Showing papers on "Hydrogen storage published in 1984"

Hermetically sealed metallic oxide-hydrogen battery using hydrogen storage alloy

Abstract: Disclosed is a hermetically sealed metalic oxide-hydrogen battery comprising a metallic oxide as a positive electrode active material and hydrogen as a negative electrode active material, characterized in that the negative electrode is composed of a hydrogen storage alloy represented by the formula: MNi.sub.5-(x+y) Mn.sub.x Al.sub.y wherein M is a mischmetal (Mm), a lanthanum element or a lanthanum-rich mischmetal (Lm); and x and y are values satisfying relations of 0

The properties of some zirconium-based gettering alloys for hydrogen isotope storage and purification☆

Abstract: Non-volatile getter alloys, which have been extensively used for a long time in the traditional field of vacuum technology, have recently been proposed for more advanced applications related to plasma physics, controlled nuclear fusion and general tritium-handling systems. Heat pumps and hydrogen storage devices, where pure hydrogen must be used, may also need purification systems based on these gettering alloys. Some zirconium-based alloys, which are commercially available with different compositions, are good candidates for getter materials in such applications. The equilibrium laws which govern the solution of the hydrogenic species in these alloys up to gas concentrations higher than those usually involved in vacuum applications have been investigated and are discussed together with the main physicochemical properties of the alloys.

Search for new metal-hydrogen systems for energy storage

Abstract: The heats of formation of the transition metal hydrides A5BHx A2BHx, ABHx, AB2Hx and AB5Hx (A ≡ Sc, Ti, V, Y, Zr, Nb, La, Hf, Ta, Ni, Pd; B ≡ transition metal) are calculated by means of a semiempirical model based on the electronic structure of the host alloy. Out of the 1380 possible compounds A5B, A2B and AB, only 44 are predicted by the model to react with hydrogen with a heat of formation between −12 and −25 kJ. Approximately half of these potential hydrogen storage systems have already been investigated.

Fuel tank for hydrogen vehicle and fuel supplying system

Abstract: A fuel tank for a hydrogen vehicle in which a plurality of fuel cylinders are disposed and contained in a casing of the fuel tank for containing hydrogen storage alloy, the fuel cylinders are connected to a header mounted integrally with the casing for containing the fuel cylinders, a conduit for supplying engine exhaust gas is connected to the casing for externally heating the fuel cylinders in the casing. Further, a fuel supplying system which comprises supplying hydrogen gas from a fuel supply conduit connected to a header mounted integrally with the fuel tank, supplying the hydrogen gas from the openings of a plurality of fuel cylinders into the inner cylinder sections of the fuel cylinders to allow the hydrogen gas to be absorbed to hydrogen storage alloy of the respective fuel cylinders, supplying air or water from an engine exhaust gas passage of a fuel tank casing into the casing in case of supplying the hydrogen while cooling the fuel cylinders from the exterior, closing the fuel supply conduit of the header after filling the hydrogen gas of a predetermined amount, and then supplying the exhaust gas through the engine exhaust gas passage to externally heat the fuel cylinders in case of desorbing the hydrogen gas in the fuel tank. Thus, the fuel tank can desorb or absorb hydrogen under a relatively low pressure and can store the hydrogen in the amount corresponding to the running distance of a gasoline vehicle in a compact structure.

Preparation and hydriding behavior of magnesium metal clusters formed in low-temperature cocondensation: application of magnesium for hydrogen storage

Abstract: Le magnesium absorbe de grandes quantites d'hydrogene dans des conditions plus douces (p H2 =460 Torr, T=200-250°C) lorsqu'il a ete transforme en petites particules solvatees dans du THF, formees par co-condensation des atomes de Mg avec des molecules de THF, a −196°C

The effects of aluminium substitution in TiFe on its hydrogen absorption properties

Abstract: The influence of the partial substitution of iron by aluminium in TiFe on the hydrogen absorption properties was systematically investigated. The pressure-composition isotherms were determined to establish differences in the thermodynamic properties. When aluminium was added to the TiFe compound, the hydrogen storage capacity decreased markedly and the γ phase was not formed. The plateau pressure was sloping and was higher for TiFe0.98Al0.02 and TiFe0.96Al0.04 and lower for TiFe0.94Al0.06 and TiFe0.90Al0.10 than for pure TiFe. These results are explained by the difference between the number of valence electrons present in aluminium and iron. The ΔHo, ΔSo and ΔGo values were obtained from plots of In Pversus 1 T using the van't Hoff relation. The hysteresis energy loss decreased with increasing aluminium content.

The electronic structure of hydrogenated intermetallic compounds: Theory

Abstract: We discuss the results of a theoretical investigation of the electronic properties of some intermetallic hydrogen storage compounds such as FeTiH, FeTiH 2 and Mg 2 NiH 4 . The metal-hydrogen and H-H interactions, which in all cases result in a low energy structure in the density of states, are analysed by means of a partial wave decomposition within the framework of the augmented plane wave method; this allows us both to gain insight into the preferential interactions of hydrogen with each of the two metal components and to predict the main features of the corresponding X-ray emission spectra. We discuss the change in the general position of the Fermi level in the metal d bands which occurs on hydrogenation of FeTi. The theoretical results are used to interpret successfully some experimental data for the electronic specific heat, the magnetic susceptibility and the Mossbauer isomer shifts. We found that cubic Mg 2 NiH 4 is a semiconductor, unlike the hydrides of FeTi which are metallic. This is due to complete filling of the four low energy metal-hydrogen-induced bands and the narrow nickel d bands. The consequences of these results on the hydrogen absorption capacity of intermetallic compounds of the same family are discussed.

Effect of sulphur addition on the properties of FeTi alloy for hydrogen storage

Abstract: Addition of sulphur to the Fe-Ti alloy was found to produce a marked improvement in the properties of the alloy for hydrogen storage The most effective composition was FeTi105S002, which had a low activation temperature (80–100 °C), a short incubation time (10–30 h) and a good equilibrium plateau pressure over a wide concentration range of absorbed hydrogen The degree of pulverization for this alloy after the absorption-desorption cycle test was comparatively moderate The sulphur added to the alloy was converted into Ti2S which was precipitated in a network structure with strips about 5 μm wide separated by spaces of dimensions about 20–50 μm

Thermodynamics and kinetics of Zr(Fe1−xMnx)2Hx and the storage compound Ti0.8Zr0.2MnCrH3

Abstract: Thermodynamic and kinetic data for hydrogen absorption in Zr(Fe1−xMnx)2 and Ti0.8Zr0.2CrMn, which is one of the most promising hydrogen storage materials, are presented. The data were obtained from measurements performed using a high pressure microbalance. The macroscopic rate constants obey an Arrhenius law, and comparison with the hydrogen self-diffusion coefficient of Ti0.8Zr0.2MnCrH3 recently measured by Hempelmann and coworkers suggests that the rate-limiting step in the absorption kinetics is the α-β phase transition rather than the comparatively fast hydrogen diffusion in the bulk.

Hydrogen Fuel for Underground Mining Machinery

Abstract: A hydrogen engine-fuel system is being developed as an alternative for powering underground mining machinery. A diesel was converted to a spark-ignited hydrogen engine and operated with a metal hydride, solid-state hydrogen storage system. Performance and emissions data show that hydrogen can be used as an ultralow emission fuel for underground mining. A special method of fuel control has overcome abnormal combustion problems frequently experienced with hydrogen fuel. The turbocharged, aftercooled engine maintains NO /SUB x/ emissions (the only significant pollutant) below 0.7 gram per kilowatt-hour. Power and fuel consumption are comparable to the naturally aspirated, prechambered diesel version of the engine. Hydrogen fuel is released from a metal hydride storage container by heat from the engine coolant. Through proper design, hydride containment can limit the leakage of hydrogen, in a worst-case accident, to acceptable levels.

Dynamic behaviour of simple hydride bed devices

Abstract: Dynamic hydriding and dehydriding tests were performed on heat-transfer-enhanced hydride modules containing the hydrogen storage materials LaNi5, LaNi4.7Al0.3 and MmNi4.5Al0.5 (Mm ≡; misch metal). The hydrogen pressure was determined as a function of the hydrogen content of the beds for various hydrogen flow rates with the water inlet temperature and the water flow rate kept constant. Owing to pressure gradients within the modules and the limited heat transfer to and from the storage material, these curves show increasing hysteresis if the hydrogen flow rate increases. The dependence of the hydrogen pressure on the water inlet temperature Ti could be extracted from the pressure-composition curves of the single storage units by varying the inlet water temperatures at constant hydrogen flow rates. It was found that the operating characteristics of dual hydride bed devices can be estimated more realistically by a combination of such graphs than by using the van't Hoff plots determined under static test conditions. This is demonstrated for the LaNi4.7Al0.3-LaNi5 and LaNi4.7Al0.3-MmNi4.5Al0.5 systems which were tested for their applicability in metal hydride heat pumps.

Hydrogen storage system

Abstract: A metal composition, particularly magnesium or a magnesium alloy is activated for hydrogen storage by a plurality of activation cycles each comprising a step of hydriding the metal composition followed by a dehydriding step; in this way the metal composition is activated for reaction with hydrogen for hydrogen storage, more efficiently and in less time than with prior techniques.

Hydrogen storage materials of zirconium-chromium-iron and titanium alloys characterized by ZrCr2 stoichiometry

Abstract: An alloy consisting of zirconium, chromium, iron and optionally titanium is characterized in having C14 hexagonal crystal structure and ZrCr2 stoichiometry. Members of a preferred class of compounds, represented by the empirical formula Zr1-x Tix Cr2-y Fey wherein "x" has a value between 0.0 and 0.9 and "y" has a value of 0.1 to 1.5, are particularly suitable for use as hydrogen storage materials.

Manufacture of hydrogen storage electrode

Abstract: PURPOSE:To form a hydrogen storage electrode by mixing an additive, which generates hydrogen by reacting with solution, into a hydrogen storage alloy and steeping the mixture into solution and activating the hydrogen storage alloy with generated hydrogen, and thereafter forming the mixture into an electrode shape. CONSTITUTION:An additive is made of aluminum or nickel or raney alloy etc., which generates hydrogen by dissolving by itself in alkaline solution etc., and is mixed into a hydrogen storage alloy composed of an alloy which is made of both elements, one combines easily with hydrogen such element as Ca etc. and the other is difficult to combine with hydrogen such element as Al etc., and a mixture is steeped into alkaline solution and stirred so as to hydrogenate and activate the hydrogen storage alloy with generated hydrogen and the mixture is washed and a binding agent such materials as polyethylene etc. is added thereto and said mixture is formed by compressing into bunching metal or foaming metal etc. which is a collector material, and is foamed into a hydrogen occulusion electrode which makes a negative electrode of an alkaline storage battery. Therefore, an electrode with good characteristics can be obtained by simple method.

Hydrogen storage vessel

Abstract: PROBLEM TO BE SOLVED: To facilitate the handling of a hydrogen storage vessel by providing a connection means which is changed over from an open condition to a closed condition when a hydrogen filling source is disconnected and providing a check valve which prevents the back flow of gas from a supply source to the vessel in which hydrogen absorbing alloy is stored. SOLUTION: A hydrogen storage vessel used in a fuel battery system stores hydrogen absorbing alloy 2 in a metallic vessel 1 provided with pipe connection parts 5, 6 and has a filter 3 which prevents the flowing out of the hydrogen absorbing alloy 2 from the pipe connection part 6. At this time, the pipe connection part on inlet side 5 is connected with a filling source which fills hydrogen into the hydrogen storage vessel and incorporates a valve mechanism which is changed over from an open condition to a closed condition when it is disconnected from the filling source. On the other hand, the pipe connection part on outlet side 6 is connected with a system side which supplies hydrogen filled in the hydrogen storage vessel. Moreover, it is possible to prevent the back flow of gas from the system side into the hydrogen storage vessel by a check valve 7 provided between the pipe connection part on outlet side 6 and a filter part 3.

Metal hydrides for hydrogen storage

Abstract: Classification des hydrures, structures cristallines, thermodynamique. Applications pratiques. Alliages a base de Mg, de Ti, de lanthanides (en particulier mischmetal) pour le stockage de l'hydrogene

Method for releasing stored hydrogen gas

Abstract: PURPOSE: To release stored hydrogen gas efficiently, with reduced heat quantity of the external heat source, by storing the heat generated in the occlusion of hydrogen in a hydrogen occlusion alloy temporarily in a heat storage vessel, and releasing the hydrogen by the combined use of the stored heat and the heat of the external assistant heat source. CONSTITUTION: The valve 8 connected to the hydrogen storage vessel 1 filled with granular hydrogen occlusion alloy 2 is closed, the valve 7 is opened to evacuate the hydrogen storage vessel 1, and hydrogen gas is introduced into the hydrogen storage vessel 1 through the filter 9 to effect the occlusion of the hydrogen gas in the hydrogen occlusion alloy 2. The heat of occlusion generated by this process is stored in the heat medium 15 in the heat storage vessel 11 by circulating the heat medium in the pipe 4 by the aid of the heat exchanger 10 in the hydrogen storage vessel 1 and the heat exchanger 12 in the heat storage vessel 11. The occluded hydrogen can be released by closing the valve 7, opening the valve 8, heating the heat medium 15 with electrical heater 17 connected to the electrical source 18, circulating the heat transferred from the external heat source and the heat stored in the heat medium by the pump 13, and using the heat for the heating of the hydrogen occlusion alloy 2. COPYRIGHT: (C)1985,JPO&Japio

Hydrogen storage material

Abstract: A hydrogen storage material for releasably storing hydrogen having a microstructure containing an alloy phase of the general formula R 2 Fe 17 , wherein R is cerium and lanthanum and, optionally, at least one other rare earth element, and wherein a microstructure also contains from about 2 to 35% by weight, based on the total weight of all phases, of a eutectic of the formula R'/R'Fe 2 , wherein R' is lanthanum-starved R; the alloy phase of the general formula R 2 Fe 17 being present in an amount of not less than 40% by weight of the material, and the material contains less than 60% by weight of cerium based on the total amount of cerium, lanthanum and, if present, at least one other rare earth element. A method for producing such material by heat treating in an inert atmosphere so as to homogenize same and to increase the proportion of alloy phase in the material is also described.

Hydrogen storage apparatus

Abstract: PURPOSE:To obtain a hydrogen storage apparatus for supplying conveniently hydrogen with a simple constitution apparatus by housing a hermetic vessel filled with metallic hydride in a heat medium tank provided in a case, and providing a connector communicating with the hermetic vessel. CONSTITUTION:A heat medium tank 16 having an open side is provided in a case 17, and a single or plural hermetic vessel 1 filled with metallic hydride is housed in the heat medium tank 16. A single or plural connectors 7 communicating with the hermetic vessels 1 are provided to obtain the desired hydrogen storage apparatus. To use the apparatus for occluding hydrogen in metallic hydride, a low-temp. cooling heat medium such as water as a heat medium is supplied into the heat medium tank 16 to cool the metallic hydride in the hermetic vessel 1, and hydrogen is supplied into the hermetic vessel 1 from a hydrogen bomb 11. Thus the heat generated in occluding hydrogen is absorbed. When hydrogen is released, water is drained from the heat medium tank 16, and hot air is introduced to heat the hermetic vessel 1.

Hydrogen sorption by the hyperstoichiometric cerium-nickel-copper (Ce1+xNi2.5Cu2.5) alloys

Abstract: Hydrogenation characteristics of the Ce/sub 1+x/Ni/sub 2.5/Cu/sub 2.5/ alloys with x = 0.1-0.2 were studied as a function of temperature (0-100/sup 0/C) and hydrogen dissociation pressure (0.05-50 atm). Hyperstoichiometric Ce up to approximately 10% appears to substitute for the Ni and/or Cu, whereas additional excess Ce generates an extraneous phase. CeNi/sub 5/ which otherwise does not absorb hydrogen becomes an excellent hydrogen storage material in the presence of 10% excess Ce and 50% Ni replaced by Cu. The hydrogen capacity of this Ce/sub 1.1/Ni/sub 2.5/Cu/sub 2.5/ alloy is quite high, e.g., approx.5.3H/formula unit (fu), and the vapor pressure of its hydride is approx.4 atm at 22/sup 0/C. The mean enthalpy and entropy of dehydrogenation for the Ce/sub 1.1/Ni/sub 2.5/Cu/sub 2.5/ alloy are 20.6 kJ/(mol of H/sub 2/) and 80.5J/(mol K), respectively. These values are lower than those for the conventional hydrogen storage materials. The kinetics of hydrogen sorption for the Ce/sub 1+x/Ni/sub 2.5/Cu/sub 2.5/ alloys are extremely fast. 3 figures, 2 tables