Showing papers on "Hydrogen storage published in 1988"

Hydrogen as an energy carrier : technologies, systems, economy

Abstract: Hydrogen as an Energy Carrier - A Guide.- A: Significance and Use of Hydrogen.- 1. Energy Supply Structures and the Importance of Gaseous Energy Carriers.- 1.1 Energy Demand Structures.- 1.2 The World Energy Consumption.- 1.3 The Energy User Structure and its Influence on Energy Usage.- 1.4 Energy Resources and their Range.- 1.5 Requirements on Future Energy Systems.- 2. Technologies for the Energetic Use of Hydrogen.- 2.1 Combustion of Hydrogen.- 2.2 Fuel Cells.- 2.3 Stationary Systems for Hydrogen.- 2.4 Hydrogen as a Fuel.- 3. Hydrogen as Raw Material.- 3.1 Present Situation and Future Development.- 3.2 Non-energetic Use in the Chemical Industry.- 3.3 Indirect-energetic Use of Hydrogen.- 3.4 Non-fossil Hydrogen as a Raw Material.- 4. Safety Aspects of Hydrogen Energy.- 4.1 Introduction.- 4.2 Safety Specific Properties and Characteristics.- 4.3 Behaviour in the Case of Deflagration and Detonation.- 4.4 Summary.- B: Production of Hydrogen from Nonfossil Primary Energy.- 5. Photovoltaic Electricity Generation.- 5.1 Physical Mechanism.- 5.2 Technology of Solar Cell Production.- 5.3 Solar Cell Moduls and Generators.- 5.4 Present Status of Photovoltaic Technology.- 5.5 Goals and Future Developments.- 6. Thermo-mechanical Electricity Generation.- 6.1 Thermodynamics of Solarthermal Energy Conversion.- 6.2 Production of High Temperature Heat by Means of Solar Energy.- 6.3 Production of Heat by Means of Nuclear Energy.- 6.4 Thermodynamic Cycles for Electricity Generation.- 6.5 Mechanical Energy Conversion for Electricity Generation.- 6.6 Indirect Possibilities of Solar Energy Utilization.- 6.7 Possibilities for Hydrogen Production.- 7. Water Splitting Methods.- 7.1 Survey.- 7.2 Thermodynamics of Water Splitting.- 7.3 Energy Balance of Chemo-technical Processes.- 7.4 Conventional Processes of Water Splitting with Hydrocarbons or Coal as Primary Energy Source.- 7.5 Water Splitting by Electrolysis.- 7.6 Water Splitting by Thermochemical Cycles.- 7.7 Economic Comparison of Different Water Splitting Methods.- 7.8 Further Methods of Water Splitting.- 8. Selected Hydrogen Production Systems.- 8.1 Survey and Selection of Systems.- 8.2 Technology and Electrolyser Plants.- 8.3 Electrolysis and Hydropower.- 8.4 Electrolysis and Nuclear Power.- 8.5 Electrolysis and Solar Thermal Power.- 8.6 Electrolysis and Wind Power.- 8.7 Electrolysis and Photovoltaic Power.- 9. Storage, Transport and Distribution of Hydrogen.- 9.1 Introduction.- 9.2 Storage Types and Storage Methods.- 9.3 Large Hydrogen Storage.- 9.4 Long-distance Hydrogen Transport.- 9.5 Short-distance Transport and Distribution.- 9.6 End-user Hydrogen Storage.- C: Design of a Future Hydrogen Energy Economy.- 10. Potential and Chances of Hydrogen.- 10.1 Future Contribution of Hydrogen.- 10.2 Sites for Hydrogen Production from Unlimited Energy Sources.- 11. Hydrogen in a Future Energy Economy.- 11.1 Hydrogen Production with Large Solar- and Wind-Stations.- 11.2 Development Strategy and Expenditures for the Production of Large Amounts of Hydrogen.- 11.3 Long-distance Transport Systems.- 11.4 Nuclear Energy and the Production of Large Amounts of Hydrogen.- 11.5 Characteristics of an Energy System with a Large Hydrogen Share.- 12. Concepts for the Introduction of Nonfossil Hydrogen.- 12.1 Introduction into Industrialized Countries.- 12.2 Decentralized Use of Hydrogen in Southern Countries.- 13. Energy-economic Conditions and the Cooperation with Hydrogen Producing Countries.- 13.1 Capital Requirements.- 13.2 Funding Possibilities.- 13.3 Cooperation with Hydrogen Producing Countries.- 13.4 Steps to Solar Hydrogen.

Amorphous metal alloy compositions for reversible hydrogen storage and electrodes made therefrom

Abstract: The present invention provides a novel amorphous metal alloy composition which reversibly stores hydrogen and is useful as the hydrogen storage electrode in an energy storage device. The amorphous metal alloy is made up of at least three elements with at least one element of Ag, Hg, or Pt; at least one element of Pb, Cu, Cr, Mo, W, Ni, Al, Co, Fe, Zn, Cd, Ru or Mn: and at least one element of Ca, Mg, Ti, Zr, Hf, Nb, V or Ta.

Hydrogen storage characteristics of mechanically alloyed amorphous metals

Abstract: The hydrogen storage properties of a series of mechanically alloyed (MA) amorphous Ni1xZrx alloys are studied, using both gas phase and electrochemical techniques, and are compared to H storage of rapidly quenched (RQ) amorphous Ni1−xZrx. In the MA alloys, hydrogen resides in the Ni4−nZrn (n = 4,3,2) tetrahedral interstitial sites, with a maximum hydrogen-to-metal ratio of 1.9(4 n)xn(1 − x)4 − n. These features are identical to those of the RQ alloys and indicate that the topological and chemical order of the MA and RQ materials are essentially the same. However, the typical binding energy of hydrogen in a Ni4−nZrn site, En, is shifted in the MA alloys relative to the RQ alloys and the distribution of binding energies centered on En is significantly broader in the MA samples. Thus, the MA and RQ alloys are not identical and sample annealing does not alter this subtle distinction. The sensitivity of H storage to the presence of chemical order in binary alloys are analyzed theoretically and the data are found to be most consistent with little or no chemical order (random alloys).

Extended life nickel-hydrogen storage cell

Abstract: A nickel-hydrogen electrical storage cell (10) contains a nickel positive electrode (14), a hydrogen negative electrode (16), a separator (18) between the electrodes (14 and 16), and electrolyte including a rubidium hydroxide and cesium hydroxide, and a pressure vessel to contain these elements. The cell (10) is expected to operate for extended cycle life in deep discharge conditions based upon extrapolations of accelerated life testing results. The electrolyte may be essentially entirely rubidium hydroxide or cesium hydroxide, a mixture of the two, or a mixture with another component. This type of storage cell is useful in spacecraft applications.

Hydrogen Storage Characteristics of FeTi Containing Zirconium

Abstract: Effet de l'addition de zirconium (1 a 15% at.) au compose intermetallique FeTi sur le processus d'hydruration initial, sur les isothermes pression-composition et sur la microstructure

Hydride reactor apparatus for hydrogen comminution of metal hydride hydrogen storage material

Abstract: Apparatus for the hydride-dehydride cycling comminution of metal hydride, hydrogen storage alloy materials, which comminuted hydrogen storage alloy material is adapted for use in the negative electrode of hydrogen storage, electrochemical cells.

Method for the continuous fabrication of hydrogen storage alloy negative electrodes

Abstract: OF THE DISCLOSURE An improved method for the continuous fabrication of metal-hydride, electrochemical, hydrogen storage alloy, negative electrodes for use in rechargeable nickel metal hydride cells. The improved method comprises the steps of providing measured amounts of powdered metal hydride electrochemical hydrogen storage alloy material and disposing said material upon a continuous wire mesh screen substrate. Thereafter, the powdered metal hydride electrochemical hydrogen storage alloy and wire mesh screen are subjected to a compaction process wherein they are rolled and pressed so as to form a single integral electrode web which is subsequently exposed to a high temperature sintering process in a chemically inert environment. The sintering process is designed to drive off excess moisture in the material while discouraging oxidation of the electrode web and set the electrode web state of charge. 0149r

Intrinsic degradation of FeTi by thermally induced hydrogen absorption-desorption cycling

Abstract: The deterioration of the hydrogenation properties of FeTi during thermally induced hydrogen absorption-desorption cycling was investigated using the following: 1. (i) the change in the P-C-T curves as a function of the number of cycles, 2. (ii) X-ray diffraction, and 3. (iii) the thermal desorption of hydrogen after cycling. The results of the thermal desorption of hydrogen provide information about the hydrogen occupation at various interstitial sites, which are distinguished by different binding energies. It was found that the formation of stable hydrides is the source of degradation caused by thermally induced hydrogen absorption-desorption cycling. Thermal cycling of FeTi produces an intrinsic degradation that reduces the hydrogen storage capacity and suppresses the formation of the γ phase in its hydride. Surprisingly, as a result of degradation, the overall rate of the hydrogenation reaction is also decreased. The mechanism of the degradation is probably related to the formation of stable hydrides, which causes a change in the environments of the sites occupied by hydrogen in the neighbour matrix. Most of the properties can be recovered by a simple annealing treatment in vacuum.

Fuel cell power generating system

Abstract: PURPOSE:To increase the conversion efficiency of fuel gas generated in fuel processing equipment into electric power and to effectively follow quick load variation by incorporating hydrogen storage equipment utilizing a hydrogen storage alloy in a fuel cell power generating system. CONSTITUTION:Hydrogen storage equipment utilizing a hydrogen storage alloy is incorporated in a fuel cell power generating system. unreacted gas of fuel gas generated in fuel processing equipment 3 and supplied to a negative gas chamber and excess fuel gas bypassing the fuel cell are converted into pure hydrogen and the hydrogen is absorbed and stored in a hydrogen storage alloy. The hydrogen released from hydrogen storage alloy is supplied to the fuel cell. The surplus or lack of fuel gas attendant on load variation is compensated by absorption into or desorbed from the hydrogen storage alloy. The fuel cell can cope with quick load increase, and since the unreacted gas in exhaust fuel gas can be converted into electric power, the gas produced in the fuel processing equipment 3 is almost completely utilized. Thereby, the load response capability and fuel efficiency of the power generating system are increased.

Hydrogen storage alloy electrode and manufacture thereof

Abstract: PURPOSE: To lower hydrogen balance pressure in a high temperature condition (for example, approximately 80°C) and improve discharge characteristics without any loss of high capacity at that process by reducing a nickel amount in a Zr-Mn-V-Mo-Cr-Ni hydrogen storage alloy composition. CONSTITUTION: This electrode is composed of a hydrogen storage alloy or the hydrogen compound thereof expressed by a general formula of ZrMn w Mo x Cr y Ni z , where 0.5

Protection of FeTi thin films using palladium coatings

Abstract: The use of FeTi as a hydrogen storage material is hindered by surface decomposition of the alloy when exposed to hydrogen charging gases containing PPM levels of O2/H2O impurities. This study investigates the application of palladium coatings as barrier materials against these impurities in order to increase the effective lifetime of the alloy over numerous charge-discharge cycles. Palladium was chosen because it has excellent hydrogen transport properties and it is impermeable to impurities containing oxygen at the temperatures and pressures of interest. Two 10 nm FeTi thin-film specimens were prepared, one coated with an additional 5 nm Pd overlayer, and both samples exposed to identical annealing and reduction treatments. Conversion electron Mossbauer spectroscopy (CEMS) was used along with other analytical techniques (i.e. XPS and SIMS) to obtain chemical, magnetic and electronic information at the buried and exposed interfaces. CEMS demonstrated that the Pd coating prevented subsurface decomposition of FeTi.

Hydrogen storage alloy electrode and method for preparing the same

Abstract: Disclosed is a hydrogen storage alloy electrode prepared by integrating a mixture of a hydrogen storage alloy powder, an electrical conducting powder and a polymer binder with a current collector, characterized in that the polymer binder is composed of a polyacrylic acid salt and polytetrafluoroethylene as essential components, and that the hydrogen storage alloy powder is coated with polyacrylic acid salt, wherein the three-dimensional reticulate molecular chain of the polyacrylic acid salt itself is partially severed. Disclosed also is a method of preparing a hydrogen storage alloy electrode which comprises the steps of preparing a paste of a mixture containing hydrogen storage alloy powder, electrical conducting powder and a polymer binder, coating a current collector with the paste, drying it and pressure molding the current collector coated with the paste, the method being characterized in that at least a polyacrylic acid salt and polytetrafluoroethylene are used as the polymer binder, and after the paste is stirred at a high speed, the current collector is coated with the paste.

Manufacture of hydrogen storage electrode

Abstract: PURPOSE:To increase the capacity and the life by forming a porous conductive layer on the surface of a paste type hydrogen storage electrode. CONSTITUTION:MmNi9.8Co0.5Mn0.4A10.5 alloy prepared with an argon arc furnace is heat-treated with a vacuum thermal treatment furnace, and crushed to 400 mesh or less. The hydrogen storage alloy powder is mixed with ethylene glycol solution containing 5 wt.% polyvinyl alcohol, 0.8 wt.% polyethylene fine powder, and 0.5 wt.% vinyl chlorideacrylonitrile copolymer short fiber to form paste. The paste is applied to a 0.15mm thick nickel plated steel punched metal having a pore diameter of 1.8mm and an opening rate of 50%. The coated punched metal is passed through a slit having a width of 0.6mm to smooth it, and dried at 120 deg.C for one hour to obtain a hydrogen storage electrode. After pressing, a porous conductive layer is formed on the electrode by various methods such as electroless copper plating, electric copper plating, neckel powder coating, palladium deposition, and nickel vapor deposition. The conductivity of the electrode is increased, and the mechanical strength, the capacity, and the life are also increased.

Hydrogen storage alloy electrode and its manufacture

Abstract: PURPOSE: To increase the quantity of hydrogen storage alloy and to make the mass production of an electrode possible by stirring hydrogen storage alloy powder together with polyacrylate and polytetrafluoroethylene at high speed to form paste, and applying the paste to a current collector to form a hydrogen storage alloy electrode CONSTITUTION: A mixture of hydrogen storage alloy powder, conductive material powder, and a polymer binder is applied to a current collector to manufacture a hydrogen storage alloy electrode By using polyacrylate such as sodium polyacrylate and, for example, the dispersion of polytetrafluoroethylene as the polymer binder, the binding capability is retained and a large volume of hydrogen is absorbed Since the surface of a hydrogen storage alloy particle is covered with polyacrylate by speed stirring, oxidation of the alloy particle is prevented This production process is simple and makes continuous job possible, and is suitable for mass production COPYRIGHT: (C)1989,JPO&Japio

Bridged transition-metal complexes and uses thereof for hydrogen separation, storage and hydrogenation

Abstract: The present invention constitutes a class of organometallic complexes which reversibly react with hydrogen to form dihydrides and processes by which these compounds can be utilized. The class includes bimetallic complexes in which two cyclopentadienyl rings are bridged together and also separately pi-bonded to two transition metal atoms. The transition metals are believed to bond with the hydrogen in forming the dihydride. Transition metals such as Fe, Mn or Co may be employed in the complexes although Cr constitutes the preferred metal. A multiple number of ancillary ligands such as CO are bonded to the metal atoms in the complexes. Alkyl groups and the like may be substituted on the cyclopentadienyl rings. These organometallic compounds may be used in absorption/desorption systems and in facilitated transport membrane systems for storing and separating out H2 from mixed gas streams such as the product gas from coal gasification processes.

Method of forming amorphous metal alloy compositions for reversible hydrogen storage

Abstract: Novel materials having the ability to reversibly store hydrogen are amorphous metal alloys of the formula A.sub.a M.sub.b M'.sub.c wherein A is at least one metal selected from the group consisting of Ag, Au, Hg, Pd and Pt; M is at least one metal selected from the group consisting of Pb, Ru, Cu, Cr, Mo, Si, W, Ni, Al, Sn, Co, Fe, Zn, Cd, Ga and Mn; and M' is at least one metal selected from the group consisting of Ca, Mg, Ti, Y, Zr, Hf, Nb, V, Ta and the rare earths; and wherein a ranges from greater than zero to about 0.80; b ranges from zero to about 0.70; and c ranges from about 0.08 to about 0.95; characterized in that (1) a substantial portion of A is disposed on the surface of said material and/or (2) that said material functions as an active surface layer for adsorbing/desorbing hydrogen in conjunction with a bulk storage material comprising a reversible hydrogen storage material.

Hydrogen storage apparatus and method for detecting quantity of stored hydrogen in hydrogen storage apparatus

Abstract: PURPOSE:To obtain a hydrogen storage apparatus by which the quantity of stored hydrogen can be known easily by filling a receptacle with at least two or more kinds of hydrogen storage alloys different in hydrogen equilibrium at a certain fixed temperature CONSTITUTION:In case of combining two or more kinds of hydrogen storage alloys different in hydrogen equilibrium, an alloy for occluding hydrogen and an alloy for detecting the quantity of hydrogen are respectively provided in a small quantity and a large quantity The temperature-equilibrium pressure characteristic as well as the hydrogen storage capacity depends on the composition, combination and the quantity of alloys of hydrogen storage alloys used Accordingly it is necessary to previously measure the capacity of a storage apparatus and the temperature-equilibrium pressure characteristic of alloy to be charged according to the estimated used conditions prior to a practical use At the time of occluding hydrogen, the hydrogen pressure is measured by a pressure gauge, and the measured value is compared with an occlusion characteristic curve (a) to know the quantity of stored hydrogen At the time of discharging hydrogen, the residual quantity of hydrogen can be known by using a discharge characteristic curve (b)

Hydrogen storage materials

Abstract: Coverage includes: hydrides; metal hydride systems; intermetallic hydrides; and chemical heat pumps.

Hydrogen storage materials useful for heat pump applications

Abstract: Disclosed is a class of multicomponent, high capacity hydrogen storage materials suitable for use in a heat pump comprising titanium, vanadium, manganese and iron. The hydrogen storage materials are disordered, multiphase, polycrystalline materials which are predominately vanadium and comprise at least a major crystalline phase substantially surrounded by an intergranular phase, with one or more inclusion phases. The materials are characterized by a Bragg x-ray diffraction pattern with a major peak occurring 43 degrees 2 theta. Also disclosed are processes for making the class of materials and a heat pump system utilizing at least one such material.

Hydrogen storage electrode

Abstract: A C15 type alloy hydrogen storage electrode is described which comprises a body of an alloy of the general formula ZrfVgNihMi, wherein f, g, h and i are atomic ratios of Zr, V, Ni and M and M is at least one element selected from Mg, Ca, Y, Hf, Nb, Ta, Cr, Mo, W, Mn, Fe, Co, Pd, Cu, Ag, Au, Zn, Cd, Al, Si, In, Sn, Bi, La, Ce, Pr, Nd, Th, Sm and Mm, wherein Mm is a mixture of rare earth elements.

Combined battery/hydrogen storage for autonomous wind/solar systems

Abstract: We have analyzed total wind/solar electrical energy systems using time step simulation. The systems investigated here are a combination of the following components: - Photovoltaic array (PV) - Wind energy converter (WEC) - Pb batteries - Hydrogen storage system, consisting of electrolyser, H 2 /O 2 storages and fuel cell. The investigations are focussed on: - the determination of system configurations yielding renewable fractions of 1 (autonomous systems) - the analysis of the influence of the hydrogen systems cycle efficiency on the storage configuration - the system optimization with respect to energy investment.

A fuel cell energy storage system for Space Station extravehicular activity

Abstract: The development of a fuel cell energy storage system for the Space Station Extravehicular Mobility Unit (EMU) is discussed. The ion-exchange membrane fuel cell uses hydrogen stored as a metal hydride. Several features of the hydrogen-oxygen fuel cell are examined, including its construction, hydrogen storage, hydride recharge, water heat, water removal, and operational parameters.

Calculation of enthalpy of metal hydride formation and prediction of hydrogen site occupancy

Abstract: A model is presented for calculating the enthalpy of formation of metal hydrides. The model takes into account the effect of the bond number formed between the hydrogen and metal atoms. Site occupancies of hydrogen atoms in pure metals calculated using this model are in good agreement with experimental observations. A method for calculating the binding energy of hydrogen atoms at different sites in hydrogen storage alloys is also presented, and is shown to predict accurately the site occupancy of hydrogen atoms in CI5 Laves phase alloys.MST/7I9