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Showing papers on "Hydrogen storage published in 1982"


Journal ArticleDOI
J. Töpler1, H. Buchner1, H. Säufferer1, K. Knorr2, W. Prandl2 
TL;DR: In this paper, the diffusion constants of hydrogen in Mg-Mg 2 Ni were investigated using a quasi-elastic neutron scattering technique with a high resolution backscattering spectrometer.
Abstract: Mg 2 Ni and the mixed system Mg-Mg 2 Ni are used as hydrogen storage media for industrial applications. The mechanism of hydrogen charge and discharge in Mg-Mg 2 Ni is not yet completely understood particularly because the kinetics of hydrogen exchange in magnesium are strongly influenced by the Mg 2 Ni phase. In order to investigate hydrogen exchange in Mg-Mg 2 Ni the diffusion constants of hydrogen in both systems have been investigated separately using a quasi-elastic neutron scattering technique with a high resolution backscattering spectrometer. The results show that the diffusion of hydrogen in the α phase of Mg 2 Ni occurs more slowly than in the α phase of magnesium, so that the fast kinetics of hydrogen exchange in the combined system Mg-Mg 2 Ni are probably influenced by surface effects. The diffusion rate in the β phase of magnesium is smaller by three orders of magnitude than that in the α phase.

94 citations


Journal ArticleDOI
TL;DR: In this paper, the use of ammonia as a multipurpose energy vector was proposed for energy storage and transmission via pipeline to remote demand centers where some of it serves as a clean-burning fuel for local cogeneration and process heat applications, while others are used for direct agricultural application or as feedstock for production of nitrogen-based fertilizers or other chemical processes.

86 citations


Journal ArticleDOI
TL;DR: In this paper, three distinct hydride phases can be formed at room temperature and modest H2 pressures, named β, γ, and δ hydrides respectively, and the thermodynamics of the β and γ phases are presented along with comments on the tendency for CaNi5 to disproportionate when hydrided.

81 citations


Patent
29 Jul 1982
TL;DR: In this paper, a metal hydride heat pump system has a plurality of operating units, and the metal exchange medium of each operating unit is a combination of a first metal hyddride having a lower equilibrium dissociation pressure at the operating temperature and a second metal hyddide having higher equilibrium dissociative pressure at operating temperature, such that hydrogen can flow freely between the two hydrides.
Abstract: A metal hydride heat pump system has a plurality of operating units, the metal hydride heat exchange medium of each operating unit be a combination of a first metal hydride having a lower equilibrium dissociation pressure at the operating temperature and a second metal hydride having a higher equilibrium dissociation pressure at the operating temperature and the metal hydrides being such that hydrogen can flow freely between the two metal hydrides, wherein the equilibrium dissociation pressure characteristics of one or both of the first and second metal hydrides in a given operating unit differ from those of one or both of the first and second metal hydrides in at least one other operating unit.

66 citations


Journal ArticleDOI
TL;DR: In this article, the Zr 1− x Ti x MnFe-H 2 systems with x = 0.2 and 0.3 were studied as a function of composition, temperature, and hydrogen dissociation pressure (0.01-50 atm).
Abstract: The Zr 1− x Ti x MnFe-H 2 systems with x = 0.2 and 0.3 were studied as a function of composition, temperature (23–200 °C) and hydrogen dissociation pressure (0.01–50 atm). The hydrogen vapor pressure of the ZrMn 2 -H 2 system is raised approximately 400-fold by the replacement of zirconium by titanium and of manganese by iron without significantly impairing its hydrogen capacity. The hydrides of Zr 1− x Ti x MnFe alloys have dissociation pressures in the range 1–2 atm at room temperature (23 °C). The hydrogen densities of the alloys compared with that of liquid hydrogen range from about 1.0 to 1.4. The enthalpies and entropies of dehydrogenation are exceptionally low (10–11 kJ (mol H 2 ) −1 and 46–50 J (mol H 2 ) −1 K −1 respectively). The kinetics of hydrogen absorption and desorption are extremely fast. Desorption of hydrogen in the two-phase field α + β follows first-order kinetics with activation energies of 34–38 kJ mol −1 . The energetics of hydrogen charging and discharging for the Zr 0.8 Ti 0.2 MnFe alloy are smaller than those for LaNi 5 or other accepted hydrogen storage materials. Similarly, a hydride compressor using Zr 0.8 Ti 0.2 MnFe alloy appears to be significantly more efficient than the LaNi 5 hydride compressor.

52 citations


Journal ArticleDOI
TL;DR: In this paper, the effect of surface and bulk properties of FeTix on its hydrogen storage characteristics was investigated by X-ray photoelectron spectroscopy, Mossbauer and metallographic observations, and it was shown that several problems encountered with FeTi can be reduced if alloys with a non-equilibrium structure are prepared by the addition of excess titanium.
Abstract: The effect of the surface and bulk properties of FeTix (1 =⩽ x ⩽ 2) on its hydrogen storage characteristics was investigated by X-ray photoelectron spectroscopy, Mossbauer spectroscopy and metallographic observations. It is shown that several problems encountered with FeTi, such as the necessity of employing activation treatment and the surface sensitivity resulting from poisoning by impurity gases, can be reduced if alloys with a non-equilibrium structure are prepared by the addition of excess titanium.

48 citations


Journal ArticleDOI
TL;DR: In this article, the Gibbs-Duhem integration has been made to obtain the thermodynamic activity of titanium and the formation properties of the “TiH2” phase, and the interaction energies between neighboring atoms in the hydride have been evaluated by applying a quasi-chemical model of statistical mechanics.
Abstract: Hydrogen gas has been equilibrated with the hydrogen dissolved in titanium. The equilibrium pressure (<10 MPa) of the gas and the hydrogen concentration (40 ∼ 70 mol pct) in titanium have been measured at 576 to 980 K by Sieverts' method. A Gibbs-Duhem integration has been made to obtain the thermodynamic activity of titanium and the formation properties of the “TiH2” phase. Interaction energies between neighboring atoms in the hydride have been evaluated by applying a quasi-chemical model of statistical mechanics.

46 citations


PatentDOI
TL;DR: A metal hydride container, comprising a heat pipe of annular cross section, a metal hyddride filling the central cavity of said heat pipe, closure members serving to close the openings at the opposite ends of said central cavity, a hydrogen passage tube possessed of a shut-off valve and fitted into an aperture formed in one of said closure members and communicated with the cavity of the heat pipe through a partition member pervious to hydrogen gas and impervious to said metal hydide.

37 citations


Journal ArticleDOI
TL;DR: In this paper, it was shown that the surface damage can be prevented by controlling the current density and temperature of the LaNi5 electrodes, which is not serious as far as the hydrogen fugacity, being connected to the cathodic overpotential, was less than the equilibrium hydrogen pressure.

36 citations


Journal ArticleDOI
TL;DR: In this paper, pressure-composition isotherms with well-defined flat plateaux were obtained in this temperature range for x = 2, 2.5, 3.5.
Abstract: Hydrides of CeNi5−xCux (x = 2, 2.5, 3) were studied in the temperature range of 0–50 °C. Pressure-composition isotherms with well-defined flat plateaux were obtained in this temperature range for x = 2 and 2.5. Substitution of copper for nickel causes a substantial decrease in the hydrogen dissociation pressure. The substitution also lowers the alloy cost. The kinetics of absorption and desorption are extremely fast (90% of the absorption takes place in about 50 s). The heats ΔH of formation of the hydride system are low relative to the value for LaNi5-H2. The low value of ΔH together with the high absorption and desorption rates makes these compounds promising materials for technical applications, especially hydrogen storage.

35 citations


Journal ArticleDOI
TL;DR: The hydrogen absorption and desorption characteristics of misch metal-nickel-silicon alloys were investigated in this article, where the same hexagonal structure as LaNi5 and MmNi5 was used to form the hydrides MmNis5−ySiy.
Abstract: The hydrogen absorption and desorption characteristics of misch metal-nickel-silicon alloys were investigated. The alloys MmNis5−ySiy (Mm denotes misch metal and 0.4 ⩽ y ⩽ 0.8) were found to have the same hexagonal structure as LaNi5 and MmNi5, and they reacted readily with hydrogen to form the hydrides MmNi4.6 Si0.45H4.35, MmNi4.5 Si0.5H3.8, MmNi4.4Si0.6H2.1 and MmNi4.2Si0.8H3.1 (hydrogen contents of 1.0 wt.%, 0.9 wt.%, 0.5 wt.% and 0.7 wt.% respectively) under a hydrogen pressure of 60 atm at room temperature. The dissociation pressures of these hydrides were dependent on the silicon content (the silicon partially substitutes for nickel), and the value of log P became lower than that for MmNi5 hydride as y was increased. The enthalpy changes on hydride formation as determined from the dissociation isotherms for the MmNi4.5Si0.5-H and MmNi4.2Si0.8-H systems were −6.6 kcal (mol H2)−1 and −9.0 kcal (mol H2)−1 respectively; the value for the former was smaller than that for LaNi5, and the value for the latter was greater than those for LaNi5 and MmNi5. The dissociation pressures of these hydrides at 20 °C were 7.5 atm and 1.5 atm respectively. The desorption rate of hydrogen for MmNi4.2Si0.8 was larger than those for LaNi5 and MmNi5, and a value of 10.9–12.0 kcal mol−1 was obtained for the apparent activation energy of hydrogen desorption. The hydrides of MmNi4.6Si0.4, MmNi4.5Si0.5 and MmNi4.5Si0.8 have properties which make them suitable as stationary hydrogen storage materials.

Journal ArticleDOI
TL;DR: In this article, the magnetic properties of hydrides of the lanthanide elements and intermetallic compounds involving lanthanides and thorium are consistent with the concept that hydrogen acts as an electron acceptor.
Abstract: The magnetic properties of hydrides of the lanthanide elements and intermetallic compounds involving the lanthanides and thorium are consistent with the concept that hydrogen acts as an electron acceptor. The behavior of hydrides of LaNi 5− x Cu x is interpreted using photoemission studies and recent augmented plane wave band structure calculations on LaNi 5 .

Patent
28 Apr 1982
TL;DR: In this paper, a material for reversibly storing hydrogen is formed from a lightweight matrix which is chemically and structurally modified to improve its hydrogen storage properties, such as absorption and desorption properties.
Abstract: A material for reversibly storing hydrogen is formed from a lightweight matrix which is chemically and structurally modified to improve its hydrogen storage properties. The utilization of a material which can be any of a number of different disordered structures makes possible the modification of local order chemical environments of the material to increase hydrogen storage capacity and/or improve absorption and desorption properties. Lightweight modifier elements structurally modify the local chemical environments of the matrix to provide a material having an increased density of storage sites to increase hydrogen storage capacity. Transition and rare earth modifier elements structurally modify the local chemical environments to provide a material with an increased density of catalytically active sites for dissociating hydrogen molecules to increase the rate at which hydrogen absorption and desorption can be accomplished. The transition and rare earth modifier elements also structurally modify local order chemical environments to provide sites which store hydrogen atoms at lower bond energies to significantly reduce hydrogen desorption temperatures.

Journal ArticleDOI
TL;DR: In this article, photoemission studies of LaNi/sub 5-x/Cu/sub x/, with x ranging from 0 to 5, show Cu and Ni d bands clearly separated by about 2 eV, indicating that, while a partially empty d band is necessary for reasonable hydrogen storage capacity in a metal, there is an additional requirement to produce exothermal hydrogenation and hence extensive hydrogen solubility.
Abstract: Photoemission studies of LaNi/sub 5-x/Cu/sub x/, with x ranging from 0 to 5, show Cu and Ni d bands clearly separated by about 2 eV. The band in LaNi/sub 5/ closely resembles that of elemental Ni, and the d band in LaCu/sub 5/ closely resembles that of elemental Cu. The photoemission results have been successfully used to interpret trends in hydriding behavior of LaNi/sub 5/ as Ni is progressively replaced by Cu, viz., the decrease in capacity and the decrease in hydrogen vapor pressure. Analysis of the hydrogen-metal bonding in these systems indicates that, while a partially empty d band is necessary for reasonable hydrogen storage capacity in a metal, there is an additional requirement to produce exothermal hydrogenation and hence extensive hydrogen solubility. The additional requirement is that the d band must be located properly on the energy scale.

Journal ArticleDOI
TL;DR: In this paper, it was shown that ZrMn/sub 2/Fe/sub x/ reacts with hydrogen very readily to form very hydrogen-rich systems and the hydrogen is very labile.
Abstract: ZrMn/sub 2/Fe/sub x/ reacts with hydrogen very readily to form very hydrogen-rich systems. Hydrogen densities relative to liquid hydrogen are in the range 0.7 to 1.2. The hydrogen is very labile. Hydrogen vapor pressure increases rapidly with increasing x. The vapor pressure is increased more than 100-fold for ZrMn/sub 2/Fe/sub 0/ /sub 8/-H/sub 2/ and more than 1000-fold for ZrMn/sub 2/Fe/sub 1/ /sub 2/-H/sub 2/ compared to the ZrMn/sub 2/-H/sub 2/ system. The enthalpy and entropy of hydrogenation are exceptionally low with values in the range of -6.2 to -12.0 kJ/mol and -37.7 to -52.8 J/(mol K), respectively. The kinetics of hydrogen absorption and desorption processes in the alloy are very rapid; the processes are nearly complete within 1 min. The small values of the heat effects associated with hydrogenation and the rapid kinetics are particularly significant in regard to practical applications of ZrMn/sub 2/Fe/sub x/ alloys for hydrogen storage.

Journal ArticleDOI
TL;DR: An economic evaluation of alternative hydrogen storage methods (pressurized gas, metal hydride and cryogenic storage) for large stationary (utility-scale) applications is presented in this paper.

Journal ArticleDOI
TL;DR: In this paper, the authors present a review of the available evidence for hydrogen storage in the Friauf-Laves phase alloys (C14, C15, and Mg2NiH4).
Abstract: When hydrogen is absorbed in a metal or an alloy a small amount of absorption may take place without any structural change except for expansion. For the Friauf-Laves phase alloys (C14, C15), however, this is true for the whole absorption range. These alloys therefore offer excellent opportunities for studying site occupation as a function of composition. Several different phases are formed for the alloys of most interest for hydrogen storage (FeTi, LaNi5 and Mg2Ni). Their structures and relationships have been well established except in two important cases. This concerns LaNi5H6 where uncertainty exists both with regard to the space group and the number of sites for the hydrogen atoms. Similarly the phase relationships for Mg2NiH4 are not clear and the crystal structure is not yet solved. Present information is reviewed and the available evidence is discussed.

Journal ArticleDOI
TL;DR: In this article, the electronic structure of the hydrogen storage intermetallic compounds FeTi and FeTiH was studied using the augmented plane wave method with warped muffin tin corrections.
Abstract: The electronic structure of the hydrogen storage intermetallic compounds FeTiH and FeTiH 2 is studied using the augmented plane wave method with warped muffin tin corrections. The features of the total densities of states (DOSs) are used to explain the increase in the electronic specific heat coefficient and the increase in the Pauli susceptibility observed on hydrogenation. The composition of the states is discussed in light of a partial wave DOS analysis performed at the metal and at the hydrogen sites. Mossbauer isomer shift data are interpreted in terms of metal-hydrogen bonding, in addition to volume expansion effects. We also evaluate the electron-phonon coupling constant; our results indicate that the addition of hydrogen to FeTi should not lead to superconductivity.

Patent
13 Jan 1982
TL;DR: In this paper, a double pipe structural case is formed into the shape of concentric circles in its section and each of metallic hydrides 11 and 11' are stored in mutually independent cells 10 and 10' Simultaneously with a valve 18 closed, a valve 17 is opened, rendering a valve 21 open to the side of a pipe 19, and hydrogen is heated by generated occlusive heat 11' whereby the occluded hydrogen is discharged and fed to a fuel cell.
Abstract: PURPOSE:To improve the performance of a fuel cell as well as to make yet longer service life promotable, by forming a hydrogen storage case used for fuel into a double pipe structure capable of heat exchanging and thereby having metallic hydrides stored in the case CONSTITUTION:A double pipe structural case 9 is formed into the shape of concentric circles in its section and each of metallic hydrides 11 and 11' are stored in mutually independent cells 10 and 10' Simultaneously with a valve 18 closed, a valve 17 is opened, rendering a valve 21 open to the side of a pipe 19, and hydrogen is occluded into the metallic hydride 11 from a hydrogen source, then the metallic hydride 11' is heated by generated occlusive heat 11' whereby the occluded hydrogen is discharged and fed to a fuel cell 1 Doing like this, using heat produced when hydrogen is occluded into one of cells, the other cell is heated, making hydrogen discharge from the other cell ever so facile, so that such hydrogen as excellent in purity is able to be continuously fed to the fuel cell which therefore can produce electric power

Journal ArticleDOI
M.S. Bawa1, E.A. Ziem1
TL;DR: In this article, a long-term test in excess of 5000 charge/discharge cycles demonstrated good stability of the CaNi5 alloy in a longterm test with a hydrogen working capacity of 0.8% by weight.

Journal ArticleDOI
TL;DR: Zr0.7Ti0.3Mn2Fe0.8 hydride was prepared and studied as a function of temperature (25-200 °C) and hydrogen equilibrium pressure (0.01-50 atm) as discussed by the authors.
Abstract: Zr0.7Ti0.3Mn2Fe0.8 hydride was prepared and studied as a function of temperature (25–200 °C) and hydrogen equilibrium pressure (0.01–50 atm). The vapor pressure of the quaternary hydride system is approximately 1000 times larger than that of the ZrMn2-H2 system. The hydrogen density of the alloy relative to liquid hydrogen is 0.7. The enthalpy and entropy of hydrogenation are very low, being −14.1 kJ mol-1 and−59.5 J mol-1 K-1 respectively. The low value of ΔH α → β and the rapid kinetics of hydrogen absorption-desorption processes are particularly significant in regard to practical applications of Zr1−xTixMn2Fey alloys for hydrogen storage.

Journal ArticleDOI
K. Binder1, G. Withalm1
TL;DR: In this article, a concept is derived for a safe hydrogen engine with favorable fuel consumption, which will be tested in a vehicle fleet and evaluated with this experience it will finally be assessed which mixture formation combination will have to be favored in the future.

Patent
09 Jun 1982
TL;DR: In this article, a layer of an amorphous binary metallloy of a lanthanide and iron, nickel or cobalt is disposed on a suitable substrate and overcoated with palladium metal.
Abstract: A solid-state hydrogen storage system. A layer of an amorphous binary metallloy of a lanthanide and iron, nickel or cobalt is disposed on a suitable substrate and overcoated with palladium metal.

Journal ArticleDOI
TL;DR: The hydrogen storage material LaNi5 has previously been shown to degrade into LaH2 and (presumably) Ni metal on repeated absorption and desorption of hydrogen as mentioned in this paper.
Abstract: The hydrogen storage material LaNi5 has previously been shown to degrade into LaH2 and (presumably) Ni metal on repeated absorption and desorption of hydrogen. 61Ni Mossbauer measurements show directly the presence of nickel microprecipitates in severely degraded material.

Journal ArticleDOI
TL;DR: In this article, the authors compared the on-board storage costs of a single vehicle and a large-scale stationary hydrogen storage facility in terms of the total primary energy flow for different design ranges.

Journal ArticleDOI
TL;DR: Several of the ZrMn/sub 2/-based systems have been investigated as materials for hydrogen storage as discussed by the authors, and they appear to be excellent candidates with favorable capacity (higher volumetric capacity than liquid hydrogen), kinetics, and pressure-composition characteristics.
Abstract: Several of the ZrMn/sub 2/-based systems ZrMn/sub 2/Mn/sub y/Fe/sub x/ have been investigated as materials for hydrogen storage. They appear to be excellent candidates. They have favorable capacity (higher volumetric capacity than liquid hydrogen), kinetics, and pressure-composition characteristics. Also, hydride decomposition is only slightly endothermal (..delta..H ranges from approx. 15 to 22 kJ/(mol of H/sub 2/)) so that little of the energy associated with hydrogen is lost during hydride formation. This and the small heat flow problem occasioned by the small ..delta..H together with the other favorabele features make these systems of interest as practical materials for hydrogen storage.

Journal ArticleDOI
TL;DR: In this article, the authors used the results of self-consistent augmented plane wave calculations for ZrV 2 and ZrCo 2 as the basis for a muffin tin Green's function study of dilute hydrogen impurities.
Abstract: In experiments by Peretz et al. on the pseudobinary system Zr(V x −Co 1− x )in2 , an order-of-magnitude increase has been found in the hydrogen affinity at the vanadium-rich end compared with that at the cobalt-rich end. Didisheim et al . have identified the tetrahedral interstitial sites as the positions at which hydrogen (or deuterium) atoms are located. To investigate the hydrogen storage behavior in these compounds we have used the results of self-consistent augmented plane wave calculations for ZrV 2 and ZrCo 2 as the basis for a muffin tin Green's function study of dilute hydrogen impurities. We provide an evaluation of the applicability of this method (with suitable generalization) to the hydrides of Laves phases and discuss the self-consistent defect charge and state densities and their implications for bonding in these systems.


Patent
21 May 1982
TL;DR: In this paper, the authors present an apparatus for the storage and production of hydrogen from a solid compound, a compound of at least one rare earth and a metal of group VIII of the periodic system, which can selectively fix hydrogen by hydrogenation.
Abstract: OF THE DISCLOSURE The present invention relates to an apparatus for the storage and production of hydrogen from a solid compound. The solid compound is a compound of at least one rare earth and a metal of group VIIIof the periodic system, which can selectively fix hydrogen by hydrogenation. It is placed within a sealed container and is in a compact and machinable or workable form. Application to the storage of hydrogen. (Single drawing)

Patent
28 Sep 1982
TL;DR: An oxygen stabilized intermetallic compound with the formula Zr x OV y where x = 0.7 to 2.0 and y=0.18 to 0.33 was proposed in this paper.
Abstract: An oxygen stabilized intermetallic compound having the formula Zr x OV y where x=0.7 to 2.0 and y=0.18 to 0.33. The compound is capable of reversibly sorbing hydrogen at temperatures from -196° C. to 450° C. at pressures down to 10 -6 Torr. The compound is also capable of selectively sorbing hydrogen from gaseous mixtures in the presence of CO and CO 2 .