The use of metal hydrides in fuel cell applications

Directory of Open Access Journals (Sweden)

Mykhaylo V. Lototskyy

2017-02-01

Full Text Available This paper reviews state-of-the-art developments in hydrogen energy systems which integrate fuel cells with metal hydride-based hydrogen storage. The 187 reference papers included in this review provide an overview of all major publications in the field, as well as recent work by several of the authors of the review. The review contains four parts. The first part gives an overview of the existing types of fuel cells and outlines the potential of using metal hydride stores as a source of hydrogen fuel. The second part of the review considers the suitability and optimisation of different metal hydrides based on their energy efficient thermal integration with fuel cells. The performances of metal hydrides are considered from the viewpoint of the reversible heat driven interaction of the metal hydrides with gaseous H2. Efficiencies of hydrogen and heat exchange in hydrogen stores to control H2 charge/discharge flow rates are the focus of the third section of the review and are considered together with metal hydride – fuel cell system integration issues and the corresponding engineering solutions. Finally, the last section of the review describes specific hydrogen-fuelled systems presented in the available reference data.

Metal Hydrides for Rechargeable Batteries

Energy Technology Data Exchange (ETDEWEB)

Valoeen, Lars Ole

2000-03-01

Rechargeable battery systems are paramount in the power supply of modern electronic and electromechanical equipment. For the time being, the most promising secondary battery systems for the future are the lithium-ion and the nickel metal hydride (NiMH) batteries. In this thesis, metal hydrides and their properties are described with the aim of characterizing and improving those. The thesis has a special focus on the AB{sub 5} type hydrogen storage alloys, where A is a rare earth metal like lanthanum, or more commonly misch metal, which is a mixture of rare earth metals, mainly lanthanum, cerium, neodymium and praseodymium. B is a transition metal, mainly nickel, commonly with additions of aluminium, cobalt, and manganese. The misch metal composition was found to be very important for the geometry of the unit cell in AB{sub 5} type alloys, and consequently the equilibrium pressure of hydrogen in these types of alloys. The A site substitution of lanthanum by misch metal did not decrease the surface catalytic properties of AB{sub 5} type alloys. B-site substitution of nickel with other transition elements, however, substantially reduced the catalytic activity of the alloy. If the internal pressure within the electrochemical test cell was increased using inert argon gas, a considerable increase in the high rate charge/discharge performance of LaNi{sub 5} was observed. An increased internal pressure would enable the utilisation of alloys with a high hydrogen equivalent pressure in batteries. Such alloys often have favourable kinetics and high hydrogen diffusion rates and thus have a potential for improving the high current discharge rates in metal hydride batteries. The kinetic properties of metal hydride electrodes were found to improve throughout their lifetime. The activation properties were found highly dependent on the charge/discharge current. Fewer charge/discharge cycles were needed to activate the electrodes if a small current was used instead of a higher

Vanadium-based alloy hydrides for heat pumps, compressors, and isotope separation

International Nuclear Information System (INIS)

Libowitz, G.G.

1988-01-01

A series of body-centered cubic (b.c.c.) solid solution alloys have been developed which appears to be unusually suitable for several applications involving metal hydrides. It is normally very difficult to induce the body-centered cubic metals, Nb, V, and Ta, to react with hydrogen; in bulk form the reaction will simply not occur at room temperature. Alloys containing Nb exhibited very large hysteresis effects on hydride formation and thus are not suitable for most applications. However, the V-Ti based alloys showed relatively little hysteresis, and because of their unusual thermodynamic properties offer significant advantages for the specific applications discussed below. (orig./HB)

Anodematerials for Metal Hydride Batteries

DEFF Research Database (Denmark)

Jensen, Jens Oluf

1997-01-01

This report describes the work on development of hydride forming alloys for use as electrode materials in metal hydride batteries. The work has primarily been concentrated on calcium based alloys derived from the compound CaNi5. This compound has a higher capacity compared with alloys used in today......’s hydride batteries, but a much poorer stability towards repeated charge/discharge cycling. The aim was to see if the cycleability of CaNi5 could be enhanced enough by modifications to make the compound a suitable electrode material. An alloying method based on mechanical alloying in a planetary ball mill...

Activation and discharge kinetics of metal hydride electrodes

Energy Technology Data Exchange (ETDEWEB)

Johnsen, Stein Egil

2003-07-01

Potential step chronoamperometry and Electrochemical Impedance Spectroscopy (eis) measurements were performed on single metal hydride particles. For the {alpha}-phase, the bulk diffusion coefficient and the absorption/adsorption rate parameters were determined. Materials produced by atomisation, melt spinning and conventional casting were investigated. The melt spun and conventional cast materials were identical and the atomised material similar in composition. The particles from the cast and the melt spun material were shaped like parallelepipeds. A corresponding equation, for this geometry, for diffusion coupled to an absorption/adsorption reaction was developed. It was found that materials produced by melt spinning exhibited lower bulk diffusion (1.7E-14 m2/s) and absorption/adsorption reaction rate (1.0E-8 m/s), compared to materials produced by conventionally casting (1.1E-13 m2/s and 5.5E-8 m/s respectively). In addition, the influence of particle active surface and relative diffusion length were discussed. It was concluded that there are uncertainties connected to these properties, which may explain the large distribution in the kinetic parameters measured on metal hydride particles. Activation of metal hydride forming materials has been studied and an activation procedure, for porous electrodes, was investigated. Cathodic polarisation of the electrode during a hot alkaline surface treatment gave the maximum discharge capacity on the first discharge of the electrode. The studied materials were produced by gas atomisation and the spherical shape was retained during the activation. Both an AB{sub 5} and an AB{sub 2} alloy was successfully activated and discharge rate properties determined. The AB{sub 2} material showed a higher maximum discharge capacity, but poor rate properties, compared to the AB{sub 5} material. Reduction of surface oxides, and at the same time protection against corrosion of active metallic nickel, can explain the satisfying results of

Complex metal hydrides for hydrogen, thermal and electrochemical energy storage

DEFF Research Database (Denmark)

Møller, Kasper T.; Sheppard, Drew; Ravnsbæk, Dorthe B.

2017-01-01

field. This review illustrates that complex metal hydrides may store hydrogen in the solid state, act as novel battery materials, both as electrolytes and electrode materials, or store solar heat in a more efficient manner as compared to traditional heat storage materials. Furthermore, it is highlighted...... how complex metal hydrides may act in an integrated setup with a fuel cell. This review focuses on the unique properties of light element complex metal hydrides mainly based on boron, nitrogen and aluminum, e.g., metal borohydrides and metal alanates. Our hope is that this review can provide new...

Low-Cost Metal Hydride Thermal Energy Storage System for Concentrating Solar Power Systems

Energy Technology Data Exchange (ETDEWEB)

Zidan, Ragaiy [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Hardy, B. J. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Corgnale, C. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Teprovich, J. A. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Ward, P. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Motyka, Ted [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

2016-01-31

The objective of this research was to evaluate and demonstrate a metal hydride-based TES system for use with a CSP system. A unique approach has been applied to this project that combines our modeling experience with the extensive material knowledge and expertise at both SRNL and Curtin University (CU). Because of their high energy capacity and reasonable kinetics many metal hydride systems can be charged rapidly. Metal hydrides for vehicle applications have demonstrated charging rates in minutes and tens of minutes as opposed to hours. This coupled with high heat of reaction allows metal hydride TES systems to produce very high thermal power rates (approx. 1kW per 6-8 kg of material). A major objective of this work is to evaluate some of the new metal hydride materials that have recently become available. A problem with metal hydride TES systems in the past has been selecting a suitable high capacity low temperature metal hydride material to pair with the high temperature material. A unique aspect of metal hydride TES systems is that many of these systems can be located on or near dish/engine collectors due to their high thermal capacity and small size. The primary objective of this work is to develop a high enthalpy metal hydride that is capable of reversibly storing hydrogen at high temperatures (> 650 °C) and that can be paired with a suitable low enthalpy metal hydride with low cost materials. Furthermore, a demonstration of hydrogen cycling between the two hydride beds is desired.

Hydrogen and dihydrogen bonding of transition metal hydrides

Science.gov (United States)

Jacobsen, Heiko

2008-04-01

Intermolecular interactions between a prototypical transition metal hydride WH(CO) 2NO(PH 3) 2 and a small proton donor H 2O have been studied using DFT methodology. The hydride, nitrosyl and carbonyl ligand have been considered as site of protonation. Further, DFT-D calculations in which empirical corrections for the dispersion energy are included, have been carried out. A variety of pure and hybrid density functionals (BP86, PW91, PBE, BLYP, OLYP, B3LYP, B1PW91, PBE0, X3LYP) have been considered, and our calculations indicate the PBE functional and its hybrid variation are well suited for the calculation of transition metal hydride hydrogen and dihydrogen bonding. Dispersive interactions make up for a sizeable portion of the intermolecular interaction, and amount to 20-30% of the bond energy and to 30-40% of the bond enthalpy. An energy decomposition analysis reveals that the H⋯H bond of transition metal hydrides contains both covalent and electrostatic contributions.

Hydrogen and dihydrogen bonding of transition metal hydrides

International Nuclear Information System (INIS)

Jacobsen, Heiko

2008-01-01

Intermolecular interactions between a prototypical transition metal hydride WH(CO) 2 NO(PH 3 ) 2 and a small proton donor H 2 O have been studied using DFT methodology. The hydride, nitrosyl and carbonyl ligand have been considered as site of protonation. Further, DFT-D calculations in which empirical corrections for the dispersion energy are included, have been carried out. A variety of pure and hybrid density functionals (BP86, PW91, PBE, BLYP, OLYP, B3LYP, B1PW91, PBE0, X3LYP) have been considered, and our calculations indicate the PBE functional and its hybrid variation are well suited for the calculation of transition metal hydride hydrogen and dihydrogen bonding. Dispersive interactions make up for a sizeable portion of the intermolecular interaction, and amount to 20-30% of the bond energy and to 30-40% of the bond enthalpy. An energy decomposition analysis reveals that the H...H bond of transition metal hydrides contains both covalent and electrostatic contributions

Influence of uranium hydride oxidation on uranium metal behaviour

International Nuclear Information System (INIS)

Patel, N.; Hambley, D.; Clarke, S.A.; Simpson, K.

2013-01-01

This work addresses concerns that the rapid, exothermic oxidation of active uranium hydride in air could stimulate an exothermic reaction (burning) involving any adjacent uranium metal, so as to increase the potential hazard arising from a hydride reaction. The effect of the thermal reaction of active uranium hydride, especially in contact with uranium metal, does not increase in proportion with hydride mass, particularly when considering large quantities of hydride. Whether uranium metal continues to burn in the long term is a function of the uranium metal and its surroundings. The source of the initial heat input to the uranium, if sufficient to cause ignition, is not important. Sustained burning of uranium requires the rate of heat generation to be sufficient to offset the total rate of heat loss so as to maintain an elevated temperature. For dense uranium, this is very difficult to achieve in naturally occurring circumstances. Areas of the uranium surface can lose heat but not generate heat. Heat can be lost by conduction, through contact with other materials, and by convection and radiation, e.g. from areas where the uranium surface is covered with a layer of oxidised material, such as burned-out hydride or from fuel cladding. These rates of heat loss are highly significant in relation to the rate of heat generation by sustained oxidation of uranium in air. Finite volume modelling has been used to examine the behaviour of a magnesium-clad uranium metal fuel element within a bottle surrounded by other un-bottled fuel elements. In the event that the bottle is breached, suddenly, in air, it can be concluded that the bulk uranium metal oxidation reaction will not reach a self-sustaining level and the mass of uranium oxidised will likely to be small in relation to mass of uranium hydride oxidised. (authors)

Influence of uranium hydride oxidation on uranium metal behaviour

Energy Technology Data Exchange (ETDEWEB)

Patel, N.; Hambley, D. [National Nuclear Laboratory (United Kingdom); Clarke, S.A. [Sellafield Ltd (United Kingdom); Simpson, K.

2013-07-01

This work addresses concerns that the rapid, exothermic oxidation of active uranium hydride in air could stimulate an exothermic reaction (burning) involving any adjacent uranium metal, so as to increase the potential hazard arising from a hydride reaction. The effect of the thermal reaction of active uranium hydride, especially in contact with uranium metal, does not increase in proportion with hydride mass, particularly when considering large quantities of hydride. Whether uranium metal continues to burn in the long term is a function of the uranium metal and its surroundings. The source of the initial heat input to the uranium, if sufficient to cause ignition, is not important. Sustained burning of uranium requires the rate of heat generation to be sufficient to offset the total rate of heat loss so as to maintain an elevated temperature. For dense uranium, this is very difficult to achieve in naturally occurring circumstances. Areas of the uranium surface can lose heat but not generate heat. Heat can be lost by conduction, through contact with other materials, and by convection and radiation, e.g. from areas where the uranium surface is covered with a layer of oxidised material, such as burned-out hydride or from fuel cladding. These rates of heat loss are highly significant in relation to the rate of heat generation by sustained oxidation of uranium in air. Finite volume modelling has been used to examine the behaviour of a magnesium-clad uranium metal fuel element within a bottle surrounded by other un-bottled fuel elements. In the event that the bottle is breached, suddenly, in air, it can be concluded that the bulk uranium metal oxidation reaction will not reach a self-sustaining level and the mass of uranium oxidised will likely to be small in relation to mass of uranium hydride oxidised. (authors)

Research in Nickel/Metal Hydride Batteries 2017

Directory of Open Access Journals (Sweden)

Kwo-Hsiung Young

2018-02-01

Full Text Available Continuing from a special issue in Batteries in 2016, nineteen new papers focusing on recent research activities in the field of nickel/metal hydride (Ni/MH batteries have been selected for the 2017 Special Issue of Ni/MH Batteries. These papers summarize the international joint-efforts in Ni/MH battery research from BASF, Wayne State University, Michigan State University, FDK Corp. (Japan, Institute for Energy Technology (Norway, Central South University (China, University of Science and Technology Beijing (China, Zhengzhou University of Light Industry (China, Inner Mongolia University of Science and Technology (China, Shenzhen Highpower (China, and University of the Witwatersrand (South Africa from 2016–2017 through reviews of AB2 metal hydride alloys, Chinese and EU Patent Applications, as well as descriptions of research results in metal hydride alloys, nickel hydroxide, electrolyte, and new cell type, comparison work, and projections of future works.

The status and immediate problems of the chemistry of transition metal hydrides

International Nuclear Information System (INIS)

Meikheeva, V.I.

1978-01-01

The state of the art and perspectives of the chemistry transition metal hydrides are reviewed, the hydrides being essentially compounds with interstitial hydrogen in the crystal lattice of the metals. The possibilities of hydrogenation of transition metals are considered along with that of compounds of rare earth elements with metals of the iron family. It is shown that the products of hydrogenation of many alloys are unstable and disintegrate forming simpler hydrides. The phase diagram of La-Ni-H system resembles the isotherm of a ternary metal system with the difference that no continuous series of solid solutions is formed. Most hydrogenation products across LaHsub(2-3)-NiH are X-ray amorphous. The nature of hydrogen in hydrides is discussed along with the possibilities of synthesis of new hydrides of transition metals

Method of making alkali metal hydrides

Science.gov (United States)

Pecharsky, Vitalij K.; Gupta, Shalabh; Pruski, Marek; Hlova, Ihor; Castle, Andra

2017-05-30

A method is provided for making alkali metal hydrides by mechanochemically reacting alkali metal and hydrogen gas under mild temperature (e.g room temperature) and hydrogen pressure conditions without the need for catalyst, solvent, and intentional heating or cooling.

Solubility of hydrogen isotopes in stressed hydride-forming metals

International Nuclear Information System (INIS)

Coleman, C.E.; Ambler, J.F.R.

1983-01-01

Components made from hydride-forming metals can be brittle when particles of hydride are present. The solid solubility limit of hydrogen in these metals needs to be known so that fracture resistance can be properly assessed. Stress affects the solubility of hydrogen in metals. As hydrogen dissolves the metal volume increases, an applied hydrostatic tensile stress supplies work to increase the solubility. Precipitation of hydrides increases the volume further. A hydrostatic tensile stress promotes the formation of hydrides and tends to reduce the terminal solubility. For materials containing hydrogen in solution in equilibrium with hydrides, the effect of stress on the terminal solubility is given. Hydrogen migrates up tensile stress gradients because of the effect of stress on the solubility and solubility limit. Consequently, hydrogen concentrates at flaws. When hydrides are present in the metal matrix, those remote from the flaw tip will preferentially dissolve in favor of those precipitated at the flaw. If the stress is large enough, at some critical condition the hydrides at the flaw will crack. This is delayed hydrogen cracking. Notched and fatigue-cracked cantilever beam specimens (6) (38 x 4 x 3 mm) were machined from the circumferential direction of several cold-worked Zr-2.5 at. % Nb pressure tubes. The chemical compositions had the ranges (in atomic %) Nb - 2.5 to 2.7; O - 0.58 to 0.71; H - 0.018 to 0.18. The effect of test temperature is for a specimen containing 0.13 at. % protium and 0.29 at .% deuterium. Between 505 K and 530 K was less than 1 hr, between 530 K and 537 K it increased to 25.8 h, while at 538 K no cracking was observed up to the 54 h

Hydrogen and dihydrogen bonding of transition metal hydrides

Energy Technology Data Exchange (ETDEWEB)

Jacobsen, Heiko [KemKom, Libellenweg 2, 25917 Leck, Nordfriesland (Germany)], E-mail: jacobsen@kemkom.com

2008-04-03

Intermolecular interactions between a prototypical transition metal hydride WH(CO){sub 2}NO(PH{sub 3}){sub 2} and a small proton donor H{sub 2}O have been studied using DFT methodology. The hydride, nitrosyl and carbonyl ligand have been considered as site of protonation. Further, DFT-D calculations in which empirical corrections for the dispersion energy are included, have been carried out. A variety of pure and hybrid density functionals (BP86, PW91, PBE, BLYP, OLYP, B3LYP, B1PW91, PBE0, X3LYP) have been considered, and our calculations indicate the PBE functional and its hybrid variation are well suited for the calculation of transition metal hydride hydrogen and dihydrogen bonding. Dispersive interactions make up for a sizeable portion of the intermolecular interaction, and amount to 20-30% of the bond energy and to 30-40% of the bond enthalpy. An energy decomposition analysis reveals that the H...H bond of transition metal hydrides contains both covalent and electrostatic contributions.

Tritium processing using metal hydrides

International Nuclear Information System (INIS)

Mallett, M.W.

1986-01-01

E.I. duPont de Nemours and Company is commissioned by the US Department of Energy to operate the Savannah River Plant and Laboratory. The primary purpose of the plant is to produce radioactive materials for national defense. In keeping with current technology, new processes for the production of tritium are being developed. Three main objectives of this new technology are to ease the processing of, ease the storage of, and to reduce the operating costs of the tritium production facility. Research has indicated that the use of metal hydrides offers a viable solution towards satisfying these objectives. The Hydrogen and Fuels Technology Division has the responsibility to conduct research in support of the tritium production process. Metal hydride technology and its use in the storage and transportation of hydrogen will be reviewed

Pore-Confined Light Metal Hydrides for Energy Storage and Catalysis

NARCIS (Netherlands)

Bramwell, P.L.|info:eu-repo/dai/nl/371685117

2017-01-01

Light metal hydrides have enjoyed several decades of attention in the field of hydrogen storage, but their applications have recently begun to diversify more and more into the broader field of energy storage. For example, light metal hydrides have shown great promise as battery materials, in sensors

Hydrogen isotope exchange in metal hydride columns

International Nuclear Information System (INIS)

Wiswall, R.; Reilly, J.; Bloch, F.; Wirsing, E.

1977-01-01

Several metal hydrides were shown to act as chromatographic media for hydrogen isotopes. The procedure was to equilibrate a column of hydride with flowing hydrogen, inject a small quantity of tritium tracer, and observe its elution behavior. Characteristic retention times were found. From these and the extent of widening of the tritium band, the heights equivalent to a theoretical plate could be calculated. Values of around 1 cm were obtained. The following are the metals whose hydrides were studied, together with the temperature ranges in which chromatographic behavior was observed: vanadium, 0 to 70 0 C; zirconium, 500 to 600 0 C; LaNi 5 , -78 to +30 0 C; Mg 2 Ni, 300 to 375 0 C; palladium, 0 to 70 0 C. A dual-temperature isotope separation process based on hydride chromatography was demonstrated. In this, a column was caused to cycle between two temperatures while being supplied with a constant stream of tritium-traced hydrogen. Each half-cycle was continued until ''breakthrough,'' i.e., until the tritium concentration in the effluent was the same as that in the feed. Up to that point, the effluent was enriched or depleted in tritium, by up to 20%

Kinetic behaviour of low-Co AB5-type metal hydride electrodes

International Nuclear Information System (INIS)

Tliha, M.; Boussami, S.; Mathlouthi, H.; Lamloumi, J.; Percheron-Guegan, A.

2010-01-01

The kinetic behaviour of the LaNi 3.55 Mn 0.4 Al 0.3 Co 0.4 Fe 0.35 metal hydride, used as a negative electrode in the nickel/metal hydride (Ni/MH) batteries, was investigated using electrochemical impedance spectroscopy (EIS) at different state of charge (SOC). Impedance measurements were performed in the frequency range from 50 kHz to 1 mHz. Electrochemical impedance spectrum of the metal hydride electrode was interpreted by an equivalent circuit including the different electrochemical processes taking place on the interface between the MH electrode and the electrolyte. Electrochemical kinetic parameters such as the charge-transfer resistance R tc , the exchange current density I 0 and the hydrogen diffusion coefficient D H were determined at different state of charge. The results of EIS measurements indicate that the electrochemical reaction activity of the LaNi 3.55 Mn 0.4 Al 0.3 Co 0.4 Fe 0.35 metal hydride electrode was markedly improved with increasing state of charge (SOC). The transformation α-β is probably a limiting step in the mechanisms of hydrogenation of metal hydride electrode.

Hydriding of metallic thorium

International Nuclear Information System (INIS)

Miyake, Masanobu; Katsura, Masahiro; Matsuki, Yuichi; Uno, Masayoshi

1983-01-01

Powdered thorium is usually prepared through a combination of hydriding and dehydriding processes of metallic thorium in massive form, in which the hydriding process consists of two steps: the formation of ThH 2 , and the formation of Th 4 H 15 . However, little has yet been known as to on what stage of hydriding process the pulverization takes place. It is found in the present study that the formation of Th 4 H 15 by the reaction of ThH 2 with H 2 is responsible for pulverization. Temperature of 70 deg C adopted in this work for the reaction of formation Th 4 H 15 seems to be much more effective for production of powdered thorium than 200 - 300 deg C in the literature. The pressure-composition-temperature relationships for Th-H system are determined at 200, 300, 350, and 800 deg C. From these results, a tentative equilibrium phase diagram for the Th-H system is proposed, attention being focused on the two-phase region of ThH 2 and Th 4 H 15 . Pulverization process is discussed in terms of the tentative phase diagram. (author)

Are RENiAl hydrides metallic?

Czech Academy of Sciences Publication Activity Database

Eichinger, K.; Havela, L.; Prokleška, J.; Stelmakhovych, O.; Daniš, S.; Šantavá, Eva; Miliyanchuk, K.

2009-01-01

Roč. 100, č. 9 (2009), s. 1200-1202 ISSN 1862-5282 Grant - others:GA ČR(CZ) GA202/07/0418 Institutional research plan: CEZ:AV0Z10100520 Keywords : rare earth metals * magnetism * hydrides Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 0.862, year: 2009

Evaluation of Neutron shielding efficiency of Metal hydrides

Energy Technology Data Exchange (ETDEWEB)

Jeon, Sang Hwan; Chae, San; Kim, Yong Soo [Hanyang University, Seoul (Korea, Republic of)

2012-05-15

Neutron shielding is achieved of interaction with material by moderation and absorption. Material that contains large amounts hydrogen atoms which are almost same neutron atomic weight is suited for fast neutron shielding material. Therefore, polymers containing high density hydrogen atom are being used for fast neutron shielding. On the other hand, composite materials containing high thermal neutron absorption cross section atom (Li, B, etc) are being used for thermal neutron shielding. However, these materials have low fast neutron absorption cross section. Therefore, these materials are not suited for fast neutron shielding. Hydrogen which has outstanding neutron energy reduction ability has very low thermal neutron absorption cross section, almost cannot be used for thermal neutron shielding. In this case, a large atomic number material (Pb, U, etc.) has been used. Thus, metal hydrides are considered as complement to concrete shielding material. Because metal hydrides contain high hydrogen density and elements with high atomic number. In this research neutron shielding performance and characteristic of nuclear about metal hydrides ((TiH{sub 2}, ZrH{sub 2}, HfH{sub 2}) is evaluated by experiment and MCNPX using {sup 252}Cf neutron source as purpose development shielding material to developed shielding material

Hydrogen storage in metal hydrides and complex hydrides; Wasserstoffspeicherung in Metall- und komplexen Hydriden - Schlussbericht

Energy Technology Data Exchange (ETDEWEB)

Bielmann, M.; Zuettel, A.

2007-07-01

This final report for the Swiss Federal Office of Energy (SFOE), reports on work done in 2007 at the Swiss Federal Laboratories for Materials Science and Technology EMPA on the storage of hydrogen in metal hydrides and complex hydrides. In particular, the use of tetrahydroborates is noted. The potential of this class of materials is stressed. The structures at room-temperature were examined using neutron and X-ray diffraction methods. Thermodynamic methods helped determine the thermodynamic stability of the materials. Also, a complete energy diagram for the materials was developed. The use of silicon oxide to reduce activation energy and its catalytic effects are discussed. The challenges placed by desorption mechanisms are noted. The authors note that reversibility is basically proven.

High-efficiency heat pump technology using metal hydrides (eco-energy city project)

Energy Technology Data Exchange (ETDEWEB)

Morita, Y.; Harada, T.; Niikura, J.; Yamamoto, Y.; Suzuki, J. [Human Environmental Systems Development Center, Matsushita Electric Industrial Co., Ltd., Moriguchi, Osaka (Japan); Gamo, T. [Corporate Environmental Affairs Div., Matsushita Electric Industrial Co., Ltd., Kadoma, Osaka (Japan)

1999-07-01

Metal hybrides are effective materials for utilizing hydrogen as a clean energy medium. That is, when the metal hydrides absorb or desorb the hydrogen, a large heat output of reaction occurs. So, the metal hydrides can be applied to a heat pump. We have researched on a high efficiency heat pump technology using their metal hydrides. In this report, a double effect type metal hydride heat pump configuration is described in which the waste heat of 160 C is recovered in a factory cite and transported to areas far distant from the industrial district. In the heat recovery unit, a low pressure hydrogen is converted into highly effective high pressure hydrogen by applying the metal hydrides. Other metal hydrides perform the parts of heating by absorbing the hydrogen and cooling by desorbing the hydrogen in the heat supply unit. One unit scale of the system is 3 kW class as the sum of heating and cooling. This system using the hydrogen absorbing alloy also has good energy storage characteristics and ambient hydrogen pressure self-safety control ability. Furthermore, this heating and cooling heat supply system is not harmful to the natural environment because it is a chlorofluorocarbon-free, and low noise type system. We have developed in the following element technologies to attain the above purposes, that is development of hydrogen absorbing alloys with high heat outputs and technologies to construct the heat pump system. This study is proceeded at present as one of the programs in New Sunshine Project, which aims for development of ingenious energy utilization technology to achieve reduction of primary energy consumption with keeping cultural and wealthy life and preventing deterioration of global environment. (orig.)

Oxidation of Group 8 transition-Metal Hydrides and Ionic Hydrogenation of Ketones and Aldehydes

Energy Technology Data Exchange (ETDEWEB)

Smith, Kjell-Tore

1996-08-01

Transition-metal hydrides have received considerable attention during the last decades because of their unusual reactivity and their potential as homogeneous catalysts for hydrogenation and other reactions of organic substrates. An important class of catalytic processes where transition-metal hydrides are involved is the homogeneous hydrogenation of alkenes, alkynes, ketones, aldehydes, arenes and nitro compounds. This thesis studies the oxidation of Group 8 transition-metal hydrides and the ionic hydrogenation of ketones and aldehydes.

The effect of compositional changes on the structural and hydrogen storage properties of (La–Ce)Ni5 type intermetallics towards compounds suitable for metal hydride hydrogen compression

International Nuclear Information System (INIS)

Odysseos, M.; De Rango, P.; Christodoulou, C.N.; Hlil, E.K.; Steriotis, T.; Karagiorgis, G.; Charalambopoulou, G.; Papapanagiotou, T.; Ampoumogli, A.; Psycharis, V.; Koultoukis, E.; Fruchart, D.; Stubos, A.

2013-01-01

Graphical abstract: The effect of the partial substitution of La with Ce on the crystal structure and the final hydrogen storage properties of the alloys. Highlights: ► Absorption-based systems exploit the properties of reversible metal hydrides. ► AB5 intermetallics are mostly popular for thermal desorption compressors. ► Investigation of H2 absorption/desorption properties of LaNi5 and its derivatives. ► LaNi5 thermodynamic properties adjustment by partially replacing La with rare earths. -- Abstract: The present work has been aiming at the synthesis and study of a series of La 1−x Ce x Ni 5 (x = 0, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8) alloys in an attempt to investigate possible alterations of the hydrogen absorption/desorption properties The alloys were prepared by induction melting of the constituent elements. The systematic characterization of all new compounds by means of XRD and hydrogen sorption measurements revealed the effect of the partial substitution of La with Ce on the crystal structure and the final hydrogen storage properties of the alloys. Extensive absorption/desorption experiments (Van’t Hoff diagrams) have shown that such alloys can be used to build a metal hydride compressor (MHC), compressing H 2 gas from 0.2 MPa to 4.2 MPa using cold (20 °C) and hot (80 °C) water

Investigation of Lithium Metal Hydride Materials for Mitigation of Deep Space Radiation

Science.gov (United States)

Rojdev, Kristina; Atwell, William

2016-01-01

Radiation exposure to crew, electronics, and non-metallic materials is one of many concerns with long-term, deep space travel. Mitigating this exposure is approached via a multi-faceted methodology focusing on multi-functional materials, vehicle configuration, and operational or mission constraints. In this set of research, we are focusing on new multi-functional materials that may have advantages over traditional shielding materials, such as polyethylene. Metal hydride materials are of particular interest for deep space radiation shielding due to their ability to store hydrogen, a low-Z material known to be an excellent radiation mitigator and a potential fuel source. We have previously investigated 41 different metal hydrides for their radiation mitigation potential. Of these metal hydrides, we found a set of lithium hydrides to be of particular interest due to their excellent shielding of galactic cosmic radiation. Given these results, we will continue our investigation of lithium hydrides by expanding our data set to include dose equivalent and to further understand why these materials outperformed polyethylene in a heavy ion environment. For this study, we used HZETRN 2010, a one-dimensional transport code developed by NASA Langley Research Center, to simulate radiation transport through the lithium hydrides. We focused on the 1977 solar minimum Galactic Cosmic Radiation environment and thicknesses of 1, 5, 10, 20, 30, 50, and 100 g/cm2 to stay consistent with our previous studies. The details of this work and the subsequent results will be discussed in this paper.

Metal Hydride assited contamination on Ru/Si surfaces

NARCIS (Netherlands)

Pachecka, Malgorzata; Lee, Christopher James; Sturm, Jacobus Marinus; Bijkerk, Frederik

2013-01-01

In extreme ultraviolet lithography (EUVL) residual tin, in the form of particles, ions, and atoms, can be deposited on nearby EUV optics. During the EUV pulse, a reactive hydrogen plasma is formed, which may be able to react with metal contaminants, creating volatile and unstable metal hydrides that

Hydrogen generation using silicon nanoparticles and their mixtures with alkali metal hydrides

Science.gov (United States)

Patki, Gauri Dilip

mole of Si. We compare our silicon nanoparticles (˜10nm diameter) with commercial silicon nanopowder (rate upon decreasing the particle size to 10 nm was even greater than would be expected based upon the increase in surface area. While specific surface area increased by a factor of 6 in going from rate increased by a factor of 150. However, in all cases, silicon requires a base (e.g. NaOH, KOH, hydrazine) to catalyze its reaction with water. Metal hydrides are also promising hydrogen storage materials. The optimum metal hydride would possess high hydrogen storage density at moderate temperature and pressure, release hydrogen safely and controllably, and be stable in air. Alkali metal hydrides have high hydrogen storage density, but exhibit high uncontrollable reactivity with water. In an attempt to control this explosive nature while maintaining high storage capacity, we mixed our silicon nanoparticles with the hydrides. This has dual benefits: (1) the hydride- water reaction produces the alkali hydroxide needed for base-catalyzed silicon oxidation, and (2) dilution with 10nm coating by, the silicon may temper the reactivity of the hydride, making the process more controllable. Initially, we analyzed hydrolysis of pure alkali metal hydrides and alkaline earth metal hydrides. Lithium hydride has particularly high hydrogen gravimetric density, along with faster reaction kinetics than sodium hydride or magnesium hydride. On analysis of hydrogen production we found higher hydrogen yield from the silicon nanoparticle—metal hydride mixture than from pure hydride hydrolysis. The silicon-hydride mixtures using our 10nm silicon nanoparticles produced high hydrogen yield, exceeding the theoretical yield. Some evidence of slowing of the hydride reaction rate upon addition of silicon nanoparticles was observed.

Hydrogen metal hydride storage with integrated catalytic recombiner for mobile application

Energy Technology Data Exchange (ETDEWEB)

Marinescu-Pasoi, L.; Behrens, U.; Langer, G.; Gramatte, W.; Rastogi, A.K.; Schmitt, R.E. (Battelle-Institut e.V., Frankfurt am Main (DE). Dept. of Energy Technology)

1991-01-01

A novel, thermodynamically efficient device is under development at Battelle in Frankfurt, by which the range of hydrogen-driven cars with a metal hydride tank might be roughly doubled. The device makes use of the properties of metal hydrides, combined with catalytic combustion. Its development is funded by the Hessian Ministry of Economic Affairs and Technology; it is to be completed by the end of 1990. High-temperature hydrides (HTH) have about three times the storage capacity of low temperature hydrides (LTH), but require relatively large amounts of heat at high temperatures to release the hydrogen. The exhaust heat from combustion-engine-driven vehicles is insufficient for this, and vehicles with electric (fuel cell) drive produce practically no exhaust heat at all. The Battelle-developed device is a combination of an HTH storage cell, an LTH storage cell and a catalyst. (author).

Reactivity patterns of transition metal hydrides and alkyls

International Nuclear Information System (INIS)

Jones, W.D. II.

1979-05-01

The complex PPN + CpV(CO) 3 H - (Cp=eta 5 -C 5 H 5 and PPN = (Ph 3 P) 2 ) was prepared in 70% yield and its physical properties and chemical reactions investigated. PPN + CpV(CO) 3 H - reacts with a wide range of organic halides. The organometallic products of these reactions are the vanadium halides PPN + [CpV(C) 3 X] - and in some cases the binuclear bridging hydride PPN + [CpV(CO) 3 ] 2 H - . The borohydride salt PPN + [CpV(CO) 3 BH 4 ] - has also been prepared. The reaction between CpV(CO) 3 H - and organic halides was investigated and compared with halide reductions carried out using tri-n-butyltin hydride. Results demonstrate that in almost all cases, the reduction reaction proceeds via free radical intermediates which are generated in a chain process, and are trapped by hydrogen transfer from CpV(CO) 3 H - . Sodium amalgam reduction of CpRh(CO) 2 or a mixture of CpRh(CO) 2 and CpCo(CO) 2 affords two new anions, PPN + [Cp 2 Rh 3 (CO) 4 ] - and PPN + [Cp 2 RhCo(CO) 2 ] - . CpMo(CO) 3 H reacts with CpMo(CO) 3 R (R=CH 3 ,C 2 H 5 , CH 2 C 6 H 5 ) at 25 to 50 0 C to produce aldehyde RCHO and the dimers [CpMo(CO) 3 ] 2 and [CpMo(CO) 2 ] 2 . In general, CpV(CO) 3 H - appears to transfer a hydrogen atom to the metal radical anion formed in an electron transfer process, whereas CpMo(CO) 3 H transfers hydride in a 2-electron process to a vacant coordination site. The chemical consequences are that CpV(CO) 3 H - generally reacts with metal alkyls to give alkanes via intermediate alkyl hydride species whereas CpMo(CO) 3 H reacts with metal alkyls to produce aldehyde, via an intermediate acyl hydride species

NATO Advanced Study Institute on Metal Hydrides

CERN Document Server

1981-01-01

In the last five years, the study of metal hydrides has ex­ panded enormously due to the potential technological importance of this class of materials in hydrogen based energy conversion schemes. The scope of this activity has been worldwide among the industrially advanced nations. There has been a consensus among researchers in both fundamental and applied areas that a more basic understanding of the properties of metal/hydrogen syster;,s is required in order to provide a rational basis for the selection of materials for specific applications. The current worldwide need for and interest in research in metal hydrides indicated the timeliness of an Advanced Study Insti­ tute to provide an in-depth view of the field for those active in its various aspects. The inclusion of speakers from non-NATO coun­ tries provided the opportunity for cross-fertilization of ideas for future research. While the emphasis of the Institute was on basic properties, there was a conscious effort to stimulate interest in the applic...

Proton location in metal hydrides using electron spin resonance

International Nuclear Information System (INIS)

Venturini, E.L.

1979-01-01

Electron spin resonance (ESR) of dilute paramagnetic ions establishes the site symmetry of these ions. In the case of metal hydrides the site symmetry is determined by the number and location of neighboring protons. Typical ESR spectra for trivalent erbium in scandium and yttrium hydrides are presented and analyzed, and this technique is shown to be a versatile microscopic probe of the location, net charge and occupation probability of nearby protons

Composite hub/metal blade compressor rotor

Science.gov (United States)

Yao, S.

1978-01-01

A low cost compressor rotor was designed and fabricated for a small jet engine. The rotor hub and blade keepers were compression molded with graphite epoxy. Each pair of metallic blades was held in the hub by a keeper. All keepers were locked in the hub with circumferential windings. Feasibility of fabrication was demonstrated in this program.

Complex Metal Hydrides for Hydrogen, Thermal and Electrochemical Energy Storage

DEFF Research Database (Denmark)

Moller, Kasper T.; Sheppard, Drew; Ravnsbaek, Dorthe B.

2017-01-01

Hydrogen has a very diverse chemistry and reacts with most other elements to form compounds, which have fascinating structures, compositions and properties. Complex metal hydrides are a rapidly expanding class of materials, approaching multi-functionality, in particular within the energy storage...... inspiration to solve the great challenge of our time: efficient conversion and large-scale storage of renewable energy....... field. This review illustrates that complex metal hydrides may store hydrogen in the solid state, act as novel battery materials, both as electrolytes and electrode materials, or store solar heat in a more efficient manner as compared to traditional heat storage materials. Furthermore, it is highlighted...

Tritium immobilization and packaging using metal hydrides

International Nuclear Information System (INIS)

Holtslander, W.J.; Yaraskavitch, J.M.

1981-04-01

Tritium recovered from CANDU heavy water reactors will have to be packaged and stored in a safe manner. Tritium will be recovered in the elemental form, T 2 . Metal tritides are effective compounds in which to immobilize the tritium as a stable non-reactive solid with a high tritium capacity. The technology necessary to prepare hydrides of suitable metals, such as titanium and zirconium, have been developed and the properties of the prepared materials evaluated. Conceptual designs of packages for containing metal tritides suitable for transportation and long-term storage have been made and initial testing started. (author)

Complex Metal Hydrides for hydrogen storage and solid-state ion conductors

DEFF Research Database (Denmark)

Payandeh GharibDoust, SeyedHosein

and electricity in batteries. However, both hydrogen and electricity must be stored in a very dense way to be useful, e.g. for mobile applications. Complex metal hydrides have high hydrogen density and have been studied during the past twenty years in hydrogen storage systems. Moreover, they have shown high ionic...... conductivities which promote their application as solid electrolytes in batteries. This dissertation presents the synthesis and characterization of a variety of complex metal hydrides and explores their hydrogen storage properties and ionic conductivity. Five halide free rare earth borohydrides RE(BH4)3, (RE...... = La, Ce, Pr, Nd, Er) have been synthesized, which pave the way for studying the polymorphic transition in these compounds, obtaining new bimetallic borohydrides and designing new reactive hydride composites with improved hydrogen storage capacities. Two novel polymorphs of Pr(BH4)3 are identified...

Effect of electronegativity on the mechanical properties of metal hydrides with a fluorite structure

International Nuclear Information System (INIS)

Ito, Masato; Setoyama, Daigo; Matsunaga, Junji; Muta, Hiroaki; Kurosaki, Ken; Uno, Masayoshi; Yamanaka, Shinsuke

2006-01-01

Bulk titanium, yttrium, and zirconium hydrides, which have the same structure as that of fluorite-type fcc C 1, were produced and their mechanical properties were investigated. With an increase in the hydrogen content, the lattice parameters of titanium and zirconium hydrides increased, whereas those of yttrium hydride decreased. The elastic moduli of titanium and zirconium hydrides decreased by hydrogen addition, whereas those of yttrium hydride increased. There are linear relations between the electronegativities and hydrogen content dependence of the properties. Therefore, the mechanical properties of the metal hydrides are considered to be determined by a common rule based on the electronegativity

The electrochemical impedance of metal hydride electrodes

DEFF Research Database (Denmark)

Valøen, Lars Ole; Lasia, Andrzej; Jensen, Jens Oluf

2002-01-01

The electrochemical impedance responses for different laboratory type metal hydride electrodes were successfully modeled and fitted to experimental data for AB5 type hydrogen storage alloys as well as one MgNi type electrode. The models fitted the experimental data remarkably well. Several AC......, explaining the experimental impedances in a wide frequency range for electrodes of hydride forming materials mixed with copper powder, were obtained. Both charge transfer and spherical diffusion of hydrogen in the particles are important sub processes that govern the total rate of the electrochemical...... hydrogen absorption/desorption reaction. To approximate the experimental data, equations describing the current distribution in porous electrodes were needed. Indications of one or more parallel reduction/oxidation processes competing with the electrochemical hydrogen absorption/desorption reaction were...

Reactivity patterns of transition metal hydrides and alkyls

Energy Technology Data Exchange (ETDEWEB)

Jones, W.D. II

1979-05-01

The complex PPN/sup +/ CpV(CO)/sub 3/H/sup -/ (Cp=eta/sup 5/-C/sub 5/H/sub 5/ and PPN = (Ph/sub 3/P)/sub 2/) was prepared in 70% yield and its physical properties and chemical reactions investigated. PPN/sup +/ CpV(CO)/sub 3/H/sup -/ reacts with a wide range of organic halides. The organometallic products of these reactions are the vanadium halides PPN/sup +/(CpV(C)/sub 3/X)/sup -/ and in some cases the binuclear bridging hydride PPN/sup +/ (CpV(CO)/sub 3/)/sub 2/H/sup -/. The borohydride salt PPN/sup +/(CpV(CO)/sub 3/BH/sub 4/)/sup -/ has also been prepared. The reaction between CpV(CO)/sub 3/H/sup -/ and organic halides was investigated and compared with halide reductions carried out using tri-n-butyltin hydride. Results demonstrate that in almost all cases, the reduction reaction proceeds via free radical intermediates which are generated in a chain process, and are trapped by hydrogen transfer from CpV(CO)/sub 3/H/sup -/. Sodium amalgam reduction of CpRh(CO)/sub 2/ or a mixture of CpRh(CO)/sub 2/ and CpCo(CO)/sub 2/ affords two new anions, PPN/sup +/ (Cp/sub 2/Rh/sub 3/(CO)/sub 4/)/sup -/ and PPN/sup +/(Cp/sub 2/RhCo(CO)/sub 2/)/sup -/. CpMo(CO)/sub 3/H reacts with CpMo(CO)/sub 3/R (R=CH/sub 3/,C/sub 2/H/sub 5/, CH/sub 2/C/sub 6/H/sub 5/) at 25 to 50/sup 0/C to produce aldehyde RCHO and the dimers (CpMo(CO)/sub 3/)/sub 2/ and (CpMo(CO)/sub 2/)/sub 2/. In general, CpV(CO)/sub 3/H/sup -/ appears to transfer a hydrogen atom to the metal radical anion formed in an electron transfer process, whereas CpMo(CO)/sub 3/H transfers hydride in a 2-electron process to a vacant coordination site. The chemical consequences are that CpV(CO)/sub 3/H/sup -/ generally reacts with metal alkyls to give alkanes via intermediate alkyl hydride species whereas CpMo(CO)/sub 3/H reacts with metal alkyls to produce aldehyde, via an intermediate acyl hydride species.

Development of Hydrogen Storage Tank Systems Based on Complex Metal Hydrides

Directory of Open Access Journals (Sweden)

Morten B. Ley

2015-09-01

Full Text Available This review describes recent research in the development of tank systems based on complex metal hydrides for thermolysis and hydrolysis. Commercial applications using complex metal hydrides are limited, especially for thermolysis-based systems where so far only demonstration projects have been performed. Hydrolysis-based systems find their way in space, naval, military and defense applications due to their compatibility with proton exchange membrane (PEM fuel cells. Tank design, modeling, and development for thermolysis and hydrolysis systems as well as commercial applications of hydrolysis systems are described in more detail in this review. For thermolysis, mostly sodium aluminum hydride containing tanks were developed, and only a few examples with nitrides, ammonia borane and alane. For hydrolysis, sodium borohydride was the preferred material whereas ammonia borane found less popularity. Recycling of the sodium borohydride spent fuel remains an important part for their commercial viability.

Development of Hydrogen Storage Tank Systems Based on Complex Metal Hydrides

Science.gov (United States)

Ley, Morten B.; Meggouh, Mariem; Moury, Romain; Peinecke, Kateryna; Felderhoff, Michael

2015-01-01

This review describes recent research in the development of tank systems based on complex metal hydrides for thermolysis and hydrolysis. Commercial applications using complex metal hydrides are limited, especially for thermolysis-based systems where so far only demonstration projects have been performed. Hydrolysis-based systems find their way in space, naval, military and defense applications due to their compatibility with proton exchange membrane (PEM) fuel cells. Tank design, modeling, and development for thermolysis and hydrolysis systems as well as commercial applications of hydrolysis systems are described in more detail in this review. For thermolysis, mostly sodium aluminum hydride containing tanks were developed, and only a few examples with nitrides, ammonia borane and alane. For hydrolysis, sodium borohydride was the preferred material whereas ammonia borane found less popularity. Recycling of the sodium borohydride spent fuel remains an important part for their commercial viability. PMID:28793541

Metal hydrides: an innovative and challenging conversion reaction anode for lithium-ion batteries

Directory of Open Access Journals (Sweden)

Luc Aymard

2015-08-01

Full Text Available The state of the art of conversion reactions of metal hydrides (MH with lithium is presented and discussed in this review with regard to the use of these hydrides as anode materials for lithium-ion batteries. A focus on the gravimetric and volumetric storage capacities for different examples from binary, ternary and complex hydrides is presented, with a comparison between thermodynamic prediction and experimental results. MgH2 constitutes one of the most attractive metal hydrides with a reversible capacity of 1480 mA·h·g−1 at a suitable potential (0.5 V vs Li+/Li0 and the lowest electrode polarization (2, TiH2, complex hydrides Mg2MHx and other Mg-based hydrides. The reversible conversion reaction mechanism of MgH2, which is lithium-controlled, can be extended to others hydrides as: MHx + xLi+ + xe− in equilibrium with M + xLiH. Other reaction paths—involving solid solutions, metastable distorted phases, and phases with low hydrogen content—were recently reported for TiH2 and Mg2FeH6, Mg2CoH5 and Mg2NiH4. The importance of fundamental aspects to overcome technological difficulties is discussed with a focus on conversion reaction limitations in the case of MgH2. The influence of MgH2 particle size, mechanical grinding, hydrogen sorption cycles, grinding with carbon, reactive milling under hydrogen, and metal and catalyst addition to the MgH2/carbon composite on kinetics improvement and reversibility is presented. Drastic technological improvement in order to the enhance conversion process efficiencies is needed for practical applications. The main goals are minimizing the impact of electrode volume variation during lithium extraction and overcoming the poor electronic conductivity of LiH. To use polymer binders to improve the cycle life of the hydride-based electrode and to synthesize nanoscale composite hydride can be helpful to address these drawbacks. The development of high-capacity hydride anodes should be inspired by the emergent

Metal hydrides: an innovative and challenging conversion reaction anode for lithium-ion batteries.

Science.gov (United States)

Aymard, Luc; Oumellal, Yassine; Bonnet, Jean-Pierre

2015-01-01

The state of the art of conversion reactions of metal hydrides (MH) with lithium is presented and discussed in this review with regard to the use of these hydrides as anode materials for lithium-ion batteries. A focus on the gravimetric and volumetric storage capacities for different examples from binary, ternary and complex hydrides is presented, with a comparison between thermodynamic prediction and experimental results. MgH2 constitutes one of the most attractive metal hydrides with a reversible capacity of 1480 mA·h·g(-1) at a suitable potential (0.5 V vs Li(+)/Li(0)) and the lowest electrode polarization (lithium are subsequently detailed for MgH2, TiH2, complex hydrides Mg2MH x and other Mg-based hydrides. The reversible conversion reaction mechanism of MgH2, which is lithium-controlled, can be extended to others hydrides as: MH x + xLi(+) + xe(-) in equilibrium with M + xLiH. Other reaction paths-involving solid solutions, metastable distorted phases, and phases with low hydrogen content-were recently reported for TiH2 and Mg2FeH6, Mg2CoH5 and Mg2NiH4. The importance of fundamental aspects to overcome technological difficulties is discussed with a focus on conversion reaction limitations in the case of MgH2. The influence of MgH2 particle size, mechanical grinding, hydrogen sorption cycles, grinding with carbon, reactive milling under hydrogen, and metal and catalyst addition to the MgH2/carbon composite on kinetics improvement and reversibility is presented. Drastic technological improvement in order to the enhance conversion process efficiencies is needed for practical applications. The main goals are minimizing the impact of electrode volume variation during lithium extraction and overcoming the poor electronic conductivity of LiH. To use polymer binders to improve the cycle life of the hydride-based electrode and to synthesize nanoscale composite hydride can be helpful to address these drawbacks. The development of high-capacity hydride anodes should

Hydrogen Storage using Metal Hydrides in a Stationary Cogeneration System

International Nuclear Information System (INIS)

Botzung, Maxime; Chaudourne, Serge; Perret, Christian; Latroche, Michel; Percheron-Guegan, Annick; Marty Philippe

2006-01-01

In the frame of the development of a hydrogen production and storage unit to supply a 40 kW stationary fuel cell, a metal hydride storage tank was chosen according to its reliability and high energetic efficiency. The study of AB5 compounds led to the development of a composition adapted to the project needs. The absorption/desorption pressures of the hydride at 75 C (2 / 1.85 bar) are the most adapted to the specifications. The reversible storage capacity (0.95 %wt) has been optimized to our work conditions and chemical kinetics is fast. The design of the Combined Heat and Power CHP system requires 5 kg hydrogen storage but in a first phase, only a 0.1 kg prototype has been realised and tested. Rectangular design has been chosen to obtain good compactness with an integrated plate fin type heat exchanger designed to reach high absorption/desorption rates. In this paper, heat and mass transfer characteristics of the Metal Hydride tank (MH tank) during absorption/desorption cycles are given. (authors)

Theoretical study of hydrogen storage in metal hydrides.

Science.gov (United States)

Oliveira, Alyson C M; Pavão, A C

2018-05-04

Adsorption, absorption and desorption energies and other properties of hydrogen storage in palladium and in the metal hydrides AlH 3 , MgH 2 , Mg(BH 4 ) 2 , Mg(BH 4 )(NH 2 ) and LiNH 2 were analyzed. The DFT calculations on cluster models show that, at a low concentration, the hydrogen atom remains adsorbed in a stable state near the palladium surface. By increasing the hydrogen concentration, the tetrahedral and the octahedral sites are sequentially occupied. In the α phase the tetrahedral site releases hydrogen more easily than at the octahedral sites, but the opposite occurs in the β phase. Among the hydrides, Mg(BH 4 ) 2 shows the highest values for both absorption and desorption energies. The absorption energy of LiNH 2 is higher than that of the palladium, but its desorption energy is too high, a recurrent problem of the materials that have been considered for hydrogen storage. The release of hydrogen, however, can be favored by using transition metals in the material structure, as demonstrated here by doping MgH 2 with 3d and 4d-transition metals to reduce the hydrogen atomic charge and the desorption energy.

Hydrogen storage alloys for nickel/metal hydride battery

Energy Technology Data Exchange (ETDEWEB)

Kuriyama, Nobuhiro; Sakai, Tetsuo; Myamura, Hiroshi; Tanaka, Hideaki; Ishikawa, Hiroshi; Uehara, Itsuki [Osaka National Research Inst. (Japan)

1996-06-01

Efforts to improve performance of metal hydride electrodes such as substitution of alloy components, heat treatment, and surface treatment intended to change surface and bulk structure of hydrogen storage alloys, mainly LaNi{sub 5} based alloys, are reviewed. The importance of control of morphology is emphasized. (author)

Minimum Entropy Generation Theorem Investigation and Optimization of Metal Hydride Alloy Hydrogen Storage

Directory of Open Access Journals (Sweden)

Chi-Chang Wang

2014-05-01

Full Text Available The main purpose of this paper is to carry out numerical simulation of the hydrogen storage on exothermic reaction of metal hydride LaNi5 alloy container. In addition to accelerating the reaction speed of the internal metal hydride by internal control tube water-cooled mode, analyze via the application of second law of thermodynamics the principle of entropy generation. Use COMSOL Mutilphysics 4.3 a to engage in finite element method value simulation on two-dimensional axisymmetric model. Also on the premise that the internal control tube parameters the radius ri, the flow rate U meet the metal hydride saturation time, observe the reaction process of two parameters on the tank, entropy distribution and the results of the accumulated entropy. And try to find the internal tube parameter values of the minimum entropy, whose purpose is to be able to identify the reaction process and the reaction results of internal tank’s optimum energy conservation.

Cascades for hydrogen isotope separation using metal hydrides

International Nuclear Information System (INIS)

Hill, F.B.; Grzetic, V.

1982-01-01

Designs are presented for continuous countercurrent hydrogen isotope separation cascades based on the use of metal hydrides. The cascades are made up of pressure swing adsorption (PSA) or temperature swing adsorption (TSA) stages. The designs were evolved from consideration of previously conducted studies of the separation performance of four types of PSA and TSA processes

Cascades for hydrogen isotope separation using metal hydrides

Energy Technology Data Exchange (ETDEWEB)

Hill, F B; Grzetic, V [Brookhaven National Lab., Upton, NY (USA)

1983-02-01

Designs are presented for continuous countercurrent hydrogen isotope separation cascades based on the use of metal hydrides. The cascades are made up of pressure swing adsorption (PSA) or temperature swing adsorption (TSA) stages. The designs were evolved from consideration of previously conducted studies of the separation performance of four types of PSA and TSA processes.

Process for production of a metal hydride

Science.gov (United States)

Allen, Nathan Tait; Butterick, III, Robert; Chin, Arthur Achhing; Millar, Dean Michael; Molzahn, David Craig

2014-08-12

A process for production of a metal hydride compound MH.sub.x, wherein x is one or two and M is an alkali metal, Be or Mg. The process comprises combining a compound of formula (R.sup.1O).sub.xM with aluminum, hydrogen and at least one metal selected from among titanium, zirconium, hafnium, niobium, vanadium, tantalum and iron to produce a compound of formula MH.sub.x. R.sup.1 is phenyl or phenyl substituted by at least one alkyl or alkoxy group. A mole ratio of aluminum to (R.sup.1O).sub.xM is from 0.1:1 to 1:1. The catalyst is present at a level of at least 200 ppm based on weight of aluminum.

Hydrogen storage properties of metallic hydrides

International Nuclear Information System (INIS)

Latroche, M.; Percheron-Guegan, A.

2005-01-01

Nowadays, energy needs are mainly covered by fossil energies leading to pollutant emissions mostly responsible for global warming. Among the different possible solutions for greenhouse effect reduction, hydrogen has been proposed for energy transportation. Indeed, H 2 can be seen as a clean and efficient energy carrier. However, beside the difficulties related to hydrogen production, efficient high capacity storage means are still to be developed. Many metals and alloys are able to store large amounts of hydrogen. This latter solution is of interest in terms of safety, global yield and long term storage. However, to be suitable for applications, such compounds must present high capacity, good reversibility, fast reactivity and sustainability. In this paper, we will review the structural and thermodynamic properties of metallic hydrides. (authors)

Oxidation kinetics of hydride-bearing uranium metal corrosion products

International Nuclear Information System (INIS)

Totemeier, T.C.; Pahl, R.G.; Frank, S.M.

1998-01-01

The oxidation behavior of hydride-bearing uranium metal corrosion products from zero power physics reactor (ZPPR) fuel plates was studied using thermo-gravimetric analysis (TGA) in environments of Ar-4%O 2 , Ar-9%O 2 , and Ar-20%O 2 . Ignition of corrosion product samples from two moderately corroded plates was observed between 125 C and 150 C in all environments. The rate of oxidation above the ignition temperature was found to be dependent only on the net flow rate of oxygen in the reacting gas. Due to the higher net oxygen flow rate, burning rates increased with increasing oxygen concentration. Oxidation rates below the ignition temperature were much slower and decreased with increasing test time. The hydride contents of the TGA samples from the two moderately corroded plates, determined from the total weight gain achieved during burning, were 47-61 wt% and 29-39 wt%. Samples from a lightly corroded plate were not reactive; X-ray diffraction (XRD) confirmed that they contained little hydride. (orig.)

Analysis of Pressure Variations in a Low-Pressure Nickel-Hydrogen Battery- Part 2: Cells with Metal Hydride Storage.

Science.gov (United States)

Purushothaman, B K; Wainright, J S

2012-05-15

A sub-atmospheric pressure nickel hydrogen (Ni-H(2)) battery with metal hydride for hydrogen storage is developed for implantable neuroprosthetic devices. Pressure variations during charge and discharge of the cell are analyzed at different states of charge and are found to follow the desorption curve of the pressure composition isotherm (PCI) of the metal hydride. The measured pressure agreed well with the calculated theoretical pressure based on the PCI and is used to predict the state of charge of the battery. Hydrogen equilibration with the metal hydride during charge/discharge cycling is fast when the pressure is in the range from 8 to 13 psia and slower in the range from 6 to 8 psia. The time constant for the slower hydrogen equilibration, 1.37h, is similar to the time constant for oxygen recombination and therefore pressure changes due to different mechanisms are difficult to estimate. The self-discharge rate of the cell with metal hydride is two times lower in comparison to the cell with gaseous hydrogen storage alone and is a result of the lower pressure in the cell when the metal hydride is used.

Analysis of Pressure Variations in a Low-Pressure Nickel-Hydrogen Battery– Part 2: Cells with Metal Hydride Storage

Science.gov (United States)

Purushothaman, B. K.; Wainright, J. S.

2012-01-01

A sub-atmospheric pressure nickel hydrogen (Ni-H2) battery with metal hydride for hydrogen storage is developed for implantable neuroprosthetic devices. Pressure variations during charge and discharge of the cell are analyzed at different states of charge and are found to follow the desorption curve of the pressure composition isotherm (PCI) of the metal hydride. The measured pressure agreed well with the calculated theoretical pressure based on the PCI and is used to predict the state of charge of the battery. Hydrogen equilibration with the metal hydride during charge/discharge cycling is fast when the pressure is in the range from 8 to 13 psia and slower in the range from 6 to 8 psia. The time constant for the slower hydrogen equilibration, 1.37h, is similar to the time constant for oxygen recombination and therefore pressure changes due to different mechanisms are difficult to estimate. The self-discharge rate of the cell with metal hydride is two times lower in comparison to the cell with gaseous hydrogen storage alone and is a result of the lower pressure in the cell when the metal hydride is used. PMID:22711974

Process of forming a sol-gel/metal hydride composite

Science.gov (United States)

Congdon, James W [Aiken, SC

2009-03-17

An external gelation process is described which produces granules of metal hydride particles contained within a sol-gel matrix. The resulting granules are dimensionally stable and are useful for applications such as hydrogen separation and hydrogen purification. An additional coating technique for strengthening the granules is also provided.

In-bed accountability of tritium in production scale metal hydride storage beds

International Nuclear Information System (INIS)

Klein, J.E.

1995-01-01

An ''in-bed accountability'' (IBA) flowing gas calorimetric measurement method has been developed and implemented to eliminate the need to remove tritium from production scale metal hydride storage beds for inventory measurement purposes. Six-point tritium IBA calibration curves have been completed for two, 390 gram tritium metal hydride storage beds. The calibration curves for the two tritium beds are similar to those obtained from the ''cold'' test program. Tritium inventory errors at the 95 percent confidence level ranged from ± 7.3 to 8.6 grams for the cold test results compared to ± 4.2 to 7.5 grams obtained for the two tritium calibrated beds

Mathematical modeling of the nickel/metal hydride battery system

Energy Technology Data Exchange (ETDEWEB)

Paxton, Blaine Kermit [Univ. of California, Berkeley, CA (United States). Dept. of Chemical Engineering

1995-09-01

A group of compounds referred to as metal hydrides, when used as electrode materials, is a less toxic alternative to the cadmium hydroxide electrode found in nickel/cadmium secondary battery systems. For this and other reasons, the nickel/metal hydride battery system is becoming a popular rechargeable battery for electric vehicle and consumer electronics applications. A model of this battery system is presented. Specifically the metal hydride material, LaNi{sub 5}H{sub 6}, is chosen for investigation due to the wealth of information available in the literature on this compound. The model results are compared to experiments found in the literature. Fundamental analyses as well as engineering optimizations are performed from the results of the battery model. In order to examine diffusion limitations in the nickel oxide electrode, a ``pseudo 2-D model`` is developed. This model allows for the theoretical examination of the effects of a diffusion coefficient that is a function of the state of charge of the active material. It is found using present data from the literature that diffusion in the solid phase is usually not an important limitation in the nickel oxide electrode. This finding is contrary to the conclusions reached by other authors. Although diffusion in the nickel oxide active material is treated rigorously with the pseudo 2-D model, a general methodology is presented for determining the best constant diffusion coefficient to use in a standard one-dimensional battery model. The diffusion coefficients determined by this method are shown to be able to partially capture the behavior that results from a diffusion coefficient that varies with the state of charge of the active material.

Effect of preparation method of metal hydride electrode on efficiency of hydrogen electrosorption process

Energy Technology Data Exchange (ETDEWEB)

Giza, Krystyna [Czestochowa University of Technology (Poland). Faculty of Production Engineering and Materials Technology; Drulis, Henryk [Trzebiatowski Institute of Low Temperatures and Structure Research PAS, Wroclaw (Poland)

2016-02-15

The preparation of negative electrodes for nickel-metal hydride batteries using LaNi{sub 4.3}Co{sub 0.4}Al{sub 0.3} alloy is presented. The constant current discharge technique is employed to determine the discharge capacity, the exchange current density and the hydrogen diffusion coefficient of the studied electrodes. The electrochemical performance of metal hydride electrode is strongly affected by preparation conditions. The results are compared and the advantages and disadvantages of preparation methods of the electrodes are also discussed.

Sorption compressor/mechanical expander hybrid refrigeration

Science.gov (United States)

Jones, J. A.; Britcliffe, M.

1987-01-01

Experience with Deep Space Network (DSN) ground-based cryogenic refrigerators has proved the reliability of the basic two-stage Gifford-McMahon helium refrigerator. A very long life cryogenic refrigeration system appears possible by combining this expansion system or a turbo expansion system with a hydride sorption compressor in place of the usual motor driven piston compressor. To test the feasibility of this system, a commercial Gifford-McMahon refrigerator was tested using hydrogen gas as the working fluid. Although no attempt was made to optimize the system for hydrogen operation, the refrigerator developed 1.3 W at 30 K and 6.6 W at 60 K. The results of the test and of theoretical performances of the hybrid compressor coupled to these expansion systems are presented.

Hydrogen storage material and process using graphite additive with metal-doped complex hydrides

Science.gov (United States)

Zidan, Ragaiy [Aiken, SC; Ritter, James A [Lexington, SC; Ebner, Armin D [Lexington, SC; Wang, Jun [Columbia, SC; Holland, Charles E [Cayce, SC

2008-06-10

A hydrogen storage material having improved hydrogen absorbtion and desorption kinetics is provided by adding graphite to a complex hydride such as a metal-doped alanate, i.e., NaAlH.sub.4. The incorporation of graphite into the complex hydride significantly enhances the rate of hydrogen absorbtion and desorption and lowers the desorption temperature needed to release stored hydrogen.

Topotactic Solid-State Metal Hydride Reductions of Sr2MnO4.

Science.gov (United States)

Hernden, Bradley C; Lussier, Joey A; Bieringer, Mario

2015-05-04

We report novel details regarding the reactivity and mechanism of the solid-state topotactic reduction of Sr2MnO4 using a series of solid-state metal hydrides. Comprehensive details describing the active reducing species are reported and comments on the reductive mechanism are provided, where it is shown that more than one electron is being donated by H(-). Commonly used solid-state hydrides LiH, NaH, and CaH2, were characterized in terms of reducing power. In addition the unexplored solid-state hydrides MgH2, SrH2, and BaH2 are evaluated as potential solid-state reductants and characterized in terms of their reductive reactivities. These 6 group I and II metal hydrides show the following trend in terms of reactivity: MgH2 < SrH2 < LiH ≈ CaH2 ≈ BaH2 < NaH. The order of the reductants are discussed in terms of metal electronegativity and bond strengths. NaH and the novel use of SrH2 allowed for targeted synthesis of reduced Sr2MnO(4-x) (0 ≤ x ≤ 0.37) phases. The enhanced control during synthesis demonstrated by this soft chemistry approach has allowed for a more comprehensive and systematic evaluation of Sr2MnO(4-x) phases than previously reported phases prepared by high temperature methods. Sr2MnO3.63(1) has for the first time been shown to be monoclinic by powder X-ray diffraction and the oxidative monoclinic to tetragonal transition occurs at 450 °C.

Design and integration of a hydrogen storage on metallic hydrides

International Nuclear Information System (INIS)

Botzung, M.

2008-01-01

This work presents a hydrogen storage system using metal hydrides for a Combined Heat and Power (CHP) system. Hydride storage technology has been chosen due to project specifications: high volumetric capacity, low pressures (≤ 3.5 bar) and low temperatures (≤ 75 C: fuel cell temperature). During absorption, heat from hydride generation is dissipated by fluid circulation. An integrated plate-fin type heat exchanger has been designed to obtain good compactness and to reach high absorption/desorption rates. At first, the storage system has been tested in accordance with project specifications (absorption 3.5 bar, desorption 1.5 bar). Then, the hydrogen charge/discharge times have been decreased to reach system limits. System design has been used to simulate thermal and mass comportment of the storage tank. The model is based on the software Fluent. We take in consideration heat and mass transfers in the porous media during absorption/desorption. The hydride thermal and mass behaviour has been integrated in the software. The heat and mass transfers experimentally obtained have been compared to results calculated by the model. The influence of experimental and numerical parameters on the model behaviour has also been explored. (author) [fr

Characterization of the whiskerlike products formed by hydriding magnesium metal powders

DEFF Research Database (Denmark)

Herley, P. J.; Jones, W.; Vigeholm, Bjørn

1985-01-01

The structure of filamentary crystals produced during the hydriding of magnesium powder has been studies in detail. The needles of small dimensions (typically 0.5 μm in diameter) have been identified by electron analytical techniques to be oriented microcrystals of metallic magnesium. Their forma......The structure of filamentary crystals produced during the hydriding of magnesium powder has been studies in detail. The needles of small dimensions (typically 0.5 μm in diameter) have been identified by electron analytical techniques to be oriented microcrystals of metallic magnesium....... Their formation has been ascribed to the melting of localized aluminum impurities within the bulk magnesium to form a liquid eutectic. In the presence of sublimed magnesium vapor and hydrogen (as a carrier gas) a vapor-liquid-solid mechanism operates to produce a rapid unidirectional extension followed...

Oxidation kinetics of hydride-bearing uranium metal corrosion products

Science.gov (United States)

Totemeier, Terry C.; Pahl, Robert G.; Frank, Steven M.

The oxidation behavior of hydride-bearing uranium metal corrosion products from Zero Power Physics Reactor (ZPPR) fuel plates was studied using thermo-gravimetric analysis (TGA) in environments of Ar-4%O 2, Ar-9%O 2, and Ar-20%O 2. Ignition of corrosion product samples from two moderately corroded plates was observed between 125°C and 150°C in all environments. The rate of oxidation above the ignition temperature was found to be dependent only on the net flow rate of oxygen in the reacting gas. Due to the higher net oxygen flow rate, burning rates increased with increasing oxygen concentration. Oxidation rates below the ignition temperature were much slower and decreased with increasing test time. The hydride contents of the TGA samples from the two moderately corroded plates, determined from the total weight gain achieved during burning, were 47-61 wt% and 29-39 wt%. Samples from a lightly corroded plate were not reactive; X-ray diffraction (XRD) confirmed that they contained little hydride.

Microchip power compensated calorimetry applied to metal hydride characterization

Energy Technology Data Exchange (ETDEWEB)

Sepulveda, A.; Lopeandia, A.F.; Domenech-Ferrer, R.; Garcia, G.; Pi, F.; Rodriguez-Viejo, J. [Nanomaterials and Microsystems Group, Physics Department, Universitat Autonoma de Barcelona, 08193 Bellaterra (Spain); Munoz, F.J. [Instituto de Microelectronica de Barcelona, Centro Nacional de Microelectronica, Campus UAB, 08193 Bellaterra (Spain)

2008-06-15

In this work, we show the suitability of the thin film membrane-based calorimetric technique to measure kinetically limited phase transitions such as the dehydrogenation of metallic hydrides. Different compounds such as Mg, Mg/Al and Mg{sub 80}Ti{sub 20} have been deposited over the active area of the microchip by electron beam evaporation. After several hydrogenation treatments at different temperatures to induce the hydride formation, calorimetric measurements on the dehydrogenation process of those thin films, either in vacuum or in air, are performed at a heating rate of 10 C/min. We observe a significant reduction in the onset of dehydrogenation for Mg{sub 80}Ti{sub 20} compared with pure Mg or Mg/Al layers, which confirms the beneficial effect of Ti on dehydrogenation. We also show the suitability of the membrane-based nanocalorimeters to be used in parallel with optical methods. Quantification of the energy released during hydrogen desorption remains elusive due to the semi-insulating to metallic transition of the film which affects the calorimetric trace. (author)

Bed geometries, fueling strategies and optimization of heat exchanger designs in metal hydride storage systems for automotive applications: A review

DEFF Research Database (Denmark)

Mazzucco, Andrea; Dornheim, Martin; Sloth, Michael

2014-01-01

This review presents recent developments for effective heat management systems to be integrated in metal hydride storage tanks, and investigates the performance improvements and limitations of each particular solution. High pressures and high temperatures metal hydrides can lead to different design...... given to metal hydride storage tanks for light duty vehicles, since this application is the most promising one for such storage materials and has been widely studied in the literature. Enhancing cooling/heating during hydrogen uptake and discharge has found to be essential to improve storage systems...

Theoretical study of a novel solar trigeneration system based on metal hydrides

International Nuclear Information System (INIS)

Meng, Xiangyu; Yang, Fusheng; Bao, Zewei; Deng, Jianqiang; Serge, Nyallang N.; Zhang, Zaoxiao

2010-01-01

In order to utilize the low grade heat energy efficiently, the preliminary scheme of a metal hydride based Combined Cooling, Heating and Power (CCHP) system driven by solar energy and industrial waste heat was proposed, in which both refrigeration and power generation are achieved. Following a step-by-step procedure recently developed by the authors, two pairs of metal hydrides were selected for the CCHP system. The working principle of the system was discussed in detail and further design of the configuration for CCHP was conducted. Based on the cycle mentioned above, the models of energy conversion and exergy analysis were set up. The multi-element valued method was used to assess the performance of the CCHP system in a whole sense, thus the analysis of influence factors on the system performance can be carried out. The typical climate conditions of Xi'an in 2005 were taken for discussion, and the results showed that the system performance is mainly affected by the quantity of solar radiation energy. The objective of the system's optimization is to increase the exergy efficiency of the metal hydride heat pump, based on the quantity of solar radiation energy. The comparison with two different traditional types of CCHP systems proved that the novel CCHP system is superior to the traditional CCHP systems concerning the integrated performance.

Develop improved metal hydride technology for the storage of hydrogen. Final technical report

Energy Technology Data Exchange (ETDEWEB)

Sapru, K.

1998-12-04

The overall objective was to develop commercially viable metal hydrides capable of reversibly storing at least 3 wt.% hydrogen for use with PEM fuel cells and hydrogen fueled internal combustion engine (HICE) applications. Such alloys are expected to result in system capacities of greater than 2 wt.%, making metal hydride storage systems (MHSS`s) a practical means of supplying hydrogen for many consumer applications. ECD`s (Energy Conversion Devices, Inc.) past work on sputtered thin films of transition metal-based alloys led to the commercialization of it`s nickel/metal hydride batteries, and similar work on thin film Mg-based alloys demonstrated potential to achieve very high gravimetric and volumetric energy densities approaching 2,500 Wh/Kg and 2,500 Wh/M{sup 3} respectively. Under this 2-year cost shared project with the DOE, the authors have successfully demonstrated the feasibility of scaling up the Mg-based hydrides from thin film to bulk production without substantial loss of storage capacity. ECD made progress in alloy development by means of compositional and process modification. Processes used include Mechanical Alloying, Melt spinning and novel Gas Phase Condensation. It was showed that the same composition when prepared by melt-spinning resulted in a more homogeneous material having a higher PCT plateau pressure as compared to mechanical alloying. It was also shown that mechanically alloyed Mg-Al-Zn results in much higher plateau pressures, which is an important step towards reducing the desorption temperature. While significant progress has been made during the past two years in alloy development and understanding the relationship between composition, structure, morphology, and processing parameters, additional R and D needs to be performed to achieve the goals of this work.

Mathematical model of a NiOOH/metal hydride cell. Final report, September 15, 1993--November 14, 1996

Energy Technology Data Exchange (ETDEWEB)

White, R.E.; Popov, B.N.

1996-12-31

One of the objectives of work on the nickel/metal hydride cell has been to develop a mathematical model of the performance of the cell. This is a summary of work to date and is meant to be a Final Report of the BES project. Mathematical model of the nickel/metal hydride cell depends on the kinetics, thermodynamics, and transport properties of the metal hydride electrode. Consequently, investigations were carried out to determine: (1) the exchange current density and the equilibrium potential as a function of hydrogen content in the electrode; (2) the hydrogen diffusion coefficient in the bulk of the alloy; (3) the hydrogen reaction rate order; (4) the symmetry factor for hydrogen evolution reaction and (5) to determine the reaction mechanisms of the hydrogen charge and discharge processes including overcharge and overdischarge mechanism.

Research in Nickel/Metal Hydride Batteries 2016

Directory of Open Access Journals (Sweden)

Kwo-Hsiung Young

2016-10-01

Full Text Available Nineteen papers focusing on recent research investigations in the field of nickel/metal hydride (Ni/MH batteries have been selected for this Special Issue of Batteries. These papers summarize the joint efforts in Ni/MH battery research from BASF, Wayne State University, the National Institute of Standards and Technology, Michigan State University, and FDK during 2015–2016 through reviews of basic operational concepts, previous academic publications, issued US Patent and filed Japan Patent Applications, descriptions of current research results in advanced components and cell constructions, and projections of future works.

Recovery Of Electrodic Powder From Spent Nickel-Metal Hydride Batteries (NiMH

Directory of Open Access Journals (Sweden)

Shin S.M.

2015-06-01

Full Text Available This study was focused on recycling process newly proposed to recover electrodic powder enriched in nickel (Ni and rare earth elements (La and Ce from spent nickel-metal hydride batteries (NiMH. In addition, this new process was designed to prevent explosion of batteries during thermal treatment under inert atmosphere. Spent nickel metal hydride batteries were heated over range of 300°C to 600°C for 2 hours and each component was completely separated inside reactor after experiment. Electrodic powder was successfully recovered from bulk components containing several pieces of metals through sieving operation. The electrodic powder obtained was examined by X-ray diffraction (XRD and energy dispersive X-ray spectroscopy (EDX and image of the powder was taken by scanning electron microscopy (SEM. It was finally found that nickel and rare earth elements were mainly recovered to about 45 wt.% and 12 wt.% in electrodic powder, respectively.

ACCEPTABILITY ENVELOPE FOR METAL HYDRIDE-BASED HYDROGEN STORAGE SYSTEMS

Energy Technology Data Exchange (ETDEWEB)

Hardy, B.; Corgnale, C.; Tamburello, D.; Garrison, S.; Anton, D.

2011-07-18

The design and evaluation of media based hydrogen storage systems requires the use of detailed numerical models and experimental studies, with significant amount of time and monetary investment. Thus a scoping tool, referred to as the Acceptability Envelope, was developed to screen preliminary candidate media and storage vessel designs, identifying the range of chemical, physical and geometrical parameters for the coupled media and storage vessel system that allow it to meet performance targets. The model which underpins the analysis allows simplifying the storage system, thus resulting in one input-one output scheme, by grouping of selected quantities. Two cases have been analyzed and results are presented here. In the first application the DOE technical targets (Year 2010, Year 2015 and Ultimate) are used to determine the range of parameters required for the metal hydride media and storage vessel. In the second case the most promising metal hydrides available are compared, highlighting the potential of storage systems, utilizing them, to achieve 40% of the 2010 DOE technical target. Results show that systems based on Li-Mg media have the best potential to attain these performance targets.

Neutron diffraction studies of transition metal hydride complexes

International Nuclear Information System (INIS)

Koetzle, T.F.; Bau, R.

1976-01-01

Investigations of H 3 Ta(C 5 H 5 ) 2 (III), HW 2 (CO) 9 (NO) (IV), and HW 2 (CO) 8 (NO) (P(OCH 3 ) 3 ) (V) have been completed. Preliminary results are available for HFeCo 3 (CO) 9 [P(OCH 3 ) 3 ] 3 (VII). This work, together with studies of HMo 2 (C 5 H 5 ) 2 (CO) 4 (P(CH 3 ) 2 ) (VI) and [(C 2 H 5 ) 4 N] + [HCr 2 (CO) 10 ] - carried out at Argonne has led to some general observations on the geometry and the nature of bonding in these compounds. For example, in the structures of IV and V, both of which have bent W--H--W linkages (less than W--H--W in the range 125-130 0 ), there is conclusive evidence for the existence of a closed three-center W--H--W bond with significant metal-metal interaction. Such is the case, because extensions of the axial W--C and W--N bonds trans to the hydride intersect at a point near the center of the W--H--W triangle. The geometry of VI, which also contains a bent M--H--M bond, is consistent with that of IV and V. Bridging M--H bonds in these second- and third-row hydrides range in length from 1.85 to 1.89 A, compared to 1.75 A in the first-row polynuclear complex VII. For metals of corresponding rows, bridging M--H bonds are about 0.1 A longer than terminal bonds, which are classified as single covalent bonds

Thermomechanics of hydrogen storage in metallic hydrides: modeling and analysis

Czech Academy of Sciences Publication Activity Database

Roubíček, Tomáš; Tomassetti, G.

2014-01-01

Roč. 19, č. 7 (2014), s. 2313-2333 ISSN 1531-3492 R&D Projects: GA ČR GA201/09/0917 Institutional support: RVO:61388998 Keywords : metal-hydrid phase transformation * hydrogen diffusion * swelling Subject RIV: BA - General Mathematics Impact factor: 0.768, year: 2014 http://aimsciences.org/journals/pdfs.jsp?paperID=10195&mode=full

Predicted energy densitites for nickel-hydrogen and silver-hydrogen cells embodying metallic hydrides for hydrogen storage

Science.gov (United States)

Easter, R. W.

1974-01-01

Simplified design concepts were used to estimate gravimetric and volumetric energy densities for metal hydrogen battery cells for assessing the characteristics of cells containing metal hydrides as compared to gaseous storage cells, and for comparing nickel cathode and silver cathode systems. The silver cathode was found to yield superior energy densities in all cases considered. The inclusion of hydride forming materials yields cells with very high volumetric energy densities that also retain gravimetric energy densities nearly as high as those of gaseous storage cells.

Interaction of electrons with light metal hydrides in the transmission electron microscope.

Science.gov (United States)

Wang, Yongming; Wakasugi, Takenobu; Isobe, Shigehito; Hashimoto, Naoyuki; Ohnuki, Somei

2014-12-01

Transmission electron microscope (TEM) observation of light metal hydrides is complicated by the instability of these materials under electron irradiation. In this study, the electron kinetic energy dependences of the interactions of incident electrons with lithium, sodium and magnesium hydrides, as well as the constituting element effect on the interactions, were theoretically discussed, and electron irradiation damage to these hydrides was examined using in situ TEM. The results indicate that high incident electron kinetic energy helps alleviate the irradiation damage resulting from inelastic or elastic scattering of the incident electrons in the TEM. Therefore, observations and characterizations of these materials would benefit from increased, instead decreased, TEM operating voltage. © The Author 2014. Published by Oxford University Press on behalf of The Japanese Society of Microscopy. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Performance study of a hydrogen powered metal hydride actuator

International Nuclear Information System (INIS)

Bhuiya, Md Mainul Hossain; Kim, Kwang J

2016-01-01

A thermally driven hydrogen powered actuator integrating metal hydride hydrogen storage reactor, which is compact, noiseless, and able to generate smooth actuation, is presented in this article. To test the plausibility of a thermally driven actuator, a conventional piston type actuator was integrated with LaNi 5 based hydrogen storage system. Copper encapsulation followed by compaction of particles into pellets, were adopted to improve overall thermal conductivity of the reactor. The operation of the actuator was thoroughly investigated for an array of operating temperature ranges. Temperature swing of the hydride reactor triggering smooth and noiseless actuation over several operating temperature ranges were monitored for quantification of actuator efficiency. Overall, the actuator generated smooth and consistent strokes during repeated cycles of operation. The efficiency of the actuator was found to be as high as 13.36% for operating a temperature range of 20 °C–50 °C. Stress–strain characteristics, actuation hysteresis etc were studied experimentally. Comparison of stress–strain characteristics of the proposed actuator with traditional actuators, artificial muscles and so on was made. The study suggests that design modification and use of high pressure hydride may enhance the performance and broaden the application horizon of the proposed actuator in future. (paper)

Sodium-based hydrides for thermal energy applications

Science.gov (United States)

Sheppard, D. A.; Humphries, T. D.; Buckley, C. E.

2016-04-01

Concentrating solar-thermal power (CSP) with thermal energy storage (TES) represents an attractive alternative to conventional fossil fuels for base-load power generation. Sodium alanate (NaAlH4) is a well-known sodium-based complex metal hydride but, more recently, high-temperature sodium-based complex metal hydrides have been considered for TES. This review considers the current state of the art for NaH, NaMgH3- x F x , Na-based transition metal hydrides, NaBH4 and Na3AlH6 for TES and heat pumping applications. These metal hydrides have a number of advantages over other classes of heat storage materials such as high thermal energy storage capacity, low volume, relatively low cost and a wide range of operating temperatures (100 °C to more than 650 °C). Potential safety issues associated with the use of high-temperature sodium-based hydrides are also addressed.

Conference 'Chemistry of hydrides' Proceedings

International Nuclear Information System (INIS)

1991-07-01

This collection of thesis of conference of Chemistry hydrides presents the results of investigations concerning of base questions of chemistry of nonorganic hydrides, including synthesis questions, studying of physical and chemical properties, thermodynamics, analytical chemistry, investigation of structure, equilibriums in the systems of metal-hydrogen, behaviour of nonorganic hydrides in non-water mediums and applying investigations in the chemistry area and technology of nonorganic hydrides

Hydrogen storage and evolution catalysed by metal hydride complexes.

Science.gov (United States)

Fukuzumi, Shunichi; Suenobu, Tomoyoshi

2013-01-07

The storage and evolution of hydrogen are catalysed by appropriate metal hydride complexes. Hydrogenation of carbon dioxide by hydrogen is catalysed by a [C,N] cyclometalated organoiridium complex, [Ir(III)(Cp*)(4-(1H-pyrazol-1-yl-κN(2))benzoic acid-κC(3))(OH(2))](2)SO(4) [Ir-OH(2)](2)SO(4), under atmospheric pressure of H(2) and CO(2) in weakly basic water (pH 7.5) at room temperature. The reverse reaction, i.e., hydrogen evolution from formate, is also catalysed by [Ir-OH(2)](+) in acidic water (pH 2.8) at room temperature. Thus, interconversion between hydrogen and formic acid in water at ambient temperature and pressure has been achieved by using [Ir-OH(2)](+) as an efficient catalyst in both directions depending on pH. The Ir complex [Ir-OH(2)](+) also catalyses regioselective hydrogenation of the oxidised form of β-nicotinamide adenine dinucleotide (NAD(+)) to produce the 1,4-reduced form (NADH) under atmospheric pressure of H(2) at room temperature in weakly basic water. In weakly acidic water, the complex [Ir-OH(2)](+) also catalyses the reverse reaction, i.e., hydrogen evolution from NADH to produce NAD(+) at room temperature. Thus, interconversion between NADH (and H(+)) and NAD(+) (and H(2)) has also been achieved by using [Ir-OH(2)](+) as an efficient catalyst and by changing pH. The iridium hydride complex formed by the reduction of [Ir-OH(2)](+) by H(2) and NADH is responsible for the hydrogen evolution. Photoirradiation (λ > 330 nm) of an aqueous solution of the Ir-hydride complex produced by the reduction of [Ir-OH(2)](+) with alcohols resulted in the quantitative conversion to a unique [C,C] cyclometalated Ir-hydride complex, which can catalyse hydrogen evolution from alcohols in a basic aqueous solution (pH 11.9). The catalytic mechanisms of the hydrogen storage and evolution are discussed by focusing on the reactivity of Ir-hydride complexes.

Manufacture of titanium and zirconium hydrides

International Nuclear Information System (INIS)

Mares, F.; Hanslik, T.

1973-01-01

A method is described of manufacturing titanium and zirconium hydrides by hydrogenation of said metals characterized by the reaction temperature ranging between 250 to 500 degC, hydrogen pressure of 20 to 300 atm and possibly by the presence of a hydride of the respective metal. (V.V.)

Impacts of external convection on release rates in metal hydride storage tanks. Paper no. IGEC-1-080

International Nuclear Information System (INIS)

MacDonald, B.; Rowe, A.; Tomlinson, J.; Ho, J.

2005-01-01

Reversible metal hydrides can be used to store hydrogen at relatively low pressures, with very high volumetric density. The rate hydrogen can be drawn from a given tank is strongly influenced by the rate heat can be transferred to the reaction zone. Because of this, enhancing and controlling heat transfer is a key area of research in the development of metal hydride storage tanks. In this work, the impacts of external convection resistance on hydrogen release rates are examined. A one-dimensional resistive analysis determines the thermal resistances in the system based on one case where no external heat transfer enhancements are used, and a second case where external fins are used. A two-dimensional, transient model, developed in FEMLAB, is used to determine the impact of the external fins on the mass flow rate of hydrogen in more detail. For the particular metal hydride alloy (LaNi 4.8 Sn 0.2 ) and tank geometry studied, it was found that the fins have a large impact on the hydrogen flow rate during the initial stages of desorption. The flow rate with no fins is only 20% of the flow rate with fins for a full tank, 57% when the tank is 33% full, and 74% when the tank is 5% full. As the reaction proceeds, the resistance of the metal hydride alloy within the tank increases and becomes dominant. Therefore, the impact of the fins becomes less significant as the tank empties. (author)

Activated aluminum hydride hydrogen storage compositions and uses thereof

Science.gov (United States)

Sandrock, Gary; Reilly, James; Graetz, Jason; Wegrzyn, James E.

2010-11-23

In one aspect, the invention relates to activated aluminum hydride hydrogen storage compositions containing aluminum hydride in the presence of, or absence of, hydrogen desorption stimulants. The invention particularly relates to such compositions having one or more hydrogen desorption stimulants selected from metal hydrides and metal aluminum hydrides. In another aspect, the invention relates to methods for generating hydrogen from such hydrogen storage compositions.

The Effect of Hydrogen and Hydrides on the Integrity of Zirconium Alloy Components Delayed Hydride Cracking

CERN Document Server

Puls, Manfred P

2012-01-01

By drawing together the current theoretical and experimental understanding of the phenomena of delayed hydride cracking (DHC) in zirconium alloys, The Effect of Hydrogen and Hydrides on the Integrity of Zirconium Alloy Components: Delayed Hydride Cracking provides a detailed explanation focusing on the properties of hydrogen and hydrides in these alloys. Whilst the focus lies on zirconium alloys, the combination of both the empirical and mechanistic approaches creates a solid understanding that can also be applied to other hydride forming metals.   This up-to-date reference focuses on documented research surrounding DHC, including current methodologies for design and assessment of the results of periodic in-service inspections of pressure tubes in nuclear reactors. Emphasis is placed on showing that our understanding of DHC is supported by progress across a broad range of fields. These include hysteresis associated with first-order phase transformations; phase relationships in coherent crystalline metallic...

Hydrogen isotope exchange in a metal hydride tube

Energy Technology Data Exchange (ETDEWEB)

Robinson, David B. [Sandia National Lab. (SNL-CA), Livermore, CA (United States)

2014-09-01

This report describes a model of the displacement of one hydrogen isotope within a metal hydride tube by a different isotope in the gas phase that is blown through the tube. The model incorporates only the most basic parameters to make a clear connection to the theory of open-tube gas chromatography, and to provide a simple description of how the behavior of the system scales with controllable parameters such as gas velocity and tube radius. A single tube can be seen as a building block for more complex architectures that provide higher molar flow rates or other advanced design goals.

OPTIMIZATION OF INTERNAL HEAT EXCHANGERS FOR HYDROGEN STORAGE TANKS UTILIZING METAL HYDRIDES

Energy Technology Data Exchange (ETDEWEB)

Garrison, S.; Tamburello, D.; Hardy, B.; Anton, D.; Gorbounov, M.; Cognale, C.; van Hassel, B.; Mosher, D.

2011-07-14

Two detailed, unit-cell models, a transverse fin design and a longitudinal fin design, of a combined hydride bed and heat exchanger are developed in COMSOL{reg_sign} Multiphysics incorporating and accounting for heat transfer and reaction kinetic limitations. MatLab{reg_sign} scripts for autonomous model generation are developed and incorporated into (1) a grid-based and (2) a systematic optimization routine based on the Nelder-Mead downhill simplex method to determine the geometrical parameters that lead to the optimal structure for each fin design that maximizes the hydrogen stored within the hydride. The optimal designs for both the transverse and longitudinal fin designs point toward closely-spaced, small cooling fluid tubes. Under the hydrogen feed conditions studied (50 bar), a 25 times improvement or better in the hydrogen storage kinetics will be required to simultaneously meet the Department of Energy technical targets for gravimetric capacity and fill time. These models and methodology can be rapidly applied to other hydrogen storage materials, such as other metal hydrides or to cryoadsorbents, in future work.

Electrochemical investigations and characterization of a metal hydride alloy (MmNi3.6Al0.4Co0.7Mn0.3) for nickel metal hydride batteries

International Nuclear Information System (INIS)

Begum, S. Nathira; Muralidharan, V.S.; Basha, C. Ahmed

2009-01-01

The use of new hydrogen absorbing alloys as negative electrodes in rechargeable batteries has allowed the consideration of nickel/metal hydride (Ni/MH) batteries to replace the conventional nickel cadmium alkaline or lead acid batteries. In this study the performance of trisubstituted hydrogen storage alloy (MmNi 3.6 Al 0.4 Co 0.7 Mn 0.3 ) electrodes used as anodes in Ni/MH secondary batteries were evaluated. MH electrodes were prepared and the electrochemical utilization of the active material was investigated. Cyclic voltammetric technique was used to analyze the beneficial effect of the alloy by various substitutions. The electrochemical impedance spectroscopic measurements of the Ni/MH battery were made at various states of depth of discharge. The effect of temperature on specific capacity is studied and specific capacity as a function of discharge current density was also studied and the results were analyzed. The alloy metal hydride electrode was subjected to charge/discharge cycle for more than 200 cycles. The discharge capacities of the alloy remains at 250 mAh/g with a nominal fading in capacity (to the extent of ∼20 mAh/g) on prolonged cycling

Rapid hydrogen charging on metal hydride negative electrode of Fuel Cell/Battery (FCB) systems

Energy Technology Data Exchange (ETDEWEB)

Choi, Bokkyu; Lee, Sunmook; Kawai, Hiroyuki; Fushimi, Chihiro; Tsutsumi, Atsushi [Collaborative Research Center for Energy Engineering, Institute of Industrial Science, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8505 (Japan)

2009-02-15

The characteristics of rapid gaseous H{sub 2} charging/electrochemical discharging of the metal hydride negative electrode were investigated for the application in Fuel Cell/Battery (FCB) systems. They were evaluated with the H{sub 2} gas absorption, followed by the subsequent electrochemical discharging in the electrolyte solution (6M KOH). Then, the cyclability of charge-discharge was also examined. It was observed that more than 70% of the theoretical capacity was charged within 10 min with 0.3 MPa and 0.5 MPa of the initial H{sub 2} pressures. The electrochemical discharge curve showed that more than 86% of the absorbed H{sub 2} was discharged. Furthermore, the cycled charge-discharge process indicated that the H{sub 2} gas charge and electrochemical discharge process is an effective way to rapidly charge and activate the metal hydride without degeneration. (author)

Variations of structure and magnetic properties in UTGe hydrides (T=late transition metal)

Czech Academy of Sciences Publication Activity Database

Adamska, A.M.; Havela, L.; Skourski, Y.; Andreev, Alexander V.

2012-01-01

Roč. 515, FEB (2012), s. 171-179 ISSN 0925-8388 Institutional research plan: CEZ:AV0Z10100520 Keywords : actinide allos and compounds * metal hydrides * crystal structure * magnetic meaurements * high magnetic fields Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 2.390, year: 2012

Application of hydrogen isotopes and metal hydrides in future energy source

Energy Technology Data Exchange (ETDEWEB)

Guoqiang, Jiang [Sichuan Inst. of Materials and Technology, Chengdu, SC (China)

1994-12-01

The probable application of hydrogen isotopes and metal hydrides to future energy source is reviewed. Starting from existing state of China`s energy source, the importance for developing hydrogen energy and fusion energy is explained. It is suggested that the application investigation of hydrogen energy and hydrogen storage materials should be spurred and encouraged; keeping track of the development on tritium technology for fusion reactor is stressed.

Application of hydrogen isotopes and metal hydrides in future energy source

International Nuclear Information System (INIS)

Jiang Guoqiang

1994-12-01

The probable application of hydrogen isotopes and metal hydrides to future energy source is reviewed. Starting from existing state of China's energy source, the importance for developing hydrogen energy and fusion energy is explained. It is suggested that the application investigation of hydrogen energy and hydrogen storage materials should be spurred and encouraged; keeping track of the development on tritium technology for fusion reactor is stressed

Modeling of hydrogen isotopes separation in a metal hydride bed

International Nuclear Information System (INIS)

Charton, S.; Corriou, J.P.; Schweich, D.

1999-01-01

A predictive model for hydrogen isotopes separation in a non-isothermal bed of unsupported palladium hydride particles is derived. It accounts for the non-linear adsorption-dissociation equilibrium, hydrodynamic dispersion, pressure drop, mass transfer kinetics, heat of sorption and heat losses at the bed wall. Using parameters from the literature or estimated with classical correlations, the model gives simulated curves in agreement with previously published experiments without any parameter fit. The non-isothermal behavior is shown to be responsible for drastic changes of the mass transfer rate which is controlled by diffusion in the solid-phase lattice. For a feed at 300 K and atmospheric pressure, the endothermic hydride-to-deuteride exchange is kinetically controlled, whereas the reverse exothermic exchange is nearly at equilibrium. Finally, a simple and efficient thermodynamic model for the dissociative equilibrium between a metal and a diatomic gas is proposed. (Copyright (c) 1999 Elsevier Science B.V., Amsterdam. All rights reserved.)

Hydrogen Storage Engineering Center of Excellence Metal Hydride Final Report

Energy Technology Data Exchange (ETDEWEB)

Motyka, T. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

2014-05-31

The Hydrogen Storage Engineering Center of Excellence (HSECoE) was established in 2009 by the U.S. Department of Energy (DOE) to advance the development of materials-based hydrogen storage systems for hydrogen-fueled light-duty vehicles. The overall objective of the HSECoE is to develop complete, integrated system concepts that utilize reversible metal hydrides, adsorbents, and chemical hydrogen storage materials through the use of advanced engineering concepts and designs that can simultaneously meet or exceed all the DOE targets. This report describes the activities and accomplishments during Phase 1 of the reversible metal hydride portion of the HSECoE, which lasted 30 months from February 2009 to August 2011. A complete list of all the HSECoE partners can be found later in this report but for the reversible metal hydride portion of the HSECoE work the major contributing organizations to this effort were the United Technology Research Center (UTRC), General Motors (GM), Pacific Northwest National Laboratory (PNNL), the National Renewable Energy Laboratory (NREL) and the Savannah River National Laboratory (SRNL). Specific individuals from these and other institutions that supported this effort and the writing of this report are included in the list of contributors and in the acknowledgement sections of this report. The efforts of the HSECoE are organized into three phases each approximately 2 years in duration. In Phase I, comprehensive system engineering analyses and assessments were made of the three classes of storage media that included development of system level transport and thermal models of alternative conceptual storage configurations to permit detailed comparisons against the DOE performance targets for light-duty vehicles. Phase 1 tasks also included identification and technical justifications for candidate storage media and configurations that should be capable of reaching or exceeding the DOE targets. Phase 2 involved bench-level testing and

Solutions to commercializing metal hydride hydrogen storage products

International Nuclear Information System (INIS)

Tomlinson, J.J.; Belanger, R.

2004-01-01

'Full text:' Whilst the concept of a Hydrogen economy in the broad sense may for some analysts and Fuel Cell technology developers be an ever moving target the use of hydrogen exists and is growing in other markets today. The use of hydrogen is increasing. Who are the users? What are their unique needs? How can they better be served? As the use of hydrogen increases there are things we can do to improve the perception and handling of hydrogen as an industrial gas that will impact the future issues of hydrogen as a fuel thereby assisting the mainstream availability of hydrogen fuel a reality. Factors that will induce change in the way hydrogen is used, handled, transported and stored are the factors to concentrate development efforts on. Other factors include: cost; availability; safety; codes and standards; and regulatory authorities acceptance of new codes and standards. New methods of storage and new devices in which the hydrogen is stored will influence and bring about change and increased use. New innovative products based on Metal Hydride hydrogen storage will address some of the barriers to widely distributed hydrogen as a fuel or energy carrier to which successful fuel cell product commercialization is subject. Palcan has developed innovative products based on it's Rare Earth Metal Hydride alloy. Some of these innovations will aid the distribution of hydrogen as a fuel and offer alternatives to the existing hydrogen user and to the Fuel Cell product developer. An overview of the products and how these products will affect the distribution and use of hydrogen as an industrial gas and fuel is presented. (author)

Optimization and comprehensive characterization of metal hydride based hydrogen storage systems using in-situ Neutron Radiography

Science.gov (United States)

Börries, S.; Metz, O.; Pranzas, P. K.; Bellosta von Colbe, J. M.; Bücherl, T.; Dornheim, M.; Klassen, T.; Schreyer, A.

2016-10-01

For the storage of hydrogen, complex metal hydrides are considered as highly promising with respect to capacity, reversibility and safety. The optimization of corresponding storage tanks demands a precise and time-resolved investigation of the hydrogen distribution in scaled-up metal hydride beds. In this study it is shown that in situ fission Neutron Radiography provides unique insights into the spatial distribution of hydrogen even for scaled-up compacts and therewith enables a direct study of hydrogen storage tanks. A technique is introduced for the precise quantification of both time-resolved data and a priori material distribution, allowing inter alia for an optimization of compacts manufacturing process. For the first time, several macroscopic fields are combined which elucidates the great potential of Neutron Imaging for investigations of metal hydrides by going further than solely 'imaging' the system: A combination of in-situ Neutron Radiography, IR-Thermography and thermodynamic quantities can reveal the interdependency of different driving forces for a scaled-up sodium alanate pellet by means of a multi-correlation analysis. A decisive and time-resolved, complex influence of material packing density is derived. The results of this study enable a variety of new investigation possibilities that provide essential information on the optimization of future hydrogen storage tanks.

Ductile zirconium powder by hydride-dehydride process

Energy Technology Data Exchange (ETDEWEB)

Krishnan, T S [BHABHA ATOMIC RESEARCH CENTRE, BOMBAY (INDIA); CHAUDHARY, S [NUCLEAR FUEL COMPLEX, HYDERABAD (INDIA)

1976-09-01

The preparation of ductile zirconium powder by the hydride-dehydride process has been described. In this process massive zirconium obtained from Kroll reduction of ZrCl/sub 4/ is first rendered brittle by hydrogenation and the hydride crushed and ground in a ball mill to the required particle size. Hydrogen is then hot vacuum extracted to yield the metal powder. The process has been successfully employed for the production of zirconium powders with low oxygen content and having hardness values in the range of 115-130 BHN, starting from a zirconium sponge of 100-120 BHN hardness. Influence of surface characteristics of the starting metal on its hydriding behaviour has been studied and the optimum hydriding-dehydriding conditions established.

How to Analyse Metal Hydride Decomposition Temperatures Using a Sieverts’ Type Hydriding-Dehydriding Apparatus and Hydrogen-Storage Characteristics for an MgH2–Based Alloy

Directory of Open Access Journals (Sweden)

Young Jun KWAK

2018-02-01

Full Text Available In this work, a method to analyze metal hydride decomposition temperatures (the onset temperature of the metal hydride decomposition and the temperature for the maximum ratio of released gas quantity change with temperature change, of prepared samples were investigated using a Sieverts’ type hydriding-dehydriding apparatus, in which a back-pressure regulator was employed. The quantity of the gas released under 1.0 bar H2 was measured as the temperature was increased with a heating rate of 4 K/min. The variation in the ratio of released hydrogen quantity Hd change with temperature T change, dHd/dT, as a function of temperature was obtained and from the variation in dHd/dT with T, the metal hydride decomposition temperatures were analyzed. This analysis method can be used instead of thermal analysis methods such as thermogravimetric analysis (TGA, differential scanning calorimetry (DSC analysis, differential thermal analysis (DTA, and thermal desorption spectroscopy (TDS analysis. For this analysis, a sample with a composition of 89 wt.% MgH2 + 4.9 wt.% Ni + 1.7 wt.% Zn(BH42 + 1.0 wt% NaCl + 1.7 wt.% Ti + 1.7 wt % Fe (named MgH2-Ni-Zn(BH42-NaCl-Ti-Fe sample was prepared by planetary ball milling. In the prepared MgH2-Ni-Zn(BH42-NaCl-Ti-Fe sample, it is believed that MgH2 begins to decompose at about 575 K and dHd/dT reaches its peak at about 610 K.DOI: http://dx.doi.org/10.5755/j01.ms.24.1.17664

Low temperature hydrogenolysis of waxes to diesel range gasoline and light alkanes: Comparison of catalytic properties of group 4, 5 and 6 metal hydrides supported on silica-alumina

KAUST Repository

Norsic, Sébastien

2012-01-01

A series of metal hydrides (M = Zr, Hf, Ta, W) supported on silica-alumina were studied for the first time in hydrogenolysis of light alkanes in a continuous flow reactor. It was found that there is a difference in the reaction mechanism between d 0 metal hydrides of group 4 and d 0 ↔ d 2 metal hydrides of group 5 and group 6. Furthermore, the potential application of these catalysts has been demonstrated by the transformation of Fischer-Tropsch wax in a reactive distillation set-up into typical gasoline and diesel molecules in high selectivity (up to 86 wt%). Current results show that the group 4 metal hydrides have a promising yield toward liquid fuels.

Technique for production of calibrated metal hydride films

International Nuclear Information System (INIS)

Langley, R.A.; Browning, J.F.; Balsley, S.D.; Banks, J.C.; Doyle, B.L.; Wampler, W.R.; Beavis, L.C.

1999-01-01

A technique has been developed for producing calibrated metal hydride films for use in the measurement of high-energy (5--15 MeV) particle reaction cross sections for hydrogen and helium isotopes on hydrogen isotopes. Absolute concentrations of various hydrogen isotopes in the film is expected to be determined to better than ±2% leading to the capacity of accurately measuring various reaction cross sections. Hydrogen isotope concentrations from near 100% to 5% can be made accurately and reproducibly. This is accomplished with the use of high accuracy pressure measurements coupled with high accuracy mass spectrometric measurements of each constituent partial pressure of the gas mixture during loading of the metal occluder films. Various techniques are used to verify the amount of metal present as well as the amount of hydrogen isotopes; high energy ion scattering analysis, PV measurements before, during and after loading, and thermal desorption/mass spectrometry measurements. The most appropriate metal to use for the occluder film appears to be titanium but other occluder metals are also being considered. Calibrated gas ratio samples, previously prepared, are used for the loading gas. Deviations from this calibrated gas ratio are measured using mass spectrometry during and after the loading process thereby determining the loading of the various hydrogen isotopes. These techniques are discussed and pertinent issues presented

Metal hydride/chemical heat-pump development project. Phase I. Final report

Energy Technology Data Exchange (ETDEWEB)

Argabright, T.A.

1982-02-01

The metal hydride/chemical heat pump (MHHP) is a chemical heat pump containing two hydrides for the storage and/or recovery of thermal energy. It utilizes the heat of reaction of hydrogen with specific metal alloys. The MHHP design can be tailored to provide heating and/or cooling or temperature upgrading over a wide range of input and ambient temperatures. The system can thus be used with a variety of heat sources including waste heat, solar energy or a fossil fuel. The conceptual design of the MHHP was developed. A national market survey including a study of applications and market sectors was conducted. The technical tasks including conceptual development, thermal and mechanical design, laboratory verification of design and material performance, cost analysis and the detailed design of the Engineering Development Test Unit (EDTU) were performed. As a result of the market study, the temperature upgrade cycle of the MHHP was chosen for development. Operating temperature ranges for the upgrader were selected to be from 70 to 110/sup 0/C (160 to 230/sup 0/F) for the source heat and 140 to 190/sup 0/C (280 to 375/sup 0/F) for the product heat. These ranges are applicable to many processes in industries such as food, textile, paper and pulp, and chemical. The hydride pair well suited for these temperatures is LaNi/sub 5//LaNi/sub 4/ /sub 5/Al/sub 0/ /sub 5/. The EDTU was designed for the upgrade cycle. It is a compact finned tube arrangement enclosed in a pressure vessel. This design incorporates high heat transfer and low thermal mass in a system which maximizes the coefficient of performance (COP). It will be constructed in Phase II. Continuation of this effort is recommended.

Electron and nuclear magnetic resonances in compounds and metallic hydrides

International Nuclear Information System (INIS)

Brasil Filho, N.

1985-11-01

Proton pulsed Nuclear Magnetic Resonance measurements were performed on the metallic hydrides ZrCr 2 H x (x = 2, 3, 4) and ZrV 2 H y (y = 2, 3, 4, 5) as a function of temperature between 180 and 400K. The ultimate aim was the investigation of the relaxation mechanisms in these systems by means of the measurement of both the proton ( 1 H) spin-lattice (T 1 ) and spin-spin (T 2 ) relaxation times and to use these data to obtain information about the diffusive motion of the hydrogen atoms. The diffusional activation energies, the jump frequencies and the Korringa constant, C k , related with the conduction electron contribution to the 1 H relaxation were determined for the above hydrides as a function of hydrogen concentration. Our results were analysed in terms of the relaxation models described by Bloembergen, Purcell and Pound (BPP model) and by Torrey. The Korringa type relaxation due to the conduction electrons in metallic systems was also used to interpret the experimental results. We also present the Electron Paramagnetic Ressonance (EPR) study of Gd 3+ , Nd 3+ and Er 3+ ions as impurities in several AB 3 intermetallic compounds where A = LA, Ce, Y, Sc, Th, Zr and B = Rh, Ir, Pt. The results were analysed in terms of the multiband model previously suggested to explain the behaviour of the resonance parameter in AB 2 Laves Phase compounds. (author) [pt

Metal hydride store for hydrogen supply and cooling of fuel cell vehicles; Metallhydridspeicher zur Wasserstoffversorgung und Kuehlung von Brennstoffzellenfahrzeugen

Energy Technology Data Exchange (ETDEWEB)

Wenger, David

2009-07-01

In the context of the author's work, a compact, dynamic metal hydride store was developed which in addition to storing hydrogen can also support the thermomanagement of fuel cell vehicles in extreme situations. The requirements were identified using a semiphysical model of a fuel cell vehicle, and a store was dimensioned accordingly. Additionally, a metal hydride store model was developed on the basis of the balance equations. The model was validated by experiments on a specially designed and constructed store. The simulations enable the optimisation of the store geometry and the prediction of its efficiency in a given operating cycle. (orig.)

High Density Hydrogen Storage in Metal Hydride Composites with Air Cooling

OpenAIRE

Dieterich, Mila; Bürger, Inga; Linder, Marc

2015-01-01

INTRODUCTION In order to combine fluctuating renewable energy sources with the actual demand of electrical energy, storages are essential. The surplus energy can be stored as hydrogen to be used either for mobile use, chemical synthesis or reconversion when needed. One possibility to store the hydrogen gas at high volumetric densities, moderate temperatures and low pressures is based on a chemical reaction with metal hydrides. Such storages must be able to absorb and desorb the hydrogen qu...

High capacity V-based metal hydride electrodes for rechargeable batteries

OpenAIRE

Yang, Heng; Weadock, Nicholas J.; Tan, Hongjin; Fultz, Brent

2017-01-01

We report the successful development of Ti_(29)V_(62−x)Ni_9Cr_x (x = 0, 6, 12) body centered cubic metal hydride (MH) electrodes by addressing vanadium corrosion and dissolution in KOH solutions. By identifying oxygen as the primary source of corrosion and eliminating oxygen with an Ar-purged cell, the Cr-free Ti_(29)V_(62)Ni_9 alloy electrode achieved a maximum capacity of 594 mAh g^(-1), double the capacity of commercial AB_5 MH electrodes. With coin cells designed to minimize oxygen evolut...

On the thermodynamics of phase transitions in metal hydrides

Science.gov (United States)

di Vita, Andrea

2012-02-01

Metal hydrides are solutions of hydrogen in a metal, where phase transitions may occur depending on temperature, pressure etc. We apply Le Chatelier's principle of thermodynamics to a particular phase transition in TiH x , which can approximately be described as a second-order phase transition. We show that the fluctuations of the order parameter correspond to fluctuations both of the density of H+ ions and of the distance between adjacent H+ ions. Moreover, as the system approaches the transition and the correlation radius increases, we show -with the help of statistical mechanics-that the statistical weight of modes involving a large number of H+ ions (`collective modes') increases sharply, in spite of the fact that the Boltzmann factor of each collective mode is exponentially small. As a result, the interaction of the H+ ions with collective modes makes a tiny suprathermal fraction of the H+ population appear. Our results hold for similar transitions in metal deuterides, too. A violation of an -insofar undisputed-upper bound on hydrogen loading follows.

The impact of carbon materials on the hydrogen storage properties of light metal hydrides

NARCIS (Netherlands)

Adelhelm, P.A.; de Jongh, P.E.

2011-01-01

The safe and efficient storage of hydrogen is still one of the remaining challenges towards fuel cell powered cars. Metal hydrides are a promising class of materials as they allow the storage of large amounts of hydrogen in a small volume at room temperature and low pressures. However, usually the

Hydrogen storage in the form of metal hydrides

Science.gov (United States)

Zwanziger, M. G.; Santana, C. C.; Santos, S. C.

1984-01-01

Reversible reactions between hydrogen and such materials as iron/titanium and magnesium/ nickel alloy may provide a means for storing hydrogen fuel. A demonstration model of an iron/titanium hydride storage bed is described. Hydrogen from the hydride storage bed powers a converted gasoline electric generator.

Generalized computational model for high-pressure metal hydrides with variable thermal properties

DEFF Research Database (Denmark)

Mazzucco, Andrea; Rokni, Masoud

2015-01-01

This study considers a detailed 1D fueling model applied to a metal hydride system, with Ti1.1CrMn as the absorbing alloy, to predict the weight fraction of the absorbed hydrogen and the solid bed temperature. Dependencies of thermal conductivity and specific heat capacity upon pressure...... is estimated to be approximately 10%. Copyright (C) 2015, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved....

The growth of crystals of erbium hydride

International Nuclear Information System (INIS)

Grimshaw, J.A.; Spooner, F.J.; Wilson, C.G.; McQuillan, A.D.

1981-01-01

Crystals of the rare-earth hydride ErH 2 have been produced with face areas greater than a square millimetre and corresponding volumes exceeding those of earlier crystals by orders of magnitude. The hydride, which was produced in bulk polycrystalline form by hydriding erbium metal at 950 0 C, has been examined by optical and X-ray techniques. For material of composition ErH 2 and ErHsub(1.8) the size of the grains and their degree of strain appears to depend more on oxygen contamination during formation and on the subsequent cooling procedure, than on the size of erbium metal crystals in the starting material. (author)

Electrocatalytic hydride-forming compounds for rechageable batteries

NARCIS (Netherlands)

Notten, P.H.L.; Einerhand, R.E.F.

1991-01-01

Non-toxic intermetallic hydride-forming compounds are attractive alternatives to cadmium as the negative electrode materials in the new generation of Ni/metal hydride rechargeable batteries. High exchange currents and discharge efficiencies even at low temperatures can be achieved using highly

Blistering and hydride embrittlement

International Nuclear Information System (INIS)

Louthan, M.R. Jr.

1975-01-01

The effects of hydrogen on the mechanical properties of metals have been categorized into several groups. Two of the groups, hydrogen blistering and hydride embrittlement, are reasonably well understood, and problems relating to their occurrence may be avoided if that understanding is used as a basis for selecting alloys for hydrogen service. Blistering and hydride embrittlement are described along with several techniques of materials selection and used to minimize their adverse effects. (U.S.)

Preferred hydride growth orientations on oxide-coated gadolinium surfaces

International Nuclear Information System (INIS)

Benamar, G.M.; Schweke, D.; Kimmel, G.; Mintz, M.H.

2012-01-01

Highlights: ► The preferred hydride growth orientations on gadolinium metal coated by a thin oxide layer are presented. ► A preferred growth of the (1 0 0) h plane of the face centered cubic (FCC) GdH 2 is observed for the hydride spots forming below the oxidation layer. ► A change to the (1 1 1) h plane of the cubic hydride dominates for the hydride's Growth Centers. ► The texture change is attributed to the surface normal compressive stress component exerted by the oxidation layer on the developing hydride. - Abstract: The initial development of hydrides on polycrystalline gadolinium (Gd), as on some other hydride forming metals, is characterized by two sequential steps. The first step involves the rapid formation of a dense pattern of small hydride spots (referred to as the “small family” of hydrides) below the native oxidation layer. The second stage takes place when some of the “small family” nucleants (referred to as “growth centers”, GCs) break the oxide layer, leading to their rapid growth and finally to the massive hydriding of the sample. In the present study, the texture of the two hydride families was studied, by combining X-ray diffraction (XRD) analysis with a microscopic analysis of the hydride, using scanning electron microscopy (SEM) and atomic force microscopy (AFM). It has been observed that for the “small family”, a preferred growth of the (1 0 0) h plane of the cubic GdH 2 takes place, whereas for the GCs, a change to the (1 1 1) h plane of the cubic hydride dominates. These preferred growth orientations were analyzed by their structure relation with the (0 0 .1) m basal plane of the Gd metal. It has been concluded that the above texture change is due to the surface normal compressive stress component exerted by the oxidation overlayer on the developing hydride, preventing the (0 0 .1) m ||(1 1 1) h growth orientation. This stress is relieved upon the rupture of that overlayer and the development of the GCs, leading to

Getting metal-hydrides to do what you want them to

International Nuclear Information System (INIS)

Gruen, D.M.

1981-01-01

With the discovery of AB 5 compounds, intermetallic hydrides with unusual properties began to be developed (H dissociation pressures of one to several atmospheres, extremely rapid and reversible adsorption/desorption very large amounts of H adsorbed). This paper reviews the factors that must be controlled in order to modify these hydrides to make them useful. The system LaNi 5 + H 2 is used as example. Use of AB 5 hydrides to construct a chemical heat pumps is discussed. Results of a systematic study substituting Al for Ni are reported; the HYCSOS pump is described briefly. Use of hydrides as hydrogen getters (substituted ZrV 2 ) is also discussed. Finally, possible developments in intermetallic hydride research in the 1980's and the hydrogen economy are discussed. 10 figures

Recyclable hydrogen storage system composed of ammonia and alkali metal hydride

Energy Technology Data Exchange (ETDEWEB)

Yamamoto, Hikaru [Department of Quantum Matter, AdSM, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8530 (Japan); Miyaoka, Hiroki; Hino, Satoshi [Institute for Advanced Materials Research, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8530 (Japan); Nakanishi, Haruyuki [Higashi-Fuji Technical Center, Toyota Motor Corporation, 1200 Misyuku, Susono, Shizuoka 410-1193 (Japan); Ichikawa, Takayuki; Kojima, Yoshitsugu [Department of Quantum Matter, AdSM, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8530 (Japan); Institute for Advanced Materials Research, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8530 (Japan)

2009-12-15

Ammonia (NH{sub 3}) reacts with alkali metal hydrides MH (M = Li, Na, and K) in an exothermic reaction to release hydrogen (H{sub 2}) at room temperature, resulting that alkali metal amides (MNH{sub 2}) which are formed as by-products. In this work, hydrogen desorption properties of these systems and the condition for the recycle from MNH{sub 2} back to MH were investigated systematically. For the hydrogen desorption reaction, the reactivities of MH with NH{sub 3} were better following the atomic number of M on the periodic table, Li < Na < K. It was confirmed that the hydrogen absorption reaction of all the systems proceeded under 0.5 MPa of H{sub 2} flow condition below 300 C. (author)

Use of reversible hydrides for hydrogen storage

Science.gov (United States)

Darriet, B.; Pezat, M.; Hagenmuller, P.

1980-01-01

The addition of metals or alloys whose hydrides have a high dissociation pressure allows a considerable increase in the hydrogenation rate of magnesium. The influence of temperature and hydrogen pressure on the reaction rate were studied. Results concerning the hydriding of magnesium rich alloys such as Mg2Ca, La2Mg17 and CeMg12 are presented. The hydriding mechanism of La2Mg17 and CeMg12 alloys is given.

Mechanistic aspects of dinitrogen cleavage and hydrogenation to produce ammonia in catalysis and organometallic chemistry: relevance of metal hydride bonds and dihydrogen.

Science.gov (United States)

Jia, Hong-Peng; Quadrelli, Elsje Alessandra

2014-01-21

Dinitrogen cleavage and hydrogenation by transition-metal centers to produce ammonia is central in industry and in Nature. After an introductory section on the thermodynamic and kinetic challenges linked to N2 splitting, this tutorial review discusses three major classes of transition-metal systems (homogeneous, heterogeneous and biological) capable of achieving dissociation and hydrogenation of dinitrogen. Molecular complexes, solid-state Haber-Bosch catalytic systems, silica-supported tantalum hydrides and nitrogenase will be discussed. Emphasis is focused on the reaction mechanisms operating in the process of dissociation and hydrogenation of dinitrogen, and in particular on the key role played by metal hydride bonds and by dihydrogen in such reactions.

Hydride formation on deformation twin in zirconium alloy

Energy Technology Data Exchange (ETDEWEB)

Kim, Ju-Seong [Korea Atomic Energy Research Institute, 989-111 Daedeokdaero, Yuseong-gu, Daejeon, 305-353 (Korea, Republic of); Kim, Sung-Dae [Korea Institute of Material Science (KIMS), 797 Changwondaero, Changwon, Gyeongnam, 642-831 (Korea, Republic of); Yoon, Jonghun, E-mail: yooncsmd@gmail.com [Department of Mechanical Engineering, Hanyang University, 1271 Sa3-dong, Sangrok-gu, Ansan-si, Gyeonggi-do, 426-791 (Korea, Republic of)

2016-12-15

Hydrides deteriorate the mechanical properties of zirconium (Zr) alloys used in nuclear reactors. Intergranular hydrides that form along grain boundaries have been extensively studied due to their detrimental effects on cracking. However, it has been little concerns on formation of Zr hydrides correlated with deformation twins which is distinctive heterogeneous nucleation site in hexagonal close-packed metals. In this paper, the heterogeneous precipitation of Zr hydrides at the twin boundaries was visualized using transmission electron microscopy. It demonstrates that intragranular hydrides in the twinned region precipitates on the rotated habit plane by the twinning and intergranular hydrides precipitate along the coherent low energy twin boundaries independent of the conventional habit planes. Interestingly, dislocations around the twin boundaries play a substantial role in the nucleation of Zr hydrides by reducing the misfit strain energy.

Hydrogen Outgassing from Lithium Hydride

Energy Technology Data Exchange (ETDEWEB)

Dinh, L N; Schildbach, M A; Smith, R A; Balazs1, B; McLean II, W

2006-04-20

Lithium hydride is a nuclear material with a great affinity for moisture. As a result of exposure to water vapor during machining, transportation, storage and assembly, a corrosion layer (oxide and/or hydroxide) always forms on the surface of lithium hydride resulting in the release of hydrogen gas. Thermodynamically, lithium hydride, lithium oxide and lithium hydroxide are all stable. However, lithium hydroxides formed near the lithium hydride substrate (interface hydroxide) and near the sample/vacuum interface (surface hydroxide) are much less thermally stable than their bulk counterpart. In a dry environment, the interface/surface hydroxides slowly degenerate over many years/decades at room temperature into lithium oxide, releasing water vapor and ultimately hydrogen gas through reaction of the water vapor with the lithium hydride substrate. This outgassing can potentially cause metal hydriding and/or compatibility issues elsewhere in the device. In this chapter, the morphology and the chemistry of the corrosion layer grown on lithium hydride (and in some cases, its isotopic cousin, lithium deuteride) as a result of exposure to moisture are investigated. The hydrogen outgassing processes associated with the formation and subsequent degeneration of this corrosion layer are described. Experimental techniques to measure the hydrogen outgassing kinetics from lithium hydride and methods employing the measured kinetics to predict hydrogen outgassing as a function of time and temperature are presented. Finally, practical procedures to mitigate the problem of hydrogen outgassing from lithium hydride are discussed.

Performance of a full-scale ITER metal hydride storage bed in comparison with requirements

International Nuclear Information System (INIS)

Beloglazov, S.; Glugla, M.; Fanghaenel, E.; Perevezentsev, A.; Wagner, R.

2008-01-01

The storage of hydrogen isotopes as metal hydride is the technique chosen for the ITER Tritium Plant Storage and Delivery System (SDS). A prototype storage bed of a full-scale has been designed, manufactured and intensively tested at the Tritium Laboratory, addressing main performance parameters specified for the ITER application. The main requirements for the hydrogen storage bed are a strict physical limitation of the tritium storage capacity (currently 70 g T 2 ), a high supply flow rate of hydrogen isotopes, in-situ calorimetry capabilities with an accuracy of 1 g and a fully tritium compatible design. The pressure composition isotherm of the ZrCo hydrogen system, as a reference material for ITER, is characterised by significant slope. As a result technical implementation of the ZrCo hydride bed in the SDS system requires further considerations. The paper presents the experience from the operation of ZrCo getter bed including loading/de-loading operation, calorimetric loop performance, and active gas cooling of the bed for fast absorption operation. The implications of hydride material characteristics on the SDS system configuration and design are discussed. (authors)

Metal hydride hydrogen and heat storage systems as enabling technology for spacecraft applications

Energy Technology Data Exchange (ETDEWEB)

Reissner, Alexander, E-mail: reissner@fotec.at [FOTEC Forschungs- und Technologietransfer GmbH, Viktor Kaplan Straße 2, 2700 Wiener Neustadt (Austria); University of Applied Sciences Wiener Neustadt, Johannes Gutenberg-Straße 3, 2700 Wiener Neustadt (Austria); Pawelke, Roland H.; Hummel, Stefan; Cabelka, Dusan [FOTEC Forschungs- und Technologietransfer GmbH, Viktor Kaplan Straße 2, 2700 Wiener Neustadt (Austria); Gerger, Joachim [University of Applied Sciences Wiener Neustadt, Johannes Gutenberg-Straße 3, 2700 Wiener Neustadt (Austria); Farnes, Jarle, E-mail: Jarle.farnes@prototech.no [CMR Prototech AS, Fantoftvegen 38, PO Box 6034, 5892 Bergen (Norway); Vik, Arild; Wernhus, Ivar; Svendsen, Tjalve [CMR Prototech AS, Fantoftvegen 38, PO Box 6034, 5892 Bergen (Norway); Schautz, Max, E-mail: max.schautz@esa.int [European Space Agency, ESTEC – Keplerlaan 1, 2201 AZ Noordwijk Zh (Netherlands); Geneste, Xavier, E-mail: xavier.geneste@esa.int [European Space Agency, ESTEC – Keplerlaan 1, 2201 AZ Noordwijk Zh (Netherlands)

2015-10-05

Highlights: • A metal hydride tank concept for heat and hydrogen storage is presented. • The tank is part of a closed-loop reversible fuel cell system for space application. • For several engineering issues specific to the spacecraft application, solutions have been developed. • The effect of water contamination has been approximated for Ti-doped NaAlH{sub 4}. • A novel heat exchanger design has been realized by Selective Laser Melting. - Abstract: The next generation of telecommunication satellites will demand a platform payload performance in the range of 30+ kW within the next 10 years. At this high power output, a Regenerative Fuel Cell Systems (RFCS) offers an efficiency advantage in specific energy density over lithium ion batteries. However, a RFCS creates a substantial amount of heat (60–70 kJ per mol H{sub 2}) during fuel cell operation. This requires a thermal hardware that accounts for up to 50% of RFCS mass budget. Thus the initial advantage in specific energy density is reduced. A metal hydride tank for combined storage of heat and hydrogen in a RFCS may overcome this constraint. Being part of a consortium in an ongoing European Space Agency project, FOTEC is building a technology demonstrator for such a combined hydrogen and heat storage system.

Hydrogen desorption kinetics from zirconium hydride and zirconium metal in vacuum

International Nuclear Information System (INIS)

Hu, Xunxiang; Terrani, Kurt A.; Wirth, Brian D.

2014-01-01

The kinetics of hydrogen desorption from zirconium hydride is important in many nuclear design and safety applications. In this paper, a coordinated experimental and modeling study has been used to explicitly demonstrate the applicability of existing kinetic theories for hydrogen desorption from zirconium hydride and α-zirconium. A static synthesis method was used to produce δ-zirconium hydride, and the crystallographic phases of the zirconium hydride were confirmed by X-ray diffraction (XRD). Three obvious stages, involving δ-zirconium hydride, a two-phase region, and α-zirconium, were observed in the hydrogen desorption spectra of two zirconium hydride specimens with H/Zr ratios of 1.62 and 1.64, respectively, which were obtained using thermal desorption spectroscopy (TDS). A continuous, one-dimensional, two-phase moving boundary model, coupled with the zero- and second-order kinetics of hydrogen desorption from δ-zirconium hydride and α-zirconium, respectively, has been developed to reproduce the TDS experimental results. A comparison of the modeling predictions with the experimental results indicates that a zero-order kinetic model is valid for description of hydrogen flux away from the δ-hydride phase, and that a second-order kinetic model works well for hydrogen desorption from α-Zr if the activation energy of desorption is optimized to be 70% of the value reported in the literature

Hydrogen transmission/storage with a metal hydride/organic slurry

Energy Technology Data Exchange (ETDEWEB)

Breault, R.W.; Rolfe, J.; McClaine, A. [Thermo Power Corp., Waltham, MA (United States)

1998-08-01

Thermo Power Corporation has developed a new approach for the production, transmission, and storage of hydrogen. In this approach, a chemical hydride slurry is used as the hydrogen carrier and storage media. The slurry protects the hydride from unanticipated contact with moisture in the air and makes the hydride pumpable. At the point of storage and use, a chemical hydride/water reaction is used to produce high-purity hydrogen. An essential feature of this approach is the recovery and recycle of the spent hydride at centralized processing plants, resulting in an overall low cost for hydrogen. This approach has two clear benefits: it greatly improves energy transmission and storage characteristics of hydrogen as a fuel, and it produces the hydrogen carrier efficiently and economically from a low cost carbon source. The preliminary economic analysis of the process indicates that hydrogen can be produced for $3.85 per million Btu based on a carbon cost of $1.42 per million Btu and a plant sized to serve a million cars per day. This compares to current costs of approximately $9.00 per million Btu to produce hydrogen from $3.00 per million Btu natural gas, and $25 per million Btu to produce hydrogen by electrolysis from $0.05 per Kwh electricity. The present standard for production of hydrogen from renewable energy is photovoltaic-electrolysis at $100 to $150 per million Btu.

Analytical and numerical models of uranium ignition assisted by hydride formation

International Nuclear Information System (INIS)

Totemeier, T.C.; Hayes, S.L.

1996-01-01

Analytical and numerical models of uranium ignition assisted by the oxidation of uranium hydride are described. The models were developed to demonstrate that ignition of large uranium ingots could not occur as a result of possible hydride formation during storage. The thermodynamics-based analytical model predicted an overall 17 C temperature rise of the ingot due to hydride oxidation upon opening of the storage can in air. The numerical model predicted locally higher temperature increases at the surface; the transient temperature increase quickly dissipated. The numerical model was further used to determine conditions for which hydride oxidation does lead to ignition of uranium metal. Room temperature ignition only occurs for high hydride fractions in the nominally oxide reaction product and high specific surface areas of the uranium metal

Bond Formation in Diatomic Transition Metal Hydrides: Insights from the Analysis of Domain-Averaged Fermi Holes

Czech Academy of Sciences Publication Activity Database

Cooper, D.L.; Ponec, Robert

2013-01-01

Roč. 113, č. 2 (2013), s. 102-111 ISSN 0020-7608 R&D Projects: GA ČR GA203/09/0118 Institutional support: RVO:67985858 Keywords : transition metal hydrides * bond formation * analysis of domain averaged Fermi holes Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 1.166, year: 2013

Reviews on the Japanese Patent Applications Regarding Nickel/Metal Hydride Batteries

Directory of Open Access Journals (Sweden)

Taihei Ouchi

2016-06-01

Full Text Available The Japanese Patent Applications filed on the topic of nickel/metal hydride (Ni/MH batteries have been reviewed. Patent applications filed by the top nine battery manufacturers (Matsushita, Sanyo, Hitachi Maxell, Yuasa, Toshiba, FDK, Furukawa, Japan Storage, and Shin-kobe, five component suppliers (Tanaka, Mitsui, Santoku, Japan Metals & Chemicals Co. (JMC, and Shin-Etsu, and three research institutes (Industrial Research Institute (ISI, Agency of Industrial Science and Technology (AIST, and Toyota R & D were chosen as the main subjects for this review, based on their production volume and contribution to the field. By reviewing these patent applications, we can have a clear picture of the technology development in the Japanese battery industry. These patent applications also provide insights, know-how, and future directions for engineers and scientists working in the rechargeable battery field.

Pyrophoric behaviour of uranium hydride and uranium powders

Science.gov (United States)

Le Guyadec, F.; Génin, X.; Bayle, J. P.; Dugne, O.; Duhart-Barone, A.; Ablitzer, C.

2010-01-01

Thermal stability and spontaneous ignition conditions of uranium hydride and uranium metal fine powders have been studied and observed in an original and dedicated experimental device placed inside a glove box under flowing pure argon. Pure uranium hydride powder with low amount of oxide (Oxidation mechanisms are proposed.

Permeation rates for RTF metal hydride vessels

International Nuclear Information System (INIS)

Klein, J.E.

1992-01-01

Contamination rates have been estimated for the RTF nitrogen heating and cooling system (NH and CS) due to tritium permeation through the walls of metal hydride vessels. Tritium contamination of the NH and CS will be seen shortly after start-up of the RTF with the majority of it coming from the TCAP units. Contamination rates of the NH and CS are estimated to exceed 400 Ci/year after three years of operation and will elevate tritium concentrations in the NH and CS above 6 x 10 -3 μCi/cc. To reduce tritium activity in the NH and CS, a stripper or ''getter'' bed may need to be installed in the NH and CS. Increasing the purge rate of nitrogen from the NH and CS is shown to be an impractical method for reducing tritium activity due to the high purge rates required. Stripping of the NH and CS nitrogen in the glove box stripper system will give a temporary lowering of tritium activity in the NH and CS, but tritium activity will return to its previous level in approximately two weeks

Determination of phosphorus in metals by neutron activation and chemical separation as hydride

International Nuclear Information System (INIS)

Rouchaud, J.C.; Fedoroff, M.

1993-01-01

Phosphorous at trace levels alters the properties of metals and alloys. Its determination was investigated by radiochemical neutron activation analysis. Separation by solvent extraction or by evolution as P 0 showed to be neither selective nor quantitative in presence of a metallic matrix. Therefore, a new method of separation by reduction to phosphorous hydride followed by liquid scintillation counting was investigated. This method is quantitative in the case of non-radioactive iron doped with radioactive phosphorus. At present, the separation is not quantitative for irradiation iron samples, owing probably to hot atom or radiation effects. A detection limit of 0.002 μg is expected. (author) 10 refs.; 1 fig.; 3 tabs

Scattering influences in quantitative fission neutron radiography for the in situ analysis of hydrogen distribution in metal hydrides

Energy Technology Data Exchange (ETDEWEB)

Börries, S., E-mail: stefan.boerries@hzg.de [Helmholtz-Zentrum Geesthacht, Centre for Materials and Coastal Research, Max-Planck-Strasse 1, D-21502 Geesthacht (Germany); Metz, O.; Pranzas, P.K. [Helmholtz-Zentrum Geesthacht, Centre for Materials and Coastal Research, Max-Planck-Strasse 1, D-21502 Geesthacht (Germany); Bücherl, T. [ZTWB Radiochemie München (RCM), Technische Universität München (TUM), Walther-Meissner-Str. 3, D-85748 Garching (Germany); Söllradl, S. [Forschungs-Neutronenquelle Heinz Maier-Leibnitz (FRMII), Technische Universität München (TUM), Lichtenbergstr. 1, D-85748 Garching (Germany); Dornheim, M.; Klassen, T.; Schreyer, A. [Helmholtz-Zentrum Geesthacht, Centre for Materials and Coastal Research, Max-Planck-Strasse 1, D-21502 Geesthacht (Germany)

2015-10-11

In situ neutron radiography allows for the time-resolved study of hydrogen distribution in metal hydrides. However, for a precise quantitative investigation of a time-dependent hydrogen content within a host material, an exact knowledge of the corresponding attenuation coefficient is necessary. Additionally, the effect of scattering has to be considered as it is known to violate Beer's law, which is used to determine the amount of hydrogen from a measured intensity distribution. Within this study, we used a metal hydride inside two different hydrogen storage tanks as host systems, consisting of steel and aluminum. The neutron beam attenuation by hydrogen was investigated in these two different setups during the hydrogen absorption process. A linear correlation to the amount of absorbed hydrogen was found, allowing for a readily quantitative investigation. Further, an analysis of scattering contributions on the measured intensity distributions was performed and is described in detail.

Achievement report for 1st phase (fiscal 1974-80) Sunshine Program research and development - Hydrogen energy. Research on transportation of hydrogen in the form of metallic hydride; 1974-1980 nendo kinzoku suisokabutsu ni yoru suiso no yuso gijutsu no kenkyu seika hokokusho

Energy Technology Data Exchange (ETDEWEB)

NONE

1981-03-01

This report concerns the transportation and storage of hydrogen using metallic hydrides that perform absorption and desorption of hydrogen. Alloys useable for this purpose have to be capable of reversibly absorbing and desorbing hydrogen within a certain temperature range. In the absence of guidelines to follow in the quest for such alloys, the efforts at discovering them turned out to be a continual series of trials and errors. Researches were conducted into the hydrogenation reaction of Mg and Mg-based alloys and into hydrides of V-based alloys, and into Zr-based alloy hydrides such as the ZrMn{sub 2} hydride, ZrNiMn hydride, Zr(Fe{sub x}Mn{sub 1-x}){sub 2} hydrides, TiZrFe{sub 2} hydride, Zr{sub x}Ti{sub 1-x}(Fe{sub y}Mn{sub 1-y}) hydrides, etc. Also studied were the electronics of hydrogen in metallic hydrides, rates of reaction between Mg-Ni-based alloys and hydrogen systems, endurance tests for hydrides of Mg-Ni-based alloys, effects exerted by absorbed gas molecules during the storage of hydrogen in Mg-Ni-based alloys, effective thermal conductivity in a layer filled with a metallic hydride, metallic hydride-aided hydrogen transportation systems, chemical boosters, etc. (NEDO)

Design of Hydrogen Storage Alloys/Nanoporous Metals Hybrid Electrodes for Nickel-Metal Hydride Batteries

Science.gov (United States)

Li, M. M.; Yang, C. C.; Wang, C. C.; Wen, Z.; Zhu, Y. F.; Zhao, M.; Li, J. C.; Zheng, W. T.; Lian, J. S.; Jiang, Q.

2016-06-01

Nickel metal hydride (Ni-MH) batteries have demonstrated key technology advantages for applications in new-energy vehicles, which play an important role in reducing greenhouse gas emissions and the world’s dependence on fossil fuels. However, the poor high-rate dischargeability of the negative electrode materials—hydrogen storage alloys (HSAs) limits applications of Ni-MH batteries in high-power fields due to large polarization. Here we design a hybrid electrode by integrating HSAs with a current collector of three-dimensional bicontinuous nanoporous Ni. The electrode shows enhanced high-rate dischargeability with the capacity retention rate reaching 44.6% at a discharge current density of 3000 mA g-1, which is 2.4 times that of bare HSAs (18.8%). Such a unique hybrid architecture not only enhances charge transfer between nanoporous Ni and HSAs, but also facilitates rapid diffusion of hydrogen atoms in HSAs. The developed HSAs/nanoporous metals hybrid structures exhibit great potential to be candidates as electrodes in high-performance Ni-MH batteries towards applications in new-energy vehicles.

Report on the basic design of a hydrogen transportation system utilizing metal hydrides and the evaluation thereon; Kinzoku suisokabutsu wo riyoshita suiso yuso system no kihon sekkei to sono hyoka ni kansuru hokokusho

Energy Technology Data Exchange (ETDEWEB)

NONE

1981-03-26

This paper describes a hydrogen transportation system utilizing metal hydrides. For a storage method for moving, metal hydrides having high hydrogen containing performance like Mg-based hydrides would have high portability, less weight disadvantage, and high economic performance. In the fixed location storage, metal hydrides are superior in safety and maintenance cost to the conventional high-pressure gas holder and liquefied hydrogen storage. Because of their high dependence on equilibrium pressure and temperature, the significance of development thereof is large as the source of high-pressure hydrogen generation and motive force. More effective utilization of low-level heat, and separation and refining of hydrogen may also be expected. With regard to fuel supply for hydrogen fueled automobiles, metal hydrides are better in safety and total energy cost than liquefied hydrogen, but have a number of disadvantageous points in weight demerit. Eliminating the weight demerit would be the central issue of the development. Accompanying the development of hydrogen fueled automobiles, there are a number of technological elements to be developed on fuel supply system, such as storage, moving and transportation in hydrogen manufacturing sites, and filling and storage at using sites. Arranging the related infrastructures would be the issue. (NEDO)

Thermodynamic and structural properties of ball-milled mixtures composed of nano-structural graphite and alkali(-earth) metal hydride

International Nuclear Information System (INIS)

Miyaoka, Hiroki; Ichikawa, Takayuki; Fujii, Hironobu

2007-01-01

Hydrogen desorption properties of mechanically milled materials composed of nano-structural hydrogenated-graphite (C nano H x ) and alkali(-earth) metal hydride (MH; M = Na, Mg and Ca) were investigated from the thermodynamic and structural points of view. The hydrogen desorption temperature for all the C nano H x and MH composites was obviously lower than that of the corresponding each hydride. In addition, the desorption of hydrocarbons from C nano H x was significantly suppressed by making composite of C nano H x with MH, even though C nano H x itself thermally desorbs a considerably large amount of hydrocarbons. These results indicate that an interaction exists between C nano H x and MH, and hydrogen in both the phases is destabilized by a close contact between polar C-H groups in C nano H x and the MH solid phase. Moreover, a new type of chemical bonding between the nano-structural carbon (C nano ) and the Li, Ca, or Mg metal atoms may be formed after hydrogen desorption. Thus, the above metal-C-H system would be recognized as a new family of H-storage materials

Study of hydrogenation for pulverization of rare earth alloys with Nb for metal hydride electrodes

International Nuclear Information System (INIS)

Ferreira, Eliner Affonso

2013-01-01

In this work were studied La ,7 Mg 0,3 Al 0,3 Mn 0,4 Co (0.5-x) NbxNi 3.8 (x= 0 - 0.5) and La 0,7 Mg 0,3 Al 0,3 Mn 0.4 Nb (05+x) Co 0,5 Ni (3.8-x) . (x=0.3; 0.5;1.3) alloys for negative electrodes of the Nickel-Metal Hydride batteries. The hydrogenation of the alloys was performed varying pressing of H 2 (2 and 9 bar). The discharge capacity of the nickel-metal hydride batteries were analyzed in the Arbin BT-4 electrical test equipment. The as-cast alloys were analyzed by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDX) and X-Ray diffraction. The increasing Niobium addition in the alloys decreased cycle life and the maximum discharge capacity of the batteries. The maximum discharge capacity was obtained with the La .7 Mg 0.3 Al 0.3 Mn 0,4 Co 0.5 Ni 3.8 (45.36 mAh) and the battery which presented the best performance was La .7 Mg 0.3 Al 0.3 Mn 0.4 Co 0.5 Nb 0.1 Ni 3.8 (44.94 mAh). (author)

Complex transition metal hydrides incorporating ionic hydrogen: Synthesis and characterization of Na{sub 2}Mg{sub 2}FeH{sub 8} and Na{sub 2}Mg{sub 2}RuH{sub 8}

Energy Technology Data Exchange (ETDEWEB)

Humphries, Terry D., E-mail: terry_humphries81@hotmail.com [WPI-Advanced Institute for Materials Research, Tohoku University, Sendai 980-8577 (Japan); Takagi, Shigeyuki; Li, Guanqiao; Matsuo, Motoaki; Sato, Toyoto [Institute for Materials Research, Tohoku University, Sendai 980-8577 (Japan); Sørby, Magnus H.; Deledda, Stefano; Hauback, Bjørn C. [Physics Department, Institute for Energy Technology, Kjeller NO-2027 (Norway); Orimo, Shin-ichi [WPI-Advanced Institute for Materials Research, Tohoku University, Sendai 980-8577 (Japan); Institute for Materials Research, Tohoku University, Sendai 980-8577 (Japan)

2015-10-05

Highlights: • Structures of Na{sub 2}Mg{sub 2}FeH{sub 8} and Na{sub 2}Mg{sub 2}RuH{sub 8} have been determined by XRD and PND. • Compounds incorporate independently coordinated ionic and covalent hydrogen. • [TH{sub 6}]{sup 4−} anion is surrounded by a cubic array of four Mg{sup 2+} and four Na{sup +} cations. • H{sup −} anions are octahedrally coordinated by four Na{sup +} and two Mg{sup 2+} cations. • Vibrational modes of the H{sup −} anions and complex hydride anion are observed. - Abstract: A new class of quaternary complex transition metal hydrides (Na{sub 2}Mg{sub 2}TH{sub 8} (T = Fe, Ru)) have been synthesized and their structures determined by combined synchrotron radiation X-ray and powder neutron diffraction. The compounds can be considered as a link between ionic and complex hydrides in terms of incorporating independently coordinated ionic and covalent hydrogen. These novel isostructural complex transition metal hydrides crystallize in the orthorhombic space group Pbam, where the octahedral complex hydride anion is surrounded by a cubic array of four Mg{sup 2+} and four Na{sup +} cations, forming distinct two-dimensional layers. An intriguing feature of these materials is the distorted octahedral coordination of the isolated H{sup −} anions by four Na{sup +} and two Mg{sup 2+} cations, which form layers between the transition metal containing layers. The vibrational modes of the H{sup −} anions and complex hydride anion are independently observed for the first time in a quaternary complex transition metal hydride system by Raman and IR spectroscopy.

Chemical Hydride Slurry for Hydrogen Production and Storage

Energy Technology Data Exchange (ETDEWEB)

McClaine, Andrew W

2008-09-30

The purpose of this project was to investigate and evaluate the attractiveness of using a magnesium chemical hydride slurry as a hydrogen storage, delivery, and production medium for automobiles. To fully evaluate the potential for magnesium hydride slurry to act as a carrier of hydrogen, potential slurry compositions, potential hydrogen release techniques, and the processes (and their costs) that will be used to recycle the byproducts back to a high hydrogen content slurry were evaluated. A 75% MgH₂ slurry was demonstrated, which was just short of the 76% goal. This slurry is pumpable and storable for months at a time at room temperature and pressure conditions and it has the consistency of paint. Two techniques were demonstrated for reacting the slurry with water to release hydrogen. The first technique was a continuous mixing process that was tested for several hours at a time and demonstrated operation without external heat addition. Further work will be required to reduce this design to a reliable, robust system. The second technique was a semi-continuous process. It was demonstrated on a 2 kWh scale. This system operated continuously and reliably for hours at a time, including starts and stops. This process could be readily reduced to practice for commercial applications. The processes and costs associated with recycling the byproducts of the water/slurry reaction were also evaluated. This included recovering and recycling the oils of the slurry, reforming the magnesium hydroxide and magnesium oxide byproduct to magnesium metal, hydriding the magnesium metal with hydrogen to form magnesium hydride, and preparing the slurry. We found that the SOM process, under development by Boston University, offers the lowest cost alternative for producing and recycling the slurry. Using the H2A framework, a total cost of production, delivery, and distribution of $4.50/kg of hydrogen delivered or $4.50/gge was determined. Experiments performed at Boston

Z-H Bond Activation in (Di)hydrogen Bonding as a Way to Proton/Hydride Transfer and H2 Evolution.

Science.gov (United States)

Belkova, Natalia V; Filippov, Oleg A; Shubina, Elena S

2018-02-01

The ability of neutral transition-metal hydrides to serve as a source of hydride ion H - or proton H + is well appreciated. The hydride ligands possessing a partly negative charge are proton accepting sites, forming a dihydrogen bond, M-H δ- ⋅⋅⋅ δ+ HX (M=transition metal or metalloid). On the other hand, some metal hydrides are able to serve as a proton source and give hydrogen bond of M-H δ+ ⋅⋅⋅X type (X=organic base). In this paper we analyse recent works on transition-metal and boron hydrides showing i) how formation of an intermolecular complex between the reactants changes the Z-H (M-H and X-H) bond polarity and ii) what is the implication of such activation in the mechanisms of hydrides reactions. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Atom Probe Analysis of Ex Situ Gas-Charged Stable Hydrides.

Science.gov (United States)

Haley, Daniel; Bagot, Paul A J; Moody, Michael P

2017-04-01

In this work, we report on the atom probe tomography analysis of two metallic hydrides formed by pressurized charging using an ex situ hydrogen charging cell, in the pressure range of 200-500 kPa (2-5 bar). Specifically we report on the deuterium charging of Pd/Rh and V systems. Using this ex situ system, we demonstrate the successful loading and subsequent atom probe analysis of deuterium within a Pd/Rh alloy, and demonstrate that deuterium is likely present within the oxide-metal interface of a native oxide formed on vanadium. Through these experiments, we demonstrate the feasibility of ex situ hydrogen analysis for hydrides via atom probe tomography, and thus a practical route to three-dimensional imaging of hydrogen in hydrides at the atomic scale.

Hydrogenation of cyclohexene with LaNi5−xAlxHn metal hydrides suspended in cyclohexane or ethanol

NARCIS (Netherlands)

Snijder, E.D.; Versteeg, G.F.; Swaaij, W.P.M. van

1993-01-01

The hydrogenation of cyclohexene on the metal hydride forming alloys LaNi4.8Al0.2, LaNi4.9Al0.1 and LaNi5, all suspended in cyclohexane and LaNi5 suspended in ethanol, has been investigated. Two sources for hydrogen are recognized: hydrogen supplied by the gas phase and hydrogen which is available

Hydrogenation of cyclohexene with LaNi@#5@#-@#x@#Al@#x@#Hn metal hydrides, suspended in cyclohexane or ethanol

NARCIS (Netherlands)

Snijder, E.D.; Snijder, E.D.; Versteeg, Geert; van Swaaij, Willibrordus Petrus Maria

1993-01-01

The hydrogenation of cyclohexene on the metal hydride forming alloys LaNi4.8Al0.2, LaNi4.9Al0.1 and LaNi5, all suspended in cyclohexane and LaNi5 suspended in ethanol, has been investigated. Two sources for hydrogen are recognized: hydrogen supplied by the gas phase and hydrogen which is available

Hydrogenation of the rare earth alloys for production negative electrodes of nickel-metal hydride batteries

International Nuclear Information System (INIS)

Casini, Julio Cesar Serafim

2011-01-01

In this work were studied of La 0.7-x Mg x Pr 0.3 Al 0.3 Mn 0.4 Co 0.5 Ni 3.8 (X = 0 and 0.7) alloys for negative electrodes of the nickel-metal hydride batteries. The hydrogenation of the alloys was performed varying pressing of H 2 (2 and 10 bar) and temperature (room and 500 ℃). The discharge capacity of the nic kel-metal hydride batteries were analyzed in ARBIN BT- 4 electrical test equipment. The as-cast alloys were analyzed by scanning electron microscopy (SEM), energy disperse spectroscopy (EDX) and X-Ray diffraction. The increasing Mg addition in the alloy increases maximum discharge capacity but decrease cycle life of the batteries. The maximum discharge capacity was obtained with the Mg 0.7 Pr 0.3 Al 0.3 Mn 0.4 Co 0.5 Ni 3.8 alloy (60 mAh) and the battery which presented the best performance was La 0.4 Mg 0.3 Pr 0.3 Al 0.3 Mn 0.4 Co 0.5 Ni 3.8 alloy (53 mAh and 150 cycles). The H 2 capability of absorption was diminished for increased Mg addition and no such effect occurs for Mg 0.7 Pr 0.3 Al 0.3 Mn 0.4 Co 0.5 Ni 3.8 alloy. (author)

Process optimization and kinetics for leaching of rare earth metals from the spent Ni-metal hydride batteries.

Science.gov (United States)

Meshram, Pratima; Pandey, B D; Mankhand, T R

2016-05-01

Nickel-metal hydride batteries (Ni-MH) contain not only the base metals, but valuable rare earth metals (REMs) viz. La, Sm, Nd, Pr and Ce as well. In view of the importance of resource recycling and assured supply of the contained metals in such wastes, the present study has focussed on the leaching of the rare earth metals from the spent Ni-MH batteries. The conditions for the leaching of REMs from the spent batteries were optimized as: 2M H2SO4, 348K temperature and 120min of time at a pulp density (PD) of 100g/L. Under this condition, the leaching of 98.1% Nd, 98.4% Sm, 95.5% Pr and 89.4% Ce was achieved. Besides the rare earth metals, more than 90% of base metals (Ni, Co, Mn and Zn) were also leached out in this condition. Kinetic data for the dissolution of all the rare earth metals showed the best fit to the chemical control shrinking core model. The leaching of metals followed the mechanism involving the chemical reaction proceeding on the surface of particles by the lixiviant, which was corroborated by the XRD phase analysis and SEM-EDS studies. The activation energy of 7.6, 6.3, 11.3 and 13.5kJ/mol was acquired for the leaching of neodymium, samarium, praseodymium and cerium, respectively in the temperature range 305-348K. From the leach liquor, the mixed rare earth metals were precipitated at pH∼1.8 and the precipitated REMs was analyzed by XRD and SEM studies to determine the phases and the morphological features. Copyright © 2015. Published by Elsevier Ltd.

Hydrogen energy technology development conference. From production of hydrogen to application of utilization technologies and metal hydrides, and examples; Suiso energy gijutsu kaihatsu kaigi. Suiso no seizo kara riyo gijutsu kinzoku suisokabutsu no oyo to jirei

Energy Technology Data Exchange (ETDEWEB)

NONE

1984-02-14

The hydrogen energy technology development conference was held on February 14 to 17, 1984 in Tokyo. For hydrogen energy systems and production of hydrogen from water, 6 papers were presented for, e.g., the future of hydrogen energy, current state and future of hydrogen production processes, and current state of thermochemical hydrogen technology development. For hydrogen production, 6 papers were presented for, e.g., production of hydrogen from steel mill gas, coal and methanol. For metal hydrides and their applications, 6 papers were presented for, e.g., current state of development of hydrogen-occluding alloy materials, analysis of heat transfer in metal hydride layers modified with an organic compound and its simulation, and development of a large-size hydrogen storage system for industrial purposes. For hydrogen utilization technologies, 8 papers were presented for, e.g., combustion technologies, engines incorporating metal hydrides, safety of metal hydrides, hydrogen embrittlement of system materials, development trends of phosphate type fuel cells, and alkali and other low-temperature type fuel cells. (NEDO)

Growth and decomposition of Lithium and Lithium hydride on Nickel

DEFF Research Database (Denmark)

Engbæk, Jakob; Nielsen, Gunver; Nielsen, Jane Hvolbæk

2006-01-01

In this paper we have investigated the deposition, structure and decomposition of lithium and lithium-hydride films on a nickel substrate. Using surface sensitive techniques it was possible to quantify the deposited Li amount, and to optimize the deposition procedure for synthesizing lithium......-hydride films. By only making thin films of LiH it is possible to study the stability of these hydride layers and compare it directly with the stability of pure Li without having any transport phenomena or adsorbed oxygen to obscure the results. The desorption of metallic lithium takes place at a lower...... temperature than the decomposition of the lithium-hydride, confirming the high stability and sintering problems of lithium-hydride making the storage potential a challenge. (c) 2006 Elsevier B.V. All rights reserved....

Cesium platinide hydride 4Cs{sub 2}Pt.CsH: an intermetallic double salt featuring metal anions

Energy Technology Data Exchange (ETDEWEB)

Smetana, Volodymyr [Ames Laboratory, US Department of Energy, and Critical Materials Institute, Ames, Iowa, 50011-3020 (United States); Mudring, Anja-Verena [Ames Laboratory, US Department of Energy, and Critical Materials Institute, Ames, Iowa, 50011-3020 (United States); Department of Materials Sciences and Engineering, Iowa State University, Ames, Iowa, 50011-3111 (United States)

2016-11-14

With Cs{sub 9}Pt{sub 4}H a new representative of ionic compounds featuring metal anions can be added to this rare-membered family. Cs{sub 9}Pt{sub 4}H exhibits a complex crystal structure containing Cs{sup +} cations, Pt{sup 2-} and H{sup -} anions. Being a red, transparent compound its band gap is in the visible range of the electromagnetic spectrum and the ionic type of bonding is confirmed by quantum chemical calculations. This cesium platinide hydride can formally be considered as a double salt of the ''alloy'' cesium-platinum, or better cesium platinide, Cs{sub 2}Pt, and the salt cesium hydride CsH according to Cs{sub 9}Pt{sub 4}H≡4 Cs{sub 2}Pt.CsH. (copyright 2016 Wiley-VCH Verlag GmbH and Co. KGaA, Weinheim)

Hydrogen storage properties of carbon nanomaterials and carbon containing metal hydrides

Energy Technology Data Exchange (ETDEWEB)

Maehlen, Jan Petter

2003-07-01

The topic of this thesis is structural investigations of carbon containing materials in respect to their hydrogen storage properties. This work was initially triggered by reports of extremely high hydrogen storage capacities of specific carbon nanostructures. It was decided to try to verify and understand the mechanisms in play in case of the existence of such high hydrogen densities in carbon. Two different routes towards the goal were employed; by studying selected hydrides with carbon as one of its constituents (mainly employing powder diffraction techniques in combination with hydrogen absorption and desorption measurements) and by carefully conducting hydrogen sorption experiments on what was believed to be the most ''promising'' carbon nanomaterial sample. In the latter case, a lot of effort was attributed to characterisations of different carbon nanomaterial containing samples with the aid of electron microscopy. Three different carbon-containing metal hydride systems, Y2C-H, YCoC-H and Y5SiC0.2-H, were examined. A relation between hydrogen occupation and the local arrangement of metal and carbon atoms surrounding the hydrogen sites was established. Several characteristic features of the compounds were noted in addition to solving the structure of the former unknown deuterideY5Si3C0.2D2.0 by the use of direct methods. Several carbon-nanomaterial containing samples were studied by means of transmission electron microscopy and powder diffraction, thus gaining knowledge concerning the structural aspects of nanomaterials. Based on these investigations, a specific sample containing a large amount of open-ended single-wall carbon nanotubes was chosen for subsequent hydrogen storage experiments. The latter experiments revealed moderate hydrogen storage capacities of the nanotubes not exceeding the values obtained for more conventional forms of carbon. These two different routes in investigating the hydrogen storage properties of carbon and carbon containing alloys

Hydrogen storage properties of carbon nanomaterials and carbon containing metal hydrides

Energy Technology Data Exchange (ETDEWEB)

Maehlen, Jan Petter

2003-07-01

The topic of this thesis is structural investigations of carbon containing materials in respect to their hydrogen storage properties. This work was initially triggered by reports of extremely high hydrogen storage capacities of specific carbon nanostructures. It was decided to try to verify and understand the mechanisms in play in case of the existence of such high hydrogen densities in carbon. Two different routes towards the goal were employed; by studying selected hydrides with carbon as one of its constituents (mainly employing powder diffraction techniques in combination with hydrogen absorption and desorption measurements) and by carefully conducting hydrogen sorption experiments on what was believed to be the most ''promising'' carbon nanomaterial sample. In the latter case, a lot of effort was attributed to characterisations of different carbon nanomaterial containing samples with the aid of electron microscopy. Three different carbon-containing metal hydride systems, Y2C-H, YCoC-H and Y5SiC0.2-H, were examined. A relation between hydrogen occupation and the local arrangement of metal and carbon atoms surrounding the hydrogen sites was established. Several characteristic features of the compounds were noted in addition to solving the structure of the former unknown deuterideY5Si3C0.2D2.0 by the use of direct methods. Several carbon-nanomaterial containing samples were studied by means of transmission electron microscopy and powder diffraction, thus gaining knowledge concerning the structural aspects of nanomaterials. Based on these investigations, a specific sample containing a large amount of open-ended single-wall carbon nanotubes was chosen for subsequent hydrogen storage experiments. The latter experiments revealed moderate hydrogen storage capacities of the nanotubes not exceeding the values obtained for more conventional forms of carbon. These two different routes in investigating the hydrogen storage properties of carbon and

Some new techniques in tritium gas handling as applied to metal hydride synthesis

International Nuclear Information System (INIS)

Nasise, J.E.

1988-01-01

A state-of-the-art tritium Hydriding Synthesis System (HSS) was designed and built to replace the existing system within the Tritium Salt Facility (TSF) at the Los Alamos National Laboratory. This new hydriding system utilizes unique fast-cycling 7.9 mole uranium beds (47.5g of T at 100% loading) and novel gas circulating hydriding furnaces. Tritium system components discussed include fast-cycling uranium beds, circulating gas hydriding furnaces, valves, storage volumes, manifolds, gas transfer pumps, and graphic display and control consoles. Many of the tritium handling and processing techniques incorporated into this system are directly applicable to today's fusion fuel loops. 12 refs., 7 figs

Screening of metal hydride pairs for closed thermal energy storage systems

International Nuclear Information System (INIS)

Aswin, N.; Dutta, Pradip; Murthy, S. Srinivasa

2016-01-01

Thermal energy storage systems based on metal/hydrides usually are closed systems composed of two beds of metal/alloy – one meant for energy storage and the other for hydrogen storage. It can be shown that a feasible operating cycle for such a system using a pair of metals/alloys operating between specified temperature values can be ensured if the equilibrium hydrogen intake characteristics satisfy certain criteria. In addition, application of first law of thermodynamics to an idealized operating cycle can provide the upper bounds of selected performance indices, namely volumetric energy storage density, energy storage efficiency and peak discharge temperature. This is demonstrated for a representative system composed of LaNi 4.7 Al 0.3 –LaNi 5 operating between 353 K and 303 K which gave values of about 56 kW h m −3 for volumetric storage density, about 85% for energy storage efficiency and 343 K for peak discharge temperature. A system level heat and mass transfer study considering the reaction kinetics, hydrogen flow between the beds and heat exchanger models is presented which gave second level estimates of about 40 kW h m −3 for volumetric energy storage density, 73% for energy storage efficiency and 334 K for peak temperature for the representative system. The results from such studies lead to identifying metal/alloy pairs which can be shortlisted for detailed studies.

Roles of texture in controlling oxidation, hydrogen ingress and hydride formation in Zr alloys

International Nuclear Information System (INIS)

Szpunar, Jerzy A.; Qin, Wen; Li, Hualong; Kumar, Kiran

2011-01-01

Experimental observations shows that the oxide formed on Zr alloys are strongly textured. The texture and grain-boundary characteristics of oxide are dependent on the texture of metal substrate. Computer simulation and thermodynamic modeling clarify the effect of metal substrate on structure of oxide film, and intrinsic factors affecting the microstructure. Models of diffusion process of hydrogen atoms and oxygen diffusion through oxide are presented. Both intra-granular and inter-granular hydrides were found following (0001) α-Zr //(111) δ-ZrH1.5 relationship. The through-thickness texture inhomogeneity in cladding tubes, the effects of hoop stress on the hydride orientation and the formation of interlinked hydride structure were studied. A thermodynamic model was developed to analyze the nucleation and the stress-induced reorientation of intergranular hydrides. These works provide a framework for understanding the oxidation, the hydrogen ingress and the hydride formation in Zr alloys. (author)

Hydrogen storage as a hydride. Citations from the International Aerospace Abstracts data base

Science.gov (United States)

Zollars, G. F.

1980-01-01

These citations from the international literature concern the storage of hydrogen in various metal hydrides. Binary and intermetallic hydrides are considered. Specific alloys discussed are iron titanium, lanthanium nickel, magnesium copper and magnesium nickel among others.

Gas atomization processing of tin and silicon modified LaNi₅ for nickel-metal hydride battery applications

Energy Technology Data Exchange (ETDEWEB)

Ting, Jason [Iowa State Univ., Ames, IA (United States)

1999-02-12

Numerous researchers have studied the relevant material properties of so-called AB₅ alloys for battery applications. These studies involved LaNi₅ substituted alloys which were prepared using conventional cast and crush alloying techniques. While valuable to the understanding of metal hydride effects, the previous work nearly ignored the potential for alternative direct powder production methods, like high pressure gas atomization (HPGA). Thus, there is a need to understand the relationship between gas atomization processes, powder particle solidification phases, and hydrogen absorption properties of ultra fine (< 25 μm) atomized powders with high surface area for enhanced battery performance. Concurrently, development of a gas atomization nozzle that is more efficient than all current designs is needed to increase the yield of ultrafine AB₅ alloy powder for further processing advantage. Gas atomization processing of the AB₅ alloys was demonstrated to be effective in producing ultrafine spherical powders that were resilient to hydrogen cycling for the benefit of improving corrosion resistance in battery application. These ultrafine powders benefited from the rapid solidification process by having refined solute segregation in the microstructure of the gas atomized powders which enabled a rapid anneal treatment of the powders. The author has demonstrated the ability to produce high yields of ultrafine powder efficiently and cost effectively, using the new HPGA-III technology. Thus, the potential benefits of processing AB₅ alloys using the new HPGA technology could reduce manufacturing cost of nickel-metal hydride powder. In the near future, the manufacture of AB₅ alloy powders could become a continuous and rapid production process. The economic benefit of an improved AB₅ production process may thereby encourage the use of nickel-metal hydride rechargeable batteries in electrical vehicle

Development of high-capacity nickel-metal hydride batteries using superlattice hydrogen-absorbing alloys

Science.gov (United States)

Yasuoka, Shigekazu; Magari, Yoshifumi; Murata, Tetsuyuki; Tanaka, Tadayoshi; Ishida, Jun; Nakamura, Hiroshi; Nohma, Toshiyuki; Kihara, Masaru; Baba, Yoshitaka; Teraoka, Hirohito

New R-Mg-Ni (R: rare earths) superlattice alloys with higher-capacity and higher-durability than the conventional Mm-Ni alloys with CaCu 5 structure have been developed. The oxidation resistibility of the superlattice alloys has been improved by optimizing the alloy composition by such as substituting aluminum for nickel and optimizing the magnesium content in order to prolong the battery life. High-capacity nickel-metal hydride batteries for the retail market, the Ni-MH2500/900 series (AA size type 2500 mAh, AAA size type 900 mAh), have been developed and commercialized by using an improved superlattice alloy for negative electrode material.

Electrolytic hydriding and hydride distribution in zircaloy-4

International Nuclear Information System (INIS)

Gomes, M.H.L.

1974-01-01

A study has been made of the electrolytic hydriding of zircaloy-4 in the range 20-80 0 C, for reaction times from 5 to 30 hours, and the effect of potential, pH and dissolved oxygen has been investigated. The hydriding reaction was more sensitive to time and temperature conditions than to the electrochemical variables. It has been shown that a controlled introduction of hydrides in zircaloy is feasible. Hydrides were found to be plate like shaped and distributed mainly along grain-boundaries. It has been shown that hydriding kinetics do not follow a simple law but may be described by a Johnson-Mehl empirical equation. On the basis of this equation an activation energy of 9.400 cal/mol has been determined, which is close to the activation energy for diffusion of hydrogen in the hydride. (author)

The effect of sample preparation on uranium hydriding

International Nuclear Information System (INIS)

Banos, A.; Stitt, C.A.; Scott, T.B.

2016-01-01

Highlights: • Distinct differences in uranium hydride growth rates and characteristics between different surface preparation methods. • The primary difference between the categories of sample preparations is the level of strain present in the surface. • Greater surface-strain, leads to higher nucleation number density, implying a preferred attack of strained vs unstrained metal. • As strain is reduced, surface features such as carbides and grain boundaries become more important in controlling the UH3 location. - Abstract: The influence of sample cleaning preparation on the early stages of uranium hydriding has been examined, by using four identical samples but concurrently prepared using four different methods. The samples were reacted together in the same corrosion cell to ensure identical exposure conditions. From the analysis, it was found that the hydride nucleation rate was proportional to the level of strain exhibiting higher number density for the more strained surfaces. Additionally, microstructure of the metal plays a secondary role regarding initial hydrogen attack on the highly strained surfaces yet starts to dominate the system while moving to more pristine samples.

Microcapsulated rare earth - nickel hydride-forming materials

International Nuclear Information System (INIS)

Ishikawa, H.; Oguro, K.; Kato, A.; Suzuki, H.; Ishii, E.

1985-01-01

Fine particles of hydride-forming alloys such as LaNi/sub 5/ and MmNi/sub 4.5/Mn/sub 0.5/ (MM : mischmetal) were coated with metallic copper thin layer by chemical plating method. Hydrogen storage capacities of alloys were not appreciably affected by the plating treatment. The capsulated alloy powders were easily pressed into pellets. The pellets obtained had high thermal conductivity and porosity enough to permeate hydrogen, leading to fast reaction kinetics. These were able to withstand more than 5,000 repeated hydriding-dehydriding cycles without disintegrating

Final report for the DOE Metal Hydride Center of Excellence.

Energy Technology Data Exchange (ETDEWEB)

Keller, Jay O.; Klebanoff, Leonard E.

2012-01-01

This report summarizes the R&D activities within the U.S. Department of Energy Metal Hydride Center of Excellence (MHCoE) from March 2005 to June 2010. The purpose of the MHCoE has been to conduct highly collaborative and multi-disciplinary applied R&D to develop new reversible hydrogen storage materials that meet or exceed DOE 2010 and 2015 system goals for hydrogen storage materials. The MHCoE combines three broad areas: mechanisms and modeling (which provide a theoretically driven basis for pursuing new materials), materials development (in which new materials are synthesized and characterized) and system design and engineering (which allow these new materials to be realized as practical automotive hydrogen storage systems). This Final Report summarizes the organization and execution of the 5-year research program to develop practical hydrogen storage materials for light duty vehicles. Major results from the MHCoE are summarized, along with suggestions for future research areas.

A review of uranium corrosion by hydrogen and the formation of uranium hydride

OpenAIRE

Banos, A.; Harker, N. J.; Scott, T. B.

2018-01-01

Uranium hydride (UH3) is the direct product of the reaction between uranium metal and gaseous hydrogen. In the context of uranium storage, this corrosion reaction is considered deleterious, not just because the structure of the metal may become significantly degraded but also because the resulting hydride is pyrophoric and therefore potentially flammable in air if present in significant quantity. The current review draws from the literature surrounding the uranium-hydrogen system accrued over...

Metal-doped sodium aluminium hydrides as potential new hydrogen storage materials

Energy Technology Data Exchange (ETDEWEB)

Bogdanovic, B. [Max-Planck-Institut fuer Kohlenforschung, Muelheim an der Ruhr (Germany); Brand, R.A. [Department of Physics, Gerhard-Mercator-Universitaet GH Duisburg, D-47048, Duisburg (Germany); Marjanovic, A.; Schwickardi, M.; Toelle, J. [Max-Planck-Institut fuer Kohlenforschung, Kaiser-Wilhelm-Platz 1, D-45470, Muelheim an der Ruhr (Germany)

2000-04-28

Thermodynamics and kinetics of the reversible dissociation of metal-doped NaAlH{sub 4} as a hydrogen (or heat) storage system have been investigated in some detail. The experimentally determined enthalpies for the first (3.7 wt% of H) and the second dissociation step of Ti-doped NaAlH{sub 4} (3.0 wt% H) of 37 and 47 kJ/mol are in accordance with low and medium temperature reversible metal hydride systems, respectively. Through variation of NaAlH{sub 4} particle sizes, catalysts (dopants) and doping procedures, kinetics as well as the cyclization stability within cycle tests have been substantially improved with respect to the previous status [B. Bogdanovic, M. Schwickardi (1997)]. In particular, using combinations of Ti and Fe compounds as dopants, a cooperative (synergistic) catalytic effect of the metals Ti and Fe in enhancing rates of both de- and rehydrogenation of Ti/Fe-doped NaAlH{sub 4} within cycle tests, reaching a constant storage capacity of {proportional_to}4 wt% H{sub 2}, has been demonstrated. By means of {sup 57}Fe Moessbauer spectroscopy of the Ti/Fe-doped NaAlH{sub 4} before and throughout a cycle test, it has been ascertained that (1) during the doping procedure, nanosize metallic Fe particles are formed from the doping agent Fe(OEt){sub 2} and (2) already after the first dehydrogenation, the nanosize Fe particles with NaAlH{sub 4} present are probably transformed into an Fe-Al-alloy which throughout the cycle test remains practically unchanged. (orig.)

Method for converting uranium oxides to uranium metal

International Nuclear Information System (INIS)

Duerksen, W.K.

1988-01-01

A method for converting uranium oxide to uranium metal is described comprising the steps of heating uranium oxide in the presence of a reducing agent to a temperature sufficient to reduce the uranium oxide to uranium metal and form a heterogeneous mixture of a uranium metal product and oxide by-products, heating the mixture in a hydrogen atmosphere at a temperature sufficient to convert uranium metal in the mixture to uranium hydride, cooling the resulting uranium hydride-containing mixture to a temperature sufficient to produce a ferromagnetic transition in the uranium hydride, magnetically separating the cooled uranium hydride from the mixture, and thereafter heating the separated uranium hydride in an inert atmosphere to a temperature sufficient to convert the uranium hydride to uranium metal

Hydriding and dehydriding characteristics of small-scale DU and ZrCo beds

Energy Technology Data Exchange (ETDEWEB)

Chung, Dongyou; Lee, Jungmin; Koo, Daeseo [Korea Atomic Energy Research Institute, 989-111 Daedeokdaero, Yuseong, Daejeon 305-353 (Korea, Republic of); Chung, Hongsuk, E-mail: hschung1@kaeri.kr [Korea Atomic Energy Research Institute, 989-111 Daedeokdaero, Yuseong, Daejeon 305-353 (Korea, Republic of); Kim, Ki Hwan [Korea Atomic Energy Research Institute, 989-111 Daedeokdaero, Yuseong, Daejeon 305-353 (Korea, Republic of); Kang, Hyun-Goo; Chang, Min Ho [National Fusion Research Institute, 113 Gwahakro, Yuseong, Daejeon 305-333 (Korea, Republic of); Camp, Patrick [ITER Organization, Route de Vinon sur Verdon, 13115 Saint Paul Lez Durance (France); Jung, Ki Jung; Cho, Seungyon; Yun, Sei-Hun; Kim, Chang Shuk [National Fusion Research Institute, 113 Gwahakro, Yuseong, Daejeon 305-333 (Korea, Republic of); Yoshida, Hiroshi [Fusion Science Consultant, 3288-10 Sakado-cho, Mito-shi 310-0841, Ibakaki-ken (Japan); Paek, Seungwoo; Lee, Hansoo [Korea Atomic Energy Research Institute, 989-111 Daedeokdaero, Yuseong, Daejeon 305-353 (Korea, Republic of)

2013-10-15

Highlights: • We have designed and fabricated a twosome small-scale getter bed for a comparison of ZrCo with DU on the hydriding/dehydriding properties. • We provide preliminary experimental results of our ZrCo and DU beds. -- Abstract: With the development of fusion technology, it will be necessary to store large amounts of tritium during the nuclear fusion fuel cycle. Stable metal tritides are viewed as potential candidates for the high-density storage of tritium. Metal tritide formers offer a safe and convenient method for tritium storage. For the storage, supply, and recovery of hydrogen isotopes, zirconium cobalt (ZrCo) and depleted uranium (DU) have been extensively proposed. Thus, we have designed and fabricated two identical small-scale getter beds for a comparison of ZrCo with DU on the hydriding/dehydriding properties. After the powderization of the metals, the hydriding/dehydriding performance at different stoichiometries of ZrCo and DU was measured. We provide preliminary experimental results of our ZrCo and DU beds.

Development of high-capacity nickel-metal hydride batteries using superlattice hydrogen-absorbing alloys

International Nuclear Information System (INIS)

Yasuoka, Shigekazu; Magari, Yoshifumi; Murata, Tetsuyuki; Tanaka, Tadayoshi; Ishida, Jun; Nakamura, Hiroshi; Nohma, Toshiyuki; Kihara, Masaru; Baba, Yoshitaka; Teraoka, Hirohito

2006-01-01

New R-Mg-Ni (R: rare earths) superlattice alloys with higher-capacity and higher-durability than the conventional Mm-Ni alloys with CaCu 5 structure have been developed. The oxidation resistibility of the superlattice alloys has been improved by optimizing the alloy composition by such as substituting aluminum for nickel and optimizing the magnesium content in order to prolong the battery life. High-capacity nickel-metal hydride batteries for the retail market, the Ni-MH2500/900 series (AA size type 2500mAh, AAA size type 900mAh), have been developed and commercialized by using an improved superlattice alloy for negative electrode material. alized by using an improved superlattice alloy for negative electrode material. (author)

Technical and economic evaluation of hydrogen storage systems based on light metal hydrides

Energy Technology Data Exchange (ETDEWEB)

Jepsen, Julian

2014-07-01

-up storage systems are designed, tested and described numerically by finite elements simulation. The influence of the tank diameter on sorption rates, hydrogen capacities and temperature profiles inside the material beds is demonstrated. Key aspects for the design of future light metal hydride storage tank systems were derived from the experimental obtained results and the theoretical simulation of Li-RHC as a representative model system for RHCs.

Heat exchanger selection and design analyses for metal hydride heat pump systems

DEFF Research Database (Denmark)

Mazzucco, Andrea; Voskuilen, Tyler G.; Waters, Essene L.

2016-01-01

This study presents a design analysis for the development of highly efficient heat exchangers within stationary metal hydride heat pumps. The design constraints and selected performance criteria are applied to three representative heat exchangers. The proposed thermal model can be applied to select...... the most efficient heat exchanger design and provides outcomes generally valid in a pre-design stage. Heat transfer effectiveness is the principal performance parameter guiding the selection analysis, the results of which appear to be mildly (up to 13%) affected by the specific Nusselt correlation used....... The thermo-physical properties of the heat transfer medium and geometrical parameters are varied in the sensitivity analysis, suggesting that the length of independent tubes is the physical parameter that influences the performance of the heat exchangers the most. The practical operative regions for each...

Thermodynamics and statistical mechanics of some hydrides of the lanthanides and actinides

International Nuclear Information System (INIS)

Mintz, M.H.

1976-06-01

This work deals mainly with the thermodynamic and physical properties of the hydrides of the lanthanides and actinides. In addition, statistical models have been developed and applied to metal-hydrogen systems. A kinetic study of the uranium-hydrogen system was performed. The thermodynamic properties of the hydrides of neptunium, thorium, praseodymium, neodymium, samarium and europium were determined. In addition the samarium-europium-hydrogen ternary system was investigated. Moessbauer effect measurements of cubic neptunium hydrides were interpreted according to a model presented. A comparison. (author)

Finite difference program for calculating hydride bed wall temperature profiles

International Nuclear Information System (INIS)

Klein, J.E.

1992-01-01

A QuickBASIC finite difference program was written for calculating one dimensional temperature profiles in up to two media with flat, cylindrical, or spherical geometries. The development of the program was motivated by the need to calculate maximum temperature differences across the walls of the Tritium metal hydrides beds for thermal fatigue analysis. The purpose of this report is to document the equations and the computer program used to calculate transient wall temperatures in stainless steel hydride vessels. The development of the computer code was motivated by the need to calculate maximum temperature differences across the walls of the hydrides beds in the Tritium Facility for thermal fatigue analysis

Clean Grain Boundary Found in C14/Body-Center-Cubic Multi-Phase Metal Hydride Alloys

Directory of Open Access Journals (Sweden)

Hao-Ting Shen

2016-06-01

Full Text Available The grain boundaries of three Laves phase-related body-center-cubic (bcc solid-solution, metal hydride (MH alloys with different phase abundances were closely examined by scanning electron microscopy (SEM, transmission electron microscopy (TEM, and more importantly, electron backscatter diffraction (EBSD techniques. By using EBSD, we were able to identify the alignment of the crystallographic orientations of the three major phases in the alloys (C14, bcc, and B2 structures. This finding confirms the presence of crystallographically sharp interfaces between neighboring phases, which is a basic assumption for synergetic effects in a multi-phase MH system.

Syntheses and properties of several metastable and stable hydrides derived from intermetallic compounds under high hydrogen pressure

Energy Technology Data Exchange (ETDEWEB)

Filipek, S.M., E-mail: sfilipek@unipress.waw.pl [Institute of High Pressure Physics PAS, ul. Sokolowska 29, 01-142 Warsaw (Poland); Paul-Boncour, V. [ICMPE-CMTR, CNRS-UPEC, 2-8 rue Henri Dunant, 94320 Thiais (France); Liu, R.S. [Department of Chemistry, National Taiwan University, Taipei 106, Taiwan (China); Jacob, I. [Unit Nuclear Eng., Ben Gurion University of the Negev, Beer-Sheva (Israel); Tsutaoka, T. [Dept. of Sci. Educ., Grad. School of Educ., Hiroshima University, Hiroshima (Japan); Budziak, A. [Institute of Nuclear Physics PAS, 31-342 Kraków (Poland); Morawski, A. [Institute of High Pressure Physics PAS, ul. Sokolowska 29, 01-142 Warsaw (Poland); Sugiura, H. [Yokohama City University, 22-2 Seto, Kanazawa-ku, Yokohama 236-0027 (Japan); Zachariasz, P. [Institute of Electron Technology Cracow Division, ul. Zablocie 39, 30-701 Krakow (Poland); Dybko, K. [Institute of Physics, PAS, 02-668 Warsaw (Poland); Diduszko, R. [Tele and Radio Research Institute, ul. Ratuszowa 11, Warsaw (Poland)

2016-12-01

Brief summary of our former work on high hydrogen pressure syntheses of novel hydrides and studies of their properties is supplemented with new results. Syntheses and properties of a number of hydrides (unstable, metastable or stable in ambient conditions) derived under high hydrogen pressure from intermetallic compounds, like MeT{sub 2}, MeNi{sub 5}, Me{sub 7}T{sub 3}, Y{sub 6}Mn{sub 23} and YMn{sub 12} (where Me = zirconium, yttrium or rare earth; T = transition metal) are presented. Stabilization of ZrFe{sub 2}H{sub 4} due to surface phenomena was revealed. Unusual role of manganese in hydride forming processes is pointed out. Hydrogen induced phase transitions, suppression of magnetism, antiferromagnetic-ferromagnetic and metal-insulator or semimetal-metal transitions are described. Equations of state (EOS) of hydrides submitted to hydrostatic pressures up to 30 GPa are presented and discussed.

Experiences from the operation of a wind-hydrogen pilot unit

International Nuclear Information System (INIS)

Varkaraki, E.; Lymberopoulos, N.; Zoulias, E.; Kalyvas, E.; Christodoulou, C.; Karagiorgis, G.

2006-01-01

A pilot wind-hydrogen system has been erected and tested at the wind park of the Centre for Renewable Energy Sources, near Athens, Greece, composed of an alkaline water electrolyser, metal hydride tanks for long term storage and a hydrogen compressor for filling high pressure hydrogen cylinders. The 25 kW electrolyser produces 0.45 kg/h hydrogen under 20 bar pressure, which may be compressed up to 220 bar in one stage. A small conventional tank acts as hydrogen buffer to smooth the pressure and flow variations at the compressor inlet. The metal hydride tanks have a storage capacity of 3.6 kg hydrogen and contain a LaNi5-type alloy. The preliminary results show that the hydrogen system has an overall efficiency of 58%, considering the electrical power of the wind turbine consumed by the whole plant, including utilities. (authors)

Magnesium hydrides and their phase transitions

Czech Academy of Sciences Publication Activity Database

Paidar, Václav

2016-01-01

Roč. 41, č. 23 (2016), s. 9769-9773 ISSN 0360-3199 R&D Projects: GA MŠk(CZ) LD13069 Institutional support: RVO:68378271 Keywords : hydrogen * magnesium and transition metal hydrides * crystal structure stability * displacive phase transformations Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 3.582, year: 2016

Advanced chemical hydride-based hydrogen generation/storage system for fuel cell vehicles

Energy Technology Data Exchange (ETDEWEB)

Breault, R.W.; Rolfe, J. [Thermo Power Corp., Waltham, MA (United States)

1998-08-01

Because of the inherent advantages of high efficiency, environmental acceptability, and high modularity, fuel cells are potentially attractive power supplies. Worldwide concerns over clean environments have revitalized research efforts on developing fuel cell vehicles (FCV). As a result of intensive research efforts, most of the subsystem technology for FCV`s are currently well established. These include: high power density PEM fuel cells, control systems, thermal management technology, and secondary power sources for hybrid operation. For mobile applications, however, supply of hydrogen or fuel for fuel cell operation poses a significant logistic problem. To supply high purity hydrogen for FCV operation, Thermo Power`s Advanced Technology Group is developing an advanced hydrogen storage technology. In this approach, a metal hydride/organic slurry is used as the hydrogen carrier and storage media. At the point of use, high purity hydrogen will be produced by reacting the metal hydride/organic slurry with water. In addition, Thermo Power has conceived the paths for recovery and regeneration of the spent hydride (practically metal hydroxide). The fluid-like nature of the spent hydride/organic slurry will provide a unique opportunity for pumping, transporting, and storing these materials. The final product of the program will be a user-friendly and relatively high energy storage density hydrogen supply system for fuel cell operation. In addition, the spent hydride can relatively easily be collected at the pumping station and regenerated utilizing renewable sources, such as biomass, natural, or coal, at the central processing plants. Therefore, the entire process will be economically favorable and environmentally friendly.

Current status of environmental, health, and safety issues of nickel metal-hydride batteries for electric vehicles

Energy Technology Data Exchange (ETDEWEB)

Corbus, D; Hammel, C J; Mark, J

1993-08-01

This report identifies important environment, health, and safety issues associated with nickel metal-hydride (Ni-MH) batteries and assesses the need for further testing and analysis. Among the issues discussed are cell and battery safety, workplace health and safety, shipping requirements, and in-vehicle safety. The manufacture and recycling of Ni-MH batteries are also examined. This report also overviews the ``FH&S`` issues associated with other nickel-based electric vehicle batteries; it examines venting characteristics, toxicity of battery materials, and the status of spent batteries as a hazardous waste.

Current status of environmental, health, and safety issues of nickel metal-hydride batteries for electric vehicles

International Nuclear Information System (INIS)

Corbus, D.; Hammel, C.J.; Mark, J.

1993-08-01

This report identifies important environment, health, and safety issues associated with nickel metal-hydride (Ni-MH) batteries and assesses the need for further testing and analysis. Among the issues discussed are cell and battery safety, workplace health and safety, shipping requirements, and in-vehicle safety. The manufacture and recycling of Ni-MH batteries are also examined. This report also overviews the ''FH ampersand S'' issues associated with other nickel-based electric vehicle batteries; it examines venting characteristics, toxicity of battery materials, and the status of spent batteries as a hazardous waste

Synthesis, properties, and assimilation methods of aluminium hydride

International Nuclear Information System (INIS)

Mirsaidov, U.M.

2013-01-01

We have discovered a new source of aluminium hydride-conversion of tetrahydrofurane under influence of halogenous alkyls. We have proposed the chlorbenzene method of synthesis of AlH 3 , which excludes adhesion and ensure high quality of the product with respect to its purity, thermal stability, habits of crystals (round shape), and granulometric composition. We determined capability of benzyl chloride to fix AlH 4 -groups by the way of complexes formation. This allows increasing efficient concentration of AlH 3 solutions and their productivity. We have carried out 'direct' crystallization of aluminium hydride in one stage using interaction of binary metal hydride with aluminium chloride in the medium of ether-toluene at 60-100 d ig C a nd using solvent distillation. In the reaction of Li H with AlCl 3 , we achieved output of pure crystal AlH 3 of hexagonal modification, which was close to quantitative. We have discovered the assimilation methods of aluminium hydride in carrying out of solid-phase chemical reactions. (author)

Modeling of electrochemical hydrogen storage in metal hydride electrodes

NARCIS (Netherlands)

Ledovskikh, A.; Danilov, D.; Vermeulen, P.; Notten, P.H.L.

2010-01-01

The recently presented electrochemical kinetic model, describing the electrochemical hydrogen storage in hydride-forming materials, was extended by the description of the solid/electrolyte interface, i.e., the charge-transfer kinetics and electrical double-layer charging. A complete set of equations

Modeling of electrochemical hydrogen storage in metal hydride electrodes

NARCIS (Netherlands)

Ledovskikh, A.; Danilov, D.; Vermeulen, P.; Notten, P.H.L.

2010-01-01

The recently presented Electrochemical Kinetic Model (EKM), describing the electrochemical hydrogen storage in hydride-forming materials, has been extended by the description of the solid/electrolyte interface, i.e. the charge transfer kinetics and electrical double layer charging. A complete set of

Corrosion behavior of Zircaloy 4 cladding material. Evaluation of the hydriding effect

International Nuclear Information System (INIS)

Blat, M.

1997-04-01

In this work, particular attention has been paid to the hydriding effect in PIE and laboratory test to validate a detrimental hydrogen contribution on Zircaloy 4 corrosion behavior at high burnup. Laboratory corrosion tests results confirm that hydrides have a detrimental role on corrosion kinetics. This effect is particularly significant for cathodic charged samples with a massive hydride outer layer before corrosion test. PIE show that at high burnup a hydride layer is formed underneath the metal/oxide interface. The results of the metallurgical examinations are discussed with respect to the possible mechanisms involved in this detrimental effect of hydrogen. Therefore, according to the laboratory tests results and PIE, hydrogen could be a strong contributor to explain the increase in corrosion rate at high burnup. (author)

Obtaining zircaloy powder through hydriding

International Nuclear Information System (INIS)

Dupim, Ivaldete da Silva; Moreira, Joao M.L.

2009-01-01

Zirconium alloys are good options for the metal matrix in dispersion fuels for power reactors due to their low thermal neutron absorption cross-section, good corrosion resistance, good mechanical strength and high thermal conductivity. A necessary step for obtaining such fuels is producing Zr alloy powder for the metal matrix composite material. This article presents results from the Zircaloy-4 hydrogenation tests with the purpose to embrittle the alloy as a first step for comminuting. Several hydrogenation tests were performed and studied through thermogravimetric analysis. They included H 2 pressures of 25 and 50 kPa and temperatures ranging between from 20 to 670 deg C. X-ray diffraction analysis showed in the hydrogenated samples the predominant presence of ZrH 2 and some ZrO 2 . Some kinetics parameters for the Zircaloy-4 hydrogenation reaction were obtained: the time required to reach the equilibrium state at the dwell temperature was about 100 minutes; the hydrogenation rate during the heating process from 20 to 670 deg C was about 21 mg/h, and at constant temperature of 670 deg C, the hydride rate was about 1.15 mg/h. The hydrogenation rate is largest during the heating process and most of it occurs during this period. After hydrogenated, the samples could easily be comminuted indicating that this is a possible technology to obtain Zircaloy powder. The results show that only few minutes of hydrogenation are necessary to reach the hydride levels required for comminuting the Zircaloy. The final hydride stoichiometry was between 2.7 and 2.8 H for each Zr atom in the sample (author)

Method for converting uranium oxides to uranium metal

Science.gov (United States)

Duerksen, Walter K.

1988-01-01

A process is described for converting scrap and waste uranium oxide to uranium metal. The uranium oxide is sequentially reduced with a suitable reducing agent to a mixture of uranium metal and oxide products. The uranium metal is then converted to uranium hydride and the uranium hydride-containing mixture is then cooled to a temperature less than -100.degree. C. in an inert liquid which renders the uranium hydride ferromagnetic. The uranium hydride is then magnetically separated from the cooled mixture. The separated uranium hydride is readily converted to uranium metal by heating in an inert atmosphere. This process is environmentally acceptable and eliminates the use of hydrogen fluoride as well as the explosive conditions encountered in the previously employed bomb-reduction processes utilized for converting uranium oxides to uranium metal.

Enhancement of Hydrogen Storage Behavior of Complex Hydrides via Bimetallic Nanocatalysts Doping

Directory of Open Access Journals (Sweden)

Prakash C. Sharma

2012-10-01

Full Text Available Pristine complex quaternary hydride (LiBH4/2LiNH2 and its destabilized counterpart (LiBH4/2LiNH2/nanoMgH2 have recently shown promising reversible hydrogen storage capacity under moderate operating conditions. The destabilization of complex hydride via nanocrystalline MgH2 apparently lowers the thermodynamic heat values and thus enhances the reversible hydrogen storage behavior at moderate temperatures. However, the kinetics of these materials is rather low and needs to be improved for on-board vehicular applications. Nanocatalyst additives such as nano Ni, nano Fe, nano Co, nano Mn and nano Cu at low concentrations on the complex hydride host structures have demonstrated a reduction in the decomposition temperature and overall increase in the hydrogen desorption reaction rates. Bi-metallic nanocatalysts such as the combination of nano Fe and nano Ni have shown further pronounced kinetics enhancement in comparison to their individual counterparts. Additionally, the vital advantage of using bi-metallic nanocatalysts is to enable the synergistic effects and characteristics of the two transitional nanometal species on the host hydride matrix for the optimized hydrogen storage behavior.

A novel magnesium-vanadium hydride synthesized by a gigapascal-high-pressure technique

Energy Technology Data Exchange (ETDEWEB)

Kyoi, Daisuke; Sato, Toyoto; Roennebro, Ewa; Tsuji, Yasufumi; Kitamura, Naoyuki; Ueda, Atsushi; Ito, Mikio; Katsuyama, Shigeru; Hara, Shigeta; Noreus, Dag; Sakai, Tetsuo

2004-07-28

A magnesium-based vanadium-doped hydride was prepared in a high-pressure anvil cell by reacting a MgH{sub 2}-25%V molar mixture at 8 GPa and 873 K. The new magnesium-vanadium hydride has a cubic F-centred substructure (a=4.721(1) Angst), with an additional superstructure, which could be described by a doubling of the cubic cell axis and a magnesium atom framework, including an ordered arrangement of both vanadium atoms and vacancies (a=9.437(3) Angst, space group Fm3-bar m (no. 225), Z=4, V=840.55 Angst{sup 3}). The metal atom structure is related to the Ca{sub 7}Ge type structure but the refined metal atom composition with vacancies on one of the magnesium sites corresponding to Mg{sub 6}V nearly in line with EDX analysis. The thermal properties of the new compound were also studied by TPD analysis and TG-DTA. The onset of the hydrogen desorption for the new Mg{sub 6}V hydride occurred at a 160 K lower temperature when compared to magnesium hydride at a heating rate of 10 K/min.

Synthesis, spectroscopy, and hydrogen/deuterium exchange in high-spin iron(II) hydride complexes.

Science.gov (United States)

Dugan, Thomas R; Bill, Eckhard; MacLeod, K Cory; Brennessel, William W; Holland, Patrick L

2014-03-03

Very few hydride complexes are known in which the metals have a high-spin electronic configuration. We describe the characterization of several high-spin iron(II) hydride/deuteride isotopologues and their exchange reactions with one another and with H2/D2. Though the hydride/deuteride signal is not observable in NMR spectra, the choice of isotope has an influence on the chemical shifts of distant protons in the dimers through the paramagnetic isotope effect on chemical shift. This provides the first way to monitor the exchange of H and D in the bridging positions of these hydride complexes. The rate of exchange depends on the size of the supporting ligand, and this is consistent with the idea that H2/D2 exchange into the hydrides occurs through the dimeric complexes rather than through a transient monomer. The understanding of H/D exchange mechanisms in these high-spin iron hydride complexes may be relevant to postulated nitrogenase mechanisms.

Predicting Hydride Donor Strength via Quantum Chemical Calculations of Hydride Transfer Activation Free Energy.

Science.gov (United States)

Alherz, Abdulaziz; Lim, Chern-Hooi; Hynes, James T; Musgrave, Charles B

2018-01-25

We propose a method to approximate the kinetic properties of hydride donor species by relating the nucleophilicity (N) of a hydride to the activation free energy ΔG ⧧ of its corresponding hydride transfer reaction. N is a kinetic parameter related to the hydride transfer rate constant that quantifies a nucleophilic hydridic species' tendency to donate. Our method estimates N using quantum chemical calculations to compute ΔG ⧧ for hydride transfers from hydride donors to CO 2 in solution. A linear correlation for each class of hydrides is then established between experimentally determined N values and the computationally predicted ΔG ⧧ ; this relationship can then be used to predict nucleophilicity for different hydride donors within each class. This approach is employed to determine N for four different classes of hydride donors: two organic (carbon-based and benzimidazole-based) and two inorganic (boron and silicon) hydride classes. We argue that silicon and boron hydrides are driven by the formation of the more stable Si-O or B-O bond. In contrast, the carbon-based hydrides considered herein are driven by the stability acquired upon rearomatization, a feature making these species of particular interest, because they both exhibit catalytic behavior and can be recycled.

Hydrogen Storage in Porous Materials and Magnesium Hydrides

NARCIS (Netherlands)

Grzech, A.

2013-01-01

In this thesis representatives of two different types of materials for potential hydrogen storage application are presented. Usage of either nanoporous materials or metal hydrides has both operational advantages and disadvantages. A main objective of this thesis is to characterize the hydrogen

Complex hydrides for hydrogen storage

Science.gov (United States)

Zidan, Ragaiy

2006-08-22

A hydrogen storage material and process of forming the material is provided in which complex hydrides are combined under conditions of elevated temperatures and/or elevated temperature and pressure with a titanium metal such as titanium butoxide. The resulting fused product exhibits hydrogen desorption kinetics having a first hydrogen release point which occurs at normal atmospheres and at a temperature between 50.degree. C. and 90.degree. C.

Mechanisms of hydrogen induced delayed cracking in hydride forming materials

International Nuclear Information System (INIS)

Dutton, R.; Nuttall, K.; Puls, M.P.; Simpson, L.A.

1977-01-01

Mechanisms which have been formulated to describe delayed hydrogen cracking in hydride-forming metals are reviewed and discussed. Particular emphasis is placed on the commercial alloy Zr--2.5% Nb (Cb) which is extensively used in nuclear reactor core components. A quantitative model for hydrogen cracking in this material is presented and compared with available experimental data. The kinetics of crack propagation are controlled by the growth of hydrides at the stressed crack tip by the diffusive ingress of hydrogen into this region. The driving force for the diffusion flux is provided by the local stress gradient which interacts with both hydrogen atoms in solution and hydrogen atoms being dissolved and reprecipitated at the crack tip. The model is developed using concepts of elastoplastic fracture mechanics. Stage I crack growth is controlled by hydrides growing in the elastic stress gradient, while Stage II is controlled by hydride growth in the plastic zone at the crack tip. Recent experimental observations are presented which indicate that the process occurs in an intermittent fashion; hydride clusters accumulate at the crack tip followed by unstable crack advance and subsequent crack arrest in repeated cycles

Mechanisms of hydrogen induced delayed cracking in hydride forming materials

International Nuclear Information System (INIS)

Dutton, R.; Nuttall, K.; Puls, M.P.; Simpson, L.A.

1977-01-01

Mechanisms which have been formulated to describe delayed hydrogen cracking in hydride-forming metals are reviewed and discussed. Particular emphasis is placed on the commercial alloy Zr-2.5 pct Nb which is extensively used in nuclear reactor core components. A quantitative model for hydrogen cracking in this material is presented and compared with available experimental data. The kinetics of crack propagation are controlled by the growth of hydrides at the stressed crack tip by the diffusive ingress of hydrogen into this region. The driving force for the diffusion flux is provided by the local stress gradient which interacts with both hydrogen atoms in solution and hydrogen atoms being dissolved and reprecipitated at the crack tip. The model is developed using concepts of elastoplastic fracture mechanics. Stage I crack growth is controlled by hydrides growing in the elastic stress gradient, while Stage II is controlled by hydride growth in the plastic zone at the crack tip. Recent experimental observations are presented which indicate that the process occurs in an intermittent fashion; hydride clusters accumulate at the crack tip followed by unstable crack advance and subsequent crack arrest in repeated cycles. 55 refs., 6 figs

Effect of variable thermal conductivity and specific heat capacity on the calculation of the critical metal hydride thickness for Ti1.1CrMn

DEFF Research Database (Denmark)

Mazzucco, Andrea; Rokni, Masoud

2014-01-01

model is applied to the metal hydride system, with Ti 1.1 CrMn as the absorbing alloy, to predict the weight fraction of absorbed hydrogen and solid bed temperat ure . Dependencies of thermal conductivity and specific heat capacity upon pressure and hydrogen content respectively , are accounted for...

Multislice simulations for in-situ HRTEM studies of nanostructured magnesium hydride at ambient hydrogen pressure

International Nuclear Information System (INIS)

Surrey, Alexander; Schultz, Ludwig; Rellinghaus, Bernd

2017-01-01

Highlights: • Multislice HRTEM contrast simulations of a windowed environmental cell. • Study of Mg and MgH2 nanocrystals as model system in hydrogen at ambient pressure. • Investigation of spatial resolution and contrast depending on specimen thickness, defocus, and hydrogen pressure. • Atomic resolution is expected for specimens as thin as 5  nm. - Abstract: The use of transmission electron microscopy (TEM) for the structural characterization of many nanostructured hydrides, which are relevant for solid state hydrogen storage, is hindered due to a rapid decomposition of the specimen upon irradiation with the electron beam. Environmental TEM allows to stabilize the hydrides by applying a hydrogen back pressure of up to 4.5 bar in a windowed environmental cell. The feasibility of high-resolution TEM (HRTEM) investigations of light weight metals and metal hydrides in such a “nanoreactor” is studied theoretically by means of multislice HRTEM contrast simulations using Mg and its hydride phase, MgH_2, as model system. Such a setup provides the general opportunity to study dehydrogenation and hydrogenation reactions at the nanoscale under technological application conditions. We analyze the dependence of both the spatial resolution and the HRTEM image contrast on parameters such as the defocus, the metal/hydride thickness, and the hydrogen pressure in order to explore the possibilities and limitations of in-situ experiments with windowed environmental cells. Such simulations may be highly valuable to pre-evaluate future experimental studies.

Multislice simulations for in-situ HRTEM studies of nanostructured magnesium hydride at ambient hydrogen pressure

Energy Technology Data Exchange (ETDEWEB)

Surrey, Alexander, E-mail: a.surrey@ifw-dresden.de [IFW Dresden, Institute for Metallic Materials, P.O. Box 270116, D-01171 Dresden (Germany); Institut für Festkörperphysik, Technische Universität Dresden, D-01062 Dresden (Germany); Schultz, Ludwig [IFW Dresden, Institute for Metallic Materials, P.O. Box 270116, D-01171 Dresden (Germany); Institut für Festkörperphysik, Technische Universität Dresden, D-01062 Dresden (Germany); Rellinghaus, Bernd, E-mail: b.rellinghaus@ifw-dresden.de [IFW Dresden, Institute for Metallic Materials, P.O. Box 270116, D-01171 Dresden (Germany)

2017-04-15

Highlights: • Multislice HRTEM contrast simulations of a windowed environmental cell. • Study of Mg and MgH2 nanocrystals as model system in hydrogen at ambient pressure. • Investigation of spatial resolution and contrast depending on specimen thickness, defocus, and hydrogen pressure. • Atomic resolution is expected for specimens as thin as 5  nm. - Abstract: The use of transmission electron microscopy (TEM) for the structural characterization of many nanostructured hydrides, which are relevant for solid state hydrogen storage, is hindered due to a rapid decomposition of the specimen upon irradiation with the electron beam. Environmental TEM allows to stabilize the hydrides by applying a hydrogen back pressure of up to 4.5 bar in a windowed environmental cell. The feasibility of high-resolution TEM (HRTEM) investigations of light weight metals and metal hydrides in such a “nanoreactor” is studied theoretically by means of multislice HRTEM contrast simulations using Mg and its hydride phase, MgH{sub 2}, as model system. Such a setup provides the general opportunity to study dehydrogenation and hydrogenation reactions at the nanoscale under technological application conditions. We analyze the dependence of both the spatial resolution and the HRTEM image contrast on parameters such as the defocus, the metal/hydride thickness, and the hydrogen pressure in order to explore the possibilities and limitations of in-situ experiments with windowed environmental cells. Such simulations may be highly valuable to pre-evaluate future experimental studies.

The Oxidation Products of Aluminum Hydride and Boron Aluminum Hydride Clusters

Science.gov (United States)

2016-01-04

AFRL-AFOSR-VA-TR-2016-0075 The Oxidation Products of Aluminum Hydride and Boron Aluminum Hydride Clusters KIT BOWEN JOHNS HOPKINS UNIV BALTIMORE MD...2. REPORT TYPE Final Performance 3. DATES COVERED (From - To) 30-09-2014 to 29-09-2015 4. TITLE AND SUBTITLE The Oxidation Products of Aluminum ...Hydride and Boron Aluminum Hydride Clusters 5a.  CONTRACT NUMBER 5b.  GRANT NUMBER FA9550-14-1-0324 5c.  PROGRAM ELEMENT NUMBER 61102F 6. AUTHOR(S) KIT

Room temperature oxidative intercalation with chalcogen hydrides: Two-step method for the formation of alkali-metal chalcogenide arrays within layered perovskites

International Nuclear Information System (INIS)

Ranmohotti, K.G. Sanjaya; Montasserasadi, M. Dariush; Choi, Jonglak; Yao, Yuan; Mohanty, Debasish; Josepha, Elisha A.; Adireddy, Shiva; Caruntu, Gabriel; Wiley, John B.

2012-01-01

Highlights: ► Topochemical reactions involving intercalation allow construction of metal chalcogenide arrays within perovskite hosts. ► Gaseous chalcogen hydrides serve as effect reactants for intercalation of sulfur and selenium. ► New compounds prepared by a two-step intercalation strategy are presented. -- Abstract: A two-step topochemical reaction strategy utilizing oxidative intercalation with gaseous chalcogen hydrides is presented. Initially, the Dion-Jacobson-type layered perovskite, RbLaNb 2 O 7 , is intercalated reductively with rubidium metal to make the Ruddlesden-Popper-type layered perovskite, Rb 2 LaNb 2 O 7 . This compound is then reacted at room-temperature with in situ generated H 2 S gas to create Rb-S layers within the perovskite host. Rietveld refinement of X-ray powder diffraction data (tetragonal, a = 3.8998(2) Å, c = 15.256(1) Å; space group P4/mmm) shows the compound to be isostructural with (Rb 2 Cl)LaNb 2 O 7 where the sulfide resides on a cubic interlayer site surrounded by rubidium ions. The mass increase seen on sulfur intercalation and the refined S site occupation factor (∼0.8) of the product indicate a higher sulfur content than expected for S 2− alone. This combined with the Raman studies, which show evidence for an H-S stretch, indicate that a significant fraction of the intercalated sulfide exists as hydrogen sulfide ion. Intercalation reactions with H 2 Se (g) were also carried out and appear to produce an isostructural selenide compound. The utilization of such gaseous hydride reagents could significantly expand multistep topochemistry to a larger number of intercalants.

Alloys for hydrogen storage in nickel/hydrogen and nickel/metal hydride batteries

Science.gov (United States)

Anani, Anaba; Visintin, Arnaldo; Petrov, Konstantin; Srinivasan, Supramaniam; Reilly, James J.; Johnson, John R.; Schwarz, Ricardo B.; Desch, Paul B.

1993-01-01

Since 1990, there has been an ongoing collaboration among the authors in the three laboratories to (1) prepare alloys of the AB(sub 5) and AB(sub 2) types, using arc-melting/annealing and mechanical alloying/annealing techniques; (2) examine their physico-chemical characteristics (morphology, composition); (3) determine the hydrogen absorption/desorption behavior (pressure-composition isotherms as a function of temperature); and (4) evaluate their performance characteristics as hydride electrodes (charge/discharge, capacity retention, cycle life, high rate capability). The work carried out on representative AB(sub 5) and AB(sub 2) type modified alloys (by partial substitution or with small additives of other elements) is presented. The purpose of the modification was to optimize the thermodynamics and kinetics of the hydriding/dehydriding reactions and enhance the stabilities of the alloys for the desired battery applications. The results of our collaboration, to date, demonstrate that (1) alloys prepared by arc melting/annealing and mechanical alloying/annealing techniques exhibit similar morphology, composition and hydriding/dehydriding characteristics; (2) alloys with the appropriate small amounts of substituent or additive elements: (1) retain the single phase structure, (2) improve the hydriding/dehydriding reactions for the battery applications, and (3) enhance the stability in the battery environment; and (3) the AB(sub 2) type alloys exhibit higher energy densities than the AB(sub 5) type alloys but the state-of-the-art, commercialized batteries are predominantly manufactured using Ab(sub 5) type alloys.

Mechanochemical synthesis of nanostructured chemical hydrides in hydrogen alloying mills

International Nuclear Information System (INIS)

Wronski, Z.; Varin, R.A.; Chiu, C.; Czujko, T.; Calka, A.

2007-01-01

Mechanical alloying of magnesium metal powders with hydrogen in specialized hydrogen ball mills can be used as a direct route for mechanochemical synthesis of emerging chemical hydrides and hydride mixtures for advanced solid-state hydrogen storage. In the 2Mg-Fe system, we have successfully synthesized the ternary complex hydride Mg 2 FeH 6 in a mixture with nanometric Fe particles. The mixture of complex magnesium-iron hydride and nano-iron released 3-4 wt.%H 2 in a thermally programmed desorption experiment at the range 285-295 o C. Milling of the Mg-2Al powder mixture revealed a strong competition between formation of the Al(Mg) solid solution and the β-MgH 2 hydride. The former decomposes upon longer milling as the Mg atoms react with hydrogen to form the hydride phase, and drive the Al out of the solid solution. The mixture of magnesium dihydride and nano-aluminum released 2.1 wt.%H 2 in the temperature range 329-340 o C in the differential scanning calorimetry experiment. The formation of MgH 2 was suppressed in the Mg-B system; instead, a hydrogenated amorphous phase (Mg,B)H x , was formed in a mixture with nanometric MgB 2 . Annealing of the hydrogen-stabilized amorphous mixture produced crystalline MgB 2

Modifications of the hydriding kinetics of a metallic surface, using ion implantation

International Nuclear Information System (INIS)

Crusset, D.

1992-10-01

Uranium reacts with hydrogen to form an hydride: this reaction leads to the total destruction of the material. To modify the reactivity of an uranium surface towards hydrogen, ion implantation was selected, among surface treatments techniques. Four elements (carbon, nitrogen, oxygen, sulfur) were implanted to different doses. The results show a modification of the hydriding mechanism and a significant increase in the reaction induction times, notably at high implantation doses. Several techniques (SIMS, X-rays phases analysis and residual stresses determination) were used to characterize the samples and understand the different mechanisms involved

Transmission Electron Microscopy Studies on Titanium-doped Sodium Aluminum Hydride

Science.gov (United States)

Culnane, Lance F.

Hydrogen fuel cells play an important role in today's diverse and blossoming alternative energy industry. One of the greatest technological barriers for vehicular applications is the storage of hydrogen (which is required to power hydrogen fuel cells). Storing hydrogen as a gas is not volume efficient, and storing it as a liquid is not cost effective, therefore solid-state storage of hydrogen, such as in metal hydrides offers the most potential for success since many metal hydrides have attractive qualities for hydrogen storage such as: high volumetric capacity, cost efficiency, weight efficiency, low refueling times, and most importantly, high safety. Unfortunately, a compound has not been discovered which contains all of the attractive hydrogen storage qualities for vehicular applications. Sodium aluminum hydride (NaAlH 4) is one of the few compounds which is close to meeting requirements for car manufacturers, and has perhaps been researched the most extensively out of all metal hydrides in the last 15 years. This arises from the remarkable discovery by Bogdanovic who found that doping NaAlH4 with Ti dopants enabled the reversible dehydrogenation and hydrogenation of NaAlH 4 at mild conditions. Various evidence and theories have been proposed to suggest explanations for the enhanced kinetic effect that Ti-doping and ball-milling provide. However, the research community has not reached a consensus as to the exact role of Ti-dopants. If the role of titanium in the NaAlH4 dehydrogenation/hydrogenation mechanism could be understood, then more attractive metal hydrides could be designed. To this end, we conducted Transmission Electron Microscopy (TEM) studies to explain the role of the Ti dopants. The first known thorough particle size analysis of the NaAlH4 system was conducted, as well as TEM-EELS (Electron Energy Loss Spectroscopy), TEM-EDS (Energy Dispersive X-ray Spectroscopy), and in-situ imaging studies. Preparation methods were found to be important for the

A new ternary magnesium-titanium hydride Mg{sub 7}TiH{sub x} with hydrogen desorption properties better than both binary magnesium and titanium hydrides

Energy Technology Data Exchange (ETDEWEB)

Kyoi, Daisuke; Sato, Toyoto; Roennebro, Ewa; Kitamura, Naoyuki; Ueda, Atsushi; Ito, Mikio; Katsuyama, Shigeru; Hara, Shigeta; Noreus, Dag; Sakai, Tetsuo

2004-06-09

A magnesium based titanium doped hydride was prepared in a high-pressure anvil cell by reacting a mixture of MgH{sub 2} and TiH{sub 1.9} at 8 GPa and 873 K. The metal structure has a Ca{sub 7}Ge type structure (a=9.532(2) A, space group Fm3-barm (no. 225), Z=4, V=866.06 A{sup 3}). The refined metal atom composition Mg{sub 7}Ti was almost in line with EDS analysis. This means that the new magnesium-titanium hydride has a structure that is more related to TiH{sub 1.9} than to MgH{sub 2}. The thermal properties of the new compound were also studied by TPD analysis. The new hydride, Mg{sub 7}TiH{sub x} exhibits 5.5 mass% (x{approx}12.7) and decomposes into Mg and TiH{sub 1.9} upon releasing 4.7 mass% of hydrogen around 605 K, that is at a 130 and 220 K lower desorption temperature compared to MgH{sub 2} and TiH{sub 1.9}, respectively.

Determination of antimony by using a quartz atom trap and electrochemical hydride generation atomic absorption spectrometry

Energy Technology Data Exchange (ETDEWEB)

Menemenlioglu, Ipek; Korkmaz, Deniz [Department of Chemistry, Middle East Technical University, 06531 Ankara (Turkey); Ataman, O. Yavuz [Department of Chemistry, Middle East Technical University, 06531 Ankara (Turkey)], E-mail: ataman@metu.edu.tr

2007-01-15

The analytical performance of a miniature quartz trap coupled with electrochemical hydride generator for antimony determination is described. A portion of the inlet arm of the conventional quartz tube atomizer was used as an integrated trap medium for on-line preconcentration of electrochemically generated hydrides. This configuration minimizes transfer lines and connections. A thin-layer of electrochemical flow through cell was constructed. Lead and platinum foils were employed as cathode and anode materials, respectively. Experimental operation conditions for hydride generation as well as the collection and revolatilization conditions for the generated hydrides in the inlet arm of the quartz tube atomizer were optimized. Interferences of copper, nickel, iron, cobalt, arsenic, selenium, lead and tin were examined both with and without the trap. 3{sigma} limit of detection was estimated as 0.053 {mu}g l{sup -1} for a sample size of 6.0 ml collected in 120 s. The trap has provided 18 fold sensitivity improvement as compared to electrochemical hydride generation alone. The accuracy of the proposed technique was evaluated with two standard reference materials; Trace Metals in Drinking Water, Cat CRM-TMDW and Metals on Soil/Sediment 4, IRM-008.

High-pressure hydriding of Zircaloy

International Nuclear Information System (INIS)

Kim, Y.S.

1996-01-01

The hydriding characteristics of Zircaloy-2(Zry), sponge zirconium (as a liner on Zry plate), and crystal-bar zirconium exposed to pure H 2 at 0.1 MPa or 7 MPa and 400 C were determined in a thermogravimetric apparatus. The morphology of the hydrided specimens was also examined by optical microscopy. For all specimen types, the rate of hydriding in 7 MPa H 2 was two orders of magnitude greater than in 0.1 MPa H 2 . For Zry, uniform bulk hydriding was revealed by hydride precipitates at room temperature and on one occasion, a sunburst hydride. In addition, all specimen types exhibited a hydride surface layer. In a duplex Zry/sponge-Zr specimen, Zry is more heavily hydrided than the sponge Zr layer. (orig.)

Atomistic modeling of zirconium hydride precipitation: methodology for deriving a tight-binding potential

International Nuclear Information System (INIS)

Dufresne, Alice

2014-01-01

The zirconium-hydrogen system is of nuclear safety interest, as the hydride precipitation leads to the cladding embrittlement, which is made of zirconium-based alloys. The cladding is the first safety barrier confining the radioactive products: its integrity shall be kept during the entire fuel-assemblies life, in reactor, including accidental situation, and post-operation (transport and storage). Many uncertainties remain regarding the hydrides precipitation kinetics and the local stress impact on their precipitation. The atomic scale modeling of this system would bring clarifications on the relevant mechanisms. The usual atomistic modeling methods are based on thermo-statistic approaches, whose precision and reliability depend on the interatomic potential used. However, there was no potential allowing a rigorous study of the Zr-H system. The present work has indeed addressed this issue: a new tight-binding potential for zirconium hydrides modeling is now available. Moreover, this thesis provides a detailed manual for deriving such potentials accounting for spd hybridization, and fitted here on DFT results. This guidebook has be written in light of modeling a pure transition metal followed by a metal-covalent coupling (metallic carbides, nitrides and silicides). (author)

Hydrogen-absorbing alloys for the nickel-metal hydride battery

Energy Technology Data Exchange (ETDEWEB)

Mingming Geng; Jianwen Han; Feng Feng [University of Windsor, Ontario (Canada). Mechanical and Materials Engineering; Northwood, D.O. [University of Windsor, Ontario (Canada). Mechanical and Materials Engineering]|[Ryerson Polytechnic University, Toronto (Canada)

1998-12-31

In recent years, owing to the rapid development of portable electronic and electrical appliances, the market for rechargeable batteries has increased at a high rate. The nickel-metal hydride battery (Ni/MH) is one of the more promising types, because of its high capacity, high-rate charge/discharge capability and non-polluting nature. This type of battery uses a hydrogen storage alloy as its negative electrode. The characteristics of the Ni/MH battery, including discharge voltage, high-rate discharge capability and charge/discharge cycle lifetime are mainly determined by the construction of the negative electrode and the composition of the hydrogen-absorbing alloy. The negative electrode of the Ni/MH battery described in this paper was made from a mixture of hydrogen-absorbing alloy, nickel powder and polytetrafluoroethylene (PTFE). A multicomponent MmNi{sub 5}-based alloy (Mm{sub 0.95}Ti{sub 0.05}Ni{sub 3.85} Co{sub 0.45}Mn{sub 0.35}Al{sub 0.35}) was used as the hydrogen-absorbing alloy. The discharge characteristics of the negative electrode, including discharge capacity, cycle lifetime, and polarization overpotential, were studied by means of electrochemical experiments and analysis. The decay of the discharge capacity for the Ni/MH battery (AA size, 1 Ah) was about 1% after 100 charge/discharge cycles and 10% after 500 charge/discharge cycles. (author)

Axial-Centrifugal Compressor Program

Science.gov (United States)

1975-10-01

Assembly . .. . .... ..... 33 5 Tie Bolt...... .. .. .. .. . *.. .. .. .. .. .. ... 34 6 Axial Compressor Rotor Assembly Runouts . . .. . 34 7 CCV Blow...1.796 Impeller Slip Factor ’Ce2/U 2 ) .91 Impeller Wheel Speed ft/sec 1992.2 Impellet ’.ip Radius in. 3.780 Blade Tip Metal Angle- deg 0 Numbec of Blades...test item to the next Phase V component test. The test vehicle final balance levels and rotor runouts were normal at teardown, and no rubsI were

Optical hydrogen sensors based on metal-hydrides

Science.gov (United States)

Slaman, M.; Westerwaal, R.; Schreuders, H.; Dam, B.

2012-06-01

For many hydrogen related applications it is preferred to use optical hydrogen sensors above electrical systems. Optical sensors reduce the risk of ignition by spark formation and are less sensitive to electrical interference. Currently palladium and palladium alloys are used for most hydrogen sensors since they are well known for their hydrogen dissociation and absorption properties at relatively low temperatures. The disadvantages of palladium in sensors are the low optical response upon hydrogen loading, the cross sensitivity for oxygen and carbon, the limited detection range and the formation of micro-cracks after some hydrogen absorption/desorption cycles. In contrast to Pd, we find that the use of magnesium or rear earth bases metal-hydrides in optical hydrogen sensors allow tuning of the detection levels over a broad pressure range, while maintaining a high optical response. We demonstrate a stable detection layer for detecting hydrogen below 10% of the lower explosion limit in an oxygen rich environment. This detection layer is deposited at the bare end of a glass fiber as a micro-mirror and is covered with a thin layer of palladium. The palladium layer promotes the hydrogen uptake at room temperature and acts as a hydrogen selective membrane. To protect the sensor for a long time in air a final layer of a hydrophobic fluorine based coating is applied. Such a sensor can be used for example as safety detector in automotive applications. We find that this type of fiber optic hydrogen sensor is also suitable for hydrogen detection in liquids. As example we demonstrate a sensor for detecting a broad range of concentrations in transformer oil. Such a sensor can signal a warning when sparks inside a high voltage power transformer decompose the transformer oil over a long period.

Room temperature oxidative intercalation with chalcogen hydrides: Two-step method for the formation of alkali-metal chalcogenide arrays within layered perovskites

Energy Technology Data Exchange (ETDEWEB)

Ranmohotti, K.G. Sanjaya; Montasserasadi, M. Dariush; Choi, Jonglak; Yao, Yuan; Mohanty, Debasish; Josepha, Elisha A.; Adireddy, Shiva; Caruntu, Gabriel [Department of Chemistry and the Advanced Materials Research Institute, University of New Orleans, New Orleans, LA 70148-2820 (United States); Wiley, John B., E-mail: jwiley@uno.edu [Department of Chemistry and the Advanced Materials Research Institute, University of New Orleans, New Orleans, LA 70148-2820 (United States)

2012-06-15

Highlights: ► Topochemical reactions involving intercalation allow construction of metal chalcogenide arrays within perovskite hosts. ► Gaseous chalcogen hydrides serve as effect reactants for intercalation of sulfur and selenium. ► New compounds prepared by a two-step intercalation strategy are presented. -- Abstract: A two-step topochemical reaction strategy utilizing oxidative intercalation with gaseous chalcogen hydrides is presented. Initially, the Dion-Jacobson-type layered perovskite, RbLaNb{sub 2}O{sub 7}, is intercalated reductively with rubidium metal to make the Ruddlesden-Popper-type layered perovskite, Rb{sub 2}LaNb{sub 2}O{sub 7}. This compound is then reacted at room-temperature with in situ generated H{sub 2}S gas to create Rb-S layers within the perovskite host. Rietveld refinement of X-ray powder diffraction data (tetragonal, a = 3.8998(2) Å, c = 15.256(1) Å; space group P4/mmm) shows the compound to be isostructural with (Rb{sub 2}Cl)LaNb{sub 2}O{sub 7} where the sulfide resides on a cubic interlayer site surrounded by rubidium ions. The mass increase seen on sulfur intercalation and the refined S site occupation factor (∼0.8) of the product indicate a higher sulfur content than expected for S{sup 2−} alone. This combined with the Raman studies, which show evidence for an H-S stretch, indicate that a significant fraction of the intercalated sulfide exists as hydrogen sulfide ion. Intercalation reactions with H{sub 2}Se{sub (g)} were also carried out and appear to produce an isostructural selenide compound. The utilization of such gaseous hydride reagents could significantly expand multistep topochemistry to a larger number of intercalants.

In situ X-ray diffraction environments for high-pressure reactions

DEFF Research Database (Denmark)

R. S. Hansen, Bjarne; Møller, Kasper Trans; Paskevicius, Mark

2015-01-01

), quartz glass (SiO2), stainless steel (S316) and glassy carbon (Sigradur K), and burst pressures are calculated and tested for the different tube materials. In these studies, high hydrogen pressure is generated with a metal hydride hydrogen compressor mounted in a closed system, which allows reuse...

Tailoring Thermodynamics and Kinetics for Hydrogen Storage in Complex Hydrides towards Applications.

Science.gov (United States)

Liu, Yongfeng; Yang, Yaxiong; Gao, Mingxia; Pan, Hongge

2016-02-01

Solid-state hydrogen storage using various materials is expected to provide the ultimate solution for safe and efficient on-board storage. Complex hydrides have attracted increasing attention over the past two decades due to their high gravimetric and volumetric hydrogen densities. In this account, we review studies from our lab on tailoring the thermodynamics and kinetics for hydrogen storage in complex hydrides, including metal alanates, borohydrides and amides. By changing the material composition and structure, developing feasible preparation methods, doping high-performance catalysts, optimizing multifunctional additives, creating nanostructures and understanding the interaction mechanisms with hydrogen, the operating temperatures for hydrogen storage in metal amides, alanates and borohydrides are remarkably reduced. This temperature reduction is associated with enhanced reaction kinetics and improved reversibility. The examples discussed in this review are expected to provide new inspiration for the development of complex hydrides with high hydrogen capacity and appropriate thermodynamics and kinetics for hydrogen storage. © 2015 The Chemical Society of Japan & Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Mechanism of n-butane hydrogenolysis promoted by Ta-hydrides supported on silica

KAUST Repository

Pasha, Farhan Ahmad

2014-06-06

The mechanism of hydrogenolysis of alkanes, promoted by Ta-hydrides supported on silica via 2 ≡ Si-O- bonds, has been studied with a density functional theory (DFT) approach. Our study suggests that the initial monohydride (≡ Si-O-)2Ta(III)H is rapidly trapped by molecular hydrogen to form the more stable tris-hydride (≡ Si-O-) 2Ta(V)H3. Loading of n-butane to the Ta-center occurs through C-H activation concerted with elimination of molecular hydrogen (σ-bond metathesis). Once the Ta-alkyl species is formed, the C-C activation step corresponds to a β-alkyl transfer to the metal with elimination of an olefin. According to these calculations, an α-alkyl transfer to the metal to form a Ta-carbene species is of higher energy. The olefins formed during the C-C activation step can be rapidly hydrogenated by both mono- and tris-Ta-hydride species, making the overall process of alkane cracking thermodynamically favored. © 2014 American Chemical Society.

The effect of hydrides on the growth of zirconia

International Nuclear Information System (INIS)

Ekbom, L.R.

1982-01-01

The purpose of the present experiment has been to verify a hypothesis that accelerated corrosion of hydride containin Zircaloy is caused by small pores formed in the oxide by the evolution of hydrogen during oxidation of hydrides. The work has been divided into two parts: specimen preparation and microscopy. ZrO 2 is difficult to work with because of the high compressive stress which exists in the oxide. The most interesting area to study if any hydrogen pores exist, is the metal-oxide interface. Both transmission and scanning electron microscopy were used in the study. Neither of these methods gave any useful information with regard to the original hypothesis. However, a few interesting observations were made on the structure of the oxide at the metal-oxide interface. When the metal had been removed by electropolishing it was seen that the inner surface of the oxide consisted of 0,2-0.3 μ long and 0.1 μ thick wormlike protuberances of oxide. These features could not be seen when the metal had been removed by chemical etching. An attempt to determine whether or not this structure is an artefact introduced by electropolishing was inconclusive but indicated that the structure probably is real. (Author)

Rare earth metals, rare earth hydrides, and rare earth oxides as thin films

International Nuclear Information System (INIS)

Gasgnier, M.

1980-01-01

The review deals with pure rare earth materials such as rare earth metals, rare earth hydrides, and rare earth oxides as thin films. Several preparation techniques, control methods, and nature of possible contaminations of thin films are described. These films can now be produced in an extremely well-known state concerning chemical composition, structure and texture. Structural, electric, magnetic, and optical properties of thin films are studied and discussed in comparison with the bulk state. The greatest contamination of metallic rare earth thin films is caused by reaction with hydrogen or with water vapour. The compound with an f.c.c. structure is the dihydride LnH 2 (Ln = lanthanides). The oxygen contamination takes place after annealing at higher temperatures. Then there appears a compound with a b.c.c. structure which is the C-type sesquioxide C-Ln 2 O 3 . At room atmosphere dihydride light rare earth thin films are converted to hydroxide Ln(OH) 3 . For heavy rare earth thin films the oxinitride LnNsub(x)Osub(y) is observed. The LnO-type compound was never seen. The present review tries to set the stage anew for the investigations to be undertaken in the future especially through the new generations of electron microscopes

An anti CuO{sub 2}-type metal hydride square net structure in Ln{sub 2}M{sub 2}As{sub 2}H{sub x} (Ln = La or Sm, M = Ti, V, Cr, or Mn)

Energy Technology Data Exchange (ETDEWEB)

Mizoguchi, Hiroshi; Park, SangWon; Hosono, Hideo [Tokyo Institute of Technology, Yokohama (Japan). Materials Research Center for Element Strategy; Hiraka, Haruhiro; Ikeda, Kazutaka; Otomo, Toshiya [High-Energy Accelerator Research Organization (KEK), Tsukuba (Japan). Inst. of Materials Structure Science

2015-03-02

Using a high pressure technique and the strong donating nature of H{sup -}, a new series of tetragonal La{sub 2}Fe{sub 2}Se{sub 2}O{sub 3}-type layered mixed-anion arsenides, Ln{sub 2}M{sub 2}As{sub 2}H{sub x}, was synthesized (Ln=La or Sm, M=Ti, V, Cr, or Mn; x∼3). In these compounds, an unusual M{sub 2}H square net, which has anti CuO{sub 2} square net structures accompanying two As{sup 3-} ions, is sandwiched by (LaH){sub 2} fluorite layers. Notably, strong metal-metal bonding with a distance of 2.80 Aa was confirmed in La{sub 2}Ti{sub 2}As{sub 2}H{sub 2.3}, which has metallic properties. In fact, these compounds are situated near the boundary between salt-like ionic hydrides and transition-metal hydrides with metallic characters.

Multi-scale characterization of nanostructured sodium aluminum hydride

Science.gov (United States)

NaraseGowda, Shathabish

Complex metal hydrides are the most promising candidate materials for onboard hydrogen storage. The practicality of this class of materials is counter-poised on three critical attributes: reversible hydrogen storage capacity, high hydrogen uptake/release kinetics, and favorable hydrogen uptake/release thermodynamics. While a majority of modern metallic hydrides that are being considered are those that meet the criteria of high theoretical storage capacity, the challenges lie in addressing poor kinetics, thermodynamics, and reversibility. One emerging strategy to resolve these issues is via nanostructuring or nano-confinement of complex hydrides. By down-sizing and scaffolding them to retain their nano-dimensions, these materials are expected to improve in performance and reversibility. This area of research has garnered immense interest lately and there is active research being pursued to address various aspects of nanostructured complex hydrides. The research effort documented here is focused on a detailed investigation of the effects of nano-confinement on aspects such as the long range atomic hydrogen diffusivities, localized hydrogen dynamics, microstructure, and dehydrogenation mechanism of sodium alanate. A wide variety of microporous and mesoporous materials (metal organic frameworks, porous silica and alumina) were investigated as scaffolds and the synthesis routes to achieve maximum pore-loading are discussed. Wet solution infiltration technique was adopted using tetrahydrofuran as the medium and the precursor concentrations were found to have a major role in achieving maximum pore loading. These concentrations were optimized for each scaffold with varying pore sizes and confinement was quantitatively characterized by measuring the loss in specific surface area. This work is also aimed at utilizing neutron and synchrotron x-ray characterization techniques to study and correlate multi-scale material properties and phenomena. Some of the most advanced

Failure of the CAPS compressor(s). Final unusual occurrence report

International Nuclear Information System (INIS)

Kuechle, J.D.

1981-01-01

Acceptance testing of the CAPS compressors (4) was in progress which required periodic running of these units. Some vibration problems had occurred which required compressor shutdown for visual inspection and repair. During the performance of this visual inspection, it was decided to remove the crank case covers and to inspect the lower section of the cylinder liners for wear. The inspection revealed excessive scoring of the vertical cylinder liners on two of the four compressors that were opened. Acceptance testing of the CAPS compressors was suspended, pending further evaluation and repair

Influence of hydrides orientation on strain, damage and failure of hydrided zircaloy-4

International Nuclear Information System (INIS)

Racine, A.

2005-09-01

In pressurized water reactors of nuclear power plants, fuel pellets are contained in cladding tubes, made of Zirconium alloy, for instance Zircaloy-4. During their life in the primary water of the reactor (155 bars, 300 C), cladding tubes are oxidized and consequently hydrided. A part of the hydrogen given off precipitates as Zirconium hydrides in the bulk material and embrittles the material. This embrittlement depends on many parameters, among which hydrogen content and orientation of hydrides with respect to the applied stress. This investigation is devoted to the influence of the orientation of hydrides with respect to the applied stress on strain, damage and failure mechanisms. Macroscopic and SEM in-situ ring tensile tests are performed on cladding tube material (unirradiated cold worked stress-relieved Zircaloy-4) hydrided with about 200 and 500 wppm hydrogen, and with different main hydrides orientation: either parallel or perpendicular to the circumferential tensile direction. We get the mechanical response of the material as a function of hydride orientation and hydrogen content and we investigate the deformation, damage and failure mechanisms. In both cases, digital image correlation techniques are used to estimate local and global strain distributions. Neither the tensile stress-strain response nor the global and local strain modes are significantly affected by hydrogen content or hydride orientation, but the failure modes are strongly modified. Indeed, only 200 wppm radial hydrides embrittle Zy-4: sample fail in the elastic domain at about 350 MPa before strain bands could develop; whereas in other cases sample reach at least 750 MPa before necking and final failure, in ductile or brittle mode. To model this particular heterogeneous material behavior, a non-coupled damage approach which takes into account the anisotropic distribution of the hydrides is proposed. Its parameters are identified from the macroscopic strain field measurements and a

Hydride heat pump. Volume I. Users manual for HYCSOS system design program. [HYCSOS code

Energy Technology Data Exchange (ETDEWEB)

Gorman, R.; Moritz, P.

1978-05-01

A method for the design and costing of a metal hydride heat pump for residential use and a computer program, HYCSOS, which automates that method are described. The system analyzed is one in which a metal hydride heat pump can provide space heating and space cooling powered by energy from solar collectors and electric power generated from solar energy. The principles and basic design of the system are presented, and the computer program is described giving detailed design and performance equations used in the program. The operation of the program is explained, and a sample run is presented. This computer program is part of an effort to design, cost, and evaluate a hydride heat pump for residential use. The computer program is written in standard Fortran IV and was run on a CDC Cyber 74 and Cyber 174 computer. A listing of the program is included as an appendix. This report is Volume 1 of a two-volume document.

Centrifugal Compressor Unit-based Heat Energy Recovery at Compressor Stations

Directory of Open Access Journals (Sweden)

V. S. Shadrin

2016-01-01

Full Text Available About 95% of the electricity consumed by air compressor stations around the world, is transformed into thermal energy, which is making its considerable contribution to global warming. The present article dwells on the re-use (recovery of energy expended for air compression.The article presents the energy analysis of the process of compressing air from the point of view of compressor drive energy conversion into heat energy. The temperature level of excess heat energy has been estimated in terms of a potential to find the ways of recovery of generated heat. It is shown that the temperature level formed by thermal energy depends on the degree of air compression and the number of stages of the compressor.Analysis of technical characteristics of modern equipment from leading manufacturers, as well as projects of the latest air compressor stations have shown that there are two directions for the recovery of heat energy arising from the air compression: Resolving technological problems of compressor units. The use of the excess heat generation to meet the technology objectives of the enterprise. This article examines the schematic diagrams of compressor units to implement the idea of heat recovery compression to solve technological problems: Heating of the air in the suction line during operation of the compressor station in winter conditions. Using compression heat to regenerate the adsorbent in the dryer of compressed air.The article gives an equity assessment of considered solutions in the total amount of heat energy of compressor station. Presented in the present work, the analysis aims to outline the main vectors of technological solutions that reduce negative impacts of heat generation of compressor stations on the environment and creating the potential for reuse of energy, i.e. its recovery.

Metal hydride and pyrophoric fuel additives for dicyclopentadiene based hybrid propellants

Science.gov (United States)

Shark, Steven C.

The purpose of this study is to investigate the use of reactive energetic fuel additives that have the potential to increase the combustion performance of hybrid rocket propellants in terms of solid fuel regression rate and combustion efficiency. Additives that can augment the combustion flame zone in a hybrid rocket motor by means of increased energy feedback to the fuel grain surface are of great interest. Metal hydrides have large volumetric hydrogen densities, which gives these materials high performance potential as fuel additives in terms of specifc impulse. The excess hydrogen and corresponding base metal may also cause an increase in the hybrid rocket solid fuel regression rate. Pyrophoric additives also have potential to increase the solid fuel regression rate by reacting more readily near the burning fuel surface providing rapid energy feedback. An experimental performance evaluation of metal hydride fuel additives for hybrid rocket motor propulsion systems is examined in this study. Hypergolic ignition droplet tests and an accelerated aging study revealed the protection capabilities of Dicyclopentadiene (DCPD) as a fuel binder, and the ability for unaided ignition. Static hybrid rocket motor experiments were conducted using DCPD as the fuel. Sodium borohydride (NabH4) and aluminum hydride (AlH3) were examined as fuel additives. Ninety percent rocket grade hydrogen peroxide (RGHP) was used as the oxidizer. In this study, the sensitivity of solid fuel regression rate and characteristic velocity (C*) efficiency to total fuel grain port mass flux and particle loading is examined. These results were compared to HTPB combustion performance as a baseline. Chamber pressure histories revealed steady motor operation in most tests, with reduced ignition delays when using NabH4 as a fuel additive. The addition of NabH4 and AlH3 produced up to a 47% and 85% increase in regression rate over neat DCPD, respectively. For all test conditions examined C* efficiency ranges

A New Class of Atomically Precise, Hydride-Rich Silver Nanoclusters Co-Protected by Phosphines

KAUST Repository

Bootharaju, Megalamane Siddaramappa

2016-10-10

Thiols and phosphines are the most widely used organic ligands to attain atomically precise metal nanoclusters (NCs). Here, we used simple hydrides (e.g., H–) as ligands along with phosphines, such as triphenylphosphine (TPP), 1,2-bis(diphenylphosphino)ethane [DPPE], and tris(4-fluorophenyl)phosphine [TFPP] to design and synthesize a new class of hydride-rich silver NCs. This class includes [Ag18H16(TPP)10]2+, [Ag25H22(DPPE)8]3+, and [Ag26H22(TFPP)13]2+. Our work reveals a new family of atomically precise NCs protected by H– ligands and labile phosphines, with potentially more accessible active metal sites for functionalization and provides a new set of stable NC sizes with simpler ligand–metal bonding for researchers to explore both experimentally and computationally.

High ratio recirculating gas compressor

Science.gov (United States)

Weinbrecht, J.F.

1989-08-22

A high ratio positive displacement recirculating rotary compressor is disclosed. The compressor includes an integral heat exchanger and recirculation conduits for returning cooled, high pressure discharge gas to the compressor housing to reducing heating of the compressor and enable higher pressure ratios to be sustained. The compressor features a recirculation system which results in continuous and uninterrupted flow of recirculation gas to the compressor with no direct leakage to either the discharge port or the intake port of the compressor, resulting in a capability of higher sustained pressure ratios without overheating of the compressor. 10 figs.

Leak-tight compressor

International Nuclear Information System (INIS)

Bogomolova, L.K.; Vasilenko, A.T.

1974-01-01

The publication describes the construction and operating principle of the sealed uniflow compressor. This compressor insures against substantial contamination of the medium handled. Use of the slot-type sealing of the piston and rejection of the sliding bearings result in insuring high purity of the medium handled. The compressor performance is as follows: maximum air throughput - 262.6 1/h at 24 deg C and absolute outlet pressure being 1.14 kgf/cm 2 , minimum air throughput - 82.6 1/h at 24 deg C and absolute outlet pressure being 1.4 kgf/cm 2 ; inlet pressure equals 1 kgf/cm 2 . The compressor is provided with a solenoid-operated drive. The prototype has been in service for 6 months, with accumulated service time amounting to 500 h. The compressor has given a good account of itself within this period. The compressor is to be used in the gas purification circuit when this gas is used as a working medium in the spark or streamer chambers

An anti CuO{sub 2}-type metal hydride square net structure in Ln{sub 2}M{sub 2}As{sub 2}H{sub x} (Ln = La or Sm, M = Ti, V, Cr, or Mn)

Energy Technology Data Exchange (ETDEWEB)

Mizoguchi, Hiroshi; Park, SangWon; Hosono, Hideo [Materials Research Center for Element Strategy, Tokyo Institute of Technology, Yokohama 226-8503 (Japan); Hiraka, Haruhiro; Ikeda, Kazutaka; Otomo, Toshiya [Institute of Materials Structure Science, High-Energy Accelerator Research Organization (KEK), Tsukuba 305-0801 (Japan)

2015-03-02

Using a high pressure technique and the strong donating nature of H{sup -}, a new series of tetragonal La{sub 2}Fe{sub 2}Se{sub 2}O{sub 3}-type layered mixed-anion arsenides, Ln{sub 2}M{sub 2}As{sub 2}H{sub x}, was synthesized (Ln=La or Sm, M=Ti, V, Cr, or Mn; x∼3). In these compounds, an unusual M{sub 2}H square net, which has anti CuO{sub 2} square net structures accompanying two As{sup 3-} ions, is sandwiched by (LaH){sub 2} fluorite layers. Notably, strong metal-metal bonding with a distance of 2.80 Aa was confirmed in La{sub 2}Ti{sub 2}As{sub 2}H{sub 2.3}, which has metallic properties. In fact, these compounds are situated near the boundary between salt-like ionic hydrides and transition-metal hydrides with metallic characters. (copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Comminution of the U-10Mo by hydriding cycles innovative process

Energy Technology Data Exchange (ETDEWEB)

Faeda, Kelly C.M.; Santos, Ana Maria M. dos; Paula, Joao B. de; Pereira, Edilson M.; Pedrosa, Tercio A.; Lameiras, Fernando S.; Ferraz, Wilmar B., E-mail: ferrazw@cdtn.br, E-mail: kelly.faeda@prof.una.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

2013-07-01

The research, test and producing radioisotopes compact reactors were developed with the use of high levels of enriched fuel of approximately 90% of the fissile isotope U-235. Since the 80s', a policy under the context of international program RERTR (Reduced Enrichment for Research and Test Reactors) encourages the fuel replacement of the high enriched fuel by the low one of about 20 % U-235. One way to compensate the substitution for the low enrichment fuel is to employ high density metal uranium alloys. The fabrication of compact reactor fuel uses the metal matrix dispersion and, for this, uranium alloys are used in the form of powders. Despite the high densities, the metallic uranium based alloys are ductile and therefore difficult to be comminuted. Among the different comminution processes, the hydriding-dehydriding process has proved most advantageous, primarily due to their relative simplicity of processing and low manufacturing cost. In this paper, we present the results of the development of the U-10Mo alloy comminution process by the hydriding-dehydriding method on a laboratory scale. Samples of the alloy were subjected to different hydriding cycle numbers in order to verify its influence in relation to the particle size distribution of powders. Powders of different particle sizes were obtained and characterized by the physical and morphological characteristics by optical microscopy, scanning electron microscopy and X ray diffraction. The obtained results are evaluated and discussed. (author)

Investigation of the thermodynamics governing metal hydride synthesis in the molten state process

International Nuclear Information System (INIS)

Stowe, Ashley C.; Berseth, Polly A.; Farrell, Thomas P.; Laughlin, Laura; Anton, Donald; Zidan, Ragaiy

2008-01-01

This work is aimed at utilizing a new synthetic technique to form novel complex hydrides for hydrogen storage. This technique is based on fusing different complex hydrides at elevated temperatures and pressures to form new species with improved hydrogen storage properties. Under conditions of elevated hydrogen overpressures and temperatures the starting materials can reach melting or near-melting point without decomposing (molten state processing), allowing for enhanced diffusion and exchange of elements among the starting materials. The formation and stabilization of these compounds, using the molten state process, is driven by the thermodynamic and kinetic properties of the starting and resulting compounds. Complex hydrides (e.g. NaK 2 AlH 6 , Mg(AlH 4 ) 2 ) were formed, structurally characterized and their hydrogen desorption properties were tested. In this paper we report on investigations of the thermodynamic aspects governing the process and products. We also report on the role of molar ratio in determining the final products. The effectiveness of the molten state process is compared with chemomechanical synthetic methods (ball milling)

Zirconium hydride containing explosive composition

Science.gov (United States)

Walker, Franklin E.; Wasley, Richard J.

1981-01-01

An improved explosive composition is disclosed and comprises a major portion of an explosive having a detonation velocity between about 1500 and 10,000 meters per second and a minor amount of a donor additive comprising a non-explosive compound or mixture of non-explosive compounds which when subjected to an energy fluence of 1000 calories/cm.sup.2 or less is capable of releasing free radicals each having a molecular weight between 1 and 120. Exemplary donor additives are dibasic acids, polyamines and metal hydrides.

Gas desorption properties of ammonia borane and metal hydride composites

International Nuclear Information System (INIS)

Matin, M.R.

2009-01-01

'Full text': Ammonia borane (NH 3 BH 3 ) has been of great interest owing to its ideal combination of low molecular weight and high H 2 storage capacity of 19.6 mass %, which exceeds the current capacity of gasoline. DOE's year 2015 targets involve gravimetric as well as volumetric energy densities. In this work, we have investigated thermal decomposition of ammonia borane and calcium hydride composites at different molar ratio. The samples were prepared by planetary ball milling under hydrogen gas atmosphere pressure of 1Mpa at room temperature for 2, and 10 hours. The gas desorption properties were examined by thermal desorption mass spectroscopy (TDMS). The identification of phases was carried out by X-ray diffraction. The results obtain were shown in fig (a),(b),and (c). Hydrogen desorption properties were observed at all molar ratios, but the desorption temperature is significantly lower at around 70 o C at molar ratio 1:1 as shown in fig (c), and unwanted gas (ammonia) emissions were remarkably suppressed by mixing with the calcium hydride. (author)

Hydride embrittlement in zircaloy components

Energy Technology Data Exchange (ETDEWEB)

Lobo, Raquel M.; Andrade, Arnaldo H.P.; Castagnet, Mariano, E-mail: rmlobo@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

2011-07-01

Zirconium alloys are used in nuclear reactor cores under high-temperature water environment. During service, hydrogen is generated by corrosion processes, and it is readily absorbed by these materials. When hydrogen concentration exceeds the terminal solid solubility, the excess hydrogen precipitates as zirconium hydride (ZrH{sub 2}) platelets or needles. Zirconium alloys components can fail by hydride cracking if they contain large flaws and are highly stressed. Zirconium alloys are susceptible to a mechanism for crack initiation and propagation termed delayed hydride cracking (DHC). The presence of brittle hydrides, with a K{sub Ic} fracture toughness of only a few MPa{radical}m, results in a severe loss in ductility and toughness when platelet normal is oriented parallel to the applied stress. In plate or tubing, hydrides tend to form perpendicular to the thickness direction due to the texture developed during fabrication. Hydrides in this orientation do not generally cause structural problems because applied stresses in the through-thickness direction are very low. However, the high mobility of hydrogen in a zirconium lattice enables redistribution of hydrides normal to the applied stress direction, which can result in localized embrittlement. When a platelet reaches a critical length it ruptures. If the tensile stress is sufficiently great, crack initiation starts at some of these hydrides. Crack propagation occurs by repeating the same process at the crack tip. Delayed hydride cracking can degrade the structural integrity of zirconium alloys during reactor service. The paper focuses on the fracture mechanics and fractographic aspects of hydride material. (author)

Miniature Centrifugal Compressor

Science.gov (United States)

Sixsmith, Herbert

1989-01-01

Miniature turbocompressor designed for reliability and long life. Cryogenic system includes compressor, turboexpander, and heat exchanger provides 5 W of refrigeration at 70 K from 150 W input power. Design speed of machine 510,000 rpm. Compressor has gas-lubricated journal bearings and magnetic thrust bearing. When compressor runs no bearing contact and no wear.

Rare earth element recycling from waste nickel-metal hydride batteries.

Science.gov (United States)

Yang, Xiuli; Zhang, Junwei; Fang, Xihui

2014-08-30

With an increase in number of waste nickel-metal hydride batteries, and because of the importance of rare earth elements, the recycling of rare earth elements is becoming increasingly important. In this paper, we investigate the effects of temperature, hydrochloric acid concentration, and leaching time to optimize leaching conditions and determine leach kinetics. The results indicate that an increase in temperature, hydrochloric acid concentration, and leaching time enhance the leaching rate of rare earth elements. A maximum rare earth elements recovery of 95.16% was achieved at optimal leaching conditions of 70°C, solid/liquid ratio of 1:10, 20% hydrochloric acid concentration, -74μm particle size, and 100min leaching time. The experimental data were best fitted by a chemical reaction-controlled model. The activation energy was 43.98kJ/mol and the reaction order for hydrochloric acid concentration was 0.64. The kinetic equation for the leaching process was found to be: 1-(1-x)(1/3)=A/ρr0[HCl](0.64)exp-439,8008.314Tt. After leaching and filtration, by adding saturated oxalic solution to the filtrate, rare earth element oxalates were obtained. After removing impurities by adding ammonia, filtering, washing with dilute hydrochloric acid, and calcining at 810°C, a final product of 99% pure rare earth oxides was obtained. Copyright © 2014 Elsevier B.V. All rights reserved.

Mechanical properties and fracture of titanium hydrides

International Nuclear Information System (INIS)

Koketsu, Hideyuki; Taniyama, Yoshihiro; Yonezu, Akio; Cho, Hideo; Ogawa, Takeshi; Takemoto, Mikio; Nakayama, Gen

2006-01-01

Titanium hydrides tend to suffer fracture when their thicknesses reach a critical thickness. Morphology and mechanical property of the hydrides are, however, not well known. The study aims to reveal the hydride morphology and fracture types of the hydrides. Chevron shaped plate hydrides were found to be produced on the surface of pure titanium (Grade 1) and Grade 7 titanium absorbing hydrogen. There were tree types of fracture of the hydrides, i.e., crack in hydride layer, exfoliation of the layer and shear-type fracture of the hydride plates, during the growth of the hydrides and deformation. We next estimated the true stress-strain curves of the hydrides on Grade 1 and 7 titanium using the dual Vickers indentation method, and the critical strain causing the Mode-I fine crack by indentation. Fracture strength and strain of the hydrides in Grade 1 titanium were estimated as 566 MPa and 4.5%, respectively. Those of the hydride in Grade 7 titanium were 498 MPa and 16%. Though the fracture strains estimated from the plastic instability of true stress-strain curves were approximately the half of those estimated by finite element method, the titanium hydrides were estimated to possess some extent of toughness or plastic deformation capability. (author)

Non-Precious Bimetallic Catalysts for Selective Dehydrogenation of an Organic Chemical Hydride System

KAUST Repository

Shaikh Ali, Anaam

2015-07-06

Methylcyclohexane (MCH)-Toluene (TOL) chemical hydride cycles as a hydrogen carrier system is successful with the selective dehydrogenation reaction of MCH to TOL, which has been achieved only using precious Pt-based catalysts. Herein, we report improved selectivity using non-precious metal nickel-based bimetallic catalysts, where the second metal occupies the unselective step sites.

Metal hydride heat pump engineering demonstration and evaluation model

Science.gov (United States)

Lynch, Franklin E.

1993-01-01

Future generations of portable life support systems (PLSS's) for space suites (extravehicular mobility units or EMU's) may require regenerable nonventing thermal sinks (RNTS's). For purposes of mobility, a PLSS must be as light and compact as possible. Previous venting PLSS's have employed water sublimators to reject metabolic and equipment heat from EMU's. It is desirable for long-duration future space missions to minimize the use of water and other consumables that need to be periodically resupplied. The emission of water vapor also interferes with some types of instrumentation that might be used in future space exploration. The test article is a type of RNTS based on a metal hydride heat pump (MHHP). The task of reservicing EMU's after use must be made less demanding in terms of time, procedures, and equipment. The capability for quick turnaround post-EVA servicing (30 minutes) is a challenging requirement for many of the RNTS options. The MHHP is a very simple option that can be regenerated in the airlock within the 30 minute limit by the application of a heating source and a cooling sink. In addition, advanced PLSS's must provide a greater degree of automatic control, relieving astronauts of the need to manually adjust temperatures in their liquid cooled ventilation garments (LCVG's). The MHHP includes automatic coolant controls with the ability to follow thermal load swings from minimum to maximum in seconds. The MHHP includes a coolant loop subsystem with pump and controls, regeneration equipment for post-EVA servicing, and a PC-based data acquisition and control system (DACS).

Fundamental experiments on hydride reorientation in zircaloy

Science.gov (United States)

Colas, Kimberly B.

In the current study, an in-situ X-ray diffraction technique using synchrotron radiation was used to follow directly the kinetics of hydride dissolution and precipitation during thermomechanical cycles. This technique was combined with conventional microscopy (optical, SEM and TEM) to gain an overall understanding of the process of hydride reorientation. Thus this part of the study emphasized the time-dependent nature of the process, studying large volume of hydrides in the material. In addition, a micro-diffraction technique was also used to study the spatial distribution of hydrides near stress concentrations. This part of the study emphasized the spatial variation of hydride characteristics such as strain and morphology. Hydrided samples in the shape of tensile dog-bones were used in the time-dependent part of the study. Compact tension specimens were used during the spatial dependence part of the study. The hydride elastic strains from peak shift and size and strain broadening were studied as a function of time for precipitating hydrides. The hydrides precipitate in a very compressed state of stress, as measured by the shift in lattice spacing. As precipitation proceeds the average shift decreases, indicating average stress is reduced, likely due to plastic deformation and morphology changes. When nucleation ends the hydrides follow the zirconium matrix thermal contraction. When stress is applied below the threshold stress for reorientation, hydrides first nucleate in a very compressed state similar to that of unstressed hydrides. After reducing the average strain similarly to unstressed hydrides, the average hydride strain reaches a constant value during cool-down to room temperature. This could be due to a greater ease of deforming the matrix due to the applied far-field strain which would compensate for the strains due to thermal contraction. Finally when hydrides reorient, the average hydride strains become tensile during the first precipitation regime and

Search for ideal metal hydrides for PEMFC applications

International Nuclear Information System (INIS)

Perng, T.-P.; Shen, C.-C.

2004-01-01

'Full text:' Previously, an LmNi5-based alloy was prepared and its hydrogenation properties were studied. In order to make use of such a type of metal hydride for application in PEMFC, the room-temperature desorption pressure has to be adjusted to 1-2atm and the cyclic stability has to be maintained. In this study, the same alloy was partially substituted with Al and cyclic hydrogenation was conducted with different hydrogen loadings up to 3000 cycles at room temperature. The saturated hydrogen loadings in equilibrium were controlled at H/M = 0.75 and 1.0. The P-C-T curves after 1000, 2000, and 3000 cycles of test were collected at T=30, 50, and 70 o C. After 3000 cycles, it is observed that the maximum hydrogenation capacities of the samples for the loadings of 0.75 and 1.0 are reduced to 0.93 and 0.91, respectively. The plateaus do not change much for T=30 and 50 o C, but become little sloped without observable split at 70 o C. X-ray diffraction analysis shows that the strains associated with repeated hydrogenation are isotropic for all samples. Both unsubstituted and Al-substituted alloys were then used to store hydrogen in a small cylinder with a diameter 10mm and length of 40 mm. The cylinder was connected to a small PEMFC for discharge test at room temperature. More than 540ml H2 was released at below 2atm and discharged to a capacity of 1200mAh. The hydrogenation properties of the alloys and design of the hydrogen storage cylinder for application in small portable PEMFCs for electronic devices are evaluated. The effect of Al substitution and hydrogen loading on cyclic hydrogenation property of the LmNi5-based alloy is also discussed. (author)

A Study on the Radial Hydride Assisted Delayed Hydride Cracking of Zircaloy

Energy Technology Data Exchange (ETDEWEB)

Jeong, Jin-Ho; Lee, Ji-Min; Kim, Yong-Soo [Hanyang University, Seoul (Korea, Republic of)

2015-05-15

Extensive studies have been done on understanding of DHC(Delayed hydride cracking) phenomenon since several zirconium alloy pressure tubes failed in nuclear reactor in the 1970s. Recently, long-term dry storage strategy has been considered seriously in order to manage spent nuclear fuel in Korea and other countries around the world. Consequentially, many researches have been investigated the degradation mechanisms which will threaten the spent fuel integrity during dry storage and showed that hydrogen related phenomenon such as hydride reorientation and DHC are the critical factors. Especially, DHC is the direct cracking mechanism which can cause not only a through-wall defect but also a radiation leak to the environment. In addition, DHC can be enhanced by radial hydride as reported by Kim who demonstrate that radial hydrides clearly act as crack linkage path. This phenomenon is known as the radial hydride assisted DHC (RHA-DHC). Therefore, study on DHC is essential to ensure the safety of spent fuel. Finite element analysis will be carried out for the stress gradient evaluation around notch tip. A variation in thermal cycle which leads to change in hydrogen solid solution trajectory may be required. If the radial hydride precipitates at notch tip, we will investigate what conditions should be met. Ultimately, we will suggest the regulation criteria for long-term dry storage of spent nuclear fuel.

Centrifugal Compressor Surge Controlled

Science.gov (United States)

Skoch, Gary J.

2003-01-01

It shows the variation in compressor mass flow with time as the mass flow is throttled to drive the compressor into surge. Surge begins where wide variations in mass flow occur. Air injection is then turned on to bring about a recovery from the initial surge condition and stabilize the compressor. The throttle is closed further until surge is again initiated. Air injection is increased to again recover from the surge condition and stabilize the compressor.

gamma-Zr-Hydride Precipitate in Irradiated Massive delta- Zr-Hydride

DEFF Research Database (Denmark)

Warren, M. R.; Bhattacharya, D. K.

1975-01-01

During examination of A Zircaloy-2-clad fuel pin, which had been part of a test fuel assembly in a boiling water reactor, several regions of severe internal hydriding were noticed in the upper-plenum end of the pin. Examination of similar fuel pins has shown that hydride of this type is caused by...... to irradiation-induced swelling....

An Investigation on the Persistence of Uranium Hydride during Storage of Simulant Nuclear Waste Packages

OpenAIRE

Stitt , C. A.; Harker , N. J.; Hallam , K. R.; Paraskevoulakos , C.; Banos , A.; Rennie , S.; Jowsey , J.; Scott , T. B.

2015-01-01

International audience; Synchrotron X-rays have been used to study the oxidation of uranium and uranium hydride when encapsulated in grout and stored in de-ionised water for 10 months. Periodic synchrotron X-ray tomography and X-ray powder diffraction have allowed measurement and identification of the arising corrosion products and the rates of corrosion. The oxidation rates of the uranium metal and uranium hydride were slower than empirically derived rates previously reported for each reacta...

Effects of δ-hydride precipitation at a crack tip on crack propagation in delayed hydride cracking of Zircaloy-2

Energy Technology Data Exchange (ETDEWEB)

Kubo, T., E-mail: kubo@nfd.co.jp [Nippon Nuclear Fuel Development Co., Ltd., 2163 Narita-cho, Oarai-machi, Ibaraki 311-1313 (Japan); Kobayashi, Y. [M.O.X. Co., Ltd., 1828-520 Hirasu-cho, Mito, Ibaraki 311-0853 (Japan)

2013-08-15

Highlights: • Steady state crack velocity of delayed hydride cracking in Zircaloy-2 was analyzed. • A large stress peak is induced at an end of hydride by volume expansion of hydride. • Hydrogen diffuses to the stress peak, thereby accelerating steady hydride growth. • Crack velocity was estimated from the calculated hydrogen flux into the stress peak. • There was good agreement between calculation results and experimental data. -- Abstract: Delayed hydride cracking (DHC) of Zircaloy-2 is one possible mechanism for the failure of boiling water reactor fuel rods in ramp tests at high burnup. Analyses were made for hydrogen diffusion around a crack tip to estimate the crack velocity of DHC in zirconium alloys, placing importance on effects of precipitation of δ-hydride. The stress distribution around the crack tip is significantly altered by precipitation of hydride, which was strictly analyzed using a finite element computer code. Then, stress-driven hydrogen diffusion under the altered stress distribution was analyzed by a differential method. Overlapping of external stress and hydride precipitation at a crack tip induces two stress peaks; one at a crack tip and the other at the front end of the hydride precipitate. Since the latter is larger than the former, more hydrogen diffuses to the front end of the hydride precipitate, thereby accelerating hydride growth compared with that in the absence of the hydride. These results indicated that, after hydride was formed in front of the crack tip, it grew almost steadily accompanying the interaction of hydrogen diffusion, hydride growth and the stress alteration by hydride precipitation. Finally, crack velocity was estimated from the calculated hydrogen flux into the crack tip as a function of temperature, stress intensity factor and material strength. There was qualitatively good agreement between calculation results and experimental data.

Gas atomization of Cu-modified AB5 metal hydride alloys

International Nuclear Information System (INIS)

Young, K.; Ouchi, T.; Banik, A.; Koch, J.; Fetcenko, M.A.; Bendersky, L.A.; Wang, K.; Vaudin, M.

2011-01-01

Research highlights: → The gas atomization process together with a hydrogen annealing process was demonstrated on AB5 alloys. → The method was found to be effective in restoring the original cycle life sacrificed by the incorporation of copper in the alloy formula as a means of improving the low temperature performance of AB 5 alloys. → The new process also improves high rate, low temperature, and charge retention performances for both Cu-free and Cu-containing AB 5 alloys. - Abstract: Gas atomization together with a hydrogen annealing process has been proposed as a method to achieve improved low-temperature performance of AB 5 alloy electrodes in Ni/MH batteries and restore the original cycle life which was sacrificed by the incorporation of copper in the alloy formula. While the gas atomization process reduces the lattice constant aspect ratio c/a of the Cu-containing alloys, the addition of a hydrogen annealing step recovers this property, although it is still inferior to the conventionally prepared annealed Cu-free alloy. This observation correlates very well with the cycle life performance. In addition to extending the cycle life of the Cu-containing metal hydride electrode, processing by gas atomization with additional hydrogen annealing improves high-rate, low-temperature, and charge retention performances for both Cu-free and Cu-containing AB 5 alloys. The degradation mechanisms of alloys made by different processes through cycling are also discussed.

Hydride effect on crack instability of Zircaloy cladding

Energy Technology Data Exchange (ETDEWEB)

Tseng, Che-Chung, E-mail: cctseng@iner.gov.tw [Institute of Nuclear Energy Research, No. 1000, Wunhua Road, Jiaan Village, Lungtan, Township, Taoyuan County 32546, Taiwan (China); Sun, Ming-Hung [Institute of Nuclear Energy Research, No. 1000, Wunhua Road, Jiaan Village, Lungtan, Township, Taoyuan County 32546, Taiwan (China); Chao, Ching-Kong [Department of Mechanical Engineering, National Taiwan University of Science and Technology, 43 Keelung Road, Section 4, Taipei 106, Taiwan (China)

2014-04-01

Highlights: • Radial hydrides near the crack tip had a significant effect on crack propagation. • For radial hydrides off the crack line vertically, the effect on crack propagation was notably reduced. • The longer hydride platelet resulted in a remarkable effect on crack propagation. • A long split in the radial hydride precipitate would enhance crack propagation. • The presence of circumferential hydride among radial hydrides may play an important role in crack propagation. - Abstract: A methodology was proposed to investigate the effect of hydride on the crack propagation in fuel cladding. The analysis was modeled based on an outside-in crack with radial hydrides located near its crack tip. The finite element method was used in the calculation; both stress intensity factor K{sub I} and J integral were applied to evaluate the crack stability. The parameters employed in the analysis included the location of radial hydride, hydride dimensions, number of hydrides, and the presence of circumferential hydride, etc. According to our study, the effective distance between a radial hydride and the assumed cladding surface crack for the enhancement of crack propagation proved to be no greater than 0.06 mm. For a hydride not on the crack line, it would induce a relatively minor effect on crack propagation if the vertical distance was beyond 0.05 mm. However, a longer hydride precipitate as well as double radial hydrides could have a remarkable effect on crack propagation. A combined effect of radial and circumferential hydrides was also discussed.

Classical and Statistical Thermodynamics of Unstable Intermetallic Hydrides at Hydrogen Pressures Up to 1,000 Atmospheres

International Nuclear Information System (INIS)

Beeri, O.

2000-11-01

Thermodynamic and structural studies of numerous intermetallic hydride systems have been performed during the last three decades. Those systems have the potential use for a versatile range of applications such as pure hydrogen storage, heat pumps devices, energy storage, hydrogenation catalysts, thermal compressors, hydrogen purification systems, rechargeable batteries and more. Also, those hydrides have some very interesting fundamental properties related to diffusion studies, gas-solid reactions, isotopic effects, etc. Those applications and fundamentals strongly motivated an extensive research in this field. Most of those studies were limited to the low ( ∼2-x Mn x (0 0, usually the C14 allotrope exists. This property allows for the separation of the compounds properties with respect to their chemical compositions or with respect to their crystallographic structures. The present work includes preparation of the compounds, and their metallurgic, chemical and crystallographic characterization. The reaction of the compounds with hydrogen was studied in a very high-pressure system, which allows pressure-composition (p-c) isotherms measurements of pressures up to 1,000 atm and over a wide range of temperatures. In addition, the reaction of palladium with hydrogen was characterized as well. The palladium-hydrogen system, which is probably the most studied metal-hydrogen system, was chosen to confirm the validity of the experiments and the model calculations. For all samples the isotherms were measured using protium (H 2 ), while in some cases some deuterium (D 2 ) isotherms were measured as well. In this high-pressure range (and actual temperatures) the non-ideality of the gas phase was considered in the isotherm calculations as well as in the thermodynamic calculations. Having the p-c isotherms, the reaction enthalpy change, ΔH, and entropy change, ΔS, were calculated for all systems. Those values of ΔH and ΔS, were found to be in very good agreement with the

The Compressor Recycle System

OpenAIRE

Barstad, Bjørn Ove

2010-01-01

The compressor recycle system is the main focus of this thesis. When the mass flow through a compressor becomes too low, the compressor can plunge into surge. Surge is a term that is used for axisymmetric oscillation through a compressor and is highly unwanted. The recycle system feeds compressed gas back to the intake when the mass flow becomes too low, and thereby act as a safety system.A mathematical model of the recycle system is extended and simulated in SIMULINK. The mathematical model ...

Complex metal hydrides

DEFF Research Database (Denmark)

Ley, Morten Brix

2014-01-01

og batterier de to mest lovende energibærere til mobile applikationer. Komplekse metalhydrider er blevet undersøgt i vid udstrækning over de sidste tyve år, siden de gravimetrisk og volumetrisk kan indeholde store mængder brint. Derfor er metal borhydrider velegnet til faststofopbevaring af brint...

Experimental investigation of strain, damage and failure of hydrided zircaloy-4 with various hydride orientations

International Nuclear Information System (INIS)

Racine, A; Catherine, C.S.; Cappelaere, C.; Bornert, M.; Caldemaison, D.

2005-01-01

This experimental investigation is devoted to the influence of the orientation of hydrides on the mechanical response of Zircaloy-4. Ring tensile tests are performed on unirradiated CWSR Zircaloy-4, charged with about 200 or 500wppm hydrogen. Hydrides are oriented either parallel ('tangential'), or perpendicular ('radial') to the circumferential tensile direction. Tangential hydrides are usually observed in cladding tubes, however, hydrides can be reoriented after cooling under stress to become radial and then trigger brittle behavior. In this investigation, we perform, 'macroscopic' or SEM in-situ tensile tests on smooth rings, at room temperature. We get the mechanical response of the material as a function of hydride orientation and hydrogen content and we investigate the deformation, damage and failure mechanisms. In both cases, digital image correlation techniques are used to estimate local and global strain distributions. The results lead to the following conclusions: neither the tensile stress-strain response nor the strain modes are affected by hydrogen content or hydride orientation, but the failure modes are. Indeed, only 200wppm radial hydrides embrittle Zy-4: sample fails in the elastic domain at about 350 MPa before strain bands could develop; whereas in other cases samples reach at least 750 MPa before failure, with ductile or brittle mode. (authors)

High Sensitive Methods for Health Monitoring of Compressor Blades and Fatigue Detection

Science.gov (United States)

Witoś, Mirosław

2013-01-01

The diagnostic and research aspects of compressor blade fatigue detection have been elaborated in the paper. The real maintenance and overhaul problems and characteristic of different modes of metal blade fatigue (LCF, HCF, and VHCF) have been presented. The polycrystalline defects and impurities influencing the fatigue, along with their related surface finish techniques, are taken into account. The three experimental methods of structural health assessment are considered. The metal magnetic memory (MMM), experimental modal analysis (EMA) and tip timing (TTM) methods provide information on the damage of diagnosed objects, for example, compressor blades. Early damage symptoms, that is, magnetic and modal properties of material strengthening and weakening phases (change of local dislocation density and grain diameter, increase of structural and magnetic anisotropy), have been described. It has been proven that the shape of resonance characteristic gives abilities to determine if fatigue or a blade crack is concerned. The capabilities of the methods for steel and titanium alloy blades have been illustrated in examples from active and passive experiments. In the conclusion, the MMM, EMA, and TTM have been verified, and the potential for reliable diagnosis of the compressor blades using this method has been confirmed. PMID:24191135

High Sensitive Methods for Health Monitoring of Compressor Blades and Fatigue Detection

Directory of Open Access Journals (Sweden)

Mirosław Witoś

2013-01-01

Full Text Available The diagnostic and research aspects of compressor blade fatigue detection have been elaborated in the paper. The real maintenance and overhaul problems and characteristic of different modes of metal blade fatigue (LCF, HCF, and VHCF have been presented. The polycrystalline defects and impurities influencing the fatigue, along with their related surface finish techniques, are taken into account. The three experimental methods of structural health assessment are considered. The metal magnetic memory (MMM, experimental modal analysis (EMA and tip timing (TTM methods provide information on the damage of diagnosed objects, for example, compressor blades. Early damage symptoms, that is, magnetic and modal properties of material strengthening and weakening phases (change of local dislocation density and grain diameter, increase of structural and magnetic anisotropy, have been described. It has been proven that the shape of resonance characteristic gives abilities to determine if fatigue or a blade crack is concerned. The capabilities of the methods for steel and titanium alloy blades have been illustrated in examples from active and passive experiments. In the conclusion, the MMM, EMA, and TTM have been verified, and the potential for reliable diagnosis of the compressor blades using this method has been confirmed.

Hydrogen storage alloy electrode for metal-hydride alkaline storage battery its production method; Kinzoku-suisokabutsu aruakri chikudenchiyo no suiso kyuzo gokin denkyoku oyobi sono seizo hoho

Energy Technology Data Exchange (ETDEWEB)

Matsuura, Y.; Nogami, K.; Kimoto, M.; Higashiyama, N.; Kuroda, Y.; Yonezu, I.; Nishio, K.

1997-03-28

Recently, it is proposed to employ the hydrogen storage alloy produced by means of rapidly solidifying single roll method, i.e., a method of projecting the molten alloy onto the surface of roll rotating in high speed as for the negative electrode material of the metal hydride alkaline battery. However, the hydrogen storage alloy produced by the single roll method has a heterogeneous grain size. So that the utilization of the hydrogen storage alloy is limited. This invention solves the problem. The rare earth-nickel system hydrogen storage alloy ribbon with average thickness of 0.08 - 0.35 mm is produced by means of single roll method. The grain size of the alloy is over 0.2 micrometer on roll surface side and below 20 micrometers on open surface side. The above said alloy is ground to average particle size of 25 - 70 micrometers to be used for the hydrogen absorbent. In this way, the metal hydride alkaline battery with excellent high rate discharge characteristic at the initial stage of charge-discharge cycle, excellent charge-discharge cycle characteristic, and excellent inner pressure characteristic can be produced. 2 figs., 5 tabs.

Hydriding failure in water reactor fuel elements

International Nuclear Information System (INIS)

Sah, D.N.; Ramadasan, E.; Unnikrishnan, K.

1980-01-01

Hydriding of the zircaloy cladding has been one of the important causes of failure in water reactor fuel elements. This report reviews the causes, the mechanisms and the methods for prevention of hydriding failure in zircaloy clad water reactor fuel elements. The different types of hydriding of zircaloy cladding have been classified. Various factors influencing zircaloy hydriding from internal and external sources in an operating fuel element have been brought out. The findings of post-irradiation examination of fuel elements from Indian reactors, with respect to clad hydriding and features of hydriding failure are included. (author)

Hydrogen-deuterium exchange of the anionic group 6B transition-metal hydrides. Convenient, in-situ-deuterium transfer reagents

International Nuclear Information System (INIS)

Gaus, P.L.; Kao, S.C.; Darensbourg, M.Y.; Arndt, L.W.

1984-01-01

The facile exchange of hydrogen for detuerium in the anionic group 6B carbonyl hydrides HM(CO) 4 L - (M = Cr, W; L = CO P(OMe) 3 ) has been studied in THF 4 (tetrahydrofuran) with CH 3 OD, D 2 O, and CH 3 CO 2 D. This has provided a synthesis of the deuterides, DM(CO) 4 L - , as well as a convenient in situ source of deuteride reducing reagents for organic halides. A number of such reductions are described, using 2 H NMR to demonstrate both selectivity and stereospecificity for certain systems. The carbonyl region of the infrared spectra of the hydrides is not affected by deuteration of the hydrides, suggesting that the M-H or M-D vibrational modes are not coupled significantly to CO vibrations in these hydrides. The mechanism of the H/D exchange and of a related H 2 elimination reaction is discussed

Titanium tritide radioisotope heat source development: palladium-coated titanium hydriding kinetics and tritium loading tests

International Nuclear Information System (INIS)

Van Blarigan, Peter; Shugard, Andrew D.; Walters, R. Tom

2012-01-01

We have found that a 180 nm palladium coating enables titanium to be loaded with hydrogen isotopes without the typical 400-500 C vacuum activation step. The hydriding kinetics of Pd coated Ti can be described by the Mintz-Bloch adherent film model, where the rate of hydrogen absorption is controlled by diffusion through an adherent metal-hydride layer. Hydriding rate constants of Pd coated and vacuum activated Ti were found to be very similar. In addition, deuterium/tritium loading experiments were done on stacks of Pd coated Ti foil in a representative-size radioisotope heat source vessel. The experiments demonstrated that such a vessel could be loaded completely, at temperatures below 300 C, in less than 10 hours, using existing department-of-energy tritium handling infrastructure.

An Investigation on the Persistence of Uranium Hydride during Storage of Simulant Nuclear Waste Packages.

Science.gov (United States)

Stitt, C A; Harker, N J; Hallam, K R; Paraskevoulakos, C; Banos, A; Rennie, S; Jowsey, J; Scott, T B

2015-01-01

Synchrotron X-rays have been used to study the oxidation of uranium and uranium hydride when encapsulated in grout and stored in de-ionised water for 10 months. Periodic synchrotron X-ray tomography and X-ray powder diffraction have allowed measurement and identification of the arising corrosion products and the rates of corrosion. The oxidation rates of the uranium metal and uranium hydride were slower than empirically derived rates previously reported for each reactant in an anoxic water system, but without encapsulation in grout. This was attributed to the grout acting as a physical barrier limiting the access of oxidising species to the uranium surface. Uranium hydride was observed to persist throughout the 10 month storage period and industrial consequences of this observed persistence are discussed.

New technique for producing the alloys based on transition metals

International Nuclear Information System (INIS)

Dolukhanyan, S.K.; Aleksanyan, A.G.; Shekhtman, V.Sh.; Mantashyan, A.A.; Mayilyan, D.G.; Ter-Galstyan, O.P.

2007-01-01

In principle new technique was elaborated for obtaining the alloys of refractory metals by their hydrides compacting and following dehydrogenation. The elaborated technique is described. The conditions of alloys formation from different hydrides of appropriate metals was investigated in detail. The influence of the process parameters such as: chemical peculiarities, composition of source hydrides, phase transformation during dehydrogenation, etc. on the alloys formation were established. The binary and tertiary alloys of α and ω phases: Ti 0 .8Zr 0 .8; Ti 0 .66Zr 0 .33; Ti 0 .3Zr 0 .8; Ti 0 .2Zr 0 .8; Ti 0 .8Hf 0 .2; Ti 0 .6Hf 0 .4Ti 0 .66Zr 0 .23Hf 0 .11; etc were recieved. Using elaborated special hydride cycle, an earlier unknown effective process for formation of alloys of transition metals was realized. The dependence of final alloy structure on the composition of initial mixture and hydrogen content in source hydrides was established

Preparation of beryllium hydride

International Nuclear Information System (INIS)

Roberts, C.B.

1975-01-01

A process is described for preparing beryllium hydride by the direct reaction of beryllium borohydride and aluminum hydride trimethylamine adduct. Volatile by-products and unreacted reactants are readily removed from the product mass by sublimation and/or evaporation. (U.S.)

Nanostructured, complex hydride systems for hydrogen generation

Directory of Open Access Journals (Sweden)

Robert A. Varin

2015-02-01

Full Text Available Complex hydride systems for hydrogen (H2 generation for supplying fuel cells are being reviewed. In the first group, the hydride systems that are capable of generating H2 through a mechanical dehydrogenation phenomenon at the ambient temperature are discussed. There are few quite diverse systems in this group such as lithium alanate (LiAlH4 with the following additives: nanoiron (n-Fe, lithium amide (LiNH2 (a hydride/hydride system and manganese chloride MnCl2 (a hydride/halide system. Another hydride/hydride system consists of lithium amide (LiNH2 and magnesium hydride (MgH2, and finally, there is a LiBH4-FeCl2 (hydride/halide system. These hydride systems are capable of releasing from ~4 to 7 wt.% H2 at the ambient temperature during a reasonably short duration of ball milling. The second group encompasses systems that generate H2 at slightly elevated temperature (up to 100 °C. In this group lithium alanate (LiAlH4 ball milled with the nano-Fe and nano-TiN/TiC/ZrC additives is a prominent system that can relatively quickly generate up to 7 wt.% H2 at 100 °C. The other hydride is manganese borohydride (Mn(BH42 obtained by mechano-chemical activation synthesis (MCAS. In a ball milled (2LiBH4 + MnCl2 nanocomposite, Mn(BH42 co-existing with LiCl can desorb ~4.5 wt.% H2 at 100 °C within a reasonable duration of dehydrogenation. Practical application aspects of hydride systems for H2 generation/storage are also briefly discussed.

Influence of Climatic Factors on the Efficiency of Disposal Metal- Hydride Unit for the Double-Fuel Low-Speed Internal Combustion Engine of Gas Tankers

OpenAIRE

Cherednichenko, Oleksandr Costyntunovich; Tkach, Mykhaylo Romanovich

2017-01-01

Contemporary tendencies in the development of ship power engineering have been analyzed. Consideration was given to the specific features of the transportation of liquefied natural gas by gas tankers. The prospects of utilization of the secondary energy resources of marine double-fuel low-speed diesel engines were defined. The metal hydride units of a continuous action were offered for this purpose. The need for the estimation of the influence of climatic factors on the efficiency of disposal...

Effects of Boron-Incorporation in a V-Containing Zr-Based AB2 Metal Hydride Alloy

Directory of Open Access Journals (Sweden)

Shiuan Chang

2017-11-01

Full Text Available In this study, boron, a metalloid element commonly used in semiconductor applications, was added in a V-containing Zr-based AB2 metal hydride alloy. In general, as the boron content in the alloy increased, the high-rate dischargeability, surface exchange current, and double-layer capacitance first decreased and then increased whereas charge-transfer resistance and dot product of charge-transfer resistance and double-layer capacitance changed in the opposite direction. Electrochemical and gaseous phase characteristics of two boron-containing alloys, with the same boron content detected by the inductively coupled plasma optical emission spectrometer, showed significant variations in performances due to the difference in phase abundance of a newly formed tetragonal V3B2 phase. This new phase contributes to the increases in electrochemical high-rate dischargeability, surface exchange current, charge-transfer resistances at room, and low temperatures. However, the V3B2 phase does not contribute to the hydrogen storage capacities in either gaseous phase and electrochemical environment.

Electron Backscatter Diffraction Studies on the Formation of Superlattice Metal Hydride Alloys

Directory of Open Access Journals (Sweden)

Shuli Yan

2017-12-01

Full Text Available Microstructures of a series of La-Mg-Ni-based superlattice metal hydride alloys produced by a novel method of interaction of a LaNi5 alloy and Mg vapor were studied using a combination of X-ray energy dispersive spectroscopy and electron backscatter diffraction. The conversion rate of LaNi5 increased from 86.8% into 98.2%, and the A2B7 phase abundance increased from 42.5 to 45.8 wt % and reduced to 39.2 wt % with the increase in process time from four to 32 h. During the first stage of reaction, Mg formed discrete grains with the same orientation, which was closely related to the orientation of the host LaNi5 alloy. Mg then diffused through the ab-phase of LaNi5 and formed the AB2, AB3, and A2B7 phases. Diffusion of Mg stalled at the grain boundary of the host LaNi5 alloy. Good alignments in the c-axis between the newly formed superlattice phases and LaNi5 were observed. The density of high-angle grain boundary decreased with the increase in process time and was an indication of lattice cracking.

Hydrogen storage alloy electrode of metal hydride alkaline storage battery and its production method; Kinzoku-suisokabutsu arukari chikudenchiyo no suiso kyuzo gokin denkyoku oyobi sono seizo hoho

Energy Technology Data Exchange (ETDEWEB)

Matsuura, Y.; Nogami, K.; Kimoto, M.; Higashiyama, N.; Kuroda, Y.; Yonezu, I.; Nishio, K.

1997-03-28

Recently, a proposal was made of employing the hydrogen storage alloy produced by means f rapidly solidifying single roll method, i.e., a method of projecting the molten alloy onto the surface of roll rotating in high speed as for the negative electrode material of the metal hydride alkaline battery. However, the hydrogen storage alloy produced by the single roll method has a heterogeneous grain size. This invention solves the problem. The Mm{center_dot}Ni{center_dot}Co{center_dot}Al{center_dot}Mn alloy ribbon with average thickness of 0.08 - 0.35 mm is produced by means of single roll method. The grain size of the alloy is over 0.2 micrometer on roll surface side and below 18 micrometers on open surface side. The alloy is ground to be used for the hydrogen absorbent. The general formula of this alloy is MmR(x) (Mm = mischmetal, R = Ni, Co, Al, Mn). In this way, the metal hydride alkaline battery with excellent high rate discharge characteristic at the initial stage of charge-discharge cycle, excellent charge-discharge cycle characteristic, and excellent inner pressure characteristic can be produced. 2 figs., 5 tabs.

Studies of hydrogen absorption and desorption processes in advanced intermetallic hydrides

Energy Technology Data Exchange (ETDEWEB)

Sato, Masashi

2005-07-01

This work is a part of the research program performed in the Department of Energy Systems, Institute for Energy Technology (Kjeller, Norway), which is focused on the development of the advanced hydrogen storage materials. The activities are aimed on studies of the mechanisms of hydrogen interactions with intermetallic alloys with focus on establishing an interrelation between the crystal structure, thermodynamics and kinetics of the processes in the metal-hydrogen systems, on the one hand, and hydrogen storage properties (capacity, rates of desorption, hysteresis). Many of the materials under investigation have potential to be applied in applications, whereas some already have been commercialised in the world market. A number of metals take up considerable amounts of hydrogen and form chemical compounds with H, metal hydrides. Unfortunately, binary hydrides are either very stable (e.g. for the rare earth metals [RE], Zr, Ti, Mg: metal R) or are formed at very high applied pressures of hydrogen gas (e.g. for the transition metals, Ni, Co, Fe, etc.: Metal T). However, hydrogenation process becomes easily reversible at very convenient from practical point of view conditions, around room temperature and at H2 pressures below 1 MPa for the two-component intermetallic alloys R{sub x}T{sub y}. This raised and maintains further interest to the intermetallic hydrides as solid H storage materials. Materials science research of this thesis is focused on studies of the reasons staying behind the beneficial effect of two non-transition elements M(i.e., In and Sn) contributing to the formation of the ternary intermetallic alloys R{sub x}T{sub y}M{sub 2}., on the hydrogen storage behaviours. Particular focus is on two aspects where the remarkable improvement of ordinary metal hydrides is achieved via introduction of In and Sn: a) Increase of the volume density of stored hydrogen in solid materials to the record high level. b) Improvement of the kinetics of hydrogen charge and

Cooled spool piston compressor

Science.gov (United States)

Morris, Brian G. (Inventor)

1993-01-01

A hydraulically powered gas compressor receives low pressure gas and outputs a high pressure gas. The housing of the compressor defines a cylinder with a center chamber having a cross-sectional area less than the cross-sectional area of a left end chamber and a right end chamber, and a spool-type piston assembly is movable within the cylinder and includes a left end closure, a right end closure, and a center body that are in sealing engagement with the respective cylinder walls as the piston reciprocates. First and second annual compression chambers are provided between the piston enclosures and center housing portion of the compressor, thereby minimizing the spacing between the core gas and a cooled surface of the compressor. Restricted flow passageways are provided in the piston closure members and a path is provided in the central body of the piston assembly, such that hydraulic fluid flows through the piston assembly to cool the piston assembly during its operation. The compressor of the present invention may be easily adapted for a particular application, and is capable of generating high gas pressures while maintaining both the compressed gas and the compressor components within acceptable temperature limits.

Discovery of Novel Complex Metal Hydrides for Hydrogen Storage through Molecular Modeling and Combinatorial Methods

Energy Technology Data Exchange (ETDEWEB)

Lesch, David A; Adriaan Sachtler, J.W. J.; Low, John J; Jensen, Craig M; Ozolins, Vidvuds; Siegel, Don; Harmon, Laurel

2011-02-14

UOP LLC, a Honeywell Company, Ford Motor Company, and Striatus, Inc., collaborated with Professor Craig Jensen of the University of Hawaii and Professor Vidvuds Ozolins of University of California, Los Angeles on a multi-year cost-shared program to discover novel complex metal hydrides for hydrogen storage. This innovative program combined sophisticated molecular modeling with high throughput combinatorial experiments to maximize the probability of identifying commercially relevant, economical hydrogen storage materials with broad application. A set of tools was developed to pursue the medium throughput (MT) and high throughput (HT) combinatorial exploratory investigation of novel complex metal hydrides for hydrogen storage. The assay programs consisted of monitoring hydrogen evolution as a function of temperature. This project also incorporated theoretical methods to help select candidate materials families for testing. The Virtual High Throughput Screening served as a virtual laboratory, calculating structures and their properties. First Principles calculations were applied to various systems to examine hydrogen storage reaction pathways and the associated thermodynamics. The experimental program began with the validation of the MT assay tool with NaAlH4/0.02 mole Ti, the state of the art hydrogen storage system given by decomposition of sodium alanate to sodium hydride, aluminum metal, and hydrogen. Once certified, a combinatorial 21-point study of the NaAlH4 LiAlH4Mg(AlH4)2 phase diagram was investigated with the MT assay. Stability proved to be a problem as many of the materials decomposed during synthesis, altering the expected assay results. This resulted in repeating the entire experiment with a mild milling approach, which only temporarily increased capacity. NaAlH4 was the best performer in both studies and no new mixed alanates were observed, a result consistent with the VHTS. Powder XRD suggested that the reverse reaction, the regeneration of the

A new battery capacity indicator for nickel-metal hydride battery powered electric vehicles using adaptive neuro-fuzzy inference system

International Nuclear Information System (INIS)

Chau, K.T.; Wu, K.C.; Chan, C.C.; Shen, W.X.

2003-01-01

This paper describes a new approach to estimate accurately the battery residual capacity (BRC) of the nickel-metal hydride (Ni-MH) battery for modern electric vehicles (EVs). The key to this approach is to model the Ni-MH battery in EVs by using the adaptive neuro-fuzzy inference system (ANFIS) with newly defined inputs and output. The inputs are the temperature and the discharged capacity distribution describing the discharge current profile, while the output is the state of available capacity (SOAC) representing the BRC. The estimated SOAC from ANFIS model and the measured SOAC from experiments are compared, and the results confirm that the proposed approach can provide an accurate estimation of the SOAC under variable discharge currents

Alkali Metal Cation Affinities of Anionic Main Group-Element Hydrides Across the Periodic Table.

Science.gov (United States)

Boughlala, Zakaria; Fonseca Guerra, Célia; Bickelhaupt, F Matthias

2017-10-05

We have carried out an extensive exploration of gas-phase alkali metal cation affinities (AMCA) of archetypal anionic bases across the periodic system using relativistic density functional theory at ZORA-BP86/QZ4P//ZORA-BP86/TZ2P. AMCA values of all bases were computed for the lithium, sodium, potassium, rubidium and cesium cations and compared with the corresponding proton affinities (PA). One purpose of this work is to provide an intrinsically consistent set of values of the 298 K AMCAs of all anionic (XH n-1 - ) constituted by main group-element hydrides of groups 14-17 along the periods 2-6. In particular, we wish to establish the trend in affinity for a cation as the latter varies from proton to, and along, the alkali cations. Our main purpose is to understand these trends in terms of the underlying bonding mechanism using Kohn-Sham molecular orbital theory together with a quantitative bond energy decomposition analyses (EDA). © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Development of nickel/metal-hydride batteries for EVs and HEVs

Science.gov (United States)

Taniguchi, Akihiro; Fujioka, Noriyuki; Ikoma, Munehisa; Ohta, Akira

This paper is to introduce the nickel/metal-hydride (Ni/MH) batteries for electric vehicles (EVs) and hybrid electric vehicles (HEVs) developed and mass-produced by our company. EV-95 for EVs enables a vehicle to drive approximately 200 km per charge. As the specific power is extremely high, more than 200 W/kg at 80% depth of discharge (DOD), the acceleration performance is equivalent to that of gasoline fuel automobiles. The life characteristic is also superior. This battery gives the satisfactory result of more than 1000 cycles in bench tests and approximately 4-year on-board driving. EV-28 developed for small EVs comprises of a compact and light battery module with high specific power of 300 W/kg at 80% DOD by introducing a new technology for internal cell connection. Meanwhile, our cylindrical battery for the HEV was adopted into the first generation Toyota Prius in 1997 which is the world's first mass-product HEV, and has a high specific power of 600 W/kg. Its life characteristic was found to be equivalent to more than 100,000 km driving. Furthermore, a new prismatic module in which six cells are connected internally was used for the second generation Prius in 2000. The prismatic battery comprises of a compact and light battery pack with a high specific power of 1000 W/kg, which is approximately 1.7 times that of conventional cylindrical batteries, as a consequence of the development of a new internal cell connection and a new current collection structure.

Decomposition kinetics of plutonium hydride

Energy Technology Data Exchange (ETDEWEB)

Haschke, J.M.; Stakebake, J.L.

1979-01-01

Kinetic data for decomposition of PuH/sub 1/ /sub 95/ provides insight into a possible mechanism for the hydriding and dehydriding reactions of plutonium. The fact that the rate of the hydriding reaction, K/sub H/, is proportional to P/sup 1/2/ and the rate of the dehydriding process, K/sub D/, is inversely proportional to P/sup 1/2/ suggests that the forward and reverse reactions proceed by opposite paths of the same mechanism. The P/sup 1/2/ dependence of hydrogen solubility in metals is characteristic of the dissociative absorption of hydrogen; i.e., the reactive species is atomic hydrogen. It is reasonable to assume that the rates of the forward and reverse reactions are controlled by the surface concentration of atomic hydrogen, (H/sub s/), that K/sub H/ = c'(H/sub s/), and that K/sub D/ = c/(H/sub s/), where c' and c are proportionality constants. For this surface model, the pressure dependence of K/sub D/ is related to (H/sub s/) by the reaction (H/sub s/) reversible 1/2H/sub 2/(g) and by its equilibrium constant K/sub e/ = (H/sub 2/)/sup 1/2//(H/sub s/). In the pressure range of ideal gas behavior, (H/sub s/) = K/sub e//sup -1/(RT)/sup -1/2/ and the decomposition rate is given by K/sub D/ = cK/sub e/(RT)/sup -1/2/P/sup 1/2/. For an analogous treatment of the hydriding process with this model, it can be readily shown that K/sub H/ = c'K/sub e//sup -1/(RT)/sup -1/2/P/sup 1/2/. The inverse pressure dependence and direct temperature dependence of the decomposition rate are correctly predicted by this mechanism which is most consistent with the observed behavior of the Pu--H system.

Cyclopentadiene-mediated hydride transfer from rhodium complexes.

Science.gov (United States)

Pitman, C L; Finster, O N L; Miller, A J M

2016-07-12

Attempts to generate a proposed rhodium hydride catalytic intermediate instead resulted in isolation of (Cp*H)Rh(bpy)Cl (1), a pentamethylcyclopentadiene complex, formed by C-H bond-forming reductive elimination from the fleeting rhodium hydride. The hydride transfer ability of diene 1 was explored through thermochemistry and hydride transfer reactions, including the reduction of NAD(+).

Electrochemical and metallurgical characterization of ZrCr{sub 1-x}NiMo{sub x} AB{sub 2} metal hydride alloys

Energy Technology Data Exchange (ETDEWEB)

Erika, Teliz [Universidad de la República, Facultad de Ciencias, Laboratorio de Electroquímica Fundamental, Núcleo Interdisciplinario Ingeniería Electroquímica, Igua 4225, CP 11400 Montevideo (Uruguay); Ricardo, Faccio [Universidad de la República, Crystallography, Solid State and Materials Laboratory (Cryssmat-Lab), DETEMA, Centro NanoMat, Polo Tecnológico de Pando, Espacio Interdisciplinario, Facultad de Química, Montevideo (Uruguay); Fabricio, Ruiz [Consejo Nacional de Investigaciones Científicas y Técnicas , CONICET, Av. Rivadavia 1917, C1033AAJ Ciudad de Buenos Aires (Argentina); Centro Atómico Bariloche , Comisión Nacional de Energía Atómica (CAB-CNEA), Av. Bustillo 9500, CP 8400 S.C. de Bariloche, RN (Argentina); Fernando, Zinola [Universidad de la República, Facultad de Ciencias, Laboratorio de Electroquímica Fundamental, Núcleo Interdisciplinario Ingeniería Electroquímica, Igua 4225, CP 11400 Montevideo (Uruguay); and others

2015-11-15

The effects of partial replacement of chromium by molybdenum was studied on the structure and electrochemical kinetic properties of ZrCr{sub 1-x}NiMo{sub x}(x = 0.0, 0.3 and 0.6) metal hydride alloys. The arc-melting prepared alloys were metallurgically characterized by X-ray diffraction and energy dispersive spectroscopy microanalysis, which showed AB{sub 2} (with hexagonal C14 structure) and Zr{sub x}Ni{sub y} (Zr{sub 7}Ni{sub 10}, Zr{sub 9}Ni{sub 11}) phases. After a partial substitution of chromium by molybdenum, secondary phases monotonically increase with the C14 unit cell volume indicating that most of molybdenum atoms locate in the B-site. The alloys were electrochemically characterized using charge/discharge cycling, electrochemical impedance spectroscopy and rate capability experiments that allowed the determination of hydriding reaction kinetic parameters. The presence of molybdenum produces a positive effect for hydrogen diffusion in the alloy lattice, and ZrCr{sub 0.7}NiMo{sub 0.3} alloy depicts the better kinetics associated with a fast activation, lower charge transfer resistance and the best high rate discharge behavior. This fact would be related to a lower diffusion time constant and a bigger value of the product between exchange density current and surface active area. There is a trade-off in the amounts of secondary phase and Laves phases in order to improve the kinetic performance. - Highlights: • Metallurgical characterization evidences the presence of Zr{sub x}Ni{sub y} and C14 phases. • The partial replacement of Cr by Mo promotes the segregation of Zr{sub x}Ni{sub y} phase. • The incorporation of molybdenum improves the kinetics for the hydriding process. • Mo produces a decrease in the diffusion time constant.

Processing method of radioactive metal wastes

International Nuclear Information System (INIS)

Uetake, Naoto; Urata, Megumu; Sato, Masao.

1985-01-01

Purpose: To reduce the volume and increase the density of radioactive metal wastes easily while preventing scattering of radioactivity and process them into suitable form to storage and treatment. Method: Metal wastes mainly composed of zirconium are discharged from nuclear power plants or fuel re-processing plants, and these metals such as zirconium and titanium vigorously react with hydrogen and rapidly diffuse as hydrides. Since the hydrides are extremely brittle and can be pulverized easily, they can be volume-reduced. However, since metal hydrides have no ductility, dehydrogenation is applied for the molding fabrication in view of the subsequent storage and processing. The dehydrogenation is easy like the hydrogenation and fine metal pieces can be molded in a small compression device. For the dehydrogenation, a temperature is slightly increased as compared with that in the hydrogenation, pressure is reduced through the vacuum evacuation system and the removed hydrogen is purified for reuse. The upper limit for the temperature of the hydrogenation is 680 0 C in order to prevent the scttering of radioactivity. (Kamimura, M.)

Catalytic effect of halide additives ball milled with magnesium hydride

Energy Technology Data Exchange (ETDEWEB)

Malka, I.E.; Bystrzycki, J. [Department of Advanced Materials and Technologies, Military University of Technology, Kaliskiego 2, 00-908 Warsaw (Poland); Czujko, T. [Department of Advanced Materials and Technologies, Military University of Technology, Kaliskiego 2, 00-908 Warsaw (Poland); CanmetENERGY, Hydrogen Fuel Cells and Transportation Energy, Natural Resources (Canada)

2010-02-15

The influence of various halide additives milled with magnesium hydride (MgH{sub 2}) on its decomposition temperature was studied. The optimum amount of halide additive and milling conditions were evaluated. The MgH{sub 2} decomposition temperature and energy of activation reduction were measured by temperature programmed desorption (TPD) and differential scanning calorimetry (DSC). The difference in catalytic efficiency between chlorides and fluorides of the various metals studied is presented. The effects of oxidation state, valence and position in the periodic table for selected halides on MgH{sub 2} decomposition temperature were also studied. The best catalysts, from the halides studied, for magnesium hydride decomposition were ZrF{sub 4}, TaF{sub 5}, NbF{sub 5}, VCl{sub 3} and TiCl{sub 3}. (author)

Metal hydride electrode and nickel hydrogen storage battery; Suiso kyuzo gokin denkyoku oyobi nikkeru-suiso chikudenchi

Energy Technology Data Exchange (ETDEWEB)

Kobayashi, Y.; Tamagawa, H. [Shin-Kobe Electric Machinery Co. Ltd., Tokyo (Japan); Ikawa, A.; Muranaka, R. [Hitachi Ltd., Ibaraki (Japan). Hitachi Research Lab.

1996-04-16

Water soluble polymers such as cellulose derivatives and polyvinylalcohol have been used conventionally as binders for metal hydride electrode used for nickel-hydrogen storage batteries. The shortcomings of those binders, however, are low flexibility, and poor binding property for hydrogen absorbing alloy powder and the conductive supporting substrate. This invention relates to the use of ethylene-vinyl copolymer with less than -10{degree}C Tg as the binder for hydrogen absorbing alloy powder. It is desirable that the ethylene-vinylacetate copolymer is selected out of ethylene-vinyl acetate-acryl copolymer and ethylene-vinyl acetate-long chain vinyl ester copolymer, and that the addition is larger than 0.1wt% and less than 1wt% against the weight of hydrogen absorbing alloy in the electrode. The use of this binder results in strong binding of hydrogen absorbing alloy powder to the conductive supporting substrate, providing flexibility as well. 4 figs., 5 tabs.

The Importance of Rare-Earth Additions in Zr-Based AB2 Metal Hydride Alloys

Directory of Open Access Journals (Sweden)

Kwo-Hsiung Young

2016-07-01

Full Text Available Effects of substitutions of rare earth (RE elements (Y, La, Ce, and Nd to the Zr-based AB2 multi-phase metal hydride (MH alloys on the structure, gaseous phase hydrogen storage (H-storage, and electrochemical properties were studied and compared. Solubilities of the RE atoms in the main Laves phases (C14 and C15 are very low, and therefore the main contributions of the RE additives are through the formation of the RENi phase and change in TiNi phase abundance. Both the RENi and TiNi phases are found to facilitate the bulk diffusion of hydrogen but impede the surface reaction. The former is very effective in improving the activation behaviors. −40 °C performances of the Ce-doped alloys are slightly better than the Nd-doped alloys but not as good as those of the La-doped alloys, which gained the improvement through a different mechanism. While the improvement in ultra-low-temperature performance of the Ce-containing alloys can be associated with a larger amount of metallic Ni-clusters embedded in the surface oxide, the improvement in the La-containing alloys originates from the clean alloy/oxide interface as shown in an earlier transmission electron microscopy study. Overall, the substitution of 1 at% Ce to partially replace Zr gives the best electrochemical performances (capacity, rate, and activation and is recommended for all the AB2 MH alloys for electrochemical applications.

High Density Hydrogen Storage System Demonstration Using NaAlH4 Based Complex Compound Hydrides

Energy Technology Data Exchange (ETDEWEB)

Daniel A. Mosher; Xia Tang; Ronald J. Brown; Sarah Arsenault; Salvatore Saitta; Bruce L. Laube; Robert H. Dold; Donald L. Anton

2007-07-27

This final report describes the motivations, activities and results of the hydrogen storage independent project "High Density Hydrogen Storage System Demonstration Using NaAlH4 Based Complex Compound Hydrides" performed by the United Technologies Research Center under the Department of Energy Hydrogen Program, contract # DE-FC36-02AL67610. The objectives of the project were to identify and address the key systems technologies associated with applying complex hydride materials, particularly ones which differ from those for conventional metal hydride based storage. This involved the design, fabrication and testing of two prototype systems based on the hydrogen storage material NaAlH4. Safety testing, catalysis studies, heat exchanger optimization, reaction kinetics modeling, thermochemical finite element analysis, powder densification development and material neutralization were elements included in the effort.

An Investigation on the Persistence of Uranium Hydride during Storage of Simulant Nuclear Waste Packages.

Directory of Open Access Journals (Sweden)

C A Stitt

Full Text Available Synchrotron X-rays have been used to study the oxidation of uranium and uranium hydride when encapsulated in grout and stored in de-ionised water for 10 months. Periodic synchrotron X-ray tomography and X-ray powder diffraction have allowed measurement and identification of the arising corrosion products and the rates of corrosion. The oxidation rates of the uranium metal and uranium hydride were slower than empirically derived rates previously reported for each reactant in an anoxic water system, but without encapsulation in grout. This was attributed to the grout acting as a physical barrier limiting the access of oxidising species to the uranium surface. Uranium hydride was observed to persist throughout the 10 month storage period and industrial consequences of this observed persistence are discussed.

Determination of hydrogen in zirconium hydride and uranium-zirconium hydride by inert gas exraction-gravimetric method

International Nuclear Information System (INIS)

Hoshino, Akira; Iso, Shuichi

1976-01-01

An inert gas extraction-gravimetric method has been applied to the determination of hydrogen in zirconium hydride and uranium-zirconium hydride which are used as neutron moderator and fuel of nuclear safety research reactor (NSRR), respectively. The sample in a graphite-enclosed quartz crucible is heated inductively to 1200 0 C for 20 min in a helium stream. Hydrogen liberated from the sample is oxidized to water by copper(I) oxide-copper(II) oxide at 400 0 C, and the water is determined gravimetrically by absorption in anhydrone. The extraction curves of hydrogen for zirconium hydride and uranium-zirconium hydride samples are shown in Figs. 2 and 3. Hydrogen in the samples is extracted quantitatively by heating at (1000 -- 1250) 0 C for (10 -- 40) min. Recoveries of hydrogen in the case of zirconium hydride were examined as follows: a weighed zirconium rod (5 phi x 6 mm, hydrogen -5 Torr. After the chamber was filled with purified hydrogen to 200 Torr, the rod was heated to 400 0 C for 15 h, and again weighed to determine the increase in weight. Hydrogen in the rod was then determined by the proposed method. The results are in excellent agreement with the increase in weight as shown in Table 1. Analytical results of hydrogen in zirconium hydride samples and an uranium-zirconium hydride sample are shown in Table 2. (auth.)

Nanoindentation measurements of the mechanical properties of zirconium matrix and hydrides in unirradiated pre-hydrided nuclear fuel cladding

International Nuclear Information System (INIS)

Rico, A.; Martin-Rengel, M.A.; Ruiz-Hervias, J.; Rodriguez, J.; Gomez-Sanchez, F.J.

2014-01-01

It is well known that the mechanical properties of the nuclear fuel cladding may be affected by the presence of hydrides. The average mechanical properties of hydrided cladding have been extensively investigated from a macroscopic point of view. In addition, the mechanical and fracture properties of bulk hydride samples fabricated from zirconium plates have also been reported. In this paper, Young’s modulus, hardness and yield stress are measured for each phase, namely zirconium hydrides and matrix, of pre-hydrided nuclear fuel cladding. To this end, nanoindentation tests were performed on ZIRLO samples in as-received state, on a hydride blister and in samples with 150 and 1200 ppm of hydrogen homogeneously distributed along the hoop direction of the cladding. The results show that the measured mechanical properties of the zirconium hydrides and ZIRLO matrix (Young’s modulus, hardness and yield stress) are rather similar. From the experimental data, the hydride volume fraction in the cladding samples with 150 and 1200 ppm was estimated and the average mechanical properties were calculated by means of the rule of mixtures. These values were compared with those obtained from ring compression tests. Good agreement between the results obtained by both methods was found

Centrifugal Compressor Aeroelastic Analysis Code

Science.gov (United States)

Keith, Theo G., Jr.; Srivastava, Rakesh

2002-01-01

Centrifugal compressors are very widely used in the turbomachine industry where low mass flow rates are required. Gas turbine engines for tanks, rotorcraft and small jets rely extensively on centrifugal compressors for rugged and compact design. These compressors experience problems related with unsteadiness of flowfields, such as stall flutter, separation at the trailing edge over diffuser guide vanes, tip vortex unsteadiness, etc., leading to rotating stall and surge. Considerable interest exists in small gas turbine engine manufacturers to understand and eventually eliminate the problems related to centrifugal compressors. The geometric complexity of centrifugal compressor blades and the twisting of the blade passages makes the linear methods inapplicable. Advanced computational fluid dynamics (CFD) methods are needed for accurate unsteady aerodynamic and aeroelastic analysis of centrifugal compressors. Most of the current day industrial turbomachines and small aircraft engines are designed with a centrifugal compressor. With such a large customer base and NASA Glenn Research Center being, the lead center for turbomachines, it is important that adequate emphasis be placed on this area as well. Currently, this activity is not supported under any project at NASA Glenn.

Compressor performance aerodynamics for the user

CERN Document Server

Gresh, Theodore

2001-01-01

Compressor Performance is a reference book and CD-ROM for compressor design engineers and compressor maintenance engineers, as well as engineering students. The book covers the full spectrum of information needed for an individual to select, operate, test and maintain axial or centrifugal compressors. It includes basic aerodynamic theory to provide the user with the ""how's"" and ""why's"" of compressor design. Maintenance engineers will especially appreciate the troubleshooting guidelines offered. Includes many example problems and reference data such as gas propert

FY1995 study of aid system for the elderly and the disabled using metal hydride alloy actuators; 1995 nendo suiso kyuzo gokingata actuator ni yoru kaijo shien system no kaihatsu

Energy Technology Data Exchange (ETDEWEB)

NONE

1997-03-01

Purpose of the project is to develop a transfer aid system for the elderly who need assistance in moving from a bed or a chair. It can make up insufficiency of assistant persons and can help to comfortably move the elderly. It has the highest demand in rehabilitation centers or hospitals. We have been designing an actuator using a metal hydride alloy for more than ten years and have confirmed that the actuator is very useful for developing the transfer. Furthermore, we have designed the transfer from a view point of human interfaces. This research was done under the above background. 1. We studied a comfortable posture for the elderly at an initial phase of standing to design the optimal knee pad using a life-size model of a transfer. Especially, we managed to lighten the burden imposed on the elderly by referring electromyographic signals at lower limbs and ground reaction forces. 2. Since the tactile sensation of the bottom of elderly person's foot gets dull, we designed a foot stage to prevent the elderly from the dull. 3. We determined the optimal mixture rate of a metal hydride alloy and developed an elastic bellows in order to design the actuator used for the transfer aid. 4. We determined the optimal compliance to prevent the elderly from a mechanical shock and designed a mechanism so that the transfer aid can work well. 5. Based on the above results, we developed the transfer aid using the metal hydride actuator. It was ascertained that it can lift a elderly person with 80kg weight by using only 40g alloy. Furthermore, it is proved that the transfer is not heavy (about 20g weight), small, silent, and moves smoothly by a battery on the market. (NEDO)

Identification and characterization of a new Zirconium hydride

International Nuclear Information System (INIS)

Zhao, Z.

2007-01-01

In order to control the integrity of the fuel clad, alloy of zirconium, it is necessary to predict the behavior of zirconium hydrides in the environment (temperature, stress...), at a microscopic scale. A characterization study by TEM of hydrides has been realized. It shows little hydrides about 500 nm, in hydride Zircaloy 4. Then a more detailed study identified a new hydride phase presented in this paper. (A.L.B.)

Compressors selection and sizing

CERN Document Server

Brown, Royce N

2005-01-01

This practical reference provides in-depth information required to understand and properly estimate compressor capabilities and to select the proper designs. Engineers and students will gain a thorough understanding of compression principles, equipment, applications, selection, sizing, installation, and maintenance. The many examples clearly illustrate key aspects to help readers understand the ""real world"" of compressor technology.Compressors: Selection and Sizing, third edition is completely updated with new API standards. Additions requested by readers include a new section on di

Discharge capacity and microstructures of La Mg Pr Al Mn Co Ni alloys for nickel-metal hydride batteries

International Nuclear Information System (INIS)

Casini, J.C.S.; Galdino, G.S.; Ferreira, E.A.; Takiishi, H.; Faria, R.N.

2010-01-01

La 0.7-x Mg x Pr 0.3 Al 0.3 Mn 0.4 Co 0.5 Ni 3.8 (x = 0.0, 0.3 and 0.7) alloys have been investigated aiming the production of negative electrodes for nickel-metal hydride batteries. The alloys employed in this work were used in the as cast state. The results showed that the substitution of magnesium by lanthanum increased the discharge capacity of the Ni-MH batteries. A battery produced with the La 0.4 Mg 0.3 Pr 0.3 Al 0.3 Mn 0.4 Co 0.5 Ni 3.8 alloy shown a high discharge capacity (380mAh/g) also good stability compared to other alloys. The electrode materials were characterized using scanning electron microscopy (SEM) and X-ray diffraction (XRD). (author)

Analytical model for an electrostatically actuated miniature diaphragm compressor

International Nuclear Information System (INIS)

Sathe, Abhijit A; Groll, Eckhard A; Garimella, Suresh V

2008-01-01

This paper presents a new analytical approach for quasi-static modeling of an electrostatically actuated diaphragm compressor that could be employed in a miniature scale refrigeration system. The compressor consists of a flexible circular diaphragm clamped at its circumference. A conformal chamber encloses the diaphragm completely. The membrane and the chamber surfaces are coated with metallic electrodes. A potential difference applied between the diaphragm and the chamber pulls the diaphragm toward the chamber surface progressively from the outer circumference toward the center. This zipping actuation reduces the volume available to the refrigerant gas, thereby increasing its pressure. A segmentation technique is proposed for analysis of the compressor by which the domain is divided into multiple segments for each of which the forces acting on the diaphragm are estimated. The pull-down voltage to completely zip each individual segment is thus obtained. The required voltage for obtaining a specific pressure rise in the chamber can thus be determined. Predictions from the model compare well with other simulation results from the literature, as well as to experimental measurements of the diaphragm displacement and chamber pressure rise in a custom-built setup

Empirical Design Considerations for Industrial Centrifugal Compressors

Directory of Open Access Journals (Sweden)

Cheng Xu

2012-01-01

Full Text Available Computational Fluid Dynamics (CFD has been extensively used in centrifugal compressor design. CFD provides further optimisation opportunities for the compressor design rather than designing the centrifugal compressor. The experience-based design process still plays an important role for new compressor developments. The wide variety of design subjects represents a very complex design world for centrifugal compressor designers. Therefore, some basic information for centrifugal design is still very important. The impeller is the key part of the centrifugal stage. Designing a highly efficiency impeller with a wide operation range can ensure overall stage design success. This paper provides some empirical information for designing industrial centrifugal compressors with a focus on the impeller. A ported shroud compressor basic design guideline is also discussed for improving the compressor range.

Pulse power 350 V nickel-metal hydride battery power-D-005-00181

Science.gov (United States)

Eskra, Michael D.; Ralston, Paula; Salkind, Alvin; Plivelich, Robert F.

Energy-storage devices are needed for applications requiring very high-power over short periods of time. Such devices have various military (rail guns, electromagnetic launchers, and DEW) and commercial applications, such as hybrid electric vehicles, vehicle starting (SLI), and utility peak shaving. The storage and delivery of high levels of burst power can be achieved with a capacitor, flywheel, or rechargeable battery. In order to reduce the weight and volume of many systems they must contain advanced state-of-the-art electrochemical or electromechanical power sources. There is an opportunity and a need to develop energy-storage devices that have improved high-power characteristics compared to existing ultra capacitors, flywheels or rechargeable batteries. Electro Energy, Inc. has been engaged in the development of bipolar nickel-metal hydride batteries, which may fulfil the requirements of some of these applications. This paper describes a module rated at 300 V (255 cells) (6 Ah). The volume of the module is 23 L and the mass is 56 kg. The module is designed to deliver 50 kW pulses of 10 s duration at 50% state-of-charge. Details of the mechanical design of the module, safety considerations, along with the results of initial electrical characterization testing by the customer will be discussed. Some discussion of the possibilities for design optimization is also included.

Interface Enthalpy-Entropy Competition in Nanoscale Metal Hydrides

Directory of Open Access Journals (Sweden)

Nicola Patelli

2018-01-01

Full Text Available We analyzed the effect of the interfacial free energy on the thermodynamics of hydrogen sorption in nano-scaled materials. When the enthalpy and entropy terms are the same for all interfaces, as in an isotropic bi-phasic system, one obtains a compensation temperature, which does not depend on the system size nor on the relative phase abundance. The situation is different and more complex in a system with three or more phases, where the interfaces have different enthalpy and entropy. We also consider the possible effect of elastic strains on the stability of the hydride phase and on hysteresis. We compare a simple model with experimental data obtained on two different systems: (1 bi-phasic nanocomposites where ultrafine TiH2 crystallite are dispersed within a Mg nanoparticle and (2 Mg nanodots encapsulated by different phases.

Oil-Free Compressor

Science.gov (United States)

Fitzjerrell, D. G.; Belver, T. L.; Moore, H. E.

1986-01-01

Compressor pistons moved by eccentric shaft need no lubricants. Compressor has shaft, middle section is eccentric in relation to end sections. Driven by brushless dc motor, shaft turns inner races of set of four cam bearings. Outer cam-bearing races in turn actuate four pistons spaced equally apart, around and along shaft. Each outer bearing race held in position by pressure exerted on it by piston. Because no frictional motion between piston and outer bearing race, lubricant between them unnecessary. Cam bearings themselves contain potted internal lubricant. Originally proposed for use in space, new compressor for refrigerators or freezers does not depend on pool of oil for lubricating its pistons. Operated in any orientation.

Modeling the Effects of Ice Accretion on the Low Pressure Compressor and the Overall Turbofan Engine System Performance

Science.gov (United States)

Veres, Joseph P.; Jorgenson, Philip C. E.; Wright, William B.

2011-01-01

The focus of this study is on utilizing a mean line compressor flow analysis code coupled to an engine system thermodynamic code, to estimate the effects of ice accretion on the low pressure compressor, and quantifying its effects on the engine system throughout a notional flight trajectory. In this paper a temperature range in which engine icing would occur was assumed. This provided a mechanism to locate potential component icing sites and allow the computational tools to add blockages due to ice accretion in a parametric fashion. Ultimately the location and level of blockage due to icing would be provided by an ice accretion code. To proceed, an engine system modeling code and a mean line compressor flow analysis code were utilized to calculate the flow conditions in the fan-core and low pressure compressor and to identify potential locations within the compressor where ice may accrete. In this study, an "additional blockage" due to the accretion of ice on the metal surfaces, has been added to the baseline aerodynamic blockage due to boundary layer, as well as the blade metal blockage. Once the potential locations of ice accretion are identified, the levels of additional blockage due to accretion were parametrically varied to estimate the effects on the low pressure compressor blade row performance operating within the engine system environment. This study includes detailed analysis of compressor and engine performance during cruise and descent operating conditions at several altitudes within the notional flight trajectory. The purpose of this effort is to develop the computer codes to provide a predictive capability to forecast the onset of engine icing events, such that they could ultimately help in the avoidance of these events.

Improved rapidly-quenched hydrogen-absorbing alloys for development of improved-capacity nickel metal hydride batteries

Science.gov (United States)

Ise, Tadashi; Hamamatsu, Takeo; Imoto, Teruhiko; Nogami, Mitsuzo; Nakahori, Shinsuke

The effects of annealing a rapidly-quenched hydrogen-absorbing alloy with a stoichiometric ratio of 4.76 were investigated concerning its hydrogen-absorbing properties, crystal structure and electrochemical characteristics. Annealing at 1073 K homogenized the alloy microstructure and flattened its plateau slope in the P-C isotherms. However, annealing at 1273 K segregated a second phase rich in rare earth elements, increased the hydrogen-absorbing pressure and decreased the hydrogen-absorbing capacity. As the number of charge-discharge cycles increases, the particle size distribution of the rapidly-quenched alloy became broad due to partial pulverization. However, particle size distribution of the rapidly-quenched, annealed, alloy was sharp, since the annealing homogenized the microstructure, thereby improving the cycle characteristics. A high-capacity rectangular nickel metal hydride battery using a rapidly-quenched, annealed, surface-treated alloy for the negative electrode and an active material coated with cobalt compound containing sodium for the positive electrode was developed. The capacity of the resulting battery was 30% greater than that of a conventional battery.

A review of linear compressors for refrigeration

OpenAIRE

Liang, Kun

2017-01-01

Linear compressor has no crank mechanism compared with conventional reciprocating compressor. This allows higher efficiency, oil-free operation, lower cost and smaller size when linear compressors are used for vapour compression refrigeration (VCR) system. Typically, a linear compressor consists of a linear motor (connected to a piston) and suspension springs, operated at resonant frequency. This paper presents a review of linear compressors for refrigeration system. Different designs and mod...

Meridional Considerations of the Centrifugal Compressor Development

Directory of Open Access Journals (Sweden)

C. Xu

2012-01-01

Full Text Available Centrifugal compressor developments are interested in using optimization procedures that enable compressor high efficiency and wide operating ranges. Recently, high pressure ratio and efficiency of the centrifugal compressors require impeller design to pay attention to both the blade angle distribution and the meridional profile. The geometry of the blades and the meridional profile are very important contributions of compressor performance and structure reliability. This paper presents some recent studies of meridional impacts of the compressor. Studies indicated that the meridional profiles of the impeller impact the overall compressor efficiency and pressure ratio at the same rotational speed. Proper meridional profiles can improve the compressor efficiency and increase the overall pressure ratio at the same blade back curvature.

Rapid PMR determination of hydrogen in titanium hydride and dehydrogenated titanium powders

International Nuclear Information System (INIS)

Il'enko, V.S.; Demidenko, L.M.

1987-01-01

Proton magnetic resonance (PMR) enables determining hydrogen quantitatively in titanium hydride and dehydrogenated titanium powders without destroying the specimen and is also more informative than high-temperature extraction methods. PMR provides data on the electron-nuclear interactions and the activation energies for hydrogen diffusion while also providing conclusions on the forms and positives of the hydrogen in the lattice and the binding to the metal atoms. The authors have developed a rapid method for determining hydrogen in titanium hydride and dehydrogenated titanium powders which reduces the analysis time and improves the metrological characteristics. The authors use a YaMR-5535 spectrometer working at 40 MHz upgraded for use with hydrogen in solids. The authors used specimens of mass about 2 g ground to 0.1 mm powder

Flow Range of Centrifugal Compressor Being Extended

Science.gov (United States)

Skoch, Gary J.

2001-01-01

General Aviation will benefit from turbine engines that are both fuel-efficient and reliable. Current engines fall short of their potential to achieve these attributes. The reason is compressor surge, which is a flow stability problem that develops when the compressor is subjected to conditions that are outside of its operating range. Compressor surge can occur when fuel flow to the engine is increased, temporarily back pressuring the compressor and pushing it past its stability limit, or when the compressor is subjected to inlet flow-field distortions that may occur during takeoff and landing. Compressor surge can result in the loss of an aircraft. As a result, engine designers include a margin of safety between the operating line of the engine and the stability limit line of the compressor. Unfortunately, the most efficient operating line for the compressor is usually closer to its stability limit line than it is to the line that provides an adequate margin of safety. A wider stable flow range will permit operation along the most efficient operating line of the compressor, improving the specific fuel consumption of the engine and reducing emissions. The NASA Glenn Research Center is working to extend the stable flow range of the compressor. Significant extension has been achieved in axial compressors by injecting air upstream of the compressor blade rows. Recently, the technique was successfully applied to a 4:1 pressure ratio centrifugal compressor by injecting streams of air into the diffuser. Both steady and controlled unsteady injection were used to inject air through the diffuser shroud surface and extend the range. Future work will evaluate the effect of air injection through the diffuser hub surface and diffuser vanes with the goal of maximizing the range extension while minimizing the amount of injected air that is required.

Simultaneous determination of hydride and non-hydride forming elements by inductively coupled plasma optical emission spectrometry

Energy Technology Data Exchange (ETDEWEB)

Benzo, Z. [Instituto Venezolano de Investigaciones Cientificas, IVIC, Altos de Pipe, Caracas (Venezuela, Bolivarian Republic of); Matos-Reyes, M.N.; Cervera, M.L.; Guardia, M. de la, E-mail: m.luisa.cervera@uv.es [Department of Analytical Chemistry, University of Valencia, Valencia (Spain)

2011-09-15

The operating characteristics of a dual nebulization system were studied including instrumental and chemical conditions for the hydride generation and analytical figures of merit for both, hydride and non hydride forming elements. Analytical performance of the nebulization system was characterized by detection limits from 0.002 to 0.0026 {mu}g mL{sup -1} for the hydride forming elements and between 0.0034 and 0.0121 {mu}g mL{sup -1} for the non-hydride forming elements, relative standard deviation for 10 replicate measurements at 0.25 mg L{sup -1} level and recovery percentages between 97 and 103%. The feasibility of the system was demonstrated in the simultaneous determination of Ca, Cd, Co, Cr, Cu, Fe, Mg, Mn, Mo, Ni, Zn, As, Bi, Sb, Se, and Te in the NIST 1549 (non-fat milk powder), NIST 1570a (spinach leaves), DORM-2 (dogfish muscle) and TORT-2 (lobster hepatopancreas) certified samples for trace elements. Results found were in good agreement with the certified ones. (author)

Study on the surface reaction of uranium metal in hydrogen atmosphere with XPS

International Nuclear Information System (INIS)

Wang Xiaolin; Fu Yibei; Xie Renshou; Zuo Changming; Zhao Chunpei; Chen Hong

1998-01-01

The surface reactions of uranium metal in hydrogen atmosphere at 25 degree C and 200 degree C and effects of temperature and carbon monoxide to the hydriding reaction have been studied by X-ray photoelectron spectroscopy (XPS). The reaction between H 2 and uranium metal at 25 degree C leads to the further oxidation of surface layer of metal due to traces of water vapor. At 200 degree C, it may lead to the hydriding reaction of uranium and the hydriding increases with increasing exposure to H 2 in the initial stages. The U4f 7/2 binding energy of UH 3 has been found to be 378.6 eV. Investigation indicates carbon monoxide inhibits both the hydriding reaction and oxidation on the condition of H 2 -CO atmosphere

XPS study on the surface reaction of uranium metal in H2 and H2-CO atmospheres

International Nuclear Information System (INIS)

Wang Xiaolin; Fu Yibei; Xie Renshou

1996-04-01

The surface reactions of uranium metal in H 2 and H 2 -CO atmospheres and the effects of temperature and CO on the hydriding reaction have been studied by X-ray photoelectron spectroscopy (XPS). The reaction between commercial H 2 and uranium metal at 25 degree C leads mainly to the further oxidation of surface layer of metal due to traces of water vapour. At 200 degree C, it may lead to the hydriding reaction of uranium and the hydriding increases with increasing the exposure of H 2 . Investigation indicates CO inhibits both the hydriding reaction and oxidation on the condition of H 2 -CO atmospheres. (13 refs., 10 figs.)

Algorithm for Controlling a Centrifugal Compressor

Science.gov (United States)

Benedict, Scott M.

2004-01-01

An algorithm has been developed for controlling a centrifugal compressor that serves as the prime mover in a heatpump system. Experimental studies have shown that the operating conditions for maximum compressor efficiency are close to the boundary beyond which surge occurs. Compressor surge is a destructive condition in which there are instantaneous reversals of flow associated with a high outlet-to-inlet pressure differential. For a given cooling load, the algorithm sets the compressor speed at the lowest possible value while adjusting the inlet guide vane angle and diffuser vane angle to maximize efficiency, subject to an overriding requirement to prevent surge. The onset of surge is detected via the onset of oscillations of the electric current supplied to the compressor motor, associated with surge-induced oscillations of the torque exerted by and on the compressor rotor. The algorithm can be implemented in any of several computer languages.

Modeling of scroll compressors - Improvements

Energy Technology Data Exchange (ETDEWEB)

Duprez, Marie-Eve; Dumont, Eric; Frere, Marc [Thermodynamics Department, Universite de Mons - Faculte Polytechnique, 31 bd Dolez, 7000 Mons (Belgium)

2010-06-15

This paper presents an improvement of the scroll compressors model previously published by. This improved model allows the calculation of refrigerant mass flow rate, power consumption and heat flow rate that would be released at the condenser of a heat pump equipped with the compressor, from the knowledge of operating conditions and parameters. Both basic and improved models have been tested on scroll compressors using different refrigerants. This study has been limited to compressors with a maximum electrical power of 14 kW and for evaporation temperatures ranging from -40 to 15 C and condensation temperatures from 10 to 75 C. The average discrepancies on mass flow rate, power consumption and heat flow rate are respectively 0.50%, 0.93% and 3.49%. Using a global parameter determination (based on several refrigerants data), this model can predict the behavior of a compressor with another fluid for which no manufacturer data are available. (author)

Research Update: A hafnium-based metal-organic framework as a catalyst for regioselective ring-opening of epoxides with a mild hydride source

International Nuclear Information System (INIS)

Stephenson, Casey J.; Hassan Beyzavi, M.; Klet, Rachel C.; Hupp, Joseph T.; Farha, Omar K.

2014-01-01

Reaction of styrene oxide with sodium cyanoborohydride and a catalytic amount of Hf-NU-1000 yields the anti-Markovnikov product, 2-phenylethanol, with over 98% regioselectivity. On the other hand, propylene oxide is ring opened in a Markovnikov fashion to form 2-propanol with 95% regioselectivity. Both styrene oxide and propylene oxide failed to react with sodium cyanoborohydride without the addition of Hf-NU-1000 indicative of the crucial role of Hf-NU-1000 as a catalyst in this reaction. To the best of our knowledge, this is the first report of the use of a metal-organic framework material as a catalyst for ring-opening of epoxides with hydrides

Displacement compressors - acceptance tests

CERN Document Server

International Organization for Standardization. Geneva

1996-01-01

ISO 1217:2009 specifies methods for acceptance tests regarding volume rate of flow and power requirements of displacement compressors. It also specifies methods for testing liquid-ring type compressors and the operating and testing conditions which apply when a full performance test is specified.

Rare earth element recycling from waste nickel-metal hydride batteries

International Nuclear Information System (INIS)

Yang, Xiuli; Zhang, Junwei; Fang, Xihui

2014-01-01

Highlights: • Leaching kinetics of REEs has rarely been reported. • A new method, including hydrochloric acid leaching and oxalic acid precipitation, was proposed. • REEs recovery rate of 95.16% and pure rare earth oxides of 99% were obtained. • Leaching process was controlled by chemical reaction. • The kinetic equation was determined. - Abstract: With an increase in number of waste nickel-metal hydride batteries, and because of the importance of rare earth elements, the recycling of rare earth elements is becoming increasingly important. In this paper, we investigate the effects of temperature, hydrochloric acid concentration, and leaching time to optimize leaching conditions and determine leach kinetics. The results indicate that an increase in temperature, hydrochloric acid concentration, and leaching time enhance the leaching rate of rare earth elements. A maximum rare earth elements recovery of 95.16% was achieved at optimal leaching conditions of 70 °C, solid/liquid ratio of 1:10, 20% hydrochloric acid concentration, −74 μm particle size, and 100 min leaching time. The experimental data were best fitted by a chemical reaction-controlled model. The activation energy was 43.98 kJ/mol and the reaction order for hydrochloric acid concentration was 0.64. The kinetic equation for the leaching process was found to be: 1−(1−x) 1/3 =A/ρr 0 [HCl] 0.64 exp((−439,800)/(8.314T) )t. After leaching and filtration, by adding saturated oxalic solution to the filtrate, rare earth element oxalates were obtained. After removing impurities by adding ammonia, filtering, washing with dilute hydrochloric acid, and calcining at 810 °C, a final product of 99% pure rare earth oxides was obtained

Decontamination of U-metal surface by an oxidation etching system

Energy Technology Data Exchange (ETDEWEB)

Stout, R.B.; Kansa, E.J.; Shaffer, R.J.; Weed, H.C. [California Univ., Livermore, CA (United States). Lawrence Livermore National Lab

2001-07-01

A surface treatment to remove surface contamination from uranium (U) metal and/or hydrides of uranium and heavy metals (HM) from U-metal parts is described. In the case of heavy metal atomic contamination on a surface, and potentially several atomic layers beneath, the surface oxidation treatment combines both chemical and chemically driven mechanical processes. The chemical process is a controlled temperature-time oxidation process to create a thin film of uranium oxide (UO{sub 2} and higher oxides) on the U-metal surface. The chemically driven mechanical process is strain induced by the volume increase as the U-metal surface transforms to a UO{sub 2} surface film. These volume strains are significantly large to cause surface failure spalling/scale formation and thus, removal of a U-oxide film that contains the HM-contaminated surface. The case of a HM-hydride surface contamination layer can be treated similarly by using inert hot gas to decompose the U-hydrides and/or HM-hydrides that are contiguous with the surface. A preliminary analysis to design and to plan for a sequence of tests is developed. The tests will provide necessary and sufficient data to evaluate the effective implementation and operational characteristics of a safe and reliable system. The following description is limited to only a surface oxidation process for HM-decontamination. (authors)

Synthesis and reactions of imines of α,β-ethylenic silicon-containing aldehydes with complex metal hydrides

International Nuclear Information System (INIS)

Surnin, V.A.; Stadnichuk, M.D.

1986-01-01

Imines of 3-trimethylsilyl-2-propenal or its hydrocarbon analog are reduced chemoselectively at the C=N double bond by sodium borohydride. The direction of lithium aluminum hydride reduction of these imines is not influenced by the nature of the element attached to the C=C bond silicon versus carbon, but rather is determined by the nature of the radical group attached to the nitrogen atom; N-arylimines undergo addition with lithium aluminum hydride at the C=N bond exclusively, whereas for N-alkylimines the addition reactions occur either partially or in full in the 1,4-position, depending on the reaction conditions, to give imines of saturated aldehydes after demetallation

Comprehensive model of a hermetic reciprocating compressor

Science.gov (United States)

Yang, B.; Ziviani, D.; Groll, E. A.

2017-08-01

A comprehensive simulation model is presented to predict the performance of a hermetic reciprocating compressor and to reveal the underlying mechanisms when the compressor is running. The presented model is composed of sub-models simulating the in-cylinder compression process, piston ring/journal bearing frictional power loss, single phase induction motor and the overall compressor energy balance among different compressor components. The valve model, leakage through piston ring model and in-cylinder heat transfer model are also incorporated into the in-cylinder compression process model. A numerical algorithm solving the model is introduced. The predicted results of the compressor mass flow rate and input power consumption are compared to the published compressor map values. Future work will focus on detailed experimental validation of the model and parametric studies investigating the effects of structural parameters, including the stroke-to-bore ratio, on the compressor performance.

Characterisation of hydrides in a zirconium alloy, by EBSD

International Nuclear Information System (INIS)

Ubhi, H.S.; Larsen, K.

2012-01-01

Zirconium alloys are used in nuclear reactors owing to their low capture cross-section for thermal neutrons and good mechanical and corrosion properties. However, they do suffer from delayed hydrogen cracking (DHC) due to formation of hydride particles. This study shows how the electron back-scatter diffraction (EBSD) technique can be used to characterise hydrides and their orientation relationship with the matrix. Hydrided EB weld specimens were prepared by electro-polishing, characterised using Oxford instruments AZtecHKL EBSD apparatus and software attached to a FEG SEM. Hydrides were found to exist as fine intra granular plates and having the Blackburn orientation relationship, i.e. (0002)Zr//(111)hydride and (1120)Zr//(1-10)hydride. The hydrides were also found to contain sigma 3 boundaries as well as local misorientations. (author)

Hermetically Sealed Compressor

Science.gov (United States)

Holtzapple, Mark T.

1994-01-01

Proposed hermetically sealed pump compresses fluid to pressure up to 4,000 atm (400 MPa). Pump employs linear electric motor instead of rotary motor to avoid need for leakage-prone rotary seals. In addition, linear-motor-powered pump would not require packings to seal its piston. Concept thus eliminates major cause of friction and wear. Pump is double-ended diaphragm-type compressor. All moving parts sealed within compressor housing.

New technology of subsea and offshore compressor

Energy Technology Data Exchange (ETDEWEB)

Almasi, Amin

2012-09-15

Subsea compressor is a hot topic. Subsea compressor offers tremendous potentials, but also some obstacles. Active magnetic bearings installed inside the process gas allow the elimination of lubrication and seal systems. High-speed permanent- magnet motor directly drives centrifugal compressor to meet optimum speed, eliminating gear box. This design offers inherent machinery health monitoring features and very compact and reliable train. New technology of hermitically sealed direct drive centrifugal compressor for offshore and subsea applications are discussed and case studies for horizontal and vertical compressor train arrangements are presented. (orig.)

Performance test of 100 W linear compressor

Energy Technology Data Exchange (ETDEWEB)

Ko, J; Ko, D. Y.; Park, S. J.; Kim, H. B.; Hong, Y. J.; Yeom, H. K. [Korea Institute of Machinery and Materials, Daejeon(Korea, Republic of)

2013-09-15

In this paper, we present test results of developed 100 W class linear compressor for Stirling-type pulse tube refrigerator. The fabricated linear compressor has dual-opposed configuration, free piston and moving magnet type linear motor. Power transfer, efficiency and required pressure waveform are predicted with designed and measured specifications. In experiments, room temperature test with flow impedance is conducted to evaluate performance of developed linear compressor. Flow impedance is loaded to compressor with metering valve for flow resistance, inertance tube for flow inertance and buffer volumes for flow compliance. Several operating parameters such as input voltage, current, piston displacement and pressure wave are measured for various operating frequency and fixed input current level. Behaviors of dynamics and performance of linear compressor as varying flow impedance are discussed with measured experimental results. The developed linear compressor shows 124 W of input power, 86 % of motor efficiency and 60 % of compressor efficiency at its resonant operating condition.

Using helical compressors for coke gas condensation

Energy Technology Data Exchange (ETDEWEB)

Privalov, V E; Rezunenko, Yu I; Lelyanov, N V; Zarnitzkii, G Eh; Gordienko, A A; Derebenko, I F; Venzhega, A G; Leonov, N P; Gorokhov, N N

1982-08-01

Coke oven gas compression is discussed. Presently used multilevel piston compressors are criticized. The paper recommends using helical machines which combine advantages of using volume condensing compressors and compact high-efficiency centrifugal machines. Two kinds of helical compressors are evaluated: dry and oil-filled; their productivities and coke oven gas chemical composition are analyzed. Experiments using helical compressors were undertaken at the Yasinovskii plant. Flowsheet of the installation is shown. Performance results are given in a table. For all operating conditions content of insolubles in oil compounds is found to be lower than the acceptable value (0.08%). Compressor productivity measurements with variable manifold pressure are evaluated. Figures obtained show that efficient condensation of raw coke oven gas is possible. Increasing oil-filled compressor productivity is recommended by decreasing amount of oil injected and simultaneously increasing rotation speed. The dry helical compressor with water seal is found to be most promising for raw coke oven gas condensation. (10 refs.)

An exergy method for compressor performance analysis

Energy Technology Data Exchange (ETDEWEB)

McGovern, J A; Harte, S [Trinity Coll., Dublin (Ireland)

1995-07-01

An exergy method for compressor performance analysis is presented. The purpose of this is to identify and quantify defects in the use of a compressor`s shaft power. This information can be used as the basis for compressor design improvements. The defects are attributed to friction, irreversible heat transfer, fluid throttling, and irreversible fluid mixing. They are described, on a common basis, as exergy destruction rates and their locations are identified. The method can be used with any type of positive displacement compressor. It is most readily applied where a detailed computer simulation program is available for the compressor. An analysis of an open reciprocating refrigeration compressor that used R12 refrigerant is given as an example. The results that are presented consist of graphs of the instantaneous rates of exergy destruction according to the mechanisms involved, a pie chart of the breakdown of the average shaft power wastage by mechanism, and a pie chart with a breakdown by location. (author)

40 CFR 63.1012 - Compressor standards.

Science.gov (United States)

2010-07-01

... is equipped with a system to capture and transport leakage from the compressor drive shaft seal to a... in the referencing subpart. (b) Seal system standard. Each compressor shall be equipped with a seal..., except as provided in § 63.1002(b) and paragraphs (e) and (f) of this section. Each compressor seal...

Fairchild 7B compressor model

International Nuclear Information System (INIS)

Foster, R.E.; Neely, R.S.

1987-01-01

The Fairchild 7B centrifugal compressor used in the X-326 isotopic ''top'' cascade at the Portsmouth Gaseous Diffusion Plant has been modeled using a proprietary computer code called COMPAL by Concepts E.T.I., Inc. of Norwich, VT. The 7B compressor is described and some results of the modeling calculations are presented. Performance characteristics curves (PR/sub b/vs. flow and PR/sub a/) are included for UF 6 gas for two compressor inlet temperatures

Air compressor efficiency in a Vietnamese enterprise

Energy Technology Data Exchange (ETDEWEB)

Yang, Ming [3E and T International, Suite 1506, Building No. 10, Luo Ma Shi Street, Xuan Wu District, Beijing 100052 (China)

2009-06-15

Compressed air systems in a Vietnamese footwear manufacturing enterprise consume about 10% of enterprise's total electric power supply. Energy efficiency of these air compressor systems, either equipped with new and efficient compressors or old and inefficient ones, can only reach between 5% and 10%. In other words, regardless whatever air compressors were installed, energy loss from the compressor systems was over 80%. This study discovered that energy loss was due to non-optimized operations of the air compressor systems and air leakages. The objectives of the paper are to uncover energy saving potential in Vietnamese air compressor systems, demonstrate methodologies used in the auditing and assessment, share auditing and assessment results, and serve a guide on how to analyze energy efficiency in a compressed air system. This paper concludes that energy efficiency investment in air compressor systems in the Vietnamese enterprise could be extremely cost-effective. If the enterprise invests USD 84,000 in the air compressors to improve efficiency performance, the investment capital will be recovered in about six months. The net present value of the investment will be about USD 864,000 at a discount rate of 12%. (author)

Air compressor efficiency in a Vietnamese enterprise

Energy Technology Data Exchange (ETDEWEB)

Yang Ming [3E and T International, Suite 1506, Building No. 10, Luo Ma Shi Street, Xuan Wu District, Beijing 100052 (China)], E-mail: ming.yang7@gmail.com

2009-06-15

Compressed air systems in a Vietnamese footwear manufacturing enterprise consume about 10% of enterprise's total electric power supply. Energy efficiency of these air compressor systems, either equipped with new and efficient compressors or old and inefficient ones, can only reach between 5% and 10%. In other words, regardless whatever air compressors were installed, energy loss from the compressor systems was over 80%. This study discovered that energy loss was due to non-optimized operations of the air compressor systems and air leakages. The objectives of the paper are to uncover energy saving potential in Vietnamese air compressor systems, demonstrate methodologies used in the auditing and assessment, share auditing and assessment results, and serve a guide on how to analyze energy efficiency in a compressed air system. This paper concludes that energy efficiency investment in air compressor systems in the Vietnamese enterprise could be extremely cost-effective. If the enterprise invests USD 84,000 in the air compressors to improve efficiency performance, the investment capital will be recovered in about six months. The net present value of the investment will be about USD 864,000 at a discount rate of 12%.

Air compressor efficiency in a Vietnamese enterprise

International Nuclear Information System (INIS)

Yang Ming

2009-01-01

Compressed air systems in a Vietnamese footwear manufacturing enterprise consume about 10% of enterprise's total electric power supply. Energy efficiency of these air compressor systems, either equipped with new and efficient compressors or old and inefficient ones, can only reach between 5% and 10%. In other words, regardless whatever air compressors were installed, energy loss from the compressor systems was over 80%. This study discovered that energy loss was due to non-optimized operations of the air compressor systems and air leakages. The objectives of the paper are to uncover energy saving potential in Vietnamese air compressor systems, demonstrate methodologies used in the auditing and assessment, share auditing and assessment results, and serve a guide on how to analyze energy efficiency in a compressed air system. This paper concludes that energy efficiency investment in air compressor systems in the Vietnamese enterprise could be extremely cost-effective. If the enterprise invests USD 84,000 in the air compressors to improve efficiency performance, the investment capital will be recovered in about six months. The net present value of the investment will be about USD 864,000 at a discount rate of 12%.

Electrochemical Hydrogen Compressor

Energy Technology Data Exchange (ETDEWEB)

Lipp, Ludwig [FuelCell Energy, Inc., Torrington, CT (United States)

2016-01-21

Conventional compressors have not been able to meet DOE targets for hydrogen refueling stations. They suffer from high capital cost, poor reliability and pose a risk of fuel contamination from lubricant oils. This project has significantly advanced the development of solid state hydrogen compressor technology for multiple applications. The project has achieved all of its major objectives. It has demonstrated capability of Electrochemical Hydrogen Compression (EHC) technology to potentially meet the DOE targets for small compressors for refueling sites. It has quantified EHC cell performance and durability, including single stage hydrogen compression from near-atmospheric pressure to 12,800 psi and operation of EHC for more than 22,000 hours. Capital cost of EHC was reduced by 60%, enabling a path to meeting the DOE cost targets for hydrogen compression, storage and delivery ($2.00-2.15/gge by 2020).

Refrigeration system having standing wave compressor

Science.gov (United States)

Lucas, Timothy S.

1992-01-01

A compression-evaporation refrigeration system, wherein gaseous compression of the refrigerant is provided by a standing wave compressor. The standing wave compressor is modified so as to provide a separate subcooling system for the refrigerant, so that efficiency losses due to flashing are reduced. Subcooling occurs when heat exchange is provided between the refrigerant and a heat pumping surface, which is exposed to the standing acoustic wave within the standing wave compressor. A variable capacity and variable discharge pressure for the standing wave compressor is provided. A control circuit simultaneously varies the capacity and discharge pressure in response to changing operating conditions, thereby maintaining the minimum discharge pressure needed for condensation to occur at any time. Thus, the power consumption of the standing wave compressor is reduced and system efficiency is improved.

Modification of a compressor performance test bench for liquid slugging observation in refrigeration compressors

Science.gov (United States)

Ola, Max; Thomas, Christiane; Hesse, Ullrich

2017-08-01

Compressor performance test procedures are defined by the standard DIN EN 13771, wherein a variety of possible calorimeter and flow rate measurement methods are suggested. One option is the selection of two independent measurement methods. The accuracies of both selected measurement methods are essential. The second option requires only one method. However the measurement accuracy of the used device has to be verified and recalibrated on a regular basis. The compressor performance test facility at the Technische Universitaet Dresden uses a calibrated flow measurement sensor, a hot gas bypass and a mixed flow heat exchanger. The test bench can easily be modified for tests of various compressor types at different operating ranges and with various refrigerants. In addition, the modified test setup enables the investigation of long term liquid slug and its effects on the compressor. The modification comprises observational components, adjustments of the control system, safety measures and a customized oil recirculation system for compressors which do not contain an integrated oil sump or oil level regulation system. This paper describes the setup of the test bench, its functional principle, the key modifications, first test results and an evaluation of the energy balance.

SYNTHESIS AND STRUCTURE OF BIS(PHENYLTETRAMETHYLCYCLOPENTADIENYL)TITANIUM(III) HYDRIDE - THE FIRST MONOMERIC BIS(CYCLOPENTADIENYL)TITANIUM(III) HYDRIDE : The First Monomeric Bis(cyclopentadienyl)titanium(III) Hydride

NARCIS (Netherlands)

de Wolf, J.M.; Meetsma, A.; Teuben, J.H

1995-01-01

The first structurally characterized monomeric bis(cyclopentadienyl)titanium(III) hydride, (C(5)PhMe(4))(2)TiH (4), was synthesized by hydrogenolysis of (C(5)PhMe(4))(2)TiMe (5). Hydride 4 was found to be a monomeric bent sandwich by X-ray diffraction methods, and the pentamethylcyclopentadienyl

Heat pretreatment-induced activation of gadolinium surfaces towards the initial precipitation of hydrides

International Nuclear Information System (INIS)

Benamar, G.; Schweke, D.; Shamir, N.; Zalkind, S.; Livneh, T.; Danon, A.; Kimmel, G.; Mintz, M.H.

2010-01-01

A vacuum heat pretreatment is applied, in order to enhance the reactivity of hydride-forming metals towards hydrogen reaction. For gadolinium, as for other rare-earth metals and some actinides, pretreatment temperatures of about 470 K are sufficient to induce such activation. The different factors that may be involved in that activation mechanism are identified and analyzed for gadolinium and their role is evaluated. It is concluded that the most prominent effect is desorption of surface hydroxyl groups, which impede the dissociative chemisorptions of hydrogen.

Discharge capacity and microstructures of La Mg Pr Al Mn Co Ni alloys for nickel-metal hydride batteries

Energy Technology Data Exchange (ETDEWEB)

Casini, J.C.S.; Galdino, G.S.; Ferreira, E.A.; Takiishi, H.; Faria, R.N., E-mail: jcasini@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (DM/IPEN/CNEN-SP), Sao Paulo, SP (Brazil). Dept. de Metalurgia

2010-07-01

La{sub 0.7-x}Mg{sub x}Pr{sub 0.3}Al{sub 0.3}Mn{sub 0.4}Co{sub 0.5}Ni{sub 3.8} (x = 0.0, 0.3 and 0.7) alloys have been investigated aiming the production of negative electrodes for nickel-metal hydride batteries. The alloys employed in this work were used in the as cast state. The results showed that the substitution of magnesium by lanthanum increased the discharge capacity of the Ni-MH batteries. A battery produced with the La{sub 0.4}Mg{sub 0.3}Pr{sub 0.3}Al{sub 0.3}Mn{sub 0.4}Co{sub 0.5}Ni{sub 3.8} alloy shown a high discharge capacity (380mAh/g) also good stability compared to other alloys. The electrode materials were characterized using scanning electron microscopy (SEM) and X-ray diffraction (XRD). (author)

Hydrogen storage alloy electrode for a metal-hydride alkaline battery; Kinzoku-suisokabutsu arukari chikudenchiyo no suiso kyuzo gokin denkyoku

Energy Technology Data Exchange (ETDEWEB)

Matsuura, Y.; Kuroda, Y.; Higashiyama, N.; Kimoto, M.; Nogami, M.; Nishio, K.; Saito, T.

1996-07-16

This invention aims to present a hydrogen storage alloy electrode which gives a metal-hydride alkaline battery with a high discharge characteristics at an initial stage of the charge and discharge cycle and excellent charge and discharge cycle characteristics. Thin belt-like misch metal(Mm)-nickel hydrogen storage alloy lumps with a CaCu5 type crystal structure and with dissolved boron or carbon as replaced atoms of nickel in a supersaturated state are obtained by quenching and solidification of molten Mm-Ni hydrogen storage alloy with addition of boron or carbon in 0.005 to 0.150 molar ratio to 1 mole of Mm by a single or dual role method, and annealed in an inert gas or in vacuum at a temperature of 620 to 1000{degree}C for a prescribed time to separate out a boron compound as a second phase, followed by pulverization to produce the alloy powder which is used as a hydrogen storage alloy material. The presence of the second phase promotes cracking of the alloy at an early stage of the charge and discharge cycle and suppresses generation of fine powder in the following charge and discharge cycles. 2 figs., 5 tabs.

40 CFR 63.164 - Standards: Compressors.

Science.gov (United States)

2010-07-01

... from the compressor drive shaft seal back to a process or a fuel gas system or to a control device that... compressor shall be equipped with a seal system that includes a barrier fluid system and that prevents... paragraphs (h) and (i) of this section. (b) Each compressor seal system as required in paragraph (a) of this...

Characterization of Multiflux Axial Compressors

International Nuclear Information System (INIS)

Brasnarof, Daniel; Kyung Kyu-Hyung; Rivarola, Martin; Gonzalez Jose; Florido, Pablo; Orellano, Pablo; Bergallo, Juan

2003-01-01

In the present work the results of analytical models of performance are compared with experimental data acquired in the multi flux axial compressor test facility, built in The Pilcaniyeu Technological Complex for the SIGMA project.We describe the experimental circuit and the data of the dispersion inside the axial compressor obtained using a tracer gas through one of the annular inlets.The attained results can be used to validate the design code for the multi flux axial compressors and SIGMA industrial plant

A comparison of the smeared-dislocation and super-dislocation description of a hydrided region in the context of modelling delayed hydride cracking initiation

International Nuclear Information System (INIS)

Smith, E.

1994-01-01

In quantifying the stress distribution within a hydrided region in the context of modelling delayed hydride cracking (DHC) initiation in zirconium alloys, this paper highlights the desirability of accounting for image effects, i.e. the interaction between the hydrided region and any free surface, for example a sharp crack, blunt notch or planar surface. The super-dislocation representation of a finite thickness hydrided region is ideal for accounting for image effects. It also adequately accounts for the finite thickness, t, of a hydrided region provided, as is the case in practice, we are concerned with the stress value within the hydride at distances ≥ 0.25 t from an end of the region. (Author)

Development of battery management system for nickel-metal hydride batteries in electric vehicle applications

Science.gov (United States)

Jung, Do Yang; Lee, Baek Haeng; Kim, Sun Wook

Electric vehicle (EV) performance is very dependent on traction batteries. For developing electric vehicles with high performance and good reliability, the traction batteries have to be managed to obtain maximum performance under various operating conditions. Enhancement of battery performance can be accomplished by implementing a battery management system (BMS) that plays an important role in optimizing the control mechanism of charge and discharge of the batteries as well as monitoring the battery status. In this study, a BMS has been developed for maximizing the use of Ni-MH batteries in electric vehicles. This system performs several tasks: the control of charging and discharging, overcharge and over-discharge protection, the calculation and display of state-of-charge (SOC), safety, and thermal management. The BMS is installed in and tested in a DEV5-5 electric vehicle developed by Daewoo Motor Co. and the Institute for Advanced Engineering in Korea. Eighteen modules of a Panasonic nickel-metal hydride (Ni-MH) battery, 12 V, 95 A h, are used in the DEV5-5. High accuracy within a range of 3% and good reliability are obtained. The BMS can also improve the performance and cycle-life of the Ni-MH battery peak, as well as the reliability and the safety of the electric vehicles.

Actuation of Pneumatic Artificial Muscle via Hydrogen Absorption/Desorption of Metal Hydride-LaNi5

Directory of Open Access Journals (Sweden)

Thanana Nuchkrua

2015-01-01

Full Text Available This paper presents experimental studies on mechanical actuations of a pneumatic artificial muscle (PAM, which is driven by hydrogen gas based metal hydride (MH. The dynamic performances of hydrogen absorption/desorption, taking place within a MH reactor, are controlled via implementing cooling/heating effects of a thermoelectric module (TEM. Hydrogen pressure is applied as a driving force to commanding work outputs of the PAM as desired mechanical actuations. Due to strong inherent nonlinearity, a conventional proportional integral derivative (PID control law is not capable of regulating thermodynamic variables of the HM reaction according to desired performances of the PAM. In this study, the fuzzy adaptive PID control is proposed in manipulating the MH reaction via the TEM. This viability of the proposed methodology is confirmed by the fact that the gains of PID control law are adapted by fuzzy rule-based tuning scheme at various operating conditions of the MH reactor. The experimental results show that the proposed control technique is much more effective than a PID control in both transient and steady state performances of the MH reactor for servo mechanical actuation of the PAM.

A helium regenerative compressor

International Nuclear Information System (INIS)

Swift, W.L.; Nutt, W.E.; Sixsmith, H.

1994-01-01

This paper discusses the design and performance of a regenerative compressor that was developed primarily for use in cryogenic helium systems. The objectives for the development were to achieve acceptable efficiency in the machine using conventional motor and bearing technology while reducing the complexity of the system required to control contamination from the lubricants. A single stage compressor was built and tested. The compressor incorporates aerodynamically shaped blades on a 218 mm (8.6 inches) diameter impeller to achieve high efficiency. A gas-buffered non-contact shaft seal is used to oppose the diffusion of lubricant from the motor bearings into the cryogenic circuit. Since it is a rotating machine, the flow is continuous and steady, and the machine is very quiet. During performance testing with helium, the single stage machine has demonstrated a pressure ratio of 1.5 at a flow rate of 12 g/s with measured isothermal efficiencies in excess of 30%. This performance compares favorably with efficiencies generally achieved in oil flooded screw compressors

Characteristics of hydride precipitation and reorientation in spent-fuel cladding

International Nuclear Information System (INIS)

Chung, H.M.; Daum, R.S.; Hiller, J.M.; Billone, M.C.

2002-01-01

Transmission electron microscopy (TEM) was used to examine Zircaloy fuel cladding, either discharged from several PWRs and a BWR after irradiation to fluence levels of 3.3 to 8.6 X 10 21 n cm -2 (E > 1 MeV) or hydrogen-charged and heat-treated under stress to produce radial hydrides; the goal was to determine the microstructural and crystallographic characteristics of hydride precipitation. Morphologies, distributions, and habit planes of various types of hydrides were determined by stereo-TEM. In addition to the normal macroscopic hydrides commonly observed by optical microscopy, small 'microscopic' hydrides are present in spent-fuel cladding in number densities at least a few orders of magnitude greater than that of macroscopic hydrides. The microscopic hydrides, observed to be stable at least up to 333 deg C, precipitate in association with -type dislocations. While the habit plane of macroscopic tangential hydrides in the spent-fuel cladding is essentially the same as that of unirradiated unstressed Zircaloys, i.e., the [107] Zr plane, the habit plane of tangential hydrides that precipitate under high tangential stress is the [104] Zr plane. The habit plane of radial hydrides that precipitate under tangential stress is the [011] Zr pyramidal plane, a naturally preferred plane for a cladding that has 30 basal-pole texture. Effects of texture on the habit plane and the threshold stress for hydride reorientation are also discussed. (authors)

Initiation of delayed hydride cracking in zirconium-2.5 wt% niobium

International Nuclear Information System (INIS)

Shalabi, A.F.; Meneley, D.A.

1990-01-01

Delayed hydride cracking in zirconium alloys is caused by the repeated precipitation and cracking of brittle hydrides. The growth kinetic of the hydrides have been measured to evaluate the critical hydride length for crack initiation. Hydride growth leading to crack initiation follows an approximate (time) 1/3 law on the average; crack propagation proceeds in a stepwise fashion. The critical length of hydride for crack initiation increases with stress and temperature. The fracture criterion for crack initiation predicts the critical hydride length at a give stress level and temperature. The fracture initiation mechanism of the hydride confirms the temperature effects for heating and cooling cycles under services loads. (orig.)

Low-Vibration Oscillating Compressor

Science.gov (United States)

Studer, P. A.

1984-01-01

Oscillating compressor momentum compensated: produces little vibration in its supporting structure. Compressure requires no lubrication and virtually free of wear. Compresses working fluids such as helium, nitrogen or chlorfluorocarbons for Stirling-cycle refrigeration or other purposes. Compressor includes two mutually opposed ferromagnetic pistons of same shape and mass. Electromagnetic flux links both pistons, causing magnetic attraction between them.

33 CFR 154.826 - Vapor compressors and blowers.

Science.gov (United States)

2010-07-01

...) Excessive shaft bearing temperature. (d) If a centrifugal compressor, fan, or lobe blower handles vapor in... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Vapor compressors and blowers....826 Vapor compressors and blowers. (a) Each inlet and outlet to a compressor or blower which handles...

Numerical simulation of radial compressor stage

Science.gov (United States)

Syka, T.; Luňáček, O.

2013-04-01

Article describes numerical simulations of air flow in radial compressor stage in NUMECA CFD software. In simulations geometry variants with and without seals are used. During tasks evaluating was observed seals influence on flow field and performance parameters of compressor stage. Also is described CFDresults comparison with results from design software based on experimental measurements and monitoring of influence of seals construction on compressor stage efficiency.

Numerical simulation of radial compressor stage

OpenAIRE

Luňáček O.; Syka T.

2013-01-01

Article describes numerical simulations of air flow in radial compressor stage in NUMECA CFD software. In simulations geometry variants with and without seals are used. During tasks evaluating was observed seals influence on flow field and performance parameters of compressor stage. Also is described CFDresults comparison with results from design software based on experimental measurements and monitoring of influence of seals construction on compressor stage efficiency.

U-8 wt %Mo and 7 wt %Mo alloys powder obtained by an hydride-de hydride process

International Nuclear Information System (INIS)

Balart, Silvia N.; Bruzzoni, Pablo; Granovsky, Marta S.; Gribaudo, Luis M. J.; Hermida, Jorge D.; Ovejero, Jose; Rubiolo, Gerardo H.; Vicente, Eduardo E.

2000-01-01

Uranium-molybdenum alloys are been tested as a component in high-density LEU dispersion fuels with very good performances. These alloys need to be transformed to powder due to the manufacturing requirements of the fuels. One method to convert ductile alloys into powder is the hydride-de hydride process, which takes advantage of the ability of the U-α phase to transform to UH 3 : a brittle and relatively low-density compound. U-Mo alloys around 7 and 8 wt % Mo were melted and heat treated at different temperature ranges in order to partially convert γ -phase to α -phase. Subsequent hydriding transforms this α -phase to UH 3 . The volume change associated to the hydride formation embrittled the material which ends up in a powdered alloy. Results of the optical metallography, scanning electron microscopy, X-ray diffraction during different steps of the process are shown. (author)

Insight into destabilization mechanism of Mg-based hydrides interstitially co-doped with nonmetals: a DFT study

Science.gov (United States)

Wu, Zhen; Zhu, Luying; Yang, Fusheng; Zhang, Zaoxiao; Nyamsi, Serge N.

2018-04-01

Mg-based metal hydride is one of the most promising materials for hydrogen energy storage. However, the high thermal stability due to strong bonding effects between the atoms limits its practical application. In order to reduce the thermal stability, a method of doping double nonmetals into Mg-based system was proposed in this study. The density functional theory (DFT) calculation results showed that the thermal stabilities of both the B-N co-doped Mg-based alloy and its hydride are reduced compared with pure Mg-based system. The relative formation enthalpies of the alloy and its hydride are 0.323 and 0.595 eV atom-1, respectively. The values are much higher than those for either singly B- or N-doped Mg-based system. The more significant destabilization by doping double nonmetal elements than single element is mainly attributed to a dual effect in weakening Mg-Ni/NiH4 bonds, caused by criss-cross interactions between B-Ni and N-Mg bonds.

Transient analysis of a variable speed rotary compressor

International Nuclear Information System (INIS)

Park, Youn Cheol

2010-01-01

A transient simulation model of a rolling piston type rotary compressor is developed to predict the dynamic characteristics of a variable speed compressor. The model is based on the principles of conservation, real gas equations, kinematics of the crankshaft and roller, mass flow loss due to leakage, and heat transfer. For the computer simulation of the compressor, the experimental data were obtained from motor performance tests at various operating frequencies. Using the developed model, re-expansion loss, friction loss, mass flow loss and heat transfer loss is estimated as a function of the crankshaft speed in a variable speed compressor. In addition, the compressor efficiency and energy losses are predicted at various compressor-operating frequencies. Since the transient state of the compressor strongly depends on the system, the developed model is combined with a transient system simulation program to get transient variations of the compression process in the system. Motor efficiency, mechanical efficiency, motor torque and volumetric efficiency are calculated with respect to variation of the driving frequency in a rotary compressor.

Cooled-Spool Piston Compressor

Science.gov (United States)

Morris, Brian G.

1994-01-01

Proposed cooled-spool piston compressor driven by hydraulic power and features internal cooling of piston by flowing hydraulic fluid to limit temperature of compressed gas. Provides sufficient cooling for higher compression ratios or reactive gases. Unlike conventional piston compressors, all parts of compressed gas lie at all times within relatively short distance of cooled surface so that gas cooled more effectively.

Reactions of zinc hydride and magnesium hydride with pyridine; synthesis and characterization of 1,4-dihydro-1-pyridylzinc and -magnesium complexes

NARCIS (Netherlands)

Koning, A.J. de; Boersma, J.; Kerk, G.J.M. van der

1980-01-01

The synthesis and characterization of 1,4-dihydro-1-pyridylzinc and -magnesium complexes are described. Zinc hydride and magnesium hydride dissolve in and react with pyridine, and the reaction has been studied in detail in the case of zinc hydride. Evaporation of the solvent after 1–2 hours at 0°C

Crystal structure solution of hydrides containing natEu from neutron powder diffraction data

International Nuclear Information System (INIS)

Kohlmann, H.

1999-01-01

Complete text of publication follows. The location of hydrogen in crystal structures of metal hydrides usually requires neutron diffraction data. Some elements, however, show excessively high absorption cross sections, σ a , for neutrons, thus making this technique seemingly impractical. Therefore no complete, refined crystal structure data of europium hydrides (σ a ( nat Eu) = .4530 barns at λ = 179.8 pm [1]) have been reported so far. It is shown that the absorption can be reduced to a value reasonable for neutron diffraction experiments by taking advantage of the wavelength dependence of σ a combined with the use of annular samples at advanced diffractometers. Neutron powder diffraction data on several nat Eu containing deuterides suitable for the ab initio crystal structure solution and refinement have been taken at D20 and D4 (ILL, Grenoble). The crystal chemistry of these europium hydrides, among them the two new compounds EuMg 2 H 6 and EuMgH 4 [2], is discussed. (author) [1] V.F. Sears, Neutron News 1992, 3, 26-37.; [2] H. Kohlmann, F. Gingl, T. Hansen, K. Yvon, Angew. Chem. Int. Ed. Eng. 1999, 38, accepted

Analysis of Ni-HYDRIDE Thin Film after Surface Plasmon Generation by Laser Technique

Science.gov (United States)

Violante, V.; Castagna, E.; Sibilia, C.; Paoloni, S.; Sarto, F.

2005-12-01

A nickel hydride thin film was studied by the attenuated total reflection method. The differences in behavior between a "black" film, and a pure nickel film "blank," are shown. The black nickel hydride film has been obtained by a short electrolysis with 1 M Li2SO4 electrolyte in light water, A shift in the minimum of the observed reflected light occurs, together with a change in the minimum shape (i.e. its half-height width increases). These two phenomenon are due to the change in the electronic band structure of the metal induced by electrons added to the lattice by hydrogen. The change of the electronic structure, revealed by the laser coupling conditions, leads us to consider that a hydride phase was created. Both the blank (not hydrogenated) and black (hydrogenated) specimens were taken under He-Ne laser beam at the reflectance minimum angle for about three hours. A SIMS analysis was also implemented to reveal differences in the isotopic composition of Cu, as marker element between the blank and black films, in order to study the coupled effect of electrolysis and plasmon-polariton excitation on LENR processes in condensed matter.

Hydride Olefin complexes of tantalum and niobium

NARCIS (Netherlands)

Klazinga, Aan Hendrik

1979-01-01

This thesis describes investigations on low-valent tantalum and niobium hydride and alkyl complexes, particularly the dicyclopentadienyl tantalum hydride olefin complexes Cp2Ta(H)L (L=olefin). ... Zie: Summary

Configuration and testing of a saturated vapor helium compressor

International Nuclear Information System (INIS)

Ludwigsen, J.L.; Iwasa, Y.; Smith, J.L.

1986-01-01

A saturated vapor helium compressor was designed and tested as a component of a helium-temperature refrigeration cycle. The use of the cold compressor allows reduction of both the precooling heat exchanger area and main compressor size compared to a conventional cycle due to increased pressure of the return gas. The compressor tested was a single-piston reciprocating device which was controlled with programmable hydraulic/pneumatic logic. The compressor was mounted at the cold end of a CTI Model 1400 helium liquefier. An average compression ratio of 2.4 was obtained and an average efficiency of 82% was achieved. In computing compressor efficiency, external heat leaks to the compressor were neglected

High-pressure phase transition of alkali metal-transition metal deuteride Li2PdD2

Science.gov (United States)

Yao, Yansun; Stavrou, Elissaios; Goncharov, Alexander F.; Majumdar, Arnab; Wang, Hui; Prakapenka, Vitali B.; Epshteyn, Albert; Purdy, Andrew P.

2017-06-01

A combined theoretical and experimental study of lithium palladium deuteride (Li2PdD2) subjected to pressures up to 50 GPa reveals one structural phase transition near 10 GPa, detected by synchrotron powder x-ray diffraction, and metadynamics simulations. The ambient-pressure tetragonal phase of Li2PdD2 transforms into a monoclinic C2/m phase that is distinct from all known structures of alkali metal-transition metal hydrides/deuterides. The structure of the high-pressure phase was characterized using ab initio computational techniques and from refinement of the powder x-ray diffraction data. In the high-pressure phase, the PdD2 complexes lose molecular integrity and are fused to extended [PdD2]∞ chains. The discovered phase transition and new structure are relevant to the possible hydrogen storage application of Li2PdD2 and alkali metal-transition metal hydrides in general.

Dense-plasma research using ballistic compressors

International Nuclear Information System (INIS)

Hess, H.

1986-01-01

An introduction is given to research on dense (or nonideal) plasmas which can be generated to advantage by ballistic compressors. Some properties of ballistic compressors are discussed especially in comparison with shock tubes. A short review is given on the history of these devices for high-pressure plasma generation. The present state of the art is reported including research on the two ZIE (Central Institute for Electron Physics) ballistic compressors. (author)

Numerical simulation of radial compressor stage

Directory of Open Access Journals (Sweden)

Luňáček O.

2013-04-01

Full Text Available Article describes numerical simulations of air flow in radial compressor stage in NUMECA CFD software. In simulations geometry variants with and without seals are used. During tasks evaluating was observed seals influence on flow field and performance parameters of compressor stage. Also is described CFDresults comparison with results from design software based on experimental measurements and monitoring of influence of seals construction on compressor stage efficiency.

Isotope exchange between gaseous hydrogen and uranium hydride powder

International Nuclear Information System (INIS)

Shugard, Andrew D.; Buffleben, George M.; Johnson, Terry A.; Robinson, David B.

2014-01-01

Highlights: • Isotope exchange between hydrogen gas and uranium hydride powder can be rapid and reversible. • Gas–solid exchange rate is controlled by transport within ∼0.7 μm hydride particles. • Gas chromatographic separation of hydrogen isotopes using uranium hydride is feasible. - Abstract: Isotope exchange between gaseous hydrogen and solid uranium hydride has been studied by flowing hydrogen (deuterium) gas through packed powder beds of uranium deuteride (hydride). We used a residual gas analyzer system to perform real-time analysis of the effluent gas composition. We also developed an exchange and transport model and, by fitting it to the experimental data, extracted kinetic parameters for the isotope exchange reaction. Our results suggest that, from approximately 70 to 700 kPa and 25 to 400 °C, the gas-to-solid exchange rate is controlled by hydrogen and deuterium transport within the ∼0.7 μm diameter uranium hydride particles. We use our kinetic parameters to show that gas chromatographic separation of hydrogen and deuterium using uranium hydride could be feasible

The effect of stress state on zirconium hydride reorientation

Science.gov (United States)

Cinbiz, Mahmut Nedim

Prior to storage in a dry-cask facility, spent nuclear fuel must undergo a vacuum drying cycle during which the spent fuel rods are heated up to elevated temperatures of ≤ 400°C to remove moisture the canisters within the cask. As temperature increases during heating, some of the hydride particles within the cladding dissolve while the internal gas pressure in fuel rods increases generating multi-axial hoop and axial stresses in the closed-end thin-walled cladding tubes. As cool-down starts, the hydrogen in solid solution precipitates as hydride platelets, and if the multiaxial stresses are sufficiently large, the precipitating hydrides reorient from their initial circumferential orientation to radial orientation. Radial hydrides can severely embrittle the spent nuclear fuel cladding at low temperature in response to hoop stress loading. Because the cladding can experience a range of stress states during the thermo-mechanical treatment induced during vacuum drying, this study has investigated the effect of stress state on the process of hydride reorientation during controlled thermo-mechanical treatments utilizing the combination of in situ X-ray diffraction and novel mechanical testing analyzed by the combination of metallography and finite element analysis. The study used cold worked and stress relieved Zircaloy-4 sheet containing approx. 180 wt. ppm hydrogen as its material basis. The failure behavior of this material containing radial hydrides was also studied over a range of temperatures. Finally, samples from reactor-irradiated cladding tubes were examined by X-ray diffraction using synchrotron radiation. To reveal the stress state effect on hydride reorientation, the critical threshold stress to reorient hydrides was determined by designing novel mechanical test samples which produce a range of stress states from uniaxial to "near-equibiaxial" tension when a load is applied. The threshold stress was determined after thermo-mechanical treatments by

Hydrogen Mobility in Disordered Metals Studied by $\\mu$SR

CERN Multimedia

2002-01-01

A few studies of the behaviour of positive muons in metal hydrides have been made during the last three years under the code SC76, although this code is intended primarily for ``diffusion and trapping of positive muons`` in pure or very weakly doped metals. It has been shown in these studies that $\\mu$SR can provide important information even in concentrated hydrides like $ NbH _{,} _{0},7 - _{0} _{,} _{9} $ and $ Zr V _{2} H _{2} _{m}inus _{3} $ especially concerning mutual $\\mu

Studies on displacement behavior between hydrogen and deuterium in hydride column

International Nuclear Information System (INIS)

Lu Guangda; Li Gan; Jiang Guoqiang

2001-01-01

A series displacement experiments between hydrogen and deuterium in ZrCo, LaNi 5 , LaNi 4.7 Al 0.3 and Pd hydride column had been conducted at room temperature about. Results indicate that displacement characteristics related to factors such as temperature, gas flow rate, ratio surface area of solid phase and hydrogen isotope separation factor of the metal-hydrogen system. The palladium hydride have the best displacement characteristics, and LaNi 5 , LaNi 4.7 Al 0.3 and ZrCo are in the next places. Theoretical study reveals that the rule of the exchange reaction of hydrogen isotopes in gas-solid interface determines the displacement behavior and the displacing efficiency depends on exchange rate. The ideal stage mode could be used to describe the displacement breakthrough curve. The height equivalent to theoretical place (HETP) indicates the displacing effects. Also, the separation factor has a serious influence to HETP under the same condition

Preparation of beryllium hydride

International Nuclear Information System (INIS)

Lowrance, B.R.

1975-01-01

A process is described for the preparation of beryllium hydride which comprises pyrolyzing, while in solution in a solvent inert under the reaction conditions, with respect to reactants and products and at a temperature in the range of about 100 0 to about 200 0 C, sufficient to result in the formation of beryllium hydride, a di-t-alkyl beryllium etherate wherein each tertiary alkyl radical contains from 4 to 20 carbon atoms. The pyrolysis is carried out under an atmosphere inert under the reaction conditions, with respect to reactants and products. (U.S.)

Hydrogen adsorption on palladium and palladium hydride at 1 bar

DEFF Research Database (Denmark)

Johansson, Martin; Skulason, Egill; Nielsen, Gunver

2010-01-01

strongly to Pd hydride than to Pd. The activation barrier for desorption at a H coverage of one mono layer is slightly lower on Pd hydride, whereas the activation energy for adsorption is similar on Pd and Pd hydride. It is concluded that the higher sticking probability on Pd hydride is most likely caused...

Hydride observations using the neutrography technique

International Nuclear Information System (INIS)

Meyer, G.; Baruj, A.; Borzone, E.M.; Cardenas, R.; Szames, E.; Somoza, J.; Rivas, S.; Sanchez, F.A.; Marin, J.

2012-01-01

Neutron radiography observations were performed at the RA-6 experimental nuclear facility in Bariloche. Images from a prototype of a hydride-based hydrogen storage device have been obtained. The technique allows visualizing the inner hydride space distribution. The hydride appeared compacted at the lower part of the prototype after several cycles of hydrogen charge and discharge. The technique has also been applied to the study of Zr/ZrH 2 samples. There is a linear relation between the sample width/hydrogen concentration and the photograph grey scale. This information could be useful for the study of nuclear engineering materials and to determine their possible degradation by hydrogen pick up (author)

Hydride heat pump with heat regenerator

Science.gov (United States)

Jones, Jack A. (Inventor)

1991-01-01

A regenerative hydride heat pump process and system is provided which can regenerate a high percentage of the sensible heat of the system. A series of at least four canisters containing a lower temperature performing hydride and a series of at least four canisters containing a higher temperature performing hydride is provided. Each canister contains a heat conductive passageway through which a heat transfer fluid is circulated so that sensible heat is regenerated. The process and system are useful for air conditioning rooms, providing room heat in the winter or for hot water heating throughout the year, and, in general, for pumping heat from a lower temperature to a higher temperature.

Economics of water injected air screw compressor systems

Science.gov (United States)

Venu Madhav, K.; Kovačević, A.

2015-08-01

There is a growing need for compressed air free of entrained oil to be used in industry. In many cases it can be supplied by oil flooded screw compressors with multi stage filtration systems, or by oil free screw compressors. However, if water injected screw compressors can be made to operate reliably, they could be more efficient and therefore cheaper to operate. Unfortunately, to date, such machines have proved to be insufficiently reliable and not cost effective. This paper describes an investigation carried out to determine the current limitations of water injected screw compressor systems and how these could be overcome in the 15-315 kW power range and delivery pressures of 6-10 bar. Modern rotor profiles and approach to sealing and cooling allow reasonably inexpensive air end design. The prototype of the water injected screw compressor air system was built and tested for performance and reliability. The water injected compressor system was compared with the oil injected and oil free compressor systems of the equivalent size including the economic analysis based on the lifecycle costs. Based on the obtained results, it was concluded that water injected screw compressor systems could be designed to deliver clean air free of oil contamination with a better user value proposition than the oil injected or oil free screw compressor systems over the considered range of operations.

30 CFR 75.344 - Compressors.

Science.gov (United States)

2010-07-01

... Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Ventilation § 75.344 Compressors. (a) Except compressors that are...), shall be equipped with a heat activated fire suppression system meeting the requirements of 75.1107-3...

Reaction titration: a convenient method for titering reactive hydride agents (Red-Al, LiAlH4, DIBALH, L-Selectride, NaH, and KH) by No-D NMR spectroscopy.

Science.gov (United States)

Hoye, Thomas R; Aspaas, Andrew W; Eklov, Brian M; Ryba, Troy D

2005-05-26

The concentration of reactive metal hydride (Met-H) reducing agents can be determined (in < or = 20 min) using No-D NMR spectroscopy. The method involves (i) reacting Met-H with an excess of p-methoxybenzaldehyde, (ii) quenching with excess acetic acid, (iii) recording the No-D NMR spectrum of this homogeneous mixture, and (iv) deducing the concentration of Met-H from the % conversion (as measured by integration). By a conceptually related method, the titer of the basic alkali metal hydrides KH and NaH can also be determined.

Harmattan gas plant compressor conversion

Energy Technology Data Exchange (ETDEWEB)

Temple, K. [Altagas Ltd., Calgary, AB (Canada)

2009-07-01

The Harmattan Gas Plant located near the town of Didsbury, Alberta has typical processing units such as amine treating, sulfur recovery, refrigeration, and dehydration. In 1999, a deep cut turbo expander train was added for the extraction of ethane and in 2003 a spec carbon dioxide unit was added. Since its construction in 1961, the plant has undergone many modifications. As such, the plant is a mix of new and old equipment. A 3500 kW Solar Centaur 50LS gas turbine compressor with waste heat recovery was installed at the plant in 2008. This paper reviewed the project from concept to execution and demonstrated how reciprocating compressors were economically replaced with a gas turbine. Altagas had an incentive to invest in the project to lower operating and maintenance costs. Altagas was able to economically replace aging reciprocating compressors with a single turbine driving a centrifugal compressor without any producer subsidies or contract revisions. 2 tabs., 5 figs.

Combined cold compressor/ejector helium refrigerator cycle

International Nuclear Information System (INIS)

Schlafke, A.P.; Brown, D.P.; Wu, K.C.

1984-01-01

This chapter demonstrates how the use of a cold compressor in series with an ejector is an effective way to produce the desired low pressure in a helium refrigeration system. The cold compressor is tentatively located at the low pressure side below the J-T heat exchanger. The ejector is the first stage and the cold compressor is the second stage of the two-stage pumping system. A centrifugal, oil-bearing type compressor was installed on the R and D refrigerator at the Brookhaven National Laboratory. It is determined that the combined cold compressor and ejector system produces a lower temperature on the same load or more cooling at the same temperature compared with a system which uses an ejector alone. Results of the test showed a gain of 20%

High pressure hydriding of sponge-Zr in steam-hydrogen mixtures

International Nuclear Information System (INIS)

Kim, Y.S.

1997-01-01

Hydriding kinetics of thin sponge-Zr layers metallurgically bonded to a Zircaloy disk has been studied by thermogravimetry in the temperature range 350-400 C in 7 MPa hydrogen-steam mixtures. Some specimens were prefilmed with a thin oxide layer prior to exposure to the reactant gas; all were coated with a thin layer of gold to avoid premature reaction at edges. Two types of hydriding were observed in prefilmed specimens, viz., a slow hydrogen absorption process that precedes an accelerated (massive) hydriding. At 7 MPa total pressure, the critical ratio of H 2 /H 2 O above which massive hydriding occurs at 400 C is ∝200. The critical H 2 /H 2 O ratio is shifted to ∝2.5 x 10 3 at 350 C. The slow hydriding process occurs only when conditions for hydriding and oxidation are approximately equally favorable. Based on maximum weight gain, the specimen is completely converted to δ-ZrH 2 by massive hydriding in ∝5 h at a hydriding rate of ∝10 -6 mol H/cm 2 s. Incubation times of 10-20 h prior to the onset of massive hydriding increases with prefilm oxide thickness in the range of 0-10 μm. By changing to a steam-enriched gas, massive hydriding that initially started in a steam-starved condition was arrested by re-formation of a protective oxide scale. (orig.)

A study of stress reorientation of hydrides in zircaloy

Energy Technology Data Exchange (ETDEWEB)

Yourong, Jiang; Bangxin, Zhou [Nuclear Power Inst. of China, Chengdu, SC (China)

1994-10-01

Under the conditions of circumferential tensile stress from 70 to 180 MPa for Zircaloy tubes or the tensile stress from 55 to 180 MPa for Zircaloy-4 plates and temperature cycling between 150 and 400 degree C, the effects of stress and the number of temperature cycling on hydride reorientation in Zircaloy-4 tubes and plates and Zircaloy-2 tubes containing about 220 {mu}g/g hydrogen have been investigated. With the increase of stress and/or the number of temperature cycling, the level of hydride reorientation increases. When hydride reorientation takes place, there is a threshold stress concerned with the number of temperature cycling. Below the threshold stress, hydride reorientation is not obvious. When applied stress is higher than the threshold stress, the level of hydride reorientation increases with the increase of stress and the number of temperature cycling. Hydride reorientation in Zircaloy-4 tubes develops gradually from the outer surface to inner surface. It might be related to the difference of texture between outer surface and inner surface. The threshold stress is affected by both the texture and the value of B. So controlling texture could still restrict hydride reorientation under tensile stress.

Hydrogen absorbing alloy electrode for metal-hydride alkali storage battery and hydrogen absorbing particles for metal-hydride alkali storage battery; Kinzoku-suisokabutsu arukari chikudenchiyo no suiso kyuzo gokin denkyoku oyobi kinzoku-suisokabutsu arukari chikudenchiyo no suiso kyuzo gokin ryushi

Energy Technology Data Exchange (ETDEWEB)

Niiyama, K.; Konno, Y.; Maeda, R.; Nogami, K.; Nishio, K.; Saito, T.

1996-02-02

For preventing degradation due to oxidation of hydrogen absorbing alloy to elongate the life of batteries, a proposal has been made to coat the surface of hydrogen absorbing alloy with electroless nickel plated film. When the surfaces of hydrogen absorbing alloy particles are coated with such electroless nickel plated films having low phosphoric acid content, however, absorption of the oxygen gas produced by overcharge delays to increase the pressure inside the battery because the plated film is unporous dense coat with high crystallinity. This invention relates to phosphoric acid containment in the ratios from 11 to 14wt% in the electroless nickel plated layer of the hydrogen absorbing alloy electrode for the metal-hydride alkali storage battery. Long time is required for the initial activation when the phosphoric acid content is less than 11wt% because the crystallinity of the plated film is too high and forms a dense unporous film. On the other hand, the plated film becomes brittle and tends to peel off from the hydrogen absorbing alloy if phosphoric acid content exceeds 14wt%. 3 figs., 2 tabs.

Orbiting compressor for residential air-conditioners

Energy Technology Data Exchange (ETDEWEB)

Kim, Hyun Jin; Kim, Woo Young; Ahn, Jong Min [Department of Mechanical Engineering, University of Incheon, 12-1 Songdo-dong, Yeonsu-gu, Incheon 406-840 (Korea)

2010-01-15

A new type of compressor, called an orbiting compressor, is introduced in this paper. The orbiting compressor is characterized by an orbiting piston, and the piston or orbiter consists of a circular base plate and a ring type vane protruding vertically from the base plate. The orbiter is made to orbit in an annular space formed between two concentric circular walls via an Oldham-ring mechanism, producing two sealed gas pockets on both sides of the vane wrap with a 180 phase difference. This operating mechanism leads to alternating compression and discharge processes, which results in low torque variation. The orbiting compressor has been designed for an R410A residential air conditioner with a cooling capacity of 10.0 kW. The performance of the orbiting compressor model has been analytically investigated, where the volumetric, adiabatic and mechanical efficiencies were calculated to be 94.8%, 90.4% and 93.4%, respectively for the ARI condition. The EER was estimated to be about 10.86 with a motor efficiency of 89%. (author)

Final Report: DE- FC36-05GO15063, Fundamental Studies of Advanced High-Capacity, Reversible Metal Hydrides

Energy Technology Data Exchange (ETDEWEB)

Jensen, Craig [Univ. of Hawaii, Honolulu, HI (United States); McGrady, Sean [Univ. of New Brunswick, Fredericton NB (Canada); Severa, Godwin [Univ. of Hawaii, Honolulu, HI (United States); Eliseo, Jennifer [Univ. of Hawaii, Honolulu, HI (United States); Chong, Marina [Univ. of Hawaii, Honolulu, HI (United States)

2013-05-31

The project was component of the US DOE, Metal Hydride Center of Excellence (MHCoE). The Sandia National Laboratory led center was established to conduct highly collaborative and multi-disciplinary applied R&D to develop new reversible hydrogen storage materials that meet or exceed DOE/FreedomCAR 2010 and 2015 system targets for hydrogen storage materials. Our approach entailed a wide variety of activities ranging from synthesis, characterization, and evaluation of new candidate hydrogen storage materials; screening of catalysts for high capacity materials requiring kinetics enhancement; development of low temperature methods for nano-confinement of hydrides and determining its effects on the kinetics and thermodynamics of hydrides; and development of novel processes for the direct re-hydrogenation of materials. These efforts have resulted in several advancements the development of hydrogen storage materials. We have greatly extended the fundamental knowledge about the highly promising hydrogen storage carrier, alane (AlH₃), by carrying out the first crystal structure determinations and the first determination of the heats of dehydrogenation of β–AlH₃ and γ-AlD₃. A low-temperature homogenous organometallic approach to incorporation of Al and Mg based hydrides into carbon aerogels has been developed that that allows high loadings without degradation of the nano-porous scaffold. Nano-confinement was found to significantly improve the dehydrogenation kinetics but not effect the enthalpy of dehydrogenation. We conceived, characterized, and synthesized a novel class of potential hydrogen storage materials, bimetallic borohydrides. These novel compounds were found to have many favorable properties including release of significant amounts of hydrogen at moderate temperatures (75-190 º C). However, in situ IR studies in tandem with thermal gravimetric analysis have shown that about 0.5 equivalents of diborane are released during the

Solar photovoltaic charging of high voltage nickel metal hydride batteries using DC power conversion

Science.gov (United States)

Kelly, Nelson A.; Gibson, Thomas L.

There are an increasing number of vehicle choices available that utilize batteries and electric motors to reduce tailpipe emissions and increase fuel economy. The eventual production of electricity and hydrogen in a renewable fashion, such as using solar energy, can achieve the long-term vision of having no tailpipe environmental impact, as well as eliminating the dependence of the transportation sector on dwindling supplies of petroleum for its energy. In this report we will demonstrate the solar-powered charging of the high-voltage nickel-metal hydride (NiMH) battery used in the GM 2-mode hybrid system. In previous studies we have used low-voltage solar modules to produce hydrogen via the electrolysis of water and to directly charge lithium-ion battery modules. Our strategy in the present work was to boost low-voltage PV voltage to over 300 V using DC-DC converters in order to charge the high-voltage NiMH battery, and to regulate the battery charging using software to program the electronic control unit supplied with the battery pack. A protocol for high-voltage battery charging was developed, and the solar to battery charging efficiency was measured under a variety of conditions. We believe this is the first time such high-voltage batteries have been charged using solar energy in order to prove the concept of efficient, solar-powered charging for battery-electric vehicles.

Metal Borohydrides synthesized from metal borides and metal hydrides

DEFF Research Database (Denmark)

Sommer, Sanna

2014-01-01

Aarhus C, Denmark email: gallafogh@hotmail.com / sanna-sommer@hotmail.com Magnesium boride, MgB2, ball milled with MH (M = Li, Na, Ca) followed by hydrogenation under high hydrogen pressure, readily forms the corresponding metal borohydrides, M(BH4)x (M = Li, Na, Ca) and MgH2 according to reaction scheme...

Catalitic effect of Co on hydrogen desorption form nanostucturated magnesium hydride

Directory of Open Access Journals (Sweden)

Matović Ljiljana Lj.

2008-01-01

Full Text Available To study the influence of 3d transition metal addition on desorption kinetics of MgH2 ball milling of MgH2-Co blends was performed under Ar. Microstructural and morphological characterization, performed by XRD and SEM, show a huge correlation with thermal stability and hydrogen desorption properties investigated by DSC. A complex desorption behavior is correlated with the dispersion of the metal additive particles on hydride matrix. The activation energy for H2 desorption from MgH2-Co composite was calculated from both non-isothermal and isothermal methods to be 130 kJ/mol which means that mutually diffusion and nucleation and growth of new phase control the dehydration process.

Centrifugal compressor design for electrically assisted boost

International Nuclear Information System (INIS)

Yang, M Y; Martinez-Botas, R F; Zhuge, W L; Qureshi, U; Richards, B

2013-01-01

Electrically assisted boost is a prominent method to solve the issues of transient lag in turbocharger and remains an optimized operation condition for a compressor due to decoupling from turbine. Usually a centrifugal compressor for gasoline engine boosting is operated at high rotational speed which is beyond the ability of an electric motor in market. In this paper a centrifugal compressor with rotational speed as 120k RPM and pressure ratio as 2.0 is specially developed for electrically assisted boost. A centrifugal compressor including the impeller, vaneless diffuser and the volute is designed by meanline method followed by 3D detailed design. Then CFD method is employed to predict as well as analyse the performance of the design compressor. The results show that the pressure ratio and efficiency at design point is 2.07 and 78% specifically

Catalytic Proton Coupled Electron Transfer from Metal Hydrides to Titanocene Amides, Hydrazides and Imides: Determination of Thermodynamic Parameters Relevant to Nitrogen Fixation.

Science.gov (United States)

Pappas, Iraklis; Chirik, Paul J

2016-10-03

The hydrogenolysis of titanium-nitrogen bonds in a series of bis(cyclopentadienyl) titanium amides, hydrazides and imides by proton coupled electron transfer (PCET) is described. Twelve different N-H bond dissociation free energies (BDFEs) among the various nitrogen-containing ligands were measured or calculated, and effects of metal oxidation state and N-ligand substituent were determined. Two metal hydride complexes, (η 5 -C 5 Me 5 )(py-Ph)Rh-H (py-Ph = 2-pyridylphenyl, [Rh]-H) and (η 5 -C 5 R 5 )(CO) 3 Cr-H ([Cr] R -H, R= H, Me) were evaluated for formal H atom transfer reactivity and were selected due to their relatively weak M-H bond strengths yet ability to activate and cleave molecular hydrogen. Despite comparable M-H BDFEs, disparate reactivity between the two compounds was observed and was traced to the vastly different acidities of the M-H bonds and overall redox potentials of the molecules. With [Rh]-H, catalytic syntheses of ammonia, silylamine and N,N-dimethylhydrazine have been accomplished from the corresponding titanium(IV) complex using H 2 as the stoichiometric H atom source. The data presented in this study provides the thermochemical foundation for the synthesis of NH 3 by proton coupled electron transfer at a well-defined transition metal center.

Investigations of intermetallic alloy hydriding mechanisms. Annual progress report, May 1 1979-April 30, 1980

International Nuclear Information System (INIS)

Livesay, B.R.; Larsen, J.W.

1980-05-01

Investigations are being conducted on mechanisms involved with the hydrogen-metal interactions which control the absorption and desorption processes in intermetallic compounds. The status of the following investigations is reported: modeling of hydride formation; microbalance investigations; microstructure investigations; flexure experiments; resistivity experiments; and nuclear backscattering measurements. These investigations concern fundamental hydrogen interaction mechanisms involved in storage alloys

In situ hydride formation in titanium during focused ion milling.

Science.gov (United States)

Ding, Rengen; Jones, Ian P

2011-01-01

It is well known that titanium and its alloys are sensitive to electrolytes and thus hydrides are commonly observed in electropolished foils. In this study, focused ion beam (FIB) milling was used to prepare thin foils of titanium and its alloys for transmission electron microscopy. The results show the following: (i) titanium hydrides were observed in pure titanium, (ii) the preparation of a bulk sample in water or acid solution resulted in the formation of more hydrides and (iii) FIB milling aids the precipitation of hydrides, but there were never any hydrides in Ti64 and Ti5553.

Improving solid-state hydriding and dehydriding properties of the LiBH{sub 4} plus MgH{sub 2} system with the addition of Mn and V dopants

Energy Technology Data Exchange (ETDEWEB)

Crosby, Kyle; Wan, Xuefei; Shaw, Leon L. [Department of Chemical, Materials and Biomolecular Engineering, University of Connecticut, 97 North Eagleville Road, U-3136, Storrs, CT 06269 (United States)

2010-11-01

The hydriding process of the 2LiH + MgB{sub 2} mixture is controlled by outward diffusion of Mg and inward diffusion of Li and H within MgB{sub 2} crystals to form LiBH{sub 4}. This study explores the feasibility of using transition metal dopants, such as Mn and V, to enhance the diffusion rate and thus the hydriding kinetics. It is found that Mn can indeed enhance the hydriding kinetics of the 2LiH + MgB{sub 2} mixture, while V does not. The major factor in enhancing the diffusion rate and thus the hydriding kinetics is related to the dopant's ability to induce the lattice distortion of MgB{sub 2} crystals. This study demonstrates that the kinetics of the diffusion controlled solid-state hydriding process can be improved by doping if the dopant is properly selected. (author)

Economic analysis of hydride fueled BWR

International Nuclear Information System (INIS)

Ganda, F.; Shuffler, C.; Greenspan, E.; Todreas, N.

2009-01-01

The economic implications of designing BWR cores with hydride fuels instead of conventional oxide fuels are analyzed. The economic analysis methodology adopted is based on the lifetime levelized cost of electricity (COE). Bracketing values (1970 and 3010 $/kWe) are used for the overnight construction costs and for the power scaling factors (0.4 and 0.8) that correlate between a change in the capital cost to a change in the power level. It is concluded that a newly constructed BWR reactor could substantially benefit from the use of 10 x 10 hydride fuel bundles instead of 10 x 10 oxide fuel bundles design presently in use. The cost saving would depend on the core pressure drop constraint that can be implemented in newly constructed BWRs - it is between 2% and 3% for a core pressure drop constraint as of the reference BWR, between 9% and 15% for a 50% higher core pressure drop, and between 12% and 21% higher for close to 100% core pressure. The attainable cost reduction was found insensitive to the specific construction cost but strongly dependent on the power scaling factor. The cost advantage of hydride fuelled cores as compared to that of the oxide reference core depends only weakly on the uranium and SWU prices, on the 'per volume base' fabrication cost of hydride fuels, and on the discount rate used. To be economically competitive, the uranium enrichment required for the hydride fuelled core needs to be around 10%.

Fault detection and diagnosis for refrigerator from compressor sensor

Science.gov (United States)

Keres, Stephen L.; Gomes, Alberto Regio; Litch, Andrew D.

2016-12-06

A refrigerator, a sealed refrigerant system, and method are provided where the refrigerator includes at least a refrigerated compartment and a sealed refrigerant system including an evaporator, a compressor, a condenser, a controller, an evaporator fan, and a condenser fan. The method includes monitoring a frequency of the compressor, and identifying a fault condition in the at least one component of the refrigerant sealed system in response to the compressor frequency. The method may further comprise calculating a compressor frequency rate based upon the rate of change of the compressor frequency, wherein a fault in the condenser fan is identified if the compressor frequency rate is positive and exceeds a condenser fan fault threshold rate, and wherein a fault in the evaporator fan is identified if the compressor frequency rate is negative and exceeds an evaporator fan fault threshold rate.

Thermal modelling of a dry revolving vane compressor

Science.gov (United States)

Ooi, K. T.; Aw, K. T.

2017-08-01

The lubricant used in compressors serves to lubricate, to seal the gaps to reduce internal leakage and to a certain extent, to cool. However, a lubricant free compressor is attractive if lubricants become a source of contaminant, or in areas where the compressor needs be placed under any orientation, such as those in military or portable computing. In this paper, a thermal model for a dry revolving vane compressor is presented. This thermal model sets out to predict the steady-state operating temperatures of the compressor components. The lumped thermal conductance method was employed. The results of the components temperature will be presented and discussed. A high potential for overheating is observed at the shaft bearings.

Multidimensional simulations of hydrides during fuel rod lifecycle

International Nuclear Information System (INIS)

Stafford, D.S.

2015-01-01

In light water reactor fuel rods, waterside corrosion of zirconium-alloy cladding introduces hydrogen into the cladding, where it is slightly soluble. When the solubility limit is reached, the hydrogen precipitates into crystals of zirconium hydride which decrease the ductility of the cladding and may lead to cladding failure during dry storage or transportation events. The distribution of the hydride phase and the orientation of the crystals depend on the history of the spatial temperature and stress profiles in the cladding. In this work, we have expanded the existing hydride modeling capability in the BISON fuel performance code with the goal of predicting both global and local effects on the radial, azimuthal and axial distribution of the hydride phase. We compare results from 1D simulations to published experimental data. We demonstrate the new capability by simulating in 2D a fuel rod throughout a lifecycle that includes irradiation, short-term storage in the spent fuel pool, drying, and interim storage in a dry cask. Using the 2D simulations, we present qualitative predictions of the effects of the inter-pellet gap and the drying conditions on the growth of a hydride rim. - Highlights: • We extend BISON fuel performance code to simulate lifecycle of fuel rods. • We model hydrogen evolution in cladding from reactor through dry storage. • We validate 1D simulations of hydrogen evolution against experiments. • We show results of 2D axisymmetric simulations predicting hydride formation. • We show how our model predicts formation of a hydride rim in the cladding.

Pressure field study of the Tevatron cold compressors

International Nuclear Information System (INIS)

Klebaner, A.L.; Martinez, A.; Soyars, W.M.; Theilacker, J.C.; Fermilab

2003-01-01

The Fermilab Tevatron cryogenic system utilizes high-speed centrifugal cold compressors, manufactured by Ishikawajima-Harima Heavy Industries Co. Ltd. (IHI), for high-energy operations [1]. The compressor is designed to pump 60 g/sec of 3.6 K saturated helium vapor at a pressure ratio of 2.8, with an off-design range of 40 to 70 g/sec. Operating speeds are between 40 and 95 krpm, with a speed of 80 krpm at the design point. Different heat loads and magnet quench performance of each of the twenty-four satellite refrigerators dictates different process pressure and flow rates of the cold compressors. Reducing the process flow rate can cause the centrifugal cold compressor to stop pumping and subsequently surge. Tests have been conducted at the Cryogenic Test Facility at Fermilab to map the pressure field and appropriate efficiency of the IHI hydrodynamic cold compressor. The information allows tuning of each of the twenty-four Tevatron satellite refrigerators to avoid cold compressor operation near the surge and choke lines. A new impeller has also been tested. The Tevatron cold compressor pressure field and efficiency data with the new impeller are presented in this paper

Pressure Field Study of the Tevatron Cold Compressors

International Nuclear Information System (INIS)

Klebaner, A.L.; Martinez, A.; Soyars, W.M.; Theilacker, J.C.

2004-01-01

The Fermilab Tevatron cryogenic system utilizes high-speed centrifugal cold compressors, manufactured by Ishikawajima-Harima Heavy Industries Co. Ltd. (IHI), for high-energy operations. The compressor is designed to pump 60 g/sec of 3.6 K saturated helium vapor at a pressure ratio of 2.8, with an off-design range of 40 to 70 g/sec. Operating speeds are between 40,000 and 95,000 rpm, with a speed of 80,000 rpm at the design point. Different heat loads and magnet quench performance of each of the twenty-four satellite refrigerators dictates different process pressure and flow rates of the cold compressors. Reducing the process flow rate can cause the centrifugal cold compressor to stop pumping and subsequently surge. Tests have been conducted at the Cryogenic Test Facility at Fermilab to map the pressure field and appropriate efficiency of the IHI hydrodynamic cold compressor. The information allows tuning of each of the twenty-four Tevatron satellite refrigerators to avoid cold compressor operation near the surge and choke lines. A new impeller has also been tested. The Tevatron cold compressor pressure field and efficiency data with the new impeller are presented in this paper

NASA low speed centrifugal compressor

Science.gov (United States)

Hathaway, Michael D.

1990-01-01

The flow characteristics of a low speed centrifugal compressor were examined at NASA Lewis Research Center to improve understanding of the flow in centrifugal compressors, to provide models of various flow phenomena, and to acquire benchmark data for three dimensional viscous flow code validation. The paper describes the objectives, test facilities' instrumentation, and experiment preliminary comparisons.

Compressor Has No Moving Macroscopic Parts

Science.gov (United States)

Gasser, Max

1995-01-01

Compressor containing no moving macroscopic parts functions by alternating piston and valve actions of successive beds of magnetic particles. Fabricated easily because no need for precisely fitting parts rotating or sliding on each other. Also no need for lubricant fluid contaminating fluid to be compressed. Compressor operates continuously, eliminating troublesome on/off cycling of other compressors, and decreasing consumption of energy. Phased cells push fluid from bottom to top, adding increments of pressure. Each cell contains magnetic powder particles loose when electromagnet coil deenergized, but tightly packed when coil energized.

Creating nanoshell on the surface of titanium hydride bead

Directory of Open Access Journals (Sweden)

PAVLENKO Vyacheslav Ivanovich

2016-12-01

Full Text Available The article presents data on the modification of titanium hydride bead by creating titanium nanoshell on its surface by ion-plasma vacuum magnetron sputtering. To apply titanium nanoshell on the titanium hydride bead vacuum coating plant of multifunctional nanocomposite coatings QVADRA 500 located in the center of high technology was used. Analysis of the micrographs of the original surface of titanium hydride bead showed that the microstructure of the surface is flat, smooth, in addition the analysis of the microstructure of material surface showed the presence of small porosity, roughness, mainly cavities, as well as shallow longitudinal cracks. The presence of oxide film in titanium hydride prevents the free release of hydrogen and fills some micro-cracks on the surface. Differential thermal analysis of both samples was conducted to determine the thermal stability of the initial titanium hydride bead and bead with applied titanium nanoshell. Hydrogen thermal desorption spectra of the samples of the initial titanium hydride bead and bead with applied titanium nanoshell show different thermal stability of compared materials in the temperature range from 550 to 860о C. Titanium nanoshells applied in this way allows increasing the heat resistance of titanium hydride bead – the temperature of starting decomposition is 695о C and temperature when decomposition finishes is more than 1000о C. Modified in this way titanium hydride bead can be used as a filler in the radiation protective materials used in the construction or upgrading biological protection of nuclear power plants.

Comparative assessment of characteristic part-load performances of screw compressors and turbo-compressors; Vergleich der charakteristischen Teillastwirkungsgrade von Schrauben- und Turboverdichtern

Energy Technology Data Exchange (ETDEWEB)

Brasz, J.J.; Hartmann, K. [Carrier Corp., Syracuse, NY (United States)]|[Carrier Corp., Muenchen (Germany)

2006-07-01

The relative part-load performance of screw compressors and radial compressors is compared. Compressor part load is represented by a 2D characteristic field with the pressure on the vertical axis as a function of mass flow on the horizontal axis, with efficiencies given for any possible combination of pressure and mass flow. While this manner of representation is common for radial compressors, it is new for screw compressors. In the comparison of compression efficiencies, the focus is on vapour compression. For a valid comparative assessment of total compression, also the mechanical and/or electric loss through bearings, transmission, drive and (in case of variable-speed drives) frequency converters must be taken into account. (orig.)

High H⁻ ionic conductivity in barium hydride.

Science.gov (United States)

Verbraeken, Maarten C; Cheung, Chaksum; Suard, Emmanuelle; Irvine, John T S

2015-01-01

With hydrogen being seen as a key renewable energy vector, the search for materials exhibiting fast hydrogen transport becomes ever more important. Not only do hydrogen storage materials require high mobility of hydrogen in the solid state, but the efficiency of electrochemical devices is also largely determined by fast ionic transport. Although the heavy alkaline-earth hydrides are of limited interest for their hydrogen storage potential, owing to low gravimetric densities, their ionic nature may prove useful in new electrochemical applications, especially as an ionically conducting electrolyte material. Here we show that barium hydride shows fast pure ionic transport of hydride ions (H(-)) in the high-temperature, high-symmetry phase. Although some conductivity studies have been reported on related materials previously, the nature of the charge carriers has not been determined. BaH2 gives rise to hydride ion conductivity of 0.2 S cm(-1) at 630 °C. This is an order of magnitude larger than that of state-of-the-art proton-conducting perovskites or oxide ion conductors at this temperature. These results suggest that the alkaline-earth hydrides form an important new family of materials, with potential use in a number of applications, such as separation membranes, electrochemical reactors and so on.

Precipitation of γ-zirconium hydride in zirconium

International Nuclear Information System (INIS)

Carpenter, G.J.C.

1978-01-01

A mechanism for the precipitation of γ-zirconium hydride in zirconium is presented which does not require the diffusion of zirconium. The transformation is completed by shears caused by 1/3 (10 anti 10) Shockley partial dislocations on alternate zirconium basal planes, either by homogeneous nucleation or at lattice imperfections. Homogeneous nucleation is considered least likely in view of the large nucleation barrier involved. Hydrides may form at dislocations by the generation of partials by means of either a pole or ratchet mechanism. The former requires dislocations with a component of Burgers vector along the c-axis, but contrast experiments show that these are not normally observed in annealed zirconium. It is therefore most likely that intragranular hydrides form at the regular 1/3 (11 anti 20) dislocations, possibly by means of a ratchet mechanism. Contrast experiments in the electron microscope show that the precipitates have a shear character consistent with the mechanism suggested. The possibility that the shear dislocations associated with the hydrides are emissary dislocations is considered and a model suggested in which this function is satisfied together with the partial relief of misfit stresses. The large shear strains associated with the precipitation mechanism may play an important role in the preferential orientation of hydrides under stress

Understanding hydride formation in Zr-1Nb alloy through microstructural characterization

International Nuclear Information System (INIS)

Neogy, S.; Srivastava, D.; Tewari, R.; Singh, R.N.; Dey, G.K.; De, P.K.; Banerjee, S.

2003-07-01

In this study the experimental results of hydride formation and their microstructure evolution in Zr-1Nb alloy is presented. This Zr-1Nb binary alloy and other Zr-1 Nb based ternary and quaternary alloys are being used as fuel tube materials and have the potential for meeting the requirement of high burn up fuel. Hydriding of Zr-1Nb alloy having a microstructure comprising equiaxed α grains and a uniform distribution of spherical particles of the β phase has been carried out in this study. The specimens have been hydrided by gaseous charging method to different hydrogen levels. The microstructures of hydrided samples were examined as a function of hydrogen content. The formation of δ hydride in slow cooled specimens and formation of γ hydride in rapidly cooled specimens has been studied with their morphology, habit plane and orientation relationship with the α matrix in view. The habit planes of either type of hydride phase has been determined and compared with those observed in other Zr-Nb alloys. The orientation relationship between the α matrix and the δ hydride was found to be the following: (0001) α // (111) δ and [1120] α // [110] δ . The orientation relationship between the α matrix and the γ hydride was of the following type: (0001) α // (111) γ and [1120] α // [110] γ . The internal structure of both types of hydride has been examined. The effect of the presence of the spherical β phase particles in the a matrix on the growth of the hydride plates has been investigated. (author)

Development of zirconium hydride highly effective moderator materials

International Nuclear Information System (INIS)

Yin Changgeng

2005-10-01

The zirconium hydride with highly content of hydrogen and low density is new efficient moderator material for space nuclear power reactor. Russia has researched it to use as new highly moderator and radiation protection materials. Japanese has located it between the top of pressure vessel and the main protection as a shelter, the work temperature is rach to 220 degree C. The zirconium hydride moderator blocks are main parts of space nuclear power reactor. Development of zirconium hydride moderator materials have strength research and apply value. Nuclear Power Research and Design Instituteoh China (NPIC) has sep up the hydrogenation device and inspect systems, and accumurate a large of experience about zirconium hydride, also set up a strict system of QA and QC. (authors)

Impact of inlet coherent motions on compressor performance

Science.gov (United States)

Forlese, Jacopo; Spoleti, Giovanni

2017-08-01

Automotive engine induction systems may be characterized by significant flow angularity and total pressure distortion at the compressor inlet. The impact of the swirl on compressor performance should be quantified to guide the design of the induction systems. In diesel engines, the presence of a valve for flow reduction and control of low pressure EGR recirculation could generate coherent motion and influence the performance of the compressor. Starting from experimental map, the compressor speed-lines have been simulated using a 3D CFD commercial code imposing different concept motion at the inlet. The swirl intensity, the direction and the number of vortices have been imposed in order to taking into account some combinations. Finally, a merit function has been defined to evaluate the performance of the compressor with the defined swirl concepts. The aim of the current work is to obtain an indication on the effect of a swirling motion at the compressor inlet on the engine performance and provide a guideline to the induction system design.

49 CFR 178.337-15 - Pumps and compressors.

Science.gov (United States)

2010-10-01

... 49 Transportation 2 2010-10-01 2010-10-01 false Pumps and compressors. 178.337-15 Section 178.337... PACKAGINGS Specifications for Containers for Motor Vehicle Transportation § 178.337-15 Pumps and compressors. (a) Liquid pumps or gas compressors, if used, must be of suitable design, adequately protected...

49 CFR 178.338-17 - Pumps and compressors.

Science.gov (United States)

2010-10-01

... 49 Transportation 2 2010-10-01 2010-10-01 false Pumps and compressors. 178.338-17 Section 178.338... PACKAGINGS Specifications for Containers for Motor Vehicle Transportation § 178.338-17 Pumps and compressors. (a) Liquid pumps and gas compressors, if used, must be of suitable design, adequately protected...

14 CFR 33.27 - Turbine, compressor, fan, and turbosupercharger rotors.

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Turbine, compressor, fan, and... Turbine, compressor, fan, and turbosupercharger rotors. (a) Turbine, compressor, fan, and... affect turbine, compressor, fan, and turbosupercharger rotor structural integrity will not be exceeded in...

Theoretical study of a novel refrigeration compressor - Part II: Performance of a rotating discharge valve in the revolving vane (RV) compressor

Energy Technology Data Exchange (ETDEWEB)

Teh, Y.L.; Ooi, K.T. [Thermal and Fluids Engineering Division, School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Avenue, S639798 (Singapore); Djamari, D. Wibowo [Engineering Mechanics Division, School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Avenue, S639798 (Singapore)

2009-08-15

A new refrigeration compressor, named 'Revolving Vane (RV) compressor', has been introduced in Part I of this paper series. For a first time in refrigeration compressors, a rotating discharge valve is employed in the RV compressor mainly due to the rotation of the entire cylinder. This paper presents a theoretical investigation on the dynamic behavior of a reed-type discharge valve undergoing rotatory motion, with the primary objective of elucidating the applicability of such valves in refrigeration compressors. Under the application of the Euler-Bernoulli beam theory, a mathematical model of the rotating valve is formulated and the transient response of the valve under centrifugal loads in addition to pressure forces is analyzed. Results have shown that under careful design considerations, the performance as well as the reliability of the rotating discharge valve can be enhanced as compared to a non-rotating valve that has been used in all refrigeration compressors currently. (author)

High Efficiency Centrifugal Compressor for Rotorcraft Applications

Science.gov (United States)

Medic, Gorazd; Sharma, Om P.; Jongwook, Joo; Hardin, Larry W.; McCormick, Duane C.; Cousins, William T.; Lurie, Elizabeth A.; Shabbir, Aamir; Holley, Brian M.; Van Slooten, Paul R.

2017-01-01

A centrifugal compressor research effort conducted by United Technologies Research Center under NASA Research Announcement NNC08CB03C is documented. The objectives were to identify key technical barriers to advancing the aerodynamic performance of high-efficiency, high work factor, compact centrifugal compressor aft-stages for turboshaft engines; to acquire measurements needed to overcome the technical barriers and inform future designs; to design, fabricate, and test a new research compressor in which to acquire the requisite flow field data. A new High-Efficiency Centrifugal Compressor stage -- splittered impeller, splittered diffuser, 90 degree bend, and exit guide vanes -- with aerodynamically aggressive performance and configuration (compactness) goals were designed, fabricated, and subquently tested at the NASA Glenn Research Center.

Sorption properties of nanocrystalline metal hydrides for the storage of hydrogen; Sorptionseigenschaften von nanokristallinen Metallhydriden fuer die Wasserstoffspeicherung

Energy Technology Data Exchange (ETDEWEB)

Oelerich, W.

2000-07-01

For the utilisation of hydrogen in emission-free automobiles new nanostructured Mg-based metal hydrides were developed. These materials show significantly faster absorption and desorption kinetics, which can be even further enhanced by additions of suitable catalysts. Contrary to conventional magnesium powder, hydrogenation at room temperature is demonstrated for the first time. During dehydrogenation at 250 C a desorption rate of 3 to 8 kW/kg with a capacity of 2.5 kWh/kg is achieved, that fulfills the technical requirements for automobile application. (orig.) [German] Im Hinblick auf den Einsatz von Wasserstoff in emissionsfreien Kraftfahrzeugen wurden neuartige nanostrukturierte Metallhydride auf Basis von Magnesium hergestellt. Diese Materialien zeigen eine deutlich schnellere Absorptions- und Desorptionskinetik, die sich durch den Zusatz von geeigneten Katalysatoren noch weiter steigern laesst. Im Gegensatz zu konventionellem Magnesiumpulver konnte erstmals eine Hydrierung bei Raumtemperatur demonstriert werden. Bei der Dehydrierung bei 250 C wird eine Desorptionsrate von 3 bis 8 kW/kg bei einer Kapazitaet von 2,5 kWh/kg erreicht, die die technischen Leistungsanforderungen von Kraftfahrzeugen erfuellt. (orig.)

Possibility of Thermomechanical Compressor Application in Desalination Plants

Science.gov (United States)

Blagin, E. V.; Shimanov, A. A.; Uglanov, D. A.; Korneev, S. S.

2018-01-01

This article deals with estimation of thermocompressor operating possibility in desalination plant with mechanical vapour compressor. In this plant thermocompressor is used instead of commonly used centrifugal compressor. Preliminary analysis shows that such plant is able to operate, however, power consumption is 3.5-6.5 higher in comparison with traditional MVC plant. In turn, utilization of thermocompressor allows avoiding usual high-frequency drive of centrifugal compressor. Drives with frequency of 50 Hz are enough for thermocompressor when centrifugal compressor requires drives with frequency up to 500 Hz and higher. Approximate thermocompressor dimensions are estimated.

Tritium in metals

International Nuclear Information System (INIS)

Schober, T.

1990-01-01

In this Chapter a review is given of some of the important features of metal tritides as opposed to hydrides and deuterides. After an introduction to the topics of tritium and tritium in metals information will be presented on a variety of metal-tritium systems. Of main interest here are the differences from the classic hydrogen behavior; the so called isotope effect. A second important topic is that of aging effects produced by the accumulation of 3 He in the samples. (orig.)

Design features of fans, blowers, and compressors

Science.gov (United States)

Cheremisinoff, N. P.; Cheremisinoff, P. N.

Fan engineering and compression machines are discussed. Basic aspects of fan performance and design are reviewed, and the design and performance characteristics of radial-flow fans, axial-flow fans, and controllable pitch fans are examined in detail. Air-conditioning systems are discussed, and noise, vibration, and mechanical considerations in fans are extensively examined. The thermodynamic principles governing compression machines are reviewed, and piston compressors, rotary compressors, blowers, and centrifugal compressors are discussed.

Modeling of surge in free-spool centrifugal compressors : experimental validation

NARCIS (Netherlands)

Gravdahl, J.T.; Willems, F.P.T.; Jager, de A.G.; Egeland, O.

2004-01-01

The derivation of a compressor characteristic, and the experimental validation of a dynamic model for a variable speed centrifugal compressor using this characteristic, are presented. The dynamic compressor model of Fink et al. is used, and a variable speed compressor characteristic is derived by

New concept single screw compressors and their manufacture technology

Science.gov (United States)

Feng, Q.; Liu, F.; Chang, L.; Feng, C.; Peng, C.; Xie, J.; van den Broek, M.

2017-08-01

Single screw compressors were generally acknowledged as one of the nearly perfect machines by compressor researchers and manufacturers. However the rapid wear of the star-wheel in a single screw compressor during operation is a key reason why it hasn’t previously joined the main current compressors’ market. After more than ten years of effective work, the authors of this paper have proposed a new concept single screw compressor whose mesh-couple profile is enveloped with multi-column. Also a new design method and manufacture equipment for this kind of compressor have been developed and are described in this paper. A lot of prototype tests and a long period of industrial operations under full loading conditions have shown that the mesh-couple profiles of the new concept single compressors have excellent anti-wearness.

The synthesis and properties of some organometallic compounds containing group IV (Ge, Sn)-group II (Zn, Cd) metal---metal bonds

NARCIS (Netherlands)

Des Tombe, F.J.A.; Kerk, G.J.M. van der; Creemers, H.M.J.C.; Carey, N.A.D.; Noltes, J.G.

1972-01-01

The reactions of triphenylgermane and triphenyltin hydride with coordinatively saturated organozinc or organocadmium compounds give organometallic complexes containing Group IV (Ge, Sn)-Group II(Zn, Cd) metal---metal bonds. The 2,2′-bipyridine complexes show solvent-dependent charge-transfer

Identification of the zirconium hydrides metallography in zircaloy-2

International Nuclear Information System (INIS)

Garcia Gonzalez, F.

1968-01-01

Technique for the Identification of the zirconium hydrides in metallographic specimens have been developed. Microhardness, quantitative estimation and relative orientation of the present hydrides as well as grain size determination of the different Zircaloy-2 tube specimens have also been made. The specimens used were corrosion- tested in water during various periods of time at 300 degree castrating, prior to the metallographic examination. Reference specimens, as received, and heavily hydride specimens in a hydrogen atmosphere at 800 degree centigrees, have been used in the previous stages of the work. No difficulties have been met in this early stage of acquaintanceship with the zirconium hydrides. (Author) 5 refs

Rotary Compressor Noise Analysis Using Mechanisms and Electromagnetics Coupled Approach

OpenAIRE

Chung, Jinah; Lee, Uiyoon; Lee, Jeongbae; Lee, Unseop; Han, Eunsil; Yoon, Jinhwan

2016-01-01

This research is conducted to investigate noise source and design low noise compressors. For improving energy efficiency, the rotary compressor with variable speed brushless DC motor is increasingly adopted for appliances. However brushless DC motor makes more compressor vibration than constant speed motor compressor at high speed operating condition. Therefore it is necessary to reduce noise and vibration for improving air conditioner quality. In this study, compressor’s noise and vibrat...

Internal friction study of hydrides in zirconium at low hydrogen contents

International Nuclear Information System (INIS)

Peretti, H.A.; Corso, H.L.; Gonzalez, O.A.; Fernandez, L.; Ghilarducci, A.A.; Salva, H.R.

1999-01-01

Full text: Internal friction and shear modulus measurements were carried out on crystal bar zirconium in the as received and hydride conditions using an inverted forced pendulum. Hydriding was achieved in two ways: inside and out of the pendulum. The final hydrogen content determined by fusion analysis in the 'in situ' hydride sample was of 36 ppm. Another sample was hydride by the cathodic charge method with 25 ppm. The thermal solid solubility (TSS) phase boundary presents hysteresis between the precipitation (TSSP) and the dissolution (TSSD) temperatures for the zirconium hydrides. During the first thermal cycling the anelastic effects could be attributed to the δ, ε and metastable γ zirconium hydrides. After 'in situ' annealing at 490 K, these peaks completely disappear in the electrolytically charged sample, while in the 'in situ' hydride, the peaks remain with decreasing intensity. This effect can be understood in terms of the different surface conditions of the samples. (author)

A Bimetallic Nickel–Gallium Complex Catalyzes CO ₂ Hydrogenation via the Intermediacy of an Anionic d ¹⁰ Nickel Hydride

Energy Technology Data Exchange (ETDEWEB)

Cammarota, Ryan C. [Department of Chemistry, University of Minnesota, 207 Pleasant Street SE, Minneapolis, Minnesota 55455, United States; Vollmer, Matthew V. [Department of Chemistry, University of Minnesota, 207 Pleasant Street SE, Minneapolis, Minnesota 55455, United States; Xie, Jing [Department of Chemistry, University of Minnesota, 207 Pleasant Street SE, Minneapolis, Minnesota 55455, United States; Supercomputing; Ye, Jingyun [Department of Chemistry, University of Minnesota, 207 Pleasant Street SE, Minneapolis, Minnesota 55455, United States; Supercomputing; Linehan, John C. [Pacific Northwest National Laboratory, P.O. Box 999, MS K2-57, Richland, Washington 99352, United States; Burgess, Samantha A. [Pacific Northwest National Laboratory, P.O. Box 999, MS K2-57, Richland, Washington 99352, United States; Appel, Aaron M. [Pacific Northwest National Laboratory, P.O. Box 999, MS K2-57, Richland, Washington 99352, United States; Gagliardi, Laura [Department of Chemistry, University of Minnesota, 207 Pleasant Street SE, Minneapolis, Minnesota 55455, United States; Supercomputing; Lu, Connie C. [Department of Chemistry, University of Minnesota, 207 Pleasant Street SE, Minneapolis, Minnesota 55455, United States

2017-09-28

Large-scale CO2 hydrogenation could offer a renewable stream of industrially important C1 chemicals while reducing CO2 emissions. Critical to this opportunity is the requirement for inexpensive catalysts based on earth-abundant metals instead of precious metals. We report a nickel-gallium complex featuring a Ni(0)→Ga(III) bond that shows remarkable catalytic activity for hydrogenating CO2 to formate at ambient temperature (3150 turnovers, turnover frequency = 9700 h-1), compared with prior homogeneous Ni-centred catalysts. The Lewis acidic Ga(III) ion plays a pivotal role by stabilizing reactive catalytic intermediates, including a rare anionic d10 Ni hydride. The structure of this reactive intermediate shows a terminal Ni-H, for which the hydride donor strength rivals those of precious metal-hydrides. Collectively, our experimental and computational results demonstrate that modulating a transition metal center via a direct interaction with a Lewis acidic support can be a powerful strategy for promoting new reactivity paradigms in base-metal catalysis. The work was supported as part of the Inorganometallic Catalysis Design Center, an Energy Frontier Research Center funded by the U.S. Department of Energy (DOE), Office of Science, Basic Energy Sciences under Award DE-SC0012702. R.C.C. and M.V.V. were supported by DOE Office of Science Graduate Student Research and National Science Foundation Graduate Research Fellowship programs, respectively. J.C.L., S.A.B., and A.M.A. were supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences & Biosciences. Pacific Northwest National Laboratory is operated by Battelle for the U.S. Department of Energy.

Design of small centrifugal compressor test model for a supercritical CO2 compressor in the fast reactor power plant

International Nuclear Information System (INIS)

Muto, Y.; Ishizuka, T.; Aritomi, M.

2008-01-01

In order to clarify the CO 2 compressor performance in the vicinity of critical point, a research project has been started in Tokyo Institute of Technology based on Japanese government fund. This paper describes how fundamental parameters were selected and sizing of a small and high speed impeller of the test centrifugal compressor. The concept of canned type compressor structures provided with high speed electric motor and preliminary aerodynamic performance prediction are also given. (authors)

High frequency dynamics in centrifugal compressors

NARCIS (Netherlands)

Twerda, A.; Meulendijks, D.; Smeulers, J.P.M.; Handel, R. van den; Lier, L.J. van

2008-01-01

Problems with centrifugal compressors relating to high frequency, i.e. Blade passing frequency (BPF) are increasing. Pulsations and vibrations generated in centrifugal compressors can lead to nuisance, due to strong tonal noise, and even breakdown. In several cases the root cause of a failure or a

Turbofan compressor dynamics during afterburner transients

Science.gov (United States)

Kurkov, A. P.

1976-01-01

The effects of afterburner light-off and shut-down transients on the compressor stability are investigated. The reported experimental results are based on detailed high response pressure and temperature measurements on the TF30-P-3 turbofan engine. The tests were performed in an altitude test chamber simulating high altitude engine operation. It is shown that during both types of transients, flow breaks down in the forward part of the fan bypass duct. At a sufficiently low engine inlet pressure this resulted in a compressor stall. Complete flow breakdown within the compressor was preceded by a rotating stall. At some locations in the compressor, rotating stall cells initially extended only through part of the blade span. For the shutdown transient the time between first and last detected occurrence of rotating stall is related to the flow Reynolds number. An attempt was made to deduce the number and speed of propagation of rotating stall cells.

Boron hydride analogues of the fullerenes

International Nuclear Information System (INIS)

Quong, A.A.; Pederson, M.R.; Broughton, J.Q.

1994-01-01

The BH moiety is isoelectronic with C. We have studied the stability of the (BH) 60 analogue of the C 60 fullerene as well as the dual-structure (BH) 32 icosahedron, both of them being putative structures, by performing local-density-functional electronic calculations. To aid in our analysis, we have also studied other homologues of these systems. We find that the latter, i.e., the dual structure, is the more stable although the former is as stable as one of the latter's lower homologues. Boron hydrides, it seems, naturally form the dual structures used in algorithmic optimization of complex fullerene systems. Fully relaxed geometries are reported as well as electron affinities and effective Hubbard U parameters. These systems form very stable anions and we conclude that a search for BH analogues of the C 60 alkali-metal supeconductors might prove very fruitful

Equivalent circuit parameters of nickel/metal hydride batteries from sparse impedance measurements

Science.gov (United States)

Nelatury, Sudarshan Rao; Singh, Pritpal

In a recent communication, a method for extracting the equivalent circuit parameters of a lead acid battery from sparse (only three) impedance spectroscopy observations at three different frequencies was proposed. It was based on an equivalent circuit consisting of a bulk resistance, a reaction resistance and a constant phase element (CPE). Such a circuit is a very appropriate model of a lead-acid cell at high state of charge (SOC). This paper is a sequel to it and presents an application of it in case of nickel/metal hydride (Ni/MH) batteries, which also at high SOC are represented by the same circuit configuration. But when the SOC of a Ni/MH battery under interrogation goes low, The EIS curve has a positive slope at the low frequency end and our technique yields complex values for the otherwise real circuit parameters, suggesting the need for additional elements in the equivalent circuit and a definite relationship between parameter consistency and SOC. To improvise the previous algorithm, in order that it works reasonably well at both high and low SOCs, we propose three more measurements—two at very low frequencies to include the Warburg response and one at a high frequency to model the series inductance, in addition to the three in the mid frequency band—totally six measurements. In most of the today's instrumentation, it is the user who should choose the circuit configuration and the number of frequencies where impedance should be measured and the accompanying software performs data fitting by complex nonlinear least squares. The proposed method has built into it an SOC-based decision-making capability—both to choose the circuit configuration and to estimate the values of the circuit elements.

Metal Hydride Nanoparticles with Ultrahigh Structural Stability and Hydrogen Storage Activity Derived from Microencapsulated Nanoconfinement.

Science.gov (United States)

Zhang, Jiguang; Zhu, Yunfeng; Lin, Huaijun; Liu, Yana; Zhang, Yao; Li, Shenyang; Ma, Zhongliang; Li, Liquan

2017-06-01

Metal hydrides (MHs) have recently been designed for hydrogen sensors, switchable mirrors, rechargeable batteries, and other energy-storage and conversion-related applications. The demands of MHs, particular fast hydrogen absorption/desorption kinetics, have brought their sizes to nanoscale. However, the nanostructured MHs generally suffer from surface passivation and low aggregation-resisting structural stability upon absorption/desorption. This study reports a novel strategy named microencapsulated nanoconfinement to realize local synthesis of nano-MHs, which possess ultrahigh structural stability and superior desorption kinetics. Monodispersed Mg 2 NiH 4 single crystal nanoparticles (NPs) are in situ encapsulated on the surface of graphene sheets (GS) through facile gas-solid reactions. This well-defined MgO coating layer with a thickness of ≈3 nm efficiently separates the NPs from each other to prevent aggregation during hydrogen absorption/desorption cycles, leading to excellent thermal and mechanical stability. More interestingly, the MgO layer shows superior gas-selective permeability to prevent further oxidation of Mg 2 NiH 4 meanwhile accessible for hydrogen absorption/desorption. As a result, an extremely low activation energy (31.2 kJ mol -1 ) for the dehydrogenation reaction is achieved. This study provides alternative insights into designing nanosized MHs with both excellent hydrogen storage activity and thermal/mechanical stability exempting surface modification by agents. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Studies on MgNi-Based Metal Hydride Electrode with Aqueous Electrolytes Composed of Various Hydroxides

Directory of Open Access Journals (Sweden)

Jean Nei

2016-08-01

Full Text Available Compositions of MgNi-based amorphous-monocrystalline thin films produced by radio frequency (RF sputtering with a varying composition target have been optimized. The composition Mg52Ni39Co3Mn6 is identified to possess the highest initial discharge capacity of 640 mAh·g−1 with a 50 mA·g−1 discharge current density. Reproduction in bulk form of Mg52Ni39Co3Mn6 alloy composition was prepared through a combination of melt spinning (MS and mechanical alloying (MA, shows a sponge-like microstructure with >95% amorphous content, and is chosen as the metal hydride (MH alloy for a sequence of electrolyte experiments with various hydroxides including LiOH, NaOH, KOH, RbOH, CsOH, and (C2H54N(OH. The electrolyte conductivity is found to be closely related to cation size in the hydroxide compound used as 1 M additive to the 4 M KOH aqueous solution. The degradation performance of Mg52Ni39Co3Mn6 alloy through cycling demonstrates a strong correlation with the redox potential of the cation in the alkali hydroxide compound used as 1 M additive to the 5 M KOH aqueous solution. NaOH, CsOH, and (C2H54N(OH additions are found to achieve a good balance between corrosion and conductivity performances.

Pulse compressor with aberration correction

Energy Technology Data Exchange (ETDEWEB)

Mankos, Marian [Electron Optica, Inc., Palo Alto, CA (United States)

2015-11-30

In this SBIR project, Electron Optica, Inc. (EOI) is developing an electron mirror-based pulse compressor attachment to new and retrofitted dynamic transmission electron microscopes (DTEMs) and ultrafast electron diffraction (UED) cameras for improving the temporal resolution of these instruments from the characteristic range of a few picoseconds to a few nanoseconds and beyond, into the sub-100 femtosecond range. The improvement will enable electron microscopes and diffraction cameras to better resolve the dynamics of reactions in the areas of solid state physics, chemistry, and biology. EOI’s pulse compressor technology utilizes the combination of electron mirror optics and a magnetic beam separator to compress the electron pulse. The design exploits the symmetry inherent in reversing the electron trajectory in the mirror in order to compress the temporally broadened beam. This system also simultaneously corrects the chromatic and spherical aberration of the objective lens for improved spatial resolution. This correction will be found valuable as the source size is reduced with laser-triggered point source emitters. With such emitters, it might be possible to significantly reduce the illuminated area and carry out ultrafast diffraction experiments from small regions of the sample, e.g. from individual grains or nanoparticles. During phase I, EOI drafted a set of candidate pulse compressor architectures and evaluated the trade-offs between temporal resolution and electron bunch size to achieve the optimum design for two particular applications with market potential: increasing the temporal and spatial resolution of UEDs, and increasing the temporal and spatial resolution of DTEMs. Specialized software packages that have been developed by MEBS, Ltd. were used to calculate the electron optical properties of the key pulse compressor components: namely, the magnetic prism, the electron mirror, and the electron lenses. In the final step, these results were folded

Rotating stall simulation for axial and centrifugal compressors

Science.gov (United States)

Halawa, Taher; Gadala, Mohamed S.

2017-05-01

This study presents a numerical simulation of the rotating stall phenomenon in axial and centrifugal compressors with detailed descriptions of stall precursors and its development with time. Results showed that the vaneless region of the centrifugal compressor is the most critical location affected by stall. It was found that the tip leakage flow and the back flow impingement are the main cause of the stall development at the impeller exit area for centrifugal compressors. The results of the axial compressor simulations indicated that the early separated flow combined with the tip leakage flow can block the impeller passages during stall.

Compressor Surge Control Design Using Linear Matrix Inequality Approach

OpenAIRE

Uddin, Nur; Gravdahl, Jan Tommy

2017-01-01

A novel design for active compressor surge control system (ASCS) using linear matrix inequality (LMI) approach is presented and including a case study on piston-actuated active compressor surge control system (PAASCS). The non-linear system dynamics of the PAASCS is transformed into linear parameter varying (LPV) system dynamics. The system parameters are varying as a function of the compressor performance curve slope. A compressor surge stabilization problem is then formulated as a LMI probl...

Studies about interaction of hydrogen isotopes with metals and intermetallic compounds

International Nuclear Information System (INIS)

Vasut, F.; Anisoara, P.; Zamfirache, M.

2003-01-01

Hydrogen is a non-toxic but highly inflammable gas. Compared to other inflammable gases, its range of inflammability in air is much broader (4-74.5%) but it also vaporizes much more easily. Handling of hydrogen in form of hydrides enhances safety. The interaction of hydrogen with metals and intermetallic compounds is a major field within physical chemistry. Using hydride-forming metals and intermetallic compounds, for example, recovery, purification and storage of heavy isotopes in tritium containing system can solve many problems arising in the nuclear-fuel cycle. The paper presents the thermodynamics and the kinetics between hydrogen and metal or intermetallic compounds. (author)

Identification of a new pseudo-binary hydroxide during calendar corrosion of (La, Mg)2Ni7-type hydrogen storage alloys for Nickel-Metal Hydride batteries

Science.gov (United States)

Monnier, J.; Chen, H.; Joiret, S.; Bourgon, J.; Latroche, M.

2014-11-01

To improve the performances of Nickel-Metal Hydride batteries, an important step is the understanding of the corrosion processes that take place in the electrode material. In particular, the present study focuses for the first time on the model (La, Mg)2Ni7 system. The calendar corrosion in 8.7 M KOH medium was investigated from 6 h to 16 weeks immersion. By a unique combination of structural and elemental characterisations, the corrosion products are evidenced in those systems. In particular, we demonstrate that Ni and Mg combine in a pseudo-binary hydroxide Mg1-xNix(OH)2 whereas La corrodes into nanoporous La(OH)3 needles with inner hollow nanochannels.

Life cycle environmental assessment of lithium-ion and nickel metal hydride batteries for plug-in hybrid and battery electric vehicles.

Science.gov (United States)

Majeau-Bettez, Guillaume; Hawkins, Troy R; Strømman, Anders Hammer

2011-05-15

This study presents the life cycle assessment (LCA) of three batteries for plug-in hybrid and full performance battery electric vehicles. A transparent life cycle inventory (LCI) was compiled in a component-wise manner for nickel metal hydride (NiMH), nickel cobalt manganese lithium-ion (NCM), and iron phosphate lithium-ion (LFP) batteries. The battery systems were investigated with a functional unit based on energy storage, and environmental impacts were analyzed using midpoint indicators. On a per-storage basis, the NiMH technology was found to have the highest environmental impact, followed by NCM and then LFP, for all categories considered except ozone depletion potential. We found higher life cycle global warming emissions than have been previously reported. Detailed contribution and structural path analyses allowed for the identification of the different processes and value-chains most directly responsible for these emissions. This article contributes a public and detailed inventory, which can be easily be adapted to any powertrain, along with readily usable environmental performance assessments.

Modal characteristics and fatigue strength of compressor blades

International Nuclear Information System (INIS)

Kim, Kyung Kook; Lee, Young Shin

2014-01-01

High-cycle fatigue (HCF) has been identified as one of the primary causes of gas turbine engine failure. The modal characteristics and endurance strength of a 5 MW gas turbine engine blade developed by Doosan Heavy Industries and Construction Co., Ltd. in HCF fracture were verified through analysis and tests to determine the reliability of the compressor blade. A compressor blade design procedure that considers HCF life was performed in the following order: airfoil and blade profile design, modal analysis, stress distribution test, stress endurance limit test, and fatigue life verification. This study analyzed the Campbell diagram and estimated resonance risk on the basis of the natural frequency analysis and modal test of the compressor blade to guarantee safe and operational reliability. In addition, the maximum stress point of the compressor blade was determined through stress distribution analysis and test. The bonding point of the strain gage was determined by using fatigue test. Stress endurance limit test was performed based on the results of these tests. This research compared and verified the modal characteristics and endurance strengths of the compressor blades to prevent HCF fracture, which is among the major causes of gas turbine engine damage. A fatigue life design procedure of compressor blades was established. The 5 MW class gas turbine compressor blade is well designed in terms of resonance stability and fatigue endurance limit.

Modal characteristics and fatigue strength of compressor blades

Energy Technology Data Exchange (ETDEWEB)

Kim, Kyung Kook [Doosan Heavy Industries and Construction, Changwon (Korea, Republic of); Lee, Young Shin [Chungnam National University, Daejeon (Korea, Republic of)

2014-04-15

High-cycle fatigue (HCF) has been identified as one of the primary causes of gas turbine engine failure. The modal characteristics and endurance strength of a 5 MW gas turbine engine blade developed by Doosan Heavy Industries and Construction Co., Ltd. in HCF fracture were verified through analysis and tests to determine the reliability of the compressor blade. A compressor blade design procedure that considers HCF life was performed in the following order: airfoil and blade profile design, modal analysis, stress distribution test, stress endurance limit test, and fatigue life verification. This study analyzed the Campbell diagram and estimated resonance risk on the basis of the natural frequency analysis and modal test of the compressor blade to guarantee safe and operational reliability. In addition, the maximum stress point of the compressor blade was determined through stress distribution analysis and test. The bonding point of the strain gage was determined by using fatigue test. Stress endurance limit test was performed based on the results of these tests. This research compared and verified the modal characteristics and endurance strengths of the compressor blades to prevent HCF fracture, which is among the major causes of gas turbine engine damage. A fatigue life design procedure of compressor blades was established. The 5 MW class gas turbine compressor blade is well designed in terms of resonance stability and fatigue endurance limit.

Experimental Pressure-Volume diagrams of scroll compressors

OpenAIRE

Picavet, Alain; Ginies, Pierre

2014-01-01

This paper presents the results of tests led with scroll compressors to establish pressure-volume diagrams. Two compressors were thinly instrumented with pressure and displacement sensors so as to follow the whole compression process, from suction to exhaust. A gear coder was set to mark off the closing and opening of gas pockets, and to study the speed variations occurring during a single rotation. These tests help to understand the various phenomena met in a compressor, such as back-flow, o...

Stress analysis of hydride bed vessels used for tritium storage

International Nuclear Information System (INIS)

McKillip, S.T.; Bannister, C.E.; Clark, E.A.

1991-01-01

A prototype hydride storage bed, using LaNi 4.25 Al 0.75 as the storage material, was fitted with strain gages to measure strains occurring in the stainless steel bed vessel caused by expansion of the storage powder upon uptake of hydrogen. The strain remained low in the bed as hydrogen was added, up to a bed loading of about 0.5 hydrogen to metal atom ratio (H/M). The strain then increased with increasing hydrogen loading (∼ 0.8 H/M). Different locations exhibited greatly different levels of maximum strain. In no case was the design stress of the vessel exceeded

The behavior of hydrogen in metals

International Nuclear Information System (INIS)

Hirabayashi, Makoto

1975-01-01

Explanation is made on the equilibrium diagrams of metal-hydrogen systems and the state of hydrogen in metals. Some metals perform exothermic reaction with hydrogen, and the others endothermic reaction. The former form stable hydrides and solid solutions over a wide range of composition. Hydrogen atoms in fcc and bcc metals are present at the interstitial positions of tetrahedron lattice and octahedron lattice. For example, hydrogen atoms in palladium are present at the intersititial positions of octahedron. When the ratio of the composition of hydrogen and palladium is 1:1, the structure becomes NaCl type. Hydrogen atoms in niobium and vanadium and present interstitially in tetrahedron lattice. Metal hydrides with high hydrogen concentration are becoming important recently as the containers of hydrogen. Hydrogen atoms diffuse in metals quite easily. The activation energy of the diffusion of hydrogen atoms in Nb and V is about 2-3 kcal/g.atom. The diffusion coefficient is about 10 -5 cm 2 /sec in alpha phase at room temperature. The number of jumps of a hydrogen atom between neighboring lattice sites is 10 11 --10 12 times per second. This datum is almost the same as that of liquid metals. Discussion is also made on the electronic state of hydrogen in metals. (Fukutomi, T.)

Real-time trend monitoring of gas compressor stations

Energy Technology Data Exchange (ETDEWEB)

Van Hardeveld, T. (Nova, an Alberta Corp., AB (Canada))

1991-02-01

The authors' company has developed a machinery health monitoring system (MHealth) for short-term and long-term historical trending and analysis of data from its 40 gas compressor stations. The author discusses the benefits of real-time trending in troubleshooting operations, in preventative maintenance scheduling and cites specific applications in the startup operations of several new gas compressor/centrifugal compressor units.

A high pressure centrifugal oxygen compressor

International Nuclear Information System (INIS)

Larsen, L.P.

1986-01-01

The application of a centrifugal compressor train to 5860 kPa(g) (850 psig) for a coal gasification plant is discussed. Special considerations in the application, installation, and operation of the equipment are presented. Discussion includes such topics as compressor controls, machinery protection, noise, personnel safety, and operation of the equipment

Preparation and hydrogen-deuterium exchange of alkyl and hydride bis(trimethylsilyl)amido derivatives of the actinide elements

International Nuclear Information System (INIS)

Simpson, S.J.; Turner, H.W.; Andersen, R.A.

1981-01-01

The monomeric, hydrocarbon-soluble monohydrides and monodeuterides of the actinide metals (thorium or uranium) of the type HM[N(SiMe 3 ) 2 ] 3 have been prepared. Their reaction chemistry - n-BuLi followed by MeBr yields MeM[N(SiMe 3 ) 2 ] 3 and borane in tetrahydrofuran yields BH 4 M[N(SiMe 3 ) 2 ] 3 - suggests that the hydrogen atom is hydridic. Pyrolysis of the hydrides yields the novel, four-membered ring metallacycle [(Me 3 Si) 2 N] 2 MCH 2 Si(Me) 2 NSiMe 3 where M is Th or U. These metallacycles are the key intermediates in the hydrogen-deuterium exchange reaction that yields ([CD 3 ) 3 Si] 2 N) 3 MD

The influence of hydride on fracture toughness of recrystallized Zircaloy-4 cladding

Energy Technology Data Exchange (ETDEWEB)

Hsu, Hsiao-Hung, E-mail: 175877@mail.csc.com.tw [Institute of Nuclear Energy Research (INER), Lungtan Township, Taoyuan County 32546, Taiwan, ROC (China); China Steel Corporation, Hsiao Kang District, Kaohsiung 81233, Taiwan, ROC (China); Chiang, Ming-Feng [China Steel Corporation, Hsiao Kang District, Kaohsiung 81233, Taiwan, ROC (China); Chen, Yen-Chen [Institute of Nuclear Energy Research (INER), Lungtan Township, Taoyuan County 32546, Taiwan, ROC (China)

2014-04-01

In this work, RXA cladding tubes were hydrogen-charged to target hydrogen content levels between 150 and 800 wppm (part per million by weight). The strings of zirconium hydrides observed in the cross sections are mostly oriented in the circumferential direction. The fracture toughness of hydrided RXA Zircaloy-4 cladding was measured to evaluate its hydride embrittlement susceptibility. With increasing hydrogen content, the fracture toughness of hydrided RXA cladding decreases at both 25 °C and 300 °C. Moreover, highly localized hydrides (forming a hydride rim) aggravate the degradation of the fracture properties of RXA Zircaloy-4 cladding at both 25 °C and 300 °C. Brittle features in the form of quasi-cleavages and secondary cracks were observed on the fracture surface of the hydride rim, even for RXA cladding tested at 300 °C.

Ultra-sonic observation in niobium hydride precipitation

International Nuclear Information System (INIS)

Florencio, O.; Pinatti, Dyonisio G.

1982-01-01

The hidrogen embrittlement of exothermic ocluders, had been considered as due to applied stress induced hydride precipitates leading to brittle fracture. The results of simultaneous measurements of macroscopic deformation and elastic change due to hydride precipitation, using the ultrasonic pulse-echo technique are showed. THen it was tested the possibility of kinectis precipitation parameters evoluation. (Author) [pt

Morphology study on the depleted uranium as hydriding/dehydriding cycles

Energy Technology Data Exchange (ETDEWEB)

Chung, Dong-you, E-mail: dongyou@nfri.re.kr [National Fusion Research Institute, Daejeon (Korea, Republic of); Yun, Sei-Hun; Kang, Hyun-Goo; Chang, Min Ho; Oh, Yun Hee [National Fusion Research Institute, Daejeon (Korea, Republic of); Kang, Kweon Ho; Woo, Yoon Myung [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2016-11-01

Depleted Uranium (DU) is one of the strongest candidates as a getter material of hydrogen isotopes in the nuclear fusion reactor. In this work, small DU lump specimen with 99.8% purity was prepared for observation of morphology variation as hydriding/dehydriding cycles. Hydriding/dehydriding of DU was carried out more than 10 cycles for powder preparation. The pulverized DU specimen was safely handled in the glove box under Argon gas condition to minimize contact with oxygen and humidity. The morphology change according to hydriding/dehydriding cycles was observed by visual cell reactor, optical microscope and scanning electron microscope. The first hydriding of the small DU sample has progressed slowly with surface enlargement and volume expansion as time passes. After third hydriding/dehydriding cycles, most of DU was pulverized. The powder fineness of DU developed as hydriding/dehydriding cycle progresses. But the agglomerates of fine DU particles were observed. It was confirmed that the DU particles exist as porous agglomerates. And the particle agglomerate shows poor fluidity and even has the cohesive force.

Sound reduction of air compressors using a systematic approach

Science.gov (United States)

Moylan, Justin Tharp

The noise emitted by portable electric air compressors can often be a nuisance or potentially hazardous to the operator or others nearby. Therefore, reducing the noise of these air compressors is desired. This research focuses on compressors with a reciprocating piston design as this is the most common type of pump design for portable compressors. An experimental setup was developed to measure the sound and vibration of the air compressors, including testing inside a semi-anechoic chamber. The design of a quiet air compressor was performed in four stages: 1) Teardown and benchmarking of air compressors, 2) Identification and isolation of noise sources, 3) Development of individual means to quiet noise sources, 4) Selection and testing of integrated solutions. The systematic approach and results for each of these stages will be discussed. Two redesigned solutions were developed and measured to be approximately 65% quieter than the previous unmodified compressor. An additional analysis was performed on the solutions selected by the participants involved in the selection process. This analysis involved determining which of the design criteria each participant considered most important when selecting solutions. The results from each participant were then compared to their educational background and experience and correlations were identified. The correlations discovered suggest that educational background and experience may be key determinants for the preference models developed.

40 CFR 63.1031 - Compressors standards.

Science.gov (United States)

2010-07-01

... the compressor drive shaft seal to a process or a fuel gas system or to a closed vent system that... specified in the referencing subpart. (b) Seal system standard. Each compressor shall be equipped with a seal system that includes a barrier fluid system and that prevents leakage of process fluid to the...

Investigation of axial positioning for flexural compressors

Science.gov (United States)

Riggle, Peter

1991-01-01

The testing of the research compressor is presented. The research compressor was assembled and disassembled in order to show the consistency in which the piston and rod could be aligned with a .0004 inch radial gap around the piston. A full set of tests was completed for the first assembly, which is referred to as assembly no. 1. The compressor was disassembled and assembled a second time (assembly no. 2). Assembly no. 2 was only tested statically due to the time constraint. Results are discussed.

Pyrochemical processes for the recovery of weapons grade plutonium either as a metal or as PuO2 for use in mixed oxide reactor fuel pellets

International Nuclear Information System (INIS)

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

1995-01-01

The authors have developed two processes for the recovery of weapons grade Pu, as either Pu metal or PuO 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 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