uranium fuel in commercial light-water power reactors will result in an increase in the neutron flux. The impact of the higher flux on the structural integrity of reactor structural components must be evaluated. This report briefly reviews the effects of radiation on the mechanical properties of metals. Aging degradation studies and reactor operating experience provide a basis for determining the areas where conversion to MOX fuels has the potential to impact the structural integrity of reactor components.

  10. Note: Application of CR-39 plastic nuclear track detectors for quality assurance of mixed oxide fuel pellets

    SciTech Connect

    Kodaira, S. Kurano, M.; Hosogane, T.; Ishikawa, F.; Kageyama, T.; Sato, M.; Kayano, M.; Yasuda, N.

    2015-05-15

    A CR-39 plastic nuclear track detector was used for quality assurance of mixed oxide fuel pellets for next-generation nuclear power plants. Plutonium (Pu) spot sizes and concentrations in the pellets are significant parameters for safe use in the plants. We developed an automatic Pu detection system based on dense α-radiation tracks in the CR-39 detectors. This system would greatly improve image processing time and measurement accuracy, and will be a powerful tool for rapid pellet quality assurance screening.

  11. Note: Application of CR-39 plastic nuclear track detectors for quality assurance of mixed oxide fuel pellets.

    PubMed

    Kodaira, S; Kurano, M; Hosogane, T; Ishikawa, F; Kageyama, T; Sato, M; Kayano, M; Yasuda, N

    2015-05-01

    A CR-39 plastic nuclear track detector was used for quality assurance of mixed oxide fuel pellets for next-generation nuclear power plants. Plutonium (Pu) spot sizes and concentrations in the pellets are significant parameters for safe use in the plants. We developed an automatic Pu detection system based on dense α-radiation tracks in the CR-39 detectors. This system would greatly improve image processing time and measurement accuracy, and will be a powerful tool for rapid pellet quality assurance screening.

  12. Note: Application of CR-39 plastic nuclear track detectors for quality assurance of mixed oxide fuel pellets.

    PubMed

    Kodaira, S; Kurano, M; Hosogane, T; Ishikawa, F; Kageyama, T; Sato, M; Kayano, M; Yasuda, N

    2015-05-01

    A CR-39 plastic nuclear track detector was used for quality assurance of mixed oxide fuel pellets for next-generation nuclear power plants. Plutonium (Pu) spot sizes and concentrations in the pellets are significant parameters for safe use in the plants. We developed an automatic Pu detection system based on dense α-radiation tracks in the CR-39 detectors. This system would greatly improve image processing time and measurement accuracy, and will be a powerful tool for rapid pellet quality assurance screening. PMID:26026564

  13. Note: Application of CR-39 plastic nuclear track detectors for quality assurance of mixed oxide fuel pellets

    NASA Astrophysics Data System (ADS)

    Kodaira, S.; Kurano, M.; Hosogane, T.; Ishikawa, F.; Kageyama, T.; Sato, M.; Kayano, M.; Yasuda, N.

    2015-05-01

    A CR-39 plastic nuclear track detector was used for quality assurance of mixed oxide fuel pellets for next-generation nuclear power plants. Plutonium (Pu) spot sizes and concentrations in the pellets are significant parameters for safe use in the plants. We developed an automatic Pu detection system based on dense α-radiation tracks in the CR-39 detectors. This system would greatly improve image processing time and measurement accuracy, and will be a powerful tool for rapid pellet quality assurance screening.

  14. Mixed oxide fuels testing in the advanced test reactor to support plutonium disposition

    SciTech Connect

    Ryskamp, J.M.; Sterbentz, J.W.; Chang, G.S.

    1995-09-01

    An intense worldwide effort is now under way to find means of reducing the stockpile of weapons-grade plutonium. One of the most attractive solutions would be to use WGPu as fuel in existing light water reactors (LWRs) in the form of mixed oxide (MOX) fuel - i.e., plutonia (PUO{sub 2}) mixed with urania (UO{sub 2}). Before U.S. reactors could be used for this purpose, their operating licenses would have to be amended. Numerous technical issues must be resolved before LWR operating licenses can be amended to allow the use of MOX fuel. These issues include the following: (1) MOX fuel fabrication process verification, (2) Whether and how to use burnable poisons to depress MOX fuel initial reactivity, which is higher than that of urania, (3) The effects of WGPu isotopic composition, (4) The feasibility of loading MOX fuel with plutonia content up to 7% by weight, (5) The effects of americium and gallium in WGPu, (6) Fission gas release from MOX fuel pellets made from WGPu, (7) Fuel/cladding gap closure, (8) The effects of power cycling and off-normal events on fuel integrity, (9) Development of radial distributions of burnup and fission products, (10) Power spiking near the interfaces of MOX and urania fuel assemblies, and (11) Fuel performance code validation. We have performed calculations to show that the use of hafnium shrouds can produce spectrum adjustments that will bring the flux spectrum in ATR test loops into a good approximation to the spectrum anticipated in a commercial LWR containing MOX fuel while allowing operation of the test fuel assemblies near their optimum values of linear heat generation rate. The ATR would be a nearly ideal test bed for developing data needed to support applications to license LWRs for operation with MOX fuel made from weapons-grade plutonium. The requirements for planning and implementing a test program in the ATR have been identified.

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

    SciTech Connect

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

    1995-12-31

    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.

  16. 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

    Evans, Louise G; Croft, Stephen; Swinhoe, Martyn T; Tobin, S. J.; Menlove, H. O.; Schear, M. A.; Worrall, Andrew

    2011-01-13

    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.

  17. 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

    Evans, Louise G; Croft, Stephen; Swinhoe, Martyn T; Tobin, S. J.; Boyer, B. D.; Menlove, H. O.; Schear, M. A.; Worrall, Andrew

    2010-11-24

    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.

  18. A simple model for neutron radiography of uranium-plutonium mixed oxide fuel pins

    NASA Astrophysics Data System (ADS)

    Panakkal, J. P.; Ghosh, J. K.

    1988-04-01

    Neutron radiography has been used for monitoring plutonium enrichment in uranium-plutonium mixed oxide fuel pellets inside welded nuclear fuel pins by correlating the optical density of radiographs at the centre of the pellets and plutonium enrichment. Optical density data corresponding to different thickness of the pellets starting from the centre towards the periphery was generated by microdensitometer scanning of neutron radiographs of the experimental fuel pins. An attempt has been made to correlate the optical density at points corresponding to different thickness segments of the pellets and thermal neutron interaction probability (product of the total macroscopic neutron cross section and the distance traversed by the neutrons). Based on the experimental data generated, a simple model for transmission of neutrons through nuclear fuel pins has been evolved. Using this model, it is possible to predict the optical density of plutonium bearing fuel pins containing pellets of different composition or diameter in neutron radiographic investigations.

  19. The underwater coincidence counter (UWCC) for plutonium measurements in mixed oxide fuels

    SciTech Connect

    Eccleston, G.W.; Menlove, H.O.; Abhold, M.; Baker, M.; Pecos, J.

    1998-12-31

    The use of fresh uranium-plutonium mixed oxide (MOX) fuel in light-water reactors (LWR) is increasing in Europe and Japan and it is necessary to verify the plutonium content in the fuel for international safeguards purposes. The UWCC is a new instrument that has been designed to operate underwater and nondestructively measure the plutonium in unirradiated MOX fuel assemblies. The UWCC can be quickly configured to measure either boiling-water reactor (BWR) or pressurized-water reactor (PWR) fuel assemblies. The plutonium loading per unit length is measured using the UWCC to precisions of less than 1% in a measurement time of 2 to 3 minutes. Initial calibrations of the UWCC were completed on measurements of MOX fuel in Mol, Belgium. The MCNP-REN Monte Carlo simulation code is being benchmarked to the calibration measurements to allow accurate simulations for extended calibrations of the UWCC.

  20. Thorium-based mixed oxide fuel in a pressurized water reactor: A feasibility analysis with MCNP

    NASA Astrophysics Data System (ADS)

    Tucker, Lucas Powelson

    This dissertation investigates techniques for spent fuel monitoring, and assesses the feasibility of using a thorium-based mixed oxide fuel in a conventional pressurized water reactor for plutonium disposition. Both non-paralyzing and paralyzing dead-time calculations were performed for the Portable Spectroscopic Fast Neutron Probe (N-Probe), which can be used for spent fuel interrogation. Also, a Canberra 3He neutron detector's dead-time was estimated using a combination of subcritical assembly measurements and MCNP simulations. Next, a multitude of fission products were identified as candidates for burnup and spent fuel analysis of irradiated mixed oxide fuel. The best isotopes for these applications were identified by investigating half-life, photon energy, fission yield, branching ratios, production modes, thermal neutron absorption cross section and fuel matrix diffusivity. 132I and 97Nb were identified as good candidates for MOX fuel on-line burnup analysis. In the second, and most important, part of this work, the feasibility of utilizing ThMOX fuel in a pressurized water reactor (PWR) was first examined under steady-state, beginning of life conditions. Using a three-dimensional MCNP model of a Westinghouse-type 17x17 PWR, several fuel compositions and configurations of a one-third ThMOX core were compared to a 100% UO2 core. A blanket-type arrangement of 5.5 wt% PuO2 was determined to be the best candidate for further analysis. Next, the safety of the ThMOX configuration was evaluated through three cycles of burnup at several using the following metrics: axial and radial nuclear hot channel factors, moderator and fuel temperature coefficients, delayed neutron fraction, and shutdown margin. Additionally, the performance of the ThMOX configuration was assessed by tracking cycle length, plutonium destroyed, and fission product poison concentration.

  1. Calculation of parameters for inspection planning and evaluation: mixed-oxide fuel fabrication facilities

    SciTech Connect

    Reardon, P.T.; Mullen, M.F.

    1982-08-01

    As part of Task C.35 (Calculation of Parameters for Inspection Planning and Evaluation) of the US Program of Technical Assistance to IAEA Safeguards, Pacific Northwest Laboratory has performed some quantitative analyses of IAEA inspection activities for mixed-oxide fuel fabrication facilities. There were four distinct efforts involved in this task. These were as follows: show the effect on a material balance verification of using two variables measurement methods in some strata; perform additional calculations for the reference facility described in STR-89; modify the INSPECT computer programs to be used as an after-inspection analysis tool, as well as a preinspection planning tool; provide written comments and explantations of text and graphs of the first draft of STR-89, Safeguards Considerations for Mixed-Oxide Fuel Element Fabrication Facilities, by W. Bahm, T. Shea, and D. Tolchenkov, System Studies Section, IAEA.

  2. The underwater coincidence counter for plutonium measurements in mixed-oxide fuel assemblies manual

    SciTech Connect

    G. W. Eccleston; H. O. Menlove; M. Abhold; M. Baker; J. Pecos

    1999-05-01

    This manual describes the Underwater Coincidence Counter (UWCC) that has been designed for the measurement of plutonium in mixed-oxide (MOX) fuel assemblies prior to irradiation. The UWCC uses high-efficiency {sup 3}He neutron detectors to measure the spontaneous-fission and induced-fission rates in the fuel assembly. Measurements can be made on MOX fuel assemblies in air or underwater. The neutron counting rate is analyzed for singles, doubles, and triples time correlations to determine the {sup 240}Pu effective mass per unit length of the fuel assembly. The system can verify the plutonium loading per unit length to a precision of less than 1% in a measurement time of 2 to 3 minutes. System design, components, performance tests, and operational characteristics are described in this manual.

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

    SciTech Connect

    Morreale, A. C.; Ball, M. R.; Novog, D. R.; Luxat, J. C.

    2012-07-01

    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)

  4. Evaluation of Co-precipitation Processes for the Synthesis of Mixed-Oxide Fuel Feedstock Materials

    SciTech Connect

    Collins, Emory D; Voit, Stewart L; Vedder, Raymond James

    2011-06-01

    The focus of this report is the evaluation of various co-precipitation processes for use in the synthesis of mixed oxide feedstock powders for the Ceramic Fuels Technology Area within the Fuels Cycle R&D (FCR&D) Program's Advanced Fuels Campaign. The evaluation will include a comparison with standard mechanical mixing of dry powders and as well as other co-conversion methods. The end result will be the down selection of a preferred sequence of co-precipitation process for the preparation of nuclear fuel feedstock materials to be used for comparison with other feedstock preparation methods. A review of the literature was done to identify potential nitrate-to-oxide co-conversion processes which have been applied to mixtures of uranium and plutonium to achieve recycle fuel homogeneity. Recent studies have begun to study the options for co-converting all of the plutonium and neptunium recovered from used nuclear fuels, together with appropriate portions of recovered uranium to produce the desired mixed oxide recycle fuel. The addition of recycled uranium will help reduce the safeguard attractiveness level and improve proliferation resistance of the recycled fuel. The inclusion of neptunium is primarily driven by its chemical similarity to plutonium, thus enabling a simple quick path to recycle. For recycle fuel to thermal-spectrum light water reactors (LWRs), the uranium concentration can be {approx}90% (wt.), and for fast spectrum reactors, the uranium concentration can typically exceed 70% (wt.). However, some of the co-conversion/recycle fuel fabrication processes being developed utilize a two-step process to reach the desired uranium concentration. In these processes, a 50-50 'master-mix' MOX powder is produced by the co-conversion process, and the uranium concentration is adjusted to the desired level for MOX fuel recycle by powder blending (milling) the 'master-mix' with depleted uranium oxide. In general, parameters that must be controlled for co

  5. Development of ORIGEN Libraries for Mixed Oxide (MOX) Fuel Assembly Designs

    DOE PAGES

    Mertyurek, Ugur; Gauld, Ian C.

    2015-12-24

    In this research, ORIGEN cross section libraries for reactor-grade mixed oxide (MOX) fuel assembly designs have been developed to provide fast and accurate depletion calculations to predict nuclide inventories, radiation sources and thermal decay heat information needed in safety evaluations and safeguards verification measurements of spent nuclear fuel. These ORIGEN libraries are generated using two-dimensional lattice physics assembly models that include enrichment zoning and cross section data based on ENDF/B-VII.0 evaluations. Using the SCALE depletion sequence, burnup-dependent cross sections are created for selected commercial reactor assembly designs and a representative range of reactor operating conditions, fuel enrichments, and fuel burnup.more » The burnup dependent cross sections are then interpolated to provide problem-dependent cross sections for ORIGEN, avoiding the need for time-consuming lattice physics calculations. The ORIGEN libraries for MOX assembly designs are validated against destructive radiochemical assay measurements of MOX fuel from the MALIBU international experimental program. This program included measurements of MOX fuel from a 15 × 15 pressurized water reactor assembly and a 9 × 9 boiling water reactor assembly. The ORIGEN MOX libraries are also compared against detailed assembly calculations from the Phase IV-B numerical MOX fuel burnup credit benchmark coordinated by the Nuclear Energy Agency within the Organization for Economic Cooperation and Development. Finally, the nuclide compositions calculated by ORIGEN using the MOX libraries are shown to be in good agreement with other physics codes and with experimental data.« less

  6. Development of ORIGEN Libraries for Mixed Oxide (MOX) Fuel Assembly Designs

    SciTech Connect

    Mertyurek, Ugur; Gauld, Ian C.

    2015-12-24

    In this research, ORIGEN cross section libraries for reactor-grade mixed oxide (MOX) fuel assembly designs have been developed to provide fast and accurate depletion calculations to predict nuclide inventories, radiation sources and thermal decay heat information needed in safety evaluations and safeguards verification measurements of spent nuclear fuel. These ORIGEN libraries are generated using two-dimensional lattice physics assembly models that include enrichment zoning and cross section data based on ENDF/B-VII.0 evaluations. Using the SCALE depletion sequence, burnup-dependent cross sections are created for selected commercial reactor assembly designs and a representative range of reactor operating conditions, fuel enrichments, and fuel burnup. The burnup dependent cross sections are then interpolated to provide problem-dependent cross sections for ORIGEN, avoiding the need for time-consuming lattice physics calculations. The ORIGEN libraries for MOX assembly designs are validated against destructive radiochemical assay measurements of MOX fuel from the MALIBU international experimental program. This program included measurements of MOX fuel from a 15 × 15 pressurized water reactor assembly and a 9 × 9 boiling water reactor assembly. The ORIGEN MOX libraries are also compared against detailed assembly calculations from the Phase IV-B numerical MOX fuel burnup credit benchmark coordinated by the Nuclear Energy Agency within the Organization for Economic Cooperation and Development. Finally, the nuclide compositions calculated by ORIGEN using the MOX libraries are shown to be in good agreement with other physics codes and with experimental data.

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

    SciTech Connect

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

    1999-02-01

    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.

  8. Criticality experiments with mixed oxide fuel pin arrays in plutonium-uranium nitrate solution

    SciTech Connect

    Lloyd, R.C. ); Smolen, G.R. )

    1988-08-01

    A series of critical experiments was completed with mixed plutonium-uranium solutions having a Pu/(Pu + U) ratio of approximately 0.22 in a boiler tube-type lattice assembly. These experiments were conducted as part of the Criticality Data Development Program between the United States Department of Energy (USDOE) and the Power Reactor and Nuclear Fuel Development Corporation (PNC) of Japan. A complete description of the experiments and data are included in this report. The experiments were performed with an array of mixed oxide fuel pins in aqueous plutonium-uranium solutions. The fuel pins were contained in a boiler tube-type tank and arranged in a 1.4 cm square pitch array which resembled cylindrical geometry. One experiment was perfomed with the fuel pins removed from the vessel. The experiments were performed with a water reflector. The concentration of the solutions in the boiler tube-type tank was varied from 4 to 468 g (Pu + U)/liter. The ratio of plutonium to total heavy metal (plutonium plus uranium) was approximately 0.22 for all experiments.

  9. EBSD and TEM Characterization of High Burn-up Mixed Oxide Fuel

    SciTech Connect

    Teague, Melissa C.; Gorman, Brian P.; Miller, Brandon D.; King, Jeffrey

    2014-01-01

    Understanding and studying the irradiation behavior of high burn-up oxide fuel is critical to licensing of future fast breeder reactors. Advancements in experimental techniques and equipment are allowing for new insights into previously irradiated samples. In this work dual column focused ion beam (FIB)/scanning electron microscope (SEM) was utilized to prepared transmission electron microscope samples from mixed oxide fuel with a burn-up of 6.7% FIMA. Utilizing the FIB/SEM for preparation resulted in samples with a dose rate of <0.5 mRem/h compared to approximately 1.1 R/h for a traditionally prepared TEM sample. The TEM analysis showed that the sample taken from the cooler rim region of the fuel pellet had approximately 2.5x higher dislocation density than that of the sample taken from the mid-radius due to the lower irradiation temperature of the rim. The dual column FIB/SEM was additionally used to prepared and serially slice approximately 25 um cubes. High quality electron back scatter diffraction (EBSD) were collected from the face at each step, showing, for the first time, the ability to obtain EBSD data from high activity irradiated fuel.

  10. Oxidative potential of smoke from burning wood and mixed biomass fuels.

    PubMed

    Kurmi, O P; Dunster, C; Ayres, J G; Kelly, F J

    2013-10-01

    More than half the world's population still rely on burning biomass fuels to heat and light their homes and cook food. Household air pollution, a common component of which is inhalable particulate matter (PM), emitted from biomass burning is associated with increased vulnerability to respiratory infection and an enhanced risk of developing chronic obstructive pulmonary disease. In the light of an emerging hypothesis linking chronic PM exposure during childhood and increased vulnerability to respiratory diseases in adulthood, in a chain of events involving oxidative stress, reduced immunity and subsequent infection, the aim of this study was to characterise the oxidative potential (OP) of PM collected during the burning of wood and mixed biomass, whilst cooking food in the Kathmandu Valley, Nepal. Our assessments were based on the capacity of the particles to deplete the physiologically relevant antioxidants from a validated, synthetic respiratory tract lining fluid (RTLF). Incubation of mixed biomass and wood smoke particles suspensions with the synthetic RTLF for 4 h resulted in a mean loss of ascorbate of 64.76 ± 16.83% and 83.37 ± 14.12% at 50 μg/ml, respectively. Reduced glutathione was depleted by 49.29 ± 15.22% in mixed biomass and 65.33 ± 13.01% in wood smoke particles under the same conditions. Co-incubation with the transition metal chelator diethylenetriaminepentaacetate did not inhibit the rate of ascorbate oxidation, indicating a negligible contribution by redox-active metals in these samples. The capacity of biomass smoke particles to elicit oxidative stress certainly has the potential to contribute towards negative health impacts associated with traditional domestic fuels in the developing world. PMID:23926954

  11. Nitric Oxide PLIF Visualization of Simulated Fuel-Air Mixing in a Dual-Mode Scramjet

    NASA Technical Reports Server (NTRS)

    Cantu, Luca M. L.; Gallo, Emanuela C. A.; Cutler, Andrew D.; Bathel, Brett F.; Danehy, Paul M.; Rockwell, Robert D.; Goyne, Christopher P.; McDaniel, James C.

    2015-01-01

    Nitric oxide (NO) planar induced laser fluorescence (PLIF) measurements have been performed in a small scale scramjet combustor at the University of Virginia Aerospace Research Laboratory at nominal simulated Mach 5 flight. A mixture of NO and N2 was injected at the upstream end of the inlet isolator as a surrogate for ethylene fuel, and the mixing of this fuel simulant was studied with and without a shock train. The shock train was produced by an air throttle, which simulated the blockage effects of combustion downstream of the cavity flame holder. NO PLIF signal was imaged in a plane orthogonal to the freestream at the leading edge of the cavity. Instantaneous planar images were recorded and analyzed to identify the most uniform cases, which were achieved by varying the location of the fuel injection and shock train. This method was used to screen different possible fueling configurations to provide optimized test conditions for follow-on combustion measurements using ethylene fuel. A theoretical study of the selected NO rotational transitions was performed to obtain a LIF signal that is linear with NO mole fraction and approximately independent of pressure and temperature.

  12. Neutron Emission Characteristics of Two Mixed-Oxide Fuels: Simulations and Initial Experiments

    SciTech Connect

    D. L. Chichester; S. A. Pozzi; J. L. Dolan; M. Flaska; J. T. Johnson; E. H. Seabury; E. M. Gantz

    2009-07-01

    Simulations and experiments have been carried out to investigate the neutron emission characteristics of two mixed-oxide (MOX) fuels at Idaho National Laboratory (INL). These activities are part of a project studying advanced instrumentation techniques in support of the U.S. Department of Energy's Fuel Cycle Research and Development program and it's Materials Protection, Accounting, and Control for Transmutation (MPACT) campaign. This analysis used the MCNP-PoliMi Monte Carlo simulation tool to determine the relative strength and energy spectra of the different neutron source terms within these fuels, and then used this data to simulate the detection and measurement of these emissions using an array of liquid scintillator neutron spectrometers. These calculations accounted for neutrons generated from the spontaneous fission of the actinides in the MOX fuel as well as neutrons created via (alpha,n) reactions with oxygen in the MOX fuel. The analysis was carried out to allow for characterization of both neutron energy as well as neutron coincidences between multiple detectors. Coincidences between prompt gamma rays and neutrons were also analyzed. Experiments were performed at INL with the same materials used in the simulations to benchmark and begin validation tests of the simulations. Data was collected in these experiments using an array of four liquid scintillators and a high-speed waveform digitizer. Advanced digital pulse-shape discrimination algorithms were developed and used to collect this data. Results of the simulation and modeling studies are presented together with preliminary results from the experimental campaign.

  13. MCNP analysis of PNL split-table critical experiments containing mixed-oxide fuels

    SciTech Connect

    Abdurrahman, N.M.; Yavuz, M.; Radulescu, G.

    1997-12-01

    Pacific Northwest Laboratory (PNL) Split-Table Critical experiments containing mixed-oxide (MOX) fuels for various core configurations are studied using MCNP4A with the ENDF/B-VI continuous-energy library. These experiments were performed to provide necessary technical information and experimental criticality data that would serve as benchmark data in support of the liquid-metal fast breeder reactor program. Because of the current interest in the utilization of weapons-grade plutonium in the form of MOX fuel in light water reactors, such experimental data are extremely important for checking the performance of the modem computational tools. The {sup 239}Pu content in plutonium of the PNL MOX fuels is {approximately}91 wt%, which is very close to that of the weapons-grade {sup 239}Pu. The MOX fuels used in these critical experiments consist of 30.0, 14.62, and 7.89 wt% Pu and N{sub H}/(N{sub Pu} + Nu) moderation ratios (MRs) of 47.4, 30.6, and 51.8, respectively.

  14. Depletion analysis of mixed-oxide fuel pins in light water reactors and the Advanced Test Reactor

    SciTech Connect

    Chang, G.S.; Ryskamp, J.M.

    2000-03-01

    An experiment containing weapons-grade mixed-oxide (WG-MOX) fuel has been designed and is being irradiated in the Advanced Test Reactor (ATR) at the Idaho National Engineering and Environmental Laboratory (INEEL). The ability to accurately predict fuel pin performance is an essential requirement for the MOX fuel test assembly design. Detailed radial fission power and temperature profile effects and fission gas release in the fuel pin are a function of the fuel pin's temperature, fission power, and fission product ad actinide concentration profiles. In addition, the burnup-dependent profile analyses in irradiated fuel pins is important for fuel performance analysis to support the potential licensing of the MOX fuel made from WG-plutonium and depleted uranium for use in US reactors. The MCNP Coupling With ORIGEN2 burnup calculation code (MCWO) can analyze the detailed burnup profiles of WG-MOX and reactor-grade mixed-oxide (RG-MOX) fuel pins. The validated code MCWO can provide the best-estimate neutronic characteristics of fuel burnup performance analysis. Applying this capability with a new minicell method allows calculation of detailed nuclide concentration and power distributions within the MOX pins as a function of burnup. This methodology was applied to MOX fuel in a commercial pressurized water reactor and in an experiment currently being irradiated in the ATR. The prediction of nuclide concentration profiles and power distributions in irradiated MOX plus via this new methodology can provide insights into MOX fuel performance.

  15. Synthesis of alumina powder by the urea-glycine-nitrate combustion process: a mixed fuel approach to nanoscale metal oxides

    NASA Astrophysics Data System (ADS)

    Sharma, Amit; Rani, Amita; Singh, Ajay; Modi, O. P.; Gupta, Gaurav K.

    2014-03-01

    Main objective of present work is to study the efficiency of mixed fuel towards solution combustion synthesis of alumina powder, which otherwise prepared by single fuel and study of properties of final product with mixed fuel approach. Two different fuels, glycine and urea, along with aluminium nitrates have been used to prepare nanophase alumina powder. Different fuel to oxidizer ratios and different percentage combination of two fuels were used to prepare six samples. In all samples, nanoscale particle size obtained. Parameter which continuously changes the results of various characterisations is percentage combination of two fuels. In case where percentage of urea is higher than glycine reaction takes place with high exothermicity and hence crystallinity in product phase, whereas glycine promotes amorphous character. With mixed fuel approach, crystallinity can be enhanced easily, by calcinations of powder product at low temperature, because due to mixed urea and glycine, there is already some fraction of crystallinity observed. Overall mixed fuel approach has ability to produce nanophase alumina powder with wide range of particles size.

  16. Fuzzy Logic Based Controller for a Grid-Connected Solid Oxide Fuel Cell Power Plant.

    PubMed

    Chatterjee, Kalyan; Shankar, Ravi; Kumar, Amit

    2014-10-01

    This paper describes a mathematical model of a solid oxide fuel cell (SOFC) power plant integrated in a multimachine power system. The utilization factor of a fuel stack maintains steady state by tuning the fuel valve in the fuel processor at a rate proportional to a current drawn from the fuel stack. A suitable fuzzy logic control is used for the overall system, its objective being controlling the current drawn by the power conditioning unit and meet a desirable output power demand. The proposed control scheme is verified through computer simulations.

  17. Fuzzy Logic Based Controller for a Grid-Connected Solid Oxide Fuel Cell Power Plant.

    PubMed

    Chatterjee, Kalyan; Shankar, Ravi; Kumar, Amit

    2014-10-01

    This paper describes a mathematical model of a solid oxide fuel cell (SOFC) power plant integrated in a multimachine power system. The utilization factor of a fuel stack maintains steady state by tuning the fuel valve in the fuel processor at a rate proportional to a current drawn from the fuel stack. A suitable fuzzy logic control is used for the overall system, its objective being controlling the current drawn by the power conditioning unit and meet a desirable output power demand. The proposed control scheme is verified through computer simulations. PMID:25053926

  18. Americium and plutonium release behavior from irradiated mixed oxide fuel during heating

    NASA Astrophysics Data System (ADS)

    Sato, I.; Suto, M.; Miwa, S.; Hirosawa, T.; Koyama, S.

    2013-06-01

    The release behavior of Pu and Am was investigated under the reducing atmosphere expected in sodium cooled fast reactor severe accidents. Irradiated Pu and U mixed oxide fuels were heated at maximum temperatures of 2773 K and 3273 K. EPMA, γ-ray spectrometry and α-ray spectrometry for released and residual materials revealed that Pu and Am can be released more easily than U under the reducing atmosphere. The respective release rate coefficients for Pu and Am were obtained as 3.11 × 10-4 min-1 and 1.60 × 10-4 min-1 at 2773 K under the reducing atmosphere with oxygen partial pressure less than 0.02 Pa. Results of thermochemical calculations indicated that the main released chemical forms would likely be PuO for Pu and Am for Am under quite low oxygen partial pressure.

  19. 77 FR 70193 - Shaw Areva MOX Services (Mixed Oxide Fuel Fabrication Facility); Notice of Atomic Safety and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-23

    ... COMMISSION Shaw Areva MOX Services (Mixed Oxide Fuel Fabrication Facility); Notice of Atomic Safety and Licensing Board Reconstitution Pursuant to 10 CFR 2.313(c) and 2.321(b), the Atomic Safety and Licensing... Administrative Judge, Atomic Safety and Licensing Board Panel. BILLING CODE 7590-01-P...

  20. Improved mixed oxide fuel calculations with the evaluated nuclear data library JEFF-3.2

    DOE PAGES

    Noguere, G.; Bernard, D.; Blaise, P.; Bouland, O.; Leal, Luiz C.; Leconte, P.; Litaize, O.; Peneliau, Y.; Roque, B.; Santamarina, A.; et al

    2016-02-01

    In this study, an overestimation of the keff values for mixed oxide (MOX) fuels was identified with Monte Carlo (TRIPOLI-4) and deterministic (APOLLO2) calculations based on the Joint Evaluated Fission and Fusion (JEFF) evaluated nuclear data library. The overestimation becomes sizeable with Pit aging, reaching a reactivity change of Delta(p)similar or equal to+700 pcm for integral measurements carried out with MOX fuel containing a large amount of americium. This bias was observed for various critical configurations performed in the zero power reactor EOLE of the Commissariat a l'energie atomique et aux energies alternatives (CEA), Cadarache, France. The present work focusesmore » on the improvements achieved with the new 239PU and 241Am evaluated nuclear data files available in the latest version of the JEFF library (JEFF-3.2). The resolved resonance range of the plutonium evaluation was reevaluated at Oak Ridge National Laboratory (ORNL), Oak Ridge, Tennessee, with the Ski/NH code in collaboration with CEA Cadarache. The resonance parameters of the americium evaluation were obtained with the REFIT code in collaboration with the research institutes Institute for Reference Materials and Measurements aRmm, Geel, Belgium, and Institut de recherche sur les lois fondamentales de l'Univers ofio, Saclay, France.« less

  1. Analysis of optical density data generated from neutron radiographs of uranium-plutonium mixed oxide fuel pellets inside sealed nuclear fuel pins

    NASA Astrophysics Data System (ADS)

    Panakkal, J. P.; Ghosh, J. K.; Roy, P. R.

    1986-03-01

    A quantitative analysis of neutron radiographs of welded nuclear fuel pins containing uranium-plutonium mixed oxide fuel pellets has been carried out to obtain a simple model for the transmission of neutrons through fuel pins during neutron radiography. The optical density data obtained by detailed microdensitometer scanning across the image of pellets of varying plutonium enrichment has been correlated to the product of the macroscopic neutron cross section and the distance traversed by the neutrons. Based on the experimental data, a simple model which can be applied to fuel pins of different dimensions and plutonium enrichment has been derived.

  2. Performance of Thorium-Based Mixed Oxide Fuels for the Consumption of Plutonium in Current and Advanced Reactors

    SciTech Connect

    Weaver, Kevan Dean; Herring, James Stephen

    2003-07-01

    A renewed interest in thorium-based fuels has arisen lately based on the need for proliferation resistance, longer fuel cycles, higher burnup, and improved waste form characteristics. Recent studies have been directed toward homogeneously mixed, heterogeneously mixed, and seed-and-blanket thorium-uranium oxide fuel cycles that rely on "in situ" use of the bred-in 233U. However, due to the higher initial enrichment required to achieve acceptable burnups, these fuels are encountering economic constraints. Thorium can nevertheless play a large role in the nuclear fuel cycle, particularly in the reduction of plutonium inventories. While uranium-based mixed-oxide (MOX) fuel will decrease the amount of plutonium in discharged fuel, the reduction is limited due to the breeding of more plutonium (and higher actinides) from the 238U. Here, we present calculational results and a comparison of the potential burnup of a thorium-based and uranium-based mixed-oxide fuel in a light water reactor. Although the uranium-based fuels outperformed the thorium-based fuels in achievable burnup, a depletion comparison of the initially charged plutonium (both reactor and weapons grade) showed that the thorium-based fuels outperformed the uranium-based fuels by more that a factor of 2, where >70% of the total plutonium in the thorium-based fuel is consumed during the cycle. This is significant considering that the achievable burnups of the thorium-based fuels were 1.4 to 4.6 times less than the uranium-based fuels for similar plutonium enrichments. For equal specific burnups of ~60 MWd/kg (i.e., using variable plutonium weight percentages to give the desired burnup), the thorium-based fuels still outperform the uranium-based fuels by more than a factor of 2, where the total plutonium consumption in a three-batch, 18-month cycle was 60 to 70%. This is fairly significant considering that 10 to 15% (by weight) more plutonium is needed in the thorium-based fuels as compared to the uranium

  3. Solid oxide fuel cell power plant with an anode recycle loop turbocharger

    DOEpatents

    Saito, Kazuo; Skiba, Tommy; Patel, Kirtikumar H.

    2016-09-27

    An anode exhaust recycle turbocharger (100) has a turbocharger turbine (102) secured in fluid communication with a compressed oxidant stream within an oxidant inlet line (218) downstream from a compressed oxidant supply (104), and the anode exhaust recycle turbocharger (100) also includes a turbocharger compressor (106) mechanically linked to the turbocharger turbine (102) and secured in fluid communication with a flow of anode exhaust passing through an anode exhaust recycle loop (238) of the solid oxide fuel cell power plant (200). All or a portion of compressed oxidant within an oxidant inlet line (218) drives the turbocharger turbine (102) to thereby compress the anode exhaust stream in the recycle loop (238). A high-temperature, automotive-type turbocharger (100) replaces a recycle loop blower-compressor (52).

  4. Solid oxide fuel cell power plant with an anode recycle loop turbocharger

    SciTech Connect

    Saito, Kazuo; Skiba, Tommy; Patel, Kirtikumar H.

    2015-07-14

    An anode exhaust recycle turbocharger (100) has a turbocharger turbine (102) secured in fluid communication with a compressed oxidant stream within an oxidant inlet line (218) downstream from a compressed oxidant supply (104), and the anode exhaust recycle turbocharger (100) also includes a turbocharger compressor (106) mechanically linked to the turbocharger turbine (102) and secured in fluid communication with a flow of anode exhaust passing through an anode exhaust recycle loop (238) of the solid oxide fuel cell power plant (200). All or a portion of compressed oxidant within an oxidant inlet line (218) drives the turbocharger turbine (102) to thereby compress the anode exhaust stream in the recycle loop (238). A high-temperature, automotive-type turbocharger (100) replaces a recycle loop blower-compressor (52).

  5. Chemical thermodynamics of Cs and Te fission product interactions in irradiated LMFBR mixed-oxide fuel pins

    NASA Astrophysics Data System (ADS)

    Adamson, M. G.; Aitken, E. A.; Lindemer, T. B.

    1985-02-01

    A combination of fuel chemistry modelling and equilibrium thermodynamic calculations has been used to predict the atom ratios of Cs and Te fission products (Cs:Te) that find their way into the fuel-cladding interface region of irradiated stainless steel-clad mixed-oxide fast breeder reactor fuel pins. It has been concluded that the ratio of condensed, chemically-associated Cs and Te in the interface region,Čs:Te, which in turn determines the Te activity, is controlled by an equilibrium reaction between Cs 2Te and the oxide fuel, and that the value of Čs:Te is, depending on fuel 0:M, either equal to or slightly less than 2:1. Since Cs and Te fission products are both implicated as causative agents in FCCI (fission product-assisted inner surface attack of stainless steel cladding) and in FPLME (fission product-assisted liquid metal embrittlement of AISI-Type 316), the observed out-of-pile Cs:Te thresholds for FCCI (4˜:1) and FPLME (2˜:1) have been rationalized in terms of Cs:Te thermochemistry and phase equilibria. Also described in the paper is an updated chemical evolution model for reactive/volatile fission product behavior in irradiated oxide pins.

  6. Characterization and quantification of uncertainty in solid oxide fuel cell hybrid power plants

    NASA Astrophysics Data System (ADS)

    Subramanyan, Karthik; Diwekar, Urmila M.

    Distributed power generation is one of the most powerful applications of fuel cell technology. Several types of configurations have been hypothesized and tested for these kinds of applications at the conceptual level, but hybrid power plants are one of the most efficient. These are designs that combine the fuel cell cycle with other thermodynamic cycles to provide higher efficiency. The power plant in focus is the high pressure (HP)-low pressure (LP) solid oxide fuel cells (SOFC)/steam turbine (ST)/gas turbine (GT) configuration which is a part of the vision-21 program, which is a new approach, the U.S. Department of Energy's (DOE's) Office of Fossil Energy has begun, for developing 21st century energy plants that would have virtually no environmental impact. The overall goal is to effectively eliminate—at competitive costs—environmental concerns associated with the use of fossil fuels, for producing electricity and transportation fuels. In this design, coal is gasified in an entrained bed gasifier and the syn-gas produced is cleaned in a transport bed desulfurizer and passed over to cascaded SOFC modules (at two pressure levels). This module is integrated with a reheat GT cycle. The heat of the exhaust from the GT cycle is used to convert water to steam, which is eventually used in a steam bottoming cycle. Since this hybrid technology is new and futuristic, the system level models used for predicting the fuel cells' performance and for other modules like the desulfurizer have significant uncertainties in them. Also, the performance curves of the SOFC would differ depending on the materials used for the anode, cathode and electrolyte. The accurate characterization and quantification of these uncertainties is crucial for the validity of the model predictions and hence is the main focus of this paper. This work performs a two-level uncertainty analysis of the fuel cell module: uncertainty associated with (1) model and (2) material used for anode, cathode and

  7. Stabilizer for mixed fuels

    SciTech Connect

    Yamamura, M.; Igarashi, T.; Ukigai, T.

    1984-03-13

    A stabilizer for mixed fuels containing a reaction product obtained by reacting (1) a polyol having at least 3 hydroxyl groups in the molecule and a molecular weight of 400-10,000 with (2) an epihalohydrin, as the principal component.

  8. Mixed oxide solid solutions

    DOEpatents

    Magno, Scott; Wang, Ruiping; Derouane, Eric

    2003-01-01

    The present invention is a mixed oxide solid solution containing a tetravalent and a pentavalent cation that can be used as a support for a metal combustion catalyst. The invention is furthermore a combustion catalyst containing the mixed oxide solid solution and a method of making the mixed oxide solid solution. The tetravalent cation is zirconium(+4), hafnium(+4) or thorium(+4). In one embodiment, the pentavalent cation is tantalum(+5), niobium(+5) or bismuth(+5). Mixed oxide solid solutions of the present invention exhibit enhanced thermal stability, maintaining relatively high surface areas at high temperatures in the presence of water vapor.

  9. Zero Emission Power Plants Using Solid Oxide Fuel Cells and Oxygen Transport Membranes

    SciTech Connect

    Shockling, Larry A.; Huang, Keqin; Gilboy, Thomas E.; Christie, G. Maxwell; Raybold, Troy M.

    2001-11-06

    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

  10. Effect of the air-fuel mixing on the NOx yield in a low-emission gas-turbine plant combustor

    NASA Astrophysics Data System (ADS)

    Vasil'ev, V. D.; Bulysova, L. A.; Berne, A. L.

    2016-04-01

    The article deals with construction of a simplified model of inhibition of nitric oxides formed in the combustors of the gas-turbine plants (GTPs) operating on natural gas. A combustor in which premixed, lean air-fuel mixtures are burnt is studied theoretically and experimentally. The research was carried out using a full-scale combustor that had parameters characteristic of modern GTPs. The article presents the results computed by the FlowVision software and the results of the experiments carried out on the test bench of the All-Russia Thermal Engineering Institute. The calculations and the tests were conducted under the following conditions: a flow rate of approximately 4.6 kg/s, a pressure to 450 kPa, an air temperature at the combustor inlet of approximately 400°C, the outlet temperature t 3 ≤ 1200°C, and natural gas as the fuel. The comparison of the simulated parameters with the experimental results underlies the constructed correlation dependence of the experimental NO x emission on the calculated parameter of nonuniform fuel concentration at the premixing zone outlet. The postulate about a weak dependence of the emission of NO x formed upon combustion of a perfectly mixed air-fuel mixture—when the methane concentration in air is constant at any point of the air-fuel mixture, i.e., constant in the mixture bulk—on the pressure in the combustor has been experimentally proven. The correctness and the practicability of the stationary mathematical model of the mixing process used to assess the NO x emission by the calculated amount of the air-fuel mixture generated in the premixing zone has been validated. This eliminates some difficulties that arise in the course of calculation of combustion and formation of NO x .

  11. A novel approach for analyzing electrochemical properties of mixed conducting solid oxide fuel cell anode materials by impedance spectroscopy.

    PubMed

    Nenning, A; Opitz, A K; Huber, T M; Fleig, J

    2014-10-28

    For application of acceptor-doped mixed conducting oxides as solid oxide fuel cell (SOFC) anodes, high electrochemical surface activity as well as acceptable electronic and ionic conductivity are crucial. In a reducing atmosphere, particularly the electronic conductivity of acceptor-doped oxides can become rather low and the resulting complex interplay of electrochemical reactions and charge transport processes makes a mechanistic interpretation of impedance measurements very complicated. In order to determine all relevant resistive and capacitive contributions of mixed conducting electrodes in a reducing atmosphere, a novel electrode design and impedance-based analysis technique is therefore introduced. Two interdigitating metallic current collectors are placed in a microelectrode, which allows in-plane measurements within the electrode as well as electrochemical measurements versus a counter electrode. Equivalent circuit models for quantifying the spectra of both measurement modes are developed and applied to simultaneously fit both spectra, using the same parameter set. In this manner, the electronic and ionic conductivity of the material as well as the area-specific resistance of the surface reaction and the chemical capacitance can be determined on a single microelectrode in a H2-H2O atmosphere. The applicability of this new tool was demonstrated in SrTi0.7Fe0.3O(3-δ) (STFO) thin film microelectrodes, deposited on single-crystalline yttria-stabilized zirconia (YSZ) substrates. All materials parameters that contribute to the polarization resistance of STFO electrodes in a reducing atmosphere could thus be quantified.

  12. HETEROGENEOUS REBURNING BY MIXED FUELS

    SciTech Connect

    Wei-Yin Chen; Benson B. Gathitu

    2005-01-14

    Recent studies of heterogeneous reburning, i.e., reburning involving a coal-derived char, have elucidated its variables, kinetics and mechanisms that are valuable to the development of a highly efficient reburning process. Young lignite chars contain catalysts that not only reduce NO, but they also reduce HCN that is an important intermediate that recycles to NO in the burnout zone. Gaseous CO scavenges the surface oxides that are formed during NO reduction, regenerating the active sites on the char surface. Based on this mechanistic information, cost-effective mixed fuels containing these multiple features has been designed and tested in a simulated reburning apparatus. Remarkably high reduction of NO and HCN has been observed and it is anticipated that mixed fuel will remove 85% of NO in a three-stage reburning process.

  13. Heterogeneous Reburning By Mixed Fuels

    SciTech Connect

    Anderson Hall

    2009-03-31

    Recent studies of heterogeneous reburning, i.e., reburning involving a coal-derived char, have elucidated its variables, kinetics and mechanisms that are valuable to the development of a highly efficient reburning process. Young lignite chars contain catalysts that not only reduce NO, but they also reduce HCN that is an important intermediate that recycles to NO in the burnout zone. Gaseous CO scavenges the surface oxides that are formed during NO reduction, regenerating the active sites on the char surface. Based on this mechanistic information, cost-effective mixed fuels containing these multiple features has been designed and tested in a simulated reburning apparatus. Remarkably high reduction of NO and HCN has been observed and it is anticipated that mixed fuel will remove 85% of NO in a three-stage reburning process.

  14. Solid oxide fuel cell power plant having a bootstrap start-up system

    DOEpatents

    Lines, Michael T

    2016-10-04

    The bootstrap start-up system (42) achieves an efficient start-up of the power plant (10) that minimizes formation of soot within a reformed hydrogen rich fuel. A burner (48) receives un-reformed fuel directly from the fuel supply (30) and combusts the fuel to heat cathode air which then heats an electrolyte (24) within the fuel cell (12). A dilute hydrogen forming gas (68) cycles through a sealed heat-cycling loop (66) to transfer heat and generated steam from an anode side (32) of the electrolyte (24) through fuel processing system (36) components (38, 40) and back to an anode flow field (26) until fuel processing system components (38, 40) achieve predetermined optimal temperatures and steam content. Then, the heat-cycling loop (66) is unsealed and the un-reformed fuel is admitted into the fuel processing system (36) and anode flow (26) field to commence ordinary operation of the power plant (10).

  15. OXIDATION OF MERCURY ACROSS SCR CATALYSTS IN COAL-FIRED POWER PLANTS BURNING LOW RANK FUELS

    SciTech Connect

    Constance Senior

    2004-12-31

    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.

  16. MCNP-to-TORT radiation transport calculations in support of mixed oxide fuels testing for the Fissile Materials Disposition Program

    SciTech Connect

    Pace, J.V. III

    1998-04-01

    The US (US) Department of Energy Fissile Materials Disposition Program has begun studies for disposal of surplus weapons-grade plutonium (WG-Pu) as mixed uranium plutonium oxide (MOX) fuel for commercial light water reactors (LWRs). Currently MOX fuel is used commercially in a number of foreign countries, but is not in the US. Most of the experience is with reactor grade plutonium (RG-Pu) in MOX fuel. Therefore, to use WG-Pu in MOX fuel, one must demonstrate that the experience with RG-Pu is relevant. As a first step in this program, the utilization of WG-Pu in a LWR environment must be demonstrated. To accomplish this, a test is to be conducted to investigate some of the unresolved issues. The initial tests will be made in an I-hole of the Advanced Test Reactor (ATR) at the Idaho National Engineering and Environmental Laboratory (INEEL). Initial radiation transport calculations of the test specimens were made at INEEL using the MCNP Monte Carlo radiation transport code. These calculations were made to determine the linear heating rates in the fuel specimens. Unfortunately, the results of the calculations could not show the detailed high and low power density spots in the specimens. However, a discrete ordinates radiation transport code could pinpoint these spatial details. Therefore, INEEL was tasked with producing a MCNP source at the boundary of a rectangular parallelepiped enclosing the ATR I-hole, and Oak Ridge National Laboratory was tasked with transforming this boundary source into a discrete ordinates boundary source for the Three-dimensional Oak Ridge radiation Transport (TORT) code. Thus, the TORT results not only complemented, but also were in agreement with the MCNP results.

  17. Enhancement of electricity production by graphene oxide in soil microbial fuel cells and plant microbial fuel cells.

    PubMed

    Goto, Yuko; Yoshida, Naoko; Umeyama, Yuto; Yamada, Takeshi; Tero, Ryugo; Hiraishi, Akira

    2015-01-01

    The effects of graphene oxide (GO) on electricity generation in soil microbial fuel cells (SMFCs) and plant microbial fuel cell (PMFCs) were investigated. GO at concentrations ranging from 0 to 1.9 g⋅kg(-1) was added to soil and reduced for 10 days under anaerobic incubation. All SMFCs (GO-SMFCs) utilizing the soils incubated with GO produced electricity at a greater rate and in higher quantities than the SMFCs which did not contain GO. In fed-batch operations, the overall average electricity generation in GO-SMFCs containing 1.0 g⋅kg(-1) of GO was 40 ± 19 mW⋅m(-2), which was significantly higher than the value of 6.6 ± 8.9 mW⋅m(-2) generated from GO-free SMFCs (p < 0.05). The increase in catalytic current at the oxidative potential was observed by cyclic voltammetry (CV) for GO-SMFC, with the CV curve suggesting the enhancement of electron transfer from oxidation of organic substances in the soil by the reduced form of GO. The GO-containing PMFC also displayed a greater generation of electricity compared to the PMFC with no added GO, with GO-PMFC producing 49 mW⋅m(-2) of electricity after 27 days of operation. Collectively, this study demonstrates that GO added to soil can be microbially reduced in soil, and facilitates electron transfer to the anode in both SMFCs and PMFCs.

  18. Enhancement of Electricity Production by Graphene Oxide in Soil Microbial Fuel Cells and Plant Microbial Fuel Cells

    PubMed Central

    Goto, Yuko; Yoshida, Naoko; Umeyama, Yuto; Yamada, Takeshi; Tero, Ryugo; Hiraishi, Akira

    2015-01-01

    The effects of graphene oxide (GO) on electricity generation in soil microbial fuel cells (SMFCs) and plant microbial fuel cell (PMFCs) were investigated. GO at concentrations ranging from 0 to 1.9 g⋅kg−1 was added to soil and reduced for 10 days under anaerobic incubation. All SMFCs (GO-SMFCs) utilizing the soils incubated with GO produced electricity at a greater rate and in higher quantities than the SMFCs which did not contain GO. In fed-batch operations, the overall average electricity generation in GO-SMFCs containing 1.0 g⋅kg−1 of GO was 40 ± 19 mW⋅m−2, which was significantly higher than the value of 6.6 ± 8.9 mW⋅m−2 generated from GO-free SMFCs (p < 0.05). The increase in catalytic current at the oxidative potential was observed by cyclic voltammetry (CV) for GO-SMFC, with the CV curve suggesting the enhancement of electron transfer from oxidation of organic substances in the soil by the reduced form of GO. The GO-containing PMFC also displayed a greater generation of electricity compared to the PMFC with no added GO, with GO-PMFC producing 49 mW⋅m−2 of electricity after 27 days of operation. Collectively, this study demonstrates that GO added to soil can be microbially reduced in soil, and facilitates electron transfer to the anode in both SMFCs and PMFCs. PMID:25883931

  19. Opportunities for mixed oxide fuel testing in the advanced test reactor to support plutonium disposition

    SciTech Connect

    Terry, W.K.; Ryskamp, J.M.; Sterbentz, J.W.

    1995-08-01

    Numerous technical issues must be resolved before LWR operating licenses can be amended to allow the use of MOX fuel. These issues include the following: (1) MOX fuel fabrication process verification; (2) Whether and how to use burnable poisons to depress MOX fuel initial reactivity, which is higher than that of urania; (3) The effects of WGPu isotopic composition; (4) The feasibility of loading MOX fuel with plutonia content up to 7% by weight; (5) The effects of americium and gallium in WGPu; (6) Fission gas release from MOX fuel pellets made from WGPu; (7) Fuel/cladding gap closure; (8) The effects of power cycling and off-normal events on fuel integrity; (9) Development of radial distributions of burnup and fission products; (10) Power spiking near the interfaces of MOX and urania fuel assemblies; and (11) Fuel performance code validation. The Advanced Test Reactor (ATR) at the Idaho National Engineering Laboratory possesses many advantages for performing tests to resolve most of the issues identified above. We have performed calculations to show that the use of hafnium shrouds can produce spectrum adjustments that will bring the flux spectrum in ATR test loops into a good approximation to the spectrum anticipated in a commercial LWR containing MOX fuel while allowing operation of the test fuel assemblies near their optimum values of linear heat generation rate. The ATR would be a nearly ideal test bed for developing data needed to support applications to license LWRs for operation with MOX fuel made from weapons-grade plutonium. The requirements for planning and implementing a test program in the ATR have been identified. The facilities at Argonne National Laboratory-West can meet all potential needs for pre- and post-irradiation examination that might arise in a MOX fuel qualification program.

  20. Mixed Acid Oxidation

    SciTech Connect

    Pierce, R.A.

    1999-10-26

    Several non-thermal processes have been developed to destroy organic waste compounds using chemicals with high oxidation potentials. These efforts have focused on developing technologies that work at low temperatures, relative to incineration, to overcome many of the regulatory issues associated with obtaining permits for waste incinerators. One such technique with great flexibility is mixed acid oxidation. Mixed acid oxidation, developed at the Savannah River Site, uses a mixture of an oxidant (nitric acid) and a carrier acid (phosphoric acid). The carrier acid acts as a non-volatile holding medium for the somewhat volatile oxidant. The combination of acids allows appreciable amounts of the concentrated oxidant to remain in the carrier acid well above the oxidant''s normal boiling point.

  1. Research and development of americium-containing mixed oxide fuel for fast reactors

    SciTech Connect

    Tanaka, Kosuke; Osaka, Masahiko; Sato, Isamu; Miwa, Shuhei; Koyama, Shin-ichi; Ishi, Yohei; Hirosawa, Takashi; Obayashi, Hiroshi; Yoshimochi, Hiroshi; Tanaka, Kenya

    2007-07-01

    The present status of the R and D program for americium-containing MOX fuel is reported. Successful achievements for development of fabrication technology with remote handling and evaluation of irradiation behavior together with evaluation of thermo-chemical properties based on the out-of-pile experiments are mentioned with emphasis on effects of Am addition on the MOX fuel properties. (authors)

  2. MCNP-to-TORT Radiation Transport Calculations in Support of Mixed Oxide Fuels Testing for the Fissile Materials Disposition Program

    SciTech Connect

    Pace, J.V.

    1999-11-01

    The United States (US) Department of Energy Fissile Materials Disposition Program (FMDP) began studies for disposal of surplus weapons-grade plutonium (WG-Pu) as mixed uranium-plutonium oxide (@40X) fuel for commercial light-water reactors(LWRS). As a first step in this program, a test of the utilization of WG-Pu in a LWR environment is being conducted in an I-hole of the Advanced Test Reactor (ATR) at the Idaho National Engineering and Environmental Laboratory (INEEL). Initial radiation transport calculations of the test specimens were made at INEEL using the MCNP Monte Carlo radiation transport code to determine the linear heating rates in the fuel specimens. Unfortunately, the results of the calculations could not show the detailed high and low power-density spots in the specimens. Therefore, INEEL produced an MCNP source at the boundary of a rectangular parallelepiped enclosing the ATR I-hole, and Oak Ridge National Laboratory (ORNL) transformed this boundary source into a discrete -ordinates boundary source for the Three-dimensional Oak Ridge radiation Transport (TORT) code to pinpoint spatial detail. Agreement with average MCNP results were within 5%.

  3. OXIDATION OF MERCURY ACROSS SCR CATALYSTS IN COAL-FIRED POWER PLANTS BURNING LOW RANK FUELS

    SciTech Connect

    Constance Senior; Temi Linjewile

    2003-07-25

    This is the first 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 Ceramics 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, analysis of the coal, ash and mercury speciation data from the first test series was completed. Good agreement was shown between different methods of measuring mercury in the flue gas: Ontario Hydro, semi-continuous emission monitor (SCEM) and coal composition. There was a loss of total mercury across the commercial catalysts, but not across the blank monolith. The blank monolith showed no oxidation. The data from the first test series show the same trend in mercury oxidation as a function of space velocity that has been seen elsewhere. At space velocities in the range of 6,000-7,000 hr{sup -1} the blank monolith did not show any mercury oxidation, with or without ammonia present. Two of the commercial catalysts clearly showed an effect of ammonia. Two other commercial catalysts showed an effect of ammonia, although the error bars for the no-ammonia case are large. A test plan was written for the second test series and is being reviewed.

  4. Fully Coupled Modeling of Burnup-Dependent (U1- y , Pu y )O2- x Mixed Oxide Fast Reactor Fuel Performance

    NASA Astrophysics Data System (ADS)

    Liu, Rong; Zhou, Wenzhong; Zhou, Wei

    2016-03-01

    During the fast reactor nuclear fuel fission reaction, fission gases accumulate and form pores with the increase of fuel burnup, which decreases the fuel thermal conductivity, leading to overheating of the fuel element. The diffusion of plutonium and oxygen with high temperature gradient is also one of the important fuel performance concerns as it will affect the fuel material properties, power distribution, and overall performance of the fuel pin. In order to investigate these important issues, the (U1- y Pu y )O2- x fuel pellet is studied by fully coupling thermal transport, deformation, oxygen diffusion, fission gas release and swelling, and plutonium redistribution to evaluate the effects on each other with burnup-dependent models, accounting for the evolution of fuel porosity. The approach was developed using self-defined multiphysics models based on the framework of COMSOL Multiphysics to manage the nonlinearities associated with fast reactor mixed oxide fuel performance analysis. The modeling results showed a consistent fuel performance comparable with the previous results. Burnup degrades the fuel thermal conductivity, resulting in a significant fuel temperature increase. The fission gas release increased rapidly first and then steadily with the burnup increase. The fuel porosity increased dramatically at the beginning of the burnup and then kept constant as the fission gas released to the fuel free volume, causing the fuel temperature to increase. Another important finding is that the deviation from stoichiometry of oxygen affects greatly not only the fuel properties, for example, thermal conductivity, but also the fuel performance, for example, temperature distribution, porosity evolution, grain size growth, fission gas release, deformation, and plutonium redistribution. Special attention needs to be paid to the deviation from stoichiometry of oxygen in fuel fabrication. Plutonium content will also affect the fuel material properties and performance

  5. Manganese-Cobalt Mixed Spinel Oxides as Surface Modifiers for Stainless Steel Interconnects of Solid Oxide Fuel Cells

    SciTech Connect

    Xia, Gordon; Yang, Z Gary; Stevenson, Jeffry W.

    2006-11-06

    Ferritic stainless steels are promising candidates for interconnect applications in low- and mid-temperature solid oxide fuel cells (SOFCs). A couple of issues however remain for the particular application, including the chromium poisoning due to chromia evaporation, and long-term surface and electrical stability of the scale grown on these steels. Application of a manganese colbaltite spinel protection layer on the steels appears to be an effective approach to solve the issues. For an optimized performance, Mn{sub 1+x}Co{sub 2-x}O{sub 4} (-1 {le} x {le} 2) spinels were investigated against properties relative for protection coating applications on ferritic SOFC interconnects. Overall it appears that the spinels with x around 0.5 demonstrate a good CTE match to ceramic cell components, a relative high electrical conductivity, and a good thermal stability up to 1,250 C. This was confirmed by a long-term test on the Mn{sub 1.5}Co{sub 1.5}O{sub 4} protection layer that was thermally grown on Crofer22 APU, indicating the spinel protection layer not only significantly decreased the contact resistance between a LSF cathode and the stainless steel interconnects, but also inhibited the sub-scale growth on the stainless steels.

  6. Fuel cell system modeling for solid oxide fuel cell/gas turbine hybrid power plants, Part I: Modeling and simulation framework

    NASA Astrophysics Data System (ADS)

    Leucht, Florian; Bessler, Wolfgang G.; Kallo, Josef; Friedrich, K. Andreas; Müller-Steinhagen, H.

    A sustainable future power supply requires high fuel-to-electricity conversion efficiencies even in small-scale power plants. A promising technology to reach this goal is a hybrid power plant in which a gas turbine (GT) is coupled with a solid oxide fuel cell (SOFC). This paper presents a dynamic model of a pressurized SOFC system consisting of the fuel cell stack with combustion zone and balance-of-plant components such as desulphurization, humidification, reformer, ejector and heat exchangers. The model includes thermal coupling between the different components. A number of control loops for fuel and air flows as well as power management are integrated in order to keep the system within the desired operation window. Models and controls are implemented in a MATLAB/SIMULINK environment. Different hybrid cycles proposed earlier are discussed and a preferred cycle is developed. Simulation results show the prospects of the developed modeling and control system.

  7. Study on Equilibrium Characteristics of Thorium-Plutonium-Minor Actinides Mixed Oxides Fuel in PWR

    SciTech Connect

    Waris, A.; Permana, S.; Kurniadi, R.; Su'ud, Z.; Sekimoto, H.

    2010-06-22

    A study on characteristics of thorium-plutonium-minor actinides utilization in the pressurized water reactor (PWR) with the equilibrium burnup model has been conducted. For a comprehensive evaluation, several fuel cycles scenario have been included in the present study with the variation of moderator-to-fuel volume ratio (MFR) of PWR core design. The results obviously exhibit that the neutron spectra grow to be harder with decreasing of the MFR. Moreover, the neutron spectra also turn into harder with the rising number of confined heavy nuclides. The required {sup 233}U concentration for criticality of reactor augments with the increasing of MFR for all heavy nuclides confinement and thorium and uranium confinement in PWR.

  8. Generator module architecture for a large solid oxide fuel cell power plant

    SciTech Connect

    Gillett, James E.; Zafred, Paolo R.; Riggle, Matthew W.; Litzinger, Kevin P.

    2013-06-11

    A solid oxide fuel cell module contains a plurality of integral bundle assemblies, the module containing a top portion with an inlet fuel plenum and a bottom portion receiving air inlet feed and containing a base support, the base supports dense, ceramic exhaust manifolds which are below and connect to air feed tubes located in a recuperator zone, the air feed tubes passing into the center of inverted, tubular, elongated, hollow electrically connected solid oxide fuel cells having an open end above a combustion zone into which the air feed tubes pass and a closed end near the inlet fuel plenum, where the fuel cells comprise a fuel cell stack bundle all surrounded within an outer module enclosure having top power leads to provide electrical output from the stack bundle, where the fuel cells operate in the fuel cell mode and where the base support and bottom ceramic air exhaust manifolds carry from 85% to all 100% of the weight of the stack, and each bundle assembly has its own control for vertical and horizontal thermal expansion control.

  9. Performance of Thorium-Based Mixed Oxide Fuels for the Consumption of Plutonium and Minor Actinides in Current and Advanced Reactors

    SciTech Connect

    Weaver, Kevan Dean; Herring, James Stephen

    2002-06-01

    A renewed interest in thorium-based fuels has arisen lately based on the need for proliferation resistance, longer fuel cycles, higher burnup and improved wasteform characteristics. Recent studies have been directed toward homogeneously mixed, heterogeneously mixed, and seed-and-blanket thorium-uranium fuel cycles that rely on "in situ" use of the bred-in U-233. However, due to the higher initial enrichment required to achieve acceptable burnups, these fuels are encountering economic constraints. Thorium can nevertheless play a large role in the nuclear fuel cycle; particularly in the reduction of plutonium. While uranium-based mixedoxide (MOX) fuel will decrease the amount of plutonium, the reduction is limited due to the breeding of more plutonium (and higher actinides) from the U-238. Here we present calculational results and a comparison of the potential burnup of a thorium-based and uranium-based mixed oxide fuel in a light water reactor (LWR). Although the uranium-based fuels outperformed the thorium-based fuels in achievable burnup, a depletion comparison of the initially charged plutonium (both reactor and weapons grade) showed that the thorium-based fuels outperformed the uranium-based fuels by more that a factor of 2; where more than 70% of the total plutonium in the thorium-based fuel is consumed during the cycle. This is significant considering that the achievable burnup of the thorium-based fuels were 1.4 to 4.6 times less than the uranium-based fuels. Furthermore, use of a thorium-based fuel could also be used as a strategy for reducing the amount of long-lived nuclides (including the minor actinides), and thus the radiotoxicity in spent nuclear fuel. Although the breeding of U-233 is a concern, the presence of U-232 and its daughter products can aid in making this fuel self-protecting, and/or enough U-238 can be added to denature the fissile uranium. From these calculations, it appears that thorium-based fuel for plutonium incineration is superior as

  10. Multivariable Robust Control of a Simulated Hybrid Solid Oxide Fuel Cell Gas Turbine Plant

    SciTech Connect

    Tsai, Alex; Banta, Larry; Tucker, David; Gemmen, Randall

    2010-08-01

    This work presents a systematic approach to the multivariable robust control of a hybrid fuel cell gas turbine plant. The hybrid configuration under investigation built by the National Energy Technology Laboratory comprises a physical simulation of a 300kW fuel cell coupled to a 120kW auxiliary power unit single spool gas turbine. The public facility provides for the testing and simulation of different fuel cell models that in turn help identify the key difficulties encountered in the transient operation of such systems. An empirical model of the built facility comprising a simulated fuel cell cathode volume and balance of plant components is derived via frequency response data. Through the modulation of various airflow bypass valves within the hybrid configuration, Bode plots are used to derive key input/output interactions in transfer function format. A multivariate system is then built from individual transfer functions, creating a matrix that serves as the nominal plant in an H{sub {infinity}} robust control algorithm. The controller’s main objective is to track and maintain hybrid operational constraints in the fuel cell’s cathode airflow, and the turbo machinery states of temperature and speed, under transient disturbances. This algorithm is then tested on a Simulink/MatLab platform for various perturbations of load and fuel cell heat effluence. As a complementary tool to the aforementioned empirical plant, a nonlinear analytical model faithful to the existing process and instrumentation arrangement is evaluated and designed in the Simulink environment. This parallel task intends to serve as a building block to scalable hybrid configurations that might require a more detailed nonlinear representation for a wide variety of controller schemes and hardware implementations.

  11. Project proposals on the creation of Russian-American joint enterprise for investigation, development and manufacture of power plants on the basis of solid oxide fuel cells

    SciTech Connect

    Smotrov, N.V.; Kleschev, Yu.N.

    1996-04-01

    This paper describes a proposal for a joint Russian-American enterprise for performing scientific investigations, development, and manufacture of fuel cell power plants on the basis of the solid oxide fuel cell. RASOFCo. Russian-American Solid Oxide Fuel Cells Company. RASOFCo will provide the series output of the electrochemical generator (ECG) of 1kW power, then of 5kW and 10kW as well as the development and the output of 10kW power plant with the subsequent output of a power plant of greater power. An ECG based on solid oxide fuel cells uses methane as a fuel. Predicted technical characteristics, market analysis, assessment of potential demands for power plants of low power for Tyumentransgas, participants of the joint enterprise and their founding contributions, strategy for manufacture and financing, and management of RASOFCo are discussed.

  12. Angular-resolution and material-characterization measurements for a dual-particle imaging system with mixed-oxide fuel

    NASA Astrophysics Data System (ADS)

    Poitrasson-Rivière, Alexis; Polack, J. Kyle; Hamel, Michael C.; Klemm, Dietrich D.; Ito, Kai; McSpaden, Alexander T.; Flaska, Marek; Clarke, Shaun D.; Pozzi, Sara A.; Tomanin, Alice; Peerani, Paolo

    2015-10-01

    A dual-particle imaging (DPI) system, capable of simultaneously imaging fast neutrons and gamma rays, has been operated in the presence of mixed-oxide (MOX) fuel to assess the system's angular resolution and material-characterization capabilities. The detection principle is based on the scattering physics of neutrons (elastic scattering) and gamma rays (Compton scattering) in organic and inorganic scintillators. The detection system is designed as a combination of a two-plane Compton camera and a neutron-scatter camera. The front plane consists of EJ-309 liquid scintillators and the back plane consists of interleaved EJ-309 and NaI(Tl) scintillators. MCNPX-PoliMi was used to optimize the geometry of the system and the resulting prototype was built and tested using a Cf-252 source as an SNM surrogate. A software package was developed to acquire and process data in real time. The software was used for a measurement campaign to assess the angular resolution of the imaging system with MOX samples. Measurements of two MOX canisters of similar isotopics and intensity were performed for 6 different canister separations (from 5° to 30°, corresponding to distances of 21 cm and 131 cm, respectively). The measurements yielded a minimum separation of 20° at 2.5 m (86-cm separation) required to see 2 separate hot spots. Additionally, the results displayed good agreement with MCNPX-PoliMi simulations. These results indicate an angular resolution between 15° and 20°, given the 5° step. Coupled with its large field of view, and its capability to differentiate between spontaneous fission and (α,n) sources, the DPI system shows its potential for nuclear-nonproliferation applications.

  13. Rational design of mixed ionic and electronic conducting perovskite oxides for solid oxide fuel cell anode materials: A case study for doped SrTiO3

    SciTech Connect

    Suthirakun, Suwit; Xiao, Guoliang; Ammal, Salai Cheettu; Chen, Fanglin; zur Loye, Hans-Conrad; Heyden, Andreas

    2014-01-01

    The effect of p- and n-type dopants on ionic and electronic conductivity of SrTiO3 based perovskites were investigated both computationally and experimentally. Specifically, we performed density functional theory (DFT) calculations of Na- and La-doped SrTiO3 and Na- and Nb-doped SrTiO3 systems. Constrained ab initio thermodynamic calculations were used to evaluate the phase stability and reducibility of doped SrTiO3 under both oxidizing and reducing synthesis conditions, as well as under anodic solid oxide fuel cell (SOFC) conditions. The density of states (DOS) of these materials was analyzed to study the effects of p- and n-doping on the electronic conductivity. Furthermore, Na- and La-doped SrTiO3 and Na- and Nb-doped SrTiO3 samples were experimentally prepared and the conductivity was measured to confirm our computational predictions. The experimental observations are in very good agreement with the theoretical predictions that doping n-doped SrTiO3 with small amounts of p-type dopants promotes both the ionic and electronic conductivity of the material. This doping strategy is valid independent of p- and n-doping site and permits the synthesis of perovskite based mixed ionic/electronic conductors.

  14. Criticality Safety Scoping Study for the Transport of Weapons-Grade Mixed-Oxide Fuel Using the MO-1 Shipping Package

    SciTech Connect

    Dunn, M.E.; Fox, P.B.

    1999-05-01

    This report provides the criticality safety information needed for obtaining certification of the shipment of mixed-oxide (MOX) fuel using the MO-1 [USA/9069/B()F] shipping package. Specifically, this report addresses the shipment of non-weapons-grade MOX fuel as certified under Certificate of Compliance 9069, Revision 10. The report further addresses the shipment of weapons-grade MOX fuel using a possible Westinghouse fuel design. Criticality safety analysis information is provided to demonstrate that the requirements of 10 CFR S 71.55 and 71.59 are satisfied for the MO-1 package. Using NUREG/CR-5661 as a guide, a transport index (TI) for criticality control is determined for the shipment of non-weapons-grade MOX fuel as specified in Certificate of Compliance 9069, Revision 10. A TI for criticality control is also determined for the shipment of weapons-grade MOX fuel. Since the possible weapons-grade fuel design is preliminary in nature, this report is considered to be a scoping evaluation and is not intended as a substitute for the final criticality safety analysis of the MO-1 shipping package. However, the criticality safety evaluation information that is presented in this report does demonstrate the feasibility of obtaining certification for the transport of weapons-grade MOX lead test fuel using the MO-1 shipping package.

  15. Energy analysis of a combined solid oxide fuel cell with a steam turbine power plant for marine applications

    NASA Astrophysics Data System (ADS)

    Welaya, Yousri M. A.; Mosleh, M.; Ammar, Nader R.

    2013-12-01

    Strong restrictions on emissions from marine power plants (particularly SO x , NO x ) will probably be adopted in the near future. In this paper, a combined solid oxide fuel cell (SOFC) and steam turbine fuelled by natural gas is proposed as an attractive option to limit the environmental impact of the marine sector. The analyzed variant of the combined cycle includes a SOFC operated with natural gas fuel and a steam turbine with a single-pressure waste heat boiler. The calculations were performed for two types of tubular and planar SOFCs, each with an output power of 18 MW. This paper includes a detailed energy analysis of the combined system. Mass and energy balances are performed not only for the whole plant but also for each component in order to evaluate the thermal efficiency of the combined cycle. In addition, the effects of using natural gas as a fuel on the fuel cell voltage and performance are investigated. It has been found that a high overall efficiency approaching 60% may be achieved with an optimum configuration using the SOFC system. The hybrid system would also reduce emissions, fuel consumption, and improve the total system efficiency.

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

    NASA Technical Reports Server (NTRS)

    Veyo, S.E.

    1997-01-01

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

  17. Experiment Safety Assurance Package for Mixed Oxide Fuel Irradiation in an Average Power Position (I-24) in the Advanced Test Reactor

    SciTech Connect

    J. M . Ryskamp; R. C. Howard; R. C. Pedersen; S. T. Khericha

    1998-10-01

    The Fissile Material Disposition Program Light Water Reactor Mixed Oxide Fuel Irradiation Test Project Plan details a series of test irradiations designed to investigate the use of weapons-grade plutonium in MOX fuel for light water reactors (LWR) (Cowell 1996a, Cowell 1997a, Thoms 1997a). Commercial MOX fuel has been successfully used in overseas reactors for many years; however, weapons-derived test fuel contains small amounts of gallium (about 2 parts per million). A concern exists that the gallium may migrate out of the fuel and into the clad, inducing embrittlement. For preliminary out-of-pile experiments, Wilson (1997) states that intermetallic compound formation is the principal interaction mechanism between zircaloy cladding and gallium. This interaction is very limited by the low mass of gallium, so problems are not expected with the zircaloy cladding, but an in-pile experiment is needed to confirm the out-of-pile experiments. Ryskamp (1998) provides an overview of this experiment and its documentation. The purpose of this Experiment Safety Assurance Package (ESAP) is to demonstrate the safe irradiation and handling of the mixed uranium and plutonium oxide (MOX) Fuel Average Power Test (APT) experiment as required by Advanced Test Reactor (ATR) Technical Safety Requirement (TSR) 3.9.1 (LMITCO 1998). This ESAP addresses the specific operation of the MOX Fuel APT experiment with respect to the operating envelope for irradiation established by the Upgraded Final Safety Analysis Report (UFSAR) Lockheed Martin Idaho Technologies Company (LMITCO 1997a). Experiment handling activities are discussed herein.

  18. Solid oxide fuel cell/gas turbine power plant cycles and performance estimates

    SciTech Connect

    Lundberg, W.L.

    1996-12-31

    SOFC pressurization enhances SOFC efficiency and power performance. It enables the direct integration of the SOFC and gas turbine technologies which can form the basis for very efficient combined- cycle power plants. PSOFC/GT cogeneration systems, producing steam and/or hot water in addition to electric power, can be designed to achieve high fuel effectiveness values. A wide range of steam pressures and temperatures are possible owing to system component arrangement flexibility. It is anticipated that Westinghouse will offer small PSOFC/GT power plants for sale early in the next decade. These plants will have capacities less than 10 MW net ac, and they will operate with efficiencies in the 60-65% (net ac/LHV) range.

  19. Large size biogas-fed Solid Oxide Fuel Cell power plants with carbon dioxide management: Technical and economic optimization

    NASA Astrophysics Data System (ADS)

    Curletti, F.; Gandiglio, M.; Lanzini, A.; Santarelli, M.; Maréchal, F.

    2015-10-01

    This article investigates the techno-economic performance of large integrated biogas Solid Oxide Fuel Cell (SOFC) power plants. Both atmospheric and pressurized operation is analysed with CO2 vented or captured. The SOFC module produces a constant electrical power of 1 MWe. Sensitivity analysis and multi-objective optimization are the mathematical tools used to investigate the effects of Fuel Utilization (FU), SOFC operating temperature and pressure on the plant energy and economic performances. FU is the design variable that most affects the plant performance. Pressurized SOFC with hybridization with a gas turbine provides a notable boost in electrical efficiency. For most of the proposed plant configurations, the electrical efficiency ranges in the interval 50-62% (LHV biogas) when a trade-off of between energy and economic performances is applied based on Pareto charts obtained from multi-objective plant optimization. The hybrid SOFC is potentially able to reach an efficiency above 70% when FU is 90%. Carbon capture entails a penalty of more 10 percentage points in pressurized configurations mainly due to the extra energy burdens of captured CO2 pressurization and oxygen production and for the separate and different handling of the anode and cathode exhausts and power recovery from them.

  20. Study on the mechanism of diametral cladding strain and mixed-oxide fuel element breaching in slow-ramp extended overpower transients

    SciTech Connect

    Tomoyuki Uwaba; Seiichiro Maeda; Tomoyasu Mizuno; Melissa C. Teague

    2012-10-01

    Cladding strain caused by fuel/cladding mechanical interaction (FCMI) was evaluated for mixed-oxide fuel elements subjected to 70–90% slow-ramp extended overpower transient tests in the experimental breeder reactor II. Calculated transient-induced cladding strains were correlated with cumulative damage fractions (CDFs) using cladding strength correlations. In a breached high-smeared density solid fuel element with low strength cladding, cladding thermal creep strain was significantly increased to approximately half the transient-induced cladding strain that was considered to be caused by the tertiary creep when the CDF was close to the breach criterion (=1.0), with the remaining strain due to instantaneous plastic deformation. In low-smeared density annular fuel elements, FCMI load was significantly mitigated and resulted in little cladding strain. The CDFs of the annular fuel elements were lower than 0.01 at the end of the overpower transient, indicating a substantial margin to breach. A substantial margin to breach was also maintained in a high-smeared density fuel element with high strength cladding.

  1. Measurements of substrate oxidation using (13)CO 2-breath testing reveals shifts in fuel mix during starvation.

    PubMed

    McCue, Marshall D; Pollock, Erik D

    2013-12-01

    Most fasting animals are believed to sequentially switch from predominantly utilizing one metabolic substrate to another from carbohydrates, to lipids, then to proteins. The timing of these physiological transitions has been estimated using measures of substrate oxidation including changes in respiratory exchange ratios, blood metabolites, nitrogen excretion, or enzyme activities in tissues. Here, we demonstrate how (13)CO2-breath testing can be used to partition among the oxidation of distinct nutrient pools in the body (i.e., carbohydrates, lipids, and proteins) that have become artificially enriched in (13)C. Seventy-two Swiss Webster mice were raised to adulthood on diets supplemented with (13)C-1-L-leucine, (13)C-1-palmitic acid, (13)C-1-D-glucose, or no tracer. Mice were then fasted for 72 h during which [Formula: see text], [Formula: see text], δ(13)C of exhaled CO2, body temperature, body mass, and blood metabolites (i.e., glucose, ketone bodies, and triacylglycerols) were measured. The fasting mice exhibited reductions in body mass (29 %), body temperature (3.3 °C), minimum observed metabolic rates (24 %), and respiratory exchange ratio (0.18), as well as significant changes in blood metabolites; but these responses were not particularly indicative of changes in oxidative fuel mixture. Measurements of endogenous nutrient oxidation by way of (13)CO2-breath testing revealed a decrease in the rate of oxidation of carbohydrates from 61 to 10 % of the total energy expenditure during the first 6 h without food. This response was mirrored by a coincidental increase in rate of endogenous lipid oxidation from 18 to 64 %. A transient peak in carbohydrate oxidation occurred between 8 and 14 h, presumably during increased glycogen mobilization. A well-defined period of protein sparing between 8 and 12 h was observed where endogenous protein oxidation accounted for as little as 8 % of the total energy expenditure. Thereafter, protein oxidation continually

  2. Uranium plutonium oxide fuels. [LMFBR

    SciTech Connect

    Cox, C.M.; Leggett, R.D.; Weber, E.T.

    1981-01-01

    Uranium plutonium oxide is the principal fuel material for liquid metal fast breeder reactors (LMFBR's) throughout the world. Development of this material has been a reasonably straightforward evolution from the UO/sub 2/ used routinely in the light water reactor (LWR's); but, because of the lower neutron capture cross sections and much lower coolant pressures in the sodium cooled LMFBR's, the fuel is operated to much higher discharge exposures than that of a LWR. A typical LMFBR fuel assembly is shown. Depending on the required power output and the configuration of the reactor, some 70 to 400 such fuel assemblies are clustered to form the core. There is a wide variation in cross section and length of the assemblies where the increasing size reflects a chronological increase in plant size and power output as well as considerations of decreasing the net fuel cycle cost. Design and performance characteristics are described.

  3. ZERO EMISSION POWER PLANTS USING SOLID OXIDE FUEL CELLS AND OXYGEN TRANSPORT MEMBRANES

    SciTech Connect

    G. Maxwell Christie; Troy M. Raybold

    2003-06-10

    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.

  4. Effects of fuel processing methods on industrial scale biogas-fuelled solid oxide fuel cell system for operating in wastewater treatment plants

    NASA Astrophysics Data System (ADS)

    Farhad, Siamak; Yoo, Yeong; Hamdullahpur, Feridun

    The performance of three solid oxide fuel cell (SOFC) systems, fuelled by biogas produced through anaerobic digestion (AD) process, for heat and electricity generation in wastewater treatment plants (WWTPs) is studied. Each system has a different fuel processing method to prevent carbon deposition over the anode catalyst under biogas fuelling. Anode gas recirculation (AGR), steam reforming (SR), and partial oxidation (POX) are the methods employed in systems I-III, respectively. A planar SOFC stack used in these systems is based on the anode-supported cells with Ni-YSZ anode, YSZ electrolyte and YSZ-LSM cathode, operated at 800 °C. A computer code has been developed for the simulation of the planar SOFC in cell, stack and system levels and applied for the performance prediction of the SOFC systems. The key operational parameters affecting the performance of the SOFC systems are identified. The effect of these parameters on the electrical and CHP efficiencies, the generated electricity and heat, the total exergy destruction, and the number of cells in SOFC stack of the systems are studied. The results show that among the SOFC systems investigated in this study, the AGR and SR fuel processor-based systems with electrical efficiency of 45.1% and 43%, respectively, are suitable to be applied in WWTPs. If the entire biogas produced in a WWTP is used in the AGR or SR fuel processor-based SOFC system, the electricity and heat required to operate the WWTP can be completely self-supplied and the extra electricity generated can be sold to the electrical grid.

  5. Solid oxide fuel cell generator

    DOEpatents

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

    1993-11-02

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

  6. Solid oxide fuel cell generator

    DOEpatents

    Di Croce, A. Michael; Draper, Robert

    1993-11-02

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

  7. Optimal planning of co-firing alternative fuels with coal in a power plant by grey nonlinear mixed integer programming model.

    PubMed

    Ko, Andi Setiady; Chang, Ni-Bin

    2008-07-01

    Energy supply and use is of fundamental importance to society. Although the interactions between energy and environment were originally local in character, they have now widened to cover regional and global issues, such as acid rain and the greenhouse effect. It is for this reason that there is a need for covering the direct and indirect economic and environmental impacts of energy acquisition, transport, production and use. In this paper, particular attention is directed to ways of resolving conflict between economic and environmental goals by encouraging a power plant to consider co-firing biomass and refuse-derived fuel (RDF) with coal simultaneously. It aims at reducing the emission level of sulfur dioxide (SO(2)) in an uncertain environment, using the power plant in Michigan City, Indiana as an example. To assess the uncertainty by a comparative way both deterministic and grey nonlinear mixed integer programming (MIP) models were developed to minimize the net operating cost with respect to possible fuel combinations. It aims at generating the optimal portfolio of alternative fuels while maintaining the same electricity generation simultaneously. To ease the solution procedure stepwise relaxation algorithm was developed for solving the grey nonlinear MIP model. Breakeven alternative fuel value can be identified in the post-optimization stage for decision-making. Research findings show that the inclusion of RDF does not exhibit comparative advantage in terms of the net cost, albeit relatively lower air pollution impact. Yet it can be sustained by a charge system, subsidy program, or emission credit as the price of coal increases over time.

  8. Solid oxide fuel cell combined cycles

    SciTech Connect

    Bevc, F.P.; Lundberg, W.L.; Bachovchin, D.M.

    1996-12-31

    The integration of the solid oxide fuel cell and combustion turbine technologies can result in combined-cycle power plants, fueled with natural gas, that have high efficiencies and clean gaseous emissions. Results of a study are presented in which conceptual designs were developed for 3 power plants based upon such an integration, and ranging in rating from 3 to 10 MW net ac. The plant cycles are described and characteristics of key components summarized. Also, plant design-point efficiency estimates are presented as well as values of other plant performance parameters.

  9. Looking Northeast Along Hallway between Pellet Plant and Oxide Building, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Looking Northeast Along Hallway between Pellet Plant and Oxide Building, including Virgin Hopper Bins - Hematite Fuel Fabrication Facility, Pellet Plant, 3300 State Road P, Festus, Jefferson County, MO

  10. Solid-oxide fuel-cell performance

    SciTech Connect

    Fee, D.C.; Zwick, S.A.; Ackerman, J.P.

    1983-01-01

    Two models have been developed to describe the performance of solid-oxide fuel cells: (1) a cell model which calculates cell performance for various conditions of temperature, current density, and gas composition; and (2) a systems model which performs detailed heat and mass balances around each component in a power plant. The cell model provides insight into the performance tradeoffs in cell design. Further, the cell model provides the basis for predicting fuel cell performance in a power plant environment as necessary for the systems code. Using these two tools, analysis of an atmospheric pressure, natural gas fueled, internally reforming power plant confirms the simplicity and increased efficiency of a solid oxide fuel cell system compared to existing plants.

  11. Neutronics Benchmarks for the Utilization of Mixed-Oxide Fuel: Joint U.S./Russian Progress Report for Fiscal Year 1997 Volume 2-Calculations Performed in the United States

    SciTech Connect

    Primm III, RT

    2002-05-29

    This volume of the progress report provides documentation of reactor physics and criticality safety studies conducted in the US during fiscal year 1997 and sponsored by the Fissile Materials Disposition Program of the US Department of Energy. Descriptions of computational and experimental benchmarks for the verification and validation of computer programs for neutron physics analyses are included. All benchmarks include either plutonium, uranium, or mixed uranium and plutonium fuels. Calculated physics parameters are reported for all of the computational benchmarks and for those experimental benchmarks that the US and Russia mutually agreed in November 1996 were applicable to mixed-oxide fuel cycles for light-water reactors.

  12. RGA Analysis of a Solid Oxide Fuel Cell Gas Turbine Hybrid Plant

    SciTech Connect

    Tsai, Alex; Banta, Larry; Tucker, D.A.; Gemmen, R.S.

    2008-06-01

    This paper presents a Relative Gain Array (RGA) analysis of a simulated SOFC/Gas Turbine plant based on a multivariate empirical formulation of a 300kW hybrid system. The HyPer test facility at the National Energy Technology Laboratory, served as the test bed for deriving frequency response data and subsequent multivariable model of a direct fired, recuperated hybrid cycle plant. Through the modulation of various airflow bypass-valves, magnitude and phase data is used to formulate Transfer Function {TF} equations that describe input/output system interaction. A frequency dependent RGA calculation of the empirical Transfer Function matrix provides a means of quantifying the degree of coupling between system inputs and outputs for the configuration studied. Various input/output interaction time scales are obtained to identify frequencies where fully developed system coupling occur. Analysis of the RGA matrix leads to a better understanding of the inherent properties the hybrid configuration, and can serve as a validating tool to existing analytical RGA calculations of similar types of hybrids.

  13. Native plant growth promoting bacteria Bacillus thuringiensis and mixed or individual mycorrhizal species improved drought tolerance and oxidative metabolism in Lavandula dentata plants.

    PubMed

    Armada, E; Probanza, A; Roldán, A; Azcón, R

    2016-03-15

    This study evaluates the responses of Lavandula dentata under drought conditions to the inoculation with single autochthonous arbuscular mycorrhizal (AM) fungus (five fungal strains) or with their mixture and the effects of these inocula with a native Bacillus thuringiensis (endophytic bacteria). These microorganisms were drought tolerant and in general, increased plant growth and nutrition. Particularly, the AM fungal mixture and B. thuringiensis maximized plant biomass and compensated drought stress as values of antioxidant activities [superoxide dismutase (SOD), catalase (CAT) and ascorbate peroxidase APX)] shown. The AMF-bacteria interactions highly reduced the plant oxidative damage of lipids [malondialdehyde (MDA)] and increased the mycorrhizal development (mainly arbuscular formation representative of symbiotic functionality). These microbial interactions explain the highest potential of dually inoculated plants to tolerate drought stress. B. thuringiensis "in vitro" under osmotic stress does not reduce its PGPB (plant growth promoting bacteria) abilities as indole acetic acid (IAA) and ACC deaminase production and phosphate solubilization indicating its capacity to improve plant growth under stress conditions. Each one of the autochthonous fungal strains maintained their particular interaction with B. thuringiensis reflecting the diversity, intrinsic abilities and inherent compatibility of these microorganisms. In general, autochthonous AM fungal species and particularly their mixture with B. thuringiensis demonstrated their potential for protecting plants against drought and helping plants to thrive in semiarid ecosystems. PMID:26796423

  14. Native plant growth promoting bacteria Bacillus thuringiensis and mixed or individual mycorrhizal species improved drought tolerance and oxidative metabolism in Lavandula dentata plants.

    PubMed

    Armada, E; Probanza, A; Roldán, A; Azcón, R

    2016-03-15

    This study evaluates the responses of Lavandula dentata under drought conditions to the inoculation with single autochthonous arbuscular mycorrhizal (AM) fungus (five fungal strains) or with their mixture and the effects of these inocula with a native Bacillus thuringiensis (endophytic bacteria). These microorganisms were drought tolerant and in general, increased plant growth and nutrition. Particularly, the AM fungal mixture and B. thuringiensis maximized plant biomass and compensated drought stress as values of antioxidant activities [superoxide dismutase (SOD), catalase (CAT) and ascorbate peroxidase APX)] shown. The AMF-bacteria interactions highly reduced the plant oxidative damage of lipids [malondialdehyde (MDA)] and increased the mycorrhizal development (mainly arbuscular formation representative of symbiotic functionality). These microbial interactions explain the highest potential of dually inoculated plants to tolerate drought stress. B. thuringiensis "in vitro" under osmotic stress does not reduce its PGPB (plant growth promoting bacteria) abilities as indole acetic acid (IAA) and ACC deaminase production and phosphate solubilization indicating its capacity to improve plant growth under stress conditions. Each one of the autochthonous fungal strains maintained their particular interaction with B. thuringiensis reflecting the diversity, intrinsic abilities and inherent compatibility of these microorganisms. In general, autochthonous AM fungal species and particularly their mixture with B. thuringiensis demonstrated their potential for protecting plants against drought and helping plants to thrive in semiarid ecosystems.

  15. Solid oxide fuel cell generator

    DOEpatents

    Draper, Robert; George, Raymond A.; Shockling, Larry A.

    1993-01-01

    A solid oxide fuel cell generator has a pair of spaced apart tubesheets in a housing. At least two intermediate barrier walls are between the tubesheets and define a generator chamber between two intermediate buffer chambers. An array of fuel cells have tubes with open ends engaging the tubesheets. Tubular, axially elongated electrochemical cells are supported on the tubes in the generator chamber. Fuel gas and oxidant gas are preheated in the intermediate chambers by the gases flowing on the other side of the tubes. Gas leakage around the tubes through the tubesheets is permitted. The buffer chambers reentrain the leaked fuel gas for reintroduction to the generator chamber.

  16. Solid oxide fuel cell generator

    DOEpatents

    Draper, R.; George, R.A.; Shockling, L.A.

    1993-04-06

    A solid oxide fuel cell generator has a pair of spaced apart tubesheets in a housing. At least two intermediate barrier walls are between the tubesheets and define a generator chamber between two intermediate buffer chambers. An array of fuel cells have tubes with open ends engaging the tubesheets. Tubular, axially elongated electrochemical cells are supported on the tubes in the generator chamber. Fuel gas and oxidant gas are preheated in the intermediate chambers by the gases flowing on the other side of the tubes. Gas leakage around the tubes through the tubesheets is permitted. The buffer chambers reentrain the leaked fuel gas for reintroduction to the generator chamber.

  17. Advanced Recycling Core Accommodating Oxide Fuel and Metal Fuel for Closed Fuel Cycle

    NASA Astrophysics Data System (ADS)

    Ikeda, Kazumi; Maddox, James W.; Nakazato, Wataru; Kunishima, Shigeru

    This report presents a unique TRU burning core capable of accommodating oxide fuel and metal fuel and easy to change oxide core to metal core conforming to the design requirements. For the homogeneous oxide fueled core containing transuranics (TRU) fuel with 12% of the moderator pins, the results of calculation show the TRU conversion ratio (ratio of loss of TRU to loss of heavy metal) of 0.33 and the TRU burning capability (ratio of loss of TRU per electric generation) of 67 kg/TWeh. On the other hand, the calculations replacing from oxide fuel assemblies to metal fuel assemblies have indicated the TRU transmutation capability of 69 kg/TWeh with the TRU conversion ratio of 0.30. As the result of simulation calculations, three ordinary fuel exchanges transform the oxide equilibrium core to the full metal core by way of transitional cores, where the maximum linear heat rates are still equal to the metal equilibrium core or less. With this, the presented core concept is concluded that a full oxide core, a full metal core, mixed fueled cores can be materialized in the presented first unit of Advanced Recycling Reactor (ARR1).

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

    NASA Astrophysics Data System (ADS)

    Huang, Kevin

    2011-03-01

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

  19. Melvin Calvin: Fuels from Plants

    SciTech Connect

    Taylor, S.E.; Otvos, J.W.

    1998-11-24

    A logical extension of his early work on the path of carbon during photosynthesis, Calvin's studies on the production of hydrocarbons by plants introduced many in the scientific and agricultural worlds to the potential of renewable fuel and chemical feedstocks. He and his co-workers identified numerous candidate compounds from plants found in tropical and temperate climates from around the world. His travels and lectures concerning the development of alternative fuel supplies inspired laboratories worldwide to take up the investigation of plant-derived energy sources as an alternative to fossil fuels.

  20. Mixed waste paper to ethanol fuel

    SciTech Connect

    Not Available

    1991-01-01

    The objectives of this study were to evaluate the use of mixed waste paper for the production of ethanol fuels and to review the available conversion technologies, and assess developmental status, current and future cost of production and economics, and the market potential. This report is based on the results of literature reviews, telephone conversations, and interviews. Mixed waste paper samples from residential and commercial recycling programs and pulp mill sludge provided by Weyerhauser were analyzed to determine the potential ethanol yields. The markets for ethanol fuel and the economics of converting paper into ethanol were investigated.

  1. An experimental aluminum-fueled power plant

    NASA Astrophysics Data System (ADS)

    Vlaskin, M. S.; Shkolnikov, E. I.; Bersh, A. V.; Zhuk, A. Z.; Lisicyn, A. V.; Sorokovikov, A. I.; Pankina, Yu. V.

    2011-10-01

    An experimental co-generation power plant (CGPP-10) using aluminum micron powder (with average particle size up to 70 μm) as primary fuel and water as primary oxidant was developed and tested. Power plant can work in autonomous (unconnected from industrial network) nonstop regime producing hydrogen, electrical energy and heat. One of the key components of experimental plant is aluminum-water high-pressure reactor projected for hydrogen production rate of ∼10 nm3 h-1. Hydrogen from the reactor goes through condenser and dehumidifier and with -25 °C dew-point temperature enters into the air-hydrogen fuel cell 16 kW-battery. From 1 kg of aluminum the experimental plant produces 1 kWh of electrical energy and 5-7 kWh of heat. Power consumer gets about 10 kW of electrical power. Plant electrical and total efficiencies are 12% and 72%, respectively.

  2. Mixed Mode Fuel Injector And Injection System

    DOEpatents

    Stewart, Chris Lee; Tian, Ye; Wang, Lifeng; Shafer, Scott F.

    2005-12-27

    A fuel injector includes a homogenous charge nozzle outlet set and a conventional nozzle outlet set that are controlled respectively by first and second three way needle control valves. Each fuel injector includes first and second concentric needle valve members. One of the needle valve members moves to an open position for a homogenous charge injection event, while the other needle valve member moves to an open position for a conventional injection event. The fuel injector has the ability to operate in a homogenous charge mode with a homogenous charge spray pattern, a conventional mode with a conventional spray pattern or a mixed mode.

  3. Optical and electrical studies of cerium mixed oxides

    SciTech Connect

    Sherly, T. R.; Raveendran, R.

    2014-10-15

    The fast development in nanotechnology makes enthusiastic interest in developing nanomaterials having tailor made properties. Cerium mixed oxide materials have received great attention due to their UV absorption property, high reactivity, stability at high temperature, good electrical property etc and these materials find wide applications in solid oxide fuel cells, solar control films, cosmetics, display units, gas sensors etc. In this study cerium mixed oxide compounds were prepared by co-precipitation method. All the samples were doped with Zn (II) and Fe (II). Preliminary characterizations such as XRD, SEM / EDS, TEM were done. UV - Vis, Diffuse reflectance, PL, FT-IR, Raman and ac conductivity studies of the samples were performed.

  4. Neat methanol fuel cell power plant

    NASA Astrophysics Data System (ADS)

    Abens, S.; Farooque, M.

    1985-12-01

    Attention is given to a fuel cell development effort which has been directed, by ease-of-supply, low weight, and low volume criteria toward the use of undiluted methanol. Partial oxidation and internal water recovery concepts are incorporated, allowing the onboard dilution of methanol fuel through mixing with exhaust-recovered water. This scheme is successfully demonstrated for the case of a 3 kW unit employing commercial cross flow heat exchangers, as well as for a 5 kW reformer flue exhaust water recovery design with U.S. Air force baseload stationary applications. The USAF powerplant has an overall thermal efficiency of 32 percent at rated load.

  5. Heating subsurface formations by oxidizing fuel on a fuel carrier

    SciTech Connect

    Costello, Michael; Vinegar, Harold J.

    2012-10-02

    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.

  6. Metabolic fuels: regulating fluxes to select mix.

    PubMed

    Weber, Jean-Michel

    2011-01-15

    Animals must regulate the fluxes of multiple fuels to support changing metabolic rates that result from variation in physiological circumstances. The aim of fuel selection strategies is to exploit the advantages of individual substrates while minimizing the impact of disadvantages. All exercising mammals share a general pattern of fuel selection: at the same %V(O(2,max)) they oxidize the same ratio of lipids to carbohydrates. However, highly aerobic species rely more on intramuscular fuels because energy supply from the circulation is constrained by trans-sarcolemmal transfer. Fuel selection is performed by recruiting different muscles, different fibers within the same muscles or different pathways within the same fibers. Electromyographic analyses show that shivering humans can modulate carbohydrate oxidation either through the selective recruitment of type II fibers within the same muscles or by regulating pathway recruitment within type I fibers. The selection patterns of shivering and exercise are different: at the same %V(O(2,max)), a muscle producing only heat (shivering) or significant movement (exercise) strikes a different balance between lipid and carbohydrate oxidation. Long-distance migrants provide an excellent model to characterize how to increase maximal substrate fluxes. High lipid fluxes are achieved through the coordinated upregulation of mobilization, transport and oxidation by activating enzymes, lipid-solubilizing proteins and membrane transporters. These endurance athletes support record lipolytic rates in adipocytes, use lipoprotein shuttles to accelerate transport and show increased capacity for lipid oxidation in muscle mitochondria. Some migrant birds use dietary omega-3 fatty acids as performance-enhancing agents to boost their ability to process lipids. These dietary fatty acids become incorporated in membrane phospholipids and bind to peroxisome proliferator-activated receptors to activate membrane proteins and modify gene expression.

  7. Conceptual study and analysis of hydrogen fueled power plants

    SciTech Connect

    Wang, X; Zhang, S.; Zhao, L.; Cai, R.

    1998-07-01

    To decrease pollution of the environment caused by coal fired plants in China, it is important to develop clean fuel and advanced energy systems. As a kind of efficient, clean, renewable fuel, hydrogen is a prospective alternative to traditional fossil fuel if the problem about hydrogen production and safety can be solved thoroughly. In this paper, several kinds of power generating systems using hydrogen energy have been put forward, analyzed, and discussed. One way of hydrogen utilization is turbine power plant based on stoichiometric reaction of hydrogen and pure oxygen or air, such as the mixing H{sub 2}/O{sub 2} combined cycle. Because the reaction which takes place in the combustor is stoichiometric, the only product is water. So the expansion process of working fluid may include part of the bottoming cycle, which results in a higher efficiency than conventional combined cycle. A new cycle--advanced H{sub 2}/O{sub 2} mixing combined cycle (AMC) is put forward in this paper. The main difference between it and the old one are the adoption of double reheat and semi-closed steam bottoming cycle. Theoretical analysis notes that the efficiency due to the addition of bottoming cycle and reheat is about 6 percentage points higher than the original mixing combined cycle. An alternative closed combined cycle (ACC) developed from the basic closed combined cycle is based on stoichiometric reaction of hydrogen and air. The main characteristic of it is the application of gas recirculation and water reinjection. Compared with the original closed cycle, the emission of this new one is low. Fuel cells which are expected to be used as on site power generating devices in the future provide a new way to hydrogen utilization. A hybrid cycle composed of solid oxide fuel cell, gas turbine, steam turbine and chemical looping combustor (FCC) is put forward in this paper. The key difference between other SOFC systems and this one lies in that in this system, fuel and oxidizer of fuel

  8. Purge gas recovery of ammonia synthesis plant by integrated configuration of catalytic hydrogen-permselective membrane reactor and solid oxide fuel cell as a novel technology

    NASA Astrophysics Data System (ADS)

    Siavashi, Fakhteh; Saidi, Majid; Rahimpour, Mohammad Reza

    2014-12-01

    The purge gas emission of ammonia synthesis plant which contains hazardous components is one of the major sources of environmental pollution. Using integrated configuration of catalytic hydrogen-permselective membrane reactor and solid oxide fuel cell (SOFC) system is a new approach which has a great impact to reduce the pollutant emission. By application of this method, not only emission of ammonia and methane in the atmosphere is prevented, hydrogen is produced through the methane steam reforming and ammonia decomposition reactions that take place simultaneously in a catalytic membrane reactor. The pure generated hydrogen by recovery of the purge gas in the Pd-Ag membrane reactor is used as a feed of SOFC. Since water is the only byproduct of the electrochemical reaction in the SOFC, it is recycled to the reactor for providing the required water of the reforming reaction. Performance investigation of the reactor represents that the rate of hydrogen permeation increases with enhancing the reactor temperature and pressure. Also modeling results indicate that the SOFC performance improves with increasing the temperature and fuel utilization ratio. The generated power by recovery of the purging gas stream of ammonia synthesis plant in the Razi petrochemical complex is about 8 MW.

  9. Mixed fuel composition. [fuel oil, coal powder, and polymer

    SciTech Connect

    Igarashi, T.; Ukigai, T.; Yamamura, M.

    1982-07-13

    A mixed fuel composition comprises (A) a fuel oil, (B) a coal powder having an (H)/(C) ratio according to the coalification band method in the range of 0.4-0.75 and an (O)/(C) ratio in the range of 0.09-0.18 and (C) a partially amidated copolymer obtained by reacting a copolymer of a polymerizable, unsaturated hydrocarbon and maleic anhydride with an aliphatic amine of 2-36 carbon-atoms or a salt thereof as a stabilizer.

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

    SciTech Connect

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

    2010-01-01

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

  11. Mixed oxide nanoparticles and method of making

    DOEpatents

    Lauf, Robert J.; Phelps, Tommy J.; Zhang, Chuanlun; Roh, Yul

    2002-09-03

    Methods and apparatus for producing mixed oxide nanoparticulates are disclosed. Selected thermophilic bacteria cultured with suitable reducible metals in the presence of an electron donor may be cultured under conditions that reduce at least one metal to form a doped crystal or mixed oxide composition. The bacteria will form nanoparticles outside the cell, allowing easy recovery. Selection of metals depends on the redox potentials of the reducing agents added to the culture. Typically hydrogen or glucose are used as electron donors.

  12. Reduction of spalling in mixed metal oxide desulfurization sorbents by addition of a large promoter metal oxide

    DOEpatents

    Poston, James A.

    1997-01-01

    Mixed metal oxide pellets for removing hydrogen sulfide from fuel gas mixes derived from coal are stabilized for operation over repeated cycles of desulfurization and regeneration reactions by addition of a large promoter metal oxide such as lanthanum trioxide. The pellets, which may be principally made up of a mixed metal oxide such as zinc titanate, exhibit physical stability and lack of spalling or decrepitation over repeated cycles without loss of reactivity. The lanthanum oxide is mixed with pellet-forming components in an amount of 1 to 10 weight percent.

  13. Reduction of spalling in mixed metal oxide desulfurization sorbents by addition of a large promoter metal oxide

    DOEpatents

    Poston, J.A.

    1997-12-02

    Mixed metal oxide pellets for removing hydrogen sulfide from fuel gas mixes derived from coal are stabilized for operation over repeated cycles of desulfurization and regeneration reactions by addition of a large promoter metal oxide such as lanthanum trioxide. The pellets, which may be principally made up of a mixed metal oxide such as zinc titanate, exhibit physical stability and lack of spalling or decrepitation over repeated cycles without loss of reactivity. The lanthanum oxide is mixed with pellet-forming components in an amount of 1 to 10 weight percent.

  14. Mixing enhancement in a scramjet combustor using fuel jet injection swirl

    NASA Astrophysics Data System (ADS)

    Flesberg, Sonja M.

    The scramjet engine has proven to be a viable means of powering a hypersonic vehicle, especially after successful flights of the X-51 WaveRider and various Hy-SHOT test vehicles. The major challenge associated with operating a scramjet engine is the short residence time of the fuel and oxidizer in the combustor. The fuel and oxidizer have only milliseconds to mix, ignite and combust in the combustion chamber. Combustion cannot occur until the fuel and oxidizer are mixed on a molecular level. Therefore the improvement of mixing is of utmost interest since this can increase combustion efficiency. This study investigated mixing enhancement of fuel and oxidizer within the combustion chamber of a scramjet by introducing swirl to the fuel jet. The investigation was accomplished with numerical simulations using STAR-CCM+ computational fluid dynamic software. The geometry of the University of Virginia Supersonic Combustion Facility was used to model the isolator, combustor and nozzle of a scramjet engine for simulation purposes. Experimental data from previous research at the facility was used to verify the simulation model before investigating the effect of fuel jet swirl on mixing. The model used coaxial fuel jet with a swirling annular jet. Single coaxial fuel jet and dual coaxial fuel jet configurations were simulated for the investigation. The coaxial fuel jets were modelled with a swirling annular jet and non-swirling core jet. Numerical analysis showed that fuel jet swirl not only increased mixing and entrainment of the fuel with the oxidizer but the mixing occurred further upstream than without fuel jet swirl. The burning efficiency was calculated for the all the configurations. An increase in burning efficiency indicated an increase in the mixing of H2 with O2. In the case of the single fuel jet models, the maximum burning efficiency increase due to fuel injection jet swirl was 23.3%. The research also investigated the possibility that interaction between two

  15. Intermediate temperature solid oxide fuel cells.

    PubMed

    Brett, Daniel J L; Atkinson, Alan; Brandon, Nigel P; Skinner, Stephen J

    2008-08-01

    High temperature solid oxide fuel cells (SOFCs), typified by developers such as Siemens Westinghouse and Rolls-Royce, operate in the temperature region of 850-1000 degrees C. For such systems, very high efficiencies can be achieved from integration with gas turbines for large-scale stationary applications. However, high temperature operation means that the components of the stack need to be predominantly ceramic and high temperature metal alloys are needed for many balance-of-plant components. For smaller scale applications, where integration with a heat engine is not appropriate, there is a trend to move to lower temperatures of operation, into the so-called intermediate temperature (IT) range of 500-750 degrees C. This expands the choice of materials and stack geometries that can be used, offering reduced system cost and, in principle, reducing the corrosion rate of stack and system components. This review introduces the IT-SOFC and explains the advantages of operation in this temperature regime. The main advances made in materials chemistry that have made IT operation possible are described and some of the engineering issues and the new opportunities that reduced temperature operation affords are discussed. This tutorial review examines the advances being made in materials and engineering that are allowing solid oxide fuel cells to operate at lower temperature. The challenges and advantages of operating in the so-called 'intermediate temperature' range of 500-750 degrees C are discussed and the opportunities for applications not traditionally associated with solid oxide fuel cells are highlighted. This article serves as an introduction for scientists and engineers interested in intermediate temperature solid oxide fuel cells and the challenges and opportunities of reduced temperature operation. PMID:18648682

  16. Solid oxidized fuel cells seals leakage setup and testing

    NASA Technical Reports Server (NTRS)

    Bastrzyk, Marta B.

    2004-01-01

    As the world s reserves of fossil fuels are depleted, the U.S. Government, as well as other countries and private industries, is researching solutions for obtaining power, answers that would be more efficient and environmentally friendly. For a long time engineers have been trying to obtain the benefits of clean electric power without heavy batteries or pollution-producing engines. While some of the inventions proved to be effective (i.e. solar panels or windmills) their applications are limited due to dependency on the energy source (i.e. sun or wind). Currently, as energy concerns increase, research is being carried out on the development of a Solid Oxide Fuel Cell (SOFC). The United States government is taking a proactive role in expanding the technology through the Solid State Energy Conversion Alliance (SECA) Program, which is coordinated by the Department of Energy. into an electrical energy. This occurs by the means of natural tendency of oxygen and hydrogen to chemically react. While controlling the process, it is possible to harvest the energy given off by the reaction. SOFCs use currently available fossil fuels and convert a variety of those fuels with very high efficiency (about 40% more efficient than modem thermal power plants). At the same time they are almost entirely nonpolluting and due to their size they can be placed in remote areas. The main fields where the application of the fuel cells appears to be the most useful for are stationary energy sources, transportation, and military applications. structure and materials must be resolved. All the components must be operational in harsh environments including temperatures reaching 800 C and cyclic thermal- mechanical loading. Under these conditions, the main concern is the requirement for hermetic seals to: (1) prevent mixing of the fuel and oxidant within the stack, (2) prevent parasitic leakage of the fuel from the stack, (3) prevent contamination of the anode by air leaking into the stack, (4

  17. Catalytic iron oxide for lime regeneration in carbonaceous fuel combustion

    DOEpatents

    Shen, Ming-Shing; Yang, Ralph T.

    1980-01-01

    Lime utilization for sulfurous oxides absorption in fluidized combustion of carbonaceous fuels is improved by impregnation of porous lime particulates with iron oxide. The impregnation is achieved by spraying an aqueous solution of mixed iron sulfate and sulfite on the limestone before transfer to the fluidized bed combustor, whereby the iron compounds react with the limestone substrate to form iron oxide at the limestone surface. It is found that iron oxide present in the spent limestone acts as a catalyst to regenerate the spent limestone in a reducing environment. With only small quantities of iron oxide the calcium can be recycled at a significantly increased rate.

  18. Catalytic iron oxide for lime regeneration in carbonaceous fuel combustion

    SciTech Connect

    Shen, M.; Yang, R.T.

    1980-09-30

    Lime utilization for sulfurous oxides absorption in fluidized combustion of carbonaceous fuels is improved by impregnation of porous lime particulates with iron oxide. The impregnation is achieved by spraying an aqueous solution of mixed iron sulfate and sulfite on the limestone before transfer to the fluidized bed combustor, whereby the iron compounds react with the limestone substrate to form iron oxide at the limestone surface. It is found that iron oxide present in the spent limestone acts as a catalyst to regenerate the spent limestone in a reducing environment. With only small quantities of iron oxide the calcium can be recycled at a significantly increased rate.

  19. Fuel neutralization by ozone oxidation

    NASA Technical Reports Server (NTRS)

    Swartz, A. B.; Agthe, R. E.; Smith, I. D.; Mulholland, J. P.

    1988-01-01

    The viability of a hazardous waste disposal system based on ozone oxidation of hydrazine fuels at low aqueous concentrations in the presence of ultraviolet light (UV at 2.537 x 10(exp -7) m or 8.324 x 10(exp -7) ft) excitation was investigated. Important parameters investigated include temperature, solution pH, and ultraviolet light power. Statistically relevant experimentation was done to estimate main factor effects on performance. The best available chemical analysis technology was used to evaluate the performance of the system.

  20. Syngas Conversion to Hydrocarbon Fuels through Mixed Alcohol Intermediates

    SciTech Connect

    Dagle, Robert A.; Lebarbier, Vanessa M.; Albrecht, Karl O.; Li, Jinjing; Taylor, Charles E.; Bao, Xinhe; Wang, Yong

    2013-05-13

    Synthesis gas (syngas) can be used to synthesize a variety of fuels and chemicals. Domestic transportation and military operational interests have driven continued focus on domestic syngas-based fuels production. Liquid transportation fuels may be made from syngas via four basic processes: 1) higher alcohols, 2) Fischer-Tropsch (FT), 3) methanol-to-gasoline (MTG), and 4) methanol-to-olefins (MTO) and olefins-to-gasoline/distillate (MOGD). Compared to FT and higher alcohols, MTG and MTO-MOGD have received less attention in recent years. Due to the high capital cost of these synthetic fuel plants, the production cost of the finished fuel cannot compete with petroleum-derived fuel. Pacific Northwest National Laboratory has recently evaluated one way to potentially reduce capital cost and overall production cost for MTG by combining the methanol and MTG syntheses in a single reactor. The concept consists of mixing the conventional MTG catalyst (i.e. HZSM-5) with an alcohol synthesis catalyst. It was found that a methanol synthesis catalyst, stable at high temperature (i.e. Pd/ZnO/Al2O3) [1], when mixed with ZSM-5, was active for syngas conversion. Relatively high syngas conversion can be achieved as the equilibrium-driven conversion limitations for methanol and dimethyl ether are removed as they are intermediates to the final hydrocarbon product. However, selectivity control was difficult to achieve as formation of undesirable durene and light hydrocarbons was problematic [2]. The objective of the present study was thus to evaluate other potential composite catalyst systems and optimize the reactions conditions for the conversion of syngas to hydrocarbon fuels, through the use of mixed alcohol intermediates. Mixed alcohols are of interest as they have recently been reported to produce higher yields of gasoline compared to methanol [3]. 1. Lebarbier, V.M., Dagle, R.A., Kovarik, L., Lizarazo-Adarme, J.A., King, D.L., Palo, D.R., Catalyst Science & Technology, 2012, 2

  1. Nondestructive assay confirmatory assessment experiments: mixed oxide

    SciTech Connect

    Lemming, J.F.

    1980-04-30

    The confirmatory assessment experiments demonstrate traceable nondestructive assay (NDA) measurements of plutonium in mixed oxide powder using commercially available spontaneous-fission assay systems. The experiments illustrate two major concepts: the production of calibration materials using calorimetric assay, and the use of paired measurements for measurement assurance. Two batches of well-characterized mixed oxide powder were used to establish the random and systematic error components. The major components of an NDA measurement assurance technique to establish and maintain traceability are identified and their functions are demonstrated. 20 refs., 10 figs., 10 tabs.

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

    NASA Astrophysics Data System (ADS)

    Lin, Jiefeng

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

  3. Gasoline-fueled solid oxide fuel cell using MoO2-Based Anode

    NASA Astrophysics Data System (ADS)

    Hou, Xiaoxue; Marin-Flores, Oscar; Kwon, Byeong Wan; Kim, Jinsoo; Norton, M. Grant; Ha, Su

    2014-12-01

    This short communication describes the performance of a solid oxide fuel cell (SOFC) fueled by directly feeding premium gasoline to the anode without using external reforming. The novel component of the fuel cell that enables such operation is the mixed conductivity of MoO2-based anode. Using this anode, a fuel cell demonstrating a maximum power density of 31 mW/cm2 at 0.45 V was successfully fabricated. Over a 24 h period of operation, the open cell voltage remained stable at ∼0.92 V. Scanning electron microscopy (SEM) examination of the anode surface pre- and post-testing showed no evidence of coking.

  4. Process for etching mixed metal oxides

    DOEpatents

    Ashby, C.I.H.; Ginley, D.S.

    1994-10-18

    An etching process is described using dicarboxylic and tricarboxylic acids as chelating etchants for mixed metal oxide films such as high temperature superconductors and ferroelectric materials. Undesirable differential etching rates between different metal oxides are avoided by selection of the proper acid or combination of acids. Feature sizes below one micron, excellent quality vertical edges, and film thicknesses in the 100 Angstrom range may be achieved by this method. 1 fig.

  5. Process for etching mixed metal oxides

    DOEpatents

    Ashby, Carol I. H.; Ginley, David S.

    1994-01-01

    An etching process using dicarboxylic and tricarboxylic acids as chelating etchants for mixed metal oxide films such as high temperature superconductors and ferroelectric materials. Undesirable differential etching rates between different metal oxides are avoided by selection of the proper acid or combination of acids. Feature sizes below one micron, excellent quality vertical edges, and film thicknesses in the 100 Angstom range may be achieved by this method.

  6. Mixed waste paper as a fuel

    SciTech Connect

    Kersletter, J.D.; Lyons, J.K. )

    1991-10-01

    A successful recycling program requires several components: education and promotion, convenient collection service, and most importantly, a market for collected materials. In Washington state, domestic markets currently have, or are building, the capacity to use most of the glass, newsprint, aluminum, tin cans, and corrugated materials that are collected. Unfortunately, markets for mixed waste paper (MWP), a major component of the state's solid waste stream, have been slow to develop and are unable to absorb the tremendous volumes of material generated. The American Paper Stock Institute classifies MWP as low grade paper such as magazines, books, scrap paper, non-corrugated cardboard (boxboard/chipboard), and construction paper. When viewed as part of a curbside collection program MWP consists primarily of catalogs, binder paper, magazines, brochures, junk mail, cereal boxes, and other household packaging items. A comprehensive analysis of Washington State's solid waste stream showed that during 1988, Washington citizens generated approximately 460,000 tons of mixed waste paper. No small amount, this is equivalent to more than 10% of the total solid waste generated in the state, and is expected to increase. Current projections of MWP generation rates indicated that Washington citizens could discard as much as 960,000 tons of MWP by the year 2010 making it one of the single largest components of the state's solid waste stream. This paper reports on the use of MWP as fuel source.

  7. ZPR-6 assembly 7 high {sup 240} PU core : a cylindrical assemby with mixed (PU, U)-oxide fuel and a central high {sup 240} PU zone.

    SciTech Connect

    Lell, R. M.; Schaefer, R. W.; McKnight, R. D.; Tsiboulia, A.; Rozhikhin, Y.; Nuclear Engineering Division; Inst. of Physics and Power Engineering

    2007-10-01

    Over a period of 30 years more than a hundred Zero Power Reactor (ZPR) critical assemblies were constructed at Argonne National Laboratory. The ZPR facilities, ZPR-3, ZPR-6, ZPR-9 and ZPPR, were all fast critical assembly facilities. The ZPR critical assemblies were constructed to support fast reactor development, but data from some of these assemblies are also well suited to form the basis for criticality safety benchmarks. Of the three classes of ZPR assemblies, engineering mockups, engineering benchmarks and physics benchmarks, the last group tends to be most useful for criticality safety. Because physics benchmarks were designed to test fast reactor physics data and methods, they were as simple as possible in geometry and composition. The principal fissile species was {sup 235}U or {sup 239}Pu. Fuel enrichments ranged from 9% to 95%. Often there were only one or two main core diluent materials, such as aluminum, graphite, iron, sodium or stainless steel. The cores were reflected (and insulated from room return effects) by one or two layers of materials such as depleted uranium, lead or stainless steel. Despite their more complex nature, a small number of assemblies from the other two classes would make useful criticality safety benchmarks because they have features related to criticality safety issues, such as reflection by soil-like material. The term 'benchmark' in a ZPR program connotes a particularly simple loading aimed at gaining basic reactor physics insight, as opposed to studying a reactor design. In fact, the ZPR-6/7 Benchmark Assembly (Reference 1) had a very simple core unit cell assembled from plates of depleted uranium, sodium, iron oxide, U3O8, and plutonium. The ZPR-6/7 core cell-average composition is typical of the interior region of liquid-metal fast breeder reactors (LMFBRs) of the era. It was one part of the Demonstration Reactor Benchmark Program,a which provided integral experiments characterizing the important features of demonstration

  8. Solid oxide fuel cell with monolithic core

    DOEpatents

    McPheeters, Charles C.; Mrazek, Franklin C.

    1988-01-01

    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.

  9. Solid oxide fuel cell with monolithic core

    DOEpatents

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

    1988-08-02

    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.

  10. Effects of mixing system and pilot fuel quality on diesel-biogas dual fuel engine performance.

    PubMed

    Bedoya, Iván Darío; Arrieta, Andrés Amell; Cadavid, Francisco Javier

    2009-12-01

    This paper describes results obtained from CI engine performance running on dual fuel mode at fixed engine speed and four loads, varying the mixing system and pilot fuel quality, associated with fuel composition and cetane number. The experiments were carried out on a power generation diesel engine at 1500 m above sea level, with simulated biogas (60% CH(4)-40% CO(2)) as primary fuel, and diesel and palm oil biodiesel as pilot fuels. Dual fuel engine performance using a naturally aspirated mixing system and diesel as pilot fuel was compared with engine performance attained with a supercharged mixing system and biodiesel as pilot fuel. For all loads evaluated, was possible to achieve full diesel substitution using biogas and biodiesel as power sources. Using the supercharged mixing system combined with biodiesel as pilot fuel, thermal efficiency and substitution of pilot fuel were increased, whereas methane and carbon monoxide emissions were reduced.

  11. Effects of mixing system and pilot fuel quality on diesel-biogas dual fuel engine performance.

    PubMed

    Bedoya, Iván Darío; Arrieta, Andrés Amell; Cadavid, Francisco Javier

    2009-12-01

    This paper describes results obtained from CI engine performance running on dual fuel mode at fixed engine speed and four loads, varying the mixing system and pilot fuel quality, associated with fuel composition and cetane number. The experiments were carried out on a power generation diesel engine at 1500 m above sea level, with simulated biogas (60% CH(4)-40% CO(2)) as primary fuel, and diesel and palm oil biodiesel as pilot fuels. Dual fuel engine performance using a naturally aspirated mixing system and diesel as pilot fuel was compared with engine performance attained with a supercharged mixing system and biodiesel as pilot fuel. For all loads evaluated, was possible to achieve full diesel substitution using biogas and biodiesel as power sources. Using the supercharged mixing system combined with biodiesel as pilot fuel, thermal efficiency and substitution of pilot fuel were increased, whereas methane and carbon monoxide emissions were reduced. PMID:19683439

  12. Analysis of mixing zone length using methane as fuel

    SciTech Connect

    Brasoveanu, D.; Gupta, A.K.

    1998-07-01

    The distributions of pressure, temperature and velocity, and correlation between radial and axial gradients of fuel mass fraction in an axisymmetric combustor are examined. A model for methane-air mixing in non-flammable mixtures, based on the ideal gas law and the equation of continuity, is described. High axial gradients of fuel mass fraction are required to produce a short mixing zone. Results show that high pressures and temperatures reduce the axial gradients of fuel, while high gradients of pressure and temperature can reduce the length of the mixing zone. High radial gradients of fuel mass fraction in conjunction with a large ratio of radial and axial velocity also shorten the mixing. Mixing is enhanced most by velocity divergence and temperature gradients. Analysis of the length of the mixing zone provides guidelines for the development of compact, high intensity, high efficiency and low emission combustors.

  13. Anode materials for sour natural gas solid oxide fuel cells

    NASA Astrophysics Data System (ADS)

    Danilovic, Nemanja

    Novel anode catalysts have been developed for sour natural gas solid oxide fuel cell (SOFC) applications. Sour natural gas comprises light hydrocarbons, and typically also contains H2S. An alternative fuel SOFC that operates directly on sour natural gas would reduce the overall cost of plant construction and operation for fuel cell power generation. The anode for such a fuel cell must have good catalytic and electrocatalytic activity for hydrocarbon conversion, sulfur-tolerance, resistance to coking, and good electronic and ionic conductivity. The catalytic activity and stability of ABO3 (A= La, Ce and/or Sr, B=Cr and one or more of Ti, V, Cr, Fe, Mn, or Co) perovskites as SOFC anode materials depends on both A and B, and are modified by substituents. The materials have been prepared by both solid state and wet-chemical methods. The physical and chemical characteristics of the materials have been fully characterized using electron microscopy, XRD, calorimetry, dilatometry, particle size and area, using XPS and TGA-DSC-MS. Electrochemical performance was determined using potentiodynamic and potentiostatic cell testing, electrochemical impedance analysis, and conductivity measurements. Neither Ce0.9Sr0.1VO3 nor Ce0.9 Sr0.1Cr0.5V0.5O3 was an active anode for oxidation of H2 and CH4 fuels. However, active catalysts comprising Ce0:9Sr0:1V(O,S)3 and Ce0.9Sr 0.1Cr0.5V0.5(O,S)3 were formed when small concentrations of H2S were present in the fuels. The oxysulfides formed in-situ were very active for conversion of H2S. The maximum performance improved from 50 mW cm-2 to 85 mW cm -2 in 0.5% H2S/CH4 at 850°C with partial substitution of V by Cr in Ce0.9Sr0.1V(O,S)3. Selective conversion of H2S offers potential for sweetening of sour gas without affecting the hydrocarbons. Perovskites La0.75Sr0.25Cr0.5X 0.5O3--delta, (henceforth referred to as LSCX, X=Ti, Mn, Fe, Co) are active for conversion of H2, CH4 and 0.5% H2S/CH4. The order of activity in the different fuels depends on

  14. Yttria-stabilized zirconia solid oxide electrolyte fuel cells: Monolithic solid oxide fuel cells

    NASA Astrophysics Data System (ADS)

    1990-10-01

    The monolithic solid oxide fuel cell (MSOFC) is currently under development for a variety of applications including coal-based power generation. The MSOFC is a design concept that places the thin components of a solid oxide fuel cell in lightweight, compact, corrugated structure, and so achieves high efficiency and excellent performance simultaneously with high power density. The MSOFC can be integrated with coal gasification plants and is expected to have high overall efficiency in the conversion of the chemical energy of coal to electrical energy. This report describes work aimed at: (1) assessing manufacturing costs for the MSOFC and system costs for a coal-based plant; (2) modifying electrodes and electrode/electrolyte interfaces to improve the electrochemical performance of the MSOFC; and (3) testing the performance of the MSOFC on hydrogen and simulated coal gas. Manufacturing costs for both the coflow and crossflow MSOFC's were assessed based on the fabrication flow charts developed by direct scaleup of tape calendering and other laboratory processes. Integrated coal-based MSOFC systems were investigated to determine capital costs and costs of electricity. Design criteria were established for a coal-fueled 200-Mw power plant. Four plant arrangements were evaluated, and plant performance was analyzed. Interfacial modification involved modification of electrodes and electrode/electrolyte interfaces to improve the MSOFC electrochemical performance. Work in the cathode and cathode/electrolyte interface was concentrated on modification of electrode porosity, electrode morphology, electrode material, and interfacial bonding. Modifications of the anode and anode/electrolyte interface included the use of additives and improvement of nickel distribution. Single cells have been tested for their electrochemical performance. Performance data were typically obtained with humidified H2 or simulated coal gas and air or oxygen.

  15. Jet fuel based high pressure solid oxide fuel cell system

    NASA Technical Reports Server (NTRS)

    Gummalla, Mallika (Inventor); Yamanis, Jean (Inventor); Olsommer, Benoit (Inventor); Dardas, Zissis (Inventor); Bayt, Robert (Inventor); Srinivasan, Hari (Inventor); Dasgupta, Arindam (Inventor); Hardin, Larry (Inventor)

    2013-01-01

    A power system for an aircraft includes a solid oxide fuel cell system which generates electric power for the aircraft and an exhaust stream; and a heat exchanger for transferring heat from the exhaust stream of the solid oxide fuel cell to a heat requiring system or component of the aircraft. The heat can be transferred to fuel for the primary engine of the aircraft. Further, the same fuel can be used to power both the primary engine and the SOFC. A heat exchanger is positioned to cool reformate before feeding to the fuel cell. SOFC exhaust is treated and used as inerting gas. Finally, oxidant to the SOFC can be obtained from the aircraft cabin, or exterior, or both.

  16. Jet Fuel Based High Pressure Solid Oxide Fuel Cell System

    NASA Technical Reports Server (NTRS)

    Gummalla, Mallika (Inventor); Yamanis, Jean (Inventor); Olsommer, Benoit (Inventor); Dardas, Zissis (Inventor); Bayt, Robert (Inventor); Srinivasan, Hari (Inventor); Dasgupta, Arindam (Inventor); Hardin, Larry (Inventor)

    2015-01-01

    A power system for an aircraft includes a solid oxide fuel cell system which generates electric power for the aircraft and an exhaust stream; and a heat exchanger for transferring heat from the exhaust stream of the solid oxide fuel cell to a heat requiring system or component of the aircraft. The heat can be transferred to fuel for the primary engine of the aircraft. Further, the same fuel can be used to power both the primary engine and the SOFC. A heat exchanger is positioned to cool reformate before feeding to the fuel cell. SOFC exhaust is treated and used as inerting gas. Finally, oxidant to the SOFC can be obtained from the aircraft cabin, or exterior, or both.

  17. [Nitric oxide production in plants].

    PubMed

    Małolepsza, Urszula

    2007-01-01

    There are still many controversial observations and opinions on the cellular/subcellular localization and sources of endogenous nitric oxide synthesis in plant cells. NO can be produced in plants by non-enzymatic and enzymatic systems depending on plant species, organ or tissue as well as on physiological state of the plant and changing environmental conditions. The best documented reactions in plant that contribute to NO production are NO production from nitrite as a substrate by cytosolic (cNR) and membrane bound (PM-NR) nitrate reductases (NR), and NO production by several arginine-dependent nitric oxide synthase-like activities (NOS). The latest papers indicate that mitochondria are an important source of arginine- and nitrite-dependent NO production in plants. There are other potential enzymatic sources of NO in plants including xanthine oxidoreductase, peroxidase, cytochrome P450. PMID:18399354

  18. Nanocrystalline cerium oxide materials for solid fuel cell systems

    SciTech Connect

    Brinkman, Kyle S

    2015-05-05

    Disclosed are solid fuel cells, including solid oxide fuel cells and PEM fuel cells that include nanocrystalline cerium oxide materials as a component of the fuel cells. A solid oxide fuel cell can include nanocrystalline cerium oxide as a cathode component and microcrystalline cerium oxide as an electrolyte component, which can prevent mechanical failure and interdiffusion common in other fuel cells. A solid oxide fuel cell can also include nanocrystalline cerium oxide in the anode. A PEM fuel cell can include cerium oxide as a catalyst support in the cathode and optionally also in the anode.

  19. Preparing oxidizer coated metal fuel particles

    NASA Technical Reports Server (NTRS)

    Shafer, J. I.; Simmons, G. M. (Inventor)

    1974-01-01

    A solid propellant composition of improved efficiency is described which includes an oxidizer containing ammonium perchlorate, and a powered metal fuel, preferably aluminum or beryllium, in the form of a composite. The metal fuel is contained in the crystalline lattice framework of the oxidizer, as well as within the oxidizer particles, and is disposed in the interstices between the oxidizer particles of the composition. The propellant composition is produced by a process comprising the crystallization of ammonium perchlorate in water, in the presence of finely divided aluminum or beryllium. A suitable binder is incorporated in the propellant composition to bind the individual particles of metal with the particles of oxidizer containing occluded metal.

  20. Interfacial material for solid oxide fuel cell

    DOEpatents

    Baozhen, Li; Ruka, Roswell J.; Singhal, Subhash C.

    1999-01-01

    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.

  1. Characteristics of a Mixed Thorium - Uranium Dioxide High-Burnup Fuel

    SciTech Connect

    Herring, James Stephen; Mac Donald, Philip Elsworth

    1999-06-01

    Future nuclear fuel must satisfy three sets of requirements: longer times between refueling; concerns for weapons proliferation; and development of a spent fuel form more suitable for direct geologic disposal. This project has investigated a fuel consisting of mixed thorium and uranium dioxide to satisfy these requirements. Results using the SCALE 4.3 code system indicated that the mixed Th-U fuel could be burned to 72 MWD/kg or 100 MWD/kg using 25% and 35% UO2 respectively. The uranium remained below 20 % total fissile fraction throughout the cycle, making it unusable for weapons. Total plutonium production per MWD was a factor of 4.5 less in the Th-U fuel than in the conventional fuel; Pu-239 production per MWD was a factor of 6.5 less; and the plutonium produced was high in Pu-238, leading to a decay heat 5 times greater than that from plutonium derived from conventional fuel and 40 times greater than weapons grade plutonium. High decay heat would require active cooling of any crude weapon, lest the components surrounding the plutonium be melted. Spontaneous neutron production for plutonium from Th-U fuel was 2.3 times greater than that from conventional fuel and 15 times greater than that from weapons grade plutonium. High spontaneous neutron production drastically limits the probable yield of a crude weapon. Because ThO2 is the highest oxide of thorium, while UO2 can be oxidized further to U3O8, ThO2- UO2 fuel may be a superior wasteform if the spent fuel is ever to be exposed to oxygenated water. Even if the cost of fabricating the mixed Th-U fuel is $100/kg greater, the cost of the Th-U fuel is 13% to 25% less than that of the fuels using uranium only.

  2. Characteristics of a Mixed Thorium-Uranium Dioxide High-Burnup Fuel

    SciTech Connect

    J. S. Herring; P. E. MacDonald

    1999-06-01

    Future nuclear fuels must satisfy three sets of requirements: longer times between refueling; concerns for weapons proliferation; and development of a spent fuel form more suitable for direct geologic disposal. This project has investigated a fuel consisting of mixed thorium and uranium dioxide to satisfy these requirements. Results using the SCALE 4.3 code system indicated that the mixed Th-U fuel could be burned to 72 MWD/kg or 100 MWD/kg using 25% of 35% UO2 respectively. The uranium remained below 20% total fissile fraction throughout the cycle, making it unusable for weapons. Total plutonium production per MWD was a factor of 4.5 less in the Th-U fuel than in the conventional fuel; Pu-239 production per MWD was a factor of 6.5 less; and the plutonium produced was high in Pu-238, leading to a decay heat 5 times greater than that from plutonium derived from conventional fuel and 40 times greater than weapons grade plutonium. High decay heat would require active cooling of any crude weapon, lest the components surrounding the plutonium be melted. Spontaneous neutron production for plutonium from Th-U fuel was 2.3 times greater than that from conventional fuel and 15 times greater than that from weapons grade plutonium. High spontaneous neutron production drastically limits the probable yield of a crude weapon. Because ThO2 is the highest oxide of thorium, while UO2 can be oxidized further to U3O8, ThO2-UO2 fuel may be a superior wasteform if the spent fuel is ever to be exposed to oxygenated water. Even if the cost of fabricating the mixed Th-U fuel is $100/kg greater, the cost of the Th-U fuel is 13% to 15% less than that of the fuels using uranium only.

  3. Solid Oxide Fuel Cell Hybrid System for Distributed Power Generation

    SciTech Connect

    David Deangelis; Rich Depuy; Debashis Dey; Georgia Karvountzi; Nguyen Minh; Max Peter; Faress Rahman; Pavel Sokolov; Deliang Yang

    2004-09-30

    This report summarizes the work performed by Hybrid Power Generation Systems, LLC (HPGS) during the April to October 2004 reporting period in Task 2.3 (SOFC Scaleup for Hybrid and Fuel Cell Systems) 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''. This study analyzes the performance and economics of power generation systems for central power generation application based on Solid Oxide Fuel Cell (SOFC) technology and fueled by natural gas. The main objective of this task is to develop credible scale up strategies for large solid oxide fuel cell-gas turbine systems. System concepts that integrate a SOFC with a gas turbine were developed and analyzed for plant sizes in excess of 20 MW. A 25 MW plant configuration was selected with projected system efficiency of over 65% and a factory cost of under $400/kW. The plant design is modular and can be scaled to both higher and lower plant power ratings. Technology gaps and required engineering development efforts were identified and evaluated.

  4. Solid oxide fuel cell power plant having a fixed contact oxidation catalyzed section of a multi-section cathode air heat exchanger

    DOEpatents

    Saito, Kazuo; Lin, Yao

    2015-02-17

    The multi-section cathode air heat exchanger (102) includes at least a first heat exchanger section (104), and a fixed contact oxidation catalyzed section (126) secured adjacent each other in a stack association. Cool cathode inlet air flows through cool air channels (110) of the at least first (104) and oxidation catalyzed sections (126). Hot anode exhaust flows through hot air channels (124) of the oxidation catalyzed section (126) and is combusted therein. The combusted anode exhaust then flows through hot air channels (112) of the first section (104) of the cathode air heat exchanger (102). The cool and hot air channels (110, 112) are secured in direct heat exchange relationship with each other so that temperatures of the heat exchanger (102) do not exceed 800.degree. C. to minimize requirements for using expensive, high-temperature alloys.

  5. Fuel economizer employing improved turbulent mixing of fuel and air

    SciTech Connect

    Howes, L.D.

    1980-11-25

    A fuel economizer is described for internal combustion engines which increases turbulence of the fuel and air mixture in the carburetor by decreasing the throat of its venturi to a predetermined minimum necessary to induce fuel flow through its fuel jets and then downstream of the venturi adding further atmospheric air for complete combustion.

  6. Electrometallurgical treatment of oxide spent fuel.

    SciTech Connect

    Karell, E. J.

    1999-06-08

    The Department of Energy (DOE) inventory of spent nuclear fuel contains a wide variety of oxide fuel types that may be unsuitable for direct repository disposal in their current form. The molten-salt electrometallurgical treatment technique developed by Argonne National Laboratory (ANL) has the potential to simplify preparing and qualifying these fuels for disposal by converting them into three uniform product streams: uranium metal, a metal waste form, and a ceramic waste form. This paper describes the major steps in the electrometallurgical treatment process for oxide fuels and provides the results of recent experiments performed to develop and scale up the process.

  7. The TMI regenerable solid oxide fuel cell

    NASA Technical Reports Server (NTRS)

    Cable, Thomas L.

    1995-01-01

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

  8. Current status of Westinghouse tubular solid oxide fuel cell program

    SciTech Connect

    Parker, W.G.

    1996-04-01

    In the last ten years the solid oxide fuel cell (SOFC) development program at Westinghouse has evolved from a focus on basic material science to the engineering of fully integrated electric power systems. Our endurance for this cell is 5 to 10 years. To date we have successfully operated at power for over six years. For power plants it is our goal to have operated before the end of this decade a MW class power plant. Progress toward these goals is described.

  9. Advances in code validation for mixed-oxide fuel use in light-water reactors through benchmark experiments in the VENUS critical facility

    SciTech Connect

    D'hondt, Pierre; Baeten, Peter; Lance, Bernard; Marloye, Daniel; Basselier, Jacques

    2004-07-01

    Based on the experience accumulated during 25-years of collaboration SCK.CEN together with Belgonucleaire decided to implement a series of Benchmark experiments in the VENUS critical facility in Mol, Belgium in order to give to organizations concerned with MOX fuel the possibility to calibrate and to improve their neutronic calculation tools. In this paper these Benchmark programmes and their outcome are highlighted, they have demonstrated that VENUS is a very flexible and easy to use tool for the investigation of neutronic data as well as for the study of licensing, safety and operation aspects for MOX use in LWR's. (authors)

  10. Alternative oxidation technologies for organic mixed waste

    SciTech Connect

    Borduin, L.C.; Fewell, T.

    1998-07-01

    The Mixed Waste Focus Area (MWFA) is currently supporting the development and demonstration of several alternative oxidation technology (AOT) processes for treatment of combustible mixed low-level wastes. AOTs have been defined as technologies that destroy organic material without using open-flame reactions. AOTs include both thermal and nonthermal processes that oxidize organic wastes but operate under significantly different physical and chemical conditions than incinerators. Nonthermal processes currently being studied include Delphi DETOX and acid digestion at the Savannah River Site (SRS), and direct chemical oxidation at Lawrence Livermore National Laboratory (LLNL). All three technologies are at advanced stages of development or are entering the demonstration phase. Nonflame thermal processes include catalytic chemical oxidation, which is being developed and deployed at Lawrence Berkeley National Laboratory (LBNL), and steam reforming, a commercial process being supported by the Department of Energy (DOE). Although testing is complete on some AOT technologies, most require additional support to complete some or all of the identified development objectives. Brief descriptions, status, and planned paths forward for each of the technologies are presented.

  11. Interconnection of bundled solid oxide fuel cells

    DOEpatents

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

    2014-01-14

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

  12. Pyrochemical processes for the recovery of weapons grade plutonium either as a metal or as PuO{sub 2} for use in mixed oxide reactor fuel pellets

    SciTech Connect

    Colmenares, C.A.; Ebbinghaus, B.B.; Bronson, M.C.

    1995-11-03

    The authors have developed two processes for the recovery of weapons grade Pu, as either Pu metal or PuO{sub 2}, that are strictly pyrochemical and do not produce any liquid waste. Large amounts of Pu metal (up to 4 kg.), in various geometric shapes, have been recovered by a hydride/dehydride/casting process (HYDEC) to produce metal ingots of any desired shape. The three processing steps are carried out in a single compact apparatus. The experimental technique and results obtained will be described. The authors have prepared PuO{sub 2} powders from weapons grade Pu by a process that hydrides the Pu metal followed by the oxidation of the hydride (HYDOX process). Experimental details of the best way to carry out this process will be presented, as well as the characterization of both hydride and oxide powders produced.

  13. 40 CFR 721.5548 - Mixed metal oxide (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Mixed metal oxide (generic). 721.5548... Substances § 721.5548 Mixed metal oxide (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as a mixed metal oxide (PMN P-97-956)...

  14. 40 CFR 721.4610 - Mixed metal oxides (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Mixed metal oxides (generic). 721.4610... Substances § 721.4610 Mixed metal oxides (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as mixed metal oxides (PMN...

  15. 40 CFR 721.4610 - Mixed metal oxides (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Mixed metal oxides (generic). 721.4610... Substances § 721.4610 Mixed metal oxides (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as mixed metal oxides (PMN...

  16. 40 CFR 721.4610 - Mixed metal oxides (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Mixed metal oxides (generic). 721.4610... Substances § 721.4610 Mixed metal oxides (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as mixed metal oxides (PMN...

  17. 40 CFR 721.10006 - Mixed metal oxide (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Mixed metal oxide (generic). 721.10006... Substances § 721.10006 Mixed metal oxide (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as mixed metal oxide (PMN...

  18. 40 CFR 721.4610 - Mixed metal oxides (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Mixed metal oxides (generic). 721.4610... Substances § 721.4610 Mixed metal oxides (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as mixed metal oxides (PMN...

  19. 40 CFR 721.5548 - Mixed metal oxide (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Mixed metal oxide (generic). 721.5548... Substances § 721.5548 Mixed metal oxide (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as a mixed metal oxide (PMN P-97-956)...

  20. 40 CFR 721.10006 - Mixed metal oxide (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Mixed metal oxide (generic). 721.10006... Substances § 721.10006 Mixed metal oxide (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as mixed metal oxide (PMN...

  1. 40 CFR 721.5548 - Mixed metal oxide (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Mixed metal oxide (generic). 721.5548... Substances § 721.5548 Mixed metal oxide (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as a mixed metal oxide (PMN P-97-956)...

  2. 40 CFR 721.4610 - Mixed metal oxides (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Mixed metal oxides (generic). 721.4610... Substances § 721.4610 Mixed metal oxides (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as mixed metal oxides (PMN...

  3. 40 CFR 721.10006 - Mixed metal oxide (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Mixed metal oxide (generic). 721.10006... Substances § 721.10006 Mixed metal oxide (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as mixed metal oxide (PMN...

  4. 40 CFR 721.10500 - Acrylated mixed metal oxides (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Acrylated mixed metal oxides (generic... Specific Chemical Substances § 721.10500 Acrylated mixed metal oxides (generic). (a) Chemical substance and... mixed metal oxides (PMN P-06-341) is subject to reporting under this section for the significant...

  5. 40 CFR 721.5548 - Mixed metal oxide (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Mixed metal oxide (generic). 721.5548... Substances § 721.5548 Mixed metal oxide (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as a mixed metal oxide (PMN P-97-956)...

  6. 40 CFR 721.5548 - Mixed metal oxide (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Mixed metal oxide (generic). 721.5548... Substances § 721.5548 Mixed metal oxide (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as a mixed metal oxide (PMN P-97-956)...

  7. 40 CFR 721.10500 - Acrylated mixed metal oxides (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Acrylated mixed metal oxides (generic... Specific Chemical Substances § 721.10500 Acrylated mixed metal oxides (generic). (a) Chemical substance and... mixed metal oxides (PMN P-06-341) is subject to reporting under this section for the significant...

  8. 40 CFR 721.10006 - Mixed metal oxide (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Mixed metal oxide (generic). 721.10006... Substances § 721.10006 Mixed metal oxide (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as mixed metal oxide (PMN...

  9. 40 CFR 721.10006 - Mixed metal oxide (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Mixed metal oxide (generic). 721.10006... Substances § 721.10006 Mixed metal oxide (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as mixed metal oxide (PMN...

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

    DOEpatents

    Singh, P.; George, R.A.

    1999-07-27

    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.

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

    DOEpatents

    Singh, Prabhakar; George, Raymond A.

    1999-01-01

    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.

  12. Late-occurring pulmonary pathologies following inhalation of mixed oxide (uranium + plutonium oxide) aerosol in the rat.

    PubMed

    Griffiths, N M; Van der Meeren, A; Fritsch, P; Abram, M-C; Bernaudin, J-F; Poncy, J L

    2010-09-01

    Accidental exposure by inhalation to alpha-emitting particles from mixed oxide (MOX: uranium and plutonium oxide) fuels is a potential long-term health risk to workers in nuclear fuel fabrication plants. For MOX fuels, the risk of lung cancer development may be different from that assigned to individual components (plutonium, uranium) given different physico-chemical characteristics. The objective of this study was to investigate late effects in rat lungs following inhalation of MOX aerosols of similar particle size containing 2.5 or 7.1% plutonium. Conscious rats were exposed to MOX aerosols and kept for their entire lifespan. Different initial lung burdens (ILBs) were obtained using different amounts of MOX. Lung total alpha activity was determined by external counting and at autopsy for total lung dose calculation. Fixed lung tissue was used for anatomopathological, autoradiographical, and immunohistochemical analyses. Inhalation of MOX at ILBs ranging from 1-20 kBq resulted in lung pathologies (90% of rats) including fibrosis (70%) and malignant lung tumors (45%). High ILBs (4-20 kBq) resulted in reduced survival time (N = 102; p < 0.05) frequently associated with lung fibrosis. Malignant tumor incidence increased linearly with dose (up to 60 Gy) with a risk of 1-1.6% Gy for MOX, similar to results for industrial plutonium oxide alone (1.9% Gy). Staining with antibodies against Surfactant Protein-C, Thyroid Transcription Factor-1, or Oct-4 showed differential labeling of tumor types. In conclusion, late effects following MOX inhalation result in similar risk for development of lung tumors as compared with industrial plutonium oxide.

  13. Sintered electrode for solid oxide fuel cells

    DOEpatents

    Ruka, Roswell J.; Warner, Kathryn A.

    1999-01-01

    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.

  14. Multi scale and physics models for intermediate and low temperatures H+-solid oxide fuel cells with H+/e-/O2- mixed conducting properties: Part A, generalized percolation theory for LSCF-SDC-BZCY 3-component cathodes

    NASA Astrophysics Data System (ADS)

    Chen, Daifen; Zhang, Qiang; Lu, Liu; Periasamy, Vijay; Tade, Moses O.; Shao, Zongping

    2016-01-01

    H+ based solid oxide fuel cell (SOFC) composite cathodes are generally agreed to be of quite different relationships among the microstructure parameters, electrode properties and detailed working processes from the conventional O2--SOFC composite cathodes. In this paper, the percolation theory is significantly generalized and developed to suit most of the typical H+-SOFC composite cathodes with e-/H+, e-/O2- or e-/H+/O2- mixed conducting characteristics; not just limited to the BCZY, SDC and LSCF materials. It provides an easy way to investigate the effect of microstructure parameters on the H+-SOFC electrode characteristics in quantity. The studied electrode properties include: i) the potential coexisting sites of O2, e-, and O2- transport paths for the oxygen reduction; ii) the potential coexisting sites of O2-, H+ and H2O transport paths for the vapor formation; iii) the effective e-, O2-, and H+ conducting and gas diffusing capabilities of the composite cathodes, and so on. It will be helpful for the H+-SOFC composite cathode manufacture to achieve the expected properties. Furthermore, it is also an important step for the developing of the multiphysics-model in manuscript part B to study the effect of the microstructure parameters on the H+-SOFC working details.

  15. A mixed-conducting BaPr0.8In0.2O3-δ cathode for proton-conducting solid oxide fuel cells

    SciTech Connect

    Zhihong, Wang; Liu, Mingfei; Sun, Wenping; Ding, Dong; Lu, Zhe; Liu, Meilin

    2012-11-02

    A mixed ionic and electronic conductor, BaPr0.8In0.2O3-δ (BPI), was synthesized and examined as a cathode material for proton-conducting solid oxide fuel cells (H-SOFCs). X-ray diffraction analysis revealed that BPI had a perovskite structure and showed satisfactory tolerance to CO2 and H2O and good chemical compatibility with BaZr0.1Ce0.7Y0.1Yb0.1O3-δ (BZCYYb) electrolyte. Test cells with a single-phase BPI cathode exhibited excellent electrochemical performances, demonstrating a peak power density of ~ 688 mW cm- 2 at 750 °C. Furthermore, the cells with a BPI cathode showed very stable power output at a cell voltage of 0.7 V at 600 °C over 100 h, suggesting that BPI is a promising alternative cathode for H-SOFCs.

  16. FY 1992 Annual report: Mediated electrochemical oxidation treatment for Rocky Flats combustible low-level mixed waste. Final report to Rocky Flats Plant

    SciTech Connect

    Chiba, Z.; Lewis, P.R.; Kahle, R.W.

    1993-03-01

    The Mediated Electrochemical Oxidation (MEO) process was studied for destroying low-level combustible mixed wastes at Rocky Flats (RFP). Tests were performed with nonradioactive surrogate materials: Trimsol for the contaminated oils, and reagent-grade cellulose for the cellulosic wastes. Extensive testing was carried out on Trimsol in both small laboratory-scale apparatus and on a large-scale system incorporating an industrial-size electrochemical cell. Preliminary tests were also carried out in the small-scale system with cellulose. The following operating and system parameters were studied: use of a silver-nitric acid versus a cobalt-sulfuric acid system, effect of electrolyte temperature, effect of acid concentration, effect of current density, and use of ultrasonic agitation. Destruction and coulombic efficiencies were calculated using data obtained from continuous carbon dioxide monitors and total organic carbon (TOC) analysis of electrolyte samples. For Trimsol, the best performance was achieved with the silver-nitrate system at high acid concentrations, temperatures, and current densities. Destruction efficiencies of 98% or greater and coulombic efficiencies close to 50% were obtained in both small- and large-scale systems. For the cellulose, high destruction efficiencies and reasonable coulombic efficiencies were obtained for both silver-nitrate and cobalt-sulfate systems.

  17. Hydrothermal Oxidation Hazardous Waste Pilot Plant Test Bed

    SciTech Connect

    Welland, H.; Reed, W.; Valentich, D.; Charlton, T.

    1995-03-01

    The Idaho National Engineering Laboratory (INEL) is fabricating a Hydrothermal Oxidation (HTO) Hazardous Waste Pilot Plant Test Bed to evaluate and test various HTO reactor concepts for initial processing of the U.S. Department of Energy (DOE) mixed wastes. If the HTO process is successful it will significantly reduce the volume of DOE mixed wastes by destroying the organic constituents.

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

    SciTech Connect

    Mark Perna; Anant Upadhyayula; Mark Scotto

    2012-11-05

    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.

  19. System for operating solid oxide fuel cell generator on diesel fuel

    NASA Technical Reports Server (NTRS)

    Singh, Prabhu (Inventor); George, Raymond A. (Inventor)

    1997-01-01

    A system is provided for operating a solid oxide fuel cell generator on diesel fuel. The system includes a hydrodesulfurizer which reduces the sulfur content of commercial and military grade diesel fuel to an acceptable level. Hydrogen which has been previously separated from the process stream is mixed with diesel fuel at low pressure. The diesel/hydrogen mixture is then pressurized and introduced into the hydrodesulfurizer. The hydrodesulfurizer comprises a metal oxide such as ZnO which reacts with hydrogen sulfide in the presence of a metal catalyst to form a metal sulfide and water. After desulfurization, the diesel fuel is reformed and delivered to a hydrogen separator which removes most of the hydrogen from the reformed fuel prior to introduction into a solid oxide fuel cell generator. The separated hydrogen is then selectively delivered to the diesel/hydrogen mixer or to a hydrogen storage unit. The hydrogen storage unit preferably comprises a metal hydride which stores hydrogen in solid form at low pressure. Hydrogen may be discharged from the metal hydride to the diesel/hydrogen mixture at low pressure upon demand, particularly during start-up and shut-down of the system.

  20. Solid Oxide Fuel Cells Operating on Alternative and Renewable Fuels

    SciTech Connect

    Wang, Xiaoxing; Quan, Wenying; Xiao, Jing; Peduzzi, Emanuela; Fujii, Mamoru; Sun, Funxia; Shalaby, Cigdem; Li, Yan; Xie, Chao; Ma, Xiaoliang; Johnson, David; Lee, Jeong; Fedkin, Mark; LaBarbera, Mark; Das, Debanjan; Thompson, David; Lvov, Serguei; Song, Chunshan

    2014-09-30

    This DOE project at the Pennsylvania State University (Penn State) initially involved Siemens Energy, Inc. to (1) develop new fuel processing approaches for using selected alternative and renewable fuels – anaerobic digester gas (ADG) and commercial diesel fuel (with 15 ppm sulfur) – in solid oxide fuel cell (SOFC) power generation systems; and (2) conduct integrated fuel processor – SOFC system tests to evaluate the performance of the fuel processors and overall systems. Siemens Energy Inc. was to provide SOFC system to Penn State for testing. The Siemens work was carried out at Siemens Energy Inc. in Pittsburgh, PA. The unexpected restructuring in Siemens organization, however, led to the elimination of the Siemens Stationary Fuel Cell Division within the company. Unfortunately, this led to the Siemens subcontract with Penn State ending on September 23rd, 2010. SOFC system was never delivered to Penn State. With the assistance of NETL project manager, the Penn State team has since developed a collaborative research with Delphi as the new subcontractor and this work involved the testing of a stack of planar solid oxide fuel cells from Delphi.

  1. Intermediate Temperature Solid Oxide Fuel Cell Development

    SciTech Connect

    S. Elangovan; Scott Barnett; Sossina Haile

    2008-06-30

    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

  2. Fuel cell power plant integrated systems evaluation

    NASA Astrophysics Data System (ADS)

    Bonds, T. L.; Dawes, M. H.; Schnacke, A. W.; Spradlin, L. W.

    1981-01-01

    Power plant configurations for a central station (675 MW) fueled by coal and small dispersed plan generation plants fueled by oil were defined. Capital costs and costs for electricity were evaluated for both plants. Parametric variations and the impact on plants and components are discussed. Alternate oil fueled oil fired cycles as well as several alternate coal gasifiers were examined to show effects on plant performance. The economic attractiveness of the coal fired plant was confirmed and a scenario is established for an oil fired plant with reject heat recovery. Performance for the coal fired plant exceeds the study goal of 6800 Btu/kWh. The oil fired plant performance of 7627 Btu/kWh is very close to the study goal of 7500 Btu/kWh. The development of a finite slice computer model of the carbonate fuel cell is reported and an initial parametric cell and plant performance study was performed using the model. Preliminary subsystem description sheets and plant layout arrangements are presented.

  3. Investigation of Mixed Oxide Catalysts for NO Oxidation

    SciTech Connect

    Szanyi, Janos; Karim, Ayman M.; Pederson, Larry R.; Kwak, Ja Hun; Mei, Donghai; Tran, Diana N.; Herling, Darrell R.; Muntean, George G.; Peden, Charles HF; Howden, Ken; Qi, Gongshin; Li, Wei

    2014-12-09

    The oxidation of engine-generated NO to NO2 is an important step in the reduction of NOx in lean engine exhaust because NO2 is required for the performance of the LNT technology [2], and it enhances the activities of ammonia selective catalytic reduction (SCR) catalysts [1]. In particular, for SCR catalysts an NO:NO2 ratio of 1:1 is most effective for NOx reduction, whereas for LNT catalysts, NO must be oxidized to NO2 before adsorption on the storage components. However, NO2 typically constitutes less than 10% of NOx in lean exhaust, so catalytic oxidation of NO is essential. Platinum has been found to be especially active for NO oxidation, and is widely used in DOC and LNT catalysts. However, because of the high cost and poor thermal durability of Pt-based catalysts, there is substantial interest in the development of alternatives. The objective of this project, in collaboration with partner General Motors, is to develop mixed metal oxide catalysts for NO oxidation, enabling lower precious metal usage in emission control systems. [1] M. Koebel, G. Madia, and M. Elsener, Catalysis Today 73, 239 (2002). [2] C. H. Kim, G. S. Qi, K. Dahlberg, and W. Li, Science 327, 1624 (2010).

  4. An Innovative Injection and Mixing System for Diesel Fuel Reforming

    SciTech Connect

    Spencer Pack

    2007-12-31

    This project focused on fuel stream preparation improvements prior to injection into a solid oxide fuel cell reformer. Each milestone and the results from each milestone are discussed in detail in this report. The first two milestones were the creation of a coking formation test rig and various testing performed on this rig. Initial tests indicated that three anti-carbon coatings showed improvement over an uncoated (bare metal) baseline. However, in follow-up 70 hour tests of the down selected coatings, Scanning Electron Microscope (SEM) analysis revealed that no carbon was generated on the test specimens. These follow-up tests were intended to enable a down selection to a single best anti-carbon coating. Without the formation of carbon it was impossible to draw conclusions as to which anti-carbon coating showed the best performance. The final 70 hour tests did show that AMCX AMC26 demonstrated the lowest discoloration of the metal out of the three down selected anti-carbon coatings. This discoloration did not relate to carbon but could be a useful result when carbon growth rate is not the only concern. Unplanned variations in the series of tests must be considered and may have altered the results. Reliable conclusions could only be drawn from consistent, repeatable testing beyond the allotted time and funding for this project. Milestones 3 and 4 focused on the creation of a preheating pressure atomizer and mixing chamber. A design of experiment test helped identify a configuration of the preheating injector, Build 1, which showed a very uniform fuel spray flow field. This injector was improved upon by the creation of a Build 2 injector. Build 2 of the preheating injector demonstrated promising SMD results with only 22psi fuel pressure and 0.7 in H2O of Air. It was apparent from testing and CFD that this Build 2 has flow field recirculation zones. These recirculation zones may suggest that this Build 2 atomizer and mixer would require steam injection to reduce the

  5. Solid oxide MEMS-based fuel cells

    DOEpatents

    Jankowksi, Alan F.; Morse, Jeffrey D.

    2007-03-13

    A micro-electro-mechanical systems (MEMS) based thin-film fuel cells for electrical power applications. The MEMS-based fuel cell may be of a solid oxide type (SOFC), a solid polymer type (SPFC), or a proton exchange membrane type (PEMFC), and each fuel cell basically consists of an anode and a cathode separated by an electrolyte layer. The electrolyte layer can consist of either a solid oxide or solid polymer material, or proton exchange membrane electrolyte materials may be used. Additionally catalyst layers can also separate the electrodes (cathode and anode) from the electrolyte. Gas manifolds are utilized to transport the fuel and oxidant to each cell and provide a path for exhaust gases. The electrical current generated from each cell is drawn away with an interconnect and support structure integrated with the gas manifold. The fuel cells utilize integrated resistive heaters for efficient heating of the materials. By combining MEMS technology with thin-film deposition technology, thin-film fuel cells having microflow channels and full-integrated circuitry can be produced that will lower the operating temperature an will yield an order of magnitude greater power density than the currently known fuel cells.

  6. Fuel cell power supply with oxidant and fuel gas switching

    DOEpatents

    McElroy, James F.; Chludzinski, Paul J.; Dantowitz, Philip

    1987-01-01

    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.

  7. Fuel cell power supply with oxidant and fuel gas switching

    DOEpatents

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

    1987-04-14

    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.

  8. Direct oxidation of jet fuels and Pennsylvania crude oil in a solid oxide fuel cell

    NASA Astrophysics Data System (ADS)

    Zhou, Z. F.; Gallo, C.; Pague, M. B.; Schobert, H.; Lvov, S. N.

    A Cu-ceria solid oxide fuel cell (SOFC) is shown to generate electric power using jet fuels and Pennsylvania crude oil through direct oxidation of the fuels. The liquid fuels contained up to 910 ppm of sulfur and were injected into the anode compartment either with or without N 2 dilution. The performance of the fuel cell was stable over 30 h for jet fuels and Pennsylvania crude oil without N 2 dilution whereas N 2 dilution prolonged the stable power generation up to 100 h for jet fuel and up to 80 h for Pennsylvania crude oil. The generated power density was about 0.1 W cm -2 for both fuels.

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

    SciTech Connect

    Daniel Birmingham; Crispin Debellis; Mark Perna; Anant Upadhyayula

    2008-02-28

    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

  10. ZPR-6 assembly 7 high {sup 240}Pu core experiments : a fast reactor core with mixed (Pu,U)-oxide fuel and a centeral high{sup 240}Pu zone.

    SciTech Connect

    Lell, R. M.; Morman, J. A.; Schaefer, R.W.; McKnight, R.D.; Nuclear Engineering Division

    2009-02-23

    ZPR-6 Assembly 7 (ZPR-6/7) encompasses a series of experiments performed at the ZPR-6 facility at Argonne National Laboratory in 1970 and 1971 as part of the Demonstration Reactor Benchmark Program (Reference 1). Assembly 7 simulated a large sodium-cooled LMFBR with mixed oxide fuel, depleted uranium radial and axial blankets, and a core H/D near unity. ZPR-6/7 was designed to test fast reactor physics data and methods, so configurations in the Assembly 7 program were as simple as possible in terms of geometry and composition. ZPR-6/7 had a very uniform core assembled from small plates of depleted uranium, sodium, iron oxide, U{sub 3}O{sub 8} and Pu-U-Mo alloy loaded into stainless steel drawers. The steel drawers were placed in square stainless steel tubes in the two halves of a split table machine. ZPR-6/7 had a simple, symmetric core unit cell whose neutronic characteristics were dominated by plutonium and {sup 238}U. The core was surrounded by thick radial and axial regions of depleted uranium to simulate radial and axial blankets and to isolate the core from the surrounding room. The ZPR-6/7 program encompassed 139 separate core loadings which include the initial approach to critical and all subsequent core loading changes required to perform specific experiments and measurements. In this context a loading refers to a particular configuration of fueled drawers, radial blanket drawers and experimental equipment (if present) in the matrix of steel tubes. Two principal core configurations were established. The uniform core (Loadings 1-84) had a relatively uniform core composition. The high {sup 240}Pu core (Loadings 85-139) was a variant on the uniform core. The plutonium in the Pu-U-Mo fuel plates in the uniform core contains 11% {sup 240}Pu. In the high {sup 240}Pu core, all Pu-U-Mo plates in the inner core region (central 61 matrix locations per half of the split table machine) were replaced by Pu-U-Mo plates containing 27% {sup 240}Pu in the plutonium

  11. DIRECT FUEL CELL/TURBINE POWER PLANT

    SciTech Connect

    Hossein Ghezel-Ayagh

    2004-11-01

    This report includes the progress in development of Direct FuelCell/Turbine{reg_sign} (DFC/T{reg_sign}) power plants for generation of clean power at very high efficiencies. The DFC/T power system is based on an indirectly heated gas turbine to supplement fuel cell generated power. The DFC/T power generation concept extends the high efficiency of the fuel cell by utilizing the fuel cell's byproduct heat in a Brayton cycle. Features of the DFC/T system include: electrical efficiencies of up to 75% on natural gas, 60% on coal gas, minimal emissions, simplicity in design, direct reforming internal to the fuel cell, reduced carbon dioxide release to the environment, and potential cost competitiveness with existing combined cycle power plants. The operation of sub-MW hybrid Direct FuelCell/Turbine power plant test facility with a Capstone C60 microturbine was initiated in March 2003. The inclusion of the C60 microturbine extended the range of operation of the hybrid power plant to higher current densities (higher power) than achieved in previous tests using a 30kW microturbine. The design of multi-MW DFC/T hybrid systems, approaching 75% efficiency on natural gas, was initiated. A new concept was developed based on clusters of One-MW fuel cell modules as the building blocks. System analyses were performed, including systems for near-term deployment and power plants with long-term ultra high efficiency objectives. Preliminary assessment of the fuel cell cluster concept, including power plant layout for a 14MW power plant, was performed.

  12. Synergetic effects of mixed copper-iron oxides oxygen carriers in chemical looping combustion

    SciTech Connect

    Siriwardane, Ranjani; Tian, Hanjing; Simonyi, Thomas; Poston, James

    2013-06-01

    Chemical looping combustion (CLC) is an emerging technology for clean energy production from fuels. CLC produces sequestration-ready CO{sub 2}-streams without a significant energy penalty. Development of efficient oxygen carriers is essential to successfully operate a CLC system. Copper and iron oxides are promising candidates for CLC. Copper oxide possesses high reactivity but it has issues with particle agglomeration due to its low melting point. Even though iron oxide is an inexpensive oxygen carrier it has a slower reactivity. In this study, mixed metal oxide carriers containing iron and copper oxides were evaluated for coal and methane CLC. The components of CuO and Fe{sub 2}O{sub 3} were optimized to obtain good reactivity while maintaining physical and chemical stability during cyclic reactions for methane-CLC and solid-fuel CLC. Compared with single metal oxygen carriers, the optimized Cu–Fe mixed oxide oxygen carriers demonstrated high reaction rate, better combustion conversion, greater oxygen usage and improved physical stability. Thermodynamic calculations, XRD, TGA, flow reactor studies and TPR experiments suggested that there is a strong interaction between CuO and Fe{sub 2}O{sub 3} contributing to a synergistic effect during CLC reactions. The amount of oxygen release of the mixed oxide carrier in the absence of a fuel was similar to that of the single metal oxides. However, in the presence of fuels, the oxygen consumption and the reaction profiles of the mixed oxide carriers were significantly better than that of the single metal oxides. The nature of the fuel not only influenced the reactivity, but also the final reduction status of the oxygen carriers during chemical looping combustion. Cu oxide of the mixed oxide was fully reduced metallic copper with both coal and methane. Fe oxide of the mixed oxide was fully reduced Fe metal with methane but it was reduced to only FeO with coal. Possible mechanisms of how the presence of CuO enhances the

  13. Monolithic solid oxide fuel cell development

    NASA Technical Reports Server (NTRS)

    Myles, K. M.; Mcpheeters, C. C.

    1989-01-01

    The feasibility of the monolithic solid oxide fuel cell (MSOFC) concept has been proven, and the performance has been dramatically improved. The differences in thermal expansion coefficients and firing shrinkages among the fuel cell materials have been minimized, thus allowing successful fabrication of the MSOFC with few defects. The MSOFC shows excellent promise for development into a practical power source for many applications from stationary power, to automobile propulsion, to space pulsed power.

  14. Miniature Oxidizer Ionizer for a Fuel Cell

    NASA Technical Reports Server (NTRS)

    Hartley, Frank

    2006-01-01

    A proposed miniature device for ionizing the oxygen (or other oxidizing gas) in a fuel cell would consist mostly of a membrane ionizer using the same principles as those of the device described in the earlier article, Miniature Bipolar Electrostatic Ion Thruster (NPO-21057). The oxidizing gas would be completely ionized upon passage through the holes in the membrane ionizer. The resulting positively charged atoms or molecules of oxidizing gas could then, under the influence of the fringe fields of the ionizer, move toward the fuel-cell cathode that would be part of a membrane/electrode assembly comprising the cathode, a solid-electrolyte membrane, and an anode. The electro-oxidized state of the oxidizer atoms and molecules would enhance transfer of them through the cathode, thereby reducing the partial pressure of the oxidizer gas between the ionizer and the fuel-cell cathode, thereby, in turn, causing further inflow of oxidizer gas through the holes in the membrane ionizer. Optionally the ionizer could be maintained at a positive electric potential with respect to the cathode, in which case the resulting electric field would accelerate the ions toward the cathode.

  15. The TMI Regenerative Solid Oxide Fuel Cell

    NASA Technical Reports Server (NTRS)

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

    1996-01-01

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

  16. FLUORINATION OF OXIDIC NUCLEAR FUEL

    DOEpatents

    Mecham, W.J.; Gabor, J.D.

    1963-07-23

    A process of volatilizing fissionable material away from fission products, present together in neutron-bombarded uranium oxide, by reaction with an oxygen-fluorine mixture at 350 to 500 deg C is described. (AEC)

  17. Tubular solid oxide fuel cell demonstration activities

    SciTech Connect

    Ray, E.R.; Veyo, S.E.

    1995-12-31

    This reports on a solid oxide fuel cell demonstration program in which utilities are provided fully integrated, automatically controlled, packaged solid oxide fuel cell power generation systems. These field units serve to demonstrate to customers first hand the beneficial attributes of the SOFC, to expose deficiencies through experience in order to guide continued development, and to garner real world feedback and data concerning not only cell and stack parameters, but also transportation, installation, permitting and licensing, start-up and shutdown, system alarming, fault detection, fault response, and operator interaction.

  18. Fuel oxidation efficiencies and exhaust composition in solid oxide fuel cells.

    PubMed

    Pomfret, Michael B; Demircan, Oktay; Sukeshini, A Mary; Walker, Robert A

    2006-09-01

    Solid oxide fuel cells (SOFCs) are electrochemical devices that rely on ion migration through a solid-state electrolyte to oxidize fuel and produce electricity. The present study employs Fourier transform infrared spectroscopy to quantify the exhaust of an SOFC operating with fuel flows of methane over Ni/YSZ cermet anodes and butane over Ni/YSZ and Cu/CeO2/YSZ cermet anodes. Data show that hydrocarbon fuels can participate in a variety of different reactions including direct electrochemical oxidation, various reforming processes, and surface-catalyzed carbon deposition. These findings have direct consequences for assessing the environmental impact of SOFCs in terms of the exhaust discharged from devices operating with common hydrocarbon fuel feeds. In the work presented below, a measure of fuel oxidation efficiency is found by comparing the partial pressure of CO2 (P(CO2)) in the SOFC exhaust to the partial pressure of CO (P(CO)). The fuel anode combination with the largest P(CO2)/P(CO) ratio is the C4H10 over Cu/CeO2 combination (0.628 +/- 0.016). The CH4 over Ni cell type has the second highest ratio (0.486 +/- 0.023). The C4H10 over Ni cell type gives a ratio of 0.224 +/- 0.001. Attempts to balance the carbon content of the fuel feed and exhaust lead to predictions of SOFC fuel oxidation mechanisms.

  19. Implementation of deep soil mixing at the Kansas City Plant

    SciTech Connect

    Gardner, F.G.; Korte, N.; Strong-Gunderson, J.; Siegrist, R.L.; West, O.R.; Cline, S.R.; Baker, J.

    1998-11-01

    In July 1996, the US Department of Energy (DOE) Kansas City Plant (KCP), AlliedSignal Federal Manufacturing and Technologies, and Oak Ridge National Laboratory (ORNL), conducted field-scale tests of in situ soil mixing and treatment technologies within the Northeast Area (NEA) of the KCP at the Former Ponds site. This demonstration, testing, and evaluation effort was conducted as part of the implementation of a deep soil mixing (DSM) innovative remedial technology demonstration project designed to test DSM in the low-permeability clay soils at the KCP. The clay soils and groundwater beneath this area are contaminated by volatile organic compounds (VOCs), primarily trichloroethene (TCE) and 1,2-dichloroethene (1,2-DCE). The demonstration project was originally designed to evaluate TCE and 1,2-DCE removal efficiency using soil mixing coupled with vapor stripping. Treatability study results, however, indicated that mixed region vapor stripping (MRVS) coupled with calcium oxide (dry lime powder) injection would improve TCE and 1,2-DCE removal efficiency in saturated soils. The scope of the KCP DSM demonstration evolved to implement DSM with the following in situ treatment methodologies for contaminant source reduction in soil and groundwater: DSM/MRVS coupled with calcium oxide injection; DSM/bioaugmentation; and DSM/chemical oxidation using potassium permanganate. Laboratory treatability studies were started in 1995 following collection of undisturbed soil cores from the KCP. These studies were conducted at ORNL, and the results provided information on optimum reagent concentrations and mixing ratios for the three in situ treatment agents to be implemented in the field demonstration.

  20. Tubular solid oxide fuel cell current collector

    DOEpatents

    Bischoff, Brian L.; Sutton, Theodore G.; Armstrong, Timothy R.

    2010-07-20

    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.

  1. Mathematical modeling of solid oxide fuel cells

    NASA Technical Reports Server (NTRS)

    Lu, Cheng-Yi; Maloney, Thomas M.

    1988-01-01

    Development of predictive techniques, with regard to cell behavior, under various operating conditions is needed to improve cell performance, increase energy density, reduce manufacturing cost, and to broaden utilization of various fuels. Such technology would be especially beneficial for the solid oxide fuel cells (SOFC) at it early demonstration stage. The development of computer models to calculate the temperature, CD, reactant distributions in the tubular and monolithic SOFCs. Results indicate that problems of nonuniform heat generation and fuel gas depletion in the tubular cell module, and of size limitions in the monolithic (MOD 0) design may be encountered during FC operation.

  2. Sealant materials for solid oxide fuel cells

    SciTech Connect

    Krumpelt, M.

    1995-08-01

    The objective of this work is to complete the development of soft glass-ceramic sealants for the solid oxide fuel cell (SOFC). Among other requirements, the materials must soften at the operation temperature of the fuel cell (600-1000{degrees}C) to relieve stresses between stack components, and their thermal expansions must be tailored to match those of the stack materials. Specific objectives included addressing the needs of industrial fuel cell developers, based on their evaluation of samples we supply, as well as working with commercial glass producers to achieve scaled-up production of the materials without changing their properties.

  3. Solid oxide fuel cell process and apparatus

    DOEpatents

    Cooper, Matthew Ellis; Bayless, David J.; Trembly, Jason P.

    2011-11-15

    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.

  4. Stability of solid oxide fuel cell materials

    SciTech Connect

    Armstrong, T.R.; Bates, J.L.; Chick, L.A.

    1996-04-01

    Interconnection materials in a solid oxide fuel cell are exposed to both highly oxidizing conditions at the cathode and to highly reducing conditions at the anode. The thermal expansion characteristics of substituted lanthanum and yttrium chromite interconnect materials were evaluated by dilatometry as a function of oxygen partial pressures from 1 atm to 10{sup -18} atm, controlled using a carbon dioxide/hydrogen buffer.

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

    NASA Astrophysics Data System (ADS)

    Scherrer, Barbara; Evans, Anna; Santis-Alvarez, Alejandro J.; Jiang, Bo; Martynczuk, Julia; Galinski, Henning; Nabavi, Majid; Prestat, Michel; Tölke, René; Bieberle-Hütter, Anja; Poulikakos, Dimos; Muralt, Paul; Niedermann, Philippe; Dommann, Alex; Maeder, Thomas; Heeb, Peter; Straessle, Valentin; Muller, Claude; Gauckler, Ludwig J.

    2014-07-01

    Low temperature micro-solid oxide fuel cell (micro-SOFC) systems are an attractive alternative power source for small-size portable electronic devices due to their high energy efficiency and density. Here, we report on a thermally self-sustainable reformer-micro-SOFC assembly. The device consists of a micro-reformer bonded to a silicon chip containing 30 micro-SOFC membranes and a functional glass carrier with gas channels and screen-printed heaters for start-up. Thermal independence of the device from the externally powered heater is achieved by exothermic reforming reactions above 470 °C. The reforming reaction and the fuel gas flow rate of the n-butane/air gas mixture controls the operation temperature and gas composition on the micro-SOFC membrane. In the temperature range between 505 °C and 570 °C, the gas composition after the micro-reformer consists of 12 vol.% to 28 vol.% H2. An open-circuit voltage of 1.0 V and maximum power density of 47 mW cm-2 at 565 °C is achieved with the on-chip produced hydrogen at the micro-SOFC membranes.

  6. Nozzle insert for mixed mode fuel injector

    DOEpatents

    Lawrence, Keith E.

    2006-11-21

    A fuel injector includes a homogenous charge nozzle outlet set and a conventional nozzle outlet set controlled respectively, by first and second needle valve members. The homogeneous charged nozzle outlet set is defined by a nozzle insert that is attached to an injector body, which defines the conventional nozzle outlet set. The nozzle insert is a one piece metallic component with a large diameter segment separated from a small diameter segment by an annular engagement surface. One of the needle valve members is guided on an outer surface of the nozzle insert, and the nozzle insert has an interference fit attachment to the injector body.

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

    SciTech Connect

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

    2005-01-01

    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 ºC to ~750 ºC 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.

  8. Thin-Film Solid Oxide Fuel Cells

    NASA Technical Reports Server (NTRS)

    Chen, Xin; Wu, Nai-Juan; Ignatiev, Alex

    2009-01-01

    The development of thin-film solid oxide fuel cells (TFSOFCs) and a method of fabricating them have progressed to the prototype stage. This can result in the reduction of mass, volume, and the cost of materials for a given power level.

  9. Nitrogen oxide abatement by distributed fuel addition

    SciTech Connect

    Wendt, J.O.L.; Mereb, J.B.

    1989-06-20

    A combustor has been designed in order to retard the formation of nitrogen oxides by injection of reburning fuel. The design and the rebuilding of the new combustor was completed. Several new features were incorporated in the new design so that it would last longer. The design and construction of the furnace are discussed in this report. (VC)

  10. Electrocatalyst for alcohol oxidation in fuel cells

    DOEpatents

    Adzic, Radoslav R.; Marinkovic, Nebojsa S.

    2001-01-01

    Binary and ternary electrocatalysts are provided for oxidizing alcohol in a fuel cell. The binary electrocatalyst includes 1) a substrate selected from the group consisting of NiWO.sub.4 or CoWO.sub.4 or a combination thereof, and 2) Group VIII noble metal catalyst supported on the substrate. The ternary electrocatalyst includes 1) a substrate as described above, and 2) a catalyst comprising Group VIII noble metal, and ruthenium oxide or molybdenum oxide or a combination thereof, said catalyst being supported on said substrate.

  11. Generator configuration for solid oxide fuel cells

    DOEpatents

    Reichner, Philip

    1989-01-01

    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.

  12. Sintered electrode for solid oxide fuel cells

    DOEpatents

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

    1999-06-01

    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.

  13. Energy storage in ultrathin solid oxide fuel cells.

    PubMed

    Van Overmeere, Quentin; Kerman, Kian; Ramanathan, Shriram

    2012-07-11

    The power output of hydrogen fuel cells quickly decreases to zero if the fuel supply is interrupted. We demonstrate thin film solid oxide fuel cells with nanostructured vanadium oxide anodes that generate power for significantly longer time than reference porous platinum anode thin film solid oxide fuel cells when the fuel supply is interrupted. The charge storage mechanism was investigated quantitatively with likely identified contributions from the oxidation of the vanadium oxide anode, its hydrogen storage properties, and different oxygen concentration at the electrodes. Fuel cells capable of storing charge even for short periods of time could contribute to ultraminiaturization of power sources for mobile energy.

  14. Comparative study on ammonia oxidation over Ni-based cermet anodes for solid oxide fuel cells

    NASA Astrophysics Data System (ADS)

    Molouk, Ahmed Fathi Salem; Yang, Jun; Okanishi, Takeou; Muroyama, Hiroki; Matsui, Toshiaki; Eguchi, Koichi

    2016-02-01

    In the current work, we investigate the performance of solid oxide fuel cells (SOFCs) with Ni‒yttria-stabilized zirconia (Ni-YSZ) and Ni‒gadolinia-dope ceria (Ni-GDC) cermet anodes fueled with H2 or NH3 in terms of the catalytic activity of ammonia decomposition. The cermet of Ni-GDC shows higher catalytic activity for ammonia decomposition than Ni-YSZ. In response to this, the performance of direct NH3-fueled SOFC improved by using Ni-GDC anode. Moreover, we observe further enhancement in the cell performance and the catalytic activity for ammonia decomposition with applying Ni-GDC anode synthesised by the glycine-nitrate combustion process. These results reveal that the high performance of Ni-GDC anode for the direct NH3-fueled SOFC results from its mixed ionic-electronic conductivity as well as high catalytic activity for ammonia decomposition.

  15. Melting behavior of mixed U-Pu oxides under oxidizing conditions

    NASA Astrophysics Data System (ADS)

    Strach, Michal; Manara, Dario; Belin, Renaud C.; Rogez, Jacques

    2016-05-01

    In order to use mixed U-Pu oxide ceramics in present and future nuclear reactors, their physical and chemical properties need to be well determined. The behavior of stoichiometric (U,Pu)O2 compounds is relatively well understood, but the effects of oxygen stoichiometry on the fuel performance and stability are often still obscure. In the present work, a series of laser melting experiments were carried out to determine the impact of an oxidizing atmosphere, and in consequence the departure from a stoichiometric composition on the melting behavior of six mixed uranium plutonium oxides with Pu content ranging from 14 to 62 wt%. The starting materials were disks cut from sintered stoichiometric pellets. For each composition we have performed two laser melting experiments in pressurized air, each consisting of four shots of different duration and intensity. During the experiments we recorded the temperature at the surface of the sample with a pyrometer. Phase transitions were qualitatively identified with the help of a reflected blue laser. The observed phase transitions occur at a systematically lower temperature, the lower the Pu content of the studied sample. It is consistent with the fact that uranium dioxide is easily oxidized at elevated temperatures, forming chemical species rich in oxygen, which melt at a lower temperature and are more volatile. To our knowledge this campaign is a first attempt to quantitatively determine the effect of O/M on the melting temperature of MOX.

  16. Air electrode composition for solid oxide fuel cell

    DOEpatents

    Kuo, Lewis; Ruka, Roswell J.; Singhal, Subhash C.

    1999-01-01

    An air electrode composition for a solid oxide fuel cell is disclosed. The air electrode material is based on lanthanum manganite having a perovskite-like crystal structure ABO.sub.3. The A-site of the air electrode composition comprises a mixed lanthanide in combination with rare earth and alkaline earth dopants. The B-site of the composition comprises Mn in combination with dopants such as Mg, Al, Cr and Ni. The mixed lanthanide comprises La, Ce, Pr and, optionally, Nd. The rare earth A-site dopants preferably comprise La, Nd or a combination thereof, while the alkaline earth A-site dopant preferably comprises Ca. The use of a mixed lanthanide substantially reduces raw material costs in comparison with compositions made from high purity lanthanum starting materials. The amount of the A-site and B-site dopants is controlled in order to provide an air electrode composition having a coefficient of thermal expansion which closely matches that of the other components of the solid oxide fuel cell.

  17. Air electrode composition for solid oxide fuel cell

    DOEpatents

    Kuo, L.; Ruka, R.J.; Singhal, S.C.

    1999-08-03

    An air electrode composition for a solid oxide fuel cell is disclosed. The air electrode material is based on lanthanum manganite having a perovskite-like crystal structure ABO{sub 3}. The A-site of the air electrode composition comprises a mixed lanthanide in combination with rare earth and alkaline earth dopants. The B-site of the composition comprises Mn in combination with dopants such as Mg, Al, Cr and Ni. The mixed lanthanide comprises La, Ce, Pr and, optionally, Nd. The rare earth A-site dopants preferably comprise La, Nd or a combination thereof, while the alkaline earth A-site dopant preferably comprises Ca. The use of a mixed lanthanide substantially reduces raw material costs in comparison with compositions made from high purity lanthanum starting materials. The amount of the A-site and B-site dopants is controlled in order to provide an air electrode composition having a coefficient of thermal expansion which closely matches that of the other components of the solid oxide fuel cell. 3 figs.

  18. Fabrication of solid oxide fuel cell by electrochemical vapor deposition

    NASA Astrophysics Data System (ADS)

    Riley, Brian; Szreders, Bernard E.

    1988-04-01

    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 (approx. 1100 to 1300 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 and 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.

  19. Fabrication of solid oxide fuel cell by electrochemical vapor deposition

    DOEpatents

    Brian, Riley; Szreders, Bernard E.

    1989-01-01

    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.

  20. Fabrication of solid oxide fuel cell by electrochemical vapor deposition

    DOEpatents

    Riley, B.; Szreders, B.E.

    1988-04-26

    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.

  1. Fuel-Air Mixing and Combustion in Scramjets

    NASA Technical Reports Server (NTRS)

    Drummond, J. P.; Diskin, Glenn S.; Cutler, A. D.

    2002-01-01

    Activities in the area of scramjet fuel-air mixing and combustion associated with the Research and Technology Organization Working Group on Technologies for Propelled Hypersonic Flight are described. Work discussed in this paper has centered on the design of two basic experiments for studying the mixing and combustion of fuel and air in a scramjet. Simulations were conducted to aid in the design of these experiments. The experimental models were then constructed, and data were collected in the laboratory. Comparison of the data from a coaxial jet mixing experiment and a supersonic combustor experiment with a combustor code were then made and described. This work was conducted by NATO to validate combustion codes currently employed in scramjet design and to aid in the development of improved turbulence and combustion models employed by the codes.

  2. Chemical Characterization and Reactivity of Fuel-Oxidizer Reaction Product

    NASA Technical Reports Server (NTRS)

    David, Dennis D.; Dee, Louis A.; Beeson, Harold D.

    1997-01-01

    Fuel-oxidizer reaction product (FORP), the product of incomplete reaction of monomethylhydrazine and nitrogen tetroxide propellants prepared under laboratory conditions and from firings of Shuttle Reaction Control System thrusters, has been characterized by chemical and thermal analysis. The composition of FORP is variable but falls within a limited range of compositions that depend on three factors: the fuel-oxidizer ratio at the time of formation; whether the composition of the post-formation atmosphere is reducing or oxidizing; and the reaction or post-reaction temperature. A typical composition contains methylhydrazinium nitrate, ammonium nitrate, methylammonium nitrate, and trace amounts of hydrazinium nitrate and 1,1-dimethylhydrazinium nitrate. Thermal decomposition reactions of the FORP compositions used in this study were unremarkable. Neither the various compositions of FORP, the pure major components of FORP, nor mixtures of FORP with propellant system corrosion products showed any unusual thermal activity when decomposed under laboratory conditions. Off-limit thruster operations were simulated by rapid mixing of liquid monomethylhydrazine and liquid nitrogen tetroxide in a confined space. These tests demonstrated that monomethylhydrazine, methylhydrazinium nitrate, ammonium nitrate, or Inconel corrosion products can induce a mixture of monomethylhydrazine and nitrogen tetroxide to produce component-damaging energies. Damaging events required FORP or metal salts to be present at the initial mixing of monomethylhydrazine and nitrogen tetroxide.

  3. Solid oxide fuel cell having monolithic core

    DOEpatents

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

    1983-10-12

    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.

  4. Analysis of Fuel Vaporization, Fuel-Air Mixing, and Combustion in Integrated Mixer-Flame Holders

    NASA Technical Reports Server (NTRS)

    Deur, J. M.; Cline, M. C.

    2004-01-01

    Requirements to limit pollutant emissions from the gas turbine engines for the future High-Speed Civil Transport (HSCT) have led to consideration of various low-emission combustor concepts. One such concept is the Integrated Mixer-Flame Holder (IMFH). This report describes a series of IMFH analyses performed with KIVA-II, a multi-dimensional CFD code for problems involving sprays, turbulence, and combustion. To meet the needs of this study, KIVA-II's boundary condition and chemistry treatments are modified. The study itself examines the relationships between fuel vaporization, fuel-air mixing, and combustion. Parameters being considered include: mixer tube diameter, mixer tube length, mixer tube geometry (converging-diverging versus straight walls), air inlet velocity, air inlet swirl angle, secondary air injection (dilution holes), fuel injection velocity, fuel injection angle, number of fuel injection ports, fuel spray cone angle, and fuel droplet size. Cases are run with and without combustion to examine the variations in fuel-air mixing and potential for flashback due to the above parameters. The degree of fuel-air mixing is judged by comparing average, minimum, and maximum fuel/air ratios at the exit of the mixer tube, while flame stability is monitored by following the location of the flame front as the solution progresses from ignition to steady state. Results indicate that fuel-air mixing can be enhanced by a variety of means, the best being a combination of air inlet swirl and a converging-diverging mixer tube geometry. With the IMFH configuration utilized in the present study, flashback becomes more common as the mixer tube diameter is increased and is instigated by disturbances associated with the dilution hole flow.

  5. Effect of swirler-mounted mixing venturi on emissions of flame-tube combustor using jet A fuel

    NASA Technical Reports Server (NTRS)

    Ercegovic, D. B.

    1979-01-01

    Six headplate modules in a flame-tube combustor were evaluated. Unburned hydrocarbons, carbon monoxide, and oxides of nitrogen were measured for three types of fuel injectors both with and without a mixing venturi. Tests were conducted using jet A fuel at an inlet pressure of 0.69 megapascal, an inlet temperature of 478 K, and an isothermal static pressure drop of 3 percent. Oxides of nitrogen were reduced by over 50 percent with a mixing venturi with no performance penalties in either other gaseous emissions or pressure drop.

  6. Glass Mica Composite Seals for Solid Oxide Fuel Cells

    SciTech Connect

    Chou, Y S.; Stevenson, Jeffry W.; Singh, Prabhakar

    2005-07-20

    A novel glass-mica composite seal was developed based on the previous concept of ''infiltrated'' mica seals for solid oxide fuel cells. A Ba-Al-Ca silicate sealing glass was mixed with mica flakes to form the glass-mica composite seals. The glass-mica composite seals were tested thermal cycle stability in terms of the high temperature leakage and compressive stresses. Post mortem analyses were used to characterize the fracture and leak path of the glass-mica composite seals.

  7. Fuel injection and mixing systems having piezoelectric elements and methods of using the same

    DOEpatents

    Mao, Chien-Pei; Short, John; Klemm, Jim; Abbott, Royce; Overman, Nick; Pack, Spencer; Winebrenner, Audra

    2011-12-13

    A fuel injection and mixing system is provided that is suitable for use with various types of fuel reformers. Preferably, the system includes a piezoelectric injector for delivering atomized fuel, a gas swirler, such as a steam swirler and/or an air swirler, a mixing chamber and a flow mixing device. The system utilizes ultrasonic vibrations to achieve fuel atomization. The fuel injection and mixing system can be used with a variety of fuel reformers and fuel cells, such as SOFC fuel cells.

  8. Compost in plant microbial fuel cell for bioelectricity generation.

    PubMed

    Moqsud, M A; Yoshitake, J; Bushra, Q S; Hyodo, M; Omine, K; Strik, David

    2015-02-01

    Recycling of organic waste is an important topic in developing countries as well as developed countries. Compost from organic waste has been used for soil conditioner. In this study, an experiment has been carried out to produce green energy (bioelectricity) by using paddy plant microbial fuel cells (PMFCs) in soil mixed with compost. A total of six buckets filled with the same soil were used with carbon fiber as the electrodes for the test. Rice plants were planted in five of the buckets, with the sixth bucket containing only soil and an external resistance of 100 ohm was used for all cases. It was observed that the cells with rice plants and compost showed higher values of voltage and power density with time. The highest value of voltage showed around 700 mV when a rice plant with 1% compost mixed soil was used, however it was more than 95% less in the case of no rice plant and without compost. Comparing cases with and without compost but with the same number of rice plants, cases with compost depicted higher voltage to as much as 2 times. The power density was also 3 times higher when the compost was used in the paddy PMFCs which indicated the influence of compost on bio-electricity generation.

  9. Holdup measurement for nuclear fuel manufacturing plants

    SciTech Connect

    Zucker, M.S.; Degen, M.; Cohen, I.; Gody, A.; Summers, R.; Bisset, P.; Shaub, E.; Holody, D.

    1981-07-13

    The assay of nuclear material holdup in fuel manufacturing plants is a laborious but often necessary part of completing the material balance. A range of instruments, standards, and a methodology for assaying holdup has been developed. The objectives of holdup measurement are ascertaining the amount, distribution, and how firmly fixed the SNM is. The purposes are reconciliation of material unbalance during or after a manufacturing campaign or plant decommissioning, to decide security requirements, or whether further recovery efforts are justified.

  10. Fuel-Air Mixing and Combustion in Scramjets. Chapter 6

    NASA Technical Reports Server (NTRS)

    Drummond, J. Philip; Diskin, Glenn S.; Cutler, Andrew D.

    2006-01-01

    At flight speeds, the residence time for atmospheric air ingested into a scramjet inlet and exiting from the engine nozzle is on the order of a millisecond. Therefore, fuel injected into the air must efficiently mix within tens of microseconds and react to release its energy in the combustor. The overall combustion process should be mixing controlled to provide a stable operating environment; in reality, however, combustion in the upstream portion of the combustor, particularly at higher Mach numbers, is kinetically controlled where ignition delay times are on the same order as the fluid scale. Both mixing and combustion time scales must be considered in a detailed study of mixing and reaction in a scramjet to understand the flow processes and to ultimately achieve a successful design. Although the geometric configuration of a scramjet is relatively simple compared to a turbomachinery design, the flow physics associated with the simultaneous injection of fuel from multiple injector configurations, and the mixing and combustion of that fuel downstream of the injectors is still quite complex. For this reason, many researchers have considered the more tractable problem of a spatially developing, primarily supersonic, chemically reacting mixing layer or jet that relaxes only the complexities introduced by engine geometry. All of the difficulties introduced by the fluid mechanics, combustion chemistry, and interactions between these phenomena can be retained in the reacting mixing layer, making it an ideal problem for the detailed study of supersonic reacting flow in a scramjet. With a good understanding of the physics of the scramjet internal flowfield, the designer can then return to the actual scramjet geometry with this knowledge and apply engineering design tools that more properly account for the complex physics. This approach will guide the discussion in the remainder of this section.

  11. Direct FuelCell/Turbine Power Plant

    SciTech Connect

    Hossein Ghezel-Ayagh

    2008-09-30

    This report summarizes the progress made in development of Direct FuelCell/Turbine (DFC/T{reg_sign}) power plants for generation of clean power at very high efficiencies. The DFC/T system employs an indirectly heated Turbine Generator to supplement fuel cell generated power. The concept extends the high efficiency of the fuel cell by utilizing the fuel cell's byproduct heat in a Brayton cycle. Features of the DFC/T system include: electrical efficiencies of up to 75% on natural gas, minimal emissions, reduced carbon dioxide release to the environment, simplicity in design, direct reforming internal to the fuel cell, and potential cost competitiveness with existing combined cycle power plants. Proof-of-concept tests using a sub-MW-class DFC/T power plant at FuelCell Energy's (FCE) Danbury facility were conducted to validate the feasibility of the concept and to measure its potential for electric power production. A 400 kW-class power plant test facility was designed and retrofitted to conduct the tests. The initial series of tests involved integration of a full-size (250 kW) Direct FuelCell stack with a 30 kW Capstone microturbine. The operational aspects of the hybrid system in relation to the integration of the microturbine with the fuel cell, process flow and thermal balances, and control strategies for power cycling of the system, were investigated. A subsequent series of tests included operation of the sub-MW Direct FuelCell/Turbine power plant with a Capstone C60 microturbine. The C60 microturbine extended the range of operation of the hybrid power plant to higher current densities (higher power) than achieved in initial tests using the 30kW microturbine. The proof-of-concept test results confirmed the stability and controllability of operating a fullsize (250 kW) fuel cell stack in combination with a microturbine. Thermal management of the system was confirmed and power plant operation, using the microturbine as the only source of fresh air supply to the

  12. Nitrogen oxide abatement by distributed fuel addition

    SciTech Connect

    Wendt, J.O.L.; Meraab, J.

    1988-03-25

    The purpose of this project is to develop techniques for nitrogen oxides abatement by distributed fuel addition. The major nitrogen oxide of interest is Nitric Oxide (NO), a precursor to premature forest damage and to acid rain. Recently interest has also been evoked with respect to an additional oxide of nitrogen, namely Nitrous Oxide (N{sub 2}O). Therefore, abatement measures for NO{sub x} are being investigated to determine their influence on N{sub 2}O as well. This report briefly describes the significance of N{sub 2}O emissions to the environment and the urgent need to develop techniques that can reduce emissions of both NO and N{sub 2}O. Reburning through distributed fuel addition may be an effective technique for NO{sub x} (mainly NO) emission control as described in the previous quarterly report. Reburning may also be effective in reducing N{sub 2}O levels. A technique for N{sub 2}O measurement by gas chromatography/electron capture detection was developed during this quarter, and is described in this report. This analysis technique will be used in the proposed experimental study to investigate the effectiveness of reburning on N{sub 2}O control.

  13. Open end protection for solid oxide fuel cells

    DOEpatents

    Zafred, Paolo R.; Dederer, Jeffrey T.; Tomlins, Gregory W.; Toms, James M.; Folser, George R.; Schmidt, Douglas S.; Singh, Prabhakar; Hager, Charles A.

    2001-01-01

    A solid oxide fuel cell (40) having a closed end (44) and an open end (42) operates in a fuel cell generator (10) where the fuel cell open end (42) of each fuel cell contains a sleeve (60, 64) fitted over the open end (42), where the sleeve (60, 64) extends beyond the open end (42) of the fuel cell (40) to prevent degradation of the interior air electrode of the fuel cell by fuel gas during operation of the generator (10).

  14. Catalysis in solid oxide fuel cells.

    PubMed

    Gorte, R J; Vohs, J M

    2011-01-01

    Solid oxide fuel cells (SOFCs) and solid oxide electrolyzers (SOEs) hold much promise as highly efficient devices for the direct interconversion of chemical and electrical energy. Commercial application of these devices, however, requires further improvements in their performance and stability. Because the performance of SOFC and SOE electrodes depends on their microstructures, electronic and ionic conductivities, and chemical reactivities, the needed improvements require the expertise of various disciplines, with catalytic science playing an important role. Highly active and thermally stable catalysts are required to limit the internal losses in the devices, increase the range of fuels they can use, and decrease the temperatures at which they operate. In this article we review some of the most important recent advances in catalysis for SOFC and SOE electrodes and highlight additional improvements that are needed.

  15. Computational modeling of solid oxide fuel cell

    NASA Astrophysics Data System (ADS)

    Penmetsa, Satish Kumar

    In the ongoing search for alternative and environmentally friendly power generation facilities, the solid oxide fuel cell (SOFC) is considered one of the prime candidates for the next generation of energy conversion devices due to its capability to provide environmentally friendly and highly efficient power generation. Moreover, SOFCs are less sensitive to composition of fuel as compared to other types of fuel cells, and internal reforming of the hydrocarbon fuel cell can be performed because of higher operating temperature range of 700°C--1000°C. This allows us to use different types of hydrocarbon fuels in SOFCs. The objective of this study is to develop a three-dimensional computational model for the simulation of a solid oxide fuel cell unit to analyze the complex internal transport mechanisms and sensitivity of the cell with different operating conditions, and also to develop SOFC with higher operating current density with a more uniform gas distributions in the electrodes and with lower ohmic losses. This model includes mass transfer processes due to convection and diffusion in the gas flow channels based on the Navier-Stokes equations as well as combined diffusion and advection in electrodes using Brinkman's hydrodynamic equation and associated electrochemical reactions in the trilayer of the SOFC. Gas transport characteristics in terms of three-dimensional spatial distributions of reactant gases and their effects on electrochemical reactions at the electrode-electrolyte interface, and in the resulting polarizations, are evaluated for varying pressure conditions. Results show the significance of the Brinkman's hydrodynamic model in electrodes to achieve more uniform gas concentration distributions while using a higher operating pressure and over a higher range of operating current densities.

  16. Solid oxide fuel cell having monolithic core

    DOEpatents

    Ackerman, John P.; Young, John E.

    1984-01-01

    A solid oxide fuel cell 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, and each interconnect wall consists of thin layers of the cathode and anode materials sandwiching a thin layer of interconnect 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 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 0.002-0.01 cm thick; and each layer of the cathode and anode materials is of the order of 0.002-0.05 cm thick.

  17. Development of molten carbonate fuel cell power plant technology

    NASA Astrophysics Data System (ADS)

    Healy, H. C.; Sanderson, R. A.; Wertheim, F. J.; Farris, P. F.; Mientek, A. P.; Maricle, D. L.; Briggs, T. A.; Preston, J. L., Jr.; Louis, G. A.; Abrams, M. L.

    1980-08-01

    During this quarter, effort was continued in all four major task areas: system studies to define the reference power plant design; cell and stack design, development and verification; preparation for fabrication and testing of the full-scale prototype stack; and developing the capability for operation of stacks on coal-derived gas. Preliminary module and cell stack design requirements were completed. Fuel processor characterization was completed. Design approaches for full-scale stack busbars and electrical isolation of reactant manifolds and reactant piping were defined. Preliminary design requirements were completed for the anode. Conductive nickel oxide for cathode fabrication was made by oxidation and lithiation of porous nickel sheet stock. A method of mechanizing the tape casting process for increased production rates was successfully demonstrated. Theoretical calculations indicated that hydrogen cyanide and ammonia, when present as impurities in the stack fuel gas, will have no harmful effects. Laboratory experiments using higher than anticipated levels of ethylene showed no harmful effects.

  18. Formation of alumina-ceria mixed oxide in model systems

    NASA Astrophysics Data System (ADS)

    Skála, Tomáš; Tsud, Nataliya; Prince, Kevin C.; Matolín, Vladimír

    2011-02-01

    Interaction of aluminium with cerium oxide was studied by photoelectron spectroscopy of Al/CeO2(1 1 1) and CeO2/Al(1 1 1) model systems. It was found in both cases that metallic aluminium was immediately oxidized, CeO2 was partially reduced and a mixed oxide with cerium present as Ce3+ was formed. The compound is probably cerium aluminate CeAlO3 mixed with Al2O3 or Ce2O3. In both cases the intermixing was limited by the diffusion of aluminium into ceria. The excess of deposited material above this limit formed AlOx and CeO2 overlayers on the top of the mixed oxide + aluminate/CeO2 and mixed oxide + aluminate/Al films, respectively.

  19. Life optimization for fossil fuel power plants

    SciTech Connect

    McNaughton, W.P.; Richman, R.H. ); Parker, J.D.; McMinn, A. ); Bell, R.J. ); McCabe, P.; Leake, W.H. Jr. ); Dimmer, J.P.; Damon, J.E. ); Brusger, E.C.; Farber, M.

    1990-11-01

    During 1985 and 1986, EPRI funded several major studies of aging fossil-fuel power plants. These were aimed both at evaluation and planning on the plant level (life optimization), and condition assessment of individual components (life assessment). The experience gained during the execution of these projects, along with available international experience on the optimized use of existing power plants, was integrated in Generic Guidelines for the Life Extension of Fossil Fuel Power Plants,'' issued in November 1986 (CS-4778). These guidelines advocated the assessment of residual component life in increasingly detailed stages, the phased evaluation and refurbishment of equipment, the importance of integrated planning, and the requirement for application of data management techniques. To extend the procedures and methods presented in those generic guidelines, and to demonstrate the potential benefits of a formalized approach to the consideration of fossil fuel power plant evaluation, the Electric Power Research Institute initiated a technology transfer demonstration project, RP2596-10. This report provides a summary of the activities in that demonstration project. One of the tools that was developed during the project was a compilation of the condition assessment of 25 critical and major components. This report includes an overview of the Component Condition Assessment Guidelines, as well as other tools and analysis methods that were developed during the project. The project also served as a review of the application of the methods and procedures presented in the basic guidelines document; therefore, this report also includes an evaluation and suggested refinements of the generic guidelines.

  20. Optimal design of proportional-integral controllers for stand-alone solid oxide fuel cell power plant using differential evolution algorithm.

    PubMed

    Ahmed, Ashik; Ullah, Md Shahid

    2016-01-01

    This paper proposes the application of differential evolution (DE) algorithm for the optimal tuning of proportional-integral (PI) controller designed to improve the small signal dynamic response of a stand-alone solid oxide fuel cell (SOFC) system. The small signal model of the study system is derived and considered for the controller design as the target here is to track small variations in SOFC load current. Two PI controllers are incorporated in the feedback loops of hydrogen and oxygen partial pressures with an aim to improve the small signal dynamic responses. The controller design problem is formulated as the minimization of an eigenvalue based objective function where the target is to find out the optimal gains of the PI controllers in such a way that the discrepancy of the obtained and desired eigenvalues are minimized. Eigenvalue and time domain simulations are presented for both open-loop and closed loop systems. To test the efficacy of DE over other optimization tools, the results obtained with DE are compared with those obtained by particle swarm optimization (PSO) algorithm and invasive weed optimization (IWO) algorithm. Three different types of load disturbances are considered for the time domain based results to investigate the performances of different optimizers under different sorts of load variations. Moreover, non-parametric statistical analyses, namely, one sample Kolmogorov-Smirnov (KS) test and paired sample t test are used to identify the statistical advantage of one optimizer over the other for the problem under study. The presented results suggest the supremacy of DE over PSO and IWO in finding the optimal solution. PMID:27066389

  1. Optimal design of proportional-integral controllers for stand-alone solid oxide fuel cell power plant using differential evolution algorithm.

    PubMed

    Ahmed, Ashik; Ullah, Md Shahid

    2016-01-01

    This paper proposes the application of differential evolution (DE) algorithm for the optimal tuning of proportional-integral (PI) controller designed to improve the small signal dynamic response of a stand-alone solid oxide fuel cell (SOFC) system. The small signal model of the study system is derived and considered for the controller design as the target here is to track small variations in SOFC load current. Two PI controllers are incorporated in the feedback loops of hydrogen and oxygen partial pressures with an aim to improve the small signal dynamic responses. The controller design problem is formulated as the minimization of an eigenvalue based objective function where the target is to find out the optimal gains of the PI controllers in such a way that the discrepancy of the obtained and desired eigenvalues are minimized. Eigenvalue and time domain simulations are presented for both open-loop and closed loop systems. To test the efficacy of DE over other optimization tools, the results obtained with DE are compared with those obtained by particle swarm optimization (PSO) algorithm and invasive weed optimization (IWO) algorithm. Three different types of load disturbances are considered for the time domain based results to investigate the performances of different optimizers under different sorts of load variations. Moreover, non-parametric statistical analyses, namely, one sample Kolmogorov-Smirnov (KS) test and paired sample t test are used to identify the statistical advantage of one optimizer over the other for the problem under study. The presented results suggest the supremacy of DE over PSO and IWO in finding the optimal solution.

  2. Apparatus and method for mixing fuel in a gas turbine nozzle

    DOEpatents

    Johnson, Thomas Edward; Ziminsky, Willy Steve; Berry, Jonathan Dwight

    2014-08-12

    A nozzle includes a fuel plenum and an air plenum downstream of the fuel plenum. A primary fuel channel includes an inlet in fluid communication with the fuel plenum and a primary air port in fluid communication with the air plenum. Secondary fuel channels radially outward of the primary fuel channel include a secondary fuel port in fluid communication with the fuel plenum. A shroud circumferentially surrounds the secondary fuel channels. A method for mixing fuel and air in a nozzle prior to combustion includes flowing fuel to a fuel plenum and flowing air to an air plenum downstream of the fuel plenum. The method further includes injecting fuel from the fuel plenum through a primary fuel passage, injecting fuel from the fuel plenum through secondary fuel passages, and injecting air from the air plenum through the primary fuel passage.

  3. Solid oxide fuel cell electrode characterization and improvement for fuel flexibility and supplemental power production

    NASA Astrophysics Data System (ADS)

    Kellogg, Isaiah Daniel

    2010-03-01

    Solid oxide fuel cells (SOFC) were fabricated and the electrodes tested for their individual catalytic effectiveness in various fuels by exposing each electrode to mixed gas while the opposite electrode was exposed to its respective pure gas. Mixed hydrogen and oxygen gas was successfully utilized as fuel in a single chamber SOFC (SC-SOFC). The conditions at which the porous nickel-yttria-stabilized zirconia (Ni-YSZ) cermet anode performed well did not significantly overlap the conditions at which the La0.8Sr 0.2Fe0.8Co0.2 oxide (LSCF) cathode performed well, but there was significant catalytic activity at both electrodes which increased the open circuit voltage (OCV) beyond that predicted by the Nernst equation. The results of these tests, and future tests of similar format, could be useful in the development of SC-SOFC electrode catalysts. Pyrolytic carbon was used as fuel in a SOFC with a YSZ electrolyte and a bi-layer anode composed of nickel gadolinia-doped ceria (Ni-GDC) and Ni-YSZ. The common problems of bulk shrinkage and emergent porosity in the YSZ layer adjacent to the GDC/YSZ interface were avoided by using an interlayer of porous Ni-YSZ as a buffer anode layer between the electrolyte and the Ni-GDC primary anode. Cells were fabricated from commercially available component powders so that unconventional production methods suggested in the literature were avoided. A cell of similar construction was used with externally applied acetylene flame soot as fuel so that soot captured at the exhaust of a diesel engine could be utilized for secondary power generation in a SOFC while decreasing particulate pollution without the need for filter regeneration.

  4. DIRECT FUEL CELL/TURBINE POWER PLANT

    SciTech Connect

    Hossein Ghezel-Ayagh

    2003-05-27

    The subMW hybrid DFC/T power plant facility was upgraded with a Capstone C60 microturbine and a state-of-the-art full size fuel cell stack. The integration of the larger microturbine extended the capability of the hybrid power plant to operate at high power ratings with a single gas turbine without the need for supplementary air. The objectives of this phase of subMW hybrid power plant tests are to support the development of process and control and to provide the insight for the design of the packaged subMW hybrid demonstration units. The development of the ultra high efficiency multi-MW power plants was focused on the design of 40 MW power plants with efficiencies approaching 75% (LHV of natural gas). The design efforts included thermodynamic cycle analysis of key gas turbine parameters such as compression ratio.

  5. Fuel cell power plant economic and operational considerations

    NASA Technical Reports Server (NTRS)

    Lance, J. R.

    1984-01-01

    Fuel cell power plants intended for electric utility and cogeneration applications are now in the design and construction stage. This paper describes economic and operational considerations being used in the development and design of plants utilizing air cooled phosphoric acid fuel cells. Fuel cell power plants have some unique characteristics relative to other types of power plants. As a result it was necessary to develop specific definitions of the fuel cell power plant characteristics in order to perform cost of electricity calculations. This paper describes these characteristics and describes the economic analyses used in the Westinghouse fuel cell power plant program.

  6. Monolithic Solid Oxide Fuel Cell development

    NASA Technical Reports Server (NTRS)

    Myles, K. M.; Mcpheeters, C. C.

    1989-01-01

    The Monolithic Solid Oxide Fuel Cell (MSOFC) is an oxide-ceramic structure in which appropriate electronic and ionic conductors are fabricated in a honeycomb shape similar to a block of corrugated paperboard. These electronic and ionic conductors are arranged to provide short conduction paths to minimize resistive losses. The power density achievable with the MSOFC is expected to be about 8 kW/kg or 4 kW/L, at fuel efficienceis over 50 percent, because of small cell size and low resistive losses in the materials. The MSOFC operates in the range of 700 to 1000 C, at which temperatures rapid reform of hydrocarbon fuels is expected within the nickel-YSZ fuel channels. Tape casting and hot roll calendering are used to fabricate the MSOFC structure. The performance of the MSOFC has improved significantly during the course of development. The limitation of this system, based on materials resistance alone without interfacial resistances, is 0.093 ohm-sq cm area-specific resistance (ASR). The current typical performance of MSOFC single cells is characterized by ASRs of about 0.4 to 0.5 ohm-sq cm. With further development the ASR is expected to be reduced below 0.2 ohm-sq cm, which will result in power levels greater than 1.4 W/sq cm. The feasibility of the MSOFC concept was proven, and the performance was dramatically improved. The differences in thermal expansion coefficients and firing shrinkages among the fuel cell materials were minimized. As a result of good matching of these properties, the MSOFC structure was successfully fabricated with few defects, and the system shows excellent promise for development into a practical power source.

  7. SOLID STATE ENERGY CONVERSION ALLIANCE DELPHI SOLID OXIDE FUEL CELL

    SciTech Connect

    Steven Shaffer; Sean Kelly; Subhasish Mukerjee; David Schumann; Gail Geiger; Kevin Keegan; John Noetzel; Larry Chick

    2003-12-08

    The objective of Phase I under this project is to develop a 5 kW Solid Oxide Fuel Cell power system for a range of fuels and applications. During Phase I, the following will be accomplished: Develop and demonstrate technology transfer efforts on a 5 kW stationary distributed power generation system that incorporates steam reforming of natural gas with the option of piped-in water (Demonstration System A). Initiate development of a 5 kW system for later mass-market automotive auxiliary power unit application, which will incorporate Catalytic Partial Oxidation (CPO) reforming of gasoline, with anode exhaust gas injected into an ultra-lean burn internal combustion engine. This technical progress report covers work performed by Delphi from January 1, 2003 to June 30, 2003, under Department of Energy Cooperative Agreement DE-FC-02NT41246. This report highlights technical results of the work performed under the following tasks: Task 1 System Design and Integration; Task 2 Solid Oxide Fuel Cell Stack Developments; Task 3 Reformer Developments; Task 4 Development of Balance of Plant (BOP) Components; Task 5 Manufacturing Development (Privately Funded); Task 6 System Fabrication; Task 7 System Testing; Task 8 Program Management; and Task 9 Stack Testing with Coal-Based Reformate.

  8. Yttria-stabilized zirconia solid oxide electrolyte fuel cells, monolithic solid oxide fuel cells

    SciTech Connect

    Not Available

    1989-01-01

    Small cell size, thin ceramic components, and high operating temperature are the key features of the MSOFC. The small size of individual cells in the monolithic structure increases the active surface area. For example, an MSOFC with channels about 1 mm in diameter has a ratio of active surface area to volume of about 9.4 sq cm/cu cm. This is about seven times the ratio for conventional fuel cells. On this basis alone, an MSOFC with a channel diameter of 1 mm should produce the same power as a conventional fuel cell seven times as large. The high current density of the MSOFC results from the small cell size and ensuing low internal resistance. The current density is high at the fuel inlet end of the fuel channel where the thermodynamic driving force (Nernst potential) is highest. Similarly, the current density is low at the outlet end of the fuel channel where the Nernst potential is lowest. Because of the high operating temperature of the MSOFC (1000{degrees}C),hydrocarbon fuels can be reformed in the fuel channels. The reform reaction produces hydrogen which is consumed by the fuel cell. Catalytic reforming of methane and natural gas within a solid oxide fuel cell has been demonstrated.

  9. Exergy & economic analysis of biogas fueled solid oxide fuel cell systems

    NASA Astrophysics Data System (ADS)

    Siefert, Nicholas S.; Litster, Shawn

    2014-12-01

    We present an exergy and an economic analysis of a power plant that uses biogas produced from a thermophilic anaerobic digester (AD) to fuel a solid oxide fuel cell (SOFC). We performed a 4-variable parametric analysis of the AD-SOFC system in order to determine the optimal design operation conditions, depending on the objective function of interest. We present results on the exergy efficiency (%), power normalized capital cost ( kW-1), and the internal rate of return on investment, IRR, (% yr-1) as a function of the current density, the stack pressure, the fuel utilization, and the total air stoichiometric ratio. To the authors' knowledge, this is the first AD-SOFC paper to include the cost of the AD when conducting economic optimization of the AD-SOFC plant. Our calculations show that adding a new AD-SOFC system to an existing waste water treatment (WWT) plant could yield positives values of IRR at today's average electricity prices and could significantly out-compete other options for using biogas to generate electricity. AD-SOFC systems could likely convert WWT plants into net generators of electricity rather than net consumers of electricity while generating economically viable rates of return on investment if the costs of SOFC systems are within a factor of two of the DOE/SECA cost targets.

  10. Recent progress on minor-actinide-bearing oxide fuel fabrication at CEA Marcoule

    NASA Astrophysics Data System (ADS)

    Lebreton, Florent; Prieur, Damien; Horlait, Denis; Delahaye, Thibaud; Jankowiak, Aurélien; Léorier, Caroline; Jorion, Frédéric; Gavilan, Elisabeth; Desmoulière, François

    2013-07-01

    Partitioning and transmutation (P&T) of minor actinides (MA: americium, neptunium and curium) in fast neutron reactors or accelerator-driven systems is a route envisaged to reduce nuclear waste inventory. Over the years, several modes of P&T were proposed, each being based on the use of dedicated fuels such as inert-matrix fuels, MA-bearing MOX or MA-bearing blankets. In this context, progress on the manufacturing of such fuels is a key-challenge in order to render P&T viable at the industrial scale. Here, MA-bearing oxide fuel fabrication and characterization conducted in the CEA Marcoule Atalante facility is reviewed. A particular attention is also given to the research conducted on uranium-americium mixed-oxides fuels, which are now considered the reference fuels for MA transmutation in France.

  11. Oxidation Kinetics of K Basin Fuel (OCRWM)

    SciTech Connect

    TRIMBLE, D.J.

    2000-09-25

    Oxidation testing of K Basin-stored N Reactor fuel in dry air, moist air, and moist helium provided reaction rate data for the Spent Nuclear Fuel Project. The tests were performed on small samples from two spent nuclear fuel elements retrieved from the closed canisters of the K West Basin. The spent nuclear fuel samples were tested using a thermogravimetric analysis system modified for moist-gas operation to allow testing in moist environments. The tests were run at constant temperature and water vapor pressure. The moist helium tests used 6.5 H a water vapor, producing seventeen data between 75 C and 210 C. Eight of these data were excluded from primary consideration due to testing anomalies and balance drift issues. Regression analysis of the nine acceptable data provided good assurance that the moist-helium results are consistent with literature data within the temperature range of 25 C to 210 C. Concerns about possible oxygen poisoning from air in-leakage and mass transfer limitations on the test data were reviewed. If oxygen poisoning occurred it was not likely to have biased the data sufficiently to change the basic conclusions of comparability to the literature data. Mass transfer limitations did not appear to have had significant effect on the moist-helium data.

  12. Solid Oxide Fuel Cell Systems PVL Line

    SciTech Connect

    Susan Shearer - Stark State College; Gregory Rush - Rolls-Royce Fuel Cell Systems

    2012-05-01

    In July 2010, Stark State College (SSC), received Grant DE-EE0003229 from the U.S. Department of Energy (DOE), Golden Field Office, for the development of the electrical and control systems, and mechanical commissioning of a unique 20kW scale high-pressure, high temperature, natural gas fueled Stack Block Test System (SBTS). SSC worked closely with subcontractor, Rolls-Royce Fuel Cell Systems (US) Inc. (RRFCS) over a 13 month period to successfully complete the project activities. This system will be utilized by RRFCS for pre-commercial technology development and training of SSC student interns. In the longer term, when RRFCS is producing commercial products, SSC will utilize the equipment for workforce training. In addition to DOE Hydrogen, Fuel Cells, and Infrastructure Technologies program funding, RRFCS internal funds, funds from the state of Ohio, and funding from the DOE Solid State Energy Conversion Alliance (SECA) program have been utilized to design, develop and commission this equipment. Construction of the SBTS (mechanical components) was performed under a Grant from the State of Ohio through Ohio's Third Frontier program (Grant TECH 08-053). This Ohio program supported development of a system that uses natural gas as a fuel. Funding was provided under the Department of Energy (DOE) Solid-state Energy Conversion Alliance (SECA) program for modifications required to test on coal synthesis gas. The subject DOE program provided funding for the electrical build, control system development and mechanical commissioning. Performance testing, which includes electrical commissioning, was subsequently performed under the DOE SECA program. Rolls-Royce Fuel Cell Systems is developing a megawatt-scale solid oxide fuel cell (SOFC) stationary power generation system. This system, based on RRFCS proprietary technology, is fueled with natural gas, and operates at elevated pressure. A critical success factor for development of the full scale system is the capability to

  13. Tubular solid oxide fuel cell demonstration activities

    SciTech Connect

    Veyo, S.E.

    1995-08-01

    The development of a viable fuel cell driven electrical power generation system involves not only the development of cell and stack technology, but also the development of the overall system concept, the strategy for control, and the ancillary subsystems. The design requirements used to guide system development must reflect a customer focus in order to evolve a commercial product. In order to obtain useful customer feedback, Westinghouse has practiced the deployment with customers of fully integrated, automatically controlled, packaged solid oxide fuel cell power generation systems. These field units have served to demonstrate to customers first hand the beneficial attributes of the SOFC, to expose deficiencies through experience in order to guide continued development, and to garner real world feedback and data concerning not only cell and stack parameters, but also transportation, installation, permitting and licensing, start-up and shutdown, system alarming, fault detection, fault response, and operator interaction.

  14. Solid oxide fuel cell matrix and modules

    DOEpatents

    Riley, B.

    1988-04-22

    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.

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

    SciTech Connect

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

    1987-01-01

    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.

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

    SciTech Connect

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

    1987-01-01

    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, capital and operating cost estimates, 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.

  17. Tubular solid oxide fuel cell development program

    SciTech Connect

    1995-08-01

    This paper presents an overview of the Westinghouse Solid Oxide Fuel Cell (SOFC) development activities and current program status. The Westinghouse goal is to develop a cost effective cell that can operate for 50,000 to 100,000 hours. Progress toward this goal will be discussed and test results presented for multiple single cell tests which have now successfully exceeded 56,000 hours of continuous power operation at temperature. Results of development efforts to reduce cost and increase power output of tubular SOFCs are described.

  18. Mixing of Pure Air Jets with a Reacting Fuel-Rich Crossflow

    NASA Technical Reports Server (NTRS)

    Leong, M. Y.; Samuelsen, G. S.; Holdeman, J. D.

    1997-01-01

    Jets in a crossflow play an integral role in practical combustion systems such as can and annular gas turbine combustors in conventional systems, and the Rich-burn/Quick-mix/Lean-burn (RQL) combustor utilized in stationary applications and proposed for advanced subsonic and supersonic transports. The success of the RQL combustor rests with the performance of the quick-mixing section that bridges the rich and lean zones. The mixing of jet air with a rich crossflow to bring the reaction to completion in the lean zone must be performed rapidly and thoroughly in order to decrease the extent of near-stoichiometric fluid pocket formation. Fluid pockets at near-stoichiometric equivalence ratios are undesirable because the high temperatures attained accelerate pollutant formation kinetics associated with nitric oxide (NO). The present study develops a model experiment designed to reveal the processes that occur when jet air is introduced into hot effluent emanating from a fuel-rich reaction zone.

  19. Fuel cells 101

    SciTech Connect

    Hirschenhofer, J.H.

    1999-07-01

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

  20. Solid oxide fuel cell generator with removable modular fuel cell stack configurations

    DOEpatents

    Gillett, James E.; Dederer, Jeffrey T.; Zafred, Paolo R.; Collie, Jeffrey C.

    1998-01-01

    A high temperature solid oxide fuel cell generator produces electrical power from oxidation of hydrocarbon fuel gases such as natural gas, or conditioned fuel gases, such as carbon monoxide or hydrogen, with oxidant gases, such as air or oxygen. This electrochemical reaction occurs in a plurality of electrically connected solid oxide fuel cells bundled and arrayed in a unitary modular fuel cell stack disposed in a compartment in the generator container. The use of a unitary modular fuel cell stack in a generator is similar in concept to that of a removable battery. The fuel cell stack is provided in a pre-assembled self-supporting configuration where the fuel cells are mounted to a common structural base having surrounding side walls defining a chamber. Associated generator equipment may also be mounted to the fuel cell stack configuration to be integral therewith, such as a fuel and oxidant supply and distribution systems, fuel reformation systems, fuel cell support systems, combustion, exhaust and spent fuel recirculation systems, and the like. The pre-assembled self-supporting fuel cell stack arrangement allows for easier assembly, installation, maintenance, better structural support and longer life of the fuel cells contained in the fuel cell stack.

  1. Solid oxide fuel cell generator with removable modular fuel cell stack configurations

    DOEpatents

    Gillett, J.E.; Dederer, J.T.; Zafred, P.R.; Collie, J.C.

    1998-04-21

    A high temperature solid oxide fuel cell generator produces electrical power from oxidation of hydrocarbon fuel gases such as natural gas, or conditioned fuel gases, such as carbon monoxide or hydrogen, with oxidant gases, such as air or oxygen. This electrochemical reaction occurs in a plurality of electrically connected solid oxide fuel cells bundled and arrayed in a unitary modular fuel cell stack disposed in a compartment in the generator container. The use of a unitary modular fuel cell stack in a generator is similar in concept to that of a removable battery. The fuel cell stack is provided in a pre-assembled self-supporting configuration where the fuel cells are mounted to a common structural base having surrounding side walls defining a chamber. Associated generator equipment may also be mounted to the fuel cell stack configuration to be integral therewith, such as a fuel and oxidant supply and distribution systems, fuel reformation systems, fuel cell support systems, combustion, exhaust and spent fuel recirculation systems, and the like. The pre-assembled self-supporting fuel cell stack arrangement allows for easier assembly, installation, maintenance, better structural support and longer life of the fuel cells contained in the fuel cell stack. 8 figs.

  2. Stability of solid oxide fuel cell materials

    SciTech Connect

    Armstrong, T.R.; Bates, J.L.; Coffey, G.W.; Pederson, L.R.

    1996-08-01

    Chromite interconnection materials in an SOFC are exposed to both highly oxidizing conditions at the cathode and to highly reducing conditions at the anode. Because such conditions could lead to component failure, the authors have evaluated thermal, electrical, chemical, and structural stabilities of these materials as a function of temperature and oxygen partial pressure. The crystal lattice of the chromites was shown to expand for oxygen partial pressures smaller than 10{sup {minus}10} atm, which could lead to cracking and debonding in an SOFC. Highly substituted lanthanum chromite compositions were the most susceptible to lattice expansion; yttrium chromites showed better dimensional stability by more than a factor of two. New chromite compositions were developed that showed little tendency for lattice expansion under strongly reducing conditions, yet provided a good thermal expansion match to other fuel cell components. Use of these new chromite interconnect compositions should improve long-term SOFC performance, particularly for planar cell configurations. Thermodynamic properties of substituted lanthanum manganite cathode compositions have been determined through measurement of electromotive force as a function of temperature. Critical oxygen decomposition pressures for Sr and Ca-substituted lanthanum manganites were established using cells based on a zirconia electrolyte. Strontium oxide and calcium oxide activities in a lanthanum manganite matrix were determined using cells based on strontium fluoride and calcium fluoride electrolytes, respectively. The compositional range of single-phase behavior of these ABO{sub 3}-type perovskites was established as a function of A/B cation ratios and the extent of acceptor doping. Before this work, very little thermodynamic information was in existence for substituted manganite compositions. Such information is needed to predict the long-term stability of solid oxide fuel cell assemblies.

  3. Solid oxide fuel cell matrix and modules

    DOEpatents

    Riley, Brian

    1990-01-01

    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.

  4. Experiment Safety Assurance Package for the 40- to 52-GWd/MT Burnup Phase of Mixed Oxide Fuel Irradiation in Small I-hole Positions in the Advanced Test Reactor

    SciTech Connect

    S. T. Khericha; R. C. Pedersen

    2003-09-01

    This experiment safety assurance package (ESAP) is a revision of the last mixed uranium and plutonium oxide (MOX) ESAP issued in June 2002). The purpose of this revision is to provide a basis to continue irradiation up to 52 GWd/MT burnup [as predicted by MCNP (Monte Carlo N-Particle) transport code The last ESAP provided basis for irradiation, at a linear heat generation rate (LHGR) no greater than 9 kW/ft, of the highest burnup capsule assembly to 50 GWd/MT. This ESAP extends the basis for irradiation, at a LHGR no greater than 5 kW/ft, of the highest burnup capsule assembly from 50 to 52 GWd/MT.

  5. Analysis of monoclonal antibody oxidation by simple mixed mode chromatography.

    PubMed

    Pavon, Jorge Alexander; Li, Xiaojuan; Chico, Steven; Kishnani, Umesh; Soundararajan, Soundara; Cheung, Jason; Li, Huijuan; Richardson, Daisy; Shameem, Mohammed; Yang, Xiaoyu

    2016-01-29

    Analysis of oxidation of monoclonal antibodies (mAbs) in most cases relies on peptide mapping and LC-MS, which is time consuming and labor-intensive. A robust chromatography based method that is able to resolve and quantitate mAb oxidation variants due to oxidized methionine or tryptophan is highly desired. Here we developed a novel mixed mode chromatography method using the unique property of Sepax Zenix SEC-300MK column to analyze mAb oxidation levels. The separation of oxidized species relied upon the mixed mode of size exclusion and hydrophobic interaction between the resin and antibodies. The chromatography was performed in a regular SEC mobile phase, PBS, containing NaCl at a concentration (0-2.4M) specific for individual antibodies. This method was able to resolve and quantitate the oxidized antibodies as prepeaks, of either methionine-oxidized species induced by the common oxidants TBHP, tryptophan-oxidized species triggered by AAPH, or oxidized species by UV photo-irradiation. The prepeaks were further characterized by SEC-MALLS as monomers and confirmed by LC-MS as oxidized antibody variants with a mass increase of 16 or 32Da. This method has been successfully applied to monitor multiple monoclonal antibodies of IgG1, IgG2, and IgG4 subclasses. PMID:26774436

  6. Survey of US fuel ethanol plants.

    PubMed

    Saunders, J A; Rosentrater, K A

    2009-07-01

    The ethanol industry is growing in response to increased consumer demands for fuel as well as the renewable fuel standard. Corn ethanol processing creates the following products: 1/3 ethanol, 1/3 distillers grains, and 1/3 carbon dioxide. As the production of ethanol increases so does the generation of its coproducts, and viable uses continually need to be developed. A survey was mailed to operational US ethanol plants to determine current practices. It inquired about processes, equipment used, end products, and desired future directions for coproducts. Results indicated that approximately one-third of plant managers surveyed expressed a willingness to alter current drying time and temperature if it could result in a higher quality coproduct. Other managers indicated hesitation, based on lack of economic incentives, potential cost and return, and capital required. Respondents also reported the desire to use their coproducts in some of the following products: fuels, extrusion, pellets, plastics, and human food applications. These results provide a snapshot of the industry, and indicate that operational changes to the current production of DDGS must be based upon the potential for positive economic returns.

  7. Tubular screen electrical connection support for solid oxide fuel cells

    DOEpatents

    Tomlins, Gregory W.; Jaszcar, Michael P.

    2002-01-01

    A solid oxide fuel assembly is made of fuel cells (16, 16', 18, 24, 24', 26), each having an outer interconnection layer (36) and an outer electrode (28), which are disposed next to each other with rolled, porous, hollow, electrically conducting metal mesh conductors (20, 20') between the fuel cells, connecting the fuel cells at least in series along columns (15, 15') and where there are no metal felt connections between any fuel cells.

  8. Fuel breaks affect nonnative species abundance in Californian plant communities

    USGS Publications Warehouse

    Merriam, K.E.; Keeley, J.E.; Beyers, J.L.

    2006-01-01

    We evaluated the abundance of nonnative plants on fuel breaks and in adjacent untreated areas to determine if fuel treatments promote the invasion of nonnative plant species. Understanding the relationship between fuel treatments and nonnative plants is becoming increasingly important as federal and state agencies are currently implementing large fuel treatment programs throughout the United States to reduce the threat of wildland fire. Our study included 24 fuel breaks located across the State of California. We found that nonnative plant abundance was over 200% higher on fuel breaks than in adjacent wildland areas. Relative nonnative cover was greater on fuel breaks constructed by bulldozers (28%) than on fuel breaks constructed by other methods (7%). Canopy cover, litter cover, and duff depth also were significantly lower on fuel breaks constructed by bulldozers, and these fuel breaks had significantly more exposed bare ground than other types of fuel breaks. There was a significant decline in relative nonnative cover with increasing distance from the fuel break, particularly in areas that had experienced more numerous fires during the past 50 years, and in areas that had been grazed. These data suggest that fuel breaks could provide establishment sites for nonnative plants, and that nonnatives may invade surrounding areas, especially after disturbances such as fire or grazing. Fuel break construction and maintenance methods that leave some overstory canopy and minimize exposure of bare ground may be less likely to promote nonnative plants. ?? 2006 by the Ecological Society of America.

  9. Direct internal reforming of hydrocarbon fuels in solid oxide fuel cells

    NASA Astrophysics Data System (ADS)

    Zhan, Zhongliang

    2005-07-01

    The direct operation of solid oxide fuel cells (SOFCs) on hydrocarbon fuels is desired since it could reduce power plant size, weight and complexity. The primary challenge is to find effective means through which anode-coking could be suppressed or avoided. Throughout the research, conventional Ni-anode supported SOFCs were employed because they provide high power densities and are being actively developed for commercial applications. Various strategies were used to reduce or avoid anode-coking during the SOFC operation. Firstly, air or CO2/H2O was added to hydrocarbon fuels, such that coking was less thermodynamically favorable, and the resulting internal partial oxidation or dry/steam reforming reactions provided H 2 and CO to the fuel cell. For example, for low hydrocarbons like propane, coke-free operation was achieved on 8% yttrium-stabilized zirconia (YSZ) electrolyte SOFCs via internal partial oxidation, yielding stable and high power densities, e.g. 0.7 W·cm-2 at 790°C. Secondly, a novel design for hydrocarbon fueled SOFCs was proposed, i.e. a separate supported catalyst (Ru-CeO2) layer was placed against the anode side. The catalyst layer provided good catalytic activity for the hydrocarbon reforming reactions, while the nickel-based anode was retained to provide excellent electrochemical activity for the oxidation of the hydrogen and carbon monoxide reforming products. For heavy hydrocarbons like iso-octane, the catalyst layer was crucial far allowing stable cell operation without coking. The lack of coking at the Ni-YSZ anode can be explained by reforming at the Ru-Ceria catalyst layer, which eliminated most of the hydrocarbon species before the fuel reached the anode. A key element of this strategy was the choice of a catalyst metal, Ru, that promotes hydrocarbon reforming but does not itself cause coking. Thirdly, reduced-temperature SOFCs with thin samarium-doped Ceria (SDC) electrolytes were developed; these devices have potentially improved

  10. 26. Evening view of concrete mixing plant, concrete placement tower, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    26. Evening view of concrete mixing plant, concrete placement tower, cableway tower, power line and derrick. Photographer unknown, 1927. Source: MWD. - Waddell Dam, On Agua Fria River, 35 miles northwest of Phoenix, Phoenix, Maricopa County, AZ

  11. 14. VIEW OF DAM SITE, LOOKING SOUTH (DOWNSTREAM). MIXING PLANT ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    14. VIEW OF DAM SITE, LOOKING SOUTH (DOWNSTREAM). MIXING PLANT IS VISIBLE AT RIGHT, COFFER DAM IS UPSTREAM OF PLACING TOWER. EAST DOME IS VISIBLE AT LEFT OF TOWER, c. 1927 - Coolidge Dam, Gila River, Peridot, Gila County, AZ

  12. System modeling of an air-independent solid oxide fuel cell system for unmanned undersea vehicles

    NASA Astrophysics Data System (ADS)

    Burke, A. Alan; Carreiro, Louis G.

    To examine the feasibility of a solid oxide fuel cell (SOFC)-powered unmanned undersea vehicle (UUV), a system level analysis is presented that projects a possible integration of the SOFC stack, fuel steam reformer, fuel/oxidant storage and balance of plant components into a 21-in. diameter UUV platform. Heavy hydrocarbon fuel (dodecane) and liquid oxygen (LOX) are chosen as the preferred reactants. A maximum efficiency of 45% based on the lower heating value of dodecane was calculated for a system that provides 2.5 kW for 40 h. Heat sources and sinks have been coupled to show viable means of thermal management. The critical design issues involve proper recycling of exhaust steam from the fuel cell back into the reformer and effective use of the SOFC stack radiant heat for steam reformation of the hydrocarbon fuel.

  13. Dynamic simulation of a direct carbonate fuel cell power plant

    SciTech Connect

    Ernest, J.B.; Ghezel-Ayagh, H.; Kush, A.K.

    1996-12-31

    Fuel Cell Engineering Corporation (FCE) is commercializing a 2.85 MW Direct carbonate Fuel Cell (DFC) power plant. The commercialization sequence has already progressed through construction and operation of the first commercial-scale DFC power plant on a U.S. electric utility, the 2 MW Santa Clara Demonstration Project (SCDP), and the completion of the early phases of a Commercial Plant design. A 400 kW fuel cell stack Test Facility is being built at Energy Research Corporation (ERC), FCE`s parent company, which will be capable of testing commercial-sized fuel cell stacks in an integrated plant configuration. Fluor Daniel, Inc. provided engineering, procurement, and construction services for SCDP and has jointly developed the Commercial Plant design with FCE, focusing on the balance-of-plant (BOP) equipment outside of the fuel cell modules. This paper provides a brief orientation to the dynamic simulation of a fuel cell power plant and the benefits offered.

  14. Life Cycle Cost Analysis of Ready Mix Concrete Plant

    NASA Astrophysics Data System (ADS)

    Topkar, V. M.; Duggar, A. R.; Kumar, A.; Bonde, P. P.; Girwalkar, R. S.; Gade, S. B.

    2013-11-01

    India, being a developing nation is experiencing major growth in its infrastructural sector. Concrete is the major component in construction. The requirement of good quality of concrete in large quantities can be fulfilled by ready mix concrete batching and mixing plants. The paper presents a technique of applying the value engineering tool life cycle cost analysis to a ready mix concrete plant. This will help an investor or an organization to take investment decisions regarding a ready mix concrete facility. No economic alternatives are compared in this study. A cost breakdown structure is prepared for the ready mix concrete plant. A market survey has been conducted to collect realistic costs for the ready mix concrete facility. The study establishes the cash flow for the ready mix concrete facility helpful in investment and capital generation related decisions. Transit mixers form an important component of the facility and are included in the calculations. A fleet size for transit mixers has been assumed for this purpose. The life cycle cost has been calculated for the system of the ready mix concrete plant and transit mixers.

  15. Catalytic combustion of benzene over CuO-CeO2 mixed oxides.

    PubMed

    Jung, Won Young; Lim, Kwon-Taek; Hong, Seong-Soo

    2014-11-01

    Catalytic combustion of benzene over CuO-CeO2 mixed oxides has been investigated. The CuO-CeO2 mixed oxides were prepared by the combustion method using malic acid as an organic fuel and characterized by XRD, XPS and TPR. For the CuO-CeO2 catalyst with a Cu/(Cu + Ce) molar ratio of more than 0.4, highly dispersed copper oxide species were shown at 2θ = 35.5 degrees and 38.8 degrees. The CuO-CeO2 catalyst prepared using 2.0 M malic acid showed the highest activity, with conversion reaching nearly 100% at 350 degrees C. In addition, the highest activity is shown on Cu0.40 (the index denotes the molar ratio Cu/(Cu + Ce)) sample and then it decreases on Cu0.5 and Cu0.7 samples. PMID:25958554

  16. Reforming of fuel inside fuel cell generator

    DOEpatents

    Grimble, Ralph E.

    1988-01-01

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

  17. Reforming of fuel inside fuel cell generator

    DOEpatents

    Grimble, R.E.

    1988-03-08

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

  18. Fuel and oxidizer valve assembly employs single solenoid actuator

    NASA Technical Reports Server (NTRS)

    1966-01-01

    Valve assembly simultaneously starts or stops the flow of oxidizer and fuel from separate inlet channels to reaction control motors. The assembly combines an oxidizer shutoff valve and a fuel shutoff valve which are mechanically linked and operated by a single high-speed solenoid actuator.

  19. High power density solid oxide fuel cells

    DOEpatents

    Pham, Ai Quoc; Glass, Robert S.

    2004-10-12

    A method for producing ultra-high power density solid oxide fuel cells (SOFCs). The method involves the formation of a multilayer structure cells wherein a buffer layer of doped-ceria is deposited intermediate a zirconia electrolyte and a cobalt iron based electrode using a colloidal spray deposition (CSD) technique. For example, a cobalt iron based cathode composed of (La,Sr)(Co,Fe)O (LSCF) may be deposited on a zirconia electrolyte via a buffer layer of doped-ceria deposited by the CSD technique. The thus formed SOFC have a power density of 1400 mW/cm.sup.2 at 600.degree. C. and 900 mW/cm.sup.2 at 700.degree. C. which constitutes a 2-3 times increased in power density over conventionally produced SOFCs.

  20. Solid oxide fuel cell power system development

    SciTech Connect

    Kerr, Rick; Wall, Mark; Sullivan, Neal

    2015-06-26

    This report summarizes the progress made during this contractual period in achieving the goal of developing the solid oxide fuel cell (SOFC) cell and stack technology to be suitable for use in highly-efficient, economically-competitive, commercially deployed electrical power systems. Progress was made in further understanding cell and stack degradation mechanisms in order to increase stack reliability toward achieving a 4+ year lifetime, in cost reduction developments to meet the SECA stack cost target of $175/kW (in 2007 dollars), and in operating the SOFC technology in a multi-stack system in a real-world environment to understand the requirements for reliably designing and operating a large, stationary power system.

  1. Nanostructured Solid Oxide Fuel Cell Electrodes

    SciTech Connect

    Sholklapper, Tal Zvi

    2007-01-01

    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.

  2. Nanotubular array solid oxide fuel cell.

    PubMed

    Motoyama, Munekazu; Chao, Cheng-Chieh; An, Jihwan; Jung, Hee Joon; Gür, Turgut M; Prinz, Friedrich B

    2014-01-28

    This report presents a demonstration and characterization of a nanotubular array of solid oxide fuel cells (SOFCs) made of one-end-closed hollow tube Ni/yttria-stabilized zirconia/Pt membrane electrode assemblies (MEAs). The tubular MEAs are nominally ∼5 μm long and have <500 nm outside diameter with total MEA thickness of nearly 50 nm. Open circuit voltages up to 660 mV (vs air) and power densities up to 1.3 μW cm(-2) were measured at 550 °C using H2 as fuel. The paper also introduces a fabrication methodology primarily based on a template process involving atomic layer deposition and electrodeposition for building the nanotubular MEA architecture as an important step toward achieving high surface area ultrathin SOFCs operating in the intermediate to low-temperature regime. A fabricated nanotubular SOFC theoretically attains a 20-fold increase in the effective surface, while projections indicate the possibility of achieving up to 40-fold. PMID:24266776

  3. SOLID STATE ENERGY CONVERSION ALLIANCE DELPHI SOLID OXIDE FUEL CELL

    SciTech Connect

    Steven Shaffer; Sean Kelly; Subhasish Mukerjee; David Schumann; Gail Geiger; Kevin Keegan; Larry Chick

    2004-05-07

    The objective of this project is to develop a 5 kW Solid Oxide Fuel Cell power system for a range of fuels and applications. During Phase I, the following will be accomplished: Develop and demonstrate technology transfer efforts on a 5 kW stationary distributed power generation system that incorporates steam reforming of natural gas with the option of piped-in water (Demonstration System A). Initiate development of a 5 kW system for later mass-market automotive auxiliary power unit application, which will incorporate Catalytic Partial Oxidation (CPO) reforming of gasoline, with anode exhaust gas injected into an ultra-lean burn internal combustion engine. This technical progress report covers work performed by Delphi from July 1, 2003 to December 31, 2003, under Department of Energy Cooperative Agreement DE-FC-02NT41246. This report highlights technical results of the work performed under the following tasks: Task 1 System Design and Integration; Task 2 Solid Oxide Fuel Cell Stack Developments; Task 3 Reformer Developments; Task 4 Development of Balance of Plant (BOP) Components; Task 5 Manufacturing Development (Privately Funded); Task 6 System Fabrication; Task 7 System Testing; Task 8 Program Management; Task 9 Stack Testing with Coal-Based Reformate; and Task 10 Technology Transfer from SECA CORE Technology Program. In this reporting period, unless otherwise noted Task 6--System Fabrication and Task 7--System Testing will be reported within Task 1 System Design and Integration. Task 8--Program Management, Task 9--Stack Testing with Coal Based Reformate, and Task 10--Technology Transfer from SECA CORE Technology Program will be reported on in the Executive Summary section of this report.

  4. DEVELOPMENT OF ELECTROCHEMICAL REDUCTION TECHNOLOGY FOR SPENT OXIDE FUELS

    SciTech Connect

    Hur, Jin-Mok; Seo, Chung-Seok; Kim, Ik-Soo; Hong, Sun-Seok; Kang, Dae-Seung; Park, Seong-Won

    2003-02-27

    The Advanced Spent Fuel Conditioning Process (ACP) has been under development at Korea Atomic Energy Research Institute (KAERI) since 1997. The concept is to convert spent oxide fuel into metallic form and to remove high heat-load fission products such as Cs and Sr from the spent fuel. The heat power, volume, and radioactivity of spent fuel can decrease by a factor of a quarter via this process. For the realization of ACP, a concept of electrochemical reduction of spent oxide fuel in Li2O-LiCl molten salt was proposed and several cold tests using fresh uranium oxides have been carried out. In this new electrochemical reduction process, electrolysis of Li2O and reduction of uranium oxide are taking place simultaneously at the cathode part of electrolysis cell. The conversion of uranium oxide to uranium metal can reach more than 99% ensuring the feasibility of this process.

  5. New processing methods to produce silicon carbide and beryllium oxide inert matrix and enhanced thermal conductivity oxide fuels

    NASA Astrophysics Data System (ADS)

    Sarma, K. H.; Fourcade, J.; Lee, S.-G.; Solomon, A. A.

    2006-06-01

    For inert matrix fuels, SiC and BeO represent two possible matrix phase compounds that exhibit very high thermal conductivity, high melting points, low neutron absorption, and reasonably high radiation stability. BeO is chemically compatible with UO2, PuO2 and Zircaloy to very high temperatures, but SiC reacts with all three at somewhat lower temperatures. We have developed the Polymer Impregnation and Pyrolysis or PIP method, making use of a commercial SiC polymeric precursor, to consolidate both particulate fuels like 'TRISO' microsphere fuels, and to impregnate UO2 fuels with pure stoichiometric SiC to improve their thermal conductivity. This method was employed to fabricate Enhanced Conductivity Oxide fuels, or ECO fuels with 5-10 vol.% of the high conductivity phase, and with 50 vol.% for TRISO dispersion fuels. For ECO fuels, a new 'slug/bisque' method of fabricating the UO2 fuel granules was necessary to produce sintered fuel with open pore structures, allowing almost complete impregnation of the continuous SiC phase. The advantages of the PIP process are that it is a non-damaging consolidation process for particulates (TRU, UC or TRISO microspheres), forms a continuous, pure β-SiC phase at temperatures as low as 1573 K, and allows the maximum in fissile atom density. However, several PIP impregnation cycles and high crystallization temperatures are necessary to obtain high thermal conductivity SiC. For producing IMF fuels using the PIP process, the fissile PuC and/or TRU actinides can be added in small concentrations along with SiC 'filler particles' and consolidated with the SiC precursor for either open or closed fuel cycles. For BeO, a second approach was developed for ECO fuels that involves a 'co-sintering' route to produce high density fuels with a continuous BeO phase of 5-10 vol.%. Special granulation and mixing techniques were developed, but only one normal sintering cycle is required. For BeO matrix IMF fuels, PuO2 granules and TRU actinides or

  6. Composite mixed oxide ionic and electronic conductors for hydrogen separation

    DOEpatents

    Gopalan, Srikanth; Pal, Uday B.; Karthikeyan, Annamalai; Hengdong, Cui

    2009-09-15

    A mixed ionic and electronic conducting membrane includes a two-phase solid state ceramic composite, wherein the first phase comprises an oxygen ion conductor and the second phase comprises an n-type electronically conductive oxide, wherein the electronically conductive oxide is stable at an oxygen partial pressure as low as 10.sup.-20 atm and has an electronic conductivity of at least 1 S/cm. A hydrogen separation system and related methods using the mixed ionic and electronic conducting membrane are described.

  7. Synthesis and Characterization of Mixed Metal Oxide Nanocomposite Energetic Materials

    SciTech Connect

    Gash, A; Pantoya, M; Jr., J S; Zhao, L; Shea, K; Simpson, R; Clapsaddle, B

    2003-11-18

    In the field of composite energetic materials, properties such as ingredient distribution, particle size, and morphology, affect both sensitivity and performance. Since the reaction kinetics of composite energetic materials are typically controlled by the mass transport rates between reactants, one would anticipate new and potentially exceptional performance from energetic nanocomposites. We have developed a new method of making nanostructured energetic materials, specifically explosives, propellants, and pyrotechnics, using sol-gel chemistry. A novel sol-gel approach has proven successful in preparing metal oxide/silicon oxide nanocomposites in which the metal oxide is the major component. Two of the metal oxides are tungsten trioxide and iron(III) oxide, both of which are of interest in the field of energetic materials. Furthermore, due to the large availability of organically functionalized silanes, the silicon oxide phase can be used as a unique way of introducing organic additives into the bulk metal oxide materials. As a result, the desired organic functionality is well dispersed throughout the composite material on the nanoscale. By introducing a fuel metal into the metal oxide/silicon oxide matrix, energetic materials based on thermite reactions can be fabricated. The resulting nanoscale distribution of all the ingredients displays energetic properties not seen in its microscale counterparts due to the expected increase of mass transport rates between the reactants. The synthesis and characterization of these metal oxide/silicon oxide nanocomposites and their performance as energetic materials will be discussed.

  8. Direct oxidation of waste vegetable oil in solid-oxide fuel cells

    NASA Astrophysics Data System (ADS)

    Zhou, Z. F.; Kumar, R.; Thakur, S. T.; Rudnick, L. R.; Schobert, H.; Lvov, S. N.

    Solid-oxide fuel cells with ceria, ceria-Cu, and ceria-Rh anode were demonstrated to generate stable electric power with waste vegetable oil through direct oxidation of the fuel. The only pre-treatment to the fuel was a filtration to remove particulates. The performance of the fuel cell was stable over 100 h for the waste vegetable oil without dilution. The generated power was up to 0.25 W cm -2 for ceria-Rh fuel cell. This compares favorably with previously studied hydrocarbon fuels including jet fuels and Pennsylvania crude oil.

  9. A mixed-reactants solid-polymer-electrolyte direct methanol fuel cell

    NASA Astrophysics Data System (ADS)

    Scott, K.; Shukla, A. K.; Jackson, C. L.; Meuleman, W. R. A.

    Mixed-reactants solid-polymer-electrolyte direct methanol fuel cells (SPE-DMFCs) with a PtRu/C anode and a methanol-tolerant oxygen-reduction cathode catalyst have been assembled and have been subjected to galvanostatic polarisation studies. The oxygen-reduction cathode was either of the FeTMPP/C, CoTMPP/C, FeCoTMPP/C and RuSe/C. It was found that the SPE-DMFC with the RuSe/C cathode yielded the best performance. It has been possible to achieve power densities of approximately 50 and 20 mW/cm 2 while operating a mixed-reactants SPE-DMFC at 90 °C with oxygen and air fed cathodes, respectively. Interestingly, these SPE-DMFCs exhibit no parasitic oxidation of methanol with oxygen.

  10. Coupling the Mixed Potential and Radiolysis Models for Used Fuel Degradation

    SciTech Connect

    Buck, Edgar C.; Jerden, James L.; Ebert, William L.; Wittman, Richard S.

    2013-08-30

    The primary purpose of this report is to describe the strategy for coupling three process level models to produce an integrated Used Fuel Degradation Model (FDM). The FDM, which is based on fundamental chemical and physical principals, provides direct calculation of radionuclide source terms for use in repository performance assessments. The G-value for H2O2 production (Gcond) to be used in the Mixed Potential Model (MPM) (H2O2 is the only radiolytic product presently included but others will be added as appropriate) needs to account for intermediate spur reactions. The effects of these intermediate reactions on [H2O2] are accounted for in the Radiolysis Model (RM). This report details methods for applying RM calculations that encompass the effects of these fast interactions on [H2O2] as the solution composition evolves during successive MPM iterations and then represent the steady-state [H2O2] in terms of an “effective instantaneous or conditional” generation value (Gcond). It is anticipated that the value of Gcond will change slowly as the reaction progresses through several iterations of the MPM as changes in the nature of fuel surface occur. The Gcond values will be calculated with the RM either after several iterations or when concentrations of key reactants reach threshold values determined from previous sensitivity runs. Sensitivity runs with RM indicate significant changes in G-value can occur over narrow composition ranges. The objective of the mixed potential model (MPM) is to calculate the used fuel degradation rates for a wide range of disposal environments to provide the source term radionuclide release rates for generic repository concepts. The fuel degradation rate is calculated for chemical and oxidative dissolution mechanisms using mixed potential theory to account for all relevant redox reactions at the fuel surface, including those involving oxidants produced by solution radiolysis and provided by the radiolysis model (RM). The RM calculates

  11. Effect of fuel/air nonuniformity on nitric oxide emissions

    NASA Technical Reports Server (NTRS)

    Lyons, V. J.

    1979-01-01

    A flame tube combustor holding jet A fuel was used in experiments performed at a pressure of .3 Mpa and a reference velocity of 25 meters/second for three inlet air temperatures of 600, 700, and 800 K. The gas sample measurements were taken at locations 18 cm and 48 cm downstream of the perforated plate flameholder. Nonuniform fuel/air profiles were produced using a fuel injector by separately fueling the inner five fuel tubes and the outer ring of twelve fuel tubes. Six fuel/air profiles were produced for nominal overall equivalence ratios of .5 and .6. An example of three of three of these profiles and their resultant nitric oxide NOx emissions are presented. The uniform fuel/air profile cases produced uniform and relatively low profile levels. When the profiles were either center-peaked or edge-peaked, the overall mass-weighted nitric oxide levels increased.

  12. Effects of Passive Fuel-Air Mixing Control on Burner Emissions Via Lobed Fuel Injectors

    NASA Technical Reports Server (NTRS)

    Mitchell, M. G.; Smith, O. I.; Karagozian, A. R.

    1999-01-01

    The present experimental study examines the effects of differing levels of passive fuel-air premixing on flame structures and their associated NO(x) and CO emissions. Four alternative fuel injector geometries were explored, three of which have lobed shapes. These lobed injectors mix fuel and air and strain species inter-faces to differing extents due to streamwise vorticity generation, thus creating different local or core equivalence ratios within flow regions upstream of flame ignition and stabilization. Prior experimental studies of two of these lobed injector flowfields focused on non-reactive mixing characteristics and emissions measurements for the case where air speeds were matched above and below the fuel injector, effectively generating stronger streamwise vorticity than spanwise vorticity. The present studies examine the effects of airstream mismatch (and hence additional spanwise vorticity generation), effects of confinement of the crossflow to reduce the local equivalence ratio, and the effects of altering the geometry and position of the flameholders. NO(x) and CO emissions as well as planar laser-induced fluorescence imaging (PLIF) of seeded acetone are used to characterize injector performance and reactive flow evolution.

  13. The burnup dependence of light water reactor spent fuel oxidation

    SciTech Connect

    Hanson, B.D.

    1998-07-01

    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

  14. A novel thin film solid oxide fuel cell for microscale energy conversion

    SciTech Connect

    Jankowiski, A F; Morse, J D

    1999-05-01

    A novel approach for the fabrication and assembly of a solid oxide fuel cell system is described which enables effective scaling of the fuel delivery, mainfold, and fuel cell stack components for applications in miniature and microscale energy conversion. Electrode materials for solid oxide fuel cells are developed using sputter deposition techniques. A thin film anode is formed by codeposition of nickel and yttria-stabilized zirconia (YSZ). This approach provides a mixed conducting interfacial layer between the nickel electrode and electrolyte layer. Similarly, a thin film cathode is formed by co-deposition of silver and yttria-stabilized zirconia. Additionally, sputter deposition of yttria-stabilized zirconia thin film electrolyte enables high quality, continuous films to be formed having thickness on the order of 1-2 {micro}m. This will effectively lower the temperature of operation for the fuel cell stack significantly below the traditional ranges at which solid oxide electrolyte systems are operated (600--1000 C), thereby rendering this fuel cell system suitable for miniaturization. Scaling towards miniaturization is accomplished by utilizing novel micromaching approaches which allow manifold channels and fuel delivery system to be formed within the substrate which the thin film fuel cell stack is fabricated on, thereby circumventing the need for bulky manifold components which are not directly scalable.

  15. Partial oxidation power plant with reheating and method thereof

    DOEpatents

    Newby, Richard A.; Yang, Wen-Ching; Bannister, Ronald L.

    1999-01-01

    A system and method for generating power having an air compression/partial oxidation system, a turbine, and a primary combustion system. The air compression/partial oxidation system receives a first air stream and a fuel stream and produces a first partially oxidized fuel stream and a first compressed air stream therefrom. The turbine expands the first partially oxidized fuel stream while being cooled by the first compressed air stream to produce a heated air stream. The heated air stream is injected into the expanding first partially oxidized fuel stream, thereby reheating it in the turbine. A second partially oxidized fuel stream is emitted from the turbine. The primary combustion system receives said second partially oxidized fuel stream and a second air stream, combusts said second partially oxidized fuel stream, and produces rotating shaft power and an emission stream therefrom.

  16. Partial oxidation power plant with reheating and method thereof

    DOEpatents

    Newby, R.A.; Yang, W.C.; Bannister, R.L.

    1999-08-10

    A system and method are disclosed for generating power having an air compression/partial oxidation system, a turbine, and a primary combustion system. The air compression/partial oxidation system receives a first air stream and a fuel stream and produces a first partially oxidized fuel stream and a first compressed air stream therefrom. The turbine expands the first partially oxidized fuel stream while being cooled by the first compressed air stream to produce a heated air stream. The heated air stream is injected into the expanding first partially oxidized fuel stream, thereby reheating it in the turbine. A second partially oxidized fuel stream is emitted from the turbine. The primary combustion system receives said second partially oxidized fuel stream and a second air stream, combusts said second partially oxidized fuel stream, and produces rotating shaft power and an emission stream therefrom. 2 figs.

  17. Mixed mode fuel injector with individually moveable needle valve members

    DOEpatents

    Stewart, Chris; Chockley, Scott A.; Ibrahim, Daniel R.; Lawrence, Keith; Tomaseki, Jay; Azam, Junru H.; Tian, Steven Ye; Shafer, Scott F.

    2004-08-03

    A fuel injector includes a homogenous charge nozzle outlet set and a conventional nozzle outlet set controlled respectively, by first and second needle valve members. One of the needle valve members moves to an open position while the other needle valve member remains stationary for a homogeneous charge injection event. The former needle valve member stays stationary while the other needle valve member moves to an open position for a conventional injection event. One of the needle valve members is at least partially positioned in the other needle valve member. Thus, the injector can perform homogeneous charge injection events, conventional injection events, or even a mixed mode having both types of injection events in a single engine cycle.

  18. 21. Power plant engine fuel oil piping diagrams, sheet 83 ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    21. Power plant engine fuel oil piping diagrams, sheet 83 of 130 - Naval Air Station Fallon, Power Plant, 800 Complex, off Carson Road near intersection of Pasture & Berney Roads, Fallon, Churchill County, NV

  19. Remote fabrication and irradiation test of recycled nuclear fuel prepared by the oxidation and reduction of spent oxide fuel

    NASA Astrophysics Data System (ADS)

    Jin Ryu, Ho; Chan Song, Kee; Il Park, Geun; Won Lee, Jung; Seung Yang, Myung

    2005-02-01

    A direct dry recycling process was developed in order to reuse spent pressurized light water reactor (LWR) nuclear fuel in CANDU reactors without the separation of sensitive nuclear materials such as plutonium. The benefits of the dry recycling process are the saving of uranium resources and the reduction of spent fuel accumulation as well as a higher proliferation resistance. In the process of direct dry recycling, fuel pellets separated from spent LWR fuel rods are oxidized from UO2 to U3O8 at 500 °C in an air atmosphere and reduced into UO2 at 700 °C in a hydrogen atmosphere, which is called OREOX (oxidation and reduction of oxide fuel). The pellets are pulverized during the oxidation and reduction processes due to the phase transformation between cubic UO2 and orthorhombic U3O8. Using the oxide powder prepared from the OREOX process, the compaction and sintering processes are performed in a remote manner in a shielded hot cell due to the high radioactivity of the spent fuel. Most of the fission gas and volatile fission products are removed during the OREOX and sintering processes. The mini-elements fabricated by the direct dry recycling process are irradiated in the HANARO research reactor for the performance evaluation of the recycled fuel pellets. Post-irradiation examination of the irradiated fuel showed that microstructural evolution and fission gas release behavior of the dry-recycled fuel were similar to high burnup UO2 fuel.

  20. A fuel cell balance of plant test facility

    NASA Astrophysics Data System (ADS)

    Dicks, A. L.; Martin, P. A.

    Much attention is focused in the fuel cell community on the development of reliable stack technology, but to successfully exploit fuel cells, they must form part of integrated power generation systems. No universal test facilities exist to evaluate SOFC stacks and comparatively little research has been undertaken concerning the issues of the rest of the system, or balance of plant (BOP). BG, in collaboration with Eniricerche, has therefore recently designed and built a test facility to evaluate different configurations of the BOP equipment for a 1-5 kWe solid oxide fuel cell (SOFC) stack. Within this BOP project, integrated, dynamic models have been developed. These have shown that three characteristic response times exist when the stack load is changed and that three independent control loops are required to manage the almost instantaneous change in power output from an SOFC stack, maintain the fuel utilisation and control the stack temperature. Control strategies and plant simplifications, arising from the dynamic modelling, have also been implemented in the BOP test facility. An SOFC simulator was designed and integrated into the control system of the test rig to behave as a real SOFC stack, allowing the development of control strategies without the need for a real stack. A novel combustor has been specifically designed, built and demonstrated to be capable of burning the low calorific anode exhaust gas from an SOFC using the oxygen depleted cathode stream. High temperature, low cost, shell and tube heat exchangers have been shown to be suitable for SOFC systems. Sealing of high temperature anode recirculation fans has, however, been shown to be a major issue and identified as a key area for further investigation.

  1. Equipment specifications for an electrochemical fuel reprocessing plant

    SciTech Connect

    Hemphill, Kevin P

    2010-01-01

    Electrochemical reprocessing is a technique used to chemically separate and dissolve the components of spent nuclear fuel, in order to produce new metal fuel. There are several different variations to electrochemical reprocessing. These variations are accounted for by both the production of different types of spent nuclear fuel, as well as different states and organizations doing research in the field. For this electrochemical reprocessing plant, the spent fuel will be in the metallurgical form, a product of fast breeder reactors, which are used in many nuclear power plants. The equipment line for this process is divided into two main categories, the fuel refining equipment and the fuel fabrication equipment. The fuel refining equipment is responsible for separating out the plutonium and uranium together, while getting rid of the minor transuranic elements and fission products. The fuel fabrication equipment will then convert this plutonium and uranium mixture into readily usable metal fuel.

  2. Solid oxide fuel cell operable over wide temperature range

    DOEpatents

    Baozhen, Li; Ruka, Roswell J.; Singhal, Subhash C.

    2001-01-01

    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.

  3. Oxidation and formation of deposit precursors in hydrocarbon fuels

    NASA Technical Reports Server (NTRS)

    Buttrill, S. E., Jr.; Mayo, F. R.; Lan, B.; St.john, G. A.; Dulin, D.

    1982-01-01

    A practical fuel, home heating oil no. 2 (Fuel C), and the pure hydrocarbon, n-dodecane, were subjected to mild oxidation at 130 C and the resulting oxygenated reaction products, deposit precursors, were analyzed using field ionization mass spectrometry. Results for fuel C indicated that, as oxidation was initially extended, certain oxygenated reaction products of increasing molecular weights in the form of monomers, dimers and some trimers were produced. Further oxidation time increase resulted in further increase in monomers but a marked decrease in dimers and trimers. This suggests that these larger molecular weight products have proceeded to form deposit and separated from the fuel mixture. Results for a dodecane indicated that yields for dimers and trimers were very low. Dimers were produced as a result of interaction between oxygenated products with each other rather than with another fuel molecule. This occurred even though fuel molecule concentration was 50 times, or more greater than that for these oxygenated reaction products.

  4. Electrode electrolyte interlayers containing cerium oxide for electrochemical fuel cells

    DOEpatents

    Borglum, Brian P.; Bessette, Norman F.

    2000-01-01

    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).

  5. Mixed lanthanide oxide nanoparticles as dual imaging agent in biomedicine

    NASA Astrophysics Data System (ADS)

    Xu, Wenlong; Bony, Badrul Alam; Kim, Cho Rong; Baeck, Jong Su; Chang, Yongmin; Bae, Ji Eun; Chae, Kwon Seok; Kim, Tae Jeong; Lee, Gang Ho

    2013-11-01

    There is no doubt that the molecular imaging is an extremely important technique in diagnosing diseases. Dual imaging is emerging as a step forward in molecular imaging technique because it can provide us with more information useful for diagnosing diseases than single imaging. Therefore, diverse dual imaging modalities should be developed. Molecular imaging generally relies on imaging agents. Mixed lanthanide oxide nanoparticles could be valuable materials for dual magnetic resonance imaging (MRI)-fluorescent imaging (FI) because they have both excellent and diverse magnetic and fluorescent properties useful for dual MRI-FI, depending on lanthanide ions used. Since they are mixed nanoparticles, they are compact, robust, and stable, which is extremely useful for biomedical applications. They can be also easily synthesized with facile composition control. In this study, we explored three systems of ultrasmall mixed lanthanide (Dy/Eu, Ho/Eu, and Ho/Tb) oxide nanoparticles to demonstrate their usefulness as dual T2 MRI-FI agents.

  6. Fine grain separation for the production of biomass fuel from mixed municipal solid waste.

    PubMed

    Giani, H; Borchers, B; Kaufeld, S; Feil, A; Pretz, T

    2016-01-01

    The main goal of the project MARSS (Material Advanced Sustainable Systems) is to build a demonstration plant in order to recover a renewable biomass fuel suitable for the use in biomass power plants out of mixed municipal solid waste (MMSW). The demonstration plant was constructed in Mertesdorf (Germany), working alongside an existing mechanical-biological treatment plant, where the MMSW is biological dried under aerobe conditions in rotting boxes. The focus of the presented sorting campaign was set on the processing of fine grain particles minor than 11.5mm which have the highest mass content and biogenic energy potential of the utilized grain size fractions. The objective was to produce a biomass fuel with a high calorific value and a low content of fossil (plastic, synthetic) materials while maximizing the mass recovery. Therefore, the biogenic components of the dried MMSW are separated from inert and fossil components through various classification and sifting processes. In three experimental process setups of different processing depths, the grain size fraction 4-11.5mm was sifted by the use of air sifters and air tables.

  7. Fine grain separation for the production of biomass fuel from mixed municipal solid waste.

    PubMed

    Giani, H; Borchers, B; Kaufeld, S; Feil, A; Pretz, T

    2016-01-01

    The main goal of the project MARSS (Material Advanced Sustainable Systems) is to build a demonstration plant in order to recover a renewable biomass fuel suitable for the use in biomass power plants out of mixed municipal solid waste (MMSW). The demonstration plant was constructed in Mertesdorf (Germany), working alongside an existing mechanical-biological treatment plant, where the MMSW is biological dried under aerobe conditions in rotting boxes. The focus of the presented sorting campaign was set on the processing of fine grain particles minor than 11.5mm which have the highest mass content and biogenic energy potential of the utilized grain size fractions. The objective was to produce a biomass fuel with a high calorific value and a low content of fossil (plastic, synthetic) materials while maximizing the mass recovery. Therefore, the biogenic components of the dried MMSW are separated from inert and fossil components through various classification and sifting processes. In three experimental process setups of different processing depths, the grain size fraction 4-11.5mm was sifted by the use of air sifters and air tables. PMID:26272710

  8. The quantification of mixture stoichiometry when fuel molecules contain oxidizer elements or oxidizer molecules contain fuel elements.

    SciTech Connect

    Mueller, Charles J.

    2005-05-01

    The accurate quantification and control of mixture stoichiometry is critical in many applications using new combustion strategies and fuels (e.g., homogeneous charge compression ignition, gasoline direct injection, and oxygenated fuels). The parameter typically used to quantify mixture stoichiometry (i.e., the proximity of a reactant mixture to its stoichiometric condition) is the equivalence ratio, /gf. The traditional definition of /gf is based on the relative amounts of fuel and oxidizer molecules in a mixture. This definition provides an accurate measure of mixture stoichiometry when the fuel molecule does not contain oxidizer elements and when the oxidizer molecule does not contain fuel elements. However, the traditional definition of /gf leads to problems when the fuel molecule contains an oxidizer element, as is the case when an oxygenated fuel is used, or once reactions have started and the fuel has begun to oxidize. The problems arise because an oxidizer element in a fuel molecule is counted as part of the fuel, even though it acts as an oxidizer. Similarly, if an oxidizer molecule contains fuel elements, the fuel elements in the oxidizer molecule are misleadingly lumped in with the oxidizer in the traditional definition of /gf. In either case, use of the traditional definition of /gf to quantify the mixture stoichiometry can lead to significant errors. This paper introduces the oxygen equivalence ratio, /gf/gV, a parameter that properly characterizes the instantaneous mixture stoichiometry for a broader class of reactant mixtures than does /gf. Because it is an instantaneous measure of mixture stoichiometry,/gf/gV can be used to track the time-evolution of stoichiometry as a reaction progresses. The relationship between /gf/gV and /gf is shown. Errors are involved when the traditional definition of /gf is used as a measure of mixture stoichiometry with fuels that contain oxidizer elements or oxidizers that contain fuel elements; /gf/gV is used to quantify

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

    DOEpatents

    Ruka, Roswell J.; Vora, Shailesh D.

    2001-01-01

    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.

  10. Recovery Act. Solid Oxide Fuel Cell Diesel Auxilliary Power Unit Demonstration

    SciTech Connect

    Geiger, Gail E.

    2013-09-30

    Solid Oxide Fuel Cell Diesel Auxilliary Power Unit Demonstration Project. Summarizing development of Delphi’s next generation SOFC system as the core power plant to prove the viability of the market opportunity for a 3-5 kW diesel SOFC system. Report includes test and demonstration results from testing the diesel APU in a high visibility fleet customer vehicle application.

  11. Decontamination and decommissioning of the Kerr-McGee Cimarron Plutonium Fuel Plant

    SciTech Connect

    Not Available

    1994-05-01

    This final report is a summary of the events that completes the decontamination and decommissioning of the Cimarron Corporation`s Mixed Oxides Fuel Plant (formally Sequoyah Fuels Corporation and formerly Kerr-McGee Nuclear Corporation - all three wholly owned subsidiaries of the Kerr-McGee Corporation). Included are details dealing with tooling and procedures for performing the unique tasks of disassembly decontamination and/or disposal. That material which could not be economically decontaminated was volume reduced by disassembly and/or compacted for disposal. The contaminated waste cleaning solutions were processed through filtration and ion exchange for release or solidified with cement for L.S.A. waste disposal. The L.S.A. waste was compacted, and stabilized as required in drums for burial in an approved burial facility. T.R.U. waste packaging and shipping was completed by the end of July 1987. This material was shipped to the Hanford, Washington site for disposal. The personnel protection and monitoring measures and procedures are discussed along with the results of exposure data of operating personnel. The shipping containers for both T.R.U. and L.S.A. waste are described. The results of the decommissioning operations are reported in six reports. The personnel protection and monitoring measures and procedures are contained and discussed along with the results of exposure data of operating personnel in this final report.

  12. Photochemical oxidation: A solution for the mixed waste dilemma

    SciTech Connect

    Prellberg, J.W.; Thornton, L.M.; Cheuvront, D.A.

    1995-12-31

    Numerous technologies are available to remove organic contamination from water or wastewater. A variety of techniques also exist that are used to neutralize radioactive waste. However, few technologies can satisfactorily address the treatment of mixed organic/radioactive waste without creating unacceptable secondary waste products or resulting in extremely high treatment costs. An innovative solution to the mixed waste problem is on-site photochemical oxidation. Liquid-phase photochemical oxidation has a long- standing history of successful application to the destruction of organic compounds. By using photochemical oxidation, the organic contaminants are destroyed on-site leaving the water, with radionuclides, that can be reused or disposed of as appropriate. This technology offers advantages that include zero air emissions, no solid or liquid waste formation, and relatively low treatment cost. Discussion of the photochemical process will be described, and several case histories from recent design testing, including cost analyses for the resulting full-scale installations, will be presented as examples.

  13. The insectivorous bat Pipistrellus nathusii uses a mixed-fuel strategy to power autumn migration.

    PubMed

    Voigt, Christian C; Sörgel, Karin; Šuba, Jurģis; Keišs, Oskars; Pētersons, Gunārs

    2012-09-22

    In contrast to birds, bats are possibly limited in their capacity to use body fat as an energy source for long migrations. Here, we studied the fuel choice of migratory Pipistrellus nathusii (approximate weight: 8 g) by analysing the stable carbon isotope ratio (δ(13)C(V-PDB)) of breath and potential energy sources. Breath δ(13)C(V-PDB) was intermediate between δ(13)C(V-PDB) of insect prey and adipocyte triacylglycerols, suggesting a mixed-fuel use of P. nathusii during autumn migration. To clarify the origin of oxidized fatty acids, we performed feeding experiments with captive P. nathusii. After an insect diet, bat breath was enriched in (13)C relative to the bulk and fat portion of insects, but not deviating from the non-fat portion of insects, suggesting that bats oxidized exogenous proteins and carbohydrates, but not exogenous fatty acids. A feeding experiment with (13)C-labelled substrates confirmed these findings. In conclusion, migratory P. nathusii oxidized dietary proteins directly from insects captured en route in combination with endogenous fatty acids from adipocytes, and replenished their body reserves by routing dietary fatty acids to their body reserves.

  14. The insectivorous bat Pipistrellus nathusii uses a mixed-fuel strategy to power autumn migration

    PubMed Central

    Voigt, Christian C.; Sörgel, Karin; Šuba, Jurģis; Keišs, Oskars; Pētersons, Gunārs

    2012-01-01

    In contrast to birds, bats are possibly limited in their capacity to use body fat as an energy source for long migrations. Here, we studied the fuel choice of migratory Pipistrellus nathusii (approximate weight: 8 g) by analysing the stable carbon isotope ratio (δ13CV-PDB) of breath and potential energy sources. Breath δ13CV-PDB was intermediate between δ13CV-PDB of insect prey and adipocyte triacylglycerols, suggesting a mixed-fuel use of P. nathusii during autumn migration. To clarify the origin of oxidized fatty acids, we performed feeding experiments with captive P. nathusii. After an insect diet, bat breath was enriched in 13C relative to the bulk and fat portion of insects, but not deviating from the non-fat portion of insects, suggesting that bats oxidized exogenous proteins and carbohydrates, but not exogenous fatty acids. A feeding experiment with 13C-labelled substrates confirmed these findings. In conclusion, migratory P. nathusii oxidized dietary proteins directly from insects captured en route in combination with endogenous fatty acids from adipocytes, and replenished their body reserves by routing dietary fatty acids to their body reserves. PMID:22719039

  15. On droplet combustion of biodiesel fuel mixed with diesel/alkanes in microgravity condition

    SciTech Connect

    Pan, Kuo-Long; Li, Je-Wei; Chen, Chien-Pei; Wang, Ching-Hua

    2009-10-15

    The burning characteristics of a biodiesel droplet mixed with diesel or alkanes such as dodecane and hexadecane were experimentally studied in a reduced-gravity environment so as to create a spherically symmetrical flame without the influence of natural convection due to buoyancy. Small droplets on the order of 500 {mu}m in diameter were initially injected via a piezoelectric technique onto the cross point intersected by two thin carbon fibers; these were prepared inside a combustion chamber that was housed in a drag shield, which was freely dropped onto a foam cushion. It was found that, for single component droplets, the tendency to form a rigid soot shell was relatively small for biodiesel fuel as compared to that exhibited by the other tested fuels. The soot created drifted away readily, showing a puffing phenomenon; this could be related to the distinct molecular structure of biodiesel leading to unique soot layers that were more vulnerable to oxidative reactivity as compared to the soot generated by diesel or alkanes. The addition of biodiesel to these more traditional fuels also presented better performance with respect to annihilating the soot shell, particularly for diesel. The burning rate generally follows that of multi-component fuels, by some means in terms of a lever rule, whereas the mixture of biodiesel and dodecane exhibits a somewhat nonlinear relation with the added fraction of dodecane. This might be related to the formation of a soot shell. (author)

  16. Stack configurations for tubular solid oxide fuel cells

    SciTech Connect

    Armstrong, Timothy R.; Trammell, Michael P.; Marasco, Joseph A.

    2010-08-31

    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.

  17. Diesel fuel containing wax oxidates to reduce particulate emissions

    SciTech Connect

    Sprague, H.G.; Sweeney, W.M.

    1980-09-16

    Addition of 0.1 to 1.5 percent by weight of wax oxidates to a diesel fuel is found to reduce the amount of soot and invisible particles produced when the fuel is used in a diesel engine. The wax oxidates act synergistically with fuel-soluble organometallic compounds such as alkyl cyclopentadienyl manganese tricarbonyl complex salts in reducing particulates. The wax oxidates used have a ratio of neutralization number to saponification number below about 0.40 and a saybolt universal viscosity at 210* F. Higher than 1600.

  18. Hydrothermal mixing: Fuel for life in the deep-sea

    NASA Astrophysics Data System (ADS)

    Hentscher, M.; Bach, W.; Amend, J.; McCollom, T.

    2009-04-01

    Deep-sea hydrothermal vent systems show a wide range of fluid compositions and temperatures. They reach from highly alkaline and reducing, like the Lost City hydrothermal field, to acidic and reducing conditions, (e. g., the Logatchev hydrothermal field) to acidic and oxidizing conditions (e. g., island arc hosted systems). These apparently hostile vent systems are generally accompanied by high microbial activity forming the base of a food-web that often includes higher organisms like mussels, snails, or shrimp. The primary production is boosted by mixing of chemically reduced hydrothermal vent fluids with ambient seawater, which generates redox disequilibria that serve as energy source for chemolithoautotrophic microbial life. We used geochemical reaction path models to compute the affinities of catabolic (energy-harvesting) and anabolic (biosynthesis) reactions along trajectories of batch mixing between vent fluids and 2 °C seawater. Geochemical data of endmember hydrothermal fluids from 12 different vent fields (Lost City, Rainbow, Logatchev, TAG, EPR 21 °N, Manus Basin, Mariana Arc, etc.) were included in this reconnaissance study of the variability in metabolic energetics in global submarine vent systems. The results show a distinction between ultramafic-hosted and basalt-hosted hydrothermal systems. The highest energy yield for chemolithotrophic catabolism in ultramafic-hosted hydrothermal systems is reached at low temperature and under slightly aerobic to aerobic conditions. The dominant reactions, for example at Rainbow or Lost City, are the oxidation of H2, Fe2+ and methane. At temperatures >60 °C, anaerobic metabolic reactions, e. g., sulphate reduction and methanogenesis, become more profitable. In contrast, basalt-hosted systems, such as TAG and 21 °N EPR uniformly indicate H2S oxidation to be the catabolically dominant reaction over the entire microbial-relevant temperature range. Affinities were calculated for the formation of individual cellular

  19. Air side contamination in Solid Oxide Fuel Cell stack testing

    NASA Astrophysics Data System (ADS)

    Schuler, J. Andreas; Gehrig, Christian; Wuillemin, Zacharie; Schuler, Albert J.; Wochele, Joerg; Ludwig, Christian; Hessler-Wyser, Aïcha; Van herle, Jan

    This work aimed to quantify air side contaminants during Solid Oxide Fuel Cell (SOFC) testing in stack configuration. Post-analyses of a long-term test have shown that performance degradation was mainly due to cathode pollutants originated upstream of the cell, therefore their source identification is crucial. The compressed air system, feeding the airflow to the cathode, was investigated by filtering and subsequent chemical analysis of the filters. Hot-air-sampling was redone in situ at the cathode air entry during a new test run to assess the contaminant concentrations in air in SOFC test conditions. In addition, the behavior of SOFC proximal system components, i.e. alloy oxidation, was characterized separately. Besides the investigation of silicon and sulfur contamination, the present work focused on chromium from high-temperature alloys used in Balance-of-Plant (BoP) components in direct contact with the airflow. Concentrations of volatile Cr-species under SOFC testing conditions were compared to Cr-accumulation on the tested cell as well as to Cr-evaporation rates from BoP alloys, which were individually characterized regarding oxidation behavior. Evaporated Cr quantities were found to saturate the air with Cr-vapors at the cathode air-inlet, as confirmed by the in-situ measurement of volatile species in the hot airflow, and correlate well to accumulated Cr in the cell after long term testing. The results of this study suggest guidelines to reduce air side contamination from exogenous sources in SOFC stacks.

  20. 27 CFR 19.902 - Waiver for alcohol fuel plants.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Waiver for alcohol fuel plants. 19.902 Section 19.902 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE....902 Waiver for alcohol fuel plants. All provisions of subparts A through X of this part and...

  1. Development of molten carbonate fuel cell power plant, volume 1

    NASA Astrophysics Data System (ADS)

    1985-03-01

    The technical results of a molten carbonate fuel cell power plant evelopment program are presented which establish the necessary technology base and demonstrate readiness to proceed with the fabrication and test of full size prototype stacks for coal fueled molten carbonate fuel cell power plants. The effort covered power plant systems studies, fuel cell component technology development, fuel cell stack design and analysis, manufacturing process definition, and an extensive experimental program. The reported results include: the definition and projected costs for a reference coal fueled power plant system based on user requirements, state-of-the-art advances in anode and electrolyte matrix technology, the detailed description of an internally manifolded stack design concept offering a number of attractive advantages, and the specification of the fabrication processes and methods necessary to produce and assemble this design. Results from the experimental program are documented.

  2. Advanced materials for solid oxide fuel cells

    SciTech Connect

    Armstrong, T.R.; Stevenson, J.

    1995-08-01

    The purpose of this research is to improve the properties of the current state-of-the-art materials used for solid oxide fuel cells (SOFCs). The objectives are to: (1) develop materials based on modifications of the state-of-the-art materials; (2) minimize or eliminate stability problems in the cathode, anode, and interconnect; (3) Electrochemically evaluate (in reproducible and controlled laboratory tests) the current state-of-the-art air electrode materials and cathode/electrolyte interfacial properties; (4) Develop accelerated electrochemical test methods to evaluate the performance of SOFCs under controlled and reproducible conditions; and (5) Develop and test materials for use in low-temperature SOFCs. The goal is to modify and improve the current state-of-the-art materials and minimize the total number of cations in each material to avoid negative effects on the materials properties. Materials to reduce potential deleterious interactions, (3) improve thermal, electrical, and electrochemical properties, (4) develop methods to synthesize both state-of-the-art and alternative materials for the simultaneous fabricatoin and consolidation in air of the interconnections and electrodes with the solid electrolyte, and (5) understand electrochemical reactions at materials interfaces and the effects of component composition and processing on those reactions.

  3. Synthesis and Characterization of Oxide Feedstock Powders for the Fuel Cycle R&D Program

    SciTech Connect

    Voit, Stewart L; Vedder, Raymond James; Johnson, Jared A

    2010-09-01

    Nuclear fuel feedstock properties, such as physical, chemical, and isotopic characteristics, have a significant impact on the fuel fabrication process and, by extension, the in-reactor fuel performance. This has been demonstrated through studies with UO{sub 2} spanning greater than 50 years. The Fuel Cycle R&D Program with The Department of Energy Office of Nuclear Energy has initiated an effort to develop a better understanding of the relationships between oxide feedstock, fresh fuel properties, and in-reactor fuel performance for advanced mixed oxide compositions. Powder conditioning studies to enable the use of less than ideal powders for ceramic fuel pellet processing are ongoing at Los Alamos National Laboratory (LANL) and an understanding of methods to increase the green density and homogeneity of pressed pellets has been gained for certain powders. Furthermore, Oak Ridge National Laboratory (ORNL) is developing methods for the co-conversion of mixed oxides along with techniques to analyze the degree of mixing. Experience with the fabrication of fuel pellets using co-synthesized multi-constituent materials is limited. In instances where atomically mixed solid solutions of two or more species are needed, traditional ceramic processing methods have been employed. Solution-based processes may be considered viable synthesis options, including co-precipitation (AUPuC), direct precipitation, direct-conversion (Modified Direct Denitration or MDD) and internal/external gelation (sol-gel). Each of these techniques has various advantages and disadvantages. The Fiscal Year 2010 feedstock development work at ORNL focused on the synthesis and characterization of one batch of UO{sub x} and one batch of U{sub 80}Ce{sub 20}O{sub x}. Oxide material synthesized at ORNL is being shipped to LANL for fuel fabrication process development studies. The feedstock preparation was performed using the MDD process which utilizes a rotary kiln to continuously thermally denitrate double

  4. Oxidation Protection of Uranium Nitride Fuel using Liquid Phase Sintering

    SciTech Connect

    Dr. Paul A. Lessing

    2012-03-01

    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.

  5. Synthesis and Characterization of Mixed Metal Oxide Nanocomposite Energetic Materials

    SciTech Connect

    Clapsaddle, B; Gash, A; Plantier, K; Pantoya, M; Jr., J S; Simpson, R

    2004-04-27

    In the field of composite energetic materials, properties such as ingredient distribution, particle size, and morphology affect both sensitivity and performance. Since the reaction kinetics of composite energetic materials are typically controlled by the mass transport rates between reactants, one would anticipate new and potentially exceptional performance from energetic nanocomposites. We have developed a new method of making nanostructured energetic materials, specifically explosives, propellants, and pyrotechnics, using sol-gel chemistry. A novel sol-gel approach has proven successful in preparing metal oxide/silicon oxide nanocomposites in which the metal oxide is the major component. By introducing a fuel metal, such as aluminum, into the metal oxide/silicon oxide matrix, energetic materials based on thermite reactions can be fabricated. Two of the metal oxides are tungsten trioxide and iron(III) oxide, both of which are of interest in the field of energetic materials. In addition, due to the large availability of organically functionalized silanes, the silicon oxide phase can be used as a unique way of introducing organic additives into the bulk metal oxide materials. These organic additives can cause the generation of gas upon ignition of the materials, therefore resulting in a composite material that can perform pressure/volume work. Furthermore, the desired organic functionality is well dispersed throughout the composite material on the nanoscale with the other components, and is therefore subject to the same increased reaction kinetics. The resulting nanoscale distribution of all the ingredients displays energetic properties not seen in its microscale counterparts due to the expected increase of mass transport rates between the reactants. The synthesis and characterization of iron(III) oxide/organosilicon oxide nanocomposites and their performance as energetic materials will be discussed.

  6. Dry low NOx combustion system with pre-mixed direct-injection secondary fuel nozzle

    DOEpatents

    Zuo, Baifang; Johnson, Thomas; Ziminsky, Willy; Khan, Abdul

    2013-12-17

    A combustion system includes a first combustion chamber and a second combustion chamber. The second combustion chamber is positioned downstream of the first combustion chamber. The combustion system also includes a pre-mixed, direct-injection secondary fuel nozzle. The pre-mixed, direct-injection secondary fuel nozzle extends through the first combustion chamber into the second combustion chamber.

  7. Dynamic Modeling in Solid-Oxide Fuel Cells Controller Design

    SciTech Connect

    Lu, Ning; Li, Qinghe; Sun, Xin; Khaleel, Mohammad A.

    2007-06-28

    In this paper, a dynamic model of the solid-oxide fuel cell (SOFC) power unit is developed for the purpose of designing a controller to regulate fuel flow rate, fuel temperature, air flow rate, and air temperature to maintain the SOFC stack temperature, fuel utilization rate, and voltage within operation limits. A lumped model is used to consider the thermal dynamics and the electro-chemial dynamics inside an SOFC power unit. The fluid dynamics at the fuel and air inlets are considered by using the in-flow ramp-rates.

  8. Lowering the temperature of solid oxide fuel cells.

    PubMed

    Wachsman, Eric D; Lee, Kang Taek

    2011-11-18

    Fuel cells are uniquely capable of overcoming combustion efficiency limitations (e.g., the Carnot cycle). However, the linking of fuel cells (an energy conversion device) and hydrogen (an energy carrier) has emphasized investment in proton-exchange membrane fuel cells as part of a larger hydrogen economy and thus relegated fuel cells to a future technology. In contrast, solid oxide fuel cells are capable of operating on conventional fuels (as well as hydrogen) today. The main issue for solid oxide fuel cells is high operating temperature (about 800°C) and the resulting materials and cost limitations and operating complexities (e.g., thermal cycling). Recent solid oxide fuel cells results have demonstrated extremely high power densities of about 2 watts per square centimeter at 650°C along with flexible fueling, thus enabling higher efficiency within the current fuel infrastructure. Newly developed, high-conductivity electrolytes and nanostructured electrode designs provide a path for further performance improvement at much lower temperatures, down to ~350°C, thus providing opportunity to transform the way we convert and store energy.

  9. Lowering the temperature of solid oxide fuel cells.

    PubMed

    Wachsman, Eric D; Lee, Kang Taek

    2011-11-18

    Fuel cells are uniquely capable of overcoming combustion efficiency limitations (e.g., the Carnot cycle). However, the linking of fuel cells (an energy conversion device) and hydrogen (an energy carrier) has emphasized investment in proton-exchange membrane fuel cells as part of a larger hydrogen economy and thus relegated fuel cells to a future technology. In contrast, solid oxide fuel cells are capable of operating on conventional fuels (as well as hydrogen) today. The main issue for solid oxide fuel cells is high operating temperature (about 800°C) and the resulting materials and cost limitations and operating complexities (e.g., thermal cycling). Recent solid oxide fuel cells results have demonstrated extremely high power densities of about 2 watts per square centimeter at 650°C along with flexible fueling, thus enabling higher efficiency within the current fuel infrastructure. Newly developed, high-conductivity electrolytes and nanostructured electrode designs provide a path for further performance improvement at much lower temperatures, down to ~350°C, thus providing opportunity to transform the way we convert and store energy. PMID:22096189

  10. Interfacial mixing during annealing of zinc oxide nanoparticle junctions

    NASA Astrophysics Data System (ADS)

    Hu, Ming; Giapis, Konstantinos P.; Poulikakos, Dimos

    2011-05-01

    The process of forming a junction between crystalline zinc oxide (ZnO) nanoparticles during pulsed thermal annealing in liquid tetradecane is studied using molecular dynamics simulation. Pairs of equal and unequal size particles are considered with emphasis on neck growth and atom mixing. The contact area and interface width of the junction are found to increase with heat pulse power albeit at different rates. The results suggest that it is possible to increase the junction area without significant mixing of atoms across the junction interface by tailoring the heat pulse power.

  11. Enhanced arsenic removal using mixed metal oxide impregnated chitosan beads.

    PubMed

    Yamani, Jamila S; Miller, Sarah M; Spaulding, Matthew L; Zimmerman, Julie B

    2012-09-15

    Mixed metal oxide impregnated chitosan beads (MICB) containing nanocrystalline Al₂O₃ and nanocrystalline TiO₂ were successfully developed. This adsorbent exploits the high capacity of Al₂O₃ for arsenate and the photocatalytic activity of TiO₂ to oxidize arsenite to arsenate, resulting in a removal capacity higher than that of either metal oxide alone. The composition of the beads was optimized for maximum arsenite removal in the presence of UV light. The mechanism of removal was investigated and a mode of action was proposed wherein TiO₂ oxidizes arsenite to arsenate which is then removed from solution by Al₂O₃. Pseudo-second order kinetics were used to validate the proposed mechanism. MICB is a more efficient and effective adsorbent for arsenic than TiO₂-impregnated chitosan beads (TICB), previously reported on, yet maintains a desirable life cycle, free of complex synthesis processes, toxic materials, and energy inputs. PMID:22743162

  12. Glass/BNNT Composite for Sealing Solid Oxide Fuel Cells

    NASA Technical Reports Server (NTRS)

    Bansal, Narottam P.; Hurst, Janet B.; Choi, Sung R.

    2007-01-01

    A material consisting of a barium calcium aluminosilicate glass reinforced with 4 weight percent of boron nitride nanotubes (BNNTs) has shown promise for use as a sealant in planar solid oxide fuel cells (SOFCs).

  13. Test plan for thermogravimetric analyses of BWR spent fuel oxidation

    SciTech Connect

    Einziger, R.E.

    1988-12-01

    Preliminary studies indicated the need for additional low-temperature spent fuel oxidation data to determine the behavior of spent fuel as a waste form for a tuffy repository. Short-term thermogravimetric analysis tests were recommended in a comprehensive technical approach as the method for providing scoping data that could be used to (1) evaluate the effects of variables such as moisture and burnup on the oxidation rate, (2) determine operative mechanisms, and (3) guide long-term, low-temperature oxidation testing. The initial test series studied the temperature and moisture effects on pressurized water reactor fuel as a function of particle and grain size. This document presents the test matrix for studying the oxidation behavior of boiling water reactor fuel in the temperature range of 140 to 225{degree}C. 17 refs., 7 figs., 3 tabs.

  14. Fuel-air mixing apparatus for reducing gas turbine combustor exhaust emissions

    NASA Technical Reports Server (NTRS)

    Zupanc, Frank J. (Inventor); Yankowich, Paul R. (Inventor)

    2006-01-01

    A fuel-air mixer for use in a combustion chamber of a gas turbine engine is provided. The fuel air mixing apparatus comprises an annular fuel injector having a plurality of discrete plain jet orifices, a first swirler wherein the first swirler is located upstream from the fuel injector and a second swirler wherein the second swirler is located downstream from the fuel injector. The plurality of discrete plain jet orifices are situated between the highly swirling airstreams generated by the two radial swirlers. The distributed injection of the fuel between two highly swirling airstreams results in rapid and effective mixing to the desired fuel-air ratio and prevents the formation of local hot spots in the combustor primary zone. A combustor and a gas turbine engine comprising the fuel-air mixer of the present invention are also provided as well as a method using the fuel-air mixer of the present invention.

  15. The impact of the initial state on the kinetics of oxidation ion- modified fuel cladding alloy E110

    NASA Astrophysics Data System (ADS)

    Kalin, B. A.; Volkov, N. V.; Valikov, R. A.; Yashin, A. S.; Yakutkina, T. V.

    2016-04-01

    The paper examines the impact of the initial state (the presence of impurities, surface preparation), and surface alloying on the kinetics of the oxidation of fuel cladding alloy E110. The studies concluded that the use of ionic polishing instead of traditional chemical polishing helps to reduce the rate of oxidation of zirconium alloys. Also studied the effect of alloying elements introduced in the surface layers of claddings by ion mixing on the kinetics of the oxidation of the alloy E110.

  16. Mechanical modeling of porous oxide fuel pellet A Test Problem

    SciTech Connect

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

    2009-10-01

    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

  17. Symmetrical, bi-electrode supported solid oxide fuel cell

    NASA Technical Reports Server (NTRS)

    Cable, Thomas L. (Inventor); Sofie, Stephen W. (Inventor)

    2009-01-01

    The present invention is a symmetrical bi-electrode supported solid oxide fuel cell comprising a sintered monolithic framework having graded pore electrode scaffolds that, upon treatment with metal solutions and heat subsequent to sintering, acquire respective anodic and cathodic catalytic activity. The invention is also a method for making such a solid oxide fuel cell. The graded pore structure of the graded pore electrode scaffolds in achieved by a novel freeze casting for YSZ tape.

  18. Design and synthesis of mixed oxides nanoparticles for biofuel applications

    SciTech Connect

    Chen, Senniang

    2010-05-15

    The work in this dissertation presents the synthesis of two mixed metal oxides for biofuel applications and NMR characterization of silica materials. In the chapter 2, high catalytic efficiency of calcium silicate is synthesized for transesterfication of soybean oil to biodisels. Chapter 3 describes the synthesis of a new Rh based catalyst on mesoporous manganese oxides. The new catalyst is found to have higher activity and selectivity towards ethanol. Chapter 4 demonstrates the applications of solid-state Si NMR in the silica materials.

  19. 11. Buttress rising above stream bed elevation. Concrete mixing plant ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    11. Buttress rising above stream bed elevation. Concrete mixing plant is at right, west tower and placement tower boom are visible. Photographer unknown, November 24, 1926. Source: Ralph Pleasant. - Waddell Dam, On Agua Fria River, 35 miles northwest of Phoenix, Phoenix, Maricopa County, AZ

  20. Finite element analysis of monolithic solid oxide fuel cells

    SciTech Connect

    Saigal, A. . Dept. of Mechanical Engineering); Majumdar, S. )

    1992-01-01

    This paper investigates the stress and fracture behavior of a monolithic solid oxide fuel cell (MSOFC) currently under joint development by Allied Signal Corporation and Argonne National Laboratory. The MSOFC is an all-ceramic fuel cell capable of high power density and tolerant of a variety of hydrocarbon fuels, making it potentially attractive for stationary utility and mobile transportation systems. The monolithic design eliminates inactive structural supports, increases active surface area, and lowers voltage losses caused by internal resistance.

  1. Finite element analysis of monolithic solid oxide fuel cells

    SciTech Connect

    Saigal, A.; Majumdar, S.

    1992-04-01

    This paper investigates the stress and fracture behavior of a monolithic solid oxide fuel cell (MSOFC) currently under joint development by Allied Signal Corporation and Argonne National Laboratory. The MSOFC is an all-ceramic fuel cell capable of high power density and tolerant of a variety of hydrocarbon fuels, making it potentially attractive for stationary utility and mobile transportation systems. The monolithic design eliminates inactive structural supports, increases active surface area, and lowers voltage losses caused by internal resistance.

  2. Fuels from renewable resources

    NASA Astrophysics Data System (ADS)

    Hoffmann, L.; Schnell, C.; Gieseler, G.

    Consideration is given to fuel substitution based on regenerative plants. Methanol can be produced from regenerative plants by gasification followed by the catalytic hydration of carbon oxides. Ethanol can be used as a replacement fuel in gasoline and diesel engines and its high-knock rating allows it to be mixed with lead-free gasoline. Due to the depletion of oil and gas reserves, fermentation alcohol is being considered. The raw materials for the fermentation process can potentially include: (1) sugar (such as yeasts, beet or cane sugar); (2) starch (from potatoes or grain) and (3) cellulose which can be hydrolized into glucose for fermentation.

  3. Coherent Anti-Stokes Raman Scattering (CARS) as a Probe for Supersonic Hydrogen-Fuel/Air Mixing

    NASA Technical Reports Server (NTRS)

    Danehy, P. M.; O'Byrne, S.; Cutler, A. D.; Rodriguez, C. G.

    2003-01-01

    The dual-pump coherent anti-Stokes Raman spectroscopy (CARS) method was used to measure temperature and the absolute mole fractions of N2, O2 and H2 in a supersonic non-reacting fuel-air mixing experiment. Experiments were conducted in NASA Langley Research Center s Direct Connect Supersonic Combustion Test Facility. Under normal operation of this facility, hydrogen and air burn to increase the enthalpy of the test gas and O2 is added to simulate air. This gas is expanded through a Mach 2 nozzle and into a combustor model where fuel is then injected, mixes and burns. In the present experiment the O2 of the test gas is replaced by N2. The lack of oxidizer inhibited combustion of the injected H2 fuel jet allowing the fuel/air mixing process to be studied. CARS measurements were performed 427 mm downstream of the nozzle exit and 260 mm downstream of the fuel injector. Maps were obtained of the mean temperature, as well as the N2, O2 and H2 mean mole fraction fields. A map of mean H2O vapor mole fraction was also inferred from these measurements. Correlations between different measured parameters and their fluctuations are presented. The CARS measurements are compared with a preliminary computational prediction of the flow.

  4. Materials for Intermediate-Temperature Solid-Oxide Fuel Cells

    NASA Astrophysics Data System (ADS)

    Kilner, John A.; Burriel, Mónica

    2014-07-01

    Solid-oxide fuel cells are devices for the efficient conversion of chemical energy to electrical energy and heat. Research efforts are currently addressed toward the optimization of cells operating at temperatures in the region of 600°C, known as intermediate-temperature solid-oxide fuel cells, for which materials requirements are very stringent. In addition to the requirements of mechanical and chemical compatibility, the materials must show a high degree of oxide ion mobility and electrochemical activity at this low temperature. Here we mainly examine the criteria for the development of two key components of intermediate-temperature solid-oxide fuel cells: the electrolyte and the cathode. We limit the discussion to novel approaches to materials optimization and focus on the fluorite oxide for electrolytes, principally those based on ceria and zirconia, and on perovskites and perovskite-related families in the case of cathodes.

  5. Geometric Frustration in the Mixed Layer Pnictide Oxides

    SciTech Connect

    Enjalran, M.; Scalettar, R.T.; Kauzlarich, S.M.

    2000-06-06

    The authors present results from a Monte Carlo investigation of a simple bilayer model with geometrically frustrated interactions similar to those found in the mixed layer pnictide oxides (Sr{sub 2}Mn{sub 3}Pn{sub 2}O{sub 2}, Pn = As, Sb). The model is composed of two inequivalent square lattices with nearest-neighbor intra- and interlayer interactions. They find a ground state composed of two independent Neel ordered layers when the interlayer exchange is an order of magnitude weaker than the intralayer exchange, as suggested by experiment. Evidence for local orthogonal order between the layers is found, but it occurs in regions of parameter space which are not experimentally realized. Qualitatively similar results were observed in models with a larger number of layers. They conclude that frustration caused by nearest-neighbor interactions in the mixed layer pnictide oxides is not sufficient to explain the long-range orthogonal order that is observed experimentally.

  6. On the actual cathode mixed potential in direct methanol fuel cells

    NASA Astrophysics Data System (ADS)

    Zago, M.; Bisello, A.; Baricci, A.; Rabissi, C.; Brightman, E.; Hinds, G.; Casalegno, A.

    2016-09-01

    Methanol crossover is one of the most critical issues hindering commercialization of direct methanol fuel cells since it leads to waste of fuel and significantly affects cathode potential, forming a so-called mixed potential. Unfortunately, due to the sluggish anode kinetics, it is not possible to obtain a reliable estimation of cathode potential by simply measuring the cell voltage. In this work we address this limitation, quantifying the mixed potential by means of innovative open circuit voltage (OCV) tests with a methanol-hydrogen mixture fed to the anode. Over a wide range of operating conditions, the resulting cathode overpotential is between 250 and 430 mV and is strongly influenced by methanol crossover. We show using combined experimental and modelling analysis of cathode impedance that the methanol oxidation at the cathode mainly follows an electrochemical pathway. Finally, reference electrode measurements at both cathode inlet and outlet provide a local measurement of cathode potential, confirming the reliability of the innovative OCV tests and permitting the evaluation of cathode potential up to typical operating current. At 0.25 A cm-2 the operating cathode potential is around 0.85 V and the Ohmic drop through the catalyst layer is almost 50 mV, which is comparable to that in the membrane.

  7. Evaluation of a 2-MW carbonate fuel cell power plant fueled by landfill gas. Final report

    SciTech Connect

    Meade, D.B.; Selander, S.; Rastler, D.M.

    1991-11-01

    This project assessed the technical and economic feasibility of operating an atmospheric pressure 2 MW carbonate fuel cell power plant on landfill gas. A commercially available low pressure gas pre-treatment system was identified for this application. System simulation studies were performed to identify component bottle-necks which would limit power production, or preclude system operation. An economic assessment was conducted to assess the competitiveness of the fuel cell system. The analysis confirmed the technical feasibility of operating Energy Research Corporation`s 2MW fuel cell system on landfill gas. Resulting net electrical efficiency was 50% based on the fuel`s lower heating value. Plant capital cost increased by {approximately}$180/kw; this was primarily for gas cleanup. Bus bar power costs for market entry and commercial fuel cell plants were found to be competitive with power produced from baseload coal plants in Minnesota.

  8. Connections for solid oxide fuel cells

    DOEpatents

    Collie, Jeffrey C.

    1999-01-01

    A connection for fuel cell assemblies is disclosed. The connection includes compliant members connected to individual fuel cells and a rigid member connected to the compliant members. Adjacent bundles or modules of fuel cells are connected together by mechanically joining their rigid members. The compliant/rigid connection permits construction of generator fuel cell stacks from basic modular groups of cells of any desired size. The connections can be made prior to installation of the fuel cells in a generator, thereby eliminating the need for in-situ completion of the connections. In addition to allowing pre-fabrication, the compliant/rigid connections also simplify removal and replacement of sections of a generator fuel cell stack.

  9. Fuel/oxidizer-rich high-pressure preburners. [staged-combustion rocket engine

    NASA Technical Reports Server (NTRS)

    Schoenman, L.

    1981-01-01

    The analyses, designs, fabrication, and cold-flow acceptance testing of LOX/RP-1 preburner components required for a high-pressure staged-combustion rocket engine are discussed. Separate designs of injectors, combustion chambers, turbine simulators, and hot-gas mixing devices are provided for fuel-rich and oxidizer-rich operation. The fuel-rich design addresses the problem of non-equilibrium LOX/RP-1 combustion. The development and use of a pseudo-kinetic combustion model for predicting operating efficiency, physical properties of the combustion products, and the potential for generating solid carbon is presented. The oxygen-rich design addresses the design criteria for the prevention of metal ignition. This is accomplished by the selection of materials and the generation of well-mixed gases. The combining of unique propellant injector element designs with secondary mixing devices is predicted to be the best approach.

  10. Progress and prospects for phosphoric acid fuel cell power plants

    SciTech Connect

    Bonville, L.J.; Scheffler, G.W.; Smith, M.J.

    1996-12-31

    International Fuel Cells (IFC) has developed the fuel cell power plant as a new, on-site power generation source. IFC`s commercial fuel cell product is the 200-kW PC25{trademark} power plant. To date over 100 PC25 units have been manufactured. Fleet operating time is in excess of one million hours. Individual units of the initial power plant model, the PC25 A, have operated for more than 30,000 hours. The first model {open_quotes}C{close_quotes} power plant has over 10,000 hours of operation. The manufacturing, application and operation of this power plant fleet has established a firm base for design and technology development in terms of a clear understanding of the requirements for power plant reliability and durability. This fleet provides the benchmark against which power plant improvements must be measured.

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

    SciTech Connect

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

    2006-07-01

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

  12. Pulse irradiation tests of rock-like oxide fuel

    NASA Astrophysics Data System (ADS)

    Okonogi, K.; Nakamura, T.; Yoshinaga, M.; Ishijima, K.; Akie, H.; Takano, H.

    1999-08-01

    Pulse irradiation tests of special oxide fuel designed for plutonium disposal, called rock-like oxide (ROX), have been conducted in the Nuclear Safety Research Reactor (NSRR) to investigate the transient behavior of ROX fuel under reactivity initiated accident (RIA) conditions. An uranium free ROX, (Zr,Y)O 2-MgAl 2O 4-PuO 2, is proposed for once-through use of Pu in light water reactors. However, because of smaller negative Doppler and void reactivity coefficients in the ROX fuel, higher peak fuel enthalpies are expected under RIAs than for UO 2 fuel. Thus, the tests of simulated ROX, in which Pu was replaced by U for easier realization, were conducted to a peak fuel enthalpy of 0.96 kJ g -1 (230 cal g -1), which is above current Japanese safety limits for UO 2. The transient behavior of the simulated ROX fuel was quite different from that of UO 2, because of its different thermo-physical properties. Fuel failure was associated with fuel melting at peak fuel enthalpies of 1.63 kJ g -1 (390 cal g -1) to 2.22 kJ g -1 (530 cal g -1). Significant mechanical energy generation, the reason for the limit, however, was not observed.

  13. Investigation into the effects of sulfur on syngas reforming inside a solid oxide fuel cell

    NASA Astrophysics Data System (ADS)

    Li, Ting Shuai; Xu, Min; Gao, Chongxin; Wang, Baoqing; Liu, Xiyun; Li, Baihai; Wang, Wei Guo

    2014-07-01

    The electrochemical performance and long-term durability of a solid oxide fuel cell have been evaluated with a simulated coal syngas containing 2 ppm H2S as fuel. The resulting impedance spectra indicate that no observable power loss is caused by the addition of 2 ppm H2S, and the cell shows stability of nearly 500 h at 0.625 A cm-2. The composition of mixed gas is analyzed both at a current load of 0.625 A cm-2 and open circuit state. Hydrogen and carbon monoxide are directly consumed as fuels at the anode side, whereas methane stays unchanged during the operation. It seems the internal carbohydrate reforming and impurity poisoning interacts and weakens the poisoning effects. The oxidation of H2 and the water gas shift reaction take advantages over methane reforming at the cell operational conditions.

  14. Flexible Electronics Powered by Mixed Metal Oxide Thin Film Transistors

    NASA Astrophysics Data System (ADS)

    Marrs, Michael

    A low temperature amorphous oxide thin film transistor (TFT) and amorphous silicon PIN diode backplane technology for large area flexible digital x-ray detectors has been developed to create 7.9-in. diagonal backplanes. The critical steps in the evolution of the backplane process include the qualification and optimization of the low temperature (200 °C) metal oxide TFT and a-Si PIN photodiode process, the stability of the devices under forward and reverse bias stress, the transfer of the process to flexible plastic substrates, and the fabrication and assembly of the flexible detectors. Mixed oxide semiconductor TFTs on flexible plastic substrates suffer from performance and stability issues related to the maximum processing temperature limitation of the polymer. A novel device architecture based upon a dual active layer improves both the performance and stability. Devices are directly fabricated below 200 ºC on a polyethylene naphthalate (PEN) substrate using mixed metal oxides of either zinc indium oxide (ZIO) or indium gallium zinc oxide (IGZO) as the active semiconductor. The dual active layer architecture allows for adjustment to the saturation mobility and threshold voltage stability without the requirement of high temperature annealing, which is not compatible with flexible plastic substrates like PEN. The device performance and stability is strongly dependent upon the composition of the mixed metal oxide; this dependency provides a simple route to improving the threshold voltage stability and drive performance. By switching from a single to a dual active layer, the saturation mobility increases from 1.2 cm2/V-s to 18.0 cm2/V-s, while the rate of the threshold voltage shift decreases by an order of magnitude. This approach could assist in enabling the production of devices on flexible substrates using amorphous oxide semiconductors. Low temperature (200°C) processed amorphous silicon photodiodes were developed successfully by balancing the tradeoffs

  15. 40 CFR 721.5315 - Nickel, cobalt mixed metal oxide (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Nickel, cobalt mixed metal oxide... Specific Chemical Substances § 721.5315 Nickel, cobalt mixed metal oxide (generic). (a) Chemical substance... nickel, cobalt mixed metal oxide. (PMN P-02-90) is subject to reporting under this section for...

  16. 40 CFR 721.5315 - Nickel, cobalt mixed metal oxide (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Nickel, cobalt mixed metal oxide... Specific Chemical Substances § 721.5315 Nickel, cobalt mixed metal oxide (generic). (a) Chemical substance... nickel, cobalt mixed metal oxide. (PMN P-02-90) is subject to reporting under this section for...

  17. 40 CFR 721.5315 - Nickel, cobalt mixed metal oxide (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Nickel, cobalt mixed metal oxide... Specific Chemical Substances § 721.5315 Nickel, cobalt mixed metal oxide (generic). (a) Chemical substance... nickel, cobalt mixed metal oxide. (PMN P-02-90) is subject to reporting under this section for...

  18. 40 CFR 721.5315 - Nickel, cobalt mixed metal oxide (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Nickel, cobalt mixed metal oxide... Specific Chemical Substances § 721.5315 Nickel, cobalt mixed metal oxide (generic). (a) Chemical substance... nickel, cobalt mixed metal oxide. (PMN P-02-90) is subject to reporting under this section for...

  19. 40 CFR 721.5315 - Nickel, cobalt mixed metal oxide (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Nickel, cobalt mixed metal oxide... Specific Chemical Substances § 721.5315 Nickel, cobalt mixed metal oxide (generic). (a) Chemical substance... nickel, cobalt mixed metal oxide. (PMN P-02-90) is subject to reporting under this section for...

  20. 40 CFR 721.10574 - Alkylcarboxy polyester acrylate reaction products with mixed metal oxides (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... reaction products with mixed metal oxides (generic). 721.10574 Section 721.10574 Protection of Environment... reaction products with mixed metal oxides (generic). (a) Chemical substance and significant new uses... reaction products with mixed metal oxides (PMN P-09-48) is subject to reporting under this section for...

  1. 40 CFR 721.10574 - Alkylcarboxy polyester acrylate reaction products with mixed metal oxides (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... reaction products with mixed metal oxides (generic). 721.10574 Section 721.10574 Protection of Environment... reaction products with mixed metal oxides (generic). (a) Chemical substance and significant new uses... reaction products with mixed metal oxides (PMN P-09-48) is subject to reporting under this section for...

  2. 40 CFR 721.10147 - Acrylate derivative of alkoxysilylalkane ester and mixed metal oxides (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... alkoxysilylalkane ester and mixed metal oxides (generic). 721.10147 Section 721.10147 Protection of Environment... alkoxysilylalkane ester and mixed metal oxides (generic). (a) Chemical substance and significant new uses subject to... ester and mixed metal oxides (PMN P-07-198) is subject to reporting under this section for...

  3. 40 CFR 721.10147 - Acrylate derivative of alkoxysilylalkane ester and mixed metal oxides (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... alkoxysilylalkane ester and mixed metal oxides (generic). 721.10147 Section 721.10147 Protection of Environment... alkoxysilylalkane ester and mixed metal oxides (generic). (a) Chemical substance and significant new uses subject to... ester and mixed metal oxides (PMN P-07-198) is subject to reporting under this section for...

  4. 40 CFR 721.10147 - Acrylate derivative of alkoxysilylalkane ester and mixed metal oxides (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... alkoxysilylalkane ester and mixed metal oxides (generic). 721.10147 Section 721.10147 Protection of Environment... alkoxysilylalkane ester and mixed metal oxides (generic). (a) Chemical substance and significant new uses subject to... ester and mixed metal oxides (PMN P-07-198) is subject to reporting under this section for...

  5. 40 CFR 721.10147 - Acrylate derivative of alkoxysilylalkane ester and mixed metal oxides (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... alkoxysilylalkane ester and mixed metal oxides (generic). 721.10147 Section 721.10147 Protection of Environment... alkoxysilylalkane ester and mixed metal oxides (generic). (a) Chemical substance and significant new uses subject to... ester and mixed metal oxides (PMN P-07-198) is subject to reporting under this section for...

  6. 40 CFR 721.10147 - Acrylate derivative of alkoxysilylalkane ester and mixed metal oxides (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... alkoxysilylalkane ester and mixed metal oxides (generic). 721.10147 Section 721.10147 Protection of Environment... alkoxysilylalkane ester and mixed metal oxides (generic). (a) Chemical substance and significant new uses subject to... ester and mixed metal oxides (PMN P-07-198) is subject to reporting under this section for...

  7. Process Developed for Fabricating Engineered Pore Structures for High- Fuel-Utilization Solid Oxide Fuel Cells

    NASA Technical Reports Server (NTRS)

    Sofie, Stephen W.; Cable, Thomas L.; Salamone, Sam M.

    2005-01-01

    Solid oxide fuel cells (SOFCs) have tremendous commercial potential because of their high efficiency, high energy density, and flexible fuel capability (ability to use fossil fuels). The drive for high-power-utilizing, ultrathin electrolytes (less than 10 microns), has placed an increased demand on the anode to provide structural support, yet allow sufficient fuel entry for sustained power generation. Concentration polarization, a condition where the fuel demand exceeds the supply, is evident in all commercial-based anode-supported cells, and it presents a significant roadblock to SOFC commercialization.

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

    SciTech Connect

    Singhal, S.C.

    1997-12-01

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

  9. Nondestructive characterization methods for monolithic solid oxide fuel cells

    SciTech Connect

    Ellingson, W.A.

    1993-01-01

    Monolithic solid oxide fuel cells (MSOFCS) represent a potential breakthrough in fuel cell technology, provided that reliable fabrication methods can be developed. Fabrication difficulties arise in several steps of the processing: First is the fabrication of uniform thin (305 {mu}m) single-layer and trilayer green tapes (the trilayer tapes of anode/electrolyte/cathode and anode/interconnect/cathode must have similar coefficients of thermal expansion to sinter uniformly and to have the necessary electrochemical properties); Second is the development of fuel and oxidant channels in which residual stresses are likely to develop in the tapes; Third is the fabrication of a ``complete`` cell for which the bond quality between layers and the quality of the trilayers must be established; and Last, attachment of fuel and oxidant manifolds and verification of seal integrity. Purpose of this report is to assess nondestructive characterization methods that could be developed for application to laboratory, prototype, and full-scale MSOFCs.

  10. Testing of fuel/oxidizer-rich, high-pressure preburners

    NASA Technical Reports Server (NTRS)

    Lawver, B. R.

    1982-01-01

    Results of an evaluation of high pressure combustion of fuel rich and oxidizer rich LOX/RP-1 propellants using 4.0 inch diameter prototype preburner injectors and chambers are presented. Testing covered a pressure range from 8.9 to 17.5 MN/square meters (1292 to 2540 psia). Fuel rich mixture ratios ranged from 0.238 to 0.367; oxidizer rich mixture ratios ranged from 27.2 to 47.5. Performance, gas temperature uniformity, and stability data for two fuel rich and two ozidizer rich preburner injectors are presented for a conventional like-on-like (LOL) design and a platelet design injector. Kinetically limited combustion is shown by the excellent agreement of measured fuel rich gas composition and C performance data with kinetic model predictions. The oxidizer rich test results support previous equilibrium combustion predictions.

  11. Bulk characterization of (U, Pu) mixed carbide fuel for distribution of plutonium

    SciTech Connect

    Devi, K. V. Vrinda Khan, K. B.; Biju, K.; Kumar, Arun

    2015-06-24

    Homogeneous distribution of plutonium in (U, Pu) mixed fuels is important from fuel performance as well as reprocessing point of view. Radiation imaging and assay techniques are employed for the detection of Pu rich agglomerates in the fuel. A simulation study of radiation transport was carried out to analyse the technique of autoradiography so as to estimate the minimum detectability of Pu agglomerates in MC fuel with nominal PuC content of 70% using Monte Carlo simulations.

  12. Fuel injection and mixing systems and methods of using the same

    DOEpatents

    Mao, Chien-Pei; Short, John

    2010-08-03

    A fuel injection and mixing system is provided. The system includes an injector body having a fuel inlet and a fuel outlet, and defines a fuel flow path between the inlet and outlet. The fuel flow path may include a generally helical flow passage having an inlet end portion disposed proximate the fuel inlet of the injector body. The flow path also may include an expansion chamber downstream from and in fluid communication with the helical flow passage, as well as a fuel delivery device in fluid communication with the expansion chamber for delivering fuel. Heating means is also provided in thermal communication with the injector body. The heating means may be adapted and configured for maintaining the injector body at a predetermined temperature to heat fuel traversing the flow path. A method of preheating and delivering fuel is also provided.

  13. Modeling of Spent Fuel Oxidation at Low Temperature

    SciTech Connect

    Poulesquen, Arnaud; Ferry, Cecile; Desgranges, Lionel

    2007-07-01

    During dry storage, the oxidation of the spent fuel in case of cladding and container failure (accidental scenario) could be detrimental for further handling of the spent fuel rod and for the safety of the facilities. Depending on whether the uranium dioxide is under the form of powder or pellet, irradiated or unirradiated, the weight gain curves do not present the same shape. To account for these different behaviours, two models have been developed. Firstly, the oxidation of unirradiated powders has been modelled based on the coexistence, during the oxidation, of two intermediate products, U{sub 4}O{sub 9} and U{sub 3}O{sub 7}. The comparison between the calculation and the literature data is good in terms of weight gain curves and chemical diffusion coefficient of oxygen within the two phases. Secondly, the oxidation of spent fuel fragments is approached by a convolution procedure between a grain oxidation model and an empirical parameter which represents the linear oxidation speed of grain boundary or an average distance able to cover the entire spent fuel fragment. This procedure of calculation allows in one hand to account for the incubation period noticed on unirradiated pellets or spent fuel and in another hand to link the empirical parameter to physical as porosity, cracks or linear power, or operational parameters such as fission gas release (FGR) respectively. A comparison of this new modelling with experimental data will be proposed. (authors)

  14. Remote-controlled NDA (nondestructive assay) systems for process areas in a MOX (mixed oxide) facility

    SciTech Connect

    Miller, M.C.; Menlove, H.O.; Augustson, R.H.; Ohtani, T.; Seya, M.; Takahashi, S.; Abedin-Zadeh, R.

    1989-01-01

    Nondestructive assay (NDA) systems have been designed and installed in the process area of an automated mixed-oxide (MOX) fuel fabrication facility. These instruments employ neutron coincidence counting methods to measure the spontaneous-fission rate of plutonium in the powders, pellets, and fuel pins in the process area. The spontaneous fission rate and the plutonium isotopic ratios determine the mass of plutonium in the sample. Measurements can be either attended or unattended. The fuel-pin assay system (FPAS) resides above the robotic conveyor system and measures the plutonium content in fuel-pin trays containing up to 24 pins (/approximately/1 kg of plutonium). The material accountancy glove-box (MAGB) counters consist of two slab detectors mounted on the sides of the glove box to measure samples of powder or pellets as they are brought to the load cell. Samples measured by the MAGB counters may contain up to 18 kg of MOX. This paper describes the design and performance of four systems: the fuel-pin assay system and three separate MAGB systems. The paper also discusses the role of Monte Carlo transport techniques in the detector design and subsequent instrument calibration. 5 refs., 11 figs., 6 tabs.

  15. Gasification Characteristics of Coal/Biomass Mixed Fuels

    SciTech Connect

    Mitchell, Reginald

    2014-09-01

    A research project was undertaken that had the overall objective of developing the models needed to accurately predict conversion rates of coal/biomass mixtures to synthesis gas under conditions relevant to a commercially-available coal gasification system configured to co-produce electric power as well as chemicals and liquid fuels. In our efforts to accomplish this goal, experiments were performed in an entrained flow reactor in order to produce coal and biomass chars at high heating rates and temperatures, typical of the heating rates and temperatures fuel particles experience in real systems. Mixed chars derived from coal/biomass mixtures containing up to 50% biomass and the chars of the pure coal and biomass components were subjected to a matrix of reactivity tests in a pressurized thermogravimetric analyzer (TGA) in order to obtain data on mass loss rates as functions of gas temperature, pressure and composition as well as to obtain information on the variations in mass specific surface area during char conversion under kinetically-limited conditions. The experimental data were used as targets when determining the unknown parameters in the chemical reactivity and specific surface area models developed. These parameters included rate coefficients for the reactions in the reaction mechanism, enthalpies of formation and absolute entropies of adsorbed species formed on the carbonaceous surfaces, and pore structure coefficients in the model used to describe how the mass specific surface area of the char varies with conversion. So that the reactivity models can be used at high temperatures when mass transport processes impact char conversion rates, Thiele modulus – effectiveness factor relations were also derived for the reaction mechanisms developed. In addition, the reactivity model and a mode of conversion model were combined in a char-particle gasification model that includes the effects of chemical reaction and diffusion of reactive gases through particle

  16. Partial oxidation fuel reforming for automotive power systems.

    SciTech Connect

    Ahmed, S.; Chalk, S.; Krumpelt, M.; Kumar, R.; Milliken, J.

    1999-09-07

    For widespread use of fuel cells to power automobiles in the near future, it is necessary to convert gasoline or other transportation fuels to hydrogen on-board the vehicle. Partial oxidation reforming is particularly suited to this application as it eliminates the need for heat exchange at high temperatures. Such reformers offer rapid start and good dynamic performance. Lowering the temperature of the partial oxidation process, which requires the development of a suitable catalyst, can increase the reforming efficiency. Catalytic partial oxidation (or autothermal) reformers and non-catalytic partial oxidation reformers developed by various organizations are presently undergoing testing and demonstration. This paper summarizes the process chemistries as well as recent test data from several different reformers operating on gasoline, methanol, and other fuels.

  17. Building dismantlement and site remediation at the Apollo Fuel Plant: When is technology the answer?

    SciTech Connect

    Walton, L.

    1995-01-01

    The Apollo fuel plant was located in Pennsylvania on a site known to have been used continuously for stell production from before the Civil War until after World War II. Then the site became a nuclear fuel chemical processing plants. Finally it was used to convert uranium hexafluoride to various oxide fuel forms. After the fuel manufacturing operations were teminated, the processing equipment was partially decontaminated, removed, packaged and shipped to a licensed low-level radioactive waste burial site. The work was completed in 1984. In 1990 a detailed site characterization was initiated to establishe the extent of contamination and to plan the building dismantlement and soil remediation efforts. This article discusses the site characterization and remedial action at the site in the following subsections: characterization; criticality control; mobile containment; soil washing; in-process measurements; and the final outcome of the project.

  18. Large Eddy Simulation of the fuel transport and mixing process in a scramjet combustor with rearwall-expansion cavity

    NASA Astrophysics Data System (ADS)

    Cai, Zun; Liu, Xiao; Gong, Cheng; Sun, Mingbo; Wang, Zhenguo; Bai, Xue-Song

    2016-09-01

    Large Eddy Simulation (LES) was employed to investigate the fuel/oxidizer mixing process in an ethylene fueled scramjet combustor with a rearwall-expansion cavity. The numerical solver was first validated for an experimental flow, the DLR strut-based scramjet combustor case. Shock wave structures and wall-pressure distribution from the numerical simulations were compared with experimental data and the numerical results were shown in good agreement with the available experimental data. Effects of the injection location on the flow and mixing process were then studied. It was found that with a long injection distance upstream the cavity, the fuel is transported much further into the main flow and a smaller subsonic zone is formed inside the cavity. Conversely, with a short injection distance, the fuel is entrained more into the cavity and a larger subsonic zone is formed inside the cavity, which is favorable for ignition in the cavity. For the rearwall-expansion cavity, it is suggested that the optimized ignition location with a long upstream injection distance should be in the bottom wall in the middle part of the cavity, while the optimized ignition location with a short upstream injection distance should be in the bottom wall in the front side of the cavity. By employing a cavity direct injection on the rear wall, the fuel mass fraction inside the cavity and the local turbulent intensity will both be increased due to this fueling, and it will also enhance the mixing process which will also lead to increased mixing efficiency. For the rearwall-expansion cavity, the combined injection scheme is expected to be an optimized injection scheme.

  19. Advanced tubular solid oxide fuel cells with high efficiency for internal reforming of hydrocarbon fuels

    NASA Astrophysics Data System (ADS)

    Cheekatamarla, Praveen K.; Finnerty, Caine M.; Du, Yanhai; Jiang, Juan; Dong, Jian; Dewald, P. G.; Robinson, C. R.

    Solid oxide fuel cells (SOFCs) constitute an attractive power-generation technology that converts chemical energy directly into electricity while causing little pollution. NanoDynamics Energy (NDE) Inc. has developed micro-tubular SOFC-based portable power generation systems that run on both gaseous and liquid fuels. In this paper, we present our next generation solid oxide fuel cells that exhibit total efficiencies in excess of 60% running on hydrogen fuel and 40+% running on readily available gaseous hydrocarbon fuels such as propane, butane etc. The advanced fuel cell design enables power generation at very high power densities and efficiencies (lower heating value-based) while reforming different hydrocarbon fuels directly inside the tubular SOFC without the aid of fuel pre-processing/reforming. The integrated catalytic layered SOFC demonstrated stable performance for >1000 h at high efficiency while running on propane fuel at sub-stoichiometric oxygen-to-fuel ratios. This technology will facilitate the introduction of highly efficient, reliable, fuel flexible, and lightweight portable power generation systems.

  20. A novel thin film solid oxide fuel cell for microscale energy conversion

    SciTech Connect

    Jankowiski, A; Morse, J

    1999-07-21

    A novel approach for the fabrication and assembly of a solid oxide fuel cell system is described which enables effective scaling of the fuel delivery, manifold, and fuel cell stack components for applications in miniature and microscale energy conversion. Electrode materials for solid oxide fuel cells are developed using sputter deposition techniques. A thin film anode is formed by co-deposition of nickel and yttria-stabilized zirconia (YSZ). This approach provides a mixed conducting inter-facial layer between the nickel electrode and electrolyte layer. Similarly, a thin film cathode is formed by co-deposition of silver and yttria-stabilized zirconia. Additionally, sputter deposition of yttria-stabilized zirconia thin film electrolyte enables high quality, continuous films to be formed having thicknesses on the order of 1-2 {micro}m. This will effectively lower the temperature of operation for the fuel cell stack significantly below the traditional ranges at which solid oxide electrolyte systems are operated (600-1000 C), thereby rendering this fuel cell system suitable for miniaturization, Scaling towards miniaturization is accomplished by utilizing novel micromachining approaches which allow manifold channels and fuel delivery system to be formed within the substrate which the thin film fuel cell stack is fabricated on, thereby circumventing the need for bulky manifold components which are not directly scalable. Methods to synthesize anodes for thin film solid-oxide fuel cells (TFSOFCs) from the electrolyte and a conductive material are developed using photolithographic patterning and physical vapor deposition. The anode layer must enable combination of the reactive gases, be conductive to pass the electric current, and provide mechanical support to the electrolyte and cathode layers. The microstructure and morphology desired for the anode layer should facilitate generation of maximum current density from the fuel cell. For these purposes, the parameters of the

  1. Energy-efficient air pollution controls for fossil-fueled plants: Technology assessment

    SciTech Connect

    Sayer, J.H.

    1995-06-01

    The 1990 Clean Air Act Amendments require most fossil-fuel fired power plants to reduce sulfur dioxide, nitrogen oxides, and particulate emissions. While emission-control equipment is available to help most of New York State`s 91 utility units in 31 power plants comply with the new regulations, technologies currently available consume energy, increase carbon dioxide emissions, reduce operating efficiency, and may produce large amounts of solid and/or semisolid byproducts that use additional energy for processing and disposal. This report discribes several pollution-control technologies that are more energy efficient compared to traditional technologies for controlling sulfur dioxide, nitrogen oxide, and particulates, that may have application in New York State. These technologies are either in commercial use, under development, or in the demonstration phase; This report also presents operating characteristics for these technologies and discusses solutions to dispose of pollution-control system byproducts. Estimated energy consumption for emission-control systems relative to a plant`s gross generating capacity is 3 to 5 for reducing up to 90% sulfur dioxide emissions from coal-fired plants. 0.5 to 2.5% for reducing nitrogen oxide emissions by up to 80% from all fossil-fuel fired plants; and 0.5 to 1.5 % for controlling particulate emissions from oil- and coal-fired plants. While fuel switching and/or cofiring with natural gas are options to reduce emissions, these techniques are not considered in this report; the discussion is limited to fossil-fueled steam-generating plants.

  2. Evaluation of a 2-MW carbonate fuel cell power plant fueled by landfill gas

    SciTech Connect

    Meade, D.B. ); Selander, S. ); Rastler, D.M. )

    1991-11-01

    This project assessed the technical and economic feasibility of operating an atmospheric pressure 2 MW carbonate fuel cell power plant on landfill gas. A commercially available low pressure gas pre-treatment system was identified for this application. System simulation studies were performed to identify component bottle-necks which would limit power production, or preclude system operation. An economic assessment was conducted to assess the competitiveness of the fuel cell system. The analysis confirmed the technical feasibility of operating Energy Research Corporation's 2MW fuel cell system on landfill gas. Resulting net electrical efficiency was 50% based on the fuel's lower heating value. Plant capital cost increased by {approximately}$180/kw; this was primarily for gas cleanup. Bus bar power costs for market entry and commercial fuel cell plants were found to be competitive with power produced from baseload coal plants in Minnesota.

  3. Comparative analysis of plant oil based fuels

    SciTech Connect

    Ziejewski, M.; Goettler, H.J.; Haines, H.; Huong, C.

    1995-12-31

    This paper presents the evaluation results from the analysis of different blends of fuels using the 13-mode standard SAE testing method. Six high oleic safflower oil blends, six ester blends, six high oleic sunflower oil blends, and six sunflower oil blends were used in this portion of the investigation. Additionally, the results from the repeated 13-mode tests for all the 25/75% mixtures with a complete diesel fuel test before and after each alternative fuel are presented.

  4. The Case for Natural Gas Fueled Solid Oxide Fuel Cell Power Systems for Distributed Generation

    SciTech Connect

    Chick, Lawrence A.; Weimar, Mark R.; Whyatt, Greg A.; Powell, Michael R.

    2015-02-01

    Natural-gas-fueled solid oxide fuel cell (NGSOFC) power systems yield electrical conversion efficiencies exceeding 60% and may become a viable alternative for distributed generation (DG) if stack life and manufacturing economies of scale can be realized. Currently, stacks last approximately 2 years and few systems are produced each year because of the relatively high cost of electricity from the systems. If mass manufacturing (10,000 units per year) and a stack life of 15 years can be reached, the cost of electricity from an NGSOFC system is estimated to be about 7.7 ¢/kWh, well within the price of commercial and residential retail prices at the national level (9.9-10¢/kWh and 11-12 ¢/kWh, respectively). With an additional 5 ¢/kWh in estimated additional benefits from DG, NGSOFC could be well positioned to replace the forecasted 59-77 gigawatts of capacity loss resulting from coal plant closures due to stricter emissions regulations and low natural gas prices.

  5. Neutronics benchmark for the Quad Cities-1 (Cycle 2) mixed oxide assembly irradiation

    SciTech Connect

    Fisher, S.E.; Difilippo, F.C.

    1998-04-01

    Reactor physics computer programs are important tools that will be used to estimate mixed oxide fuel (MOX) physics performance in support of weapons grade plutonium disposition in US and Russian Federation reactors. Many of the computer programs used today have not undergone calculational comparisons to measured data obtained during reactor operation. Pin power, the buildup of transuranics, and depletion of gadolinium measurements were conducted (under Electric Power Research Institute sponsorship) on uranium and MOX pins irradiated in the Quad Cities-1 reactor in the 1970`s. These measurements are compared to modern computational models for the HELIOS and SCALE computer codes. Good agreement on pin powers was obtained for both MOX and uranium pins. The agreement between measured and calculated values of transuranic isotopes was mixed, depending on the particular isotope.

  6. Direct chemical oxidation of mixed or toxic wastes

    SciTech Connect

    Balazs, G B; Cooper, J F; Farmer, J C; Lewis, P

    1999-05-01

    Direct Chemical Oxidation (DCO) is an ambient-pressure, low-temperature (<100 C), and aqueous-based process for general-purpose destruction of the organic fraction of hazardous or mixed waste. It uses the peroxydisulfate anion (S{sub 2}O{sub 8}{sup 2{minus}}) in acid or base solutions. The byproduct of the oxidation reaction, typically sodium or ammonium hydrogen sulfate, may be recycled electrolytically to produce the oxidant. The oxidation kinetic reaction is first order with respect to the peroxydisulfate concentration, expressed in equivalents. The rate constant is constant for nearly all dissolved organic compounds: k{sub a} = 0.01 {+-} 0.005 min{sup {minus}1}. This reflects a common rate-determining step, which is the decomposition of the peroxydisulfate anion into the chemically active derivative, the sulfate radical anion, SO{sub 4}{sup {minus}}. This decomposition is promoted in DCO by raising the operating temperature into the range of 80-100 C. Rates are given for approximately 30 substances with diverse functional groups at low concentrations, and for a number of solid and liquid wastes typical of nuclear and chemical industries. The process has been scale up for treatment studies on chlorinated hydrocarbons, in which the hydrolysis of solvent mixtures was followed by oxidation of products in a series of stirred tank reactors. Cost estimates, safety considerations, and a comprehensive bibliography are given.

  7. Advances in direct oxidation methanol fuel cells

    NASA Technical Reports Server (NTRS)

    Surampudi, S.; Narayanan, S. R.; Vamos, E.; Frank, H.; Halpert, G.; Laconti, Anthony B.; Kosek, J.; Prakash, G. K. Surya; Olah, G. A.

    1993-01-01

    Fuel cells that can operate directly on fuels such as methanol are attractive for low to medium power applications in view of their low weight and volume relative to other power sources. A liquid feed direct methanol fuel cell has been developed based on a proton exchange membrane electrolyte and Pt/Ru and Pt catalyzed fuel and air/O2 electrodes, respectively. The cell has been shown to deliver significant power outputs at temperatures of 60 to 90 C. The cell voltage is near 0.5 V at 300 mA/cm(exp 2) current density and an operating temperature of 90 C. A deterrent to performance appears to be methanol crossover through the membrane to the oxygen electrode. Further improvements in performance appear possible by minimizing the methanol crossover rate.

  8. Polymer solidification of mixed wastes at the Rocky Flats Plant

    SciTech Connect

    Faucette, A.M.; Logsdon, B.W.; Lucerna, J.J.; Yudnich, R.J.

    1994-02-01

    The Rocky Flats Plant is pursuing polymer solidification as a viable treatment option for several mixed waste streams that are subject to land disposal restrictions within the Resource Conservation and Recovery Act provisions. Tests completed to date using both surrogate and actual wastes indicate that polyethylene microencapsulation is a viable treatment option for several mixed wastes at the Rocky Flats Plant, including nitrate salts, sludges, and secondary wastes such as ash. Treatability studies conducted on actual salt waste demonstrated that the process is capable of producing waste forms that comply with all applicable regulatory criteria, including the Toxicity Characteristic Leaching Procedure. Tests have also been conducted to evaluate the feasibility of macroencapsulating certain debris wastes in polymers. Several methods and plastics have been tested for macroencapsulation, including post-consumer recycle and regrind polyethylene.

  9. Solid-oxide fuel cell electrolyte

    SciTech Connect

    Bloom, I.D.; Hash, M.C.; Krumpelt, M.

    1991-12-31

    This invention is comprised of a solid-oxide electrolyte operable at between 600{degrees}C and 800{degrees}C and a method of producing the solid-oxide electrolyte. The solid-oxide electrolyte comprises a combination of a compound having a 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.

  10. Solid-oxide fuel cell electrolyte

    DOEpatents

    Bloom, Ira D.; Hash, Mark C.; Krumpelt, Michael

    1993-01-01

    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.

  11. Catalytic oxidation of very fuel rich mixtures

    NASA Technical Reports Server (NTRS)

    Brabbs, T. A.

    1983-01-01

    The objective of this research is to demonstrate the feasibility of using a catalytic reactor as a tool to study soot formation from the fuel rich side of the soot limit (null set = 3 - 6). The experimental approach to be taken in the first phase of the research is to document that a hydrocarbon fuel can be burnt at very rich equivalence ratios without forming soot. A simple mono-component fuel, iso-octane, will be used as the test fuel. To insure that combustion is uniform across the catalyst bed, measurements will be made of the fuel-air equivalence ratio profile across the inlet and the temperature and product distribution across the outlet. Phase Two will be to use this environment as a testing ground for determining the effect the structure of a hydrocarbon fuel has on its tendency to form soot. Various amounts of organic compounds such as benzene will be added to the iso-octane and the reaction products studied. Other compounds to be tested will xylene, toluene, and naphthalene.

  12. Cost and quality of fuels for electric plants 1993

    SciTech Connect

    Not Available

    1994-07-01

    The Cost and Quality of Fuels for Electric Utility Plants (C&Q) presents an annual summary of statistics at the national, Census division, State, electric utility, and plant levels regarding the quantity, quality, and cost of fossil fuels used to produce electricity. The purpose of this publication is to provide energy decision-makers with accurate and timely information that may be used in forming various perspectives on issues regarding electric power.

  13. Treatment of oxide spent fuel using the lithium reduction process

    SciTech Connect

    Karell, E.J.; Pierce, R.D.; Mulcahey, T.P.

    1996-05-01

    The wide variety in the composition of DOE spent nuclear fuel complicates its long-term disposition because of the potential requirement to individually qualify each type of fuel for repository disposal. Argonne National Laboratory (ANL) has developed the electrometallurgical treatment technique to convert all of these spent fuel types into a single set of disposal forms, simplifying the qualification process. While metallic fuels can be directly processed using the electrometallurgical treatment technique, oxide fuels must first be reduced to the metallic form. The lithium reduction process accomplishes this pretreatment. In the lithium process the oxide components of the fuel are reduced using lithium at 650 C in the presence of molten LiCl, yielding the corresponding metals and Li{sub 2}O. The reduced metal components are then separated from the LiCl salt phase and become the feed material for electrometallurgical treatment. A demonstration test of the lithium reduction process was successfully conducted using a 10-kg batch of simulated oxide spent fuel and engineering-scale equipment specifically constructed for that purpose. This paper describes the lithium process, the equipment used in the demonstration test, and the results of the demonstration test.

  14. Nitric oxide and plant iron homeostasis.

    PubMed

    Buet, Agustina; Simontacchi, Marcela

    2015-03-01

    Like all living organisms, plants demand iron (Fe) for important biochemical and metabolic processes. Internal imbalances, as a consequence of insufficient or excess Fe in the environment, lead to growth restriction and affect crop yield. Knowledge of signals and factors affecting each step in Fe uptake from the soil and distribution (long-distance transport, remobilization from old to young leaves, and storage in seeds) is necessary to improve our understanding of plant mineral nutrition. In this context, the role of nitric oxide (NO) is discussed as a key player in maintaining Fe homeostasis through its cross talk with hormones, ferritin, and frataxin and the ability to form nitrosyl-iron complexes.

  15. A stochastic model of turbulent mixing with chemical reaction: Nitric oxide formulation in a plug-flow burner

    NASA Technical Reports Server (NTRS)

    Flagan, R. C.; Appleton, J. P.

    1973-01-01

    A stochastic model of turbulent mixing was developed for a reactor in which mixing is represented by n-body fluid particle interactions. The model was used to justify the assumption (made in previous investigations of the role of turbulent mixing on burner generated thermal nitric oxide and carbon monoxide emissions) that for a simple plug flow reactor, composition nonuniformities can be described by a Gaussian distribution function in the local fuel:air equivalence ratio. Recent extensions of this stochastic model to include the combined effects of turbulent mixing and secondary air entrainment on thermal generation of nitric oxide in gas turbine combustors are discussed. Finally, rate limited upper and lower bounds of the nitric oxide produced by thermal fixation of molecular nitrogen and oxidation of organically bound fuel nitrogen are estimated on the basis of the stochastic model for a plug flow burner; these are compared with experimental measurements obtained using a laboratory burner operated over a wide range of test conditions; good agreement is obtained.

  16. CFD Analysis of Mixing Characteristics of Several Fuel Injectors at Hypervelocity Flow Conditions

    NASA Technical Reports Server (NTRS)

    Drozda, Tomasz G.; Drummond, J. Philip; Baurle, Robert A.

    2016-01-01

    CFD analysis is presented of the mixing characteristics and performance of three fuel injectors at hypervelocity flow conditions. The calculations were carried out using the VULCAN-CFD solver and Reynolds-Averaged Simulations (RAS). The high Mach number flow conditions match those proposed for the planned experiments conducted as a part of the Enhanced Injection and Mixing Project (EIMP) at the NASA Langley Research Center. The EIMP aims to investigate scramjet fuel injection and mixing physics, improve the understanding of underlying physical processes, and develop enhancement strategies and functional relationships relevant to flight Mach numbers greater than eight. Because of the high Mach number flow considered, the injectors consist of a fuel placement device, a strut; and a fluidic vortical mixer, a ramp. These devices accomplish the necessary task of distributing and mixing fuel into the supersonic cross-flow albeit via different strategies. Both of these devices were previously studied at lower flight Mach numbers where they exhibited promising performance in terms of mixing efficiency and total pressure recovery. For comparison, a flush-wall injector is also included. This type of injector generally represents the simplest method of introducing fuel into a scramjet combustor, however, at high flight Mach number conditions, the dynamic pressure needed to induce sufficient fuel penetration may be difficult to achieve along with other requirements such as achieving desired levels of fuel-to-air mixing at the required equivalence ratio. The three injectors represent the baseline configurations planned for the experiments. The current work discusses the mixing flow field behavior and differences among the three fuel injectors, mixing performance as described by the mixing efficiency and the total pressure recovery, and performance considerations based on the thrust potential.

  17. The low-temperature partial-oxidation reforming of fuels for transportation fuel cell systems

    SciTech Connect

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

    1996-12-31

    Passenger cars powered by fuel cell propulsion systems with high efficiency offer superior fuel economy, very low to zero pollutant emissions, and the option to operate on alternative and/or renewable fuels. Although the fuel cell operates on hydrogen, a liquid fuel such as methanol or gasoline is more attractive for automotive use because of the convenience in handling and vehicle refueling. Such a liquid fuel must be dynamically converted (reformed) to hydrogen on board the vehicle in real time to meet fluctuating power demands. This paper describes the low-temperature Argonne partial-oxidation reformer (APOR) developed for this application. The APOR is a rapid-start, compact, lightweight, catalytic device that is efficient and dynamically responsive. The reformer is easily controlled by varying the feed rates of the fuel, water, and air to satisfy the rapidly changing system power demands during the vehicle`s driving cycle.

  18. Prospects for advanced coal-fuelled fuel cell power plants

    NASA Astrophysics Data System (ADS)

    Jansen, D.; Vanderlaag, P. C.; Oudhuis, A. B. J.; Ribberink, J. S.

    1994-04-01

    As part of ECN's in-house R&D programs on clean energy conversion systems with high efficiencies and low emissions, system assessment studies have been carried out on coal gasification power plants integrated with high-temperature fuel cells (IGFC). The studies also included the potential to reduce CO2 emissions, and to find possible ways for CO2 extraction and sequestration. The development of this new type of clean coal technology for large-scale power generation is still far off. A significant market share is not envisaged before the year 2015. To assess the future market potential of coal-fueled fuel cell power plants, the promise of this fuel cell technology was assessed against the performance and the development of current state-of-the-art large-scale power generation systems, namely the pulverized coal-fired power plants and the integrated coal gasification combined cycle (IGCC) power plants. With the anticipated progress in gas turbine and gas clean-up technology, coal-fueled fuel cell power plants will have to face severe competition from advanced IGCC power plants, despite their higher efficiency.

  19. Doped CeO2-LaFeO3 composite oxide as an active anode for direct hydrocarbon-type solid oxide fuel cells.

    PubMed

    Shin, Tae Ho; Ida, Shintaro; Ishihara, Tatsumi

    2011-12-01

    Direct utilization of hydrocarbon and other renewable fuels is one of the most important issues concerning solid oxide fuel cells (SOFCs). Mixed ionic and electronic conductors (MIECs) have been explored as anode materials for direct hydrocarbon-type SOFCs. However, electrical conductivity of the most often reported MIEC oxide electrodes is still not satisfactory. As a result, mixed-conducting oxides with high electrical conductivity and catalytic activity are attracting considerable interest as an alternative anode material for noncoke depositing anodes. In this study, we examine the oxide composite Ce(Mn,Fe)O(2)-La(Sr)Fe(Mn)O(3) for use as an oxide anode in direct hydrocarbon-type SOFCs. High performance was demonstrated for this composite oxide anode in direct hydrocarbon-type SOFCs, showing high maximum power density of approximately 1 W cm(-2) at 1073 K when propane and butane were used as fuel. The high power density of the cell results from the high electrical conductivity of the composite oxide in hydrocarbon and the high surface activity in relation to direct hydrocarbon oxidation.

  20. SrFe0.75Mo0.25O3-δ impregnated 430L alloys for efficient fuel oxidation in metal supported solid oxide fuel cells

    NASA Astrophysics Data System (ADS)

    Zhou, Yucun; Meng, Xie; Yuan, Chun; Luo, Ting; Ye, Xiaofeng; Li, Junliang; Wang, Shaorong; Zhan, Zhongliang

    2014-12-01

    Here we report a novel SrFe0.75Mo0.25O3-δ (SFMO)-430L composite anode for the application in the metal supported solid oxide fuel cells. Such an anode is prepared by coating a thin nano porous and mixed electronic-ionic conducting SFMO layer onto the internal surface of a micron porous 430L alloy backbone. The area specific polarization resistance of the composite anode for hydrogen oxidation can be as low as 0.11 Ω cm2 at 800 °C. The electronic conductivity of the 430L alloy support is found to be critically important for promoting rapid hydrogen oxidation kinetics and attaining such a low polarization resistance as the fuel cell anode. A metal-supported fuel cell with the SFMO impregnated 430L composite anode exhibits outstanding power densities at 800 °C, e.g., 0.81 W cm-2 in hydrogen and 0.31 W cm-2 in iso-octane. Preliminary results show that the present SFMO-430L composite anode exhibits much higher tolerance for coking formation than the traditional Ni-based anode.

  1. Remotex and servomanipulator needs in nuclear fuel reprocessing plants

    SciTech Connect

    Garin, J.

    1981-01-01

    Work on the conceptual design of a pilot-scale plant for reprocessing breeder reactor fuels is being performed at Oak Ridge National Laboratory. The plant design will meet all current federal regulations for repocessing plants and will serve as prototype for future production plants. A unique future of the concept is the incorporation of totally remote operation and maintenance of the process equipment within a large barn-like hot cell. This approach, caled Remotex, utilizes servomanipulators coupled with television viewing to extend man's capabilities into the hostile cell environment. The Remotex concept provides significant improvements for fuel reprocessing plants and other nuclear facilities in the areas of safeguarding nuclear materials, reducing radiation exposure, improving plant availability, recovering from unplanned events, and plant decommissioning.

  2. Serially connected solid oxide fuel cells having monolithic cores

    SciTech Connect

    Herceg, Joseph E.

    1987-01-01

    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.

  3. Nitrogen oxide abatement by distributed fuel addition

    SciTech Connect

    Wendt, J.O.L.; Mereb, J.B.

    1991-09-20

    Reburning is examined as a means of NO{sub x} destruction in a 17 kW down-fired pulverized coal combustor. In reburning, a secondary fuel is introduced downstream of the primary flame to produce a reducing zone, favorable to NO destruction, and air is introduced further downstream to complete the combustion. Emphasis is on natural gas reburning and a bituminous coal primary flame. A parametric examination of reburning employing a statistical experimental design, is conducted, complemented by detailed experiments. Mechanisms governing the inter-conversion of nitrogenous species in the fuel rich reburn zone is explored. The effect of reburning on N{sub 2}O emissions, the effect of primary flame mode (premixed and diffusion) and the effect of distributing the reburning fuel, are also investigated.

  4. Five Kilowatt Solid Oxide Fuel Cell/Diesel Reformer

    SciTech Connect

    Dennis Witmer; Thomas Johnson

    2008-12-31

    Reducing fossil fuel consumption both for energy security and for reduction in global greenhouse emissions has been a major goal of energy research in the US for many years. Fuel cells have been proposed as a technology that can address both these issues--as devices that convert the energy of a fuel directly into electrical energy, they offer low emissions and high efficiencies. These advantages are of particular interest to remote power users, where grid connected power is unavailable, and most electrical power comes from diesel electric generators. Diesel fuel is the fuel of choice because it can be easily transported and stored in quantities large enough to supply energy for small communities for extended periods of time. This projected aimed to demonstrate the operation of a solid oxide fuel cell on diesel fuel, and to measure the resulting efficiency. Results from this project have been somewhat encouraging, with a laboratory breadboard integration of a small scale diesel reformer and a Solid Oxide Fuel Cell demonstrated in the first 18 months of the project. This initial demonstration was conducted at INEEL in the spring of 2005 using a small scale diesel reformer provided by SOFCo and a fuel cell provided by Acumentrics. However, attempts to integrate and automate the available technology have not proved successful as yet. This is due both to the lack of movement on the fuel processing side as well as the rather poor stack lifetimes exhibited by the fuel cells. Commercial product is still unavailable, and precommercial devices are both extremely expensive and require extensive field support.

  5. Electrochemical properties of mixed conducting (La,M)(CoFe) oxide perovskites (M=3DSr, Ca, and Ba)

    SciTech Connect

    Stevenson, J.W.; Armstrong, T.R.; Bates, J.L.

    1996-04-01

    Electrical properties and oxygen permeation properties of solid mixed-conducting electrolytes (La,M)(CoFe) oxide perovskites (M=3DSr, Ca, and Ba) have been characterized. These materials are potentially useful as passive membranes to separate high purity oxygen from air and as the cathode in a fuel cell. Dilatometric linear expansion measurements were performed as a function of temperature and oxygen partial pressure to evaluate the stability.

  6. Oxidation and formation of deposit precursors in hydrocarbon fuels

    NASA Technical Reports Server (NTRS)

    Mayo, F. R.; Lan, B.; Cotts, D. B.; Buttrill, S. E., Jr.; St.john, G. A.

    1983-01-01

    The oxidation of two jet turbine fuels and some pure hydrocarbons was studied at 130 C with and without the presence of small amounts of N-methyl pyrrole (NMP) or indene. Tendency to form solid-deposit precursors was studied by measuring soluble gum formation as well as dimer and trimer formation using field ionization mass spectrometry. Pure n-dodecane oxidized fastest and gave the smallest amount of procursors. An unstable fuel oil oxidized much slower but formed large amounts of precursors. Stable Jet A fuel oxidized slowest and gave little precursors. Indene either retarded or accelerated the oxidation of n-dodecane, depending on its concentration, but always caused more gum formation. The NMP greatly retarded n-dodecane oxidation but accelerated Jet A oxidation and greatly increased the latter's gum formation. In general, the additive reacted faster and formed most of the gum. Results are interpreted in terms of classical cooxidation theory. The effect of oxygen pressure on gum formation is also reported.

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

    SciTech Connect

    Unknown

    2003-06-01

    This report summarizes the progress made during the September 2001-March 2002 reporting period under Cooperative Agreement DE-FC26-01NT41245 for the U. S. Department of Energy, National Energy Technology Laboratory (DOE/NETL) entitled ''Solid State Energy Conversion Alliance (SECA) Solid Oxide Fuel Cell Program''. 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. The overall objective of the program is to demonstrate a modular SOFC system that can be configured to create highly efficient, cost-competitive, and environmentally benign power plants tailored to specific markets. When fully developed, the system will meet the efficiency, performance, life, and cost goals for future commercial power plants.

  8. Recommended guidelines for solid fuel use in cement plants

    SciTech Connect

    Young, G.L.; Jayaraman, H.; Tseng, H.

    2007-07-01

    Pulverized solid fuel use at cement plants in North America is universal and includes bituminous and sub-bituminous coal, petroleum coke, and any combination of these materials. Provided are guidelines for the safe use of pulverized solid fuel systems in cement plants, including discussion of the National Fire Protection Association and FM Global fire and explosion prevention standards. Addressed are fire and explosion hazards related to solid fuel use in the cement industry, fuel handling and fuel system descriptions, engineering design theory, kiln system operations, electrical equipment, instrumentation and safety interlock issues, maintenance and training, and a brief review of code issues. New technology on fire and explosion prevention including deflagration venting is also presented.

  9. A computational investigation of fuel mixing in a hypersonic scramjet

    NASA Technical Reports Server (NTRS)

    Fathauer, Brett W.; Rogers, R. C.

    1993-01-01

    A parabolized, Navier-Stokes code, SHIP3D, is used to numerically investigate the mixing between air injection and hydrogen injection from a swept ramp injector configuration into either a mainstream low-enthalpy flow or a hypervelocity test flow. The mixing comparisons between air and hydrogen injection reveal the importance of matching injectant-to-mainstream mass flow ratios. In flows with the same injectant-to-mainstream dynamic pressure ratio, the mixing definition was altered for the air injection cases. Comparisons of the computed results indicate that the air injection cases overestimate the mixing performance associated with hydrogen injection simulation. A lifting length parameter, to account for the time a fluid particle transverses through the mixing region, is defined and used to establish a connection of injectant mixing in hypervelocity flows, based on nonreactive, low-enthalpy flows.

  10. Americium characterization by X-ray fluorescence and absorption spectroscopy in plutonium uranium mixed oxide

    NASA Astrophysics Data System (ADS)

    Degueldre, Claude; Cozzo, Cedric; Martin, Matthias; Grolimund, Daniel; Mieszczynski, Cyprian

    2013-06-01

    Plutonium uranium mixed oxide (MOX) fuels are currently used in nuclear reactors. The actinides in these fuels need to be analyzed after irradiation for assessing their behaviour with regard to their environment and the coolant. In this work the study of the atomic structure and next-neighbour environment of Am in the (Pu,U)O2 lattice in an irradiated (60 MW d kg-1) MOX sample was performed employing micro-X-ray fluorescence (µ-XRF) and micro-X-ray absorption fine structure (µ-XAFS) spectroscopy. The chemical bonds, valences and stoichiometry of Am (˜0.66 wt%) are determined from the experimental data gained for the irradiated fuel material examined in its peripheral zone (rim) of the fuel. In the irradiated sample Am builds up as Am3+ species within an [AmO8]13- coordination environment (e.g. >90%) and no (<10%) Am(IV) or (V) can be detected in the rim zone. The occurrence of americium dioxide is avoided by the redox buffering activity of the uranium dioxide matrix.

  11. Apparatus for mixing fuel in a gas turbine

    DOEpatents

    Uhm, Jong Ho; Johnson, Thomas Edward

    2015-04-21

    A combustor nozzle includes an inlet surface and an outlet surface downstream from the inlet surface, wherein the outlet surface has an indented central portion. A plurality of fuel channels are arranged radially outward of the indented central portion, wherein the plurality of fuel channels extend through the outlet surface.

  12. Pressurized solid oxide fuel cell testing

    SciTech Connect

    Basel, R.A.; Pierre, J.F.

    1995-08-01

    The goals of the SOFC pressurized test program are to obtain cell voltage versus current (VI) performance data as a function of pressure; to evaluate the effects of operating parameters such as temperature, air stoichiometry, and fuel utilization on cell performance, and to demonstrate long term stability of the SOFC materials at elevated pressures.

  13. Monte-Carlo Code (MCNP) Modeling of the Advanced Test Reactor Applicable to the Mixed Oxide (MOX) Test Irradiation

    SciTech Connect

    G. S. Chang; R. C. Pederson

    2005-07-01

    Mixed oxide (MOX) test capsules prepared with weapons-derived plutonium have been irradiated to a burnup of 50 GWd/t. The MOX fuel was fabricated at Los Alamos National Laboratory by a master-mix process and has been irradiated in the Advanced Test Reactor (ATR) at the Idaho National Laboratory (INL). Previous withdrawals of the same fuel have occurred at 9, 21, 30, and 40 GWd/t. Oak Ridge National Laboratory (ORNL) manages this test series for the Department of Energy’s Fissile Materials Disposition Program (FMDP). The fuel burnup analyses presented in this study were performed using MCWO, a welldeveloped tool that couples the Monte Carlo transport code MCNP with the isotope depletion and buildup code ORIGEN-2. MCWO analysis yields time-dependent and neutron-spectrum-dependent minor actinide and Pu concentrations for the ATR small I-irradiation test position. The purpose of this report is to validate both the Weapons-Grade Mixed Oxide (WG-MOX) test assembly model and the new fuel burnup analysis methodology by comparing the computed results against the neutron monitor measurements.

  14. Fuel and soot oxidation in diesel-like conditions

    SciTech Connect

    Cavaliere, A.; Barbella, R.; Ciajolo, A.; D`Anna, A.; Ragucci, R.

    1994-12-31

    Diesel combustion has been studied under simplified experimental conditions in a nearly quiescent, high-temperature (900 K), high-pressure (4 MPa) environment by means of two-dimensional (2D) laser light scattering techniques and chemical analysis of gaseous and condensable material sampled by a fast-acting valve. Two model fuels, constituted of a simple alkane hydrocarbon (tetradecane (TD)) and an aromatic/aliphatic mixture ({alpha}-methylnaphthalene/tetradecane), have been used in order to study the effect of the fuel specificity on the combustion process. Temporal profiles of the scattering intensity and of the evolution of the oxidation progress evaluated by CO and CO{sub 2} determinations, have shown the same behavior independently on the fuel type and on the sampling location. For both fuels, the combustion proceeds through the formation of CO and subsequent oxidation to CO{sub 2}, which is anticipated with respect to the appearance of a scattering signal due to soot formation and is almost completed in correspondence of the beginning of soot oxidation. The early phase of the latter process takes place in correspondence of the CO depletion when OH radicals become available. The importance of this result consists in the recognition that mechanisms of soot oxidation by an OH attack can realistically occur in diesel engine combustion and that this is the only pathway through which soot oxidation takes place in characteristic timescales comparable to those of its formation.

  15. Preparation of uniform nanoparticles of ultra-high purity metal oxides, mixed metal oxides, metals, and metal alloys

    DOEpatents

    Woodfield, Brian F.; Liu, Shengfeng; Boerio-Goates, Juliana; Liu, Qingyuan; Smith, Stacey Janel

    2012-07-03

    In preferred embodiments, metal nanoparticles, mixed-metal (alloy) nanoparticles, metal oxide nanoparticles and mixed-metal oxide nanoparticles are provided. According to embodiments, the nanoparticles may possess narrow size distributions and high purities. In certain preferred embodiments, methods of preparing metal nanoparticles, mixed-metal nanoparticles, metal oxide nanoparticles and mixed-metal nanoparticles are provided. These methods may provide tight control of particle size, size distribution, and oxidation state. Other preferred embodiments relate to a precursor material that may be used to form nanoparticles. In addition, products prepared from such nanoparticles are disclosed.

  16. LG Solid Oxide Fuel Cell (SOFC) Model Development

    SciTech Connect

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

    2013-05-31

    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.

  17. Waste fuel, EMS may save plant $1M yearly

    SciTech Connect

    Barber, J.

    1982-05-24

    A mixture of paper trash and coal ash fueling an Erie, Pa. General Electric plant and a Network 90 microprocessor-based energy-management system (EMS) to optimize boiler efficiency will cost about $3 million and have a three-to-four-year payback. Over half the savings will come from the avoided costs of burning plant-generated trash. The EMS system will monitor fuel requirements in the boiler and compensate for changes in steam demand. It will also monitor plant electrical needs and control the steam diverted for cogeneration. (DCK)

  18. Proline as a fuel for insect flight: enhancing carbohydrate oxidation in hymenopterans.

    PubMed

    Teulier, Loïc; Weber, Jean-Michel; Crevier, Julie; Darveau, Charles-A

    2016-07-13

    Bees are thought to be strict users of carbohydrates as metabolic fuel for flight. Many insects, however, have the ability to oxidize the amino acid proline at a high rate, which is a unique feature of this group of animals. The presence of proline in the haemolymph of bees and in the nectar of plants led to the hypothesis that plants may produce proline as a metabolic reward for pollinators. We investigated flight muscle metabolism of hymenopteran species using high-resolution respirometry performed on permeabilized muscle fibres. The muscle fibres of the honeybee, Apis mellifera, do not have a detectable capacity to oxidize proline, as those from the migratory locust, Locusta migratoria, used here as an outgroup representative. The closely related bumblebee, Bombus impatiens, can oxidize proline alone and more than doubles its respiratory capacity when proline is combined with carbohydrate-derived substrates. A distant wasp species, Vespula vulgaris, exhibits the same metabolic phenotype as the bumblebee, suggesting that proline oxidation is common in hymenopterans. Using a combination of mitochondrial substrates and inhibitors, we further show that in B. impatiens, proline oxidation provides reducing equivalents and electrons directly to the electron transport system. Together, these findings demonstrate that some bee and wasp species can greatly enhance the oxidation of carbohydrates using proline as fuel for flight. PMID:27412285

  19. Effects of injection angle and pressure on mixing performance of fuel injection via various geometries for upstream-fuel-injected scramjets

    NASA Astrophysics Data System (ADS)

    Ogawa, Hideaki

    2016-11-01

    Effective fuel injection and mixing is of crucial importance for reliable operation of scramjet engines, where fuel must be injected into high-speed crossflow and mixed with air at an extremely short timescale. This paper presents the results of a numerical study that investigates the effects of the injection angle and pressure for various orifice shapes on fuel mixing characteristics into hypersonic airflow at Mach 5, aiming at the application to scramjet operation with upstream fuel injection at Mach 10. The mixing performance has been evaluated with respect to the mixing efficiency, total pressure recovery, fuel penetration, and streamwise circulation. Significant influence of the injection angle and intensity on the mixing has been observed in conjunction with the geometric features of the injector orifice. An additional performance parameter, namely the mixing vorticity effectiveness, has been found to be an effective measure to quantify the contribution of the streamwise vorticity in mixing enhancement.

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

    NASA Astrophysics Data System (ADS)

    Braun, Robert Joseph

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

  1. 40 CFR 721.10148 - Acryloxy alkanoic alkane derivative with mixed metal oxides (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... with mixed metal oxides (generic). 721.10148 Section 721.10148 Protection of Environment ENVIRONMENTAL... mixed metal oxides (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as acryloxy alkanoic alkane derivative with mixed...

  2. 40 CFR 721.10148 - Acryloxy alkanoic alkane derivative with mixed metal oxides (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... with mixed metal oxides (generic). 721.10148 Section 721.10148 Protection of Environment ENVIRONMENTAL... mixed metal oxides (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as acryloxy alkanoic alkane derivative with mixed...

  3. 40 CFR 721.10148 - Acryloxy alkanoic alkane derivative with mixed metal oxides (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... with mixed metal oxides (generic). 721.10148 Section 721.10148 Protection of Environment ENVIRONMENTAL... mixed metal oxides (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as acryloxy alkanoic alkane derivative with mixed...

  4. Solid oxide fuel cell steam reforming power system

    SciTech Connect

    Chick, Lawrence A.; Sprenkle, Vincent L.; Powell, Michael R.; Meinhardt, Kerry D.; Whyatt, Greg A.

    2013-03-12

    The present invention is a Solid Oxide Fuel Cell Reforming Power System that utilizes adiabatic reforming of reformate within this system. By utilizing adiabatic reforming of reformate within the system the system operates at a significantly higher efficiency than other Solid Oxide Reforming Power Systems that exist in the prior art. This is because energy is not lost while materials are cooled and reheated, instead the device operates at a higher temperature. This allows efficiencies higher than 65%.

  5. Hydrogen as an activating fuel for a tidal power plant

    NASA Astrophysics Data System (ADS)

    Gorlov, A. M.

    Tidal projects, offering a clean, inexhaustible, and fairly predictable energy source, require a system for accumulating energy for off-peak periods. Hydrogen produced by electrolysis during off-peak power plant operation can be used as an activating fuel to furnish the plant during peak load demands. Tidal energy is converted into compressed air energy by special chambers on the ocean bed. This compressed air can be heated by combustion of the stored hydrogen and expanded through high speed gas turbine generators. For off-peak periods, the energy of non-heated compressed air is used for the production of hydrogen fuel. The amount of fuel produced at this time is enough for power plant operation during two peak hours, with three times greater plant capacity. The hydrogen fuel storage method does have energy losses and requires extra capital investment for electrolysis and hydrogen storage equipment. It does not, however, require a gas turbine oil fuel, as does the air compressed storage method, nor a low-speed heavy hydro-turbine, as does the hydro-pumped method. Moreover, the gas turbine can be used for both production and consumption of hydrogen fuel.

  6. Multi-tube fuel nozzle with mixing features

    SciTech Connect

    Hughes, Michael John

    2014-04-22

    A system includes a multi-tube fuel nozzle having an inlet plate and a plurality of tubes adjacent the inlet plate. The inlet plate includes a plurality of apertures, and each aperture includes an inlet feature. Each tube of the plurality of tubes is coupled to an aperture of the plurality of apertures. The multi-tube fuel nozzle includes a differential configuration of inlet features among the plurality of tubes.

  7. Yttria-stabilized zirconia solid oxide electrolyte fuel cells, monolithic solid oxide fuel cells. Quarterly report, April--June 1989

    SciTech Connect

    Not Available

    1989-12-31

    Small cell size, thin ceramic components, and high operating temperature are the key features of the MSOFC. The small size of individual cells in the monolithic structure increases the active surface area. For example, an MSOFC with channels about 1 mm in diameter has a ratio of active surface area to volume of about 9.4 sq cm/cu cm. This is about seven times the ratio for conventional fuel cells. On this basis alone, an MSOFC with a channel diameter of 1 mm should produce the same power as a conventional fuel cell seven times as large. The high current density of the MSOFC results from the small cell size and ensuing low internal resistance. The current density is high at the fuel inlet end of the fuel channel where the thermodynamic driving force (Nernst potential) is highest. Similarly, the current density is low at the outlet end of the fuel channel where the Nernst potential is lowest. Because of the high operating temperature of the MSOFC (1000{degrees}C),hydrocarbon fuels can be reformed in the fuel channels. The reform reaction produces hydrogen which is consumed by the fuel cell. Catalytic reforming of methane and natural gas within a solid oxide fuel cell has been demonstrated.

  8. Iron-tellurium-selenium mixed oxide catalysts for the selective oxidation of propylene to acrolein

    SciTech Connect

    Patel, B.M.; Price, G.L. )

    1990-05-01

    This paper reports on iron-tellurium-selenium mixed oxide catalysts prepared by coprecipitation from aqueous solution investigated for the propylene to acrolein reaction in the temperature range 543-773 K. Infrared spectroscopy, electron dispersive X-ray analysis, X-ray diffraction, and isotopic tracer techniques have also been employed to characterize this catalytic system. Properties of the Fe-Te-Se mixed oxide catalysts have been compared with Fe-Te mixed oxides in an effort to deduce the functionality of Se. The selenium in the Fe-Te-Se-O catalyst has been found to be the hydrocarbon activating site. The activation energies for the acrolein and carbon dioxide formation are 71 and 54 kJ/mol, respectively. Reactions carried out with {sup 18}O{sub 2} have shown lattice oxygen to be primarily responsible for the formation of both acrolein and carbon dioxide. The initial and rate-determining step for acrolein formation is hydrogen abstraction as determined by an isotope effect associated with the C{sub 3}D{sub 6} reaction. No isotope effect is observed for carbon dioxide formation from C{sub 3}D{sub 6} suggesting that CO{sub 2} is formed by parallel, not consecutive, oxidation of propylene.

  9. NITROUS OXIDE EMISSIONS FROM FOSSIL FUEL COMBUSTION

    EPA Science Inventory

    The role of coal combustion as a significant global source of nitrous oxide (N2O) emissions was reexamined through on-line emission measurements from six pulverized-coal-fired utility boilers and from laboratory and pilot-scale combustors. The full-scale utility boilers yielded d...

  10. Oxidation control of fluxes for mixed-valent inorganic oxide materials synthesis

    NASA Astrophysics Data System (ADS)

    Schrier, Marc David

    This dissertation is concerned with controlling the flux synthesis and ensuing physical properties of mixed-valence metal oxides. Molten alkali metal nitrates and hydroxides have been explored to determine and exploit their variable redox chemistries for the synthesis of mixed-valent oxide materials. Cationic and anionic additives have been utilized in these molten salts to control the relative concentrations of the redox-active species present to effectively tune and cap the electrochemical potential of the flux. Atoms like bismuth, copper, and manganese are capable of providing different numbers of electrons for bonding. With appropriate doping near the metal-insulator transition, many of these mixed-valent inorganic metal oxides exhibit extraordinary electronic and magnetic properties. Traditionally, these materials have been prepared by classical high temperature solid state routes where microscopic homogeneity is hard to attain. In these routes, the starting composition dictates the doping level, and in turn, the formal oxidation state achieved. Molten flux syntheses developed in this work have provided the potential for preparing single-phase, homogeneous, and crystalline materials. The redox-active fluxes provide a medium for enhanced doping and mixed-valency control in which the electrochemical potential adjusts the formal oxidation state, and the doping takes place to maintain charge neutrality. The two superconductor systems investigated are: (1) the potassium-doped barium bismuth oxides, and (2) the alkali metal- and alkaline earth metal-doped lanthanum copper oxides. Controlled oxidative doping has been achieved in both systems by two different approaches. The superconducting properties of these materials have been assessed, and the materials have been characterized by powder X-ray diffraction and e-beam microprobe elemental analyses. In the course of these studies, several other materials have been identified. Analysis of these materials, and the

  11. Effects of Humidity on Solid Oxide Fuel Cell Cathodes

    SciTech Connect

    Hardy, John S.; Stevenson, Jeffry W.; Singh, Prabhakar; Mahapatra, Manoj K.; Wachsman, E. D.; Liu, Meilin; Gerdes, Kirk R.

    2015-03-17

    This report summarizes results from experimental studies performed by a team of researchers assembled on behalf of the Solid-state Energy Conversion Alliance (SECA) Core Technology Program. Team participants employed a variety of techniques to evaluate and mitigate the effects of humidity in solid oxide fuel cell (SOFC) cathode air streams on cathode chemistry, microstructure, and electrochemical performance.

  12. Nanofiber Scaffold for Cathode of Solid Oxide Fuel Cell

    SciTech Connect

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

    2010-10-01

    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.

  13. 4. Historic photo of fuel and oxidant tanks in hilltop ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. Historic photo of fuel and oxidant tanks in hilltop area of rocket engine test facility. 1956. On file at NASA Plumbrook Research Center, Sandusky, Ohio. NASA GRC photo number C-1956-160D. - Rocket Engine Testing Facility, NASA Glenn Research Center, Cleveland, Cuyahoga County, OH

  14. Method of fabricating a monolithic solid oxide fuel cell

    DOEpatents

    Minh, N.Q.; Horne, C.R.

    1994-03-01

    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. 10 figures.

  15. Method of fabricating a monolithic solid oxide fuel cell

    DOEpatents

    Minh, Nguyen Q.; Horne, Craig R.

    1994-01-01

    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.

  16. Evaluation of oxidative corrosion in diesel fuel lubricated contacts

    NASA Astrophysics Data System (ADS)

    Lacey, P. I.

    1994-04-01

    Previous studies have demonstrated that the durability of some fuel injection systems on compression-ignition engines will be adversely affected by fuels of sufficiently low lubricity. However, no widely accepted lubricity measure is available; indeed, the wear mechanisms present have not been conclusively defined. The results of the present study indicate that oxidative is the predominant mechanism with very highly processed fuels, resulting in catastrophic wear and rapid failure. Less highly refined fuels contain natural corrosion inhibitors and produce alternate wear mechanisms that may still affect long-term durability. A laboratory test procedure directed toward the oxidative wear mechanism was evaluated and a number of modifications suggested. The resulting test produced good correlation with the full-scale pump and appeared to correlate with the criteria necessary for oxidative corrosion. However, it is recognized that this single test procedure may not fully define the lubricity requirements of the injection system, particularly in the absence of oxidative corrosion or very highly loaded contacts that were susceptible t adhesive wear and scuffing.

  17. Credit WCT. Photographic copy of photograph, oxidizer and fuel tank ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Credit WCT. Photographic copy of photograph, oxidizer and fuel tank assembly for engine tests being raised by crane for permanent installation in Test Stand "D" tower. Each tank held 170 gallons of propellants. (JPL negative 384-2029-B, 7 August 1959) - Jet Propulsion Laboratory Edwards Facility, Test Stand D, Edwards Air Force Base, Boron, Kern County, CA

  18. Oxidation of Fuel Cladding Candidate Materials in Steam Environments at High Temperature and Pressure

    SciTech Connect

    Cheng, Ting; Keiser, James R; Brady, Michael P; Terrani, Kurt A; Pint, Bruce A

    2012-01-01

    Under certain severe accident conditions, the fuel rods of nuclear power plants are exposed to high temperature/pressure steam environments in which the Zr alloy cladding is rapidly oxidized. As alternative claddings, the oxidation resistances of SiC-based materials and stainless steels with high Cr and/or Al additions have been examined from 800-1200 C in high-pressure steam environments. Very low reaction kinetics were observed with alumina-forming FeCrAl alloys at 1200 C while Fe-Cr alloys with only 15-20% Cr were rapidly attacked.

  19. Oxidation of fuel cladding candidate materials in steam environments at high temperature and pressure

    NASA Astrophysics Data System (ADS)

    Cheng, Ting; Keiser, James R.; Brady, Michael P.; Terrani, Kurt A.; Pint, Bruce A.

    2012-08-01

    Under certain severe accident conditions, the fuel rods of nuclear power plants are exposed to high temperature/pressure steam environments in which the Zr alloy cladding is rapidly oxidized. As alternative claddings, the oxidation resistances of SiC-based materials and stainless steels with high Cr and/or Al additions have been examined from 800-1200 °C in high-pressure steam environments. Very low reaction kinetics were observed with alumina-forming FeCrAl alloys at 1200 °C while Fe-Cr alloys with only 15-20% Cr were rapidly attacked.

  20. Fuel Plume Image Mixing Analysis Formulation With Proper Treatment of Non-Constant Velocity Flowfields

    NASA Technical Reports Server (NTRS)

    Mekkes, Gregory L.

    2000-01-01

    A previously developed technique allows an estimate of integral mixing to be obtained from an image of laser scattered light from particle seeded fuel in the hypervelocity flow through a scramjet combustor. This previous mixing analysis formulation contains an assumption of a constant velocity flowfield across the plane of the fuel plume image. For high-speed scramjet combustors, the velocity flowfield is quite uniform and an assumption of constant velocity works well. Applying this same mixing analysis technique to fuel plume images obtained from a mid-speed scramjet combustor makes it desirable to remove the constant velocity assumption. This is due to the non-uniform velocity flowfields present in mid-speed scramjet combustors. A new formulation of the mixing analysis methodology is developed and presented so that the technique can be applied to a mid-speed scramjet combustor without the need to assume a constant velocity flowfield.

  1. ENERGY PRODUCTION AND POLLUTION PREVENTION AT SEWAGE TREATMENT PLANTS USING FUEL CELL POWER PLANTS

    EPA Science Inventory

    The paper discusses energy production and pollution prevention at sewage treatment plants using fuel cell power plants. Anaerobic digester gas (ADG) is produced at waste water treatment plants during the anaerobic treatment of sewage to reduce solids. The major constituents are...

  2. Solid Oxide Fuel Cell Hybrid System for Distributed Power Generation

    SciTech Connect

    Faress Rahman; Nguyen Minh

    2004-01-04

    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.

  3. Solid Oxide Fuel Cell Hybrid System for Distributed Power Generation

    SciTech Connect

    Nguyen Minh

    2004-07-04

    This report summarizes the work performed by Hybrid Power Generation Systems, LLC (HPGS) during the January to June 2004 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.

  4. Electrocatalyst for alcohol oxidation at fuel cell anodes

    DOEpatents

    Adzic, Radoslav; Kowal, Andrzej

    2011-11-02

    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.

  5. Nanoparticle scaffolds for syngas-fed solid oxide fuel cells

    SciTech Connect

    Boldrin, Paul; Ruiz-Trejo, Enrique; Yu, Jingwen; Gruar, Robert I.; Tighe, Christopher J.; Chang, Kee-Chul; Ilavsky, Jan; Darr, Jawwad A.; Brandon, Nigel

    2014-12-17

    Incorporation of nanoparticles into devices such as solid oxide fuel cells (SOFCs) may provide benefits such as higher surface areas or finer control over microstructure. However, their use with traditional fabrication techniques such as screen-printing is problematic. Here, we show that mixing larger commercial particles with nanoparticles allows traditional ink formulation and screen-printing to be used while still providing benefits of nanoparticles such as increased porosity and lower sintering temperatures. SOFC anodes were produced by impregnating ceria–gadolinia (CGO) scaffolds with nickel nitrate solution. The scaffolds were produced from inks containing a mixture of hydrothermally-synthesised nanoparticle CGO, commercial CGO and polymeric pore formers. The scaffolds were heat-treated at either 1000 or 1300 °C, and were mechanically stable. In situ ultra-small X-ray scattering (USAXS) shows that the nanoparticles begin sintering around 900–1000 °C. Analysis by USAXS and scanning electron microscopy (SEM) revealed that the low temperature heat-treated scaffolds possessed higher porosity. Impregnated scaffolds were used to produce symmetrical cells, with the lower temperature heat-treated scaffolds showing improved gas diffusion, but poorer charge transfer. Using these scaffolds, lower temperature heat-treated cells of Ni–CGO/200 μm YSZ/CGO-LSCF performed better at 700 °C (and below) in hydrogen, and performed better at all temperatures using syngas, with power densities of up to 0.15 W cm-2 at 800 °C. This approach has the potential to allow the use of a wider range of materials and finer control over microstructure.

  6. Nanoparticle scaffolds for syngas-fed solid oxide fuel cells

    DOE PAGES

    Boldrin, Paul; Ruiz-Trejo, Enrique; Yu, Jingwen; Gruar, Robert I.; Tighe, Christopher J.; Chang, Kee-Chul; Ilavsky, Jan; Darr, Jawwad A.; Brandon, Nigel

    2014-12-17

    Incorporation of nanoparticles into devices such as solid oxide fuel cells (SOFCs) may provide benefits such as higher surface areas or finer control over microstructure. However, their use with traditional fabrication techniques such as screen-printing is problematic. Here, we show that mixing larger commercial particles with nanoparticles allows traditional ink formulation and screen-printing to be used while still providing benefits of nanoparticles such as increased porosity and lower sintering temperatures. SOFC anodes were produced by impregnating ceria–gadolinia (CGO) scaffolds with nickel nitrate solution. The scaffolds were produced from inks containing a mixture of hydrothermally-synthesised nanoparticle CGO, commercial CGO and polymericmore » pore formers. The scaffolds were heat-treated at either 1000 or 1300 °C, and were mechanically stable. In situ ultra-small X-ray scattering (USAXS) shows that the nanoparticles begin sintering around 900–1000 °C. Analysis by USAXS and scanning electron microscopy (SEM) revealed that the low temperature heat-treated scaffolds possessed higher porosity. Impregnated scaffolds were used to produce symmetrical cells, with the lower temperature heat-treated scaffolds showing improved gas diffusion, but poorer charge transfer. Using these scaffolds, lower temperature heat-treated cells of Ni–CGO/200 μm YSZ/CGO-LSCF performed better at 700 °C (and below) in hydrogen, and performed better at all temperatures using syngas, with power densities of up to 0.15 W cm-2 at 800 °C. This approach has the potential to allow the use of a wider range of materials and finer control over microstructure.« less

  7. Shuttle orbter fuel cell power plant

    NASA Technical Reports Server (NTRS)

    1983-01-01

    This is one of the three fuel cells that make up the generating system which provides electrical power to the space shuttle orbiter. Each unit measures 14 inches (35 centimeters) high, 15 inches (38 centimeters) wide, 40 inches (101 centimeters) long and weighs 200 pounds.

  8. Development of molten carbonate fuel cell power plant technology

    NASA Astrophysics Data System (ADS)

    Bushnell, C. L.; Davis, C. L.; Dayton, J. E.; Johnson, C. K.; Katz, M.; Krasij, M.; Kunz, H. R.; Maricle, D. L.; Meyer, A. P.; Pivar, J. C.

    1984-09-01

    A prototype molten carbonate fuel cell stack which meets the requirements of a 1990's-competitive, coal-fired electrical utility central station, or industrial cogeneration power plant was developed. Compressive creep testing of the present anode is continuedl the samples and support the earlier data showing improved creep resistance. Testing to define the operating limits that are suitable for extending the life of nickel oxide cathodes to an acceptable level is continuing. The mechanical characteristics of several one-piece cathode current collector candidates are measured for suitability. Metallographic evaluation of stack separators was initiated. Posttest characterization of surface treated INCO 825 was completed, retort corrosion testing of this material is continuing, potentiostatic immersion testing of alternative single piece cathode current collector materials is initiated. The 20-cell Stack No. 3 progressed from completion and delivery of the Test Plan through Design Review, assembly, and initial heat-up for the start of testing. Manufacture of separator plates for the upcoming 20-cell Stack No. 4 has begun. The primary objective of this follow-on test is stack cost reduction.

  9. A technique to measure fuel oil viscosity in a fuel power plant.

    PubMed

    Delgadillo, Miguel Angel; Ibargüengoytia, Pablo H; García, Uriel A

    2016-01-01

    The viscosity measurement and control of fuel oil in power plants is very important for a proper combustion. However, the conventional viscometers are only reliable for a short period of time. This paper proposes an on-line analytic viscosity evaluation based on energy balance applied to a piece of tube entering the fuel oil main heater and a new control strategy for temperature control. This analytic evaluation utilizes a set of temperature versus viscosity graphs were defined during years of analysis of fuel oil in Mexican power plants. Also the temperature set-point for the fuel oil main heater output is obtained by interpolating in the corresponding graph. Validation tests of the proposed analytic equations were carried out in the Tuxpan power plant in Veracruz, Mexico.

  10. Ion beam mixed oxidation protective coating on Zry-4 cladding

    NASA Astrophysics Data System (ADS)

    Park, Jae-Won; Kim, Jae-Un; Park, Jeong-Yong

    2016-06-01

    In this study, SiC was coated on the surface of Zry-4 cladding to improve the oxidation protectiveness. In the coating of SiC onto Zry-4, the prime concern was adhesion at an elevated temperature. Here, a 70 keV N ion beam was irradiated onto a SiC coating layer of ∼100 nm in thickness; this was deposited via the e-beam evaporation method. Additional coating to a target thickness was then carried out. The films deposited without ion-beam mixing (IBM) often peeled-off at an elevated temperature, while the IBM SiC film always adhered to Zry-4, even after heating to ∼1000 °C; at such a temperature, however, cracks formed in the film. X-ray photoelectron spectroscopy (XPS) analysis showed that the deposited SiC film contained about 20 at.% of O, while after annealing in air, 76 at.% of O was found on the surface layer. This implied that both the surface of SiC film and Zry-4 in the crack lines were oxidized. Comparing the Zr3d peak positions across the interface, a shift of binding energy by ∼1 eV was detected, representing that, in view of favorable thermodynamics, SiC/Zry-4 seems to be an acceptable system to apply IBM. To heal the crack, the process of IBM for a 1 μm thick coating and annealing was repeated. High-resolution field emission secondary electron microscopy (FE-SEM) showed that the crack lines, the main places at which oxidation occurred, were gradually covered as the process was repeated, ensuring enhanced oxidation protectiveness.

  11. Nitric oxide and plant iron homeostasis.

    PubMed

    Buet, Agustina; Simontacchi, Marcela

    2015-03-01

    Like all living organisms, plants demand iron (Fe) for important biochemical and metabolic processes. Internal imbalances, as a consequence of insufficient or excess Fe in the environment, lead to growth restriction and affect crop yield. Knowledge of signals and factors affecting each step in Fe uptake from the soil and distribution (long-distance transport, remobilization from old to young leaves, and storage in seeds) is necessary to improve our understanding of plant mineral nutrition. In this context, the role of nitric oxide (NO) is discussed as a key player in maintaining Fe homeostasis through its cross talk with hormones, ferritin, and frataxin and the ability to form nitrosyl-iron complexes. PMID:25612116

  12. Solid oxide fuel cell with single material for electrodes and interconnect

    DOEpatents

    McPheeters, Charles C.; Nelson, Paul A.; Dees, Dennis W.

    1994-01-01

    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.

  13. Integrated Fuel Injection and Mixing System with Impingement Cooling Face

    NASA Technical Reports Server (NTRS)

    Mansour, Adel B. (Inventor); Harvey, Rex J. (Inventor); Tacina, Robert R. (Inventor); Laing, Peter (Inventor)

    2003-01-01

    An atomizing injector includes a metering set having a swirl chamber, a spray orifice and one or more feed slots etched in a thin plate. The swirl chamber is etched in a first side of the plate and the spray orifice is etched through a second side to the center of the swirl chamber. Fuel feed slots extend non-radially to the swirl chamber. The injector also includes integral swirler structure. The swirler structure includes a cylindrical air swirler passage, also shaped by etching, through at least one other thin plate. The cylindrical air swirler passage is located in co-axial relation to the spray orifice of the plate of the fuel metering set such that fuel directed through the spray orifice passes through the air swirler passage and swirling air is imparted to the fuel such that the fuel has a swirling component of motion. At least one air feed slot is provided in fluid communication with the air swirler passage and extends in non-radial relation thereto. Air supply passages extend through the plates of the metering set and the swirler structure to feed the air feed slot in each plate of the swirler structure.

  14. Thermal impact of an eccentric annular flow around a mixed-oxide pin - An in-pile observation

    SciTech Connect

    Lee, M.J.; Strain, R.V.; Lambert, J.D.B.; Feldman, E.E. ); Nomura, S. )

    1989-11-01

    In a typical subassembly of a liquid-metal reactor, slightly unsymmetric coolant flow and temperature distribution around fuel pins is common and inevitable. The geometric location away from the subassembly center and the irradiation-induced rod bowing are among the primary reasons for such occurrences. Studies of the hydrodynamics of the skewed coolant distribution and the associated fuel pin heat transfer are extensive in both computer modeling and laboratory experimental work. In-pile verification of the phenomenon, however, has been rare. High temperature in fuel pins and the perturbation from temperature-monitoring devices discourage such an endeavor. Recent evidence of the sensitive response of the fuel-sodium reaction product (FSRP) to its decomposition temperature, however, might make in-pile verification possible. The clearly demarcated interface of the FSRP would serve as an excellent thermal monitor that reveals the temperature contour within the fuel. This finding from the postirradiation examination (PIE) of mixed-oxide (MOX) pins, is one of the spin-offs of the run-beyond-cladding-breach (RBCB) program jointly sponsored by the U.S. Department of Energy and the Power Reactor and Nuclear Fuel Development Corporation of Japan. The FSRP fuel interface is thus a good benchmark for verifying fuel and coolant temperature distributions. The RBCB experiment and the associated analysis are discussed and conclusions are presented.

  15. Ionic conductors for solid oxide fuel cells

    DOEpatents

    Krumpelt, Michael; Bloom, Ira D.; Pullockaran, Jose D.; Myles, Kevin M.

    1993-01-01

    An electrolyte that operates at temperatures ranging from 600.degree. C. to 800.degree. C. is provided. The electrolyte conducts charge ionically as well as electronically. The ionic conductors include molecular framework structures having planes or channels large enough to transport oxides or hydrated protons and having net-positive or net-negative charges. Representative molecular framework structures include substituted aluminum phosphates, orthosilicates, silicoaluminates, cordierites, apatites, sodalites, and hollandites.

  16. Ionic conductors for solid oxide fuel cells

    SciTech Connect

    Krumpelt, M.; Bloom, I.D.; Pullockaran, J.D.; Myles, K.M.

    1991-12-31

    An electrolyte that operates at temperatures ranging from 600{degree}C to 800{degree}C is discussed. The electrolyte conducts charge ionically as well as electronically. The ionic conductors include molecular framework structures having planes or channels large enough to transport oxides or hydrated protons and having net-positive or net-negative charges. Representative molecular framework structures include substituted aluminum phosphates, orthosilicates, silicoaluminates, cordierites, apatites, sodalites, and hollandites.

  17. The thermal conductivity of mixed fuel UxPu1-xO2: molecular dynamics simulations

    SciTech Connect

    Liu, Xiang-Yang; Cooper, Michael William Donald; Stanek, Christopher Richard; Andersson, Anders David Ragnar

    2015-10-16

    Mixed oxides (MOX), in the context of nuclear fuels, are a mixture of the oxides of heavy actinide elements such as uranium, plutonium and thorium. The interest in the UO2-PuO2 system arises from the fact that these oxides are used both in fast breeder reactors (FBRs) as well as in pressurized water reactors (PWRs). The thermal conductivity of UO2 fuel is an important material property that affects fuel performance since it is the key parameter determining the temperature distribution in the fuel, thus governing, e.g., dimensional changes due to thermal expansion, fission gas release rates, etc. For this reason it is important to understand the thermal conductivity of MOX fuel and how it differs from UO2. Here, molecular dynamics (MD) simulations are carried out to determine quantitatively, the effect of mixing on the thermal conductivity of UxPu1-xO2, as a function of PuO2 concentrations, for a range of temperatures, 300 – 1500 K. The results will be used to develop enhanced continuum thermal conductivity models for MARMOT and BISON by INL. These models express the thermal conductivity as a function of microstructure state-variables, thus enabling thermal conductivity models with closer connection to the physical state of the fuel.

  18. Diffusion-controlled creep in mixed-conducting oxides

    SciTech Connect

    Routbort, J.L.; Goretta, K.C.; Cook, R.E.; Wolfenstine, J.; Armstrong, T.R.; Clauss, C.; Dominguez-Rodriguez, A.

    1996-06-01

    Steady-state creep rate of the mixed conducting oxides La{sub 1-x}Sr{sub x}MnO{sub 3} (x=0.1, 0.15, 0.25) and La{sub 0.7}Ca{sub 0.3}MnO{sub 3} has been investigated between 1150 and 1300 C. Creep parameters and TEM indicate that deformation is controlled by lattice diffusion of one of the cations. Dependence of creep rate on Sr concentration, combined with a point-defect model, confirms this hypothesis; however the oxygen partial pressure dependence of creep (from 10{sup -1} to 2x10{sup 4} Pa) cannot be accounted for within the framework of a simple point-defect model.

  19. National economic implications of substituting plant oils for diesel fuel

    SciTech Connect

    Collins, G.S.; Griffin, R.C.; Lacewell, R.D.

    1982-01-01

    A regional field crop and national livestock econometric model (TECHSIM) was used to examine the impacts of diverting plant oils (cottonseed and soybeans) to use as a diesel fuel replacement. Two scenarios which represented a five and ten percent replacement of agriculture's diesel fuel use by plant oils were simulated. Producers shift into cotton and soybean production and out of corn, small grains and grain sorghum. Significant price shifts were estimated for cottonseed and soybean meal and oil, fed beef, pork and sheep. The annual reduction in social well being was estimated at about $.5 billion and over $1 billion for replacement of 5 and 10 percent, respectively of agricultural's diesel fuel use by plant oils. 2 figures, 4 tables.

  20. Functionally Graded Cathodes for Solid Oxide Fuel Cells

    SciTech Connect

    YongMan Choi; Meilin Liu

    2006-09-30

    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

  1. Planar solid oxide fuel cell with staged indirect-internal air and fuel preheating and reformation

    DOEpatents

    Geisbrecht, Rodney A; Williams, Mark C

    2003-10-21

    A solid oxide fuel cell arrangement and method of use that provides internal preheating of both fuel and air in order to maintain the optimum operating temperature for the production of energy. The internal preheat passes are created by the addition of two plates, one on either side of the bipolar plate, such that these plates create additional passes through the fuel cell. This internal preheat fuel cell configuration and method reduce the requirements for external heat exchanger units and air compressors. Air or fuel may be added to the fuel cell as required to maintain the optimum operating temperature through a cathode control valve or an anode control valve, respectively. A control loop comprises a temperature sensing means within the preheat air and fuel passes, a means to compare the measured temperature to a set point temperature and a determination based on the comparison as to whether the control valves should allow additional air or fuel into the preheat or bypass manifolds of the fuel cell.

  2. Promising alloys for intermediate-temperature solid oxide fuel cell interconnect application

    NASA Astrophysics Data System (ADS)

    Geng, Shujiang; Zhu, Jiahong

    The formation of a low Cr-volatility and electrically conductive oxide outer layer atop an inner chromia layer via thermal oxidation is highly desirable for preventing chromium evaporation from solid oxide fuel cell (SOFC) metallic interconnects at the SOFC operation temperatures. In this paper, a number of ferritic Fe-22Cr alloys with different levels of Mn and Ti as well as a Ni-based alloy Haynes 242 were cyclically oxidized in air at 800 °C for twenty 100-h cycles. No oxide scale spallation was observed during thermal cycling for any of these alloys. A mixed Mn 2O 3/TiO 2 surface layer and/or a (Mn, Cr) 3O 4 spinel outer layer atop a Cr 2O 3 inner layer was formed for the Fe-22Cr series alloys, while an NiO outer layer with a Cr 2O 3 inner layer was developed for Haynes 242 after cyclic oxidation. For the Fe-22Cr series alloys, the effects of Mn and Ti contents as well as alloy purity on the oxidation resistance and scale area specific resistance were evaluated. The performance of the ferritic alloys was compared with that of Haynes 242. The mismatch in thermal expansion coefficient between the different layers in the oxide scale was identified as a potential concern for these otherwise promising alloys.

  3. DOE small scale fuel alcohol plant design

    SciTech Connect

    LaRue, D.M.; Richardson, J.G.

    1980-01-01

    The Department of Energy, in an effort to facilitate the deployment of rural-based ethanol production capability, has undertaken this effort to develop a basic small-scale plant design capable of producing anhydrous ethanol. The design, when completed, will contain all necessary specifications and diagrams sufficient for the construction of a plant. The design concept is modular; that is, sections of the plant can stand alone or be integrated into other designs with comparable throughput rates. The plant design will be easily scaled up or down from the designed flow rate of 25 gallons of ethanol per hour. Conversion factors will be provided with the final design package to explain scale-up and scale-down procedures. The intent of this program is to provide potential small-scale producers with sound information about the size, engineering requirements, costs and level of effort in building such a system.

  4. The mechanism of the oxidation of propene to acrolein over antimony - Tin mixed oxide catalysts

    SciTech Connect

    Ono, Takehiko ); Hillig, K.W. II; Kuczkowski, R.L. )

    1990-05-01

    The oxidation of propenes such as {sup 13}CH{sub 2}{double bond}CH-CH{sub 3}, CH{sub 2}{double bond}CH-CD{sub 3}, cis-CHD{double bond}CD-CH{sub 3}, and CH{sub 2}{double bond}CH-CH{sub 3} was studied over Sb{sub 6}O{sub 13}, SnO{sub 2}, and Sb-Sn mixed oxide catalysts. The results with {sup 13}CH{sub 2}{double bond}CH-CH{sub 3} and CH{sub 2}{double bond}CH-CD{sub 3} were consistent with a {pi}-allyl intermediate. The isotope effect for allylic hydrogen abstraction was 1/0.55 (k{sub H}/k{sub D}) over the Sb-Sn oxide catalysts, indicating that this is the slowest step in the formation of acrolein as with other catalyst systems. The oxidation of CHD{double bond}CH-CH{sub 3} did not exhibit a marked isotope effect for the second hydrogen abstraction. This is inconsistent with a fast {pi}-allyl to {sigma}-allyl equilibration process or the irreversible {pi}-allyl to {sigma}-allyl conversion observed over other metal oxide catalysts. The absence of an isotope effect is similar to oxidations over rhodium. The roles of Sn and Sb ions in the oxidation are also discussed.

  5. Herbivores can select for mixed defensive strategies in plants.

    PubMed

    Carmona, Diego; Fornoni, Juan

    2013-01-01

    Resistance and tolerance are the most important defense mechanisms against herbivores. Initial theoretical studies considered both mechanisms functionally redundant, but more recent empirical studies suggest that these mechanisms may complement each other, favoring the presence of mixed defense patterns. However, the expectation of redundancy between tolerance and resistance remains unsupported. In this study, we tested this assumption following an ecological genetics field experiment in which the presence/absence of two herbivores (Lema daturaphila and Epitrix parvula) of Datura stramonium were manipulated. In each of three treatments, genotypic selection analyses were performed and selection patterns compared. Our results indicated that selection on resistance and tolerance was significantly different between the two folivores. Tolerance and resistance are not redundant defense strategies in D. stramonium but instead functioned as complementary defenses against both beetle species, favoring the evolution of a mixed defense strategy. Although each herbivore was selected for different defense strategies, the observed average tolerance and resistance were closer to the adaptive peak predicted against E. parvula and both beetles together. In our experimental population, natural selection imposed by herbivores can favor the evolution of mixed defense strategies in plants, accounting for the presence of intermediate levels of tolerance and resistance. PMID:23171270

  6. Investigation of the intermediate oxidation regime of Diesel fuel

    SciTech Connect

    Al-Hamamre, Z.; Trimis, D.

    2009-09-15

    A very high temperature fuel-air mixture is necessary for the thermal partial oxidation process of hydrocarbon fuels in order to have a high reaction temperature which accelerate the reaction kinetics. For Diesel fuel and due to the ignition delay time behavior, different oxidation behavior can be realized at different preheating temperatures. In this work, the intermediate oxidation region of Diesel fuel is investigated. By making use of the ignition delay time behavior, an vaporizer like tube reactor is constructed in order to enable a very high preheating temperature without the risk of self-ignition in a time-independent experiment. The oxidation behavior of Diesel fuel in air is investigated numerically and experimentally. In the numerical part, the ignition delay time was estimated using CHEMIKIN tools for different air-fuel mixtures at different temperatures. The evaporation behavior of the Diesel fuel-air mixtures are investigated at relatively high air preheating temperatures ranging from 500 C up to 680 C. The amount of the process air was varied from an air ratio {lambda} = 0.35 to {lambda} = 0.6. The experiments are also performed with N{sub 2} as an evaporation media and compared with those performed with air to detect any temperature increase in the case of Diesel-air mixtures. The amount of heat release in the low chemistry region as well as in the intermediate region is calculated for the case of Diesel/air mixtures. The experiments show that four different oxidation region of Diesel fuel can be distinguished depending on air inlet temperatures and on the air ratio. At a temperature lower than 723 K (450 C), no chemical reaction takes place. The cool flame reactions start at temperatures above 723 K (450 C). However, no stable cool flame can be achieved unless the air preheating temperature reached about 753 K (480 C). The cool flame region is extended up to about 873 K (600 C), at which the intermediate regime started. This regime stabilized to a

  7. Modeling, control and integration of a portable solid oxide fuel cell system

    NASA Astrophysics Data System (ADS)

    Adhikari, Puran

    This thesis presents an innovative method for the modeling, control and integration of a portable hybrid solid oxide fuel cell system. The control and integration of the fuel cell system is important not only for its efficient operation, but also for issues related to safety and reliability. System modeling is needed in order to facilitate the controller design. Mathematical models of the various components of the system are built in the matlab/simulink environment. Dynamic modeling of the fuel cell stack, catalytic partial oxidation (CPOX) reformer, heat exchanger, tail gas combustor and tail gas splitter of the balance of plant system is performed first. Followed by, modeling of the three input DC/DC converter and energy storage devices (battery and supercapacitor). A two-level control approach, higher level and lower level, is adopted in this research. Each of the two major subsystems, balance of plant subsystem and power electronics subsystem, has its own local level controller (called lower level controller) that are designed such that they follow exactly the command reference from a higher level controller. The higher level controller is an intelligent controller that makes decisions about how the lower level or local controllers should perform based on the status of fuel cell, energy storage device and external load demand. Linear analysis has been done for the design and development of the local controllers as appropriate. For the higher level controller, a finite state machine model is developed and implemented using stateflow and fuzzy logic toolboxes of matlab. Simulations are carried out for the integrated system. The simulation results verify that the controllers are robust in performance during the transient condition when the energy storage devices supplement fuel cells. The temperature and flow rates of the fuel and air are controlled as desired. The output from the designed fuel cell system is a regulated DC voltage, which verifies the overall

  8. Nuclear measurements of fuel-shell mix in inertial confinement fusion implosions at OMEGAa)

    NASA Astrophysics Data System (ADS)

    Rygg, J. R.; Frenje, J. A.; Li, C. K.; Séguin, F. H.; Petrasso, R. D.; Delettrez, J. A.; Glebov, V. Yu.; Goncharov, V. N.; Meyerhofer, D. D.; Radha, P. B.; Regan, S. P.; Sangster, T. C.

    2007-05-01

    Direct drive spherical implosions on the OMEGA laser system [T. R. Boehly et al., Opt. Commun. 133, 495 (1997)] have shown that increased capsule convergence results in increased susceptibility to fuel-shell mix. Mix results from saturation of the Rayleigh-Taylor instability, leading to small-scale, turbulent eddies and atomic-level mixing of the high-density compressed shell with hot, low-density fuel from the core. To sensitively probe the extent of mix, nuclear yields were measured from implosions of capsules filled with pure He3. The plastic capsule shell contains a deuterated plastic (CD) layer either on the inner surface or offset from the inner surface by 1μm. Mixing of D from the shell with hot He3 in the core is necessary to produce 14.7MeV DHe3 protons in such capsules. DHe3-proton spectral measurements have been used to constrain the amount of mix at shock time, to demonstrate that some of the fuel mixes with the offset CD layer, and that capsules with a higher initial fill density or thicker shell are less susceptible to the effects of mix.

  9. HIGH ENERGY LIQUID FUELS FROM PLANTS

    SciTech Connect

    Nemethy, E. K.; Otvos, J. W.; Calvin, M.

    1980-10-01

    The heptane extract of Euphorbia lathyris has a low oxygen content and a heat valve of 42 MJ/kg which is comparable to that of crude oil (44 MJ/kg). These qualities indicate a potential for use as fuel or chemical feedstock material. Therefore we have investigated the chemical composition of this fraction in some detail. Since the amoun of the methanol fraction is quite substantial we have also identified the major components of this fraction.

  10. O/M RATIO MEASUREMENT IN PURE AND MIXED OXIDE FULES - WHERE ARE WE NOW?

    SciTech Connect

    J. RUBIN; ET AL

    2000-12-01

    The oxygen-to-metal (O/M) ratio is one of the most critical parameters of nuclear fuel fabrication, and its measurement is closely monitored for manufacturing process control and to ensure the service behavior of the final product. Thermogravimetry is the most widely used method, the procedure for which has remained largely unchanged since its development some thirty years ago. It was not clear to us, however, that this method is still the optimum one in light of advances in instrumentation, and in the current regulatory environment, particularly with regard to waste management and disposal. As part of the MOX fuel fabrication program at Los Alamos, we conducted a comprehensive review of methods for O/M measurements in UO{sub 2}, PuO{sub 2} and mixed oxide fuels for thermal reactors. A concerted effort was made to access information not available in the open literature. We identified approximately thirty five experimental methods that (a) have been developed with the intent of measuring O/M, (b) provided O/M indirectly by suitable reduction of the measured data, or (c) could provide O/M data with suitable data reduction or when combined with other methods. We will discuss the relative strengths and weaknesses of these methods in their application to current routine and small-lot production environment.

  11. Using Coupled Mesoscale Experiments and Simulations to Investigate High Burn-Up Oxide Fuel Thermal Conductivity

    NASA Astrophysics Data System (ADS)

    Teague, Melissa C.; Fromm, Bradley S.; Tonks, Michael R.; Field, David P.

    2014-12-01

    Nuclear energy is a mature technology with a small carbon footprint. However, work is needed to make current reactor technology more accident tolerant and to allow reactor fuel to be burned in a reactor for longer periods of time. Optimizing the reactor fuel performance is essentially a materials science problem. The current understanding of fuel microstructure have been limited by the difficulty in studying the structure and chemistry of irradiated fuel samples at the mesoscale. Here, we take advantage of recent advances in experimental capabilities to characterize the microstructure in 3D of irradiated mixed oxide (MOX) fuel taken from two radial positions in the fuel pellet. We also reconstruct these microstructures using Idaho National Laboratory's MARMOT code and calculate the impact of microstructure heterogeneities on the effective thermal conductivity using mesoscale heat conduction simulations. The thermal conductivities of both samples are higher than the bulk MOX thermal conductivity because of the formation of metallic precipitates and because we do not currently consider phonon scattering due to defects smaller than the experimental resolution. We also used the results to investigate the accuracy of simple thermal conductivity approximations and equations to convert 2D thermal conductivities to 3D. It was found that these approximations struggle to predict the complex thermal transport interactions between metal precipitates and voids.

  12. Compaction Scale Up and Optimization of Cylindrical Fuel Compacts for the Next Generation Nuclear Plant

    SciTech Connect

    Jeffrey J. Einerson; Jeffrey A. Phillips; Eric L. Shaber; Scott E. Niedzialek; W. Clay Richardson; Scott G. Nagley

    2012-10-01

    Multiple process approaches have been used historically to manufacture cylindrical nuclear fuel compacts. Scale-up of fuel compacting was required for the Next Generation Nuclear Plant (NGNP) project to achieve an economically viable automated production process capable of providing a minimum of 10 compacts/minute with high production yields. In addition, the scale-up effort was required to achieve matrix density equivalent to baseline historical production processes, and allow compacting at fuel packing fractions up to 46% by volume. The scale-up approach of jet milling, fluid-bed overcoating, and hot-press compacting adopted in the U.S. Advanced Gas Reactor (AGR) Fuel Development Program involves significant paradigm shifts to capitalize on distinct advantages in simplicity, yield, and elimination of mixed waste. A series of designed experiments have been completed to optimize compaction conditions of time, temperature, and forming pressure using natural uranium oxycarbide (NUCO) fuel. Results from these experiments are included. The scale-up effort is nearing completion with the process installed and operational using nuclear fuel materials. The process is being certified for manufacture of qualification test fuel compacts for the AGR-5/6/7 experiment at the Advanced Test Reactor (ATR) at the Idaho National Laboratory (INL).

  13. Approaches to mitigate metal catalyst deactivation in solid oxide fuel cell (SOFC) fuel electrodes

    NASA Astrophysics Data System (ADS)

    Adijanto, Lawrence

    While Ni/YSZ cermets have been used successfully in SOFCs, they also have several limitations, thus motivating the use of highly conductive ceramics to replace the Ni components in SOFC anodes. Ceramic electrodes are promising for use in SOFC anodes because they are expected to be less susceptible to sintering and coking, be redox stable, and be more tolerant of impurities like sulfur. In this thesis, for catalytic studies, the infiltration procedure has been used to form composites which have greatly simplified the search for the best ceramics for anode applications. In the development of ceramic fuel electrodes for SOFC, high performance can only be achieved when a transition metal catalyst is added. Because of the high operating temperatures, deactivation of the metal catalyst by sintering and/or coking is a severe problem. In this thesis, two approaches aimed at mitigating metal catalyst deactivation which was achieved by: 1) designing a catalyst that is resistant to coking and sintering and 2) developing a new method for catalyst deposition, will be presented. The first approach involved synthesizing a self-regenerating, "smart" catalyst, in which Co, Cu, or Ni were inserted into the B-site of a perovskite oxide under oxidizing conditions and then brought back to the surface under reducing conditions. This restores lost surface area of sintered metal particles through an oxidation/reduction cycle. Results will be shown for each of the metals, as well as for Cu-Co mixed metal systems, which are found to exhibit good tolerance to carbon deposition and interesting catalytic properties. The second strategy involves depositing novel Pd CeO2 core-shell nanostructure catalysts onto a substrate surface which had been chemically modified to anchor the nanoparticles. The catalyst deposited onto the chemically modified, hydrophobic surface is shown to be uniform and well dispersed, and exhibit excellent thermal stability to temperatures as high as 1373 K. Similar metal

  14. Advanced coal gasifier-fuel cell power plant systems design

    NASA Technical Reports Server (NTRS)

    Heller, M. E.

    1983-01-01

    Two advanced, high efficiency coal-fired power plants were designed, one utilizing a phosphoric acid fuel cell and one utilizing a molten carbonate fuel cell. Both incorporate a TRW Catalytic Hydrogen Process gasifier and regenerator. Both plants operate without an oxygen plant and without requiring water feed; they, instead, require makeup dolomite. Neither plant requires a shift converter; neither plant has heat exchangers operating above 1250 F. Both plants have attractive efficiencies and costs. While the molten carbonate version has a higher (52%) efficiency than the phosphoric acid version (48%), it also has a higher ($0.078/kWh versus $0.072/kWh) ten-year levelized cost of electricity. The phosphoric acid fuel cell power plant is probably feasible to build in the near term: questions about the TRW process need to be answered experimentally, such as weather it can operate on caking coals, and how effective the catalyzed carbon-dioxide acceptor will be at pilot scale, both in removing carbon dioxide and in removing sulfur from the gasifier.

  15. Selective extraction of metals from mixed oxide matrixes using choline-based ionic liquids.

    PubMed

    Abbott, Andrew P; Capper, Glen; Davies, David L; Rasheed, Raymond K; Shikotra, Pragna

    2005-09-19

    The solubility of a range of metal oxides in a eutectic mixture of urea/choline chloride is quantified, and it is shown that the dissolved metals can be reclaimed from a mixed metal oxide matrix using electrodeposition. PMID:16156600

  16. Diagnosis of pusher-fuel mix in spherical implosions using x-ray spectroscopy (invited)

    NASA Astrophysics Data System (ADS)

    Keane, C. J.; Cook, R. C.; Dittrich, T. R.; Hammel, B. A.; Levedahl, W. K.; Landen, O. L.; Langer, S.; Munro, D. H.; Scott, H. A.

    1995-01-01

    Of primary concern in next generation inertial confinement fusion (ICF) implosion experiments is Rayleigh-Taylor (RT) instability of the pusher-fuel interface occurring upon acceleration and deceleration of the pusher. This results in mixing of hot fuel with cold pusher material. One method of diagnosing mix in this case is to place spectroscopic dopants both in the capsule fuel region and the innermost region of the capsule wall adjacent to the fuel. As the degree of pusher/fuel mix is increased (typically through placement of controlled perturbations on the outer surface of the capsule) the pusher dopant x-ray emission increases relative to that of the fuel dopant. Experiments of this type using indirectly driven implosions have been carried out on Nova. In this paper we describe some of the important physics issues underlying spectral line formation in these targets and discuss how they are manifested in the modeling and interpretation of experimental data. The importance of radiative transfer as well as high density plasma phenomena such as continuum lowering and Stark broadening is demonstrated. We provide an overview of recent Nova hydrodynamic instability experiments and discuss how the level of instability growth implicit in a given capsule design impacts the diagnosis of mix through x-ray spectroscopy.

  17. Economic analysis of small-scale fuel alcohol plants

    SciTech Connect

    Schafer, J.J. Jr.

    1980-01-01

    To plan Department of Energy support programs, it is essential to understand the fundamental economics of both the large industrial size plants and the small on-farm size alcohol plants. EG and G Idaho, Inc., has designed a 25 gallon per hour anhydrous ethanol plant for the Department of Energy's Alcohol Fuels Office. This is a state-of-the-art reference plant, which will demonstrate the cost and performance of currently available equipment. The objective of this report is to examine the economics of the EG and G small-scale alcohol plant design and to determine the conditions under which a farm plant is a financially sound investment. The reference EG and G Small-Scale Plant is estimated to cost $400,000. Given the baseline conditions defined in this report, it is calculated that this plant will provide an annual after-tax of return on equity of 15%, with alcohol selling at $1.62 per gallon. It is concluded that this plant is an excellent investment in today's market, where 200 proof ethanol sells for between $1.80 and $2.00 per gallon. The baseline conditions which have a significant effect on the economics include plant design parameters, cost estimates, financial assumptions and economic forecasts. Uncertainty associated with operational variables will be eliminated when EG and G's reference plant begins operation in the fall of 1980. Plant operation will verify alcohol yield per bushel of corn, labor costs, maintenance costs, plant availability and by-product value.

  18. Mixed transition-metal oxides: design, synthesis, and energy-related applications.

    PubMed

    Yuan, Changzhou; Wu, Hao Bin; Xie, Yi; Lou, Xiong Wen David

    2014-02-01

    A promising family of mixed transition-metal oxides (MTMOs) (designated as Ax B3-x O4 ; A, B=Co, Ni, Zn, Mn, Fe, etc.) with stoichiometric or even non-stoichiometric compositions, typically in a spinel structure, has recently attracted increasing research interest worldwide. Benefiting from their remarkable electrochemical properties, these MTMOs will play significant roles for low-cost and environmentally friendly energy storage/conversion technologies. In this Review, we summarize recent research advances in the rational design and efficient synthesis of MTMOs with controlled shapes, sizes, compositions, and micro-/nanostructures, along with their applications as electrode materials for lithium-ion batteries and electrochemical capacitors, and efficient electrocatalysts for the oxygen reduction reaction in metal-air batteries and fuel cells. Some future trends and prospects to further develop advanced MTMOs for next-generation electrochemical energy storage/conversion systems are also presented.

  19. Santa Clara County Planar Solid Oxide Fuel Cell Demonstration Project

    SciTech Connect

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

    2009-11-14

    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.

  20. Trash will fuel new Columbus plant

    SciTech Connect

    Not Available

    1981-05-01

    Columbus, Ohio is building a refuse- and coal-fired 90-MW municipal electric plant that will burn 3000 tons of refuse a day. The plant will burn 80% trash and 20% low-sulfur coal (with the option of burning either all coal or all trash) because the 80-20 ratio offers the best balance between boiler corrosion and efficiency. A general obligation bond sale rather than federal or state financing is possible because of the city's good bond rating. The plant will include a fine-shredder, waste treatment facility, and a coal storage area. Pollution control will be handled by six oversized electrostatic precipitators, six mechanical dust collectors, and three 275-foot stacks. (DCK)