Showing papers on "Hydrogen storage published in 1980"
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TL;DR: In this paper, the authors showed that the irradiation of the carbohydrates, not only sugar or starch but also cellulose, in the presence of water and a RuO2/TiO 2/Pt photocatalyst powder leads to the efficient production of hydrogen gas.
Abstract: Attempts have been made to find green plants which produce low-molecular weight hydrocarbons1,2 and to find seaweeds which produce hydrogen from water utilizing solar energy3,4. These attempts are aimed at finding methods of making use of the photosynthetic process in plants for direct production. Most green plants, however, synthesize carbohydrates, such as sugar, starch and/or cellulose, from water and carbon dioxide. The C4 plants5, such as corns and sugar cane, grow rapidly, utilizing solar energy with ∼1% efficiency for the fixation of CO2. This value is 10 times larger than that of the average efficiency of photosynthesis of plants, 0.1%. However, the carbohydrates produced by these plants cannot be used directly as fuel. Here we show a new route for the conversion of carbohydrates into hydrogen (a clean fuel in the hydrogen energy system), taking advantage of the photocatalytic process. We found that the irradiation of the carbohydrates, not only sugar or starch but also cellulose, in the presence of water and a RuO2/TiO2/Pt photocatalyst powder leads to the efficient production of hydrogen gas.
552 citations
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TL;DR: In this article, the authors bring together engineering properties for three classes of hydride-forming alloys (AB, AB5 and A2B) manufactured and marketed by Ergenics under the HY-STOR trade name.
Abstract: Rechargeable metal hydrides are being used for a wide variety of applications: mobile and stationary hydrogen storage, hydrogen purification, hydrogen recovery and separation, thermal compression, chemical heat pumps and refrigeration. Successful selection of metal hydrides for these and other proposed applications requires the knowledge of many engineering properties. In many cases these data are scattered widely in the literature or are simply not available.
In this paper we bring together engineering properties for three classes of hydride-forming alloys (AB, AB5 and A2B) manufactured and marketed by Ergenics under the HY-STOR trade name. The properties discussed are the plateau pressure-temperature relationship, hysteresis, the plateau slope, the hydrogen capacity and the heat capacity.
176 citations
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TL;DR: In this paper, a review of the dynamic response of hydrogen storage alloys is presented, including the determination of dynamic reaction kinetics and the comparison of dynamic and conventional pressure-composition-temperature relations.
Abstract: A brief review of the dynamic response of hydrogen storage alloys is presented. This includes the determination of dynamic reaction kinetics and the comparison of dynamic and conventional pressure-composition-temperature relations. Alloys of both AB5 and AB types were tested at pressures and temperatures of practical interest. Examples are shown of differences in reaction rate due to effects of intrinsic chemical kinetics, alloy hydrogen capacity and plateau pressure, and heat transfer limitations. Plateau pressures and reaction enthalpies for continuous-dynamic tests are shown to be different from those for conventional step-by-step tests. Also an apparent cyclic instability in the FeTiH2 phase is described.
127 citations
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TL;DR: In this paper, X-ray and neutron diffraction experiments performed on Mg2Ni(H,D)x (0 ⊽ x ⩽ 3.9) confirmed the existence of a structural phase transformation at about 235 °C.
Abstract: X-ray and neutron diffraction experiments performed on Mg2Ni(H,D)x (0 ⩽ x ⩽ 3.9) confirmed the existence of a structural phase transformation at about 235 °C. The high temperature phase (a = 6.49 A, space group Fm3m) has an antifluorite-type metal structure in which the deuterium atoms surround the nickel atoms octahedrally in a disordered manner (D−Ni =1.47 A, D−Mg = 2.30 A). Refined atomic parameters of Mg2Ni as well as absorption and desorption isotherms for the deutende and hydride phases are reported.
122 citations
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TL;DR: In this article, the authors investigated the techniques and economics of hydrogen storage by means of cryoadsorption and compared them with alternative storage methods and showed that the hydrogen storage capacity of several adsorbents in the temperature range 65-150 K has been investigated experimentally.
104 citations
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TL;DR: The hydriding behavior of the LnMg12, Ln2Mg17 and Ln5Mg41 alloys (Ln = La, Ce or mischmetal) has been investigated in this paper.
92 citations
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TL;DR: The storage of hydrogen as a metal hydride is discussed in this paper, where properties of some representative hydrogen-storage mediums (MgH/sub 2/, Mg/sub 1/NiH/Sub 4), VH/ sub 2/, FeTiH/1/ /sub 95/, LaNi/sub 5/H/s 7/H-sub 7, liquid hydrogen, and gaseous hydrogen) are compared.
Abstract: The storage of hydrogen as a metal hydride is discussed. Properties of some representative hydrogen-storage mediums (MgH/sub 2/, Mg/sub 2/NiH/sub 4/, VH/sub 2/, FeTiH/sub 1/ /sub 95/, LaNi/sub 5/H/sub 7/, liquid hydrogen, and gaseous hydrogen) are compared. Magnesium hydride, the more promising of the two binary hydrides, is thought to be only a borderline possibility as a hydrogen-storage medium at present. Of the three ternary hydrides listed the leading contender is iron-titanium hydride. It's main advantage over lanthanum-pentanickel hydride is one of cost. All the metal hydrides listed have a higher hydrogen storage capacity than an equal volume of liquid or gaseous hydrogen has. Energy densities (watt-hours per kilogram) of various automotive power sources either already in existence or proposed are tabulated. Metal hydrides lag far behind gasoline in terms of energy density, but they are competitive with electric batteries in this respect.
89 citations
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TL;DR: In this paper, the absorption of hydrogen by the magnesium-rich alloys LnMg12 (Ln La, Ce, mischmetal), La2M17 and Ce5Mg41 was investigated.
Abstract: The absorption of hydrogen by the magnesium-rich alloys LnMg12 (Ln La, Ce, mischmetal), La2M17 and Ce5Mg41 was investigated. The alloys decompose during hydriding to give magnesium hydride and the corresponding rare earth hydride. A comparative study of the hydriding and dehydriding processes was carried out at two different temperatures. In addition, alloys with compositions corresponding to the formula CeMg11M (M V, Cr, Mn, Fe, Co, Ni, Cu, Zn) were prepared and their absorption and desorption rates were compared with those of CeMg12 and La2Mg17. The hydriding rate is not changed significantly by the presence of a 3d element but the dehydriding rate is greatly enhanced by the presence of vanadium, chromium, manganese, iron or nickel. These results are discussed.
85 citations
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TL;DR: The reaction of hydrogen with commercially pure magnesium powder (above 99.7%) was investigated in the temperature range 250-400 °C as discussed by the authors, where hydrogen is readily sorbed above the dissociation pressure.
Abstract: The reaction of hydrogen with commercially pure magnesium powder (above 99.7%) was investigated in the temperature range 250–400 °C. Hydrogen is readily sorbed above the dissociation pressure. During the initial exposure the magnesium powder sorbs hydrogen slowly below 400 °C but during the second exposure the sorption is fast from about 250 °C and is nearly completed when 400 °C is reached after 10 min; no change in the sorption rate is observed with further cycling. In most experiments the resultant hydride is close to stoichiometric MgH2. Desorption is found to be slower and to require higher temperatures than sorption but is still practicable. Comparisons of powders with particle sizes ranging from less than 37 μm to more than 500 μm indicate that the specific surface area is the rate-determining factor. Scanning electron micrographs show that after sorption the particles become spongy. The fact that the particles do not disintegrate is explained by a sintering process at the working temperatures. Exposure to air does not impair the sorption ability; on the contrary, it appears that surface oxidation plays an important role in the reaction. Some handling problems, e.g. the reaction of the hydride with water vapour in air of normal humidity, were also investigated.
75 citations
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TL;DR: The hydrogen storage compound LaNi5 is an exchange-enhanced Pauli paramagnet with susceptibility chi (LaNi5)=4.6*10-6 EMU g-1.3*10 6 EMU 1.0).
Abstract: The hydrogen storage compound LaNi5 is an exchange-enhanced Pauli paramagnet with susceptibility chi (LaNi5)=4.6*10-6 EMU g-1. Hydrogen absorption leads to a decrease of the susceptibility of chi (LaNi5H6.0)=1.3*10-6 EMU g-1. This decrease is usually covered by a strong irreversible increase of surface magnetism, where, through surface segregation and decomposition, superparamagnetic Ni precipitations are formed. The two effects explain the controversial results about the magnetic properties of the LaNi5 hydride. The implication of this decomposition on the cyclic lifetime is discussed.
72 citations
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07 Mar 1980
TL;DR: In this article, a self-cleaning filter system was proposed to remove water impurities from hydrogen gas using an adsorbent capable of adsorbing water from the gas stream.
Abstract: Oxygen and water impurities are cleaned from hydrogen, which is to be stored in tanks containing a hydride-forming metallic alloy, using a novel, self-cleaning filter system. The impurity-containing hydrogen gas is first passed through a catalyst bed comprising a catalyst which is adapted to convert oxygen in the presence of hydrogen to water. The gas then passes through an adsorbent capable of adsorbing water from the gas stream, thereby substantially removing water impurities from the hydrogen gas. The purified hydrogen gas is charged into a storage tank containing a hydride-forming metallic alloy which absorbs the hydrogen by reacting therewith to form hydrogen-loaded metallic hydride. When the storage tank is to be discharged, the hydrogen-loaded metallic hydride in the tank is treated to release hydrogen gas therefrom. The released gas is passed back through the adsorbent, thereby cleaning the adsorbent of water impurities deposited therein when the tank was being charged with hydrogen. The hydrogen gas containing water impurities is then forwarded to a hydrogen utilization unit for further use of the hydrogen.
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03 Mar 1980TL;DR: Improved power cycles for improving the production of power and refrigeration and for conserving thermal energy, utilizing as a common basic characteristic, a hydride-dehydride-hydrogen power cycle in which hydrogen is reversibly combined with a homogeneous forming material at a relatively low temperature and pressure, the hydrided material is then heated at constant volume to chemically compress the hydrogen, and finally the material is dehydrided by further heating the material to release hydrogen gas at relatively high pressure and temperature as mentioned in this paper.
Abstract: Improved power cycles for improving the production of power and refrigeration and for conserving thermal energy, utilizing as a common basic characteristic, a hydride-dehydride-hydrogen power cycle in which hydrogen is reversibly combined with a hydride-forming material at a relatively low temperature and pressure, the hydrided material is then heated at constant volume to chemically compress the hydrogen, and finally the material is dehydrided by further heating the material to release hydrogen gas at relatively high pressure and temperature. The pressurized high temperature hydrogen gas as thus developed is used in various ways for producing power and refrigeration, including functioning as a low temperature heat sink for certain auxiliary or ancillary power cycles, prior to recycling the hydrogen gas for reuse in the described hydride-dehydride-hydrogen cycle.
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20 Mar 1980
TL;DR: In this article, a system for supplying hydrogen to an apparatus which utilizes hydrogen contains a metal hydride hydrogen supply component and a micro-cavity hydrogen storage component which in tandem supply hydrogen for the apparatus.
Abstract: A system for supplying hydrogen to an apparatus which utilizes hydrogen contains a metal hydride hydrogen supply component and a microcavity hydrogen storage hydrogen supply component which in tandem supply hydrogen for the apparatus. The metal hydride hydrogen supply component includes a first storage tank filled with a composition which is capable of forming a metal hydride of such a nature that the hydride will release hydrogen when heated but will absorb hydrogen when cooled. This first storage tank is equipped with a heat exchanger for both adding heat to and extracting heat from the composition to regulate the absorption/deabsorption of hydrogen from the composition. The microcavity hydrogen storage hydrogen supply component includes a second tank containing the microcavity hydrogen supply. The microcavity hydrogen storage contains hydrogen held under high pressure within individual microcavities. The hydrogen is released from the microcavities by heating the cavities. This heating is accomplished by including within the tank for the microcavity hydrogen storage a heating element.
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TL;DR: A limited survey of hydrogen and deuterium sorption by 13 selected AB itx alloys (A La, Ce, Pr, Er; B ǫ Co, Ni, La 0.45 Ce 0.55 Ni 5 and Lao 0.5 Co 5 ) was conducted in this paper.
Abstract: A limited survey was conducted of hydrogen and deuterium sorption by 13 selected AB itx alloys (A La, Ce, Pr, Er; B Co, Ni). A structural analysis showed that AB 5 hydrides (PrCo 5 H 3.9 and LaNi 5 H 6 are paradigms) share essentially the same structure, with a maximum of nine sites per AB 5 unit available for hydrogen storage. To determine whether all nine sites could be filled at pressures higher than those previously studied, pressure-composition isotherms were obtained at 21 °C and up to 1500 atm for each of the alloys under study. The greatest hydrogen absorption occurred for LaCo 5 , La 0.45 Ce 0.55 Ni 5 and Lao.5Ce 0.5 Co 5 with 9, 8.3 and 8.5 hydrogen atoms per mole of alloy respectively. The effect on the pressure-composition isotherm of substituting one A or B element for another (neodymium or manganese) who also explored. The pressure plateaus were usually shifted by these substitutions.
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TL;DR: In this paper, the authors studied the hydrogen absorption-desorption characteristics of ternary alloys such as Mm1−x AxNi5 (A Ca, Ti; x = 0.05− 0.75), MmNi5−yBy (B ǫ, Co, Cr, Mn, V, V; x= 0.1−0.75).
Abstract: Fundamental studies were carried out to develop hydrides of mischmetal-nickel (Mm-Ni) and Ti-Co alloys with suitable properties for use as stationary hydrogen storage materials. In order to improve the properties of MmNi5 and TiCo hydrides we studied the hydrogen absorption-desorption characteristics of ternary alloys such as Mm1−x AxNi5 (A Ca, Ti; x = 0.1−0.75), MmNi5−yBy (B Al, Co, Cr, Mn; y = 0.1 − 4), Ti1−xAxCo and TiCO1−x Ax (A Cr, Cu, Fe, La, Mn, Ni, V; x = 0.05− 0.5). The hydrides of MmNi4.5Al0.5, MmNi2.5Co2.5, MmNi4.5Cr0.5, MmNi4.5Mn0.5, TiCo0.5Mn0.5 and TiCo0.5Fe0.5, judged according to an appropriate set of criteria, rank higher than or equal to those of LaNi5, MmNi5, TiFe and TiCo and have properties suitable for a stationary hydrogen storage material.
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TL;DR: By means of conversion electron Mossbauer Spectroscopy (CEMS) Fe clusters have been found on the surface of activated TiFe specimens as mentioned in this paper, the magnetic moments of the Fe precipitates order ferromagnetically with a field of 328 KOe and are aligned parallel to the surface.
Abstract: By means of Conversion Electron Mossbauer Spectroscopy (CEMS) Fe clusters have been found on the surface of activated TiFe specimens. The magnetic moments of the Fe precipitates order ferromagnetically with a field of 328 KOe and are aligned parallel to the surface. The Fe precipitates are produced by the thermal treatment under hydrogen atmosphere and can be regarded as catalysts for the dissociation of the H2 molecules.
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TL;DR: The low temperature heat capacities and the hydrogen absorption properties of some ternary Haucke compounds were investigated to examine any correlation between the ability of these compounds to absorb hydrogen and their physical properties, e.g. their electronic structure and elastic properties as discussed by the authors.
Abstract: The low temperature heat capacities (1 – 20 K) and the hydrogen absorption properties of some ternary Haucke compounds — LaNi5−xAlx (0 ⩽ x ⩽ 1.5), LaNi5−xPtx (0 ⩽ x ⩽ 5) and La1−xThxNi5 (0 ⩽ x ⩽ 1)—were investigated to examine any correlation between the ability of these compounds to absorb hydrogen and their physical properties, e.g. their electronic structure and elastic properties. The density of states at the Fermi level has a minimum near x = 1 in LaNi5−xAlx. The electronic specific heat constants of LaNi5−xPtx decrease in a smooth fashion as the concentration of nickel decreases. La1−xThxNi5 alloys, however, only exhibit a slight change in their electronic specific heat constants. The low temperature heat capacities were also measured for the hydrides of these compounds. The electronic specific heat constant γ and the Debye temperature θD of the LaNi5−xAlxHy phase do not change as drastically, relative to the corresponding LaNi5−xAlx phase, as those for the RH2 compounds change relative to the corresponding pure metal R. This is probably caused by filling of the new bonding states formed in these compound hydrides with the added electrons of hydrogen.
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TL;DR: In this paper, current practices and future requirements for the storage, transmission and distribution of hydrogen are reviewed in order to identify inadequacies to be corrected before hydrogen can achieve its full potential as a substitute for fossil fuels.
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17 Jan 1980
TL;DR: In this article, a system for hydrogen storage including a hydridable material associated with an amount of inert material of high heat capacity was proposed to prevent, during hydriding, the temperature of the combined hydridables material-inert material from rising beyond that temperature at which the hydride of the hydridability material exhibits a hydrogen pressure equal to the partial pressure of hydrogen fed to the system.
Abstract: A system for hydrogen storage including a hydridable material associated with an amount of inert material of high heat capacity sufficient in amount to prevent, during hydriding, the temperature of the combined hydridable material-inert material from rising beyond that temperature at which the hydride of the hydridable material exhibits a hydrogen pressure equal to the partial pressure of hydrogen fed to the system. The system is insulated to inhibit heat transfer into or out of the system.
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29 Jan 1980TL;DR: A device for the storage of hydrogen, comprising a container, two porous plates opposed parallelly to each other across a fixed distance and fastened to the inner wall of the container, and an alloy capable of storing hydrogen placed in the spaces formed between the porous plates and the heating/cooling members, was described in this paper.
Abstract: A device for the storage of hydrogen, comprising a container, two porous plates opposed parallelly to each other across a fixed distance and fastened to the inner wall of the container, heating/cooling members disposed one each outside the porous plates and separated by a fixed distance from the corresponding porous plates, and an alloy capable of storing hydrogen placed in the spaces formed between the porous plates and the heating/cooling members
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TL;DR: In this paper, the dual function of heat and fuel storage in hydrides is described for application in cars as well as for stationary use, and it is shown that hydride can act as electrochemically reversible storage electrodes in alkaline accumulators and as a means for isotope separation.
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04 Sep 1980
TL;DR: In this paper, a hydrogen storage Ti-Fe alloy of the general formula was proposed, which is predominantly comprised of an effective alloy phase of CsCl type body-centered cubic crystals.
Abstract: A hydrogen storage Ti-Fe alloy of the general formula, Ti 1-x A x Fe y-z B z , in which A is Zr, Hf or a mixture thereof, B is a member selected from Cr, Cu, Co, Mo, V, Ni, Nb, Mn and a mixture thereof, and x, y and z are values of certain ranges, respectively. The alloy is predominantly comprised of an effective alloy phase of CsCl type body-centered cubic crystals. The alloy of the formula where z=O is within the scope of the invention. A process for making an alloy of this type is also disclosed.
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TL;DR: The intermetallic compounds LaNi5, FeTi and Mg2Ni are Pauli paramagnets with the susceptibilities 4.6, 3 to 4, and 0.9 × 10-6 emu/g, resp.
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12 Mar 1980
TL;DR: In this paper, a composite formed from large pieces of aggregate formed from (1) metal hydride (or Hydride-former) powder and (2) either metal powder or plastic powder or both is prepared.
Abstract: A composite formed from large pieces of aggregate formed from (1) metal hydride (or hydride-former) powder and (2) either metal powder or plastic powder or both is prepared. The composite has large macroscopic interconnected pores (much larger than the sizes of the powders which are used) and will have a very fast heat transfer rate and low windage loss. It will be useful, for example, in heat engines, hydrogen storage devices, and refrigerator components which depend for their utility upon both a fast rate of hydriding and dehydriding. Additionally, a method of preparing the composite and a method of increasing the rates of hydriding and dehydriding of metal hydrides are also given.
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TL;DR: In this article, a unifying concept for the poisoning process of hydride storage systems is proposed, which satisfactorily correlates many of the properties of transition metal, rare earth and actinide hydrides.
Abstract: Problems that can arise during the cycling steps for a hydride storage system usually involve events at surfaces. Chemisorption and reaction processes can be affected by small amounts of contaminants that may act as catalytic poisons. The nature of the poisoning process can vary greatly for the different metals and alloys that form hydrides. A unifying concept is offered, which satisfactorily correlates many of the properties of transition metal, rare earth and actinide hydrides.
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TL;DR: In this article, fresh surfaces of Mg2Cu polycrystals cleaved in UHV have been investigated by AES, XPS and X-ray induced AES at room temperature.
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24 Jul 1980TL;DR: In this article, hollow hole-free microspheres are stored in a chamber and hydrogen gas is diffused through the outer surface of the micro-spheres and delivered to an engine for use as a fuel.
Abstract: Hydrogen gas filled hollow hole-free microspheres are stored in a chamber. The microspheres are directed from the storage chamber to a heated chamber where the hydrogen gas is diffused through the outer surface of the microspheres and delivered to an engine for use as a fuel. After substantially all the hydrogen gas is removed, the microspheres are transported to another storage chamber from which they are completely removed for refilling with hydrogen gas while the first mentioned storage chamber is refilled with fueled microspheres.
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TL;DR: In this paper, the authors describe in detail the experiments on hydrogen maser wall shift and introduce briefly works on hydrogen masers in the Shanghai Bureau of Metrology in Shanghai, China.
Abstract: The principal accuracy limitation of a hydrogen maser is the uncertainty in the determination of the hydrogen maser wail shift. In this paper, we describe in detail the experiments on hydrogen maser wall shift and introduce briefly works on hydrogen masers in the Shanghai Bureau of Metrology. In experiments, we changed five different size storage bulbs by. turns. These bulbs were all coated in the same way with a locally made F4 coating. Results of the experiments are K(40°C) = -293 ± 17 mHzcm and a(40°C) = (-17 ± 2) × 10-30C-1. The unperturbed hyperfine frequency of the ground state of the hydrogen atomf0-0 was obtained by comparing five hydrogen masers to Loran C navigation system signals for one month. The average value in respect to TAI isf0-0 = 1420 405 751.768 ± 0.002 Hz. This value is closely in agreement with values of f0-0, which have been published by other authors since 1970.