WorldWideScience

Sample records for high temperature hydrogen

  1. Hydrogen Production from Nuclear Energy via High Temperature Electrolysis

    International Nuclear Information System (INIS)

    James E. O'Brien; Carl M. Stoots; J. Stephen Herring; Grant L. Hawkes

    2006-01-01

    This paper presents the technical case for high-temperature nuclear hydrogen production. A general thermodynamic analysis of hydrogen production based on high-temperature thermal water splitting processes is presented. Specific details of hydrogen production based on high-temperature electrolysis are also provided, including results of recent experiments performed at the Idaho National Laboratory. Based on these results, high-temperature electrolysis appears to be a promising technology for efficient large-scale hydrogen production

  2. Metallic Membranes for High Temperature Hydrogen Separation

    DEFF Research Database (Denmark)

    Ma, Y.H.; Catalano, Jacopo; Guazzone, Federico

    2013-01-01

    membrane fabrication methods have matured over the last decades, and the deposition of very thin films (1–5 µm) of Pd over porous ceramics or modified porous metal supports is quite common. The H2 permeances and the selectivities achieved at 400–500 °C were in the order of 50–100 Nm3/m/h/bar0.5 and greater......Composite palladium membranes have extensively been studied in laboratories and, more recently, in small pilot industrial applications for the high temperature separation of hydrogen from reactant mixtures such as water-gas shift (WGS) reaction or methane steam reforming (MSR). Composite Pd...... than 1000, respectively. This chapter describes in detail composite Pd-based membrane preparation methods, which consist of the grading of the support and the deposition of the dense metal layer, their performances, and their applications in catalytic membrane reactors (CMRs) at high temperatures (400...

  3. Ceramic membranes for high temperature hydrogen separation

    Energy Technology Data Exchange (ETDEWEB)

    Fain, D.E.; Roettger, G.E. [Oak Ridge K-25 Site, TN (United States)

    1996-08-01

    Ceramic gas separation membranes can provide very high separation factors if the pore size is sufficiently small to separate gas molecules by molecular sieving and if oversized pores are adequately limited. Ceramic membranes typically have some pores that are substantially larger than the mean pore size and that should be regarded as defects. To assess the effects of such defects on the performance of ceramic membranes, a simple mathematical model has been developed to describe flow through a gas separation membrane that has a primary mode of flow through very small pores but that has a secondary mode of flow through undesirably large pores. This model permits separation factors to be calculated for a specified gas pair as a function of the molecular weights and molecular diameters of the gases, the membrane pore diameter, and the diameter and number of defects. This model will be described, and key results from the model will be presented. The separation factors of the authors membranes continue to be determined using a permeance test system that measures flows of pure gases through a membrane at temperatures up to 275{degrees}C. A primary goal of this project for FY 1996 is to develop a mixed gas separation system for measuring the separation efficiency of membranes at higher temperatures. Performance criteria have been established for the planned mixed gas separation system and design of the system has been completed. The test system is designed to measure the separation efficiency of membranes at temperatures up to 600{degrees}C and pressures up to 100 psi by separating the constituents of a gas mixture containing hydrogen. The system will accommodate the authors typical experimental membrane that is tubular and has a diameter of about 9 mm and a length of about 23 cm. The design of the new test system and its expected performance will be discussed.

  4. Ceramic membranes for high temperature hydrogen separation

    Energy Technology Data Exchange (ETDEWEB)

    Adcock, K.D.; Fain, D.E.; James, D.L.; Powell, L.E.; Raj, T.; Roettger, G.E.; Sutton, T.G. [East Tennessee Technology Park, Oak Ridge, TN (United States)

    1997-12-01

    The separative performance of the authors` ceramic membranes has been determined in the past using a permeance test system that measured flows of pure gases through a membrane at temperatures up to 275 C. From these data, the separation factor was determined for a particular gas pair from the ratio of the pure gas specific flows. An important project goal this year has been to build a Mixed Gas Separation System (MGSS) for measuring the separation efficiencies of membranes at higher temperatures and using mixed gases. The MGSS test system has been built, and initial operation has been achieved. The MGSS is capable of measuring the separation efficiency of membranes at temperatures up to 600 C and pressures up to 100 psi using a binary gas mixture such as hydrogen/methane. The mixed gas is fed into a tubular membrane at pressures up to 100 psi, and the membrane separates the feed gas mixture into a permeate stream and a raffinate stream. The test membrane is sealed in a stainless steel holder that is mounted in a split tube furnace to permit membrane separations to be evaluated at temperatures up to 600 C. The compositions of the three gas streams are measured by a gas chromatograph equipped with thermal conductivity detectors. The test system also measures the temperatures and pressures of all three gas streams as well as the flow rate of the feed stream. These data taken over a range of flows and pressures permit the separation efficiency to be determined as a function of the operating conditions. A mathematical model of the separation has been developed that permits the data to be reduced and the separation factor for the membrane to be determined.

  5. Hydrogen production from high temperature electrolysis and fusion reactor

    International Nuclear Information System (INIS)

    Dang, V.D.; Steinberg, J.F.; Issacs, H.S.; Lazareth, O.; Powell, J.R.; Salzano, F.J.

    1978-01-01

    Production of hydrogen from high temperature electrolysis of steam coupled with a fusion reactor is studied. The process includes three major components: the fusion reactor, the high temperature electrolyzer and the power conversion cycle each of which is discussed in the paper. Detailed process design and analysis of the system is examined. A parametric study on the effect of process efficiency is presented

  6. High temperature equation of state of metallic hydrogen

    International Nuclear Information System (INIS)

    Shvets, V. T.

    2007-01-01

    The equation of state of liquid metallic hydrogen is solved numerically. Investigations are carried out at temperatures from 3000 to 20 000 K and densities from 0.2 to 3 mol/cm 3 , which correspond both to the experimental conditions under which metallic hydrogen is produced on earth and the conditions in the cores of giant planets of the solar system such as Jupiter and Saturn. It is assumed that hydrogen is in an atomic state and all its electrons are collectivized. Perturbation theory in the electron-proton interaction is applied to determine the thermodynamic potentials of metallic hydrogen. The electron subsystem is considered in the randomphase approximation with regard to the exchange interaction and the correlation of electrons in the local-field approximation. The proton-proton interaction is taken into account in the hard-spheres approximation. The thermodynamic characteristics of metallic hydrogen are calculated with regard to the zero-, second-, and third-order perturbation theory terms. The third-order term proves to be rather essential at moderately high temperatures and densities, although it is much smaller than the second-order term. The thermodynamic potentials of metallic hydrogen are monotonically increasing functions of density and temperature. The values of pressure for the temperatures and pressures that are characteristic of the conditions under which metallic hydrogen is produced on earth coincide with the corresponding values reported by the discoverers of metallic hydrogen to a high degree of accuracy. The temperature and density ranges are found in which there exists a liquid phase of metallic hydrogen

  7. Hydrogen production from fusion reactors coupled with high temperature electrolysis

    International Nuclear Information System (INIS)

    Fillo, J.A.; Powell, J.R.; Steinberg, M.

    The decreasing availability of fossil fuels emphasizes the need to develop systems which will produce synthetic fuel to substitute for and complement the natural supply. An important first step in the synthesis of liquid and gaseous fuels is the production of hydrogen. Thermonuclear fusion offers an inexhaustible source of energy for the production of hydrogen from water. Processes which may be considered for this purpose include electrolysis, thermochemical decomposition or thermochemical-electrochemical hybrid cycles. Preliminary studies at Brookhaven indicate that high temperature electrolysis has the highest potential efficiency for production of hydrogen from fusion. Depending on design electric generation efficiencies of approximately 40 to 60 percent and hydrogen production efficiencies of approximately 50 to 70 percent are projected for fusion reactors using high temperature blankets

  8. Hydrogenation and high temperature oxidation of Zirconium claddings

    International Nuclear Information System (INIS)

    Novotny, T.; Perez-Feró, E.; Horváth, M.

    2015-01-01

    In the last few years a new series of experiments started for supporting the new LOCA criteria, considering the proposals of US NRC. The effects which can cause the embrittlement of VVER fuel claddings were reviewed and evaluated in the framework of the project. The purpose of the work was to determine how the fuel cladding’s hydrogen uptake under normal operating conditions, effect the behavior of the cladding under LOCA conditions. As a first step a gas system equipment with gas valves and pressure gauge was built, in which the zirconium alloy can absorb hydrogen under controlled conditions. In this apparatus E110 (produced by electrolytic method, currently used at Paks NPP) and E110G (produced by a new technology) alloys were hydrogenated to predetermined hydrogen contents. According the results of ring compression tests the E110G alloys lose their ductility above 3200 ppm hydrogen content. This limit can be applied to determine the ductile-brittle transition of the nuclear fuel claddings. After the hydrogenation, high temperature oxidation experiments were carried out on the E110G and E110 samples at 1000 °C and 1200 °C. 16 pieces of E110G and 8 samples of E110 with 300 ppm and 600 ppm hydrogen content were tested. The oxidation of the specimens was performed in steam, under isothermal conditions. Based on the ring compression tests load-displacement curves were recorded. The main objective of the compression tests was to determine the ductile-brittle transition. These results were compared to the results of our previous experiments where the samples did not contain hydrogen. The original claddings showed more ductile behavior than the samples with hydrogen content. The higher hydrogen content resulted in a more brittle mechanical behavior. However no significant difference was observed in the oxidation kinetics of the same cladding types with different hydrogen content. The experiments showed that the normal operating hydrogen uptake of the fuel claddings

  9. Stability analysis of high temperature superconducting coil in liquid hydrogen

    International Nuclear Information System (INIS)

    Nakayama, T.; Yagai, T.; Tsuda, M.; Hamajima, T.

    2007-01-01

    Recently, it is expected that hydrogen plays an important role in energy source including electric power in near future. Liquid hydrogen has high potential for cooling down superconducting coil wound with high temperature superconductors (HTS), such as BSCCO, YBCO. In this paper, we study stabilities of the coils wound with BSCCO tapes, which are immersed in the liquid hydrogen, and compare stability results with those cooled by liquid helium. We treat a minimum propagation zone (MPZ) theory to evaluate the coil stability considering boiling heat flux of the liquid hydrogen, and specific heat, heat conduction and resistivity of HTS materials as a function of temperature. It is found that the coil cooled by the liquid hydrogen has higher stability margin than that cooled by the liquid helium. We compare the stability margins of both coils wound with Bi-2223/Ag tape and Bi-2212/Ag tape in liquid hydrogen. As a result, it is found that the stability of Bi-2212 coil is equivalent to that of Bi-2223 coil in low and high magnetic field, while the maximum current of Bi-2212 coil exceeds a little bit that of Bi-2223 coil in both magnetic fields

  10. High temperature hydrogenation of CaC6

    International Nuclear Information System (INIS)

    Srinivas, G.; Howard, C.A.; Skipper, N.T.; Bennington, S.M.; Ellerby, M.

    2009-01-01

    The structure and superconducting properties of high temperature hydrogenated calcium-graphite intercalation compound, CaC 6 have been investigated using room temperature X-ray diffraction, and temperature and field dependence of magnetisation. It is found that the hydrogenation can only decompose the CaC 6 phase, and generate a mixture of CaH 2 and graphite as the final compound. The hydrogenation of CaC 6 also reveals a degradation of its superconducting properties. The experimental results are discussed in detail and it is found that the formation of stable CaH 2 and deintercalation are the main source for observed phase separation and suppression in superconductivity.

  11. High temperature electrolysis for hydrogen production using nuclear energy

    International Nuclear Information System (INIS)

    Herring, J. Stephen; O'brien, James E.; Stoots, Carl M.; Hawkes, Grant L.; Hartvigsen, Joseph J.

    2005-01-01

    High-temperature nuclear reactors have the potential for substantially increasing the efficiency of hydrogen production from water splitting, which can be accomplished via high-temperature electrolysis (HTE) or thermochemical processes. In order to achieve competitive efficiencies, both processes require high-temperature operation (∼850degC). High-temperature electrolytic water splitting supported by nuclear process heat and electricity has the potential to produce hydrogen with overall system efficiencies of 45 to 55%. At the Idaho National Laboratory, we are developing solid-oxide cells to operate in the steam electrolysis mode. The research program includes both experimental and modeling activities. Experimental results were obtained from ten-cell and 22-cell planar electrolysis stacks, fabricated by Ceramatec, Inc. The electrolysis cells are electrolyte-supported, with scandia-stabilized zirconia electrolytes (∼200 μm thick, 64 cm 2 active area), nickel-cermet steam/hydrogen electrodes, and manganite air-side electrodes. The metallic interconnect plates are fabricated from ferritic stainless steel. The experiments were performed over a range of steam inlet mole fractions, gas glow rates, and current densities. Hydrogen production rates greater than 100 normal liters per hour for 196 hours have been demonstrated. In order to evaluate the performance of large-scale HTE operations, we have developed single-cell models, based on FLUENT, and a process model, using the systems-analysis code HYSYS. (author)

  12. Study on hydrogen production by high temperature electrolysis of steam

    International Nuclear Information System (INIS)

    Hino, Ryutaro; Aita, Hideki; Sekita, Kenji; Haga, Katsuhiro; Iwata, Tomo-o.

    1997-09-01

    In JAERI, design and R and D works on hydrogen production process have been conducted for connecting to the HTTR under construction at the Oarai Research Establishment of JAERI as a nuclear heat utilization system. As for a hydrogen production process by high-temperature electrolysis of steam, laboratory-scale experiments were carried out with a practical electrolysis tube with 12 cells connected in series. Hydrogen was produced at a maximum density of 44 Nml/cm 2 h at 950degC, and know-how of operational procedures and operational experience were also accumulated. Thereafter, a planar electrolysis cell supported by a metallic plate was fabricated in order to improve hydrogen production performance and durability against thermal cycles. In the preliminary test with the planar cell, hydrogen has been produced continuously at a maximum density of 33.6 Nml/cm 2 h at an electrolysis temperature of 950degC. This report presents typical test results mentioned above, a review of previous studies conducted in the world and R and D items required for connecting to the HTTR. (author)

  13. Anomalously deep penetration of hydrogen into niobium under action of pulse high temperature hydrogen plasma

    International Nuclear Information System (INIS)

    Didyk, A.Yu.

    2011-01-01

    The method of elastic recoil detection (ERD) has been used for the study of storage and redistribution processes of hydrogen atoms under the influence of pulse high temperature hydrogen plasma obtained using the 'Plasma Focus' PF-4 set-up in three high purity niobium foils. It was established that with an increase of number of PF-4 set-up pulses there occur spreading and transfer of implanted hydrogen atoms to large depths in three Nb-foils which are significantly larger than the projected range of hydrogen ions (with the velocity ∼ 10 8 cm/s). The maximum hydrogen concentration up to 60 at. % is reached in the nearest to Ph-4 surface of the third Nb-foil at 20 impulses of the Ph-4 set-up. The observed phenomenon can be described by transfer of implanted hydrogen atoms under the action of powerful shock waves, created by pulse hydrogen plasma and (or) by accelerating hydrogen atom diffusion under the influence of compression straining wave at the front of the shock wave at redistribution of hydrogen atoms at large depths. Similar behavior was discovered and described also in series of nickel, vanadium, niobium and tantalum foils (two or three foils and more in a series) including series of foils from heterogeneous (different) materials, which were studied, too

  14. High-temperature study of superconducting hydrogen and deuterium sulfide

    Energy Technology Data Exchange (ETDEWEB)

    Durajski, A.P. [Institute of Physics, Czestochowa University of Technology, Ave. Armii Krajowej 19, 42-200 Czestochowa (Poland); Szczesniak, R. [Institute of Physics, Czestochowa University of Technology, Ave. Armii Krajowej 19, 42-200 Czestochowa (Poland); Institute of Physics, Jan Dlugosz University, Ave. Armii Krajowej 13/15, 42-200 Czestochowa (Poland); Pietronero, L. [Sapienza, Universita di Roma, Dip. Fisica, P. le A. Moro 2, 00185 Roma (Italy); Institute of Complex Systems, CNR, Via dei Taurini 19 Roma (Italy); London Institute for Mathematical Sciences, South Street 22, Mayfair London (United Kingdom)

    2016-05-15

    Hydrogen-rich compounds are extensively explored as candidates for a high-temperature superconductors. Currently, the measured critical temperature of 203 K in hydrogen sulfide (H{sub 3}S) is among the highest over all-known superconductors. In present paper, using the strong-coupling Eliashberg theory of superconductivity, we compared in detail the thermodynamic properties of two samples containing different hydrogen isotopes H{sub 3}S and D{sub 3}S at 150 GPa. Our research indicates that it is possible to reproduce the measured values of critical temperature 203 K and 147 K for H{sub 3}S and D{sub 3}S by using a Coulomb pseudopotential of 0.123 and 0.131, respectively. However, we also discuss a scenario in which the isotope effect is independent of pressure and the Coulomb pseudopotential for D{sub 3}S is smaller than for H{sub 3}S. For both scenarios, the energy gap, specific heat, thermodynamic critical field and related dimensionless ratios are calculated and compared with other conventional superconductors. We shown that the existence of the strong-coupling and retardation effects in the systems analysed result in significant differences between values obtained within the framework of the Eliashberg formalism and the prediction of the Bardeen-Cooper-Schrieffer theory. (copyright 2015 by WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  15. High temperature fast reactor for hydrogen production in Brazil

    International Nuclear Information System (INIS)

    Nascimento, Jamil A. do; Ono, Shizuca; Guimaraes, Lamartine N.F.

    2008-01-01

    The main nuclear reactors technology for the Generation IV, on development phase for utilization after 2030, is the fast reactor type with high temperature output to improve the efficiency of the thermo-electric conversion process and to enable applications of the generated heat in industrial process. Currently, water electrolysis and thermo chemical cycles using very high temperature are studied for large scale and long-term hydrogen production, in the future. With the possible oil scarcity and price rise, and the global warming, this application can play an important role in the changes of the world energy matrix. In this context, it is proposed a fast reactor with very high output temperature, ∼ 1000 deg C. This reactor will have a closed fuel cycle; it will be cooled by lead and loaded with nitride fuel. This reactor may be used for hydrogen, heat and electricity production in Brazil. It is discussed a development strategy of the necessary technologies and some important problems are commented. The proposed concept presents characteristics that meet the requirements of the Generation IV reactor class. (author)

  16. Hydrogen permeation behavior through F82H at high temperature

    Energy Technology Data Exchange (ETDEWEB)

    Matsuda, S.; Katayama, K.; Shimozori, M.; Fukada, S. [Interdisciplinary Graduate School of Engineering Science, Kyushu University, Kyushu (Japan); Ushida, H. [Energy Science and Engineering, Faculty of Engineering, Kyushu University, Kyushu (Japan); Nishikawa, M. [Malaysia-Japan International Institute of Technology, UTM, Kuala Lumpur (Malaysia)

    2015-03-15

    F82H is a primary candidate of structural material and coolant pipe material in a blanket of a fusion reactor. Understanding tritium permeation behavior through F82H is important. In a normal operation of a fusion reactor, the temperature of F82H will be controlled below 550 C. degrees because it is considered that F82H can be used up to 30,000 hours at 550 C. degrees. However, it is necessary to assume the situation where F82H is heated over 550 C. degrees in a severe accident. In this study, hydrogen permeation behavior through F82H was investigated in the temperature range from 500 to 800 C. degrees. In some cases, water vapor was added in a sample gas to investigate an effect of water vapor on hydrogen permeation. The permeability of hydrogen in the temperature range from 500 to 700 C. degrees agreed well with the permeability reported by E. Serra et al. The degradation of the permeability by water vapor was not observed. After the hydrogen permeation reached in a steady state at 700 C. degrees, the F82H sample was heated to 800 C. degrees. The permeability of hydrogen through F82H sample which was once heated up to 800 C. degrees was lower than that of the original one. (authors)

  17. Hydrogen desorption from mechanically milled carbon micro coils hydrogenated at high temperature

    International Nuclear Information System (INIS)

    Yoshio Furuya; Shuichi Izumi; Seiji Motojima; Yukio Hishikawa

    2005-01-01

    Carbon micro coils (CMC) have been prepared by the catalytic pyrolysis of acetylene at 750-800 C. The as grown coils have an almost amorphous structure and contain about 1 mass% hydrogen. They have 0.1 - 10 mm coil length, 1-5 μm coil diameter, 0.1-0.5 μm coil pitch and about 100 m 2 /g specific surface area. They were graphitized, as maintaining the morphology of the coils, by heat-treating at a higher temperature than 2500 C in Ar atmosphere. The layer space (d) of graphitized CMC was determined to be 0.341 nm, forming a 'herringbone' structure with an inclination of 10-40 degree versus the coiled fiber axis, having a specific surface area of about 8 m 2 /g. The hydrogen absorption behaviors of CMC were investigated from RT to 1200 C by a thermal desorption spectrometry (TDS) using a quadrupole mass analyzer. In TDS measurements, pre-existing hydrogen, which was due to the residual acetylene incorporated into CMC on its growing, desorbed from 700 C and peaked at about 900 C. The increment in the main peak of desorbed hydrogen in the as-grown CMC heat-treated at 500 C for 1 h under high pressure of hydrogen gas (1.9 or 8.9 MPa) was not remarkable as is shown in Fig.1. While, in the CMC samples milled mechanically for 1 h at RT using a planetary ball mill, the increase of desorbed hydrogen became to be great with the hydrogen pressure (up to 8.9 MPa) on heat-treating at 500 C, as is shown in Fig.2. In these CMC samples, the building up temperature of the hydrogen desorption was shifted to a lower one and the temperature range of desorption became to be wider than those in the as-grown CMC because of the appearance of another desorption peak at about 600 C in addition to the peak ranging from 850 C to 900 C. The same kind of peak was also slightly observed in as-grown CMC (Fig.1). It is clear that this desorption at about 600 C has contributed to the remarkable increase of desorbed hydrogen in the milled CMC. In this work, values of more than 2 mass% were obtained

  18. High-temperature nuclear reactor power plant cycle for hydrogen and electricity production – numerical analysis

    Directory of Open Access Journals (Sweden)

    Dudek Michał

    2016-01-01

    Full Text Available High temperature gas-cooled nuclear reactor (called HTR or HTGR for both electricity generation and hydrogen production is analysed. The HTR reactor because of the relatively high temperature of coolant could be combined with a steam or gas turbine, as well as with the system for heat delivery for high-temperature hydrogen production. However, the current development of HTR’s allows us to consider achievable working temperature up to 750°C. Due to this fact, industrial-scale hydrogen production using copper-chlorine (Cu-Cl thermochemical cycle is considered and compared with high-temperature electrolysis. Presented calculations show and confirm the potential of HTR’s as a future solution for hydrogen production without CO2 emission. Furthermore, integration of a hightemperature nuclear reactor with a combined cycle for electricity and hydrogen production may reach very high efficiency and could possibly lead to a significant decrease of hydrogen production costs.

  19. HIGH-TEMPERATURE ELECTROLYSIS FOR HYDROGEN PRODUCTION FROM NUCLEAR ENERGY

    Energy Technology Data Exchange (ETDEWEB)

    James E. O& #39; Brien; Carl M. Stoots; J. Stephen Herring; Joseph J. Hartvigsen

    2005-10-01

    An experimental study is under way to assess the performance of solid-oxide cells operating in the steam electrolysis mode for hydrogen production over a temperature range of 800 to 900ºC. Results presented in this paper were obtained from a ten-cell planar electrolysis stack, with an active area of 64 cm2 per cell. The electrolysis cells are electrolyte-supported, with scandia-stabilized zirconia electrolytes (~140 µm thick), nickel-cermet steam/hydrogen electrodes, and manganite air-side electrodes. The metallic interconnect plates are fabricated from ferritic stainless steel. The experiments were performed over a range of steam inlet mole fractions (0.1 - 0.6), gas flow rates (1000 - 4000 sccm), and current densities (0 to 0.38 A/cm2). Steam consumption rates associated with electrolysis were measured directly using inlet and outlet dewpoint instrumentation. Cell operating potentials and cell current were varied using a programmable power supply. Hydrogen production rates up to 90 Normal liters per hour were demonstrated. Values of area-specific resistance and stack internal temperatures are presented as a function of current density. Stack performance is shown to be dependent on inlet steam flow rate.

  20. Silicon Carbide-Based Hydrogen Gas Sensors for High-Temperature Applications

    Directory of Open Access Journals (Sweden)

    Sangchoel Kim

    2013-10-01

    Full Text Available We investigated SiC-based hydrogen gas sensors with metal-insulator-semiconductor (MIS structure for high temperature process monitoring and leak detection applications in fields such as the automotive, chemical and petroleum industries. In this work, a thin tantalum oxide (Ta2O5 layer was exploited with the purpose of sensitivity improvement, because tantalum oxide has good stability at high temperature with high permeability for hydrogen gas. Silicon carbide (SiC was used as a substrate for high-temperature applications. We fabricated Pd/Ta2O5/SiC-based hydrogen gas sensors, and the dependence of their I-V characteristics and capacitance response properties on hydrogen concentrations were analyzed in the temperature range from room temperature to 500 °C. According to the results, our sensor shows promising performance for hydrogen gas detection at high temperatures.

  1. Plasma Temperature Determination of Hydrogen Containing High-Frequency Electrodeless Lamps by Intensity Distribution Measurements of Hydrogen Molecular Band

    OpenAIRE

    Gavare, Zanda; Revalde, Gita; Skudra, Atis

    2010-01-01

    The goal of the present work was the investigation of the possibility to use intensity distribution of the Q-branch lines of the hydrogen Fulcher-α diagonal band (d3Πu−→a3∑g+ electronic transition; Q-branch with v=v′=2) to determine the temperature of hydrogen containing high-frequency electrodeless lamps (HFEDLs). The values of the rotational temperatures have been obtained from the relative intensity distributions for hydrogen-helium and hydrogen-argon HFEDLs depending on the applied curren...

  2. LARGE-SCALE HYDROGEN PRODUCTION FROM NUCLEAR ENERGY USING HIGH TEMPERATURE ELECTROLYSIS

    International Nuclear Information System (INIS)

    O'Brien, James E.

    2010-01-01

    Hydrogen can be produced from water splitting with relatively high efficiency using high-temperature electrolysis. This technology makes use of solid-oxide cells, running in the electrolysis mode to produce hydrogen from steam, while consuming electricity and high-temperature process heat. When coupled to an advanced high temperature nuclear reactor, the overall thermal-to-hydrogen efficiency for high-temperature electrolysis can be as high as 50%, which is about double the overall efficiency of conventional low-temperature electrolysis. Current large-scale hydrogen production is based almost exclusively on steam reforming of methane, a method that consumes a precious fossil fuel while emitting carbon dioxide to the atmosphere. Demand for hydrogen is increasing rapidly for refining of increasingly low-grade petroleum resources, such as the Athabasca oil sands and for ammonia-based fertilizer production. Large quantities of hydrogen are also required for carbon-efficient conversion of biomass to liquid fuels. With supplemental nuclear hydrogen, almost all of the carbon in the biomass can be converted to liquid fuels in a nearly carbon-neutral fashion. Ultimately, hydrogen may be employed as a direct transportation fuel in a 'hydrogen economy.' The large quantity of hydrogen that would be required for this concept should be produced without consuming fossil fuels or emitting greenhouse gases. An overview of the high-temperature electrolysis technology will be presented, including basic theory, modeling, and experimental activities. Modeling activities include both computational fluid dynamics and large-scale systems analysis. We have also demonstrated high-temperature electrolysis in our laboratory at the 15 kW scale, achieving a hydrogen production rate in excess of 5500 L/hr.

  3. Plasma Temperature Determination of Hydrogen Containing High-Frequency Electrode less Lamps by Intensity Distribution Measurements of Hydrogen Molecular Band

    International Nuclear Information System (INIS)

    Gavare, Z.; Revalde, G.; Skudra, A.

    2011-01-01

    The goal of the present work was the investigation of the possibility to use intensity distribution of the Q-branch lines of the hydrogen Fulcher-a diagonal band (d3η u- a3Σg + electronic transition; Q-branch with ν=ν=2) to determine the temperature of hydrogen containing high-frequency electrode less lamps (HFEDLs). The values of the rotational temperatures have been obtained from the relative intensity distributions for hydrogen-helium and hydrogen-argon HFEDLs depending on the applied current. The results have been compared with the method of temperature derivation from Doppler profiles of He 667.8 nm and Ar 772.4 nm lines. The results of both methods are in good agreement, showing that the method of gas temperature determination from the intensity distribution in the hydrogen Fulcher-a (2-2)Q band can be used for the hydrogen containing HFEDLs. It was observed that the admixture of 10% hydrogen in the argon HFEDLs significantly reduces the gas temperature

  4. High temperature cathodic charging of hydrogen in zirconium alloys and iron and nickel base alloys

    International Nuclear Information System (INIS)

    John, J.T.; De, P.K.; Gadiyar, H.S.

    1990-01-01

    These investigations lead to the development of a new technique for charging hydrogen into metals and alloys. In this technique a mixture of sulfates and bisulfates of sodium and potassium is kept saturated with water at 250-300degC in an open pyrex glass beaker and electrolysed using platinum anode and the material to be charged as the cathode. Most of the studies were carried out on Zr alloys. It is shown that because of the high hydrogen flux available at the surface and the high diffusivity of hydrogen in metals at these temperatures the materials pick up hydrogen faster and more uniformly than the conventional electrolytic charging at room temperature and high temperature autoclaving in LiOH solutions. Chemical analysis, metallographic examination and XRD studies confirm this. This technique has been used to charge hydrogen into many iron and nickel base austentic alloys, which are very resistant to hydrogen pick up and to H-embrittlement. Since this involved a novel method of electrolysing water, the hydrogen/deuterium isotopic ratio has been studied. At this temperatures the D/H ratio in the evolved hydrogen gas was found to be closer to the value in the liquid water, which means a smaller separation factor. This confirm the earlier observation that separation factor decreases with increase of temperature. (author). 16 refs., 21 fi gs., 6 tabs

  5. Precursors-Derived Ceramic Membranes for High-Temperature Separation of Hydrogen

    OpenAIRE

    Yuji, Iwamoto

    2007-01-01

    This review describes recent progress in the development of hydrogen-permselective ceramic membranes derived from organometallic precursors. Microstructure and gas transport property of microporous amorphous silica-based membranes are briefly described. Then, high-temperature hydrogen permselectivity, hydrothermal stability as well as hydrogen/steam selectivity of the amorphous silica-based membranes are discussed from a viewpoint of application to membrane reactors for conversion enhancement...

  6. Hydrogen termination of CVD diamond films by high-temperature annealing at atmospheric pressure

    NARCIS (Netherlands)

    Seshan, V.; Ullien, D.; Castellanos-Gomez, A.; Sachdeva, S.; Murthy, D.H.K.; Savenije, T.J.; Ahmad, H.A.; Nunney, T.S.; Janssens, S.D.; Haenen, K.; Nesládek, M.; Van der Zant, H.S.J.; Sudhölter, E.J.R.; De Smet, L.C.P.M.

    2013-01-01

    A high-temperature procedure to hydrogenate diamond films using molecular hydrogen at atmospheric pressure was explored. Undoped and doped chemical vapour deposited (CVD) polycrystalline diamond films were treated according to our annealing method using a H2 gas flow down to ?50 ml/min (STP) at

  7. Basic study on high temperature gas cooled reactor technology for hydrogen production

    International Nuclear Information System (INIS)

    Chang, Jong Hwa; Lee, W. J.; Lee, H. M.

    2003-01-01

    The annual production of hydrogen in the world is about 500 billion m 3 . Currently hydrogen is consumed mainly in chemical industries. However hydrogen has huge potential to be consumed in transportation sector in coming decades. Assuming that 10% of fossil energy in transportation sector is substituted by hydrogen in 2020, the hydrogen in the sector will exceed current hydrogen consumption by more than 2.5 times. Currently hydrogen is mainly produced by steam reforming of natural gas. Steam reforming process is chiefest way to produce hydrogen for mass production. In the future, hydrogen has to be produced in a way to minimize CO2 emission during its production process as well as to satisfy economic competition. One of the alternatives to produce hydrogen under such criteria is using heat source of high-temperature gas-cooled reactor. The high-temperature gas-cooled reactor represents one type of the next generation of nuclear reactors for safe and reliable operation as well as for efficient and economic generation of energy

  8. High-temperature effect of hydrogen on sintered alpha-silicon carbide

    Science.gov (United States)

    Hallum, G. W.; Herbell, T. P.

    1986-01-01

    Sintered alpha-silicon carbide was exposed to pure, dry hydrogen at high temperatures for times up to 500 hr. Weight loss and corrosion were seen after 50 hr at temperatures as low as 1000 C. Corrosion of SiC by hydrogen produced grain boundary deterioration at 1100 C and a mixture of grain and grain boundary deterioration at 1300 C. Statistically significant strength reductions were seen in samples exposed to hydrogen for times greater than 50 hr and temperatures above 1100 C. Critical fracture origins were identified by fractography as either general grain boundary corrision at 1100 C or as corrosion pits at 1300 C. A maximum strength decrease of approximately 33 percent was seen at 1100 and 1300 C after 500 hr exposure to hydrogen. A computer assisted thermodynamic program was also used to predict possible reaction species of SiC and hydrogen.

  9. System Evaluation and Economic Analysis of a HTGR Powered High-Temperature Electrolysis Hydrogen Production Plant

    International Nuclear Information System (INIS)

    McKellar, Michael G.; Harvego, Edwin A.; Gandrik, Anastasia A.

    2010-01-01

    A design for a commercial-scale high-temperature electrolysis (HTE) plant for hydrogen production has been developed. The HTE plant is powered by a high-temperature gas-cooled reactor (HTGR) whose configuration and operating conditions are based on the latest design parameters planned for the Next Generation Nuclear Plant (NGNP). The current HTGR reference design specifies a reactor power of 600 MWt, with a primary system pressure of 7.0 MPa, and reactor inlet and outlet fluid temperatures of 322 C and 750 C, respectively. The power conversion unit will be a Rankine steam cycle with a power conversion efficiency of 40%. The reference hydrogen production plant operates at a system pressure of 5.0 MPa, and utilizes a steam-sweep system to remove the excess oxygen that is evolved on the anode (oxygen) side of the electrolyzer. The overall system thermal-to-hydrogen production efficiency (based on the higher heating value of the produced hydrogen) is 40.4% at a hydrogen production rate of 1.75 kg/s and an oxygen production rate of 13.8 kg/s. An economic analysis of this plant was performed with realistic financial and cost estimating assumptions. The results of the economic analysis demonstrated that the HTE hydrogen production plant driven by a high-temperature helium-cooled nuclear power plant can deliver hydrogen at a cost of $3.67/kg of hydrogen assuming an internal rate of return, IRR, of 12% and a debt to equity ratio of 80%/20%. A second analysis shows that if the power cycle efficiency increases to 44.4%, the hydrogen production efficiency increases to 42.8% and the hydrogen and oxygen production rates are 1.85 kg/s and 14.6 kg/s respectively. At the higher power cycle efficiency and an IRR of 12% the cost of hydrogen production is $3.50/kg.

  10. Economic Analysis of a Nuclear Reactor Powered High-Temperature Electrolysis Hydrogen Production Plant

    International Nuclear Information System (INIS)

    E. A. Harvego; M. G. McKellar; M. S. Sohal; J. E. O'Brien; J. S. Herring

    2008-01-01

    A reference design for a commercial-scale high-temperature electrolysis (HTE) plant for hydrogen production was developed to provide a basis for comparing the HTE concept with other hydrogen production concepts. The reference plant design is driven by a high-temperature helium-cooled nuclear reactor coupled to a direct Brayton power cycle. The reference design reactor power is 600 MWt, with a primary system pressure of 7.0 MPa, and reactor inlet and outlet fluid temperatures of 540 C and 900 C, respectively. The electrolysis unit used to produce hydrogen includes 4,009,177 cells with a per-cell active area of 225 cm2. The optimized design for the reference hydrogen production plant operates at a system pressure of 5.0 MPa, and utilizes an air-sweep system to remove the excess oxygen that is evolved on the anode (oxygen) side of the electrolyzer. The inlet air for the air-sweep system is compressed to the system operating pressure of 5.0 MPa in a four-stage compressor with intercooling. The alternating-current, AC, to direct-current, DC, conversion efficiency is 96%. The overall system thermal-to-hydrogen production efficiency (based on the lower heating value of the produced hydrogen) is 47.12% at a hydrogen production rate of 2.356 kg/s. An economic analysis of this plant was performed using the standardized H2A Analysis Methodology developed by the Department of Energy (DOE) Hydrogen Program, and using realistic financial and cost estimating assumptions. The results of the economic analysis demonstrated that the HTE hydrogen production plant driven by a high-temperature helium-cooled nuclear power plant can deliver hydrogen at a competitive cost. A cost of $3.23/kg of hydrogen was calculated assuming an internal rate of return of 10%

  11. Penetration of hydrogen isotopes through EhI 698 alloy at high pressure and temperature

    International Nuclear Information System (INIS)

    Bystritskij, V.M.; Voznyak, Ya.; Granovskij, V.B.

    1986-01-01

    The paper deals with investigations of the process of hydrogen and deuterium penetration through the high-temperature alloy EhI-698 at a pressure up to 1 kbar and temperature up to 1050 K. Parameters of the process obey Sieverts's law and can be described by Arrenius's and Vant-Goff's equations. The obtained results lead to a conclusion that the alloy EhI-698 is good for vessels to be employed in hydrogen media

  12. Optimizing a High-Temperature Hydrogen Co-generation Reactor for Both Economic and Environmental Performance

    International Nuclear Information System (INIS)

    Weimar, Mark R.; Wood, Thomas W.; Reichmuth, Barbara A.; Johnson, Wayne L.

    2003-01-01

    This paper analyzes outcomes for a 3000 MWt High Temperature Gas Reaction nuclear power plant, given price and cost assumptions, and determined what level of hydrogen and electricity production would optimize the plant economically and environmentally (carbon reduction). The tradeoff between producing hydrogen through steam methane reformation and producing electricity is so disproportionate, that advanced reactors will likely be used only as peaking plants for electricity unless policymakers intervene with incentives to change the mix of electricity and hydrogen. The magnitude of the increase in electric prices or decrease in hydrogen prices required to allow electricity production indicate that substantial error in cost estimates would be required to change our analysis.

  13. Study of the high temperature characteristics of hydrogen storage alloys

    CERN Document Server

    Rong, Li; Shaoxiong, Zhou; Yan, Qi; 10.1016/j.jallcom.2004.07.006

    2005-01-01

    In this work, the phase structure of as-cast and melt-spun (MmY)/sub 1/(NiCoMnAl)/sub 5/ alloys (the content of yttrium is 0-2.5wt.%) and their electrochemical properties were studied with regard to discharge capacity at different temperatures (30-80 degrees C) and cycling life at 30 degrees C. It is found that the substitution of yttrium increase the electrochemical capacity of the compounds and decrease the difference in capacity between as-cast and as-quenched compounds at 30 degrees C. When increasing the yttrium concentration from 0 to 2.5wt.%, the cycling life of both the as-cast and the melt- spun compounds deteriorated, although the latter have a slightly longer cycle life than the former. The remarkable feature of the alloys obtained by yttrium substitution is the improvement of the high temperature electrochemical properties. It shows that the stability of the hydrides is increased. Compared with the as-cast alloys, the melt-spun ribbons have higher electrochemical charge /discharge capacity in the ...

  14. Hydrogen Production System with High Temperature Electrolysis for Nuclear Power Plant

    International Nuclear Information System (INIS)

    Kentaro, Matsunaga; Eiji, Hoashi; Seiji, Fujiwara; Masato, Yoshino; Taka, Ogawa; Shigeo, Kasai

    2006-01-01

    Steam electrolysis with solid oxide cells is one of the most promising methods for hydrogen production, which has the potential to be high efficiency. Its most parts consist of environmentally sound and common materials. Recent development of ceramics with high ionic conductivity suggests the possibility of widening the range of operating temperature with maintaining the high efficiency. Toshiba is constructing a hydrogen production system with solid oxide electrolysis cells for nuclear power plants. Tubular-type cells using YSZ (Yttria-Stabilized- Zirconia) as electrolyte showed good performance of steam electrolysis at 800 to 900 deg C. Larger electrolysis cells with present configuration are to be combined with High Temperature Reactors. The hydrogen production efficiency on the present designed system is expected around 50% at 800 to 900 deg C of operating temperature. For the Fast Reactors, 'advanced cell' with higher efficiency at lower temperature are to be introduced. (authors)

  15. Design Configurations and Coupling High Temperature Gas-Cooled Reactor and Hydrogen Plant

    International Nuclear Information System (INIS)

    Chang H. Oh; Eung Soo Kim; Steven Sherman

    2008-01-01

    The US Department of Energy is investigating the use of high-temperature nuclear reactors to produce hydrogen using either thermochemical cycles or high-temperature electrolysis. Although the hydrogen production processes are in an early stage of development, coupling either of these processes to the high-temperature reactor requires both efficient heat transfer and adequate separation of the facilities to assure that off-normal events in the production facility do not impact the nuclear power plant. An intermediate heat transport loop will be required to separate the operations and safety functions of the nuclear and hydrogen plants. A next generation high-temperature reactor could be envisioned as a single-purpose facility that produces hydrogen or a dual-purpose facility that produces hydrogen and electricity. Early plants, such as the proposed Next Generation Nuclear Plant (NGNP), may be dual-purpose facilities that demonstrate both hydrogen and efficient electrical generation. Later plants could be single-purpose facilities. At this stage of development, both single- and dual-purpose facilities need to be understood

  16. Hydrogen production methods efficiency coupled to an advanced high temperature accelerator driven system

    International Nuclear Information System (INIS)

    Rodríguez, Daniel González; Lira, Carlos Alberto Brayner de Oliveira

    2017-01-01

    The hydrogen economy is one of the most promising concepts for the energy future. In this scenario, oil is replaced by hydrogen as an energy carrier. This hydrogen, rather than oil, must be produced in volumes not provided by the currently employed methods. In this work two high temperature hydrogen production methods coupled to an advanced nuclear system are presented. A new design of a pebbled-bed accelerator nuclear driven system called TADSEA is chosen because of the advantages it has in matters of transmutation and safety. For the conceptual design of the high temperature electrolysis process a detailed computational fluid dynamics model was developed to analyze the solid oxide electrolytic cell that has a huge influence on the process efficiency. A detailed flowsheet of the high temperature electrolysis process coupled to TADSEA through a Brayton gas cycle was developed using chemical process simulation software: Aspen HYSYS®. The model with optimized operating conditions produces 0.1627 kg/s of hydrogen, resulting in an overall process efficiency of 34.51%, a value in the range of results reported by other authors. A conceptual design of the iodine-sulfur thermochemical water splitting cycle was also developed. The overall efficiency of the process was calculated performing an energy balance resulting in 22.56%. The values of efficiency, hydrogen production rate and energy consumption of the proposed models are in the values considered acceptable in the hydrogen economy concept, being also compatible with the TADSEA design parameters. (author)

  17. Hydrogen production methods efficiency coupled to an advanced high temperature accelerator driven system

    Energy Technology Data Exchange (ETDEWEB)

    Rodríguez, Daniel González; Lira, Carlos Alberto Brayner de Oliveira [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Departamento de Energia Nuclear; Fernández, Carlos García, E-mail: danielgonro@gmail.com, E-mail: mmhamada@ipen.br [Instituto Superior de Tecnologías y Ciencias aplicadas (InSTEC), La Habana (Cuba)

    2017-07-01

    The hydrogen economy is one of the most promising concepts for the energy future. In this scenario, oil is replaced by hydrogen as an energy carrier. This hydrogen, rather than oil, must be produced in volumes not provided by the currently employed methods. In this work two high temperature hydrogen production methods coupled to an advanced nuclear system are presented. A new design of a pebbled-bed accelerator nuclear driven system called TADSEA is chosen because of the advantages it has in matters of transmutation and safety. For the conceptual design of the high temperature electrolysis process a detailed computational fluid dynamics model was developed to analyze the solid oxide electrolytic cell that has a huge influence on the process efficiency. A detailed flowsheet of the high temperature electrolysis process coupled to TADSEA through a Brayton gas cycle was developed using chemical process simulation software: Aspen HYSYS®. The model with optimized operating conditions produces 0.1627 kg/s of hydrogen, resulting in an overall process efficiency of 34.51%, a value in the range of results reported by other authors. A conceptual design of the iodine-sulfur thermochemical water splitting cycle was also developed. The overall efficiency of the process was calculated performing an energy balance resulting in 22.56%. The values of efficiency, hydrogen production rate and energy consumption of the proposed models are in the values considered acceptable in the hydrogen economy concept, being also compatible with the TADSEA design parameters. (author)

  18. Preliminary estimations on the heat recovery method for hydrogen production by the high temperature steam electrolysis

    International Nuclear Information System (INIS)

    Koh, Jae Hwa; Yoon, Duck Joo

    2009-01-01

    As a part of the project 'development of hydrogen production technologies by high temperature electrolysis using very high temperature reactor', we have developed an electrolyzer model for high temperature steam electrolysis (HTSE) system and carried out some preliminary estimations on the effects of heat recovery on the HTSE hydrogen production system. To produce massive hydrogen by using nuclear energy, the HTSE process is one of the promising technologies with sulfur-iodine and hybrid sulfur process. The HTSE produces hydrogen through electrochemical reaction within the solid oxide electrolysis cell (SOEC), which is a reverse reaction of solid oxide fuel cell (SOFC). The HTSE system generally operates in the temperature range of 700∼900 .deg. C. Advantages of HTSE hydrogen production are (a) clean hydrogen production from water without carbon oxide emission, (b) synergy effect due to using the current SOFC technology and (c) higher thermal efficiency of system when it is coupled nuclear reactor. Since the HTSE system operates over 700 .deg. C, the use of heat recovery is an important consideration for higher efficiency. In this paper, four different heat recovery configurations for the HTSE system have been investigated and estimated

  19. CHALLENGES IN GENERATING HYDROGEN BY HIGH TEMPERATURE ELECTROLYSIS USING SOLID OXIDE CELLS

    Energy Technology Data Exchange (ETDEWEB)

    M. S. Sohal; J. E. O' Brien; C. M. Stoots; M. G. McKellar; J. S. Herring; E. A. Harvego

    2008-03-01

    Idaho National Laboratory’s (INL) high temperature electrolysis research to generate hydrogen using solid oxide electrolysis cells is presented in this paper. The research results reported here have been obtained in a laboratory-scale apparatus. These results and common scale-up issues also indicate that for the technology to be successful in a large industrial setting, several technical, economical, and manufacturing issues have to be resolved. Some of the issues related to solid oxide cells are stack design and performance optimization, identification and evaluation of cell performance degradation parameters and processes, integrity and reliability of the solid oxide electrolysis (SOEC) stacks, life-time prediction and extension of the SOEC stack, and cost reduction and economic manufacturing of the SOEC stacks. Besides the solid oxide cells, balance of the hydrogen generating plant also needs significant development. These issues are process and ohmic heat source needed for maintaining the reaction temperature (~830°C), high temperature heat exchangers and recuperators, equal distribution of the reactants into each cell, system analysis of hydrogen and associated energy generating plant, and cost optimization. An economic analysis of this plant was performed using the standardized H2A Analysis Methodology developed by the Department of Energy (DOE) Hydrogen Program, and using realistic financial and cost estimating assumptions. The results of the economic analysis demonstrated that the HTE hydrogen production plant driven by a high-temperature helium-cooled nuclear power plant can deliver hydrogen at a cost of $3.23/kg of hydrogen assuming an internal rate of return of 10%. These issues need interdisciplinary research effort of federal laboratories, solid oxide cell manufacturers, hydrogen consumers, and other such stakeholders. This paper discusses research and development accomplished by INL on such issues and highlights associated challenges that need to

  20. Ultrasonic and metallographic studies on AISI 4140 steel exposed to hydrogen at high pressure and temperature

    Science.gov (United States)

    Oruganti, Malavika

    This thesis conducts an investigation to study the effects of hydrogen exposure at high temperature and pressure on the behavior of AISI 4140 steel. Piezoelectric ultrasonic technique was primarily used to evaluate surface longitudinal wave velocity and defect geometry variations, as related to time after exposure to hydrogen at high temperature and pressure. Critically refracted longitudinal wave technique was used for the former and pulse-echo technique for the latter. Optical microscopy and scanning electron microscopy were used to correlate the ultrasonic results with the microstructure of the steel and to provide better insight into the steel behavior. The results of the investigation indicate that frequency analysis of the defect echo, determined using the pulse-echo technique at regular intervals of time, appears to be a promising tool for monitoring defect growth induced by a high temperature and high pressure hydrogen-related attack.

  1. Heat pump cycle by hydrogen-absorbing alloys to assist high-temperature gas-cooled reactor in producing hydrogen

    International Nuclear Information System (INIS)

    Satoshi, Fukada; Nobutaka, Hayashi

    2010-01-01

    A chemical heat pump system using two hydrogen-absorbing alloys is proposed to utilise heat exhausted from a high-temperature source such as a high-temperature gas-cooled reactor (HTGR), more efficiently. The heat pump system is designed to produce H 2 based on the S-I cycle more efficiently. The overall system proposed here consists of HTGR, He gas turbines, chemical heat pumps and reaction vessels corresponding to the three-step decomposition reactions comprised in the S-I process. A fundamental research is experimentally performed on heat generation in a single bed packed with a hydrogen-absorbing alloy that may work at the H 2 production temperature. The hydrogen-absorbing alloy of Zr(V 1-x Fe x ) 2 is selected as a material that has a proper plateau pressure for the heat pump system operated between the input and output temperatures of HTGR and reaction vessels of the S-I cycle. Temperature jump due to heat generated when the alloy absorbs H 2 proves that the alloy-H 2 system can heat up the exhaust gas even at 600 deg. C without any external mechanical force. (authors)

  2. Hydrogen production by high temperature electrolysis of water vapour and nuclear reactors

    International Nuclear Information System (INIS)

    Jean-Pierre Py; Alain Capitaine

    2006-01-01

    This paper presents hydrogen production by a nuclear reactor (High Temperature Reactor, HTR or Pressurized Water Reactor, PWR) coupled to a High Temperature Electrolyser (HTE) plant. With respect to the coupling of a HTR with a HTE plant, EDF and AREVA NP had previously selected a combined cycle HTR scheme to convert the reactor heat into electricity. In that case, the steam required for the electrolyser plant is provided either directly from the steam turbine cycle or from a heat exchanger connected with such cycle. Hydrogen efficiency production is valued using high temperature electrolysis. Electrolysis production of hydrogen can be performed with significantly higher thermal efficiencies by operating in the steam phase than in the water phase. The electrolysis performance is assessed with solid oxide and solid proton electrolysis cells. The efficiency from the three operating conditions (endo-thermal, auto-thermal and thermo-neutral) of a high temperature electrolysis process is evaluated. The technical difficulties to use the gases enthalpy to heat the water are analyzed, taking into account efficiency and technological challenges. EDF and AREVA NP have performed an analysis to select an optimized process giving consideration to plant efficiency, plant operation, investment and production costs. The paper provides pathways and identifies R and D actions to reach hydrogen production costs competitive with those of other hydrogen production processes. (authors)

  3. Effects of temperature on SCC propagation in high temperature water injected with hydrogen peroxide

    International Nuclear Information System (INIS)

    Nakano, Junichi; Sato, Tomonori; Kato, Chiaki; Yoshiyuki, Kaji; Yamamoto, Masahiro; Tsukada, Takashi

    2012-09-01

    To understand the stress corrosion cracking (SCC) behaviour of austenitic stainless steels (SSs) in the boiling water reactor (BWR) coolant environment, it is significant to investigate the effect of hydrogen peroxide (H 2 O 2 ) produced by the radiolysis of water on SCC under the various water chemistry and operational conditions. At the start-up or shut-down periods, for example, the conditions of radiation and temperature on the structural materials are different from those during the plant normal operation, and may be influencing on SCC behaviour. Therefore, the effect of temperature on SCC in high temperature water injected with H 2 O 2 was evaluated by SCC propagation test at the present study. Oxide films on the metal surface in crack were examined and the thermal equilibrium diagram was calculated to estimate the environmental situation in the crack. On the thermally sensitized type 304 SS, crack growth tests were conducted in high temperature water injected with H 2 O 2 to simulate water radiolysis in the core. Small CT type specimens with a width of 15.5 mm and thickness of 6.2 mm were machined from the sensitized SS. SCC growth tests were conducted in high temperature water injected with 100 ppb H 2 O 2 at 453 and 561 K. To minimize H 2 O 2 decomposition by a contact with metal surface of autoclave, the CT specimen was isolated from inner surface of the autoclave by the inner modules made of polytetrafluoroethylene (PTFE), and PTFE lining was also used for the inner surface of inlet and sampling tubes. Base on the measurement of sampled water, it was confirmed that 80-90 % of injected H 2 O 2 remained around the CT specimen in autoclave. Constant load at initial K levels of 11-20 MPam 1/2 was applied to the CT specimens during crack growth tests. After crack growth tests, CT specimens were split into two pieces on the plane of crack propagation. Scanning electron microscope (SEM) examination and laser Raman spectroscopy for outer oxide layer of oxide

  4. Computational model for a high temperature electrolyzer coupled to a HTTR for efficient nuclear hydrogen production

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez, Daniel; Rojas, Leorlen; Rosales, Jesus; Castro, Landy; Gamez, Abel; Brayner, Carlos, E-mail: danielgonro@gmail.com [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil); Garcia, Lazaro; Garcia, Carlos; Torre, Raciel de la, E-mail: lgarcia@instec.cu [Instituto Superior de Tecnologias y Ciencias Aplicadas (InSTEC), La Habana (Cuba); Sanchez, Danny [Universidade Estadual de Santa Cruz (UESC), Ilheus, BA (Brazil)

    2015-07-01

    High temperature electrolysis process coupled to a very high temperature reactor (VHTR) is one of the most promising methods for hydrogen production using a nuclear reactor as the primary heat source. However there are not references in the scientific publications of a test facility that allow to evaluate the efficiency of the process and other physical parameters that has to be taken into consideration for its accurate application in the hydrogen economy as a massive production method. For this lack of experimental facilities, mathematical models are one of the most used tools to study this process and theirs flowsheets, in which the electrolyzer is the most important component because of its complexity and importance in the process. A computational fluid dynamic (CFD) model for the evaluation and optimization of the electrolyzer of a high temperature electrolysis hydrogen production process flowsheet was developed using ANSYS FLUENT®. Electrolyzer's operational and design parameters will be optimized in order to obtain the maximum hydrogen production and the higher efficiency in the module. This optimized model of the electrolyzer will be incorporated to a chemical process simulation (CPS) code to study the overall high temperature flowsheet coupled to a high temperature accelerator driven system (ADS) that offers advantages in the transmutation of the spent fuel. (author)

  5. Computational model for a high temperature electrolyzer coupled to a HTTR for efficient nuclear hydrogen production

    International Nuclear Information System (INIS)

    Gonzalez, Daniel; Rojas, Leorlen; Rosales, Jesus; Castro, Landy; Gamez, Abel; Brayner, Carlos; Garcia, Lazaro; Garcia, Carlos; Torre, Raciel de la; Sanchez, Danny

    2015-01-01

    High temperature electrolysis process coupled to a very high temperature reactor (VHTR) is one of the most promising methods for hydrogen production using a nuclear reactor as the primary heat source. However there are not references in the scientific publications of a test facility that allow to evaluate the efficiency of the process and other physical parameters that has to be taken into consideration for its accurate application in the hydrogen economy as a massive production method. For this lack of experimental facilities, mathematical models are one of the most used tools to study this process and theirs flowsheets, in which the electrolyzer is the most important component because of its complexity and importance in the process. A computational fluid dynamic (CFD) model for the evaluation and optimization of the electrolyzer of a high temperature electrolysis hydrogen production process flowsheet was developed using ANSYS FLUENT®. Electrolyzer's operational and design parameters will be optimized in order to obtain the maximum hydrogen production and the higher efficiency in the module. This optimized model of the electrolyzer will be incorporated to a chemical process simulation (CPS) code to study the overall high temperature flowsheet coupled to a high temperature accelerator driven system (ADS) that offers advantages in the transmutation of the spent fuel. (author)

  6. Advanced Intermediate Heat Transport Loop Design Configurations for Hydrogen Production Using High Temperature Nuclear Reactors

    International Nuclear Information System (INIS)

    Chang Oh; Cliff Davis; Rober Barner; Paul Pickard

    2005-01-01

    The US Department of Energy is investigating the use of high-temperature nuclear reactors to produce hydrogen using either thermochemical cycles or high-temperature electrolysis. Although the hydrogen production processes are in an early stage of development, coupling either of these processes to the high-temperature reactor requires both efficient heat transfer and adequate separation of the facilities to assure that off-normal events in the production facility do not impact the nuclear power plant. An intermediate heat transport loop will be required to separate the operations and safety functions of the nuclear and hydrogen plants. A next generation high-temperature reactor could be envisioned as a single-purpose facility that produces hydrogen or a dual-purpose facility that produces hydrogen and electricity. Early plants, such as the proposed Next Generation Nuclear Plant (NGNP), may be dual-purpose facilities that demonstrate both hydrogen and efficient electrical generation. Later plants could be single-purpose facilities. At this stage of development, both single- and dual-purpose facilities need to be understood. A number of possible configurations for a system that transfers heat between the nuclear reactor and the hydrogen and/or electrical generation plants were identified. These configurations included both direct and indirect cycles for the production of electricity. Both helium and liquid salts were considered as the working fluid in the intermediate heat transport loop. Methods were developed to perform thermal-hydraulic evaluations and cycle-efficiency evaluations of the different configurations and coolants. The thermal-hydraulic evaluations estimated the sizes of various components in the intermediate heat transport loop for the different configurations. The relative sizes of components provide a relative indication of the capital cost associated with the various configurations. Estimates of the overall cycle efficiency of the various

  7. Summary - Advanced high-temperature reactor for hydrogen and electricity production

    International Nuclear Information System (INIS)

    Forsberg, Charles W.

    2001-01-01

    Historically, the production of electricity has been assumed to be the primary application of nuclear energy. That may change. The production of hydrogen (H 2 ) may become a significant application. The technology to produce H 2 using nuclear energy imposes different requirements on the reactor, which, in turn, may require development of new types of reactors. Advanced High Temperature reactors can meet the high temperature requirements to achieve this goal. This alternative application of nuclear energy may necessitate changes in the regulatory structure

  8. Studies of the use of high-temperature nuclear heat from an HTGR for hydrogen production

    Science.gov (United States)

    Peterman, D. D.; Fontaine, R. W.; Quade, R. N.; Halvers, L. J.; Jahromi, A. M.

    1975-01-01

    The results of a study which surveyed various methods of hydrogen production using nuclear and fossil energy are presented. A description of these methods is provided, and efficiencies are calculated for each case. The process designs of systems that utilize the heat from a general atomic high temperature gas cooled reactor with a steam methane reformer and feed the reformer with substitute natural gas manufactured from coal, using reforming temperatures, are presented. The capital costs for these systems and the resultant hydrogen production price for these cases are discussed along with a research and development program.

  9. Studies of the use of high-temperature nuclear heat from an HTGR for hydrogen production

    International Nuclear Information System (INIS)

    Peterman, D.D.; Fontaine, R.W.; Quade, R.N.; Halvers, L.J.; Jahromi, A.M.

    1975-01-01

    The results of a study which surveyed various methods of hydrogen production using nuclear and fossil energy are presented. A description of these methods is provided, and efficiencies are calculated for each case. The process designs of systems that utilize the heat from a general atomic high temperature gas cooled reactor with a steam methane reformer and feed the reformer with substitute natural gas manufactured from coal, using reforming temperatures, are presented. The capital costs for these systems and the resultant hydrogen production price for these cases are discussed along with a research and development program

  10. Sensitivity Studies of Advanced Reactors Coupled to High Temperature Electrolysis (HTE) Hydrogen Production Processes

    International Nuclear Information System (INIS)

    Edwin A. Harvego; Michael G. McKellar; James E. O'Brien; J. Stephen Herring

    2007-01-01

    High Temperature Electrolysis (HTE), when coupled to an advanced nuclear reactor capable of operating at reactor outlet temperatures of 800 C to 950 C, has the potential to efficiently produce the large quantities of hydrogen needed to meet future energy and transportation needs. To evaluate the potential benefits of nuclear-driven hydrogen production, the UniSim process analysis software was used to evaluate different reactor concepts coupled to a reference HTE process design concept. The reference HTE concept included an Intermediate Heat Exchanger and intermediate helium loop to separate the reactor primary system from the HTE process loops and additional heat exchangers to transfer reactor heat from the intermediate loop to the HTE process loops. The two process loops consisted of the water/steam loop feeding the cathode side of a HTE electrolysis stack, and the steam or air sweep loop used to remove oxygen from the anode side. The UniSim model of the process loops included pumps to circulate the working fluids and heat exchangers to recover heat from the oxygen and hydrogen product streams to improve the overall hydrogen production efficiencies. The reference HTE process loop model was coupled to separate UniSim models developed for three different advanced reactor concepts (a high-temperature helium cooled reactor concept and two different supercritical CO2 reactor concepts). Sensitivity studies were then performed to evaluate the affect of reactor outlet temperature on the power cycle efficiency and overall hydrogen production efficiency for each of the reactor power cycles. The results of these sensitivity studies showed that overall power cycle and hydrogen production efficiencies increased with reactor outlet temperature, but the power cycle producing the highest efficiencies varied depending on the temperature range considered

  11. Research and development program of hydrogen production system with high temperature gas-cooled reactor

    International Nuclear Information System (INIS)

    Miyamoto, Y.; Shiozawa, S.; Ogawa, M.; Inagaki, Y.; Nishihara, T.; Shimizu, S.

    2000-01-01

    Japan Atomic Energy Research Institute (JAERI) has been developing a hydrogen production system with a high temperature gas-cooled reactor (HTGR). While the HTGR hydrogen production system has the following advantages compared with a fossil-fired hydrogen production system; low operation cost (economical fuel cost), low CO 2 emission and saving of fossil fuel by use of nuclear heat, it requires some items to be solved as follows; cost reduction of facility such as a reactor, coolant circulation system and so on, development of control and safety technologies. As for the control and safety technologies, JAERI plans demonstration test with hydrogen production system by steam reforming of methane coupling to 30 Wt HTGR, named high temperature engineering test reactor (HTTR). Prior to the demonstration test, a 1/30-scale out-of-pile test facility is in construction for safety review and detailed design of the HTTR hydrogen production system. Also, design study will start for reduction of facility cost. Moreover, basic study on hydrogen production process without CO 2 emission is in progress by thermochemical water splitting. (orig.)

  12. The INNOHYP-CA Project: producing Hydrogen by innovative high-temperature processes

    International Nuclear Information System (INIS)

    Giaconia, A.; Giorgiantoni, G.; Liberatore, R.; Tarquini, P.; Vignolini, M.

    2008-01-01

    The Project, financed under the 6. Framework Programme, has selected a member of innovative high-temperature processes that seem promising for large-scale production of Hydrogen. ENEA has contributed to the analysis of the status of national and regional projects in the European countries and to the definition of guidelines for the future development of these technologies [it

  13. Hydrogen production from biomass pyrolysis gas via high temperature steam reforming process

    International Nuclear Information System (INIS)

    Wongchang, Thawatchai; Patumsawad, Suthum

    2010-01-01

    Full text: The aim of this work has been undertaken as part of the design of continuous hydrogen production using the high temperature steam reforming process. The steady-state test condition was carried out using syngas from biomass pyrolysis, whilst operating at high temperatures between 600 and 1200 degree Celsius. The main reformer operating parameters (e.g. temperature, resident time and steam to biomass ratio (S/B)) have been examined in order to optimize the performance of the reformer. The operating temperature is a key factor in determining the extent to which hydrogen production is increased at higher temperatures (900 -1200 degree Celsius) whilst maintaining the same as resident time and S/B ratio. The effects of exhaust gas composition on heating value were also investigated. The steam reforming process produced methane (CH 4 ) and ethylene (C 2 H 4 ) between 600 to 800 degree Celsius and enhanced production ethane (C 2 H 6 ) at 700 degree Celsius. However carbon monoxide (CO) emission was slightly increased for higher temperatures all conditions. The results show that the use of biomass pyrolysis gas can produce higher hydrogen production from high temperature steam reforming. In addition the increasing reformer efficiency needs to be optimized for different operating conditions. (author)

  14. Hydrogen/Oxygen Reactions at High Pressures and Intermediate Temperatures: Flow Reactor Experiments and Kinetic Modeling

    DEFF Research Database (Denmark)

    Hashemi, Hamid; Christensen, Jakob Munkholt; Glarborg, Peter

    A series of experimental and numerical investigations into hydrogen oxidation at high pressures and intermediate temperatures has been conducted. The experiments were carried out in a high pressure laminar flow reactor at 50 bar pressure and a temperature range of 600–900 K. The equivalence ratio......, the mechanism is used to simulate published data on ignition delay time and laminar burning velocity of hydrogen. The flow reactor results show that at reducing, stoichiometric, and oxidizing conditions, conversion starts at temperatures of 750–775 K, 800–825 K, and 800–825 K, respectively. In oxygen atmosphere......, ignition occurs at the temperature of 775–800 K. In general, the present model provides a good agreement with the measurements in the flow reactor and with recent data on laminar burning velocity and ignition delay time....

  15. Influence of rolling direction and carbide precipitation on IGSCC susceptibility in hydrogenated high temperature water

    International Nuclear Information System (INIS)

    Arioka, Koji; Yamada, Takuyo; Terachi, Takumi; Chiba, Goro

    2005-01-01

    IGSCC growth behaviors of austenitic stainless steels in hydrogenated high temperature water were studied using compact type specimens (0.5T for cold worked materials). The effect of cold rolling direction, alloy composition and carbide precipitation on crack growth behaviors was studied in hydrogenated high temperature water. Then, to examine the effect of cold work and carbide precipitation on IGSCC behaviors, the role of grain boundary sliding studied in high temperature air using CT specimens. The similar dependences of carbide precipitation and cold work on IGSCC and creep behaviors suggest that grain boundary sliding might play an important role by itself or in conjunction with other reactions such as crack tip dissolution etc. (author)

  16. Hydrogen production system coupled with high-temperature gas-cooled reactor (HTTR)

    International Nuclear Information System (INIS)

    Shiozawa, Shusaku

    2003-01-01

    On the HTTR program, R and D on nuclear reactor technology and R and D on thermal application technology such as hydrogen production and so on, are advanced. When carrying out power generation and thermal application such as hydrogen production and so on, it is, at first, necessary to supply nuclear heat safely, stably and in low cost, JAERI carries out some R and Ds on nuclear reactor technology using HTTR. In parallel to this, JAERI also carries out R and D for jointing nuclear reactor system with thermal application systems because of no experience in the world on high temperature heat of about 1,000 centigrade supplied by nuclear reactor except power generation, and R and D on thermochemical decomposition method IS process for producing hydrogen from water without exhaust of carbon dioxide. Here were described summaries on R and D on nuclear reactor technology, R and D on jointing technology using HTTR hydrogen production system, R and D on IS process hydrogen production, and comparison hydrogen production with other processes. (G.K.)

  17. High-temperature oxidation of Zircaloy in hydrogen-steam mixtures

    International Nuclear Information System (INIS)

    Chung, H.M.; Thomas, G.R.

    1982-09-01

    Oxidation rates of Zircaloy-4 cladding tubes have been measured in hydrogen-steam mixtures at 1200 to 1700 0 C. For a given isothermal oxidation temperature, the oxide layer thicknesses have been measured as a function of time, steam supply rate, and hydrogen overpressure. The oxidation rates in the mixtures were compared with similar data obtained in pure steam and helium-steam environments under otherwise identical conditions. The rates in pure steam and helium-steam mixtures were equivalent and comparable to the parabolic rates obtained under steam-saturated conditions and reported in the literature. However, when the helium was replaced with hydrogen of equivalent partial pressure, a significantly smaller oxidation rate was observed. For high steam-supply rates, the oxidation kinetics in a hydrogen-steam mixture were parabolic, but the rate was smaller than for pure steam or helium-steam mixtures. Under otherwise identical conditions, the ratio of the parabolic rate for hydrogen-steam to that for pure steam decreased with increasing temperature and decreasing steam-supply rate

  18. Present status of r and d on hydrogen production by high temperature electrolysis of steam

    International Nuclear Information System (INIS)

    Hino, Ryutaro; Aita, Hideki; Sekita, Kenji; Haga, Katsuhiro; Miyamoto, Yoshiaki; Iwata, Tomo-o.

    1995-08-01

    In JAERI, design and R and D works on hydrogen production process have been conducted for connecting to the HTTR under construction at the Oarai Establishment of the JAERI as the nuclear heat utilization system. As for a hydrogen production process by high-temperature electrolysis of steam, laboratory-scale experiments have been conducted using a practical electrolysis tube with 12 cells connected in series. Hydrogen was produced at a maximum density of 44 Nml/cm 2 h at 950degC, and know-how of operational procedures and operational experience have been also accumulated. Then, a self-supporting planar electrolysis cell was fabricated in order to improve hydrogen production performance. In the preliminary test with the planar cell, hydrogen has been produced continuously at a maximum density of 36 Nml/cm 2 h at lower electrolysis temperature of 850degC. This report presents typical test results mentioned above, a review of previous studies conducted in the world and R and D items required for connecting to the HTTR. (author)

  19. Hydrogen production through high-temperature electrolysis in a solid oxide cell

    International Nuclear Information System (INIS)

    Herring, J.St.; Lessing, P.; O'Brien, J.E.; Stoots, C.; Hartvigsen, J.; Elangovan, S.

    2004-01-01

    An experimental research programme is being conducted by the INEEL and Ceramatec, Inc., to test the high-temperature, electrolytic production of hydrogen from steam using a solid oxide cell. The research team is designing and testing solid oxide cells for operation in the electrolysis mode, producing hydrogen rising a high-temperature heat and electrical energy. The high-temperature heat and the electrical power would be supplied simultaneously by a high-temperature nuclear reactor. Operation at high temperature reduces the electrical energy requirement for electrolysis and also increases the thermal efficiency of the power-generating cycle. The high-temperature electrolysis process will utilize heat from a specialized secondary loop carrying a steam/hydrogen mixture. It is expected that, through the combination of a high-temperature reactor and high-temperature electrolysis, the process will achieve an overall thermal conversion efficiency of 40 to 50%o while avoiding the challenging chemistry and corrosion issues associated with the thermochemical processes. Planar solid oxide cell technology is being utilised because it has the best potential for high efficiency due to minimized voltage and current losses. These losses also decrease with increasing temperature. Initial testing has determined the performance of single 'button' cells. Subsequent testing will investigate the performance of multiple-cell stacks operating in the electrolysis mode. Testing is being performed both at Ceramatec and at INEEL. The first cells to be tested were single cells based on existing materials and fabrication technology developed at Ceramatec for production of solid oxide fuel cells. These cells use a relatively thick (∼ 175 μm) electrolyte of yttria- or scandia-stabilised zirconia, with nickel-zirconia cermet anodes and strontium-doped lanthanum manganite cathodes. Additional custom cells with lanthanum gallate electrolyte have been developed and tested. Results to date have

  20. Materials for high-temperature hydrogen fluorine environments. Final report, June 1976-December 1978

    International Nuclear Information System (INIS)

    Holcombe, C.E. Jr.; Kovach, L.

    1981-03-01

    A determination has been made of the stability of 35 materials under high-temperature, fluorine rich, hydrogen fluoride torch testing. Refractory materials tested included 4 borides, 3 carbides, 3 nitrides, 12 oxides, 1 oxynitride, 1 sulfide, 10 metals, and carbon (10 types). Three materials distinctly performed better than nickel: lanthanum hexaboride, calcium hexaboride, and lanthanum silicon oxynitride. Of these, lanthanum hexaboride is the best candidate tested since it has an estimated upper use temperature > 1726 K, which is above the melting point and more than 300 K above the upper use temperature of nickel

  1. Materials for high-temperature hydrogen fluorine environments. Final report, June 1976-December 1978

    Energy Technology Data Exchange (ETDEWEB)

    Holcombe, C.E. Jr.; Kovach, L.

    1981-03-01

    A determination has been made of the stability of 35 materials under high-temperature, fluorine rich, hydrogen fluoride torch testing. Refractory materials tested included 4 borides, 3 carbides, 3 nitrides, 12 oxides, 1 oxynitride, 1 sulfide, 10 metals, and carbon (10 types). Three materials distinctly performed better than nickel: lanthanum hexaboride, calcium hexaboride, and lanthanum silicon oxynitride. Of these, lanthanum hexaboride is the best candidate tested since it has an estimated upper use temperature > 1726 K, which is above the melting point and more than 300 K above the upper use temperature of nickel.

  2. SCC growth behavior of stainless steel weld heat-affected zone in hydrogenated high temperature water

    International Nuclear Information System (INIS)

    Yamada, Takuyo; Terachi, Takumi; Miyamoto, Tomoki; Arioka, Koji

    2010-01-01

    It is known that the SCC growth rate of stainless steels in high-temperature water is accelerated by cold-work (CW). The weld heat-affected-zone (HAZ) of stainless steels is also deformed by weld shrinkage. However, only little have been reported on the SCC growth of weld HAZ of SUS316 and SUS304 in hydrogenated high-temperature water. Thus, in this present study, SCC growth experiments were performed using weld HAZ of stainless steels, especially to obtain data on the dependence of SCC growth on (1) temperature and (2) hardness in hydrogenated water at temperatures from 250degC to 340degC. And then, the SCC growth behaviors were compared between weld HAZ and CW stainless steels. The following results have been obtained. Significant SCC growth were observed in weld HAZ (SUS316 and SUS304) in hydrogenated water at 320degC. The SCC growth rates of the HAZ are similar to that of 10% CW non-sensitized SUS316, in accordance with that the hardness of weld HAZ is also similar to that of 10% CW SUS316. Temperature dependency of SCC growth of weld HAZ (SUS316 and SUS304) is also similar to that of 10% CW non-sensitized SUS316. That is, no significant SCC were observed in the weld HAZ (SUS316 and SUS304) in hydrogenated water at 340degC. This suggests that SCC growth behaviors of weld HAZ and CW stainless steels are similar and correlated with the hardness or yield strength of the materials, at least in non-sensitized regions. And the similar temperature dependence between the HAZ and CW stainless steels suggests that the SCC growth behaviors are also attributed to the common mechanism. (author)

  3. Performance of CVD and CVR coated carbon-carbon in high temperature hydrogen

    Science.gov (United States)

    Adams, J. W.; Barletta, R. E.; Svandrlik, J.; Vanier, P. E.

    As a part of the component development process for the particle bed reactor (PBR), it is necessary to develop coatings which will be time and temperature stable at extremely high temperatures in flowing hydrogen. These coatings must protect the underlying carbon structure from attack by the hydrogen coolant. Degradation which causes small changes in the reactor component, e.g. hole diameter in the hot frit, can have a profound effect on operation. The ability of a component to withstand repeated temperature cycles is also a coating development issue. Coatings which crack or spall under these conditions would be unacceptable. While refractory carbides appear to be the coating material of choice for carbon substrates being used in PBR components, the method of applying these coatings can have a large effect on their performance. Two deposition processes for these refractory carbides, chemical vapor deposition (CVD) and chemical vapor reaction (CVR), have been evaluated. Screening tests for these coatings consisted of testing of coated 2-D and 3-D weave carbon-carbon in flowing hot hydrogen at one atmosphere. Carbon loss from these samples was measured as a function of time. Exposure temperatures up to 3,000 K were used, and samples were exposed in a cyclical fashion cooling to room temperature between exposures. The results of these measurements are presented along with an evaluation of the relative merits of CVR and CVD coatings for this application.

  4. Effect of dissolved hydrogen on corrosion of 316NG stainless steel in high temperature water

    Energy Technology Data Exchange (ETDEWEB)

    Dong, Lijin [Key Laboratory of Nuclear Materials and Safety Assessment, Institute of Metal Research, Chinese Academy of Sciences, 62 Wencui Road, Shenyang City 110016 (China); Key Laboratory for Anisotropy and Texture of Materials (Ministry of Education), Northeastern University, Shenyang City 110819 (China); Peng, Qunjia, E-mail: qunjiapeng@imr.ac.cn [Key Laboratory of Nuclear Materials and Safety Assessment, Institute of Metal Research, Chinese Academy of Sciences, 62 Wencui Road, Shenyang City 110016 (China); Zhang, Zhiming [Key Laboratory of Nuclear Materials and Safety Assessment, Institute of Metal Research, Chinese Academy of Sciences, 62 Wencui Road, Shenyang City 110016 (China); Shoji, Tetsuo [Frontier Research Initiative, New Industry Creation Hatchery Center, Tohoku University, 6-6-10, Aoba, Aramaki, Aoba-ku, Sendai 980-8579 (Japan); Han, En-Hou; Ke, Wei [Key Laboratory of Nuclear Materials and Safety Assessment, Institute of Metal Research, Chinese Academy of Sciences, 62 Wencui Road, Shenyang City 110016 (China); Wang, Lei [Key Laboratory for Anisotropy and Texture of Materials (Ministry of Education), Northeastern University, Shenyang City 110819 (China)

    2015-12-15

    Highlights: • Dissolved hydrogen (DH) effect on corrosion of stainless steel in high temperature water. • Increasing DH caused decrease of Cr- but increase of Fe-concentrations in the inner oxide layer. • Concentration gradient of Cr and Fe in the inner oxide layer. • DH effect was attributed to the accelerated diffusion of Fe ion in the inner oxide layer. - Abstract: Characterizations of oxide films formed on 316 stainless steel in high temperature, hydrogenated water were conducted. The results show the oxide film consists of an outer layer with oxide particles of Fe–Ni spinel and hematite, and an inner continuous layer of Fe–Cr–Ni spinel. Increasing dissolved hydrogen (DH) concentrations causes decrease of Cr- and increase of Fe-concentrations in the inner layer. A continuous decrease of Cr- and increase of Fe-concentrations was observed from the surface of the inner layer to the oxide/substrate interface. The DH effect is attributed to the enhanced diffusion of Fe ions in the oxide film by hydrogen.

  5. Oxidation of Inconel 625 superalloy upon treatment with oxygen or hydrogen plasma at high temperature

    Czech Academy of Sciences Publication Activity Database

    Vesel, A.; Drenik, A.; Elersic, K.; Mozetič, M.; Kovač, J.; Gyergyek, T.; Stöckel, Jan; Varju, Jozef; Pánek, Radomír; Balat-Pichelin, M.

    2014-01-01

    Roč. 305, June (2014), s. 674-682 ISSN 0169-4332 R&D Projects: GA MŠk(CZ) LM2011021 Institutional support: RVO:61389021 Keywords : Inconel * Oxidation * High temperature * Oxygen plasma * Hydrogen plasma Subject RIV: BL - Plasma and Gas Discharge Physics OBOR OECD: Fluids and plasma physics (including surface physics) Impact factor: 2.711, year: 2014 https://www.sciencedirect.com/science/article/pii/S0169433214007119

  6. High Temperature Electrolysis for Hydrogen Production from Nuclear Energy – TechnologySummary

    Energy Technology Data Exchange (ETDEWEB)

    J. E. O' Brien; C. M. Stoots; J. S. Herring; M. G. McKellar; E. A. Harvego; M. S. Sohal; K. G. Condie

    2010-02-01

    The Department of Energy, Office of Nuclear Energy, has requested that a Hydrogen Technology Down-Selection be performed to identify the hydrogen production technology that has the best potential for timely commercial demonstration and for ultimate deployment with the Next Generation Nuclear Plant (NGNP). An Independent Review Team has been assembled to execute the down-selection. This report has been prepared to provide the members of the Independent Review Team with detailed background information on the High Temperature Electrolysis (HTE) process, hardware, and state of the art. The Idaho National Laboratory has been serving as the lead lab for HTE research and development under the Nuclear Hydrogen Initiative. The INL HTE program has included small-scale experiments, detailed computational modeling, system modeling, and technology demonstration. Aspects of all of these activities are included in this report. In terms of technology demonstration, the INL successfully completed a 1000-hour test of the HTE Integrated Laboratory Scale (ILS) technology demonstration experiment during the fall of 2008. The HTE ILS achieved a hydrogen production rate in excess of 5.7 Nm3/hr, with a power consumption of 18 kW. This hydrogen production rate is far larger than has been demonstrated by any of the thermochemical or hybrid processes to date.

  7. High Temperature Electrolysis for Hydrogen Production from Nuclear Energy - Technology Summary

    International Nuclear Information System (INIS)

    O'Brien, J.E.; Stoots, C.M.; Herring, J.S.; McKellar, M.G.; Harvego, E.A.; Sohal, M.S.; Condie, K.G.

    2010-01-01

    The Department of Energy, Office of Nuclear Energy, has requested that a Hydrogen Technology Down-Selection be performed to identify the hydrogen production technology that has the best potential for timely commercial demonstration and for ultimate deployment with the Next Generation Nuclear Plant (NGNP). An Independent Review Team has been assembled to execute the down-selection. This report has been prepared to provide the members of the Independent Review Team with detailed background information on the High Temperature Electrolysis (HTE) process, hardware, and state of the art. The Idaho National Laboratory has been serving as the lead lab for HTE research and development under the Nuclear Hydrogen Initiative. The INL HTE program has included small-scale experiments, detailed computational modeling, system modeling, and technology demonstration. Aspects of all of these activities are included in this report. In terms of technology demonstration, the INL successfully completed a 1000-hour test of the HTE Integrated Laboratory Scale (ILS) technology demonstration experiment during the fall of 2008. The HTE ILS achieved a hydrogen production rate in excess of 5.7 Nm3/hr, with a power consumption of 18 kW. This hydrogen production rate is far larger than has been demonstrated by any of the thermochemical or hybrid processes to date.

  8. Nanoporous, Metal Carbide, Surface Diffusion Membranes for High Temperature Hydrogen Separations

    Energy Technology Data Exchange (ETDEWEB)

    Way, J. Douglas [Colorado School of Mines, Golden, CO (United States). Dept. of Chemical and Biological Engineering; Wolden, Colin A. [Colorado School of Mines, Golden, CO (United States)

    2013-09-30

    Colorado School of Mines (CSM) developed high temperature, hydrogen permeable membranes that contain no platinum group metals with the goal of separating hydrogen from gas mixtures representative of gasification of carbon feedstocks such as coal or biomass in order to meet DOE NETL 2015 hydrogen membrane performance targets. We employed a dual synthesis strategy centered on transition metal carbides. In the first approach, novel, high temperature, surface diffusion membranes based on nanoporous Mo2C were fabricated on ceramic supports. These were produced in a two step process that consisted of molybdenum oxide deposition followed by thermal carburization. Our best Mo2C surface diffusion membrane achieved a pure hydrogen flux of 367 SCFH/ft2 at a feed pressure of only 20 psig. The highest H2/N2 selectivity obtained with this approach was 4.9. A transport model using “dusty gas” theory was derived to describe the hydrogen transport in the Mo2C coated, surface diffusion membranes. The second class of membranes developed were dense metal foils of BCC metals such as vanadium coated with thin (< 60 nm) Mo2C catalyst layers. We have fabricated a Mo2C/V composite membrane that in pure gas testing delivered a H2 flux of 238 SCFH/ft2 at 600 °C and 100 psig, with no detectable He permeance. This exceeds the 2010 DOE Target flux. This flux is 2.8 times that of pure Pd at the same membrane thickness and test conditions and over 79% of the 2015 flux target. In mixed gas testing we achieved a permeate purity of ≥99.99%, satisfying the permeate purity milestone, but the hydrogen permeance was low, ~0.2 SCFH/ft2.psi. However, during testing of a Mo2C coated Pd alloy membrane with DOE 1 feed gas mixture a hydrogen permeance of >2 SCFH/ft2.psi was obtained which was stable during the entire test, meeting the permeance associated with

  9. Red soil as a regenerable sorbent for high temperature removal of hydrogen sulfide from coal gas

    International Nuclear Information System (INIS)

    Ko, T.-H.; Chu Hsin; Lin, H.-P.; Peng, C.-Y.

    2006-01-01

    In this study, hydrogen sulfide (H 2 S) was removed from coal gas by red soil under high temperature in a fixed-bed reactor. Red soil powders were collected from the northern, center and southern of Taiwan. They were characterized by XRPD, porosity analysis and DCB chemical analysis. Results show that the greater sulfur content of LP red soils is attributed to the higher free iron oxides and suitable sulfidation temperature is around 773 K. High temperature has a negative effect for use red soil as a desulfurization sorbent due to thermodynamic limitation in a reduction atmosphere. During 10 cycles of regeneration, after the first cycle the red soil remained stable with a breakthrough time between 31 and 36 min. Hydrogen adversely affects sulfidation reaction, whereas CO exhibits a positive effect due to a water-shift reaction. COS was formed during the sulfidation stage and this was attributed to the reaction of H 2 S and CO. Results of XRPD indicated that, hematite is the dominant active species in fresh red soil and iron sulfide (FeS) is a product of the reaction between hematite and hydrogen sulfide in red soils. The spinel phase FeAl 2 O 4 was found during regeneration, moreover, the amount of free iron oxides decreased after regeneration indicating the some of the free iron oxide formed a spinel phase, further reducting the overall desulfurization efficiency

  10. System Evaluations and Life-Cycle Cost Analyses for High-Temperature Electrolysis Hydrogen Production Facilities

    Energy Technology Data Exchange (ETDEWEB)

    Edwin A. Harvego; James E. O' Brien; Michael G. McKellar

    2012-05-01

    This report presents results of system evaluations and lifecycle cost analyses performed for several different commercial-scale high-temperature electrolysis (HTE) hydrogen production concepts. The concepts presented in this report rely on grid electricity and non-nuclear high-temperature process heat sources for the required energy inputs. The HYSYS process analysis software was used to evaluate both central plant designs for large-scale hydrogen production (50,000 kg/day or larger) and forecourt plant designs for distributed production and delivery at about 1,500 kg/day. The HYSYS software inherently ensures mass and energy balances across all components and it includes thermodynamic data for all chemical species. The optimized designs described in this report are based on analyses of process flow diagrams that included realistic representations of fluid conditions and component efficiencies and operating parameters for each of the HTE hydrogen production configurations analyzed. As with previous HTE system analyses performed at the INL, a custom electrolyzer model was incorporated into the overall process flow sheet. This electrolyzer model allows for the determination of the average Nernst potential, cell operating voltage, gas outlet temperatures, and electrolyzer efficiency for any specified inlet steam, hydrogen, and sweep-gas flow rates, current density, cell active area, and external heat loss or gain. The lifecycle cost analyses were performed using the H2A analysis methodology developed by the Department of Energy (DOE) Hydrogen Program. This methodology utilizes spreadsheet analysis tools that require detailed plant performance information (obtained from HYSYS), along with financial and cost information to calculate lifecycle costs. There are standard default sets of assumptions that the methodology uses to ensure consistency when comparing the cost of different production or plant design options. However, these assumptions may also be varied within the

  11. The Advanced High-Temperature Reactor (AHTR) for Producing Hydrogen to Manufacture Liquid Fuels

    International Nuclear Information System (INIS)

    Forsberg, C.W.; Peterson, P.F.; Ott, L.

    2004-01-01

    Conventional world oil production is expected to peak within a decade. Shortfalls in production of liquid fuels (gasoline, diesel, and jet fuel) from conventional oil sources are expected to be offset by increased production of fuels from heavy oils and tar sands that are primarily located in the Western Hemisphere (Canada, Venezuela, the United States, and Mexico). Simultaneously, there is a renewed interest in liquid fuels from biomass, such as alcohol; but, biomass production requires fertilizer. Massive quantities of hydrogen (H2) are required (1) to convert heavy oils and tar sands to liquid fuels and (2) to produce fertilizer for production of biomass that can be converted to liquid fuels. If these liquid fuels are to be used while simultaneously minimizing greenhouse emissions, nonfossil methods for the production of H2 are required. Nuclear energy can be used to produce H2. The most efficient methods to produce H2 from nuclear energy involve thermochemical cycles in which high-temperature heat (700 to 850 C) and water are converted to H2 and oxygen. The peak nuclear reactor fuel and coolant temperatures must be significantly higher than the chemical process temperatures to transport heat from the reactor core to an intermediate heat transfer loop and from the intermediate heat transfer loop to the chemical plant. The reactor temperatures required for H2 production are at the limits of practical engineering materials. A new high-temperature reactor concept is being developed for H2 and electricity production: the Advanced High-Temperature Reactor (AHTR). The fuel is a graphite-matrix, coated-particle fuel, the same type that is used in modular high-temperature gas-cooled reactors (MHTGRs). The coolant is a clean molten fluoride salt with a boiling point near 1400 C. The use of a liquid coolant, rather than helium, reduces peak reactor fuel and coolant temperatures 100 to 200 C relative to those of a MHTGR. Liquids are better heat transfer fluids than gases

  12. High-temperature hydrogen-air-steam detonation experiments in the BNL small-scale development apparatus

    International Nuclear Information System (INIS)

    Ciccarelli, G.; Ginsburg, T.; Boccio, J.; Economos, C.; Finfrock, C.; Gerlach, L.; Sato, K.; Kinoshita, M.

    1994-08-01

    The Small-Scale Development Apparatus (SSDA) was constructed to provide a preliminary set of experimental data to characterize the effect of temperature on the ability of hydrogen-air-steam mixtures to undergo detonations and, equally important, to support design of the larger scale High-Temperature Combustion Facility (HTCF) by providing a test bed for solution of a number of high-temperature design and operational problems. The SSDA, the central element of which is a 10-cm inside diameter, 6.1-m long tubular test vessel designed to permit detonation experiments at temperatures up to 700K, was employed to study self-sustained detonations in gaseous mixtures of hydrogen, air, and steam at temperatures between 300K and 650K at a fixed initial pressure of 0.1 MPa. Hydrogen-air mixtures with hydrogen composition from 9 to 60 percent by volume and steam fractions up to 35 percent by volume were studied for stoichiometric hydrogen-air-steam mixtures. Detonation cell size measurements provide clear evidence that the effect of hydrogen-air gas mixture temperature, in the range 300K-650K, is to decrease cell size and, hence, to increase the sensitivity of the mixture to undergo detonations. The effect of steam content, at any given temperature, is to increase the cell size and, thereby, to decrease the sensitivity of stoichiometric hydrogen-air mixtures. The hydrogen-air detonability limits for the 10-cm inside diameter SSDA test vessel, based upon the onset of single-head spin, decreased from 15 percent hydrogen at 300K down to between 9 and 10 percent hydrogen at 650K. The one-dimensional ZND model does a very good job at predicting the overall trends in the cell size data over the range of hydrogen-air-steam mixture compositions and temperature studied in the experiments

  13. Study on introduction scenario of the high temperature gas-cooled reactor hydrogen cogeneration system (GTHTR300C). Part 1

    International Nuclear Information System (INIS)

    Nishihara, Tetsuo; Takeda, Tetsuaki

    2005-09-01

    Japan Atomic Energy Research Institute is carrying out the research and development of the high temperature gas-cooled reactor hydrogen cogeneration system (GTHTR300C) aiming at the practical use around 2030. Preconditions of GTHTR300C introduction are the increase of hydrogen demand and the needs of new nuclear power plants. In order to establish the introduction scenario, it should be clarified that the operational status of existing nuclear power plants, the introduction number of fuel cell vehicles as a main user of hydrogen and the capability of hydrogen supply by existing plants. In this report, estimation of the nuclear power plants that will be decommissioned with a high possibility by 2030 and selection of the model district where the GTHTR300C can be introduced as an alternative system are conducted. Then the hydrogen demand and the capability of hydrogen supply in this district are investigated and the hydrogen supply scenario in 2030 is considered. (author)

  14. High density hydrogen research

    International Nuclear Information System (INIS)

    Hawke, R.S.

    1977-01-01

    The interest in the properties of very dense hydrogen is prompted by its abundance in Saturn and Jupiter and its importance in laser fusion studies. Furthermore, it has been proposed that the metallic form of hydrogen may be a superconductor at relatively high temperatures and/or exist in a metastable phase at ambient pressure. For ten years or more, laboratories have been developing the techniques to study hydrogen in the megabar region (1 megabar = 100 GPa). Three major approaches to study dense hydrogen experimentally have been used, static presses, shockwave compression, and magnetic compression. Static tchniques have crossed the megabar threshold in stiff materials but have not yet been convincingly successful in very compressible hydrogen. Single and double shockwave techniques have improved the precision of the pressure, volume, temperature Equation of State (EOS) of molecular hydrogen (deuterium) up to near 1 Mbar. Multiple shockwave and magnetic techniques have compressed hydrogen to several megabars and densities in the range of the metallic phase. The net result is that hydrogen becomes conducting at a pressure between 2 and 4 megabars. Hence, the possibility of making a significant amount of hydrogen into a metal in a static press remains a formidable challenge. The success of such experiments will hopefully answer the questions about hydrogen's metallic vs. conducting molecular phase, superconductivity, and metastability. 4 figures, 15 references

  15. Influence of hydrogen additions on high-temperature superplasticity of titanium alloys

    International Nuclear Information System (INIS)

    Lederich, R.J.; Sastry, S.M.L.

    1982-01-01

    The effects of the addition of up to 1.0 wt pct hydrogen as a transient alloying element on the superplastic formability (SPF) of fine-grained, equiaxed Ti-6Al-4V (Ti-64) and duplex-annealed Ti-6Al-2Sn-4Zr-2Mo (Ti-6242) were determined. Small amounts of internal hydrogen greatly improve the SPF of the alloys. Formability at 720-900 C was evaluated by an instrumented cone-forming test with continuous monitoring of strain with time. Argon/1 pct hydrogen and argon/4 pct hydrogen gas mixtures were used for charging the alloys with hydrogen as well as for superplastic forming. Hydrogen additions lower the beta-transus temperature of alpha-beta titanium alloys, and the proportions of the alpha and beta phases required for optimum superplasticity can thus be obtained at lower temperatures in hydrogen-modified alloys than in standard alloys. The increased amount of beta phase in the hydrogen-modified titanium alloys reduces the grain growth rates at forming temperature, thus reducing the time-dependent decrease in superplastic strain rate at constant stress or the increase in flow stress at constant strain rate. Process parameters for superplastic forming of Ti-64 and Ti-6242 using argon-hydrogen gas mixtures were determined. 8 references

  16. Hydrogen content, interfacial exchange and hydrogen diffusion in high-temperature protonic conductors based on strontium and barium cerates

    International Nuclear Information System (INIS)

    Vdovin, G.K.; Kurumchin, Eh.Kh.

    2004-01-01

    The hydrogen content and kinetics of the hydrogen exchange in the barium and strontium doped cerates are studied in the reduction atmosphere through the methods of isotope counterbalancing and isotope exchange. The measurements are carried out at 500-840 Deg C and hydrogen pressure of 2.7-16 gPa. It is established, that the hydrogen interfacial exchange proceeds at high velocities through the dissociative-type mechanisms. The effective activation energy of the hydrogen heteroexchange is determined. The coefficient of the hydrogen diffusion in BaCe 0.95 Nd 0.5 O 3-δ is calculated. The hydrogen content per formula unit constituted (0.48±0.05) in the SrCe 0.95 Y 0.05 O 3-δ and (0.60±0.05) in the BaCe 0.95 Nd 0.5 O 3-δ at 550 and 720 Deg C correspondingly and hydrogen pressure of 6.7 gPa [ru

  17. Remarks on the thermochemical production of hydrogen from water using heat from the high temperature reactor

    International Nuclear Information System (INIS)

    Barnert, H.

    1980-06-01

    In this report, some aspects of the production of hydrogen from water using heat from the High Temperature Reactor has been studied. These aspects are: the theoretical potential for economic competitivness, the application of hydrogen in the Heat Market, the size of the market potential in the Federal Republic of Germany and the extent of research and development work. In addition another novel proposal for a thermochemical cycle has been studied. For the description of the theoretical potential for economic competitivness, a definition of the 'coupling', has been introduced, which is thermodynamicaly developed; the thermochemical cycle is compared with the thermochemical cycle. Using the coupling, it becomes possible to describe a relation between thermodynamical parameters and the ecomomical basic data of capital costs. Reasons are given from the theoretical point of view for the application of hydrogen as an energy carrier of high exergetic value in the heat market. The discussion of energy problems as 'questions of global survival' leads here to a proposal for the introduction of the term 'extropy'. The market potential in the Federal Republic of Germany is estimated. A further novel proposal for a thermochemical cycle is the 'hydrocarbon-hybrid-process'. The extent of research and development work is explained. (orig.) [de

  18. Study and modelling of an industrial plant for hydrogen production by High Temperature Steam Electrolysis

    International Nuclear Information System (INIS)

    Bertier, L.

    2012-01-01

    HTSE field (High Temperature Steam Electrolysis) is moving from the research phase to development phase. It's now necessary to prove and to possibly improve the technology competitiveness. Therefore we need a tool able to allow communication between hydrogen producers and electrolysis cell stack designers. Designers seek where their efforts have to focus, for example by searching what are the operating best conditions for HTSE (voltage, temperature). On the contrary, the producer wants to choose the most suitable stack for its needs and under the best conditions: hydrogen has to be produced at the lowest price. Two main constraints have been identified to reach this objective: the tool has to be inserted into a process simulation software and needs to be representative of the cell and stack used technology. These constraints are antagonistic. Making an object model in a process simulation usually involves a highly simplified representation of it. To meet these constraints, we have built a model chain starting from the electrode models and leading to a representative model of the HTSE technology used process. Work and added value of this thesis mainly concern a global and local energy optimization approach. Our model allows at each scale an appropriate analysis of the main phenomena occurring in each object and a quantification of the energy and economic impacts of the technology used. This approach leads to a tool able to achieve the technical and economic optimization of a HTSE production unit. (author) [fr

  19. System Evaluation and Economic Analysis of a Nuclear Reactor Powered High-Temperature Electrolysis Hydrogen-Production Plant

    International Nuclear Information System (INIS)

    Harvego, E.A.; McKellar, M.G.; Sohal, M.S.; O'Brien, J.E.; Herring, J.S.

    2010-01-01

    A reference design for a commercial-scale high-temperature electrolysis (HTE) plant for hydrogen production was developed to provide a basis for comparing the HTE concept with other hydrogen production concepts. The reference plant design is driven by a high-temperature helium-cooled nuclear reactor coupled to a direct Brayton power cycle. The reference design reactor power is 600 MWt, with a primary system pressure of 7.0 MPa, and reactor inlet and outlet fluid temperatures of 540 C and 900 C, respectively. The electrolysis unit used to produce hydrogen includes 4,009,177 cells with a per-cell active area of 225 cm2. The optimized design for the reference hydrogen production plant operates at a system pressure of 5.0 MPa, and utilizes an air-sweep system to remove the excess oxygen that is evolved on the anode (oxygen) side of the electrolyzer. The inlet air for the air-sweep system is compressed to the system operating pressure of 5.0 MPa in a four-stage compressor with intercooling. The alternating current (AC) to direct current (DC) conversion efficiency is 96%. The overall system thermal-to-hydrogen production efficiency (based on the lower heating value of the produced hydrogen) is 47.1% at a hydrogen production rate of 2.356 kg/s. An economic analysis of this plant was performed using the standardized H2A Analysis Methodology developed by the Department of Energy (DOE) Hydrogen Program, and using realistic financial and cost estimating assumptions. The results of the economic analysis demonstrated that the HTE hydrogen production plant driven by a high-temperature helium-cooled nuclear power plant can deliver hydrogen at a competitive cost. A cost of $3.23/kg of hydrogen was calculated assuming an internal rate of return of 10%.

  20. Hydrogen production by water-splitting using heat supplied by a high-temperature reactor

    International Nuclear Information System (INIS)

    Courvoisier, P.; Rastoin, J.; Titiliette, Z.

    1976-01-01

    Some aspects of the use of heat of nuclear origin for the production of hydrogen by water-splitting are considered. General notions pertaining to the yield of chemical cycles are discussed and the heat balance corresponding to two specific processes is evaluated. The possibilities of high temperature reactors, with respect to the coolant temperature levels, are examined from the standpoint of core design and technology of some components. Furthermore, subject to a judicious selection of their characteristics, these reactors can lead to excellent use of nuclear fuel. The coupling of the nuclear reactor with the chemical plant by means of a secondary helium circuit gives rise to the design of an intermediate heat exchanger, which is an important component of the overall installation. (orig.) [de

  1. High-pressure, ambient temperature hydrogen storage in metal-organic frameworks and porous carbon

    Science.gov (United States)

    Beckner, Matthew; Dailly, Anne

    2014-03-01

    We investigated hydrogen storage in micro-porous adsorbents at ambient temperature and pressures up to 320 bar. We measured three benchmark adsorbents: two metal-organic frameworks, Cu3(1,3,5-benzenetricarboxylate)2 [Cu3(btc)2; HKUST-1] and Zn4O(1,3,5-benzenetribenzoate)2 [Zn4O(btb)2; MOF-177], and the activated carbon MSC-30. In this talk, we focus on adsorption enthalpy calculations using a single adsorption isotherm. We use the differential form of the Claussius-Clapeyron equation applied to the Dubinin-Astakhov adsorption model to calculate adsorption enthalpies. Calculation of the adsorption enthalpy in this way gives a temperature independent enthalpy of 5-7 kJ/mol at the lowest coverage for the three materials investigated. Additionally, we discuss the assumptions and corrections that must be made when calculating adsorption isotherms at high-pressure and adsorption enthalpies.

  2. IGSCC growth behaviors of Alloy 690 in hydrogenated high temperature water

    Energy Technology Data Exchange (ETDEWEB)

    Arioka, K.; Yamada, T.; Miyamoto, T.; Terachi, T. [INSS, (Japan)

    2011-07-01

    The rate of growth of stress corrosion cracking (SCC) was measured for cold worked and thermally treated and solution treated Alloy 690 (UNS N06690, CW TT690, CW ST690) in hydrogenated pressurized water reactor (PWR) primary water under static load condition. Three important patterns were observed: First, Intergranular stress corrosion cracking (IGSCC) was observed on both TT and ST690 even in static load condition if materials were heavily cold worked although the rate of SCC growth was much slower than that of CW mill annealed Alloy 600. Furthermore much rapid SCC growth was recognized in 20% CW TT690 than that of 20% CW ST690. This is quite different result in the literature in high temperature caustic solution. Second, in order to assess the role of creep, rates of creep crack growth were measured in air, argon, and hydrogen gas environments using 20% CW TT690, and 20% CW MA600 in the range of temperatures between 360 and 460 C; intergranular creep cracking (IG creep cracking) was observed on the test materials even in air. Similar slope of 1/T-type temperature dependencies on IGSCC and IG creep crack growth were observed on 20% CW TT690. Similar fracture morphologies and similar 1/T-type temperature dependencies suggest that creep is important in the growth of IGSCC of CW TT690 in high temperature water. Third, cavities and pores were observed at grain boundaries near tips of SCC and creep although the size of the cavities and pores of SCC were much smaller than that of creep cracks. Also the population and size of cavities seem to decrease with decreasing test temperature. These results suggest that the difference in the size and population of cavities might be related with the difference in crack growth rate. And the cavities seem to be formed result from collapse of vacancies at grain boundaries as the crack embryo. This result suggests that diffusion of condensation of vacancies in high stressed fields occurs in high temperature water and gas environments

  3. Some problems on materials tests in high temperature hydrogen base gas mixture

    International Nuclear Information System (INIS)

    Shikama, Tatsuo; Tanabe, Tatsuhiko; Fujitsuka, Masakazu; Yoshida, Heitaro; Watanabe, Ryoji

    1980-01-01

    Some problems have been examined on materials tests (creep rupture tests and corrosion tests) in high temperature mixture gas of hydrogen (80%H 2 + 15%CO + 5%CO 2 ) simulating the reducing gas for direct steel making. H 2 , CO, CO 2 and CH 4 in the reducing gas interact with each other at elevated temperature and produce water vapor (H 2 O) and carbon (soot). Carbon deposited on the walls of retorts and the water condensed at pipings of the lower temperature gas outlet causes blocking of gas flow. The gas reactions have been found to be catalyzed by the retort walls, and appropriate selection of the materials for retorts has been found to mitigate the problems caused by water condensation and carbon deposition. Quartz has been recognized to be one of the most promising materials for minimizing the gas reactions. And ceramic coating, namely, BN (born nitride) on the heat resistant superalloy, MO-RE II, has reduced the amounts of water vapor and deposited carbon (sooting) produced by gas reactions and has kept dew points of outlet gas below room temperature. The well known emf (thermo-electromotive force) deterioration of Alumel-Chromel thermocouples in the reducing gases at elevated temperatures has been also found to be prevented by the ceramic (BN) coating. (author)

  4. Hydrogen detonation and detonation transition data from the High-Temperature Combustion Facility

    International Nuclear Information System (INIS)

    Ciccarelli, G.; Boccio, J.L.; Ginsberg, T.; Finfrock, C.; Gerlach, L.; Malliakos, A.

    1995-01-01

    The BNL High-Temperature Combustion Facility (HTCF) is an experimental research tool capable of investigating the effects of initial thermodynamic state on the high-speed combustion characteristic of reactive gas mixtures. The overall experimental program has been designed to provide data to help characterize the influence of elevated gas-mixture temperature (and pressure) on the inherent sensitivity of hydrogen-air-steam mixtures to undergo detonation, on the potential for flames accelerating in these mixtures to transition into detonations, on the effects of gas venting on the flame-accelerating process, on the phenomena of initiation of detonations in these mixtures by jets of hot reactant product,s and on the capability of detonations within a confined space to transmit into another, larger confined space. This paper presents results obtained from the completion of two of the overall test series that was designed to characterize high-speed combustion phenomena in initially high-temperature gas mixtures. These two test series are the intrinsic detonability test series and the deflagration-to-detonation (DDT) test series. A brief description of the facility is provided below

  5. Hydrogen detonation and detonation transition data from the High-Temperature Combustion Facility

    International Nuclear Information System (INIS)

    Ciccarelli, G.; Boccio, J.L.; Ginsberg, T.; Finfrock, C.

    1996-01-01

    The BNL High-Temperature Combustion Facility (HTCF) is an experimental research tool capable of investigating the effects of initial thermodynamic state on the high-speed combustion characteristic of reactive gas mixtures. The overall experimental program has been designed to provide data to help characterize the influence of elevated gas-mixture temperature (and pressure) on the inherent sensitivity of hydrogen-air-steam mixtures to undergo detonation, on the potential for flames accelerating in these mixtures to transition into detonations, on the effects of gas venting on the flame-accelerating process, on the phenomena of initiation of detonations in these mixtures by jets of hot reactant products, and on the capability of detonations within a confined space to transmit into another, larger confined space. This paper presents results obtained from the completion of two of the overall test series that was designed to characterize high-speed combustion phenomena in initially high-temperature gas mixtures. These two test series are the intrinsic detonability test series and the deflagration-to-detonation (DDT) test series. A brief description of the facility is provided below

  6. Detonation cell size measurements in high-temperature hydrogen-air-steam mixtures at the BNL high-temperature combustion facility

    International Nuclear Information System (INIS)

    Ciccarelli, G.; Ginsberg, T.; Boccio, J.L.

    1997-11-01

    The High-Temperature Combustion Facility (HTCF) was designed and constructed with the objective of studying detonation phenomena in mixtures of hydrogen-air-steam at initially high temperatures. The central element of the HTCF is a 27-cm inner-diameter, 21.3-m long cylindrical test vessel capable of being heating to 700K ± 14K. A unique feature of the HTCF is the 'diaphragmless' acetylene-oxygen gas driver which is used to initiate the detonation in the test gas. Cell size measurements have shown that for any hydrogen-air-steam mixture, increasing the initial mixture temperature, in the range of 300K to 650K, while maintaining the initial pressure of 0.1 MPa, decreases the cell size and thus makes the mixture more detonable. The effect of steam dilution on cell size was tested in stoichiometric and off-stoichiometric (e.g., equivalence ratio of 0.5) hydrogen-air mixtures. Increasing the steam dilution in hydrogen-air mixtures at 0.1 MPa initial pressure increases the cell size, irrespective of initial temperature. It is also observed that the desensitizing effect of steam diminished with increased initial temperature. A 1-dimensional, steady-state Zel'dovich, von Neumann, Doring (ZND) model, with full chemical kinetics, has been used to predict cell size for hydrogen-air-steam mixtures at different initial conditions. Qualitatively the model predicts the overall trends observed in the measured cell size versus mixture composition and initial temperature and pressure. It was found that the proportionality constant used to predict detonation cell size from the calculated ZND model reaction zone varies between 10 and 100 depending on the mixture composition and initial temperature. 32 refs., 35 figs

  7. High-temperature hydrogen-air-steam detonation experiments in the BNL small-scale development apparatus

    International Nuclear Information System (INIS)

    Ciccarelli, G.; Ginsberg, T.; Boccio, J.; Economos, C.; Finfrock, C.; Gerlach, L.; Sato, K.

    1994-01-01

    The Small-Scale Development Apparatus (SSDA) was constructed to provide a preliminary set of experimental data to characterize the effect of temperature on the ability of hydrogen-air-steam-mixtures to undergo detonations and, equally important, to support design of the larger-scale High-Temperature Combustion Facility (HTCF) by providing a test bed for solution of a number of high-temperature design and operational problems. The SSDA, the central element of which is 10-cm inside diameter, 6.1-m long tubular test vessel designed to permit detonation experiments at temperatures up to 700K, was employed to study self-sustained detonations in gaseous mixtures of hydrogen, air, and steam at temperature between 300K and 650K at a fixed pressure of 0.1 MPa. Detonation cell size measurements provide clear evidence that the effect of hydrogen-air gas mixture temperature, in the range 300K to 650K, is to decrease cell size and, hence, to increase the sensitivity of the mixture to undergo detonations. The effect of steam content, at any given temperature, is to increase the cell size and, thereby, to decrease the sensitivity of stoichiometric hydrogen-air mixtures. The one-dimensional ZND model does a very good job at predicting the overall trends in the cell size data over the range of hydrogen-air-steam mixture compositions and temperature studied in the experiments. Experiments were conducted to measure the rate of hydrogen oxidation in the absence of ignition sources at temperatures of 500K and 650K, for hydrogen-air mixtures of 15% and 50%, and for a mixture of equimolar hydrogen-air and 30% steam at 650K. The rate of hydrogen oxidation was found to be significant at 650K. Reduction of hydrogen concentration by chemical reaction from 50 to 44% hydrogen, and from 15 to 11% hydrogen, were observed on a time frame of minutes. The DeSoete rate equation predicts the 50% experiment very well, but greatly underestimates the reaction rate of the lean mixtures

  8. Thermodynamic analysis of the efficiency of high-temperature steam electrolysis system for hydrogen production

    Science.gov (United States)

    Mingyi, Liu; Bo, Yu; Jingming, Xu; Jing, Chen

    High-temperature steam electrolysis (HTSE), a reversible process of solid oxide fuel cell (SOFC) in principle, is a promising method for highly efficient large-scale hydrogen production. In our study, the overall efficiency of the HTSE system was calculated through electrochemical and thermodynamic analysis. A thermodynamic model in regards to the efficiency of the HTSE system was established and the quantitative effects of three key parameters, electrical efficiency (η el), electrolysis efficiency (η es), and thermal efficiency (η th) on the overall efficiency (η overall) of the HTSE system were investigated. Results showed that the contribution of η el, η es, η th to the overall efficiency were about 70%, 22%, and 8%, respectively. As temperatures increased from 500 °C to 1000 °C, the effect of η el on η overall decreased gradually and the η es effect remained almost constant, while the η th effect increased gradually. The overall efficiency of the high-temperature gas-cooled reactor (HTGR) coupled with the HTSE system under different conditions was also calculated. With the increase of electrical, electrolysis, and thermal efficiency, the overall efficiencies were anticipated to increase from 33% to a maximum of 59% at 1000 °C, which is over two times higher than that of the conventional alkaline water electrolysis.

  9. High Efficient Reduction of Graphene Oxide via Nascent Hydrogen at Room Temperature

    Directory of Open Access Journals (Sweden)

    Qiqi Zhuo

    2018-02-01

    Full Text Available To develop a green and efficient method to synthesize graphene in relative milder conditions is prerequisite for graphene applications. A chemical reducing method has been developed to high efficiently reduce graphene oxide (GO using Fe2O3 and NH3BH3 as catalyst and reductants, respectively. During the process, environmental and strong reductive nascent hydrogen were generated surrounding the surface of GO sheets by catalyst hydrolysis reaction of NH3BH3 and were used for reduction of GO. The reduction process was studied by ultraviolet absorption spectroscopy, Raman spectroscopy, and Fourier transform infrared spectrum. The structure and morphology of the reduced GO were characterized with scanning electron microscopy and transmission electron microscopy. Compared to metal (Mg/Fe/Zn/Al particles and acid system which also use nascent hydrogen to reduce GO, this method exhibited higher reduction efficiency (43.6%. Also the reduction was carried out at room temperature condition, which is environmentally friendly. As a supercapacitor electrode, the reversible capacity of reduced graphene oxide was 113.8 F g−1 at 1 A g−1 and the capacitance retention still remained at 90% after 200 cycles. This approach provides a new method to reduce GO with high reduction efficiency by green reductant.

  10. High temperature corrosion in the thermochemical hydrogen production from nuclear heat

    International Nuclear Information System (INIS)

    Coen-Porisini, F.; Imarisio, G.

    1976-01-01

    In the production of hydrogen by water decomposition utilizing nuclear heat, a multistep process has to be employed. Water and the intermediate chemical products reach in chemical cycles giving hydrogen and oxygen with regeneration of the primary products used. Three cycles are examined, characterized by the presence of halide compounds and particularly hydracids at temperatures up to 800 0 C. Corrosion tests were carried out in hydrobromic acid, hydrochloric acid, ferric chloride solutions, and hydriodic acid

  11. High performance hydrogen storage from Be-BTB metal-organic framework at room temperature.

    Science.gov (United States)

    Lim, Wei-Xian; Thornton, Aaron W; Hill, Anita J; Cox, Barry J; Hill, James M; Hill, Matthew R

    2013-07-09

    The metal-organic framework beryllium benzene tribenzoate (Be-BTB) has recently been reported to have one of the highest gravimetric hydrogen uptakes at room temperature. Storage at room temperature is one of the key requirements for the practical viability of hydrogen-powered vehicles. Be-BTB has an exceptional 298 K storage capacity of 2.3 wt % hydrogen. This result is surprising given that the low adsorption enthalpy of 5.5 kJ mol(-1). In this work, a combination of atomistic simulation and continuum modeling reveals that the beryllium rings contribute strongly to the hydrogen interaction with the framework. These simulations are extended with a thermodynamic energy optimization (TEO) model to compare the performance of Be-BTB to a compressed H2 tank and benchmark materials MOF-5 and MOF-177 in a MOF-based fuel cell. Our investigation shows that none of the MOF-filled tanks satisfy the United States Department of Energy (DOE) storage targets within the required operating temperatures and pressures. However, the Be-BTB tank delivers the most energy per volume and mass compared to the other material-based storage tanks. The pore size and the framework mass are shown to be contributing factors responsible for the superior room temperature hydrogen adsorption of Be-BTB.

  12. Economic Analysis of the Reference Design for a Nuclear-Driven High-Temperature-Electrolysis Hydrogen Production Plant

    International Nuclear Information System (INIS)

    E. A. Harvego; M. G. McKellar; M. S. Sohal; J. E. O'Brien; J. S. Herring

    2008-01-01

    A reference design for a commercial-scale high-temperature electrolysis (HTE) plant for hydrogen production was developed to provide a basis for comparing the HTE concept with other hydrogen production concepts. The reference plant design is driven by a high-temperature helium-cooled reactor coupled to a direct Brayton power cycle. The reference design reactor power is 600 MWt, with a primary system pressure of 7.0 MPa, and reactor inlet and outlet fluid temperatures of 540 C and 900 C, respectively. The electrolysis unit used to produce hydrogen consists of 4,009,177 cells with a per-cell active area of 225 cm2. A nominal cell area-specific resistance, ASR, value of 0.4 Ohm-cm2 with a current density of 0.25 A/cm2 was used, and isothermal boundary conditions were assumed. The optimized design for the reference hydrogen production plant operates at a system pressure of 5.0 MPa, and utilizes an air-sweep system to remove the excess oxygen that is evolved on the anode side of the electrolyzer. The inlet air for the air-sweep system is compressed to the system operating pressure of 5.0 MPa in a four-stage compressor with intercooling. The alternating current, AC, to direct current, DC, conversion is 96%. The overall system thermal-to-hydrogen production efficiency (based on the low heating value of the produced hydrogen) is 47.12% at a hydrogen production rate of 2.356 kg/s. An economic analysis of the plant was also performed using the H2A Analysis Methodology developed by the Department of Energy (DOE) Hydrogen Program. The results of the economic analysis demonstrated that the HTE hydrogen production plant driven by a high-temperature helium-cooled nuclear power plant can deliver hydrogen at a competitive cost using realistic financial and cost estimating assumptions. A required cost of $3.23 per kg of hydrogen produced was calculated assuming an internal rate of return of 10%. Approximately 73% of this cost ($2.36/kg) is the result of capital costs associated with

  13. Optimized Flow Sheet for a Reference Commercial-Scale Nuclear-Driven High-Temperature Electrolysis Hydrogen Production Plant

    International Nuclear Information System (INIS)

    M. G. McKellar; J. E. O'Brien; E. A. Harvego; J. S. Herring

    2007-01-01

    This report presents results from the development and optimization of a reference commercial scale high-temperature electrolysis (HTE) plant for hydrogen production. The reference plant design is driven by a high-temperature helium-cooled reactor coupled to a direct Brayton power cycle. The reference design reactor power is 600 MWt, with a primary system pressure of 7.0 MPa, and reactor inlet and outlet fluid temperatures of 540 C and 900 C, respectively. The electrolysis unit used to produce hydrogen consists of 4.176 - 10 6 cells with a per-cell active area of 225 cm2. A nominal cell area-specific resistance, ASR, value of 0.4 Ohm-cm2 with a current density of 0.25 A/cm2 was used, and isothermal boundary conditions were assumed. The optimized design for the reference hydrogen production plant operates at a system pressure of 5.0 MPa, and utilizes an air-sweep system to remove the excess oxygen that is evolved on the anode side of the electrolyzer. The inlet air for the air-sweep system is compressed to the system operating pressure of 5.0 MPa in a four-stage compressor with intercooling. The overall system thermal-to-hydrogen production efficiency (based on the low heating value of the produced hydrogen) is 49.07% at a hydrogen production rate of 2.45 kg/s with the high-temperature helium-cooled reactor concept. The information presented in this report is intended to establish an optimized design for the reference nuclear-driven HTE hydrogen production plant so that parameters can be compared with other hydrogen production methods and power cycles to evaluate relative performance characteristics and plant economics

  14. Butterfly valve with metal seals controls flow of hydrogen from cryogenic through high temperatures

    Science.gov (United States)

    Johnson, L. D.

    1967-01-01

    Butterfly valve with metal seals operates over a temperature range of minus 423 degrees to plus 440 degrees F with hydrogen as a medium and in a radiation environment. Media flow is controlled by an internal butterfly disk which is rotated by an actuation shaft.

  15. Polymer-derived microporous ceramics for membranes and sensors for high temperature hydrogen purification and sensing

    Energy Technology Data Exchange (ETDEWEB)

    Prasad, Ravi Mohan

    2012-06-11

    The growing interest in the use of hydrogen as main fuel has increased the need for pure hydrogen (H{sub 2}) production and purification. There are several by-products (CO, H{sub 2}O, CO{sub 2}) associated with the production of hydrogen which might damage the production rate. Therefore, separation of hydrogen from other gases is an important step in the hydrogen production process. If H{sub 2} can be selectively removed from the product side during hydrogen production in membrane reactors, then it would be possible to achieve complete CO conversion in a single-step under high temperature conditions. The main goal of the present work is the high temperature H{sub 2} purification and sensing by applying polymer-derived ceramics. To prove the concept, the microporous SiBCN, Si{sub 3}N{sub 4} and SiCN ceramic membranes have been synthesized by the polymer-pyrolysis route and their performance for the hydrogen separation have been evaluated in tubular membranes as well as in planar chemiresistors. The synthesis of amorphous SiBCN ceramics has been realized through pyrolysis of poly(organoborosilazanes) in argon. Multilayered amorphous SiBCN/{gamma}-Al{sub 2}O{sub 3}/{alpha}-Al{sub 2}O{sub 3} membranes with gradient porosity have been realized and assessed with respect to the thermal stability, pore-size distribution and H{sub 2}/CO permeance. N{sub 2}-adsorption measurement indicates micropores in the range of 0.68-0.73 nm for three-fold SiBCN/{gamma}-Al{sub 2}O{sub 3}/{alpha}-Al{sub 2}O{sub 3} membrane. SEM characterization of three-fold SiBCN/{gamma}-Al{sub 2}O{sub 3}/{alpha}-Al{sub 2}O{sub 3} membrane shows the thickness of SiBCN membrane layer is 2.8 {mu}m; gas permeance measurements of the membrane shows H{sub 2}/CO selectivity of about 10.5 and the H{sub 2} permeance of about 1.05 x 10{sup -8} mol m{sup -2}s{sup -1}Pa{sup -1}. The observed gas permeation properties point out that the transportation of gas molecules through the membrane is governed by both

  16. Hydrogen Production via a High-Efficiency Low-Temperature Reformer

    Energy Technology Data Exchange (ETDEWEB)

    Paul KT Liu; Theo T. Tsotsis

    2006-05-31

    Fuel cells are promoted by the US government as a viable alternative for clean and efficient energy generation. It is anticipated that the fuel cell market will rise if the key technical barriers can be overcome. One of them is certainly fuel processing and purification. Existing fuel reforming processes are energy intensive, extremely complicated and capital intensive; these disadvantages handicap the scale-down of existing reforming process, targeting distributed or on-board/stationary hydrogen production applications. Our project involves the bench-scale demonstration of a high-efficiency low-temperature steam reforming process. Hydrogen production can be operated at 350 to 400ºC with our invention, as opposed to >800ºC of existing reforming. In addition, our proposed process improves the start-up deficiency of conventional reforming due to its low temperature operation. The objective of this project is to demonstrate the invented process concept via a bench scale unit and verify mathematical simulation for future process optimization study. Under this project, we have performed the experimental work to determine the adsorption isotherm, reaction kinetics, and membrane permeances required to perform the process simulation based upon the mathematical model developed by us. A ceramic membrane coated with palladium thin film fabricated by us was employed in this study. The adsorption isotherm for a selected hydrotalcite adsorbent was determined experimentally. Further, the capacity loss under cyclic adsorption/desorption was confirmed to be negligible. Finally a commercial steam reforming catalyst was used to produce the reaction kinetic parameters required for the proposed operating condition. With these input parameters, a mathematical simulation was performed to predict the performance of the invented process. According to our simulation, our invented hybrid process can deliver 35 to 55% methane conversion, in comparison with the 12 and 18-21% conversion of

  17. Hydrogen production by high-temperature gas-cooled reactor. Conceptual design of advanced process heat exchangers of the HTTR-IS hydrogen production system

    International Nuclear Information System (INIS)

    Sakaba, Nariaki; Ohashi, Hirofumi; Sato, Hiroyuki; Hara, Teruo; Kato, Ryoma; Kunitomi, Kazuhiko

    2008-01-01

    Nuclear hydrogen production is necessary in an anticipated hydrogen society that demands a massive quantity of hydrogen without economic disadvantage. Japan Atomic Energy Agency (JAEA) has launched the conceptual design study of a hydrogen production system with a near-term plan to connect it to Japan's first high-temperature gas-cooled reactor HTTR. The candidate hydrogen production system is based on the thermochemical water-splitting iodine sulphur (IS) process.The heat of 10 MWth at approximately 900degC, which can be provided by the secondary helium from the intermediate heat exchanger of the HTTR, is the energy input to the hydrogen production system. In this paper, we describe the recent progresses made in the conceptual design of advanced process heat exchangers of the HTTR-IS hydrogen production system. A new concept of sulphuric acid decomposer is proposed. This involves the integration of three separate functions of sulphuric acid decomposer, sulphur trioxide decomposer, and process heat exchanger. A new mixer-settler type of Bunsen reactor is also designed. This integrates three separate functions of Bunsen reactor, phase separator, and pump. The new concepts are expected to result in improved economics through construction and operation cost reductions because the number of process equipment and complicated connections between the equipment has been substantially reduced. (author)

  18. Highly sensitive work function hydrogen gas sensor based on PdNPs/SiO2/Si structure at room temperature

    Directory of Open Access Journals (Sweden)

    G. Behzadi pour

    Full Text Available In this study, fabrication of highly sensitive PdNPs/SiO2/Si hydrogen gas sensor using experimental and theoretical methods has been investigated. Using chemical method the PdNPs are synthesized and characterized by X-ray diffraction (XRD. The average size of PdNPs is 11 nm. The thickness of the oxide film was 20 nm and the surface of oxide film analyzed using Atomic-force microscopy (AFM. The C-V curve for the PdNPs/SiO2/Si hydrogen gas sensor in 1% hydrogen concentration and at the room temperature has been reported. The response time and recovery time for 1% hydrogen concentration at room temperature were 1.2 s and 10 s respectively. The response (R% for PdNPs/SiO2/Si MOS capacitor hydrogen sensor was 96%. The PdNPs/SiO2/Si MOS capacitor hydrogen sensor showed very fast response and recovery times compared to SWCNTs/PdNPs, graphene/PdNPs, nanorod/PdNPs and nanowire/PdNPs hydrogen gas sensors. Keywords: Sensitive, Oxide film, Capacitive, Resistance

  19. Development status on hydrogen production technology using high-temperature gas-cooled reactor at JAEA, Japan

    International Nuclear Information System (INIS)

    Shiozawa, Shusaku; Ogawa, Masuro; Hino, Ryutaro

    2006-01-01

    The high-temperature gas-cooled reactor (HTGR), which is graphite-moderated and helium-cooled, is attractive due to its unique capability of producing high temperature helium gas and its fully inherent reactor safety. In particular, hydrogen production using the nuclear heat from HTGR (up to 900 deg. C) offers one of the most promising technological solutions to curb the rising level of CO 2 emission and resulting risk of climate change. The interests in HTGR as an advanced nuclear power source for the next generation reactor, therefore, continue to rise. This is represented by the Japanese HTTR (High-Temperature Engineering Test Reactor) Project and the Chinese HTR-10 Project, followed by the international Generation IV development program, US nuclear hydrogen initiative program, EU innovative HTR technology development program, etc. To enhance nuclear energy application to heat process industries, the Japan Atomic Energy Agency (JAEA) has continued extensive efforts for development of hydrogen production system using the nuclear heat from HTGR in the framework of the HTTR Project. The HTTR Project has the objectives of establishing both HTGR technology and heat utilization technology. Using the HTTR constructed at the Oarai Research and Development Center of JAEA, reactor performance and safety demonstration tests have been conducted as planned. The reactor outlet temperature of 950 deg. C was successfully achieved in April 2004. For hydrogen production as heat utilization technology, R and D on thermo-chemical water splitting by the 'Iodine-Sulfur process' (IS process) has been conducted step by step. Proof of the basic IS process was made in 1997 on a lab-scale of hydrogen production of 1 L/h. In 2004, one-week continuous operation of the IS process was successfully demonstrated using a bench-scale apparatus with hydrogen production rate of 31 L/h. Further test using a pilot scale facility with greater hydrogen production rate of 10 - 30 m 3 /h is planned as

  20. Parametric Evaluation of Large-Scale High-Temperature Electrolysis Hydrogen Production Using Different Advanced Nuclear Reactor Heat Sources

    International Nuclear Information System (INIS)

    Harvego, Edwin A.; McKellar, Michael G.; O'Brien, James E.; Herring, J. Stephen

    2009-01-01

    High Temperature Electrolysis (HTE), when coupled to an advanced nuclear reactor capable of operating at reactor outlet temperatures of 800 C to 950 C, has the potential to efficiently produce the large quantities of hydrogen needed to meet future energy and transportation needs. To evaluate the potential benefits of nuclear-driven hydrogen production, the UniSim process analysis software was used to evaluate different reactor concepts coupled to a reference HTE process design concept. The reference HTE concept included an Intermediate Heat Exchanger and intermediate helium loop to separate the reactor primary system from the HTE process loops and additional heat exchangers to transfer reactor heat from the intermediate loop to the HTE process loops. The two process loops consisted of the water/steam loop feeding the cathode side of a HTE electrolysis stack, and the sweep gas loop used to remove oxygen from the anode side. The UniSim model of the process loops included pumps to circulate the working fluids and heat exchangers to recover heat from the oxygen and hydrogen product streams to improve the overall hydrogen production efficiencies. The reference HTE process loop model was coupled to separate UniSim models developed for three different advanced reactor concepts (a high-temperature helium cooled reactor concept and two different supercritical CO2 reactor concepts). Sensitivity studies were then performed to evaluate the affect of reactor outlet temperature on the power cycle efficiency and overall hydrogen production efficiency for each of the reactor power cycles. The results of these sensitivity studies showed that overall power cycle and hydrogen production efficiencies increased with reactor outlet temperature, but the power cycles producing the highest efficiencies varied depending on the temperature range considered

  1. Studies on the permeation of hydrogen through steam generator tubes at high temperatures using an electrochemical method

    International Nuclear Information System (INIS)

    Giraudeau, F.; Yang, L.; Steward, F.R.; DeBouvier, O.

    1998-01-01

    The permeation of hydrogen through steam generator tubes at high temperatures (∼ 300 degrees C) has been studied using an electrochemical technique. With this technique, hydrogen is generated on one side of the tube and monitored on the other side. The time for the hydrogen to reach the other side is used to determine the diffusion coefficient of hydrogen in the tube. Boundary conditions at the entry and exit sides have been investigated separately. Preliminary studies were performed on Stainless Steel 316 and Nickel Alloy 800 to better understand the influence of the solution chemistry on the electrochemical evolution of hydrogen. The surface phenomena effect and the trapping effect are discussed to account for differences observed in the permeation response. The hydrogen permeation through oxides at the exit side has been studied. Two nickel alloys (Alloy 800 and Alloy 600), materials widely used for steam generator tubes, have been investigated. The tubes were prefilmed using two different treatments. The oxides were formed in dry air at high temperatures (300 degrees C to 600 degrees C), or in humid gas at 300 degrees C. The diffusion coefficients at 300 degrees C in Stainless Steel 316 and Alloy 800 were determined to be of the order of 10 -6 - 10 -7 cm 2 /s for the bare metal. This is in agreement with results obtained by gas phase permeation techniques in the literature. (author)

  2. Development of High Temperature SiC Based Hydrogen/Hydrocarbon Sensors with Bond Pads for Packaging

    Science.gov (United States)

    Xu, Jennifer C.; Hunter, Gary W.; Chen, Liangyu; Biagi-Labiosa, Azlin M.; Ward, Benjamin J.; Lukco, Dorothy; Gonzalez, Jose M., III; Lampard, Peter S.; Artale, Michael A.; Hampton, Christopher L.

    2011-01-01

    This paper describes efforts towards the transition of existing high temperature hydrogen and hydrocarbon Schottky diode sensor elements to packaged sensor structures that can be integrated into a testing system. Sensor modifications and the technical challenges involved are discussed. Testing of the sensors at 500 C or above is also presented along with plans for future development.

  3. CH spectroscopy for carbon chemical erosion analysis in high density low temperature hydrogen plasma

    NARCIS (Netherlands)

    Westerhout, J.; Cardozo, N. J. L.; Rapp, J.; van Rooij, G. J.

    2009-01-01

    The CH A-X molecular band is measured upon seeding the hydrogen plasma in the linear plasma generator Pilot-PSI [electron temperature T-e=0.1-2.5 eV and electron density n(e)=(0.5-5) X 10(20) m(-3)] with methane. Calculated inverse photon efficiencies for these conditions range from 3 up to

  4. Continuous high-temperature surveillance instrumentation for Dresden-2 hydrogen water chemistry program

    International Nuclear Information System (INIS)

    Fleming, M.F.; Mitchell, R.A.; Nelson, J.L.

    1987-01-01

    The objective of this program (under EPRI Contract RP1930-11) is to install and operate a high-temperature surveillance instrumentation system capable of monitoring the length of cracks in boiling water reactor (BWR) piping during plant operation. The ability to measure crack growth in BWR power plant piping welds is important to rapidly identify the effectiveness of repairs (such as the Hydrogen Water Chemistry Program). The feasibility of a system capable of continuous ultrasonic instrumentation at 600 0 F (288 0 C) was successfully demonstrated at the Dresden-2 suction line known as N1B. This intergranular stress corrosion cracking (IGSCC) surveillance instrumentation is sound in principal, because it survived on N1B for a time period of more than nine months from April 1985 to January 1986 (the last time data were recorded). The redesigned low-profile transducer system used for this system operated successfully for the same nine-month time period. This low profile transducer fits in the two-inch space normally occupied by insulation. As a result of poor routing of the coaxial cables running from the low-profile transducer to the electrical feed-throughs between the drywell and containment, these cables melted. Other instrument cables nearby were not damaged

  5. Experimental researches on hydrogen generation by aluminum with adding lithium at high temperature

    International Nuclear Information System (INIS)

    Yang, Weijuan; Zhang, Tianyou; Liu, Jianzhong; Wang, Zhihua; Zhou, Junhu; Cen, Kefa

    2015-01-01

    In order to recover the released heat of Al–H_2O reaction and promote the reaction itself, the hydrogen production processes of aluminum with lithium addition in molten state are investigated. Experiments are conducted by both a thermogravimetric analyzer and a special experimental facility at high temperature. The results on both apparatuses show that the addition of Li can promote the reactivity of aluminum with water. Compared with pure aluminum, only 5% of Li content can achieve a great improvement: the H_2 yield increases from 8.7% to 53% and the average H_2 generation rate from 15 to 112 mL min"−"1 g"−"1. With the increase of Li content, H_2 yield is improved distinctly and the period with a high H_2 generation rate is prolonged. In the Al–20%Li case, the H_2 yield of 88% is obtained, and it appears a stable period in which the H_2 generation rate keeps high. When adding lithium, LiAlO_2 appears in the products and the products are made of columnar crystals. The pores with an average size of 17–33 nm in the LiAlO_2 products are manyfold bigger than the pores of alumina, which takes an important role in improving the reactivity of aluminum and water. - Highlights: • The Al–H_2O reaction with Li addition in molten state was researched. • Li addition can achieve a great promotion of H_2 yield and H_2 generation rate. • The Al–20%Li case achieved a H_2 yield of 88%. • With Li addition, LiAlO_2 was detected in the reaction products. • XRD and TEM-EDS results indicated the promoting mechanism of Li.

  6. Line profiles of hydrogenic ions from high-temperature and high-density plasmas

    International Nuclear Information System (INIS)

    Hou Qing; Li Jianming

    1991-01-01

    Applying the Hooper's first-order theory, the authors calculate the static micro-electric field distributions in plasmas containing various multiply-charged ions. The influences of the impurity concentrations on the micro electric field distributions and on the Lyman profiles (n→1) from hydrogenic ions are analysed. Based on the optical-thin line profiles, the radiation transfer equation in sphere plasmas with various optical depths is solved. The results confirm that the opacity-broadening of the line profiles has almost no effect on the separation of Lyman β splitted peaks. Such separation is determined by electric field at which the static micro-electric field distribution has a maximum. The separation can be utilized for spatially resolved and temporally resolved density diagnostic of fusion plasmas

  7. Hydrogen production by high-temperature electrolysis of water vapor steam. Test results obtained with an electrolysis tube

    International Nuclear Information System (INIS)

    Hino, Ryutaro; Miyamoto, Yoshiaki

    1995-01-01

    High-temperature electrolysis of water vapor steam is an advanced hydrogen production process decomposing high temperature steam up to 1,000degC, which applies an electro-chemical reaction reverse to the solid oxide fuel cell. At Japan Atomic Energy Research Institute, laboratory-scale experiments have been conducted using a practical electrolysis tube with 12 electrolysis cells in order to develop heat utilization systems for high-temperature gas-cooled reactors. The electrolysis cells of which electrolyte was yttria-stabilized zirconia were formed on a porous ceramic tube in series by plasma spraying. In the experiments, water steam mixed with argon carrier gas was supplied into the electrolysis tube heated at a constant temperature regulated in the range from 850degC to 950degC, and electrolysis power was supplied by a DC power source. Hydrogen production rate increased with applied voltage and electrolysis temperature; the maximum production rate was 6.9Nl/h at 950degC. Hydrogen production rate was correlated with applied current densities on the basis of experimental data. High energy efficiency was achieved under the applied current density ranging from 80 to 100 mA/cm 2 . (author)

  8. Effects of impurities on hydrogen permeability through palladium alloy membrane at comparatively high pressure and temperature

    International Nuclear Information System (INIS)

    Yoshida, Hiroshi; Konishi, Satoshi; Katsuta, Hiroji; Naruse, Yuji

    1982-02-01

    Palladium alloy membrane method is considered to be a useful technique for fusion reactor fuel purification process. To study the feasibility of this method, the effects of impurities on permeation characteristics of palladium alloy membrane were examined. Experiments were carried out at practical conditions: pressure; 120 - 1200 kPa, temperature; about 700 K. No poisoning effect on hydrogen permeability of commercial Pd-Ag (Au.Ru) alloy was observed for impurities such as NH 3 , CH 4 , CO, CO 2 , O 2 and N 2 , which were mixed with hyper-pure H 2 at low concentration level (10 - 10000 ppm). Deterioration occurred by contamination with oil vapor. However, regeneration of the membrane was easily performed by air baking followed by hydrogen reduction. Chemical reactions in the permeation cell were also examined. (author)

  9. Hydrogen pellet ablation and accelerator by current in high temperature plasmas

    International Nuclear Information System (INIS)

    Kuteev, B.V.

    1995-01-01

    Hydrogen pellet ablation and acceleration by current in high temperature plasmas are analyzed. The present state of ablation theory and experiment is discussed and an ablation model is formulated. This model takes into account the energy distribution of the particles (both electrons and ions) participating in the ablation process, electrostatic effects of the cloud charging and changes of the pellet form during ablation. Without charging the pellet form tends to a shape resembling a lentil while it remains almost spherical if charged. A new algorithm for ablation rate calculations that can be used for an arbitrary initial form of the pellet is described. The results of this kinetic two dimensional approach differ from those of the Parks ablation scaling used in the ITER design by not more than 30%. Plasma shielding effects are not significant in the ablation if strong turbulence in the cloud is taken into account. Acceleration analysis is based on the Braginskii corrected electron distribution function. For the lentil mode of ablation, acceleration is higher than those for the charged mode by a factor of 1.76. The ablation models are compared with the experiments on T-10, JET, TFTR, Heliotron-E and Tore Supra. A sensitivity analysis shows that pellet size and electron temperature are the most significant factors for determination of the penetration length. The available database of penetration lengths is not sufficient for distinguishing between the models. Acceleration for the charged model correlates with experimental data better than that for the lentil mode. The effect of the hot ions is seen on the ablation. Finally, ablation at reactor relevant plasma and pellet parameters is considered. This range of the plasma parameters needs a correction of the ablation scaling as follows: dN/dt ∼ n 0.453 e T 1.72 e r 1.443 p M -0.283 i , where n e and T e are the electron density and temperature, respectively, and r p and M i are the pellet radius and atomic mass

  10. Diffusion characteristics of specific metals at the high temperature hydrogen separation; Diffusionseigenschaften bestimmter Metalle bei der Hochtemperatur-Wasserstoffabtrennung

    Energy Technology Data Exchange (ETDEWEB)

    Schaefer, Christian

    2010-09-07

    This paper evaluates the metals palladium, nickel, niobium, tantalum, titanium and vanadium according to their ability to separate hydrogen at high temperatures. This evaluation is chiefly based on a thorough consideration of the properties of diffusion for these metals. The various known hydrogen permeabilities of the metals in a temperature range from 300 to 800 C, as well as their physical and mechanical properties will be presented consistent with the current state of technology. The theory of hydrogen diffusion in metals and the mathematical basis for the calculation of diffusion will also be shown. In the empirical section of the paper, permeability measurements are taken in a temperature range of 400 to 825 C. After measurement, the formation of the oxide coating on these membranes is examined using a light-optical microscope. The results of these examinations allow a direct comparison of the different permeabilities of the various metals within the temperature range tested, and also allow for a critical evaluation of the oxide coating formed on the membranes. The final part of the paper shows the efficiency of these metals in the context of in-situ hydrogen separation in a biomass reformer. (orig.)

  11. System Evaluation and Life-Cycle Cost Analysis of a Commercial-Scale High-Temperature Electrolysis Hydrogen Production Plant

    Energy Technology Data Exchange (ETDEWEB)

    Edwin A. Harvego; James E. O' Brien; Michael G. McKellar

    2012-11-01

    Results of a system evaluation and lifecycle cost analysis are presented for a commercial-scale high-temperature electrolysis (HTE) central hydrogen production plant. The plant design relies on grid electricity to power the electrolysis process and system components, and industrial natural gas to provide process heat. The HYSYS process analysis software was used to evaluate the reference central plant design capable of producing 50,000 kg/day of hydrogen. The HYSYS software performs mass and energy balances across all components to allow optimization of the design using a detailed process flow sheet and realistic operating conditions specified by the analyst. The lifecycle cost analysis was performed using the H2A analysis methodology developed by the Department of Energy (DOE) Hydrogen Program. This methodology utilizes Microsoft Excel spreadsheet analysis tools that require detailed plant performance information (obtained from HYSYS), along with financial and cost information to calculate lifecycle costs. The results of the lifecycle analyses indicate that for a 10% internal rate of return, a large central commercial-scale hydrogen production plant can produce 50,000 kg/day of hydrogen at an average cost of $2.68/kg. When the cost of carbon sequestration is taken into account, the average cost of hydrogen production increases by $0.40/kg to $3.08/kg.

  12. Effect of high hydrogen content on metallurgical and mechanical properties of zirconium alloy claddings after heat-treatment at high temperature

    International Nuclear Information System (INIS)

    Turque, Isabelle

    2016-01-01

    Under hypothetical loss-of-coolant accident conditions, fuel cladding tubes made of zirconium alloys can be exposed to steam at high temperature (HT, up 1200 C) before being cooled and then quenched in water. In some conditions, after burst occurrence the cladding can rapidly absorb a significant amount of hydrogen (secondary hydriding), up to 3000 wt.ppm locally, during steam exposition at HT. The study deals with the effect, poorly studied up to date, of high contents of hydrogen on the metallurgical and mechanical properties of two zirconium alloys, Zircaloy-4 and M5, during and after cooling from high temperatures, at which zirconium is in its β phase. A specific facility was developed to homogeneously charge in hydrogen up to ∼ 3000 wt.ppm cladding tube samples of several centimeters in length. Phase transformations, chemical element partitioning and hydrogen precipitation during cooling from the β temperature domain of zirconium were studied by using several techniques, for the materials containing up to ∼ 3000 wt.ppm of hydrogen in average: in-situ neutron diffraction upon cooling from 700 C, X-ray diffraction, μ-ERDA, EPMA and electron microscopy in particular. The results were compared to thermodynamic predictions. In order to study the effect of high hydrogen contents on the mechanical behavior of the (prior-)μ phase of zirconium, axial tensile tests were performed at various temperatures between 20 and 700 C upon cooling from the β temperature domain, on samples with mean hydrogen contents up to ∼ 3000 wt.ppm. The results show that metallurgical and mechanical properties of the (prior-)β phase of zirconium alloys strongly depend on temperature and hydrogen content. (author) [fr

  13. Techno-economic study of hydrogen production by high temperature electrolysis and coupling with different thermal energy sources

    International Nuclear Information System (INIS)

    Rivera-Tinoco, R.

    2009-03-01

    This work focuses on the techno-economic study of massive hydrogen production by the High Temperature Electrolysis (HTE) process and also deals with the possibility of producing the steam needed in the process by using different thermal energy sources. Among several sources, those retained in this study are the biomass and domestic waste incineration units, as well as two nuclear reactors (European Pressurised water Reactor - EPR and Sodium Fast Reactor - SFR). Firstly, the technical evaluation of the steam production by each of these sources was carried out. Then, the design and modelling of the equipments composing the process, specially the electrolysers (Solid Oxides Electrolysis Cells), are presented. Finally, the hydrogen production cost for each energy sources coupled with the HTE process is calculated. Moreover, several sensibility studies were performed in order to determine the process key parameter and to evaluate the influence of the unit size effect, the electric energy cost, maintenance, the cells current density, their investment cost and their lifespan on the hydrogen production cost. Our results show that the thermal energy cost is much more influent on the hydrogen production cost than the steam temperature at the outlet stream of the thermal source. It seems also that the key parameters for this process are the electric energy cost and the c ells lifespan. The first one contributes for more than 70% of the hydrogen production cost. From several cell lifespan values, it seems that a 3 year value, rather than 1 year, could lead to a hydrogen production cost reduced on 34%. However, longer lifespan values going from 5 to 10 years would only lead to a 8% reduction on the hydrogen production cost. (author)

  14. Oxidation of Inconel 625 superalloy upon treatment with oxygen or hydrogen plasma at high temperature

    Energy Technology Data Exchange (ETDEWEB)

    Vesel, Alenka; Drenik, Aleksander; Elersic, Kristina; Mozetic, Miran; Kovac, Janez [Jozef Stefan Institute, Jamova 39, SI-1000 Ljubljana (Slovenia); Gyergyek, Tomaz [University of Ljubljana, Faculty of Electrical Engineering, Trzaska 25, SI-1000 Ljubljana (Slovenia); Stockel, Jan; Varju, Jozef; Panek, Radomir [Institute of Plasma Physics, Academy of Sciences of the Czech Republic, Ze Slovankou 3, Praha 8 (Czech Republic); Balat-Pichelin, Marianne, E-mail: marianne.balat@promes.cnrs.fr [PROMES-CNRS Laboratory, 7 rue du four solaire, 66120 Font Romeu Odeillo (France)

    2014-06-01

    Initial stages of Inconel 625 superalloy (Ni{sub 60}Cr{sub 30}Mo{sub 10}Ni{sub 4}Nb{sub 1}) oxidation upon short treatment with gaseous plasma at different temperatures up to about 1600 K were studied. Samples were treated for different periods up to a minute by oxygen or hydrogen plasma created with a microwave discharge in the standing-wave mode at a pressure of 40 Pa and a power 500 W. Simultaneous heating of the samples was realized by focusing concentrated solar radiation from a 5 kW solar furnace directly onto the samples. The morphological changes upon treatment were monitored using scanning electron microscopy, compositional depth profiling was performed using Auger electron spectroscopy, while structural changes were determined by X-ray diffraction. The treatment in oxygen plasma caused formation of metal oxide clusters of three dimensional crystallites initially rich in nickel oxide with the increasing chromium oxide content as the temperature was increasing. At about 1100 K iron and niobium oxides prevailed on the surface causing a drop of the material emissivity at 5 μm. Simultaneously the NiCr{sub 2}O{sub 4} compound started growing at the interface between the oxide film and bulk alloy and the compound persisted up to temperatures close to the Inconel melting point. Intensive migration of minority alloying elements such as Fe and Ti was observed at 1600 K forming mixed surface oxides of sub-micrometer dimensions. The treatment in hydrogen plasma with small admixture of water vapor did not cause much modification unless the temperature was close to the melting point. At such conditions aluminum segregated on the surface and formed well-defined Al{sub 2}O{sub 3} crystals.

  15. Oxidation of Inconel 625 superalloy upon treatment with oxygen or hydrogen plasma at high temperature

    Science.gov (United States)

    Vesel, Alenka; Drenik, Aleksander; Elersic, Kristina; Mozetic, Miran; Kovac, Janez; Gyergyek, Tomaz; Stockel, Jan; Varju, Jozef; Panek, Radomir; Balat-Pichelin, Marianne

    2014-06-01

    Initial stages of Inconel 625 superalloy (Ni60Cr30Mo10Ni4Nb1) oxidation upon short treatment with gaseous plasma at different temperatures up to about 1600 K were studied. Samples were treated for different periods up to a minute by oxygen or hydrogen plasma created with a microwave discharge in the standing-wave mode at a pressure of 40 Pa and a power 500 W. Simultaneous heating of the samples was realized by focusing concentrated solar radiation from a 5 kW solar furnace directly onto the samples. The morphological changes upon treatment were monitored using scanning electron microscopy, compositional depth profiling was performed using Auger electron spectroscopy, while structural changes were determined by X-ray diffraction. The treatment in oxygen plasma caused formation of metal oxide clusters of three dimensional crystallites initially rich in nickel oxide with the increasing chromium oxide content as the temperature was increasing. At about 1100 K iron and niobium oxides prevailed on the surface causing a drop of the material emissivity at 5 μm. Simultaneously the NiCr2O4 compound started growing at the interface between the oxide film and bulk alloy and the compound persisted up to temperatures close to the Inconel melting point. Intensive migration of minority alloying elements such as Fe and Ti was observed at 1600 K forming mixed surface oxides of sub-micrometer dimensions. The treatment in hydrogen plasma with small admixture of water vapor did not cause much modification unless the temperature was close to the melting point. At such conditions aluminum segregated on the surface and formed well-defined Al2O3 crystals.

  16. High and rapid hydrogen release from thermolysis of ammonia borane near PEM fuel cell operating temperature

    Science.gov (United States)

    Varma, Arvind; Hwang, Hyun Tae; Al-Kukhun, Ahmad

    2016-11-15

    A system for generating and purifying hydrogen. To generate hydrogen, the system includes inlets configured to receive a hydrogen carrier and an inert insulator, a mixing chamber configured to combine the hydrogen carrier and the inert insulator, a heat exchanger configured to apply heat to the mixture of hydrogen carrier and the inert insulator, wherein the applied heat results in the generation of hydrogen from the hydrogen carrier, and an outlet configured to release the generated hydrogen. To purify hydrogen, the system includes a primary inlet to receive a starting material and an ammonia filtration subassembly, which may include an absorption column configured to absorb the ammonia into water for providing purified hydrogen at a first purity level. The ammonia filtration subassembly may also include an adsorbent member configured to adsorb ammonia from the starting material into an adsorbent for providing purified hydrogen at a second purity level.

  17. Effect of Atomic Hydrogen on Preparation of Highly Moisture-Resistive SiNx Films at Low Substrate Temperatures

    Science.gov (United States)

    Heya, Akira; Niki, Toshikazu; Takano, Masahiro; Yonezawa, Yasuto; Minamikawa, Toshiharu; Muroi, Susumu; Minami, Shigehira; Izumi, Akira; Masuda, Atsushi; Umemoto, Hironobu; Matsumura, Hideki

    2004-12-01

    Highly moisture-resistive SiNx films on a Si substrate are obtained at substrate temperatures of 80°C by catalytic chemical vapor deposition (Cat-CVD) using a source gas with H2. Atomic hydrogen effected the selective etching of a weak-bond regions and an increase in atomic density induced by the energy of the surface reaction. It is concluded that Cat-CVD using H2 is a promising candidate for the fabrication of highly moisture-resistive SiNx films at low temperatures.

  18. Life cycle assessment of hydrogen production from S-I thermochemical process coupled to a high temperature gas reactor

    Energy Technology Data Exchange (ETDEWEB)

    Giraldi, M. R.; Francois, J. L.; Castro-Uriegas, D. [Departamento de Sistemas Energeticos, Facultad de Ingenieria, Universidad Nacional Autonoma de Mexico, Paseo Cuauhnahuac No. 8532, Col. Progreso, C.P. 62550, Jiutepec, Morelos (Mexico)

    2012-07-01

    The purpose of this paper is to quantify the greenhouse gas (GHG) emissions associated to the hydrogen produced by the sulfur-iodine thermochemical process, coupled to a high temperature nuclear reactor, and to compare the results with other life cycle analysis (LCA) studies on hydrogen production technologies, both conventional and emerging. The LCA tool was used to quantify the impacts associated with climate change. The product system was defined by the following steps: (i) extraction and manufacturing of raw materials (upstream flows), (U) external energy supplied to the system, (iii) nuclear power plant, and (iv) hydrogen production plant. Particular attention was focused to those processes where there was limited information from literature about inventory data, as the TRISO fuel manufacture, and the production of iodine. The results show that the electric power, supplied to the hydrogen plant, is a sensitive parameter for GHG emissions. When the nuclear power plant supplied the electrical power, low GHG emissions were obtained. These results improve those reported by conventional hydrogen production methods, such as steam reforming. (authors)

  19. High-temperature hydrogenation of pure and silver-decorated titanate nanotubes to increase their solar absorbance for photocatalytic applications

    Energy Technology Data Exchange (ETDEWEB)

    Plodinec, Milivoj [Ruđer Bošković Institute, Bijenička 54, HR-1002 Zagreb (Croatia); Gajović, Andreja, E-mail: gajovic@irb.hr [Ruđer Bošković Institute, Bijenička 54, HR-1002 Zagreb (Croatia); Jakša, Gregor; Žagar, Kristina; Čeh, Miran [Institute Jožef Stefan, Jamova 39, 1000 Ljubljana (Slovenia)

    2014-04-05

    Graphical abstract: The aim of the work is to study how annealing in a reducing atmosphere of titanate nanotubes (TiNT) and Ag decorated titanate nanotubes (TiNT@Ag) influenced on their structure, morphology, phase transitions, UV–ViS-NIR absorbance and photocatalytic activity. An increase of photocatalytic activity after a heat treatment in a reducing atmosphere was observed in the TiNT and TiNT@Ag. We found that the hydrogenated TiNT@Ag samples (TiNT@Ag-HA) had a two-times higher photodegradation impact on the caffeine than the TiNT samples, which is a consequence of the increased absorption of visible light and the synergetic effects between the silver and the TiO{sub 2} nanoparticles that increase the efficiency of the formation of electron–hole pairs and the charge transfer to the surface of the nanoparticles. -- Highlights: • Titanate nanotubes with and without Ag nanoparticles were hydrogenated at 550 °C. • TiO{sub 2} nanostructures obtained by hydrogenation have core–shell structure. • Hydrogenated samples show absorption in the visible spectral region. • Hydrogenated Ag decorated sample show stronger absorption in visible than in UV. • Photocatalytic efficiency is improved by hydrogenation and by Ag nanoparticles. -- Abstract: Titanate nanotubes (TiNTs) and silver-decorated titanate nanotubes (TiNTs@Ag) were synthesized using the hydrothermal method. In the decorated nanotubes the silver particles were obtained by the photoreduction of AgNO{sub 3} under UV light. Pure and Ag-decorated nanotubes were high-temperature heat treated at 550 °C in a hydrogen atmosphere and the “core–shell”-structured TiO{sub 2} nanoparticles were formed. For the structural characterization of all the titanate nanostructures we used conventional and analytical transmission electron microscopy (TEM) techniques, X-ray diffraction (XRD) and Raman spectroscopy. The Ag-decorated titanate nanostructures were additionally studied by X-ray photo

  20. Thermodynamic diagrams for high temperature plasmas of air, air-carbon, carbon-hydrogen mixtures, and argon

    CERN Document Server

    Kroepelin, H; Hoffmann, K-U

    2013-01-01

    Thermodynamic Diagrams for High Temperature Plasmas of Air, Air-Carbon, Carbon-Hydrogen Mixtures, and Argon provides information relating to the properties of equilibrium gas plasmas formed from hydrocarbons, from air without argon, from pure argon, and from mixtures of air and carbon at various compositions, temperatures and pressures. The data are presented in graphical rather than tabular form to provide a clearer picture of the plasma processes investigated. This book is composed of four chapters, and begins with the introduction to the characteristics of plasmas, with emphasis on their th

  1. Increase the threshold voltage of high voltage GaN transistors by low temperature atomic hydrogen treatment

    Energy Technology Data Exchange (ETDEWEB)

    Erofeev, E. V., E-mail: erofeev@micran.ru [Tomsk State University of Control Systems and Radioelectronics, Research Institute of Electrical-Communication Systems (Russian Federation); Fedin, I. V.; Kutkov, I. V. [Research and Production Company “Micran” (Russian Federation); Yuryev, Yu. N. [National Research Tomsk Polytechnic University, Institute of Physics and Technology (Russian Federation)

    2017-02-15

    High-electron-mobility transistors (HEMTs) based on AlGaN/GaN epitaxial heterostructures are a promising element base for the fabrication of high voltage electronic devices of the next generation. This is caused by both the high mobility of charge carriers in the transistor channel and the high electric strength of the material, which makes it possible to attain high breakdown voltages. For use in high-power switches, normally off-mode GaN transistors operating under enhancement conditions are required. To fabricate normally off GaN transistors, one most frequently uses a subgate region based on magnesium-doped p-GaN. However, optimization of the p-GaN epitaxial-layer thickness and the doping level makes it possible to attain a threshold voltage of GaN transistors close to V{sub th} = +2 V. In this study, it is shown that the use of low temperature treatment in an atomic hydrogen flow for the p-GaN-based subgate region before the deposition of gate-metallization layers makes it possible to increase the transistor threshold voltage to V{sub th} = +3.5 V. The effects under observation can be caused by the formation of a dipole layer on the p-GaN surface induced by the effect of atomic hydrogen. The heat treatment of hydrogen-treated GaN transistors in a nitrogen environment at a temperature of T = 250°C for 12 h reveals no degradation of the transistor’s electrical parameters, which can be caused by the formation of a thermally stable dipole layer at the metal/p-GaN interface as a result of hydrogenation.

  2. Increase the threshold voltage of high voltage GaN transistors by low temperature atomic hydrogen treatment

    International Nuclear Information System (INIS)

    Erofeev, E. V.; Fedin, I. V.; Kutkov, I. V.; Yuryev, Yu. N.

    2017-01-01

    High-electron-mobility transistors (HEMTs) based on AlGaN/GaN epitaxial heterostructures are a promising element base for the fabrication of high voltage electronic devices of the next generation. This is caused by both the high mobility of charge carriers in the transistor channel and the high electric strength of the material, which makes it possible to attain high breakdown voltages. For use in high-power switches, normally off-mode GaN transistors operating under enhancement conditions are required. To fabricate normally off GaN transistors, one most frequently uses a subgate region based on magnesium-doped p-GaN. However, optimization of the p-GaN epitaxial-layer thickness and the doping level makes it possible to attain a threshold voltage of GaN transistors close to V_t_h = +2 V. In this study, it is shown that the use of low temperature treatment in an atomic hydrogen flow for the p-GaN-based subgate region before the deposition of gate-metallization layers makes it possible to increase the transistor threshold voltage to V_t_h = +3.5 V. The effects under observation can be caused by the formation of a dipole layer on the p-GaN surface induced by the effect of atomic hydrogen. The heat treatment of hydrogen-treated GaN transistors in a nitrogen environment at a temperature of T = 250°C for 12 h reveals no degradation of the transistor’s electrical parameters, which can be caused by the formation of a thermally stable dipole layer at the metal/p-GaN interface as a result of hydrogenation.

  3. Hydrogen separation from high temperature CO-containing syn-gas flow using molecular ceramic membranes

    Energy Technology Data Exchange (ETDEWEB)

    Soudarev, A.; Konakov, G.; Souryaninov, A.; Molchanov, A. [Boyko Research Engineering Ceramic Heat Engines Center Ltd., St. Petersburg (Russian Federation); Lelait, L.; Stevens, P.H. [European Inst. for Power Studies, Karlsruhe (Germany)

    2006-07-01

    Poisoning of the platinum (Pt) metals used as catalysts for proton exchange membrane fuel cells (PEMFCs) can negatively impact on PEMFC operation efficiency. In order to address this issue, a supply of hydrogen with a carbon monoxide (CO) admixtures is required. This paper provided details of a new type of molecular ceramic membrane (MCM) that allows the separation of hydrogen (H{sub 2}) from the hydrocarbon fuel reforming products that contain CO and has higher temperature and pressure capacity than other membranes. After various tests, alumo-magnesium spinel (AMS) was selected as the most promising porous material for the ceramic multi-layer membrane. The crystalline structure of the AMS showed good thermo-dynamic stability during tests that ranged between 20 and 1400 degrees C, as well as a chemical resistance relative to the effects of the aggressive fuel cell environment, and no exposure to the oxidation-recovery processes in the CO and H{sub 2} flow. The macroporous substrate of the AMS and the membrane selection layers have the same composition. The formation of the carrier was conducted by a semi-dry molding on a hydraulic press. Formation of the nano-porous structure in the carrier macro-pores by the polysilicon acid sol solution treatment allowed the synthesis of the amorphous silica and crystobalite crystals with a developed surface and nano-dimension subporosity. Test results have shown that the MCM has optimum penetrability and selectivity values as well as admissible thermo-mechanical properties. H{sub 2} flow through the membrane was 1.5-1.7 times greater than the CO flow. It was concluded that the AMS-based membrane devices will increase the efficiency of the PEMFC power plants and reduce their degradation capacity. 2 refs., 1 tab., 1 fig.

  4. On the problem of safe usage of 12MKh steel at elevated temperatures and high hydrogen pressures

    International Nuclear Information System (INIS)

    Archakov, Yu.I.; Teslya, B.M.

    1982-01-01

    The behaviour of the 12MKh steel in hydrogen at pressures of 4-100 MPa and temperatures of 450-600 deg C has been investigated to study the regularities of hydrogen corrosion process. The samples are held in hydrogen under all-round compression in autoclaves with subsequent determination of mechanical properties, carbon content and microstructure. Dependencies of time to begining of intensive embrittlement under given conditions are found. The empiric equation for the calculation of time to beginning of hydrogen corrosion is derived, the safe usage of the 12MKh steel at different temperatures and pressures are determined

  5. Production analysis of methanol and hydrogen of a modificated blast furnace gas using nuclear energy of the high temperature reactor

    International Nuclear Information System (INIS)

    Peschel, W.

    1985-12-01

    Modern blast furnaces are operated with a coke ration of 500 kg/t pig iron. The increase of the coke ratio to 1000 kg/t pig iron raises the content of carbon monoxide and hydrogen in the blast furnace gas. On the basis of a blast furnace gas modificated in such a way, the production of methanol and hydrogen is investigated under the coupling of current and process heat from the high temperature reactor. Moreover the different variants are discussed, for which respectively a material and energetic balance as well as an estimation of the production costs is performed. Regarding the subsequent treatment of the blast furnace gas it turns out favourably in principle to operate the blast furnace with a nitrogen-free wind consisting only of oxygen and steam. The production costs show a strong dependence on the raw material costs, whose influence is shown in a nomograph. (orig.) [de

  6. Hydrogen production system based on high temperature gas cooled reactor energy using the sulfur-iodine (SI) thermochemical water splitting cycle

    International Nuclear Information System (INIS)

    Garcia, L.; Gonzalez, D.

    2011-01-01

    Hydrogen production from water using nuclear energy offers one of the most attractive zero-emission energy strategies and the only one that is practical on a substantial scale. Recently, strong interest is seen in hydrogen production using heat of a high-temperature gas-cooled reactor. The high-temperature characteristics of the modular helium reactor (MHR) make it a strong candidate for producing hydrogen using thermochemical or high-temperature electrolysis (HTE) processes. Eventually it could be also employ a high-temperature gas-cooled reactor (HTGR), which is particularly attractive because it has unique capability, among potential future generation nuclear power options, to produce high-temperature heat ideally suited for nuclear-heated hydrogen production. Using heat from nuclear reactors to drive a sulfur-iodine (SI) thermochemical hydrogen production process has been interest of many laboratories in the world. One of the promising approaches to produce large quantity of hydrogen in an efficient way using the nuclear energy is the sulfur-iodine (SI) thermochemical water splitting cycle. Among the thermochemical cycles, the sulfur iodine process remains a very promising solution in matter of efficiency and cost. This work provides a pre-conceptual design description of a SI-Based H2-Nuclear Reactor plant. Software based on chemical process simulation (CPS) was used to simulate the thermochemical water splitting cycle Sulfur-Iodine for hydrogen production. (Author)

  7. Effects of Iodide and Hydrogen Peroxide on Measuring High Temperature pH in Various Lithium Borate Buffer Solutions

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Jae Sik; Yun, Myung Hee; Yeon, Jei Won; Song, Kyu Seok [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2008-10-15

    In a reactor coolant system of nuclear power plants, the need for reliable high temperature pH electrodes has resulted from interests in the corrosion and corrosion product behaviors of the structural materials in a high temperature coolant system. In developing the electrodes for measuring the high temperature pH of aqueous solutions, it is necessary to note two major problems: the chemical stability of an electrode against other chemical impurities, and an electrode's integrity as the temperature and pressure are varied between operational extremes. Over the past decade Macdonald et al. and Danielson et al. have developed many ceramic membrane pH electrodes based on a yttrium stabilized zirconium oxide. However, there are still many experimental difficulties associated with the problems in obtaining electrochemical information across different pressure boundaries and against many kinds of chemical impurities caused by the radiolysis of water and the leakage of a fuel clad. In the present work, we investigated the effects of the environmental factors on a high temperature pH. The selected environmental factors are as follows: system pressure, and chemical species such as iodide and hydrogen peroxide ions.

  8. High pressure apparatus for hydrogen isotopes to pressures of 345 MPa (50,000 psi) and temperatures of 12000C

    International Nuclear Information System (INIS)

    Lakner, J.F.

    1977-01-01

    A functional new high pressure, high temperature apparatus for hydrogen isotopes uses an internally heated pressure vessel within a larger pressure vessel. The pressure capability is 345 MPa (50 K psi) at 1200 0 C. The gas pressure inside the internal vessel is balanced with gas pressure in the external vessel. The internal vessel is attached to a closure and is also the sample container. Our design allows thin-walled internal vessel construction and keeps the sample from ''seeing'' the furnace or other extraneous environment. The sample container together with the closure can easily be removed and loaded under argon using standard glove-box procedures. The small volume of the inner vessel permits small volumes of gas to be used, thus increasing the sensitivity during pressure-volume-temperature (PVT) work

  9. Advanced High-Temperature Reactor for Production of Electricity and Hydrogen: Molten-Salt-Coolant, Graphite-Coated-Particle-Fuel

    International Nuclear Information System (INIS)

    Forsberg, C.W.

    2002-01-01

    The objective of the Advanced High-Temperature Reactor (AHTR) is to provide the very high temperatures necessary to enable low-cost (1) efficient thermochemical production of hydrogen and (2) efficient production of electricity. The proposed AHTR uses coated-particle graphite fuel similar to the fuel used in modular high-temperature gas-cooled reactors (MHTGRs), such as the General Atomics gas turbine-modular helium reactor (GT-MHR). However, unlike the MHTGRs, the AHTR uses a molten salt coolant with a pool configuration, similar to that of the PRISM liquid metal reactor. A multi-reheat helium Brayton (gas-turbine) cycle, with efficiencies >50%, is used to produce electricity. This approach (1) minimizes requirements for new technology development and (2) results in an advanced reactor concept that operates at essentially ambient pressures and at very high temperatures. The low-pressure molten-salt coolant, with its high heat capacity and natural circulation heat transfer capability, creates the potential for (1) exceptionally robust safety (including passive decay-heat removal) and (2) allows scaling to large reactor sizes [∼1000 Mw(e)] with passive safety systems to provide the potential for improved economics

  10. Nickel brittling by hydrogen. Temperature effect

    International Nuclear Information System (INIS)

    Lapitz, P.A; Fernandez, S; Alvarez, M.G

    2006-01-01

    The results of a study on the effect of different variables on the susceptibility to brittling by hydrogen and the velocity of propagation of fissures in nickel wire (99.7% purity) are described. The hydrogen load was carried out by cathodic polarization in H 2 SO 4 0.5m solution. The susceptibility to brittling by hydrogen was determined with traction tests at slow deformation speed and constant cathodic potential, and the later observation of the fracture surface by scanning electron microscopy. The variables studied were: applied cathodic overpower, speed of initial deformation and temperature. The results showed that the speed of fissure propagation in the nickel by brittleness from hydrogen is a function of the applied potential and the speed of deformation used. Without tension, the hydrogen load by cathodic polarization at room temperature leads to the formation of cavities similar to those observed when the hydrogenation is performed in the presence of gaseous hydrogen at high pressure and temperature (CW)

  11. Modification of the properties of Pt-Al/sub 2/O/sub 3/ catalysts by hydrogen at high temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Menon, P.G.; Froment, G.F.

    1979-08-01

    Pulse reactor studies were performed on the hydrogenolysis of n-pentane and n-hexane at 400/sup 0/C on two commercial reforming catalysts that contained 0.6 and 0.75% platinum on alumina, respectively, and which were calcined in air at 500/sup 0/C, followed by hydrogen-reduction at 400/sup 0/-600/sup 0/C. On catalysts reduced at 400/sup 0/C, hydrogenolysis was the main reaction; with increasing reducing temperature, hydrogenolysis was suppressed and isomerization selectivity increased; at 550/sup 0/C pretreatment temperature, hydrogenolysis was near zero. This selective catalyst deactivation was reversed by oxidizing the catalyst in air at 500/sup 0/C in a similar manner as previously found for sulfided and chlorided catalysts. Temperature-programed desorption of hydrogen adsorbed at 20/sup 0/-600/sup 0/C revealed that the higher the adsorption temperature, the higher the temperature of the hydrogen desorption peaks: the hydrogen adsorbed below 400/sup 0/C desorbed mainly at 50/sup 0/-300/sup 0/C, but the hydrogen adsorbed at higher temperatures desorbed at 300/sup 0/-500/sup 0/C. Apparently, two types of hydrogen adsorb in the two temperature regions, of which the more strongly adsorbed type inhibits hydrogenolysis but not isomerization.

  12. HYBRID SULFUR CYCLE FLOWSHEETS FOR HYDROGEN PRODUCTION USING HIGH-TEMPERATURE GAS-COOLED REACTORS

    Energy Technology Data Exchange (ETDEWEB)

    Gorensek, M.

    2011-07-06

    Two hybrid sulfur (HyS) cycle process flowsheets intended for use with high-temperature gas-cooled reactors (HTGRs) are presented. The flowsheets were developed for the Next Generation Nuclear Plant (NGNP) program, and couple a proton exchange membrane (PEM) electrolyzer for the SO2-depolarized electrolysis step with a silicon carbide bayonet reactor for the high-temperature decomposition step. One presumes an HTGR reactor outlet temperature (ROT) of 950 C, the other 750 C. Performance was improved (over earlier flowsheets) by assuming that use of a more acid-tolerant PEM, like acid-doped poly[2,2'-(m-phenylene)-5,5'-bibenzimidazole] (PBI), instead of Nafion{reg_sign}, would allow higher anolyte acid concentrations. Lower ROT was accommodated by adding a direct contact exchange/quench column upstream from the bayonet reactor and dropping the decomposition pressure. Aspen Plus was used to develop material and energy balances. A net thermal efficiency of 44.0% to 47.6%, higher heating value basis is projected for the 950 C case, dropping to 39.9% for the 750 C case.

  13. Microstructure and high-temperature tribological properties of Si-doped hydrogenated diamond-like carbon films

    Science.gov (United States)

    Zhang, Teng Fei; Wan, Zhi Xin; Ding, Ji Cheng; Zhang, Shihong; Wang, Qi Min; Kim, Kwang Ho

    2018-03-01

    Si-doped DLC films have attracted great attention for use in tribological applications. However, their high-temperature tribological properties remain less investigated, especially in harsh oxidative working conditions. In this study, Si-doped hydrogenated DLC films with various Si content were synthesized and the effects of the addition of Si on the microstructural, mechanical and high-temperature tribological properties of the films were investigated. The results indicate that Si doping leads to an obvious increase in the sp3/sp2 ratio of DLC films, likely due to the silicon atoms preferentially substitute the sp2-hybridized carbon atoms and augment the number of sp3 sites. With Si doping, the mechanical properties, including hardness and adhesion strength, were improved, while the residual stress of the DLC films was reduced. The addition of Si leads to higher thermal and mechanical stability of DLC films because the Si atoms inhibit the graphitization of the films at an elevated temperature. Better high-temperature tribological properties of the Si-DLC films under oxidative conditions were observed, which can be attributed to the enhanced thermal stability and formation of a Si-containing lubricant layer on the surfaces of the wear tracks. The nano-wear resistance of the DLC films was also improved by Si doping.

  14. Safety conditions of using structural steels under high temperature and pressures in hydrogen containing environment

    International Nuclear Information System (INIS)

    Asviyan, M.B.

    1984-01-01

    The method for establishing full-strength conditions was suggested on the base of results of creep-rupture test of tube samples under hydrogen pressure and according to permissible stresses in neutral medium. Applicability of the method was considered taking St3 and 12KhM steels as examples. It was shown that the use of suggested dependences and special efficiency factors enables to forecast endurance limit for the given steel grade and assigned partial hydrogen pressure without labour-intensive test conducting

  15. Two photon emission by hydrogen-like atoms in high temperature plasmas

    International Nuclear Information System (INIS)

    Costescu, A.; Manzatu, I.; Dinu, C.; Mihailescu, I.N.

    1981-08-01

    New exact solutions and a rather simple polynomial expression of the power emitted in the two photon transition from a metastable 2s state to the ground state of a hydrogen-like atom were infered with the aid of the Coulomb Green's function method. It was shown that the two photon decay represents under certain circumstances a significant power loss mechanism. (authors)

  16. The muon spin response to intermittent hyperfine interaction: modelling the high-temperature electrical activity of hydrogen in silicon

    International Nuclear Information System (INIS)

    Lord, J S; Cox, S F J; Charlton, M; Werf, D P Van der; Lichti, R L; Amato, A

    2004-01-01

    At temperatures above 600 K in silicon, unlike at lower temperatures, the partitioning of muonium between its neutral paramagnetic states and its charged or electronically diamagnetic states corresponds closely to thermodynamic equilibrium. The individual charge states are short lived, with many cycles of carrier capture and release occurring within the muon lifetime. The resultant intermittent hyperfine interaction depolarizes the muons strongly, with longitudinal and transverse relaxation rates remaining distinct up to about 700 K but becoming equal at still higher temperatures. Data up to 900 K are presented and interpreted. The muon spin rotation spectrum in transverse magnetic fields, although collapsed to a single broad line in this charge exchange regime, is shifted substantially from the muon Larmor frequency, the shift being non-linear in field and only in small part due to electron polarization. A new density matrix treatment shows how all three observables can be accounted for with a consistent set of transition rates. These in turn may be interpreted in terms of effective donor and acceptor energy levels appropriate to this high-temperature regime, confirming negative-U behaviour and providing the first estimate, for muonium, of this elusive parameter. At temperatures where passivation complexes are dissociated, these findings provide a guide to, and microscopic models for, the electrical activity of hydrogen

  17. PALLADIUM/COPPER ALLOY COMPOSITE MEMBRANES FOR HIGH TEMPERATURE HYDROGEN SEPARATION FROM COAL-DERIVED GAS STREAMS; F

    International Nuclear Information System (INIS)

    J. Douglas Way; Robert L. McCormick

    2001-01-01

    Recent advances have shown that Pd-Cu composite membranes are not susceptible to the mechanical, embrittlement, and poisoning problems that have prevented widespread industrial use of Pd for high temperature H(sub 2) separation. These membranes consist of a thin ((approx)10(micro)m) film of metal deposited on the inner surface of a porous metal or ceramic tube. Based on preliminary results, thin Pd(sub 60)Cu(sub 40) films are expected to exhibit hydrogen flux up to ten times larger than commercial polymer membranes for H(sub 2) separation, and resist poisoning by H(sub 2)S and other sulfur compounds typical of coal gas. Similar Pd-membranes have been operated at temperatures as high as 750 C. The overall objective of the proposed project is to demonstrate the feasibility of using sequential electroless plating to fabricate Pd(sub 60)Cu(sub 40) alloy membranes on porous supports for H(sub 2) separation. These following advantages of these membranes for processing of coal-derived gas will be demonstrated: High H(sub 2) flux; Sulfur tolerant, even at very high total sulfur levels (1000 ppm); Operation at temperatures well above 500 C; and Resistance to embrittlement and degradation by thermal cycling. The proposed research plan is designed to providing a fundamental understanding of: Factors important in membrane fabrication; Optimization of membrane structure and composition; Effect of temperature, pressure, and gas composition on H(sub 2) flux and membrane selectivity; and How this membrane technology can be integrated in coal gasification-fuel cell systems

  18. Distribution of deuterium and hydrogen in Zr and Ti foil assemblies under the action of a pulsed deuterium high-temperature plasma

    Science.gov (United States)

    Bondarenko, G. G.; Volobuev, I. V.; Eriskin, A. A.; Kobzev, A. P.; Nikulin, V. Ya.; Peregudova, E. N.; Silin, P. V.; Borovitskaya, I. V.

    2017-09-01

    Deuteron and proton elastic recoil detection analysis is used to study the accumulation and redistribution of deuterium and hydrogen in assemblies of two high-pure zirconium or titanium foils upon pulsed action of high-temperature deuterium plasma (PHTDP) in a plasma-focus installation PF-4. It is noted that, under the action of PHTDP, an implanted deuterium and hydrogen gas impurity are redistributed in the irradiated foils in large depths, which are significantly larger than the deuterium ion free paths (at their maximum velocity to 108 cm/s). The observed phenomenon is attributed to the carrying out of implanted deuterium and hydrogen under the action of powerful shock waves formed in the metallic foils under the action of PHTDP and/or the acceleration of diffusion of deuterium and hydrogen atoms under the action of a compression-rarefaction shock wave at the shock wave front with the redistribution of deuterium and hydrogen to large depths.

  19. A low-temperature partial-oxidation-methanol micro reformer with high fuel conversion rate and hydrogen production yield

    International Nuclear Information System (INIS)

    Wang, Hsueh-Sheng; Huang, Kuo-Yang; Huang, Yuh-Jeen; Su, Yu-Chuan; Tseng, Fan-Gang

    2015-01-01

    Highlights: • A low-operating temperature of the POM-mode micro methanol reformer is obtained. • The effect of channel design on the performance is studied. • The effect of solid content and binder’ ratio on the performance is studied. • The centrifugal process is benefit for the modification of performance. • 98% of methanol conversion rate of the micro reformer can be obtained at 180 °C. - Abstract: A partial oxidation methanol micro reformer (POM-μReformer) with finger-shaped channels for low operating temperature and high conversing efficiency is proposed in this study. The micro reformer employs POM reaction for low temperature operation (less than 200 °C), exothermic reaction, and quick start-up, as well as air feeding capability; and the finger type reaction chambers for increasing catalyst loading as well as reaction area for performance enhancement. In this study, centrifugal technique was introduced to assist on the catalyst loading with high amount and uniform distribution. The solid content (S), binder’s ratio (B), and channel design (the ratio between channel’s length and width, R) were investigated in detail to optimize the design parameters. Scanning electron microscopy (SEM), gas chromatography (GC), and inductively coupled plasma-mass spectrometer (ICP-MS) were employed to analyze the performance of the POM-μReformer. The result depicted that the catalyst content and reactive area could be much improved at the optimized condition, and the conversion rate and hydrogen selectivity approached 97.9% and 97.4%, respectively, at a very low operating temperature of 180 °C with scarce or no binder in catalyst. The POM-μReformer can supply hydrogen to fuel cells by generating 2.23 J/min for 80% H 2 utilization and 60% fuel cell efficiency at 2 ml/min of supplied reactant gas, including methanol, oxygen and argon at a mixing ratio of 12.2%, 6.1% and 81.7%, respectively

  20. Standard practice for evaluation of disbonding of bimetallic stainless alloy/steel plate for use in high-pressure, high-temperature refinery hydrogen service

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2001-01-01

    1.1 This practice covers a procedure for the evaluation of disbonding of bimetallic stainless alloy/steel plate for use in refinery high-pressure/high-temperature (HP/HT) gaseous hydrogen service. It includes procedures to (1) produce suitable laboratory test specimens, (2) obtain hydrogen charging conditions in the laboratory that are similar to those found in refinery HP/HT hydrogen gas service for evaluation of bimetallic specimens exposed to these environments, and (3) perform analysis of the test data. The purpose of this practice is to allow for comparison of data among test laboratories on the resistance of bimetallic stainless alloy/steels to hydrogen-induced disbonding (HID). 1.2 This practice applies primarily to bimetallic products fabricated by weld overlay of stainless alloy onto a steel substrate. Most of the information developed using this practice has been obtained for such materials. The procedures described herein, may also be appropriate for evaluation of hot roll bonded, explosive bonded...

  1. WC as a non-platinum hydrogen evolution electrocatalyst for high temperature PEM water electrolysers

    DEFF Research Database (Denmark)

    Nikiforov, Aleksey; Petrushina, Irina; Christensen, Erik

    2012-01-01

    Tungsten carbide (WC) nanopowder was tested as a non-platinum cathode electrocatalyst for polymer electrolyte membrane (PEM) water electrolysers, operating at elevated temperatures. It was prepared in thermal plasma reactor with confined plasma jet from WO3 precursor in combination with CH4...

  2. Numerical analysis of accidental hydrogen releases from high pressure storage at low temperatures

    DEFF Research Database (Denmark)

    Markert, Frank; Melideo, Daniele; Baraldi, Daniele

    2014-01-01

    . The vessel dynamics are modeled using a simplified engineering and a CFD model to evaluate the performance of various EOS to predict vessel pressures, temperatures mass flow rates and jet flame lengths. It is shown that the chosen EOS and the chosen specific heat capacity correlation are important to model...

  3. Symmetric and asymmetric zeolitic imidazolate frameworks (ZIFs)/polybenzimidazole (PBI) nanocomposite membranes for hydrogen purification at high temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Tingxu; Shi, Gui Min; Chung, Tai-Shung [Department of Chemical and Biomolecular Engineering, National University of Singapore, Singapore (Singapore)

    2012-11-15

    High-performance zeolitic imidazolate frameworks (ZIFs)/polybenzimidazole (PBI) nanocomposites are molecularly designed for hydrogen separation at high temperatures, and demonstrate it in a useful configuration as dual-layer hollow fibers for the first time. By incorporating as-synthesized nanoporous ZIF-8 nanoparticles into the high thermal stability but extremely low permeability polybenzimidazole (PBI), the resultant mixed matrix membranes show an impressive enhancement in H{sub 2} permeability as high as a hundred times without any significant deduction in H{sub 2}/CO{sub 2} selectivity. The 30/70 ZIF-8/PBI dense membrane has a H{sub 2} permeability of 105.4 Barrer and a H{sub 2}/CO{sub 2} selectivity of 12.3. This performance is far superior to ZIF-7/PBI membranes and is the best ever reported data for H{sub 2}-selective polymeric materials in the literature. Meanwhile, defect-free ZIF-8-PBI/Matrimid dual-layer hollow fibers are successfully fabricated, without post-annealing and coating, by optimizing ZIF-8 nanoparticle loadings, spinning conditions, and solvent-exchange procedures. Two types of hollow fibers targeted at either high H{sub 2}/CO{sub 2} selectivity or high H{sub 2} permeance are developed: i) PZM10-I B fibers with a medium H{sub 2} permeance of 64.5 GPU (2.16 x 10{sup -8} mol m{sup -2} s{sup -1} Pa{sup -1}) at 180 C and a high H{sub 2}/CO{sub 2} selectivity of 12.3, and, ii) PZM33-I B fibers with a high H{sub 2} permeance of 202 GPU (6.77 x 10{sup -8} mol m{sup -2} s{sup -1} Pa{sup -1}) at 180 C and a medium H{sub 2}/CO{sub 2} selectivity of 7.7. This work not only molecularly designs novel nanocomposite materials for harsh industrial applications, such as syngas and hydrogen production, but also, for the first time, synergistically combines the strengths of both ZIF-8 and PBI for energy-related applications. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  4. High temperature hydrogen sulfide adsorption on activated carbon - I. Effects of gas composition and metal addition

    Science.gov (United States)

    Cal, M.P.; Strickler, B.W.; Lizzio, A.A.

    2000-01-01

    Various types of activated carbon sorbents were evaluated for their ability to remove H2S from a simulated coal gas stream at a temperature of 550 ??C. The ability of activated carbon to remove H2S at elevated temperature was examined as a function of carbon surface chemistry (oxidation, thermal desorption, and metal addition), and gas composition. A sorbent prepared by steam activation, HNO3 oxidation and impregnated with Zn, and tested in a gas stream containing 0.5% H2S, 50% CO2 and 49.5% N2, had the greatest H2S adsorption capacity. Addition of H2, CO, and H2O to the inlet gas stream reduced H2S breakthrough time and H2S adsorption capacity. A Zn impregnated activated carbon, when tested using a simulated coal gas containing 0.5% H2S, 49.5% N2, 13% H2, 8.5% H2O, 21% CO, and 7.5% CO2, had a breakthrough time of 75 min, which was less than 25 percent of the length of breakthrough for screening experiments performed with a simplified gas mixture of 0.5% H2S, 50% CO2, and 49.5% N2.

  5. Hydrogen migration in Lu at low temperatures

    International Nuclear Information System (INIS)

    Yamakawa, K.

    1997-01-01

    The migration of hydrogen in Lu is determined by electrical resistance measurements in temperature range of 140-170 K. Disordered hydrogen atoms, which are formed by quenching, migrate to order during annealing in the above temperature range. The rate of the resistance decrease depends on the ordering rate of hydrogen. From the resistance decrease during isothermal annealings, the activation energy of hydrogen migration is determined as 0.43 eV (41.5 kJ mol -1 ). (orig.)

  6. Numerical analysis of performance of steam reformer of methane reforming hydrogen production system connected with high-temperature gas-cooled reactor

    International Nuclear Information System (INIS)

    Yin Huaqiang; Jiang Shengyao; Zhang Youjie

    2007-01-01

    Methane conversion rate and hydrogen output are important performance indexes of the steam reformer. The paper presents numerical analysis of performance of the reformer connected with high-temperature gas-cooled reactor HTR-10. Setting helium inlet flow rate fixed, performance of the reformer was examined with different helium inlet temperature, pressure, different process gas temperature, pressure, flow rate, and different steam to carbon ratio. As the range concerned, helium inlet temperature has remarkable influence on the performance, and helium inlet temperature, process gas temperature and pressure have little influence on the performance, and improving process gas flow rate, methane conversion rate decreases and hydrogen output increases, however improving steam to carbon ratio has reverse influence on the performance. (authors)

  7. Effect of high-temperature water and hydrogen on the fracture behavior of a low-alloy reactor pressure vessel steel

    International Nuclear Information System (INIS)

    Roychowdhury, S.; Seifert, H.-P.; Spätig, P.; Que, Z.

    2016-01-01

    Structural integrity of reactor pressure vessels (RPV) is critical for safety and lifetime. Possible degradation of fracture resistance of RPV steel due to exposure to coolant and hydrogen is a concern. In this study tensile and elastic-plastic fracture mechanics (EPFM) tests in air (hydrogen pre-charged) and EFPM tests in hydrogenated/oxygenated high-temperature water (HTW) was done, using a low-alloy RPV steel. 2–5 wppm hydrogen caused embrittlement in air tensile tests at room temperature (25 °C) and at 288 °C, effects being more significant at 25 °C and in simulated weld coarse grain heat affected zone material. Embrittlement at 288 °C is strain rate dependent and is due to localized plastic deformation. Hydrogen pre-charging/HTW exposure did not deteriorate the fracture resistance at 288 °C in base metal, for investigated loading rate range. Clear change in fracture morphology and deformation structures was observed, similar to that after air tests with hydrogen. - Highlights: • Hydrogen content, microstructure of LAS, and strain rate affects tensile properties at 288 °C. • Strength affects hydrogen embrittlement susceptibility to a greater extent than grain size. • Hydrogen in LAS leads to strain localization and restricts cross-slip at 288 °C. • Possible hydrogen pickup due to exposure to 288 °C water alters fracture surface appearance without affecting fracture toughness in bainitic base material. • Simulated weld heat affected zone microstructure shows unstable crack propagation in 288 °C water.

  8. Effect of high-temperature water and hydrogen on the fracture behavior of a low-alloy reactor pressure vessel steel

    Energy Technology Data Exchange (ETDEWEB)

    Roychowdhury, S., E-mail: sroy27@gmail.com [Paul Scherrer Institut, Nuclear Energy and Safety Research Department, Laboratory for Nuclear Materials, 5232 Villigen, PSI (Switzerland); Materials Processing & Corrosion Engineering Division, Mod-Lab, D-Block, Bhabha Atomic Research Centre, Mumbai 400085 (India); Seifert, H.-P.; Spätig, P.; Que, Z. [Paul Scherrer Institut, Nuclear Energy and Safety Research Department, Laboratory for Nuclear Materials, 5232 Villigen, PSI (Switzerland)

    2016-09-15

    Structural integrity of reactor pressure vessels (RPV) is critical for safety and lifetime. Possible degradation of fracture resistance of RPV steel due to exposure to coolant and hydrogen is a concern. In this study tensile and elastic-plastic fracture mechanics (EPFM) tests in air (hydrogen pre-charged) and EFPM tests in hydrogenated/oxygenated high-temperature water (HTW) was done, using a low-alloy RPV steel. 2–5 wppm hydrogen caused embrittlement in air tensile tests at room temperature (25 °C) and at 288 °C, effects being more significant at 25 °C and in simulated weld coarse grain heat affected zone material. Embrittlement at 288 °C is strain rate dependent and is due to localized plastic deformation. Hydrogen pre-charging/HTW exposure did not deteriorate the fracture resistance at 288 °C in base metal, for investigated loading rate range. Clear change in fracture morphology and deformation structures was observed, similar to that after air tests with hydrogen. - Highlights: • Hydrogen content, microstructure of LAS, and strain rate affects tensile properties at 288 °C. • Strength affects hydrogen embrittlement susceptibility to a greater extent than grain size. • Hydrogen in LAS leads to strain localization and restricts cross-slip at 288 °C. • Possible hydrogen pickup due to exposure to 288 °C water alters fracture surface appearance without affecting fracture toughness in bainitic base material. • Simulated weld heat affected zone microstructure shows unstable crack propagation in 288 °C water.

  9. An Analysis of Methanol and Hydrogen Production via High-Temperature Electrolysis Using the Sodium Cooled Advanced Fast Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Shannon M. Bragg-Sitton; Richard D. Boardman; Robert S. Cherry; Wesley R. Deason; Michael G. McKellar

    2014-03-01

    Integration of an advanced, sodium-cooled fast spectrum reactor into nuclear hybrid energy system (NHES) architectures is the focus of the present study. A techno-economic evaluation of several conceptual system designs was performed for the integration of a sodium-cooled Advanced Fast Reactor (AFR) with the electric grid in conjunction with wind-generated electricity. Cases in which excess thermal and electrical energy would be reapportioned within an integrated energy system to a chemical plant are presented. The process applications evaluated include hydrogen production via high temperature steam electrolysis and methanol production via steam methane reforming to produce carbon monoxide and hydrogen which feed a methanol synthesis reactor. Three power cycles were considered for integration with the AFR, including subcritical and supercritical Rankine cycles and a modified supercritical carbon dioxide modified Brayton cycle. The thermal efficiencies of all of the modeled power conversions units were greater than 40%. A thermal efficiency of 42% was adopted in economic studies because two of the cycles either performed at that level or could potentially do so (subcritical Rankine and S-CO2 Brayton). Each of the evaluated hybrid architectures would be technically feasible but would demonstrate a different internal rate of return (IRR) as a function of multiple parameters; all evaluated configurations showed a positive IRR. As expected, integration of an AFR with a chemical plant increases the IRR when “must-take” wind-generated electricity is added to the energy system. Additional dynamic system analyses are recommended to draw detailed conclusions on the feasibility and economic benefits associated with AFR-hybrid energy system operation.

  10. Hydrogen oxidation at high pressure and intermediate temperatures: experiments and kinetic modeling

    DEFF Research Database (Denmark)

    Hashemi, Hamid; Christensen, Jakob Munkholt; Gersen, Sander

    2015-01-01

    was varied from very oxidizing to strongly reducing conditions. The results supplement high-pressure data from RCM (900–1100 K) and shock tubes (900–2200 K). At the reducing conditions ( U = 12), oxidation started at 748–775 K while it was shifted to 798–823 K for stoichiometric and oxidizing conditions ( U...

  11. Emergence of a high-temperature superconductivity in hydrogen cycled Pd compounds as an evidence for super-stoichiometric H/D sites

    Energy Technology Data Exchange (ETDEWEB)

    Lipson, Andrei; Castano, Carlos; Miley, George [University of Illinois at Urbana - Champaign, lL (United States); Lipson, Andrei; Lyakhov, Boris [lnstitute of Physical Chemistry, RAS, Moscow (Russian Federation); Mitin, Alexander [P. Kapitza Institute for Physical Problems, RAS, Moscow (Russian Federation)

    2006-07-01

    Transport and magnetic properties of hydrogen cycled PdH{sub x} and Pd/PdO:H{sub x} (x {approx} = (4/6) x 10{sup -4}) nano-composite consisting of a Pd matrix with hydrogen trapped inside dislocation cores have been studied. The results suggest emergence of a high-temperature superconductivity stale of a condensed hydrogen phase confined inside deep dislocation cores in the Pd matrix. The possible role of hydrogen/deuterium filled dislocation nano-tubes is discussed. These dislocation cores could be considered as active centers of LENR triggering due to (i) short D-D separation distance ({approx}Bohr radius); (ii) high-local D-loading in the Pd and the corresponding effective lattice compression; (iii) a large optic phonon energy resulting in a most effective lattice-nuclei energy transfer.

  12. Emergence of a high-temperature superconductivity in hydrogen cycled Pd compounds as an evidence for super-stoichiometric H/D sites

    International Nuclear Information System (INIS)

    Lipson, Andrei; Castano, Carlos; Miley, George; Lipson, Andrei; Lyakhov, Boris; Mitin, Alexander

    2006-01-01

    Transport and magnetic properties of hydrogen cycled PdH x and Pd/PdO:H x (x ∼ = (4/6) x 10 -4 ) nano-composite consisting of a Pd matrix with hydrogen trapped inside dislocation cores have been studied. The results suggest emergence of a high-temperature superconductivity stale of a condensed hydrogen phase confined inside deep dislocation cores in the Pd matrix. The possible role of hydrogen/deuterium filled dislocation nano-tubes is discussed. These dislocation cores could be considered as active centers of LENR triggering due to (i) short D-D separation distance (∼Bohr radius); (ii) high-local D-loading in the Pd and the corresponding effective lattice compression; (iii) a large optic phonon energy resulting in a most effective lattice-nuclei energy transfer

  13. Emergence of a High-Temperature Superconductivity in Hydrogen Cycled pd Compounds as AN Evidence for Superstoihiometric H/d Sites

    Science.gov (United States)

    Lipson, Andrei; Castano, Carlos; Miley, George; Lipson, Andrei; Lyakhov, Boris; Mitin, Alexander

    2006-02-01

    Transport and magnetic properties of hydrogen cycled PdHx and Pd/PdO:Hx (x ~ (4/6) × 10-4) nano-composite consisting of a Pd matrix with hydrogen trapped inside dislocation cores have been studied. The results suggest emergence of a high-temperature superconductivity state of a condensed hydrogen phase confined inside deep dislocation cores in the Pd matrix. The possible role of hydrogen/deuterium filled dislocation nano-tubes is discussed. These dislocation cores could be considered as active centers of LENR triggering due to (i) short D-D separation distance (~Bohr radius); (ii) high-local D-loading in the Pd and the corresponding effective lattice compression; (iii) a large optic phonon energy resulting in a most effective lattice-nuclei energy transfer.

  14. The problems of using a high-temperature sodium coolant in nuclear power plants for the production of hydrogen and other innovative applications

    Science.gov (United States)

    Sorokin, A. P.; Alexeev, V. V.; Kuzina, Ju. A.; Konovalov, M. A.

    2017-11-01

    The intensity of the hydrogen sources arriving from the third contour of installation in second in comparison with the hydrogen sources on NPP BN-600 increases by two - three order at using of high-temperature nuclear power plants with the sodium coolant (HT-NPP) for drawing of hydrogen and other innovative applications (gasification and a liquefaction of coal, profound oil refining, transformation of biomass to liquid fuel, in the chemical industry, metallurgy, the food-processing industry etc.). For these conditions basic new technological solutions are offered. The main condition of their implementation is raise of hydrogen concentration in the sodium coolant on two - three order in comparison with the modern NPP, in a combination to hydrogen removal from sodium and its pumping out through membranes from vanadium or niobium. The researches with use diffusive model have shown possibility to expel a casium inflow in sodium through a leakproof shell of fuel rods if vary such parameters as a material of fuel rods shell, its thickness and maintenance time at design of fuel rods for high-temperature NPP. However maintenance of high-temperature NPP in the presence of casium in sodium is inevitable at loss of leakproof of a fuel rods shell. In these conditions for minimisation of casium diffusion in structural materials it is necessary to provide deep clearing of sodium from cesium.

  15. Low Temperature Hydrogen Antihydrogen Interactions

    International Nuclear Information System (INIS)

    Armour, E. A. G.; Chamberlain, C. W.

    2001-01-01

    In view of current interest in the trapping of antihydrogen (H-bar) atoms at low temperatures, we have carried out a full four-body variational calculation to determine s-wave elastic phase shifts for hydrogen antihydrogen scattering, using the Kohn Variational Principle. Terms outside the Born-Oppenheimer approximation have been taken into account using the formalism of Kolos and Wolniewicz. As far as we are aware, this is the first time that these terms have been included in an H H-bar scattering calculation. This is a continuation of earlier work on H-H-bar interactions. Preliminary results differ substantially from those calculated using the Born-Oppenheimer approximation. A method is outlined for reducing this discrepancy and taking the rearrangement channel into account.

  16. A rod-packing microporous hydrogen-bonded organic framework for highly selective separation of C2H2/CO2at room temperature

    KAUST Repository

    Li, Peng

    2014-11-13

    Self-assembly of a trigonal building subunit with diaminotriazines (DAT) functional groups leads to a unique rod-packing 3D microporous hydrogen-bonded organic framework (HOF-3). This material shows permanent porosity and demonstrates highly selective separation of C2H2/CO2 at ambient temperature and pressure.

  17. A rod-packing microporous hydrogen-bonded organic framework for highly selective separation of C2H2/CO2at room temperature

    KAUST Repository

    Li, Peng; He, Yabing; Zhao, Yunfeng; Weng, Linhong; Wang, Hailong; Krishna, Rajamani A A; Wu, Hui; Zhou, Wei; O'Keeffe, Michael A.; Han, Yu; Chen, Banglin

    2014-01-01

    Self-assembly of a trigonal building subunit with diaminotriazines (DAT) functional groups leads to a unique rod-packing 3D microporous hydrogen-bonded organic framework (HOF-3). This material shows permanent porosity and demonstrates highly selective separation of C2H2/CO2 at ambient temperature and pressure.

  18. Equilibrium studies on liquid ammonia-potassium amide-hydrogen system at high pressures and temperatures (Preprint No. CA-10)

    International Nuclear Information System (INIS)

    Donde, M.M.; Srinivasa, K.; Raman, S.

    1989-04-01

    Insoluble deposits were observed to form during the operation of Heavy Water Plant at Talcher, based on ammonia-hydrogen exchange process with potassium amide as catalyst. Experiments were undertaken to investigate this phenomenon under controlled conditions in the laboratory employing high pressures and elevated temperatures. It was observed that deposit formation was very minimal in the autoclave and no visible deposit was left on the strainer-filter, in all the experiments. Deposit analysis showed the presence of potassium hydroxide monohydrate as major component and alpha-potassium hydroxide and potassium azide as minor components. It is suggested that the presence of hydroxide may be due to the reaction of amide with the residual moisture in the system during the experiment and any ingress of moisture while opening for collection of deposit. Azide formation is explained by following reactions occurring during the experiments. NH 3 +KNH 2 →NH 2 -NH 2 +KH; NH 2 -NH 2 +KNH 2 →KN 3 +3H 2 . (author). 1 fig

  19. Experimental investigation of solid hydrogen pellet ablation in high-temperature plasmas using holographic interferometry and other diagnostics

    International Nuclear Information System (INIS)

    Thomas, C.E. Jr.

    1981-03-01

    The technology currently most favored for the refueling of fusion reactors is the high-velocity injection of solid hydrogen pellets. Design details are presented for a holographic interferometer/shadowgraph used to study the microscopic characteristics of a solid hydrogen pellet ablating in an approx. 1-keV plasma. Experimental data are presented for two sets of experiments in which the interferometer/shadowgraph was used to study approx. 1-mm-diam solid hydrogen pellets injected into the Impurity Study Experiment (ISX-B) tokamak at Oak Ridge National Laboratory (ORNL) at velocities of 1000 m/s. In addition to the use of the holographic interferometer, the pellet ablation process is diagnosed by studying the emission of Balmer-alpha photons and by using the available tokamak diagnostics

  20. Evaluation of the security of a hydrogen producing plant by means of the S I cycle coupled to a nuclear reactor of high temperature

    International Nuclear Information System (INIS)

    Ruiz S, T.; Francois, J. L.; Nelson, P. F.; Cruz G, M. J.

    2011-11-01

    At the present one of the processes that demonstrates, theoretically, to be one of the most efficient for the hydrogen production is the thermal-chemistry cycle Sulfur-Iodine. One way of obtaining the temperature ranges required by the process is through the helium coming from a very high temperature reactor. The coupling of the chemical plant with the nuclear plant presents aspects of security that should be analyzed; among them the analysis of the danger of the process materials is, with the purpose of implementing security measures to protect the facilities and equipment s, the environment and the population. These measures can be: emergency answer plans of the stations, definition of the minimum distance required among facilities, determination of the exclusion area, etc. In this study simulations were made with the computer code Phast in order to knowing the possible affectation areas due to the liberation of a great quantity of energy due to a helium leak to very high temperature, of toxic materials or by a possible hydrogen combustion. The results for the liberations of sulfuric acid, hydrogen, iodine, helium and sulfur dioxide are shown, specially. The operation conditions were taken of a combination of the preliminary design proposed by General Atomics and the optimized conditions by the Korea Advanced Institute of Science and Technology, considering a production of 1 kg-mol/s of hydrogen. The iodine was the material that presented a major affectation area. (Author)

  1. Process flow sheet evaluation of a nuclear hydrogen steelmaking plant applying very high temperature reactors for efficient steel production with less CO{sub 2} emissions

    Energy Technology Data Exchange (ETDEWEB)

    Kasahara, Seiji, E-mail: kasahara.seiji@jaea.go.jp; Inagaki, Yoshiyuki; Ogawa, Masuro

    2014-05-01

    Highlights: • CO{sub 2} emissions from a nuclear hydrogen steelmaking system was 13–21% of that from a blast furnace steelmaking system. • Heat input to shaft furnace in hydrogen steelmaking was large with much H{sub 2} consumption in the part. • Though hydrogen production thermal efficiency had influence on total heat input to hydrogen steelmaking, the effect on the CO{sub 2} emissions was small. • Steelmaking scale of a nuclear hydrogen steelamking plant with 2 VHTRs was a little smaller than that of the largest Midrex{sup ®} steelmaking plants. - Abstract: Recently, CO{sub 2} reduction is an important problem for steelmaking. Substitution of coal, presently used as a reducing agent of iron ore in blast furnaces, to hydrogen produced by non-fossil energy is a way to reduce CO{sub 2} emissions. In this study, the idea of nuclear hydrogen steelmaking (NHS) system was investigated using very high temperature reactor (VHTR) and thermochemical hydrogen production iodine–sulfur (IS) process. Heat input and CO{sub 2} emissions including material production, material transportation, and electricity generation were evaluation criteria. Results of the NHS system were compared with those of a conventional blast furnace steelmaking (BFS) system. Influence of heat input options to the steelmaking process and hydrogen production thermal efficiency of IS process were investigated for the NHS system. Though heat input to the NHS system was 130–142% of that to the BFS system, CO{sub 2} emissions of the system were 13–21%. Pre-heating of hydrogen by coal combustion before blowing to a shaft furnace was effective to decrease heat input, although CO{sub 2} emissions increased. Direct pre-heating by nuclear heat was also effective without increase of CO{sub 2} emissions if close location of the nuclear reactor to the steelmaking plant was publicly accepted. Hydrogen production thermal efficiency had a significant influence on the heat input. Conceptual design of a

  2. On-line hydrogen-isotope measurements of organic samples using elemental chromium: An extension for high temperature elemental-analyzer techniques

    Science.gov (United States)

    Gehre, Matthias; Renpenning, Julian; Gilevska, Tetyana; Qi, Haiping; Coplen, Tyler B.; Meijer, Harro A.J.; Brand, Willi A.; Schimmelmann, Arndt

    2015-01-01

    The high temperature conversion (HTC) technique using an elemental analyzer with a glassy carbon tube and filling (temperature conversion/elemental analysis, TC/EA) is a widely used method for hydrogen isotopic analysis of water and many solid and liquid organic samples with analysis by isotope-ratio mass spectrometry (IRMS). However, the TC/EA IRMS method may produce inaccurate δ2H results, with values deviating by more than 20 mUr (milliurey = 0.001 = 1‰) from the true value for some materials. We show that a single-oven, chromium-filled elemental analyzer coupled to an IRMS substantially improves the measurement quality and reliability for hydrogen isotopic compositions of organic substances (Cr-EA method). Hot chromium maximizes the yield of molecular hydrogen in a helium carrier gas by irreversibly and quantitatively scavenging all reactive elements except hydrogen. In contrast, under TC/EA conditions, heteroelements like nitrogen or chlorine (and other halogens) can form hydrogen cyanide (HCN) or hydrogen chloride (HCl) and this can cause isotopic fractionation. The Cr-EA technique thus expands the analytical possibilities for on-line hydrogen-isotope measurements of organic samples significantly. This method yielded reproducibility values (1-sigma) for δ2H measurements on water and caffeine samples of better than 1.0 and 0.5 mUr, respectively. To overcome handling problems with water as the principal calibration anchor for hydrogen isotopic measurements, we have employed an effective and simple strategy using reference waters or other liquids sealed in silver-tube segments. These crimped silver tubes can be employed in both the Cr-EA and TC/EA techniques. They simplify considerably the normalization of hydrogen-isotope measurement data to the VSMOW-SLAP (Vienna Standard Mean Ocean Water-Standard Light Antarctic Precipitation) scale, and their use improves accuracy of the data by eliminating evaporative loss and associated isotopic fractionation while

  3. On-line hydrogen-isotope measurements of organic samples using elemental chromium: an extension for high temperature elemental-analyzer techniques.

    Science.gov (United States)

    Gehre, Matthias; Renpenning, Julian; Gilevska, Tetyana; Qi, Haiping; Coplen, Tyler B; Meijer, Harro A J; Brand, Willi A; Schimmelmann, Arndt

    2015-01-01

    The high temperature conversion (HTC) technique using an elemental analyzer with a glassy carbon tube and filling (temperature conversion/elemental analysis, TC/EA) is a widely used method for hydrogen isotopic analysis of water and many solid and liquid organic samples with analysis by isotope-ratio mass spectrometry (IRMS). However, the TC/EA IRMS method may produce inaccurate δ(2)H results, with values deviating by more than 20 mUr (milliurey = 0.001 = 1‰) from the true value for some materials. We show that a single-oven, chromium-filled elemental analyzer coupled to an IRMS substantially improves the measurement quality and reliability for hydrogen isotopic compositions of organic substances (Cr-EA method). Hot chromium maximizes the yield of molecular hydrogen in a helium carrier gas by irreversibly and quantitatively scavenging all reactive elements except hydrogen. In contrast, under TC/EA conditions, heteroelements like nitrogen or chlorine (and other halogens) can form hydrogen cyanide (HCN) or hydrogen chloride (HCl) and this can cause isotopic fractionation. The Cr-EA technique thus expands the analytical possibilities for on-line hydrogen-isotope measurements of organic samples significantly. This method yielded reproducibility values (1-sigma) for δ(2)H measurements on water and caffeine samples of better than 1.0 and 0.5 mUr, respectively. To overcome handling problems with water as the principal calibration anchor for hydrogen isotopic measurements, we have employed an effective and simple strategy using reference waters or other liquids sealed in silver-tube segments. These crimped silver tubes can be employed in both the Cr-EA and TC/EA techniques. They simplify considerably the normalization of hydrogen-isotope measurement data to the VSMOW-SLAP (Vienna Standard Mean Ocean Water-Standard Light Antarctic Precipitation) scale, and their use improves accuracy of the data by eliminating evaporative loss and associated isotopic fractionation while

  4. Interaction between a high density-low temperature plasma and a frozen hydrogen pellet in a railgun injector

    International Nuclear Information System (INIS)

    Grapperhaus, M.J.

    1993-01-01

    A model has been developed which describes the ablation process of frozen hydrogen pellets in an electromagnetic railgun. The model incorporates the neutral gas shielding model in which the pellet surface is heated by incident electrons from the plasma arc. The heated surface then ablates, forming a neutral cloud which attenuates the incoming electrons. The energy lost in the cloud by the electrons heats the ablatant material as it flows into the plasma arc. Under steady-state conditions, a scaling law for the ablation rate was derived as a function of plasma-arc temperature and density. In addition, flow conditions and the criteria for the existence of a steady-state solution were formulated and subsequently examined under simplifying assumptions. Comparison with experimentally observed ablation rates shows good qualitative agreement

  5. Advanced CSiC composites for high-temperature nuclear heat transport with helium, molten salts, and sulphur-iodine thermochemical hydrogen process fluids

    International Nuclear Information System (INIS)

    Peterson, P.F.; Forsberg, Ch.W.; Pickard, P.S.

    2004-01-01

    This paper discusses the use of liquid-silicon-impregnated (LSI) carbon-carbon composites for the development of compact and inexpensive heat exchangers, piping, vessels and pumps capable of operating in the temperature range of 800 to 1 100 deg C with high-pressure helium, molten fluoride salts, and process fluids for sulfur-iodine thermochemical hydrogen production. LSI composites have several potentially attractive features, including ability to maintain nearly full mechanical strength to temperatures approaching 1 400 deg C, inexpensive and commercially available fabrication materials, and the capability for simple forming, machining and joining of carbon-carbon performs, which permits the fabrication of highly complex component geometries. In the near term, these materials may prove to be attractive for use with a molten-salt intermediate loop for the demonstration of hydrogen production with a gas-cooled high temperature reactor. In the longer term, these materials could be attractive for use with the molten-salt cooled advanced high temperature reactor, molten salt reactors, and fusion power plants. (author)

  6. Optimization of on-line hydrogen stable isotope ratio measurements of halogen- and sulfur-bearing organic compounds using elemental analyzer–chromium/high-temperature conversion isotope ratio mass spectrometry (EA-Cr/HTC-IRMS)

    Science.gov (United States)

    Gehre, Matthias; Renpenning, Julian; Geilmann, Heike; Qi, Haiping; Coplen, Tyler B.; Kümmel, Steffen; Ivdra, Natalija; Brand, Willi A.; Schimmelmann, Arndt

    2017-01-01

    Rationale: Accurate hydrogen isotopic analysis of halogen- and sulfur-bearing organics has not been possible with traditional high-temperature conversion (HTC) because the formation of hydrogen-bearing reaction products other than molecular hydrogen (H2) is responsible for non-quantitative H2 yields and possible hydrogen isotopic fractionation. Our previously introduced, new chromium-based EA-Cr/HTC-IRMS (Elemental Analyzer–Chromium/High-Temperature Conversion Isotope Ratio Mass Spectrometry) technique focused primarily on nitrogen-bearing compounds. Several technical and analytical issues concerning halogen- and sulfur-bearing samples, however, remained unresolved and required further refinement of the reactor systems.

  7. Research and development on is process components for hydrogen production. (2) Corrosion resistance of glass lining in high temperature sulfuric acid

    International Nuclear Information System (INIS)

    Tanaka, Nobuyuki; Iwatsuki, Jin; Kubo, Shinji; Terada, Atsuhiko; Onuki, Kaoru

    2009-01-01

    Japan Atomic Energy Agency has been conducting a research and development on hydrogen production system using High Temperature Gas-Cooled Reactor. As a part of this effort, thermochemical water-splitting cycle featuring iodine- and sulfur-compounds (IS process) is under development considering its potential of large-scale economical hydrogen production. The IS process constitutes very severe environments on the materials of construction because of the corrosive nature of process chemicals, especially of the high temperature acidic solution of sulfuric acid and hydriodic acid dissolving iodine. Therefore, selection of the corrosion-resistant materials and development of the components has been studied as a crucial subject of the process development. This paper discusses corrosion resistance of commercially available glass-lining material in high temperature sulfuric acid. Corrosion resistance of a soda glass used for glass-lining was examined by immersion tests. The experiments were performed in 47-90wt% sulfuric acids at temperatures of up to 400degC and for the maximum immersion time of 100 hours using an autoclave designed for the concerned tests. In every condition tested, no indication of localized corrosion such as defect formation or pitting corrosion was observed. Also, the corrosion rates decreased with the progress of immersion, and were low enough (≅0.1 mm/year) after 60-90 hours of immersion probably due to formation of a silica rich surface. (author)

  8. Nanodiamond for hydrogen storage: temperature-dependent hydrogenation and charge-induced dehydrogenation.

    Science.gov (United States)

    Lai, Lin; Barnard, Amanda S

    2012-02-21

    Carbon-based hydrogen storage materials are one of hottest research topics in materials science. Although the majority of studies focus on highly porous loosely bound systems, these systems have various limitations including use at elevated temperature. Here we propose, based on computer simulations, that diamond nanoparticles may provide a new promising high temperature candidate with a moderate storage capacity, but good potential for recyclability. The hydrogenation of nanodiamonds is found to be easily achieved, in agreement with experiments, though we find the stability of hydrogenation is dependent on the morphology of nanodiamonds and surrounding environment. Hydrogenation is thermodynamically favourable even at high temperature in pure hydrogen, ammonia, and methane gas reservoirs, whereas water vapour can help to reduce the energy barrier for desorption. The greatest challenge in using this material is the breaking of the strong covalent C-H bonds, and we have identified that the spontaneous release of atomic hydrogen may be achieved through charging of hydrogenated nanodiamonds. If the degree of induced charge is properly controlled, the integrity of the host nanodiamond is maintained, which indicates that an efficient and recyclable approach for hydrogen release may be possible. This journal is © The Royal Society of Chemistry 2012

  9. High temperature fast reactor for hydrogen production in Brazil; Reator nuclear rapido de altissima temperatura para producao de hidrogenio no Brasil

    Energy Technology Data Exchange (ETDEWEB)

    Nascimento, Jamil A. do; Ono, Shizuca; Guimaraes, Lamartine N.F. [Centro Tecnico Aeroespacial (CTA-IEAv), Sao Jose dos Campos, SP (Brazil). Inst. de Estudos Avancados]. E-mail: jamil@ieav.cta.br

    2008-07-01

    The main nuclear reactors technology for the Generation IV, on development phase for utilization after 2030, is the fast reactor type with high temperature output to improve the efficiency of the thermo-electric conversion process and to enable applications of the generated heat in industrial process. Currently, water electrolysis and thermo chemical cycles using very high temperature are studied for large scale and long-term hydrogen production, in the future. With the possible oil scarcity and price rise, and the global warming, this application can play an important role in the changes of the world energy matrix. In this context, it is proposed a fast reactor with very high output temperature, {approx} 1000 deg C. This reactor will have a closed fuel cycle; it will be cooled by lead and loaded with nitride fuel. This reactor may be used for hydrogen, heat and electricity production in Brazil. It is discussed a development strategy of the necessary technologies and some important problems are commented. The proposed concept presents characteristics that meet the requirements of the Generation IV reactor class. (author)

  10. Laser fluorescence spectroscopy by two-photon excitation for detection of hydrogen atoms in a periphery region of high temperature plasmas

    International Nuclear Information System (INIS)

    Kim, Hee-Je; Kajiwara, Toshinori; Motoyama, Sumio; Muraoka, Katsunori; Akazaki, Masanori; Okada, Tatsuo; Maeda, Mitsuo

    1989-01-01

    For measurements of atomic hydrogen density in the periphery region of high temperature plasmas, laser fluorescence spectroscopy (LFS) by two-photon excitation (1s-3s, 3d) was developed. Based upon the theoretical estimates for laser source requirements, which indicated the laser energy and spectral width to be more than 10 mJ (assuming the pulse duration of 10 ns) and several tens of picometers around the wavelength of 205.1 nm, respectively, the first Stokes generation in deuterium gas of ArF laser output was adopted and shown to have the necessary performance. Through the LFS experiment employing the laser source, the minimum detectable limit of atomic hydrogen, normalized by a laser power and an observing solid angle, was demonstrated to be 1 x 10 14 [m -3 · MW · sr], which is usually sufficient for the above purpose, and the accuracy of the density determination was shown to be within a factor 2. (author)

  11. Achievement report for fiscal 1974 on Sunshine Program. Research and development of hydrogen production technology using high-temperature and high-pressure water electrolysis; 1974 nendo koon koatsusui denkaiho ni yoru suiso seizo gijutsu no kenkyu kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1975-05-30

    The goals at present are to clarify conditions for the realization of the water electrolysis process relative to various primary energy sources and to experimentally construct a small practical electrobath to operate at high temperature and high pressure for the attainment of high economic efficiency. Efforts in this fiscal year are mentioned below. Surveys and studies are conducted about hydrogen production by water electrolysis and about achievements in the past and problems at present concerning hydrogen production by water electrolysis in Japan and overseas. The expected role of water electrolysis in various primary energy sources is also studied and evaluated. For a high-temperature high-pressure water electrolysis bath conceptual design (small test plant, bathing temperature 120 degrees C, pressure 20atm, hydrogen production rate 2Nm{sup 3}/h), studies are conducted about a constant-load type high-temperature high-pressure (bipolar) diaphragm-assisted water electrolysis bath and a variable-load type high-temperature high-pressure diaphragm-assisted water electrolysis bath. Surveys and studies are also conducted about the expected role of water electrolysis in various primary energy sources, and the role is evaluated. (NEDO)

  12. High capacity hydrogen storage nanocomposite materials

    Science.gov (United States)

    Zidan, Ragaiy; Wellons, Matthew S.

    2017-12-12

    A novel hydrogen absorption material is provided comprising a mixture of a lithium hydride with a fullerene. The subsequent reaction product provides for a hydrogen storage material which reversibly stores and releases hydrogen at temperatures of about 270.degree. C.

  13. Techno-economic study of hydrogen production by high temperature electrolysis coupled with an EPR-water steam production and coupling possibilities

    International Nuclear Information System (INIS)

    Tinoco, R. R.; Bouallou, C.; Mansilla, C.; Werkoff, F.

    2007-01-01

    Nuclear reactors present a wide range of coupling possibilities with several industrial processes, hydrogen production being one of them. Among the Pressurised Water nuclear Reactors (PWR), the new European Pressurised Reactor (EPR) offers the water steam production at low-medium temperatures, from 230 degree Celsius to 330 degree Celsius for the primary and secondary exchange circuits. The use of this water steam for hydrogen production by High Temperature Electrolysis is the subject of this study, under a French context. The study of this coupling, has considered two hypotheses. First, water steam drawing off in secondary circuit has been evaluated in terms of possible impact in electricity production and reactor availability. After the drawing off at 78 bar (EPR secondary circuit pressure), pressure has to be dropped in order to protect the high temperature electrolyser from damage, so an isenthalpic drop has been considered. Liquid-vapour equilibrium happens with pressure drops, so separation of gas phase and recycling of liquid phase are proposed. Second, only water steam production with an EPR has been evaluated. The feed water enters the secondary circuit and passes from liquid phase to vapour in the steam generators, and then all steam is canalized to the high temperature electrolyser. The potentiality of water steam production in the EPR has been evaluated from 15 to 40 bar. Small reactors could be the best choice if only water steam production is considered. After steam production, it steam enters into the High Temperature Electrolysis process, like a cold stream for two parallel series of three heat exchangers reaching temperatures up to 950 degree Celsius. Then the steam is heated by an electric device and finally it enters the electrolyser. The electrolysis product streams (hydrogen-steam mixture and oxygen) are used in the heat exchangers like hot streams. For both hypotheses, information about water composition has been studied in order to minimise

  14. Study on high temperature desulphurization (Part 2). Hydrogen sulphide adsorption and decomposition in the presence of manganese nodules

    Energy Technology Data Exchange (ETDEWEB)

    Yumura, Motoo; Furimsky, E. (National Chemical Lab. for Industry, Tsukuba, (Japan))

    1989-06-29

    Manganese nodule, with its large surface area and inclusion of much Fe and Mn, was found to have a high potentiality as an H{sub 2}S desulphurizing agent. Its desulphurization characteristics and reaction with H{sub 2}S were studied to confirm its potentiality as an H{sub 2}S desulphurizing agent. Improvement of its desulphurizing capacity by adding Ca was also attempted. The first stage of the desulphurization is sulphurizing by the agent. After the complete sulphurization, the adsorbent had catalytic effects on H{sub 2}S decomposition. The amount of H{sub 2}S desulphurization of the manganese nodule did not depend on temperature, but the amount of H{sub 2}S decomposition strongly depended on temperature, with the first and a half order respectively. The addition of 10 wt% of CaO to the manganese nodule improved the amount of desulphurization by 30%. The potentiality of the manganese nodule as a desulphurizing agent was verified, and it is suggested that low cost and high performance desulphurizing agents can be developed by adding low cost compounds which have affinity for H{sub 2}S and large surface areas. 11 refs., 4 figs., 2 tabs.

  15. Hydrogen Peroxide Cycling in High-Temperature Acidic Geothermal Springs and Potential Implications for Oxidative Stress Response

    Directory of Open Access Journals (Sweden)

    Margaux M. Meslé

    2017-05-01

    Full Text Available Hydrogen peroxide (H2O2, superoxide (O2•-, and hydroxyl radicals (OH• are produced in natural waters via ultraviolet (UV light-induced reactions between dissolved oxygen (O2 and organic carbon, and further reaction of H2O2 and Fe(II (i.e., Fenton chemistry. The temporal and spatial dynamics of H2O2 and other dissolved compounds [Fe(II, Fe(III, H2S, O2] were measured during a diel cycle (dark/light in surface waters of three acidic geothermal springs (Beowulf Spring, One Hundred Springs Plain, and Echinus Geyser Spring; pH = 3–3.5, T = 68–80°C in Norris Geyser Basin, Yellowstone National Park. In situ analyses showed that H2O2 concentrations were lowest (ca. 1 μM in geothermal source waters containing high dissolved sulfide (and where oxygen was below detection and increased by 2-fold (ca. 2–3 μM in oxygenated waters corresponding to Fe(III-oxide mat formation down the water channel. Small increases in dissolved oxygen and H2O2 were observed during peak photon flux, but not consistently across all springs sampled. Iron-oxide microbial mats were sampled for molecular analysis of ROS gene expression in two primary autotrophs of acidic Fe(III-oxide mat ecosystems: Metallosphaera yellowstonensis (Archaea and Hydrogenobaculum sp. (Bacteria. Expression (RT-qPCR assays of specific stress-response genes (e.g., superoxide dismutase, peroxidases of the primary autotrophs were used to evaluate possible changes in transcription across temporal, spatial, and/or seasonal samples. Data presented here documented the presence of H2O2 and general correlation with dissolved oxygen. Moreover, two dominant microbial populations expressed ROS response genes throughout the day, but showed less expression of key genes during peak sunlight. Oxidative stress response genes (especially external peroxidases were highly-expressed in microorganisms within Fe(III-oxide mat communities, suggesting a significant role for these proteins during survival and growth in

  16. Preliminary Conceptual Design and Development of Core Technology of Very High Temperature Gas-Cooled Reactor Hydrogen Production

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Jong Hwa; Kang, H. S.; Gil, C. S. and others

    2006-05-15

    For the nuclear hydrogen production system, the VHTR technology and the IS cycle technology are being developed. A comparative evaluation on the block type reactor and the pebble type reactor is performed to decide a proper nuclear hydrogen production reactor. 100MWt prismatic type reactor is tentatively decided and its safety characteristics are roughly investigated. Computation codes of nuclear design, thermo-fluid design, safety-performance analysis are developed and verified. Also, the development of a risk informed design technology is started. Experiments for metallic materials and graphites are carried out for the selection of materials of VHTR components. Diverse materials for process heat exchanger are studied in various corrosive environments. Pyrolytic carbon and SiC coating technology is developed and fuel manufacturing technology is basically established. Computer program is developed to evaluate the performance of coated particle fuels.

  17. Preliminary Conceptual Design and Development of Core Technology of Very High Temperature Gas-Cooled Reactor Hydrogen Production

    International Nuclear Information System (INIS)

    Chang, Jong Hwa; Kang, H. S.; Gil, C. S. and others

    2006-05-01

    For the nuclear hydrogen production system, the VHTR technology and the IS cycle technology are being developed. A comparative evaluation on the block type reactor and the pebble type reactor is performed to decide a proper nuclear hydrogen production reactor. 100MWt prismatic type reactor is tentatively decided and its safety characteristics are roughly investigated. Computation codes of nuclear design, thermo-fluid design, safety-performance analysis are developed and verified. Also, the development of a risk informed design technology is started. Experiments for metallic materials and graphites are carried out for the selection of materials of VHTR components. Diverse materials for process heat exchanger are studied in various corrosive environments. Pyrolytic carbon and SiC coating technology is developed and fuel manufacturing technology is basically established. Computer program is developed to evaluate the performance of coated particle fuels

  18. Selective hydrogen detection at high temperature by using yttria-stabilized zirconia-based sensor with coupled metal-oxide-based sensing electrodes

    International Nuclear Information System (INIS)

    Yamaguchi, Mami; Anggraini, Sri Ayu; Fujio, Yuki; Breedon, Michael; Plashnitsa, Vladimir V.; Miura, Norio

    2012-01-01

    A selective and sensitive hydrogen (H 2 ) sensor capable of working at a high operating temperature was developed by using a pair of metal-oxide-based SEs formed on a yttria-stabilized zirconia (YSZ) tube, operating as a mixed-potential type sensor. The utilization of SnO 2 (+30 wt.% YSZ) electrode together with NiO-TiO 2 electrode configured as a combined-type sensor, successfully diminished the response of the examined interfering gases (especially propene), while maintaining high response toward H 2 at an operating temperature of 600 °C under humid operating conditions. The developed sensor exhibited quick response to 100 ppm H 2 , as the 90% response time was observed to be 9 s. The sensing performance of the combined-type sensor was barely affected by changes in water vapor concentration within the range of 1–4 vol.%, suggesting the resilience of the sensor to function in realistic working conditions. This sensor exhibited a linear relationship between sensitivity and H 2 concentration on a logarithmic scale.

  19. Confinement of hydrogen at high pressure in carbon nanotubes

    Science.gov (United States)

    Lassila, David H [Aptos, CA; Bonner, Brian P [Livermore, CA

    2011-12-13

    A high pressure hydrogen confinement apparatus according to one embodiment includes carbon nanotubes capped at one or both ends thereof with a hydrogen-permeable membrane to enable the high pressure confinement of hydrogen and release of the hydrogen therethrough. A hydrogen confinement apparatus according to another embodiment includes an array of multi-walled carbon nanotubes each having first and second ends, the second ends being capped with palladium (Pd) to enable the high pressure confinement of hydrogen and release of the hydrogen therethrough as a function of palladium temperature, wherein the array of carbon nanotubes is capable of storing hydrogen gas at a pressure of at least 1 GPa for greater than 24 hours. Additional apparatuses and methods are also presented.

  20. In-situ, high pressure and temperature experimental determination of hydrogen isotope fractionation between coexisting hydrous melt and silicate-saturated aqueous fluid

    Science.gov (United States)

    Mysen, B. O.

    2012-12-01

    Hydrogen isotope fractionation between water-saturated silicate melt and silicate-saturated aqueous fluid has been determined experimentally, in-situ with the samples in the 450-800C and 101-1567 MPa temperature and pressure range, respectively. The temperatures are, therefore higher than those where hydrogen bonding in fluids and melts is important [1]. The experiments were conducted with a hydrothermal diamond anvil cell (HDAC) as the high-temperature/-pressure tool and vibrational spectroscopy to determine D/H fractionation. Compositions were along the haploandesite join, Na2Si4O9 - Na2(NaAl)4O9 [Al/(Al+Si)=0-0.1], and a 50:50 (by volume) H2O:D2O fluid mixture as starting material. Platinum metal was used to enhance equilibration rate. Isotopic equilibrium was ascertained by using variable experimental duration at given temperature and pressure. In the Al-free Na-silicate system, the enthalpy change of the (D/H) equilibrium of fluid is 3.1±0.7 kJ/mol, whereas for coexisting melt, ΔH=0 kJ/mol within error. With Al/(Al+Si)=0.1, ΔH=5.2±0.9 kJ/mol for fluid and near 0 within error for coexisting melt melt. For the exchange equilibrium between melt and fluid, H2O(melt)+D2O(fluid)=H2O(fluid)+D2O(melt), the ΔH=4.6±0.7 and 6.5±0.7 kJ/mol for the two Al-free and Al-bearing compositions, respectively, respectively. The D/H equilibration within fluids and melts and, therefore, D/H partitioning between coexisting fluid and melt reflect the influence of dissolved H2O(D2O) in melts and dissolved silicate components in H2O(D2O) fluid on their structure. The positive temperature- and pressure-dependence of silicate solubility and on silicate structure in silicate-saturated aqueous fluid governs the D/H fractionation in the fluid because increasing silicate solute concentration in fluid results in silicate polymerization [2]. These structural effects may be analogous to observed solute-dependent oxygen isotope fractionation between brine and CO2 [3]. In the temperature

  1. High-temperature electrochemical performance of low-cost La–Ni–Fe based hydrogen storage alloys with different preparation methods

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Qiannan [Department of Advanced Energy Materials, College of Materials Science and Engineering, Sichuan University, Chengdu 610065 (China); Zhu, Ding [Institute of New Energy and Low-Carbon Technology, Sichuan University, Chengdu 610065 (China); Zhou, Wanhai; Zhong, Chenglin; Wu, Chaoling [Department of Advanced Energy Materials, College of Materials Science and Engineering, Sichuan University, Chengdu 610065 (China); Chen, Yungui, E-mail: ygchen60@aliyun.com [Department of Advanced Energy Materials, College of Materials Science and Engineering, Sichuan University, Chengdu 610065 (China); Institute of New Energy and Low-Carbon Technology, Sichuan University, Chengdu 610065 (China)

    2016-04-15

    Highlights: • Effects of four different preparation processes were studied at 20/60 °C. • All NS + HT, RS and RS + HT processes can optimize the thermodynamic performance. • The HT process can provoke the precipitation of A{sub 2}B{sub 7} and leads to a poor cycling life. • Al exhibits the most remarkable dissolution for all the alloys, especially at 60 °C. - Abstract: In order to optimize the microstructure and high temperature electrochemical performances of low-cost AB{sub 5}-type Ml(NiMnAl){sub 4.2}Co{sub 0.3}Fe{sub 0.5} hydrogen storage electrode alloys, four different preparation methods including normal solidification (NS), normal solidification and 900 °C heat treatment (NS + HT), rapid solidification (RS), rapid solidification and 900 °C heat treatment (RS + HT) were adopted in this work. All alloys exhibit CaCu{sub 5} type hexagonal structure and there is a small amount of A{sub 2}B{sub 7} phase in NS + HT and RS + HT alloys. It is found the using of HT process can decrease the hydrogen equilibrium plateau pressure, the plateau slope and hysteresis at 40, 60 and 80 °C. The NS + HT and RS + HT alloys also possess better activation, high rate discharge performance, larger discharge capacity, but poor cycling performance due to the existence of A{sub 2}B{sub 7} phase which can accelerate dissolution of Ni, Mn and Fe elements in KOH alkaline electrolyte. The RS process can make alloy exhibit the best cycling performance especially at 60 °C.

  2. High temperature materials

    International Nuclear Information System (INIS)

    2003-01-01

    The aim of this workshop is to share the needs of high temperature and nuclear fuel materials for future nuclear systems, to take stock of the status of researches in this domain and to propose some cooperation works between the different research organisations. The future nuclear systems are the very high temperature (850 to 1200 deg. C) gas cooled reactors (GCR) and the molten salt reactors (MSR). These systems include not only the reactor but also the fabrication and reprocessing of the spent fuel. This document brings together the transparencies of 13 communications among the 25 given at the workshop: 1) characteristics and needs of future systems: specifications, materials and fuel needs for fast spectrum GCR and very high temperature GCR; 2) high temperature materials out of neutron flux: thermal barriers: materials, resistance, lifetimes; nickel-base metal alloys: status of knowledge, mechanical behaviour, possible applications; corrosion linked with the gas coolant: knowledge and problems to be solved; super-alloys for turbines: alloys for blades and discs; corrosion linked with MSR: knowledge and problems to be solved; 3) materials for reactor core structure: nuclear graphite and carbon; fuel assembly structure materials of the GCR with fast neutron spectrum: status of knowledge and ceramics and cermets needs; silicon carbide as fuel confinement material, study of irradiation induced defects; migration of fission products, I and Cs in SiC; 4) materials for hydrogen production: status of the knowledge and needs for the thermochemical cycle; 5) technologies: GCR components and the associated material needs: compact exchangers, pumps, turbines; MSR components: valves, exchangers, pumps. (J.S.)

  3. Low temperature heat capacity of lutetium and lutetium hydrogen alloys

    International Nuclear Information System (INIS)

    Thome, D.K.

    1977-10-01

    The heat capacity of high purity electrotransport refined lutetium was measured between 1 and 20 0 K. Results for theta/sub D/ were in excellent agreement with theta values determined from elastic constant measurements. The heat capacity of a series of lutetium-hydrogen solid solution alloys was determined and results showed an increase in γ from 8.2 to about 11.3 mJ/g-atom-K 2 for hydrogen content increasing from zero to about one atomic percent. Above one percent hydrogen γ decreased with increasing hydrogen contents. The C/T data showed an increase with temperature decreasing below about 2.5 0 K for samples with 0.1 to 1.5 atomic percent hydrogen. This accounts for a large amount of scatter in theta/sub D/ versus hydrogen content in this range. The heat capacity of a bulk sample of lutetium dihydride was measured between 1 and 20 0 K and showed a large increase in theta/sub D/ and a large decrease in γ compared to pure lutetium

  4. The equilibrium hydrogen pressure-temperature diagram for the liquid sodium-hydrogen-oxygen system

    International Nuclear Information System (INIS)

    Knights, C.F.; Whittingham, A.C.

    1982-01-01

    The underlying equilibria in the sodium-hydrogen-oxygen system are presented in the form of a completmentary hydrogen equilibrium pressure-temperature diagram, constructed by using published data and supplemented by experimental measurements of hydrogen equilibrium pressures over condensed phases in the system. Possible applications of the equilibrium pressure-temperature phase diagram limitations regarding its use are outlined

  5. Facile fabrication of high-performance InGaZnO thin film transistor using hydrogen ion irradiation at room temperature

    Energy Technology Data Exchange (ETDEWEB)

    Ahn, Byung Du [School of Electrical and Electronic Engineering, 50, Yonsei University, Seoul 120-749 (Korea, Republic of); Park, Jin-Seong [Division of Materials Science and Engineering, Hanyang University, Seoul 133-791 (Korea, Republic of); Chung, K. B., E-mail: kbchung@dongguk.edu [Division of Physics and Semiconductor Science, Dongguk University, Seoul 100-715 (Korea, Republic of)

    2014-10-20

    Device performance of InGaZnO (IGZO) thin film transistors (TFTs) are investigated as a function of hydrogen ion irradiation dose at room temperature. Field effect mobility is enhanced, and subthreshold gate swing is improved with the increase of hydrogen ion irradiation dose, and there is no thermal annealing. The electrical device performance is correlated with the electronic structure of IGZO films, such as chemical bonding states, features of the conduction band, and band edge states below the conduction band. The decrease of oxygen deficient bonding and the changes in electronic structure of the conduction band leads to the improvement of device performance in IGZO TFT with an increase of the hydrogen ion irradiation dose.

  6. Low temperature catalytic reforming of heptane to hydrogen and syngas

    Directory of Open Access Journals (Sweden)

    M.E.E. Abashar

    2016-09-01

    Full Text Available The production of hydrogen and syngas from heptane at a low temperature is studied in a circulating fast fluidized bed membrane reactor (CFFBMR. A thin film of palladium-based membrane is employed to the displacement of the thermodynamic equilibrium for high conversion and yield. A mathematical model is developed to simulate the reformer. A substantial improvement of the CFFBMR is achieved by implementing the thin hydrogen membrane. The results showed that almost complete conversion of heptane and 46.25% increase of exit hydrogen yield over the value without membrane are achieved. Also a wide range of the H2/CO ratio within the recommended industrial range is obtained. The phenomena of high spikes of maximum nature at the beginning of the CFFBMR are observed and explanation offered. The sensitivity analysis results have shown that the increase of the steam to carbon feed ratio can increase the exit hydrogen yield up to 108.29%. It was found that the increase of reaction side pressure at a high steam to carbon feed ratio can increase further the exit hydrogen yield by 49.36% at a shorter reactor length. Moreover, the increase of reaction side pressure has an important impact in a significant decrease of the carbon dioxide and this is a positive sign for clean environment.

  7. A high performance hydrogen sulfide gas sensor based on porous α-Fe{sub 2}O{sub 3} operates at room-temperature

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Yanwu; Chen, Weimei; Zhang, Shouchao; Kuang, Zhong; Ao, Dongyi [School of Physical Electronics, University of Electronic Science and Technology of China, Chengdu, 610054 (China); Alkurd, Nooraldeen Rafat; Zhou, Weilie [Advanced Materials Research Institute, University of New Orleans, New Orleans, LA 70148 (United States); Liu, Wei [School of Physical Electronics, University of Electronic Science and Technology of China, Chengdu, 610054 (China); Shen, Wenzhong [Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan, 030001 (China); Li, Zhijie, E-mail: zhijieli@uestc.edu.cn [School of Physical Electronics, University of Electronic Science and Technology of China, Chengdu, 610054 (China)

    2015-10-01

    Highlights: • Novel porous α-Fe{sub 2}O{sub 3} nanoparticles were prepared by a facile hydrothermal method. • The sensor based on porous α-Fe{sub 2}O{sub 3} exhibits high sensitivity towards H{sub 2}S gas. • The detection limit towards H{sub 2}S gas was as low as 50 ppb at room temperature. • The sensor exhibits excellent selectivity against other toxic and noxious gases. - Abstract: Porous α-Fe{sub 2}O{sub 3} nanoparticles were synthesized by simple annealing of β-FeOOH precursor derived from a facile hydrothermal route, the structures and morphologies of the as-prepared product were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The results showed that the average crystallite size of the obtained porous α-Fe{sub 2}O{sub 3} was 34 nm and exits numerous irregularly distributed pores with a diameter varying from 2 nm to 10 nm on the particle surface. The gas-sensing properties of the sensor based on porous α-Fe{sub 2}O{sub 3} nanoparticles were investigated, and the result showed that the sensor exhibited a high performance in hydrogen sulfide (H{sub 2}S) detection at room temperature. The highest sensitivity reached 38.4 for 100 ppm H{sub 2}S, and the detection limit was as low as 50 ppb. In addition, the response of the sensor towards other gases including C{sub 2}H{sub 5}OH, CO, H{sub 2} and NH{sub 3} indicates the sensor has an excellent selectivity to detection H{sub 2}S gas. Finally, the sensing mechanism of the sensor towards H{sub 2}S was also discussed.

  8. Low-cost fabrication of highly sensitive room temperature hydrogen sensor based on ordered mesoporous Co-doped TiO2 structure

    Science.gov (United States)

    Li, Zhong; Haidry, Azhar Ali; Wang, Tao; Yao, Zheng Jun

    2017-07-01

    The development of cost-effective gas sensors with improved sensing properties and minimum power consumption for room temperature hydrogen leakage monitoring is in increasing demand. In this context, this report focus on the facile fabrication of ordered mesoporous TiO2 via evaporation-induced self-assembly route. With the controlled doping threshold (3%Co-TiO2), the output resistance change to 1000 ppm H2 is ˜4.1 × 103 with the response time of 66 s. The sensor response exhibits power law dependence with an increase in the hydrogen concentration, where the power law coefficient was found not only specific to the kind of target gas but also related to temperature. Further, the effect of structure integrity with doping level and humidity on sensing characteristics is interpreted in terms of variation in surface potential eVS and depletion region w caused by the adsorption of molecular oxygen O2-.

  9. Evaluation of two processes of hydrogen production starting from energy generated by high temperature nuclear reactors; Evaluacion de dos procesos de produccion de hidrogeno a partir de energia generada por reactores nucleares de alta temperatura

    Energy Technology Data Exchange (ETDEWEB)

    Valle H, J., E-mail: jvalle@upmh.edu.mx [Universidad Politecnica Metropolitana de Hidalgo, Boulevard Acceso a Tolcayuca 1009, Ex-Hacienda San Javier, 43860 Tolcayuca, Hidalgo (Mexico)

    2013-10-15

    In this work an evaluation to two processes of hydrogen production using energy generated starting from high temperature nuclear reactors (HTGR's) was realized. The evaluated processes are the electrolysis of high temperature and the thermo-chemistry cycle Iodine-Sulfur. The electrolysis of high temperature, contrary to the conventional electrolysis, allows reaching efficiencies of up to 60% because when increasing the temperature of the water, giving thermal energy, diminishes the electric power demand required to separate the molecule of the water. However, to obtain these efficiencies is necessary to have water vapor overheated to more than 850 grades C, temperatures that can be reached by the HTGR. On the other hand the thermo-chemistry cycle Iodine-Sulfur, developed by General Atomics in the 1970 decade, requires two thermal levels basically, the great of them to 850 grades C for decomposition of H{sub 2}SO{sub 4} and another minor to 360 grades C approximately for decomposition of H I, a high temperature nuclear reactor can give the thermal energy required for the process whose products would be only hydrogen and oxygen. In this work these two processes are described, complete models are developed and analyzed thermodynamically that allow to couple each hydrogen generation process to a reactor HTGR that will be implemented later on for their dynamic simulation. The obtained results are presented in form of comparative data table of each process, and with them the obtained net efficiencies. (author)

  10. Dependence of hydrogen-induced lattice defects and hydrogen embrittlement of cold-drawn pearlitic steels on hydrogen trap state, temperature, strain rate and hydrogen content

    International Nuclear Information System (INIS)

    Doshida, Tomoki; Takai, Kenichi

    2014-01-01

    The effects of the hydrogen state, temperature, strain rate and hydrogen content on hydrogen embrittlement susceptibility and hydrogen-induced lattice defects were evaluated for cold-drawn pearlitic steel that absorbed hydrogen in two trapping states. Firstly, tensile tests were carried out under various conditions to evaluate hydrogen embrittlement susceptibility. The results showed that peak 2 hydrogen, desorbed at temperatures above 200 °C as determined by thermal desorption analysis (TDA), had no significant effect on hydrogen embrittlement susceptibility. In contrast, hydrogen embrittlement susceptibility increased in the presence of peak 1 hydrogen, desorbed from room temperature to 200 °C as determined by TDA, at temperatures higher than −30 °C, at lower strain rates and with higher hydrogen content. Next, the same effects on hydrogen-induced lattice defects were also evaluated by TDA using hydrogen as a probe. Peak 2 hydrogen showed no significant effect on either hydrogen-induced lattice defects or hydrogen embrittlement susceptibility. It was found that hydrogen-induced lattice defects formed under the conditions where hydrogen embrittlement susceptibility increased. This relationship indicates that hydrogen embrittlement susceptibility was higher under the conditions where the formation of hydrogen-induced lattice defects tended to be enhanced. Since hydrogen-induced lattice defects formed by the interaction between hydrogen and strain were annihilated by annealing at a temperature of 200 °C, they were presumably vacancies or vacancy clusters. One of the common atomic-level changes that occur in cold-drawn pearlitic steel showing higher hydrogen embrittlement susceptibility is the formation of vacancies and vacancy clusters

  11. High hydrogen desorption properties of Mg-based nanocomposite at moderate temperatures: The effects of multiple catalysts in situ formed by adding nickel sulfides/graphene

    Science.gov (United States)

    Xie, Xiubo; Chen, Ming; Liu, Peng; Shang, Jiaxiang; Liu, Tong

    2017-12-01

    Nickel sulfides decorated reduced graphene oxide (rGO) has been produced by co-reducing Ni2+ and graphene oxide (GO), and is subsequently ball milled with Mg nanoparticles (NPs) produced by hydrogen plasma metal reaction (HPMR). The nickel sulfides of about 800 nm completely in situ change to MgS, Mg2Ni and Ni multiple catalysts after first hydrogenation/dehydrogenation process at 673 K. The Mg-5wt%NiS/rGO nanocomposite shows the highest hydrogen desorption kinetics and capacity properties, and the catalytic effect order of the additives is NiS/rGO, NiS and rGO. At 573 K, the Mg-NiS/rGO nanocomposite can quickly desorb 3.7 wt% H2 in 10 min and 4.5 wt% H2 in 60 min. The apparent hydrogen absorption and desorption activation energies of the Mg-5wt%NiS/rGO nanocomposite are decreased to 44.47 and 63.02 kJ mol-1, smaller than those of the Mg-5wt%rGO and Mg-5wt%NiS samples. The best hydrogen desorption properties of the Mg-5wt%NiS/rGO nanocomposite can be explained by the synergistic catalytic effects of the highly dispersed MgS, Mg2Ni and Ni catalysts on the rGO sheets, and the more nucleation sites between the catalysts, rGO sheets and Mg matrix.

  12. Low temperature, low pressure hydrogen gettering

    International Nuclear Information System (INIS)

    Anderson, D.R.; Courtney, R.L.; Harrah, L.A.

    1975-01-01

    A system is described for the gettering of hydrogen and its isotopes. The gettering materials are painted or coated onto, or otherwise disposed in an area or volume from which hydrogen is to be removed

  13. On the room-temperature phase diagram of high pressure hydrogen: An ab initio molecular dynamics perspective and a diffusion Monte Carlo study

    International Nuclear Information System (INIS)

    Chen, Ji; Ren, Xinguo; Li, Xin-Zheng; Alfè, Dario; Wang, Enge

    2014-01-01

    The finite-temperature phase diagram of hydrogen in the region of phase IV and its neighborhood was studied using the ab initio molecular dynamics (MD) and the ab initio path-integral molecular dynamics (PIMD). The electronic structures were analyzed using the density-functional theory (DFT), the random-phase approximation, and the diffusion Monte Carlo (DMC) methods. Taking the state-of-the-art DMC results as benchmark, comparisons of the energy differences between structures generated from the MD and PIMD simulations, with molecular and dissociated hydrogens, respectively, in the weak molecular layers of phase IV, indicate that standard functionals in DFT tend to underestimate the dissociation barrier of the weak molecular layers in this mixed phase. Because of this underestimation, inclusion of the quantum nuclear effects (QNEs) in PIMD using electronic structures generated with these functionals leads to artificially dissociated hydrogen layers in phase IV and an error compensation between the neglect of QNEs and the deficiencies of these functionals in standard ab initio MD simulations exists. This analysis partly rationalizes why earlier ab initio MD simulations complement so well the experimental observations. The temperature and pressure dependencies for the stability of phase IV were also studied in the end and compared with earlier results

  14. Grain boundary selective oxidation and intergranular stress corrosion crack growth of high-purity nickel binary alloys in high-temperature hydrogenated water

    Energy Technology Data Exchange (ETDEWEB)

    Bruemmer, S. M.; Olszta, M. J.; Toloczko, M. B.; Schreiber, D. K.

    2018-02-01

    The effects of alloying elements in Ni-5at%X binary alloys on intergranular (IG) corrosion and stress corrosion cracking (SCC) have been assessed in 300-360°C hydrogenated water at the Ni/NiO stability line. Alloys with Cr or Al additions exhibited grain boundary oxidation and IGSCC, while localized degradation was not observed for pure Ni, Ni-Cu or Ni-Fe alloys. Environment-enhanced crack growth was determined by comparing the response in water and N2 gas. Results demonstrate that selective grain boundary oxidation of Cr and Al promoted IGSCC of these Ni alloys in hydrogenated water.

  15. Synthesis of hydrogen-carbon clathrate material and hydrogen evolution therefrom at moderate temperatures and pressures

    Science.gov (United States)

    Lueking, Angela [State College, PA; Narayanan, Deepa [Redmond, WA

    2011-03-08

    A process for making a hydrogenated carbon material is provided which includes forming a mixture of a carbon source, particularly a carbonaceous material, and a hydrogen source. The mixture is reacted under reaction conditions such that hydrogen is generated and/or released from the hydrogen source, an amorphous diamond-like carbon is formed, and at least a portion of the generated and/or released hydrogen associates with the amorphous diamond-like carbon, thereby forming a hydrogenated carbon material. A hydrogenated carbon material including a hydrogen carbon clathrate is characterized by evolution of molecular hydrogen at room temperature at atmospheric pressure in particular embodiments of methods and compositions according to the present invention.

  16. Supersymmetry at high temperatures

    International Nuclear Information System (INIS)

    Das, A.; Kaku, M.

    1978-01-01

    We investigate the properties of Green's functions in a spontaneously broken supersymmetric model at high temperatures. We show that, even at high temperatures, we do not get restoration of supersymmetry, at least in the one-loop approximation

  17. Low temperature ultrasonic study of hydrogen in niobium

    International Nuclear Information System (INIS)

    Poker, D.B.

    1979-01-01

    Measurements were made of the velocity and attenuation of ultrasonic waves in niobium containing 1000 ppM oxygen with additional concentrations of hydrogen, to determine the properties of a relaxation of the hydrogen which appears below 10 K. Measurements were made as a function of temperature, frequency, polarization of the ultrasonic wave, hydrogen isotope, and concentration of hydrogen and oxygen. The Birnbaum--Flynn model of hydrogen tunnelling is modified to take into account the trapping of hydrogen by interstitial impurities. An Orbach process is proposed for a relaxation between the degenerate first excited states. Three parameters which are determined by the hydrogen ultrasonic attenuation data are sufficient to describe the properties of this model. The model correctly predicts the presence of unusual features of the relaxation which are not contained in a classical model of hydrogen motion over a potential barrrier; the decrease of the hydrogen relaxation strength at low temperatures, the decrease in velocity below the relaxation temperature without a corresponding effect in the attenuation, and the broadness of the deuterium decrement peak compared to that for hydrogen. A reasonable fit to the velocity data for low concentration of hydrogen is made by the model with no adjustable parameters. A fit to the heat capacity can be made with the addition of parameters representing the strain effects of the oxygen trapping

  18. Atomic hydrogen effects on high-Tc superconductors

    International Nuclear Information System (INIS)

    Frantskevich, N.V.; Ulyashin, A.G.; Alifanov, A.V.; Stepanenko, A.V.; Fedotova, V.V.

    1999-01-01

    The atomic hydrogen effects on the properties of bulk high-temperature superconductors were investigated. It is shown that the insertion of the atomic hydrogen into the bulk of these materials from a DC plasma leads to the increase of the critical current density J c for YBaCuO(123) as well as for BiSrCaCuO(2223) high-temperature superconductors. It is found that the hydrogenation of the He implanted samples with following annealing leads to the optically detected blistering on the surface. It means that the textured thin subsurface layers of high-temperature superconductors can be formed by this method. The improvement of superconductivity by atomic hydrogen can be explained by the passivation of dangling bonds and defects on grain boundaries of these materials

  19. Improvement in low-temperature and instantaneous high-rate output performance of Al-free AB5-type hydrogen storage alloy for negative electrode in Ni/MH battery: Effect of thermodynamic and kinetic regulation via partial Mn substituting

    Science.gov (United States)

    Zhou, Wanhai; Zhu, Ding; Tang, Zhengyao; Wu, Chaoling; Huang, Liwu; Ma, Zhewen; Chen, Yungui

    2017-03-01

    A series of Al-free Mn-modified AB5-type hydrogen storage alloys have been designed and the effects of thermodynamic stability and electrochemical kinetics on electrochemical performance via Mn substituting have been investigated. Compared with high-Al alloys, the Al-free alloys in this study have better low-temperature performance and instantaneous high-rate output because of the higher surface catalytic ability. After partial substitution of Ni by Mn, both the hydrogen desorption capacity and plateau pressure decrease, and correspondingly results in an improved thermodynamic stability which is adverse to low-temperature delivery. Additionally, with the improvement of charge acceptance ability and anti-corrosion property via Mn substitution, the room-temperature discharge capacity and cycling stability increase slightly. However, Mn adversely affects the electrochemical kinetics and deteriorates both the surface catalytic ability and the bulk hydrogen diffusion ability, leading to the drop of low-temperature dischargeability, high-rate dischargeability and peak power (Ppeak). Based on the thermodynamic and kinetic regulation and overall electrochemical properties, the optimal composition is obtained when x = 0.2, the discharge capacity is 243.6 mAh g-1 at -40 °C with 60 mA g-1, and the Ppeak attains to 969.6 W kg-1 at -40 °C.

  20. Experimental evaluation of improved dual temperature hydrogen isotopic exchange reaction system

    International Nuclear Information System (INIS)

    Asakura, Yamato; Uchida, Shunsuke

    1984-01-01

    A proposed dual temperature hydrogen isotopic exchange reaction system between water and hydrogen gas is evaluated experimentally. The proposed system is composed of low temperature co-current reactors for reaction between water mists and hydrogen gas and high temperature co-current reactors for reaction between water vapor and hydrogen gas. Thus, operation is possible under atmospheric pressure with high reaction efficiency. Using the pilot test system which is composed of ten low temperature (30 0 C) reaction units and ten high temperature (200 0 C) reaction units, an experimental separation of deuterium from light water is carried out. The enrichment factor under steady state conditions, its dependency on operating time, and the reaction period necessary to obtain the steady state enrichment factor are determined experimentally and compared with calculations. It is shown that separation ability in a multistage reaction system can be estimated by numerical calculation using actual reaction efficiency in a unit reactor. (author)

  1. High temperature materials; Materiaux a hautes temperatures

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2003-07-01

    The aim of this workshop is to share the needs of high temperature and nuclear fuel materials for future nuclear systems, to take stock of the status of researches in this domain and to propose some cooperation works between the different research organisations. The future nuclear systems are the very high temperature (850 to 1200 deg. C) gas cooled reactors (GCR) and the molten salt reactors (MSR). These systems include not only the reactor but also the fabrication and reprocessing of the spent fuel. This document brings together the transparencies of 13 communications among the 25 given at the workshop: 1) characteristics and needs of future systems: specifications, materials and fuel needs for fast spectrum GCR and very high temperature GCR; 2) high temperature materials out of neutron flux: thermal barriers: materials, resistance, lifetimes; nickel-base metal alloys: status of knowledge, mechanical behaviour, possible applications; corrosion linked with the gas coolant: knowledge and problems to be solved; super-alloys for turbines: alloys for blades and discs; corrosion linked with MSR: knowledge and problems to be solved; 3) materials for reactor core structure: nuclear graphite and carbon; fuel assembly structure materials of the GCR with fast neutron spectrum: status of knowledge and ceramics and cermets needs; silicon carbide as fuel confinement material, study of irradiation induced defects; migration of fission products, I and Cs in SiC; 4) materials for hydrogen production: status of the knowledge and needs for the thermochemical cycle; 5) technologies: GCR components and the associated material needs: compact exchangers, pumps, turbines; MSR components: valves, exchangers, pumps. (J.S.)

  2. An effective temperature compensation approach for ultrasonic hydrogen sensors

    Science.gov (United States)

    Tan, Xiaolong; Li, Min; Arsad, Norhana; Wen, Xiaoyan; Lu, Haifei

    2018-03-01

    Hydrogen is a kind of promising clean energy resource with a wide application prospect, which will, however, cause a serious security issue upon the leakage of hydrogen gas. The measurement of its concentration is of great significance. In a traditional approach of ultrasonic hydrogen sensing, a temperature drift of 0.1 °C results in a concentration error of about 250 ppm, which is intolerable for trace amount of gas sensing. In order to eliminate the influence brought by temperature drift, we propose a feasible approach named as linear compensation algorithm, which utilizes the linear relationship between the pulse count and temperature to compensate for the pulse count error (ΔN) caused by temperature drift. Experimental results demonstrate that our proposed approach is capable of improving the measurement accuracy and can easily detect sub-100 ppm of hydrogen concentration under variable temperature conditions.

  3. Effect of hydrogen on the integrity of aluminium–oxide interface at elevated temperatures

    KAUST Repository

    Li, Meng; Xie, De-Gang; Ma, Evan; Li, Ju; Zhang, Xixiang; Shan, Zhi-Wei

    2017-01-01

    Hydrogen can facilitate the detachment of protective oxide layer off metals and alloys. The degradation is usually exacerbated at elevated temperatures in many industrial applications; however, its origin remains poorly understood. Here by heating hydrogenated aluminium inside an environmental transmission electron microscope, we show that hydrogen exposure of just a few minutes can greatly degrade the high temperature integrity of metal–oxide interface. Moreover, there exists a critical temperature of ∼150 °C, above which the growth of cavities at the metal–oxide interface reverses to shrinkage, followed by the formation of a few giant cavities. Vacancy supersaturation, activation of a long-range diffusion pathway along the detached interface and the dissociation of hydrogen-vacancy complexes are critical factors affecting this behaviour. These results enrich the understanding of hydrogen-induced interfacial failure at elevated temperatures.

  4. Effect of hydrogen on the integrity of aluminium–oxide interface at elevated temperatures

    KAUST Repository

    Li, Meng

    2017-02-20

    Hydrogen can facilitate the detachment of protective oxide layer off metals and alloys. The degradation is usually exacerbated at elevated temperatures in many industrial applications; however, its origin remains poorly understood. Here by heating hydrogenated aluminium inside an environmental transmission electron microscope, we show that hydrogen exposure of just a few minutes can greatly degrade the high temperature integrity of metal–oxide interface. Moreover, there exists a critical temperature of ∼150 °C, above which the growth of cavities at the metal–oxide interface reverses to shrinkage, followed by the formation of a few giant cavities. Vacancy supersaturation, activation of a long-range diffusion pathway along the detached interface and the dissociation of hydrogen-vacancy complexes are critical factors affecting this behaviour. These results enrich the understanding of hydrogen-induced interfacial failure at elevated temperatures.

  5. Hydrogen yield from low temperature steam reforming of ethanol

    Energy Technology Data Exchange (ETDEWEB)

    Das, N.K.; Dalai, A.K. [Saskatchewan Univ., Saskatoon, SK (Canada). Dept. of Chemical Engineering, Catalysis and Chemical Reaction Engineering Laboratories; Ranganathan, R. [Saskatchewan Research Council, Saskatoon, SK (Canada)

    2007-02-15

    Interest in the use of ethanol for fuel cell hydrogen production was discussed with particular reference to a study in which the production of hydrogen was maximized through low temperature steam reforming of ethanol in the temperature range of 200 to 360 degrees C. The primary objective of this study was to determine the effect of Mn concentration on a Cu/Al{sub 2}O{sub 3} catalyst for steam reforming of ethanol to produce hydrogen. The purpose was to maximize ethanol conversion and hydrogen selectivity in the lowest possible reaction temperature for the ideal catalyst activity. The optimum reaction conditions in the presence of a suitable catalyst can produce the desired products of hydrogen and carbon dioxide. Cu/Al{sub 2}O{sub 3} catalysts with six different concentrations ranging from 0 to 10 weight per cent Mn, were prepared, characterized and studied for the ethanol-steam reforming reaction. The effects of different process variables were studied, including water-to-ethanol feed ratio, space time and catalyst reduction temperatures on ethanol conversion and hydrogen yield. Maximum ethanol conversion of 60.7 per cent and hydrogen yield of 3.74 (mol of hydrogen per mol of ethanol converted) were observed at 360 degrees C for a catalyst with 2.5 weight per cent Mn loading. 29 refs., 3 tabs., 12 figs.

  6. Intermolecular hydrogen bonds: From temperature-driven proton ...

    Indian Academy of Sciences (India)

    Abstract. We have combined neutron scattering and a range of numerical simulations to study hydrogen bonds in condensed matter. Two examples from a recent thesis will be presented. The first concerns proton transfer with increasing temperature in short inter- molecular hydrogen bonds [1,2]. These bonds have unique ...

  7. High temperature refrigerator

    International Nuclear Information System (INIS)

    Steyert, W.A. Jr.

    1978-01-01

    A high temperature magnetic refrigerator is described which uses a Stirling-like cycle in which rotating magnetic working material is heated in zero field and adiabatically magnetized, cooled in high field, then adiabatically demagnetized. During this cycle the working material is in heat exchange with a pumped fluid which absorbs heat from a low temperature heat source and deposits heat in a high temperature reservoir. The magnetic refrigeration cycle operates at an efficiency 70% of Carnot

  8. Quantum Simulations of Low Temperature High Energy Density Matter

    National Research Council Canada - National Science Library

    Voth, Gregory

    2004-01-01

    .... Using classical molecular dynamics simulations to evaluate these equilibrium properties would predict qualitatively incorrect results for low temperature solid hydrogen, because of the highly quantum...

  9. Amide proton temperature coefficients as hydrogen bond indicators in proteins

    International Nuclear Information System (INIS)

    Cierpicki, Tomasz; Otlewski, Jacek

    2001-01-01

    Correlations between amide proton temperature coefficients (Δσ HN /ΔT) and hydrogen bonds were investigated for a data set of 793 amides derived from 14 proteins. For amide protons showing temperature gradients more positive than -4.6 ppb/K there is a hydrogen bond predictivity value exceeding 85%. It increases to over 93% for amides within the range between -4 and -1 ppb/K. Detailed analysis shows an inverse proportionality between amide proton temperature coefficients and hydrogen bond lengths. Furthermore, for hydrogen bonds of similar bond lengths, values of temperature gradients in α-helices are on average 1 ppb/K more negative than in β-sheets. In consequence, a number of amide protons in α-helices involved in hydrogen bonds shorter than 2 A show Δσ HN /ΔT 10 helices and 98% in β-turns have temperature coefficients more positive than -4.6ppb/K. Ring current effect also significantly influences temperature coefficients of amide protons. In seven out of eight cases non-hydrogen bonded amides strongly deshielded by neighboring aromatic rings show temperature coefficients more positive than -2 ppb/K. In general, amide proton temperature gradients do not change with pH unless they correspond to conformational changes. Three examples of pH dependent equilibrium showing hydrogen bond formation at higher pH were found. In conclusion, amide proton temperature coefficients offer an attractive and simple way to confirm existence of hydrogen bonds in NMR determined structures

  10. High-temperature superconductivity

    International Nuclear Information System (INIS)

    Lynn, J.W.

    1990-01-01

    This book discusses development in oxide materials with high superconducting transition temperature. Systems with Tc well above liquid nitrogen temperature are already a reality and higher Tc's are anticipated. The author discusses how the idea of a room-temperature superconductor appears to be a distinctly possible outcome of materials research

  11. Low-temperature diffusion of hydrogen isotopes in tantalum

    International Nuclear Information System (INIS)

    Peichl, R.; Ziegler, P.; Weidinger, A.

    1987-01-01

    The mobility of hydrogen and deuterium in tantalum is investigated in the temperature range between 4.2 and 30 K. On the time scale of the present experiment (25 μs) we find that hydrogen begins to move above 15 K whereas deuterium remains immobile at least up to 30 K. Since the interpretation of the data depends critically on the exact hydrogen configurations a major part of the paper is devoted to this problem. We suggest that hydrogen can exist in fairly localized or more extended states depending on the local homogeneity of the crystal. (orig.)

  12. Preparation and characterization of a nickel/alumina composite membrane for high temperature hydrogen separation. Application in a membrane reactor for the dry reforming of methane; De la synthese d'une membrane composite nikel/ceramique permselective a l'hydrogene au reacteur membranaire. Application au reformage du methane

    Energy Technology Data Exchange (ETDEWEB)

    Haag, St.

    2003-11-01

    The objective of this work was to develop composite inorganic membranes based on nickel or palladium supported on a porous ceramic for high temperature hydrogen separation. These membranes were used in a membrane reactor for the dry reforming of methane in order to shift the chemical equilibrium towards the production of hydrogen and carbon monoxide. The metal layers were deposited on a tubular alumina support by electroless plating. The Ni and the Pd layers are 1 micron thick. The hydrogen permeation tests were done for high temperatures. The Pd/ceramic membrane is permselective to hydrogen and the H{sub 2}/N{sub 2} separation factor (single gas) is 60 at 400 deg C with a transmembrane pressure difference of 1 bar. With a gas mixture, the H{sub 2}/N{sub 2} separation factor is 13. This membrane is not completely dense and the transport mechanism of hydrogen through the Pd layer is mixed: solution-diffusion through the metal bulk and surface diffusion through the defects of the film. However, an embrittlement of the palladium layer under hydrogen atmosphere was observed at 500 deg C. The Ni/ceramic membrane is stable until 600 deg C, its permselectivity to hydrogen increases with the temperature. The use of a sweep gas can provide a H{sub 2}/N{sub 2} separation factor (mixture) of about 25. The main diffusion mechanism is surface diffusion through the pores. Both membranes are not catalytic. Thus, some catalysts composed of nickel and cobalt supported on MgO, SiO{sub 2} or Al{sub 2}O{sub 3} were prepared. These systems allow to reach theoretical limits of conversion calculated for a conventional fixed bed reactor. In the membrane reactor, an enhancement of the methane conversion (15-20%) is observed with both membranes due the selective removal of hydrogen during the reaction. The Ni/ceramic membrane more stable, more permeable and as selective as the palladium one is a brand new material for high temperature hydrogen separation. (author)

  13. Kinetic evidence for the formation of discrete 1,4-dehydrobenzene intermediates. Trapping by inter- and intramolecular hydrogen atom transfer and observation of high-temperature CIDNP

    Energy Technology Data Exchange (ETDEWEB)

    Lockhart, Thomas P. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Univ. of California, Berkeley, CA (United States); California Inst. of Technology (CalTech), Pasadena, CA (United States); Comita, Paul B. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Univ. of California, Berkeley, CA (United States); California Inst. of Technology (CalTech), Pasadena, CA (United States); Bergman, Robert G. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Univ. of California, Berkeley, CA (United States); California Inst. of Technology (CalTech), Pasadena, CA (United States)

    1981-07-01

    Upon heating, alkyl-substituted cis-1,2-diethynyl olefins undergo cyclization to yield reactive 1,4-dehydrobenzenes; the products isolated may be derived from either unimolecular or bimolecular reactions of the intermediate. (Z)-4,5-Diethynyl-4-octene (4) undergoes rearrangement to yield 2,3-di-n-propyl-1,4-dehydrobenzene (17). Solution pyrolysis of 4 in inert aromatic solvents produces three unimolecular products, (Z)-dodeca-4,8-diyn-6-ene (7), benzocyclooctene (9), and o-allyl-n-propylbenzene (10), in high yield. When 1,4-cyclohexadiene is added to the pyrolysis solution as a trapping agent, high yields of the reduced product o-di-n-propylbenzene (12) are obtained. The kinetics of solution pyrolysis of 4 in the presence and absence of trapping agent establish that 2,3-di-n-propyl-1,4-dehydrobenzene is a discrete intermediate on the pathway leading to products. When the reaction was run in the heated probe of an NMR spectrometer, CIDNP was observed in 10. This observation, along with kinetic and chemical trapping evidence, indicates the presence of two additional intermediates, formed from 17 by sequential intramolecular [1,5] hydrogen transfer, on the pathway to products. The observation of CIDNP, coupled with the reactivity exhibited by 17 and the other two intermediates, implicate a biradical description of these molecules. Biradical 17 has been estimated to have a lifetime of about 10-9 s at 200°C and to lie in a well of about 5 kcal/mol with respect to the lowest energy unimolecular pathway ([1,5] hydrogen transfer). Ring opening (expected to be the lowest energy process for 1,4-dehydrobenzenes in which intramolecular hydrogen transfer is unlikely) to the isomeric diethynyl olefin 7 appears to have an activation enthalpy of about 10 kcal/moL Upon thermal reaction in the gas phase (400°C) or in solution in inert solvents (Z)-hexa-2,3-diethyl-1,5-diyn-3-ene (5) rearranges in good yield to the isomeric diethynyl olefin (Z)-deca-3,7-diyn-5-ene (8

  14. Highly efficient high temperature electrolysis

    DEFF Research Database (Denmark)

    Hauch, Anne; Ebbesen, Sune; Jensen, Søren Højgaard

    2008-01-01

    High temperature electrolysis of water and steam may provide an efficient, cost effective and environmentally friendly production of H-2 Using electricity produced from sustainable, non-fossil energy sources. To achieve cost competitive electrolysis cells that are both high performing i.e. minimum...... internal resistance of the cell, and long-term stable, it is critical to develop electrode materials that are optimal for steam electrolysis. In this article electrolysis cells for electrolysis of water or steam at temperatures above 200 degrees C for production of H-2 are reviewed. High temperature...... electrolysis is favourable from a thermodynamic point of view, because a part of the required energy can be supplied as thermal heat, and the activation barrier is lowered increasing the H-2 production rate. Only two types of cells operating at high temperature (above 200 degrees C) have been described...

  15. High temperature superconductors and method

    International Nuclear Information System (INIS)

    Ruvalds, J.J.

    1977-01-01

    This invention comprises a superconductive compound having the formula: Ni/sub 1-x/M/sub x/Z/sub y/ wherein M is a metal which will destroy the magnetic character of nickel (preferably copper, silver or gold); Z is hydrogen or deuterium; x is 0.1 to 0.9; and y, correspondingly, 0.9 to 0.1, and method of conducting electric current with no resistance at relatively high temperature of T>1 0 K comprising a conductor consisting essentially of the superconducting compound noted above

  16. Hydrogen-atom tunneling through a very high barrier; spontaneous thiol → thione conversion in thiourea isolated in low-temperature Ar, Ne, H2 and D2 matrices.

    Science.gov (United States)

    Rostkowska, Hanna; Lapinski, Leszek; Nowak, Maciej J

    2018-05-23

    Spontaneous thiol → thione hydrogen-atom transfer has been investigated for molecules of thiourea trapped in Ar, Ne, normal-H2 (n-H2) and normal-D2 (n-D2) low-temperature matrices. The most stable thione isomer was the only form of the compound present in the matrices after their deposition. According to MP2/6-311++G(2d,p) calculations, the thiol tautomer should be higher in energy by 62.5 kJ mol-1. This less stable thiol form of the compound was photochemically generated in a thione → thiol process, occurring upon UV irradiation of the matrix. Subsequently, a very slow spontaneous conversion of the thiol tautomer into the thione form was observed for the molecules isolated in Ar, Ne, n-H2 and n-D2 matrices kept at 3.5 K and in the dark. Since the thiol → thione transformation in thiourea is a process involving the dissociation of a chemical bond, the barrier for this hydrogen-atom transfer is very high (104-181 kJ mol-1). Crossing such a high potential-energy barrier at a temperature as low as 3.5 K, is possible only by hydrogen-atom tunneling. The experimentally measured time constants of this tunneling process: 52 h (Ar), 76 h (Ne), 94 h (n-H2) and 94 h (n-D2), do not differ much from one another. Hence, the dependence of the tunneling rate on the matrix environment is not drastic. The progress of the thiol → thione conversion was also monitored for Ar matrices at different temperature: 3.5 K, 9 K and 15 K. For this temperature range, the experiments revealed no detectable temperature dependence of the rate of the tunneling process.

  17. Thermoanalytical investigation of the hydrogen absorption behaviour of Sm2Fe17-xGax at high hydrogen pressures

    International Nuclear Information System (INIS)

    Handstein, A.; Kubis, M.; Gebel, B.; Mueller, K.-H.; Schultz, L.; Gutfleisch, O.; Harris, I.R.; Birmingham Univ.

    1998-01-01

    The complete disproportionation of Sm 2 Fe 17-x Ga x during annealing in hydrogen is hindered due to an increased stability of the compounds with a higher Ga content (x ≥ 1). Therefore the HD process as the first step of HDDR (hydrogenation-disproportionation-desorption-recombination) has to be carried out at a high hydrogen pressure for x ≥ 1. The hydrogen absorption behaviour of Sm 2 Fe 17-x Ga x (x = 0, 0.5, 1 and 2) was investigated by means of hydrogen differential thermal analysis (HDTA) and high pressure differential scanning calorimetry (HPDSC) at hydrogen pressures up to 70 bar. A dependency of hydrogenation and disproportionation temperatures on hydrogen pressure and Ga content was found. The comparison with other substituents (M = Al and Si) instead of M = Ga showed an increased stability of Sm 2 Fe 17-x M x compounds against disproportionation by hydrogen in the sequence Al, Ga and Si. The Curie temperatures of the interstitially hydrogenated Th 2 Zn 17 -type materials increase with the hydrogen pressure. In order to produce coercive and thermally stable Sm 2 Fe 15 Ga 2 C y powder by means of the HDDR process, we recombined material disproportionated at different hydrogen pressures. Preliminary results of magnetic properties of this HDDR treated and gas-carburized Sm 2 Fe 15 Ga 2 C y are discussed. (orig.)

  18. High efficiency atomic hydrogen source

    International Nuclear Information System (INIS)

    Lagomarsino, V.; Bassi, D.; Bertok, E.; De Paz, M.; Tommasini, F.

    1974-01-01

    This work presents preliminary results of research intended to produce a M.W. discharge atomic hydrogen source with good dissociation at pressures larger than 10 torr. Analysis of the recombination process at these pressures shows that the volume recombination by three body collisions may be more important than wall recombination or loss of atoms by diffusion and flow outside the discharge region

  19. Hydrogen-Antihydrogen Collisions at Cold Temperatures

    Science.gov (United States)

    Zygelman, Bernard

    2001-05-01

    With the CERN anti-proton de-accelerator now on line, it is anticipated that antihydrogen ( \\overline H) atoms will be created, cooled, and stored in large numbers (M. H. Holzscheitner and M. Charlton, Rep. Prog. Phys. 62),1 (1999). It has recently been proposed that the introduction of cold, spin-polarized, hydrogen atoms into a gas of trapped anti-hydrogen could allow the sympathetic cooling of the anti-hydrogen into the sub-Kelvin regime (P. Froelich, S. Jonsell, A.Saenz, B. Zygelman, and A. Dalgarno, Phys. Rev. Lett. 84), 4577 (2000). In this talk we will present the results of calculations that estimate the rate of elastic scattering of H with \\overline H, and compare that to the rate in which the fragmentation reaction, H + \\overline H arrow p \\overline p + e^+ e^- occurs and limits the utility of sympathetic cooling. Unlike the ground state of the H2 system, the H \\overline H system possesses a non-vanishing electric dipole moment (B. Zygelman, A. Saenz, P. Froelich, S. Jonsell and A. Dalgarno, Phys. Rev. A, in Press (2001).) that allows for the additional inelastic reaction H + \\overline H arrow H\\overline H^* + h ν , where H \\overline H^* is a quasi-bound state of the hydrogen-antihydrogen complex. The rate for radiative association into quasi-bound states of the H \\overline H^* complex will be presented and we will explore the viability for the spectroscopic study of this novel four-body matter-antimatter system. Collaborators in this study include, A. Dalgarno, P. Froelich, A. Saenz and S. Jonsell. I wish to thank the Institute for Theoretical Atomic and Molecular Physics (ITAMP) for their hospitality and support during sabbatical leave where part of this work was done. Partial support was provided by NSF grants to the Smithsonian Institution and Harvard University for ITAMP.

  20. Hydrogen atom temperature measured with wavelength-modulated laser absorption spectroscopy in large scale filament arc negative hydrogen ion source

    International Nuclear Information System (INIS)

    Nakano, H.; Goto, M.; Tsumori, K.; Kisaki, M.; Ikeda, K.; Nagaoka, K.; Osakabe, M.; Takeiri, Y.; Kaneko, O.; Nishiyama, S.; Sasaki, K.

    2015-01-01

    The velocity distribution function of hydrogen atoms is one of the useful parameters to understand particle dynamics from negative hydrogen production to extraction in a negative hydrogen ion source. Hydrogen atom temperature is one of the indicators of the velocity distribution function. To find a feasibility of hydrogen atom temperature measurement in large scale filament arc negative hydrogen ion source for fusion, a model calculation of wavelength-modulated laser absorption spectroscopy of the hydrogen Balmer alpha line was performed. By utilizing a wide range tunable diode laser, we successfully obtained the hydrogen atom temperature of ∼3000 K in the vicinity of the plasma grid electrode. The hydrogen atom temperature increases as well as the arc power, and becomes constant after decreasing with the filling of hydrogen gas pressure

  1. High temperature battery. Hochtemperaturbatterie

    Energy Technology Data Exchange (ETDEWEB)

    Bulling, M.

    1992-06-04

    To prevent heat losses of a high temperature battery, it is proposed to make the incoming current leads in the area of their penetration through the double-walled insulating housing as thermal throttle, particularly spiral ones.

  2. Predictions of glass transition temperature for hydrogen bonding biomaterials.

    Science.gov (United States)

    van der Sman, R G M

    2013-12-19

    We show that the glass transition of a multitude of mixtures containing hydrogen bonding materials correlates strongly with the effective number of hydroxyl groups per molecule, which are available for intermolecular hydrogen bonding. This correlation is in compliance with the topological constraint theory, wherein the intermolecular hydrogen bonds constrain the mobility of the hydrogen bonded network. The finding that the glass transition relates to hydrogen bonding rather than free volume agrees with our recent finding that there is little difference in free volume among carbohydrates and polysaccharides. For binary and ternary mixtures of sugars, polyols, or biopolymers with water, our correlation states that the glass transition temperature is linear with the inverse of the number of effective hydroxyl groups per molecule. Only for dry biopolymer/sugar or sugar/polyol mixtures do we find deviations due to nonideal mixing, imposed by microheterogeneity.

  3. High temperature structural silicides

    International Nuclear Information System (INIS)

    Petrovic, J.J.

    1997-01-01

    Structural silicides have important high temperature applications in oxidizing and aggressive environments. Most prominent are MoSi 2 -based materials, which are borderline ceramic-intermetallic compounds. MoSi 2 single crystals exhibit macroscopic compressive ductility at temperatures below room temperature in some orientations. Polycrystalline MoSi 2 possesses elevated temperature creep behavior which is highly sensitive to grain size. MoSi 2 -Si 3 N 4 composites show an important combination of oxidation resistance, creep resistance, and low temperature fracture toughness. Current potential applications of MoSi 2 -based materials include furnace heating elements, molten metal lances, industrial gas burners, aerospace turbine engine components, diesel engine glow plugs, and materials for glass processing

  4. Optimization of on-line hydrogen stable isotope ratio measurements of halogen- and sulfur-bearing organic compounds using elemental analyzer-chromium/high-temperature conversion isotope ratio mass spectrometry (EA-Cr/HTC-IRMS).

    Science.gov (United States)

    Gehre, Matthias; Renpenning, Julian; Geilmann, Heike; Qi, Haiping; Coplen, Tyler B; Kümmel, Steffen; Ivdra, Natalija; Brand, Willi A; Schimmelmann, Arndt

    2017-03-30

    Accurate hydrogen isotopic analysis of halogen- and sulfur-bearing organics has not been possible with traditional high-temperature conversion (HTC) because the formation of hydrogen-bearing reaction products other than molecular hydrogen (H 2 ) is responsible for non-quantitative H 2 yields and possible hydrogen isotopic fractionation. Our previously introduced, new chromium-based EA-Cr/HTC-IRMS (Elemental Analyzer-Chromium/High-Temperature Conversion Isotope Ratio Mass Spectrometry) technique focused primarily on nitrogen-bearing compounds. Several technical and analytical issues concerning halogen- and sulfur-bearing samples, however, remained unresolved and required further refinement of the reactor systems. The EA-Cr/HTC reactor was substantially modified for the conversion of halogen- and sulfur-bearing samples. The performance of the novel conversion setup for solid and liquid samples was monitored and optimized using a simultaneously operating dual-detection system of IRMS and ion trap MS. The method with several variants in the reactor, including the addition of manganese metal chips, was evaluated in three laboratories using EA-Cr/HTC-IRMS (on-line method) and compared with traditional uranium-reduction-based conversion combined with manual dual-inlet IRMS analysis (off-line method) in one laboratory. The modified EA-Cr/HTC reactor setup showed an overall H 2 -recovery of more than 96% for all halogen- and sulfur-bearing organic compounds. All results were successfully normalized via two-point calibration with VSMOW-SLAP reference waters. Precise and accurate hydrogen isotopic analysis was achieved for a variety of organics containing F-, Cl-, Br-, I-, and S-bearing heteroelements. The robust nature of the on-line EA-Cr/HTC technique was demonstrated by a series of 196 consecutive measurements with a single reactor filling. The optimized EA-Cr/HTC reactor design can be implemented in existing analytical equipment using commercially available material and

  5. Development of high temperature reference electrodes for in-pile application: Part I. Feasibility study of the external pressure balanced Ag/AgCl reference electrode (EPBRE) and the cathodically charged Palladium hydrogen electrode

    International Nuclear Information System (INIS)

    Bosch, R.W.; Van Nieuwenhove, R.

    1998-10-01

    The main problems connected with corrosion potential measurements at elevated temperatures and pressures are related to the stability and lifetime of the reference electrode and the correct estimation of the potential related to the Standard Hydrogen Scale (SHE). Under Pressurised Water Reactor (PWR) conditions of 300 degrees Celsius and 150 bar, the choice of materials is also a limiting factor due to the influence of radiation. Investigations on two reference electrodes that can be used under PWR conditions are reported: the cathodically charged palladium hydrogen electrode, and the external pressure balanced silver/silver chloride electrode. Preliminary investigations with the Pd-electrode were focused on the calculation of the required charging time and the influence of dissolved oxygen. High temperature applications are discussed on the basis of results reported in the literature. Investigations with the silver/silver chloride reference electrode mainly dealt with the salt bridge which is necessary to connect the reference electrode with the testing solution. It is shown that the thermal junction potential is independent of the length of the salt bridge. In addition, the high temperature contributes to an increase of the conductivity of the solution, which is beneficial for the salt bridge connection

  6. An Improved Metal-Packaged Strain Sensor Based on A Regenerated Fiber Bragg Grating in Hydrogen-Loaded Boron–Germanium Co-Doped Photosensitive Fiber for High-Temperature Applications

    Directory of Open Access Journals (Sweden)

    Yun Tu

    2017-02-01

    Full Text Available Local strain measurements are considered as an effective method for structural health monitoring of high-temperature components, which require accurate, reliable and durable sensors. To develop strain sensors that can be used in higher temperature environments, an improved metal-packaged strain sensor based on a regenerated fiber Bragg grating (RFBG fabricated in hydrogen (H2-loaded boron–germanium (B–Ge co-doped photosensitive fiber is developed using the process of combining magnetron sputtering and electroplating, addressing the limitation of mechanical strength degradation of silica optical fibers after annealing at a high temperature for regeneration. The regeneration characteristics of the RFBGs and the strain characteristics of the sensor are evaluated. Numerical simulation of the sensor is conducted using a three-dimensional finite element model. Anomalous decay behavior of two regeneration regimes is observed for the FBGs written in H2-loaded B–Ge co-doped fiber. The strain sensor exhibits good linearity, stability and repeatability when exposed to constant high temperatures of up to 540 °C. A satisfactory agreement is obtained between the experimental and numerical results in strain sensitivity. The results demonstrate that the improved metal-packaged strain sensors based on RFBGs in H2-loaded B–Ge co-doped fiber provide great potential for high-temperature applications by addressing the issues of mechanical integrity and packaging.

  7. Fusion blanket high-temperature heat transfer

    International Nuclear Information System (INIS)

    Fillo, J.A.

    1983-01-01

    Deep penetration of 14 MeV neutrons makes two-temperature region blankets feasible. A relatively low-temperature (approx. 300 0 C) metallic structure is the vacuum/coolant pressure boundary, while the interior of the blanket, which is a simple packed bed of nonstructural material, operates at very high temperatures (>1000 0 C). The water-cooled shell structure is thermally insulated from the steam-cooled interior. High-temperature steam can dramatically increase the efficiency of electric power generation, as well as produce hydrogen and oxygen-based synthetic fuels at high-efficiency

  8. Evidence of superstoichiometric H/D LENR active sites and high-temperature superconductivity in a hydrogen-cycled Pd/PdO

    International Nuclear Information System (INIS)

    Lipson, A.G.; Castano, C.H.; Miley, G.H.; Lyakhov, B.F.; Tsivadze, A.Yu.; Mitin, A.V.

    2006-01-01

    Electron transport and magnetic properties have been studied in a 12.5 μm thick Pd foil with a thermally grown oxide and a low-residual concentration of hydrogen. This foil was deformed by cycling across the Pd hydride miscibility gap and the residual hydrogen was trapped at dislocation cores. Anomalies of both resistance and magnetic susceptibility have been observed below 70 K, indicating the appearance of excess conductivity and a diamagnetic response that we interpret in terms of filamentary superconductivity. These anomalies are attributed to a condensed hydrogen-rich phase at dislocation cores. The role of deuterium rich dislocation cores as LENR active sites is discussed. (author)

  9. Evidence of Superstoichiometric H/d Lenr Active Sites and High-Temperature Superconductivity in a Hydrogen-Cycled Pd/PdO

    Science.gov (United States)

    Lipson, A. G.; Castano, C. H.; Miley, G. H.; Lyakhov, B. F.; Tsivadze, A. Yu.; Mitin, A. V.

    Electron transport and magnetic properties have been studied in a 12.5 μm thick Pd foil with a thermally grown oxide and a low-residual concentration of hydrogen. This foil was deformed by cycling across the Pd hydride miscibility gap and the residual hydrogen was trapped at dislocation cores. Anomalies of both resistance and magnetic susceptibility have been observed below 70 K, indicating the appearance of excess conductivity and a diamagnetic response that we interpret in terms of filamentary superconductivity. These anomalies are attributed to a condensed hydrogen-rich phase at dislocation cores. The role of deuterium rich dislocation cores as LENR active sites is discussed.

  10. Spectroscopic study of low-temperature hydrogen absorption in palladium

    Energy Technology Data Exchange (ETDEWEB)

    Ienaga, K., E-mail: ienaga@issp.u-tokyo.ac.jp; Takata, H.; Onishi, Y.; Inagaki, Y.; Kawae, T. [Department of Applied Quantum Physics, Faculty of Engineering, Kyushu University, Motooka, Nishi-Ku, Fukuoka 819-0395 (Japan); Tsujii, H. [Department of Physics, Faculty of Education, Kanazawa University, Kakuma-machi, Kanazawa 920-1192 (Japan); Kimura, T. [Department of Physics, Kyushu University, Hakozaki, Higashi-Ku, Fukuoka 812-8581 (Japan)

    2015-01-12

    We report real-time detection of hydrogen (H) absorption in metallic palladium (Pd) nano-contacts immersed in liquid H{sub 2} using inelastic electron spectroscopy (IES). After introduction of liquid H{sub 2}, the spectra exhibit the time evolution from the pure Pd to the Pd hydride, indicating that H atoms are absorbed in Pd nano-contacts even at the temperature where the thermal process is not expected. The IES time and bias voltage dependences show that H absorption develops by applying bias voltage 30 ∼ 50 mV, which can be explained by quantum tunneling. The results represent that IES is a powerful method to study the kinetics of high density H on solid surface.

  11. High temperature reaction kinetics

    International Nuclear Information System (INIS)

    Jonah, C.D.; Beno, M.F.; Mulac, W.A.; Bartels, D.

    1985-01-01

    During the last year the dependence of the apparent rate of OD + CO on water pressure was measured at 305, 570, 865 and 1223 K. An explanation was found and tested for the H 2 O dependence of the apparent rate of OH(OD) + CO at high temperatures. The isotope effect for OH(D) with CO was determined over the temperature range 330 K to 1225 K. The reason for the water dependence of the rate of OH(OD) + CO near room temperatures has been investigated but no clear explanation has been found. 1 figure

  12. High-temperature superconductivity

    International Nuclear Information System (INIS)

    Ginzburg, V.L.

    1987-07-01

    After a short account of the history of experimental studies on superconductivity, the microscopic theory of superconductivity, the calculation of the control temperature and its possible maximum value are presented. An explanation of the mechanism of superconductivity in recently discovered superconducting metal oxide ceramics and the perspectives for the realization of new high-temperature superconducting materials are discussed. 56 refs, 2 figs, 3 tabs

  13. Hydrogen utilization international clean energy system technology (WE-NET). Subtask 8. Research and development of hydrogen combustion turbines (development of ultra-high temperature materials); Suiso riyo kokusai clean energy system (WE-NET). Subtask 8. Suiso nensho turbine no kenkyu kaihatsu chokoon zairyo no kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-03-01

    The paper described the result of the fiscal 1996 development of ultra-high temperature materials for parts of hydrogen combustion turbines, as part of the hydrogen utilization technology, which have excellent environmental protectivity and remarkably high efficiency. By the optimized solution heat treatment of monocrystal alloy developed in the previous fiscal year, obtained was strength property the same as the existing super alloys. As to FRC, pore size and strength property of SiC organic hybrid were made clear. ODS alloy cooling blades and heat insulation coating were studied, and YSZ was found to be most excellent as coating material. Concerning intermetallic compounds, the applicability to ultra-high temperatures up to 1700degC was not obtained. For improvement of heat resistance and environment resistance, adopted were highly compacting SiC matrix and BN coatings. Al2O3 was excellent in long-time stability. In the 1600degC steam corrosion test on multiplex structural materials with Al2O3 as surface material, chemical stability was confirmed. Three-dimensional woven fiber reinforced composite materials of C/C{center_dot}CMC were trially produced by changing the fiber orientation, and improvement in ultra-high temperature thermal shock resistance was confirmed. A study was made of spot observation of the specimen surface by laser microscope, and development was conducted of a temperature measuring method with no influence of radiant heat. 44 refs., 250 figs., 40 tabs.

  14. High temperature pipeline design

    Energy Technology Data Exchange (ETDEWEB)

    Greenslade, J.G. [Colt Engineering, Calgary, AB (Canada). Pipelines Dept.; Nixon, J.F. [Nixon Geotech Ltd., Calgary, AB (Canada); Dyck, D.W. [Stress Tech Engineering Inc., Calgary, AB (Canada)

    2004-07-01

    It is impractical to transport bitumen and heavy oil by pipelines at ambient temperature unless diluents are added to reduce the viscosity. A diluted bitumen pipeline is commonly referred to as a dilbit pipeline. The diluent routinely used is natural gas condensate. Since natural gas condensate is limited in supply, it must be recovered and reused at high cost. This paper presented an alternative to the use of diluent to reduce the viscosity of heavy oil or bitumen. The following two basic design issues for a hot bitumen (hotbit) pipeline were presented: (1) modelling the restart problem, and, (2) establishing the maximum practical operating temperature. The transient behaviour during restart of a high temperature pipeline carrying viscous fluids was modelled using the concept of flow capacity. Although the design conditions were hypothetical, they could be encountered in the Athabasca oilsands. It was shown that environmental disturbances occur when the fluid is cooled during shut down because the ground temperature near the pipeline rises. This can change growing conditions, even near deeply buried insulated pipelines. Axial thermal loads also constrain the design and operation of a buried pipeline as higher operating temperatures are considered. As such, strain based design provides the opportunity to design for higher operating temperature than allowable stress based design methods. Expansion loops can partially relieve the thermal stress at a given temperature. As the design temperature increase, there is a point at which above grade pipelines become attractive options, although the materials and welding procedures must be suitable for low temperature service. 3 refs., 1 tab., 10 figs.

  15. Room-temperature ferromagnetism in hydrogenated ZnO nanoparticles

    International Nuclear Information System (INIS)

    Xue, Xudong; Liu, Liangliang; Wang, Zhu; Wu, Yichu

    2014-01-01

    The effect of hydrogen doping on the magnetic properties of ZnO nanoparticles was investigated. Hydrogen was incorporated by annealing under 5% H 2 in Ar ambient at 700 °C. Room-temperature ferromagnetism was induced in hydrogenated ZnO nanoparticles, and the observed ferromagnetism could be switched between “on” and “off” states through hydrogen annealing and oxygen annealing process, respectively. It was found that Zn vacancy and OH bonding complex (V Zn  + OH) was crucial to the observed ferromagnetism by using the X-ray photoelectron spectroscopy and positron annihilation spectroscopy analysis. Based on first-principles calculations, V Zn  + OH was favorable to be presented due to the low formation energy. Meanwhile, this configuration could lead to a magnetic moment of 0.57 μ B . The Raman and photoluminescence measurements excluded the possibility of oxygen vacancy as the origin of the ferromagnetism

  16. Room-temperature ferromagnetism in hydrogenated ZnO nanoparticles

    Science.gov (United States)

    Xue, Xudong; Liu, Liangliang; Wang, Zhu; Wu, Yichu

    2014-01-01

    The effect of hydrogen doping on the magnetic properties of ZnO nanoparticles was investigated. Hydrogen was incorporated by annealing under 5% H2 in Ar ambient at 700 °C. Room-temperature ferromagnetism was induced in hydrogenated ZnO nanoparticles, and the observed ferromagnetism could be switched between "on" and "off" states through hydrogen annealing and oxygen annealing process, respectively. It was found that Zn vacancy and OH bonding complex (VZn + OH) was crucial to the observed ferromagnetism by using the X-ray photoelectron spectroscopy and positron annihilation spectroscopy analysis. Based on first-principles calculations, VZn + OH was favorable to be presented due to the low formation energy. Meanwhile, this configuration could lead to a magnetic moment of 0.57 μB. The Raman and photoluminescence measurements excluded the possibility of oxygen vacancy as the origin of the ferromagnetism.

  17. High temperature storage loop :

    Energy Technology Data Exchange (ETDEWEB)

    Gill, David Dennis; Kolb, William J.

    2013-07-01

    A three year plan for thermal energy storage (TES) research was created at Sandia National Laboratories in the spring of 2012. This plan included a strategic goal of providing test capability for Sandia and for the nation in which to evaluate high temperature storage (>650ÀC) technology. The plan was to scope, design, and build a flow loop that would be compatible with a multitude of high temperature heat transfer/storage fluids. The High Temperature Storage Loop (HTSL) would be reconfigurable so that it was useful for not only storage testing, but also for high temperature receiver testing and high efficiency power cycle testing as well. In that way, HTSL was part of a much larger strategy for Sandia to provide a research and testing platform that would be integral for the evaluation of individual technologies funded under the SunShot program. DOEs SunShot program seeks to reduce the price of solar technologies to 6/kWhr to be cost competitive with carbon-based fuels. The HTSL project sought to provide evaluation capability for these SunShot supported technologies. This report includes the scoping, design, and budgetary costing aspects of this effort

  18. High temperature niobium alloys

    International Nuclear Information System (INIS)

    Wojcik, C.C.

    1991-01-01

    Niobium alloys are currently being used in various high temperature applications such as rocket propulsion, turbine engines and lighting systems. This paper presents an overview of the various commercial niobium alloys, including basic manufacturing processes, properties and applications. Current activities for new applications include powder metallurgy, coating development and fabrication of advanced porous structures for lithium cooled heat pipes

  19. High Temperature Electrolysis

    DEFF Research Database (Denmark)

    Elder, Rachael; Cumming, Denis; Mogensen, Mogens Bjerg

    2015-01-01

    High temperature electrolysis of carbon dioxide, or co-electrolysis of carbon dioxide and steam, has a great potential for carbon dioxide utilisation. A solid oxide electrolysis cell (SOEC), operating between 500 and 900. °C, is used to reduce carbon dioxide to carbon monoxide. If steam is also i...

  20. Study on low temperature plasma driven permeation of hydrogen

    Energy Technology Data Exchange (ETDEWEB)

    Takizawa, Masayuki [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1998-03-01

    It is one of the most important problem in PWI of fusion devices from the point of view of tritium leakage that hydrogen diffuses in the wall of the device and permeates through it, which results in hydrogen being released to the coolant side. In this study, plasma driven permeation experiments were carried out with several kinds of metal membranes in the low temperature plasma where ionic and atomic hydrogen as well as electron existed in order to survey PDP mechanism from the many view points. In addition, incident flux rate from the plasma to the membrane surface was evaluated by calculation analysis. As a result the mechanism of low temperature PDP was found out and described as PDP models. The simulation of the membrane pump system was executed and the system performance was estimated with the models. (author). 135 refs.

  1. Study on low temperature plasma driven permeation of hydrogen

    International Nuclear Information System (INIS)

    Takizawa, Masayuki

    1998-03-01

    It is one of the most important problem in PWI of fusion devices from the point of view of tritium leakage that hydrogen diffuses in the wall of the device and permeates through it, which results in hydrogen being released to the coolant side. In this study, plasma driven permeation experiments were carried out with several kinds of metal membranes in the low temperature plasma where ionic and atomic hydrogen as well as electron existed in order to survey PDP mechanism from the many view points. In addition, incident flux rate from the plasma to the membrane surface was evaluated by calculation analysis. As a result the mechanism of low temperature PDP was found out and described as PDP models. The simulation of the membrane pump system was executed and the system performance was estimated with the models. (author). 135 refs

  2. Room temperature Sieving of Hydrogen Isotopes Using 2-D Materials

    Energy Technology Data Exchange (ETDEWEB)

    Hitchcock, D. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Colon-Mercado, H. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Krentz, T. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Serkiz, S. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Velten, J. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Xiao, S. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2017-09-28

    Hydrogen isotope separation is critical to the DOE’s mission in environmental remediation and nuclear nonproliferation. Isotope separation is also a critical technology for the NNSA, and the ability to perform the separations at room temperature with a relatively small amount of power and space would be a major advancement for their respective missions. Recent work has shown that 2-D materials such as graphene and hexagonal boron nitride can act as an isotopic sieve at room temperature; efficiently separating hydrogen isotopes in water with reported separation ratios of 10:1 for hydrogen: deuterium separation for a single pass. The work performed here suggests that this technique has merit, and furthermore, we are investigating optimization and scale up of the required 2-D material based membranes.

  3. High temperature thermometric phosphors

    Science.gov (United States)

    Allison, Stephen W.; Cates, Michael R.; Boatner, Lynn A.; Gillies, George T.

    1999-03-23

    A high temperature phosphor consists essentially of a material having the general formula LuPO.sub.4 :Dy.sub.(x),Eu.sub.y) wherein: 0.1 wt %.ltoreq.x.ltoreq.20 wt % and 0.1 wt %.ltoreq.y.ltoreq.20 wt %. The high temperature phosphor is in contact with an article whose temperature is to be determined. The article having the phosphor in contact with it is placed in the environment for which the temperature of the article is to be determined. The phosphor is excited by a laser causing the phosphor to fluoresce. The emission from the phosphor is optically focused into a beam-splitting mirror which separates the emission into two separate emissions, the emission caused by the dysprosium dopant and the emission caused by the europium dopent. The separated emissions are optically filtered and the intensities of the emission are detected and measured. The ratio of the intensity of each emission is determined and the temperature of the article is calculated from the ratio of the intensities of the separate emissions.

  4. Sensitivity to temperature of nuclear energy generation by hydrogen burning

    International Nuclear Information System (INIS)

    Mitalas, R.

    1981-01-01

    The sensitivity to temperature of nuclear energy generation by hydrogen burning is discussed. The complexity of the sensitivity is due to the different equilibration time-scales of the constituents of the p-p chain and CN cycle and the dependence of their abundances and time-scales on temperature. The time-scale of the temperature perturbation, compared to the equilibrium time-scale of a constituent, determines whether the constituent is in equilibrium and affects the sensitivity. The temperature sensitivity of the p-p chain for different values of hydrogen abundance, when different constituents come into equilibrium is presented, as well as its variation with 3 He abundance. The temperature sensitivity is drastically different from n 11 , the temperature sensitivity of the proton-proton reaction, unless the time-scale of temperature perturbation is long enough for 3 He to remain in equilibrium. Even in this case the sensitivity of the p-p chain differs significantly from n 11 , unless the temperature is so low that PP II and PP III chains can be neglected. The variation of the sensitivity of CN energy generation is small for different time-scales of temperature variation, because the temperature sensitivities of individual reactions are so similar. The combined sensitivity to temperature of energy generation by hydrogen burning is presented and shown to have a maximum of 16.4 at T 6 = 24.5. For T 6 > 25 the temperature sensitivity is given by the sensitivity of 14 N + p reaction. (author)

  5. High temperature PEM fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Jianlu; Xie, Zhong; Zhang, Jiujun; Tang, Yanghua; Song, Chaojie; Navessin, Titichai; Shi, Zhiqing; Song, Datong; Wang, Haijiang; Wilkinson, David P.; Liu, Zhong-Sheng; Holdcroft, Steven [Institute for Fuel Cell Innovation, National Research Council Canada, Vancouver, BC (Canada V6T 1W5)

    2006-10-06

    There are several compelling technological and commercial reasons for operating H{sub 2}/air PEM fuel cells at temperatures above 100{sup o}C. Rates of electrochemical kinetics are enhanced, water management and cooling is simplified, useful waste heat can be recovered, and lower quality reformed hydrogen may be used as the fuel. This review paper provides a concise review of high temperature PEM fuel cells (HT-PEMFCs) from the perspective of HT-specific materials, designs, and testing/diagnostics. The review describes the motivation for HT-PEMFC development, the technology gaps, and recent advances. HT-membrane development accounts for {approx}90% of the published research in the field of HT-PEMFCs. Despite this, the status of membrane development for high temperature/low humidity operation is less than satisfactory. A weakness in the development of HT-PEMFC technology is the deficiency in HT-specific fuel cell architectures, test station designs, and testing protocols, and an understanding of the underlying fundamental principles behind these areas. The development of HT-specific PEMFC designs is of key importance that may help mitigate issues of membrane dehydration and MEA degradation. (author)

  6. Structural changes and intermolecular interactions of filled ice Ic structure for hydrogen hydrate under high pressure

    International Nuclear Information System (INIS)

    Machida, S; Hirai, H; Kawamura, T; Yamamoto, Y; Yagi, T

    2010-01-01

    High-pressure experiments of hydrogen hydrate were performed using a diamond anvil cell under conditions of 0.1-44.2 GPa and at room temperature. Also, high pressure Raman studies of solid hydrogen were performed in the pressure range of 0.1-43.7 GPa. X-ray diffractometry (XRD) for hydrogen hydrate revealed that a known high-pressure structure, filled ice Ic structure, of hydrogen hydrate transformed to a new high-pressure structure at approximately 35-40 GPa. A comparison of the Raman spectroscopy of a vibron for hydrogen molecules between hydrogen hydrate and solid hydrogen revealed that the extraction of hydrogen molecules from hydrogen hydrate occurred above 20 GPa. Also, the Raman spectra of a roton revealed that the rotation of hydrogen molecules in hydrogen hydrate was suppressed at around 20 GPa and that the rotation recovered under higher pressure. These results indicated that remarkable intermolecular interactions in hydrogen hydrate between neighboring hydrogen molecules and between guest hydrogen molecules and host water molecules might occur. These intermolecular interactions could produce the stability of hydrogen hydrate.

  7. Ovonic Renewable Hydrogen (ORH) - low temperature hydrogen production from renewable fuels

    International Nuclear Information System (INIS)

    Reichman, B.; Mays, W.; Strebe, J.; Fetcenko, M.

    2009-01-01

    'Full text': ECD has developed a new technology to produce hydrogen from various organic matters. In this technology termed Ovonic Renewable Hydrogen (ORH), base material such as NaOH is used as a reactant to facilitate the reforming of the organic matters to hydrogen gas. This Base-Facilitated Reforming (BFR) process is a one-step process and has number of advantages over the conventional steam reforming and gasification processes including lower operation temperature and lower heat consumption. This paper will describe the ORH process and discuss its technological and economics advantages over the conventional hydrogen production processes. ORH process has been studied and demonstrated on variety of renewable fuels including liquid biofuels and solid biomass materials. Results of these studies will be presented. (author)

  8. The effects of incubation period and temperature on the Hydrogen ...

    African Journals Online (AJOL)

    The effects of incubation period and temperature on the Hydrogen sulphide (H 2 S) technique for detection of faecal contamination in water. ... African Journal of Environmental Science and Technology. Journal Home ... A total of 171 water samples from 3 sources were analyzed for the presence of faecal contamination by

  9. Hydrogen - High pressure production and storage

    International Nuclear Information System (INIS)

    Lauretta, J.R

    2005-01-01

    The development of simple, safe and more and more efficient technologies for the production and the storage of hydrogen is necessary condition for the transition towards the economy of hydrogen.In this work the hydrogen production studies experimentally to high pressure by electrolysis of alkaline solutions without the intervention of compressing systems and its direct storage in safe containers.The made tests show that the process of electrolysis to high pressure is feasible and has better yield than to low pressure, and that is possible to solve the operation problems, with relatively simple technology.The preliminary studies and tests indicate that the system container that studied is immune to the outbreak and can have forms and very different sizes, nevertheless, to reach or to surpass the efficiency of storage of the conventional systems the investments necessary will be due to make to be able to produce aluminum alloy tubes of high resistance

  10. Influence of the Ambient Temperature, to the Hydrogen Fuel Cell Functioning

    Directory of Open Access Journals (Sweden)

    POPOVICI Ovidiu

    2012-10-01

    Full Text Available The reversible fuel cell can be used to produce hydrogen. The hydrogen is further the chemical energy source to produce electrical energy using the fuel cell. The ambient temperature will influence theparameters of the hydrogen fuel cell.

  11. Influence of the Ambient Temperature, to the Hydrogen Fuel Cell Functioning

    OpenAIRE

    POPOVICI Ovidiu; HOBLE Dorel Anton

    2012-01-01

    The reversible fuel cell can be used to produce hydrogen. The hydrogen is further the chemical energy source to produce electrical energy using the fuel cell. The ambient temperature will influence theparameters of the hydrogen fuel cell.

  12. Damage process of high purity tungsten coatings by hydrogen beam heat loads

    International Nuclear Information System (INIS)

    Tamura, S.; Tokunaga, K.; Yoshida, N.; Taniguchi, M.; Ezato, K.; Sato, K.; Suzuki, S.; Akiba, M.; Tsunekawa, Y.; Okumiya, M.

    2005-01-01

    To investigate the synergistic effects of heat load and hydrogen irradiation, cyclic heat load tests with a hydrogen beam and a comparable electron beam were performed for high purity CVD-tungsten coatings. Surface modification was examined as a function of the peak temperature by changing the heat flux. Scanning Electron Microscopy analysis showed that the surface damage caused by the hydrogen beam was more severe than that by the electron beam. In the hydrogen beam case, cracking at the surface occurred at all peak temperatures examined from 300 deg. C to 1600 deg. C. These results indicate that the injected hydrogen induces embrittlement for the CVD-tungsten coating

  13. Temperature dependent dual hydrogen sensor response of Pd nanoparticle decorated Al doped ZnO surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Gupta, D.; Barman, P. B.; Hazra, S. K., E-mail: surajithazra@yahoo.co.in [Department of Physics and Materials Science, Jaypee University of Information Technology, Waknaghat, Solan, Himachal Pradesh-173234 (India); Dutta, D. [IC Design and Fabrication Centre, Department of Electronics and Telecommunication Engineering, Jadavpur University, Kolkata-700032 (India); Kumar, M.; Som, T. [SUNAG Laboratory, Institute of Physics, Sachivalaya Marg, Bhubaneswar 751005 (India)

    2015-10-28

    Sputter deposited Al doped ZnO (AZO) thin films exhibit a dual hydrogen sensing response in the temperature range 40 °C–150 °C after surface modifications with palladium nanoparticles. The unmodified AZO films showed no response in hydrogen in the temperature range 40 °C–150 °C. The operational temperature windows on the low and high temperature sides have been estimated by isolating the semiconductor-to-metal transition temperature zone of the sensor device. The gas response pattern was modeled by considering various adsorption isotherms, which revealed the dominance of heterogeneous adsorption characteristics. The Arrhenius adsorption barrier showed dual variation with change in hydrogen gas concentration on either side of the semiconductor-to-metal transition. A detailed analysis of the hydrogen gas response pattern by considering the changes in nano palladium due to hydrogen adsorption, and semiconductor-to-metal transition of nanocrystalline Al doped ZnO layer due to temperature, along with material characterization studies by glancing incidence X-ray diffraction, atomic force microscopy, and transmission electron microscopy, are presented.

  14. High temperature materials characterization

    Science.gov (United States)

    Workman, Gary L.

    1990-01-01

    A lab facility for measuring elastic moduli up to 1700 C was constructed and delivered. It was shown that the ultrasonic method can be used to determine elastic constants of materials from room temperature to their melting points. The ease in coupling high frequency acoustic energy is still a difficult task. Even now, new coupling materials and higher power ultrasonic pulsers are being suggested. The surface was only scratched in terms of showing the full capabilities of either technique used, especially since there is such a large learning curve in developing proper methodologies to take measurements into the high temperature region. The laser acoustic system does not seem to have sufficient precision at this time to replace the normal buffer rod methodology.

  15. Sulfidation/regeneration Multi-cyclic Testing of Fe2O3/Al2O3 Sorbents for the High-temperature Removal of Hydrogen Sulfide.

    Czech Academy of Sciences Publication Activity Database

    Su, Y.-M.; Huang, C.-Y.; Chyou, Y.-P.; Svoboda, Karel

    2017-01-01

    Roč. 74, MAY (2017), s. 89-95 ISSN 1876-1070 R&D Projects: GA ČR GC14-09692J Grant - others:MOST(TW) 103-2923-E-042A-001-MY3; MOST(TW) 102WBS0300011 Institutional support: RVO:67985858 Keywords : desulfurization * hydrogen sulfide * solid sorbent Subject RIV: CI - Industrial Chemistry, Chemical Engineering OBOR OECD: Chemical process engineering Impact factor: 4.217, year: 2016

  16. Hydrogen in trapping states innocuous to environmental degradation of high-strength steels

    International Nuclear Information System (INIS)

    Takai, Kenichi

    2003-01-01

    Hydrogen in trapping states innocuous to environmental degradation of the mechanical properties of high-strength steels has been separated and extracted using thermal desorption analysis (TDA) and slow strain rate test (SSRT). The high-strength steel occluding only hydrogen desorbed at low temperature (peak 1), as determined by TDA, decreases in maximum stress and plastic elongation with increasing occlusion time of peak 1 hydrogen. Thus the trapping state of peak 1 hydrogen is directly associated with environmental degradation. The trap activation energy for peak 1 hydrogen is 23.4 kJ/mol, so the peak 1 hydrogen corresponds to weaker binding states and diffusible states at room temperature. In contrast, the high-strength steel occluding only hydrogen desorbed at high temperature (peak 2), by TDA, maintains the maximum stress and plastic elongation in spite of an increasing content of peak 2 hydrogen. This result indicates that the peak 2 hydrogen trapping state is innocuous to environmental degradation, even though the steel occludes a large amount of peak 2 hydrogen. The trap activation energy for peak 2 hydrogen is 65.0 kJ/mol, which indicates a stronger binding state and nondiffusibility at room temperature. The trap activation energy for peak 2 hydrogen suggests that the driving force energy required for stress-induced, diffusion during elastic and plastic deformation, and the energy required for hydrogen dragging by dislocation mobility during plastic deformation are lower than the binding energy between hydrogen and trapping sites. The peak 2 hydrogen, therefore, is believed to not accumulate in front of the crack tip and to not cause environmental degradation in spite of being present in amounts as high as 2.9 mass ppm. (author)

  17. High temperature radioisotope capsule

    International Nuclear Information System (INIS)

    Bradshaw, G.B.

    1976-01-01

    A high temperature radioisotope capsule made up of three concentric cylinders, with the isotope fuel located within the innermost cylinder is described. The innermost cylinder has hemispherical ends and is constructed of a tantalum alloy. The intermediate cylinder is made of a molybdenum alloy and is capable of withstanding the pressure generated by the alpha particle decay of the fuel. The outer cylinder is made of a platinum alloy of high resistance to corrosion. A gas separates the innermost cylinder from the intermediate cylinder and the intermediate cylinder from the outer cylinder

  18. High-temperature uncertainty

    International Nuclear Information System (INIS)

    Timusk, T.

    2005-01-01

    Recent experiments reveal that the mechanism responsible for the superconducting properties of cuprate materials is even more mysterious than we thought. Two decades ago, Georg Bednorz and Alex Mueller of IBM's research laboratory in Zurich rocked the world of physics when they discovered a material that lost all resistance to electrical current at the record temperature of 36 K. Until then, superconductivity was thought to be a strictly low-temperature phenomenon that required costly refrigeration. Moreover, the IBM discovery - for which Bednorz and Mueller were awarded the 1987 Nobel Prize for Physics - was made in a ceramic copper-oxide material that nobody expected to be particularly special. Proposed applications for these 'cuprates' abounded. High-temperature superconductivity, particularly if it could be extended to room temperature, offered the promise of levitating trains, ultra-efficient power cables, and even supercomputers based on superconducting quantum interference devices. But these applications have been slow to materialize. Moreover, almost 20 years on, the physics behind this strange state of matter remains a mystery. (U.K.)

  19. Empirical Method to Estimate Hydrogen Embrittlement of Metals as a Function of Hydrogen Gas Pressure at Constant Temperature

    Science.gov (United States)

    Lee, Jonathan A.

    2010-01-01

    High pressure Hydrogen (H) gas has been known to have a deleterious effect on the mechanical properties of certain metals, particularly, the notched tensile strength, fracture toughness and ductility. The ratio of these properties in Hydrogen as compared to Helium or Air is called the Hydrogen Environment Embrittlement (HEE) Index, which is a useful method to classify the severity of H embrittlement and to aid in the material screening and selection for safety usage H gas environment. A comprehensive world-wide database compilation, in the past 50 years, has shown that the HEE index is mostly collected at two conveniently high H pressure points of 5 ksi and 10 ksi near room temperature. Since H embrittlement is directly related to pressure, the lack of HEE index at other pressure points has posed a technical problem for the designers to select appropriate materials at a specific H pressure for various applications in aerospace, alternate and renewable energy sectors for an emerging hydrogen economy. Based on the Power-Law mathematical relationship, an empirical method to accurately predict the HEE index, as a function of H pressure at constant temperature, is presented with a brief review on Sievert's law for gas-metal absorption.

  20. Room-temperature synthesis of Zn(0.80)Cd(0.20)S solid solution with a high visible-light photocatalytic activity for hydrogen evolution.

    Science.gov (United States)

    Wang, Dong-Hong; Wang, Lei; Xu, An-Wu

    2012-03-21

    Visible light photocatalytic H(2) production from water splitting is of great significance for its potential applications in converting solar energy into chemical energy. In this study, a series of Zn(1-x)Cd(x)S solid solutions with a nanoporous structure were successfully synthesized via a facile template-free method at room temperature. The obtained solid solutions were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), ultraviolet-visible (UV-vis) diffuse reflectance spectroscopy, X-ray photoelectron spectroscopy (XPS), energy-dispersive X-ray spectroscopy (EDS) and N(2) adsorption-desorption analysis. The solid solutions show efficient photocatalytic activity for H(2) evolution from aqueous solutions containing sacrificial reagents S(2-) and SO(3)(2-) under visible-light irradiation without a Pt cocatalyst, and loading of the Pt cocatalyst further improves the visible-light photocatalytic activity. The optimal photocatalyst with x = 0.20 prepared at pH = 7.3 displays the highest activity for H(2) evolution. The bare and 0.25 wt% Pt loaded Zn(0.80)Cd(0.20)S nanoparticles exhibit a high H(2) evolution rate of 193 μmol h(-1) and 458 μmol h(-1) under visible-light irradiation (λ ≥ 420 nm), respectively. In addition, the bare and 0.25 wt% Pt loaded Zn(0.80)Cd(0.20)S catalysts show a high H(2) evolution rate of 252 and 640 μmol h(-1) under simulated solar light irradiation, respectively. Moreover, the Zn(0.80)Cd(0.20)S catalyst displays a high photocatalytic stability for H(2) evolution under long-term light irradiation. The incorporation of Cd in the solid solution leads to the visible light absorption, and the high content of Zn in the solid solution results in a relatively negative conduction band, a modulated band gap and a rather wide valence bandwidth, which are responsible for the excellent photocatalytic performance of H(2) production and for the high photostability

  1. High Temperature Piezoelectric Drill

    Science.gov (United States)

    Bao, Xiaoqi; Bar-Cohen, Yoseph; Sherrit, Stewart; Badescu, Mircea; Shrout, Tom

    2012-01-01

    Venus is one of the planets in the solar systems that are considered for potential future exploration missions. It has extreme environment where the average temperature is 460 deg C and its ambient pressure is about 90 atm. Since the existing actuation technology cannot maintain functionality under the harsh conditions of Venus, it is a challenge to perform sampling and other tasks that require the use of moving parts. Specifically, the currently available electromagnetic actuators are limited in their ability to produce sufficiently high stroke, torque, or force. In contrast, advances in developing electro-mechanical materials (such as piezoelectric and electrostrictive) have enabled potential actuation capabilities that can be used to support such missions. Taking advantage of these materials, we developed a piezoelectric actuated drill that operates at the temperature range up to 500 deg C and the mechanism is based on the Ultrasonic/Sonic Drill/Corer (USDC) configuration. The detailed results of our study are presented in this paper

  2. Importance of temperature, pH, and boric acid concentration on rates of hydrogen production from galvanized steel corrosion

    International Nuclear Information System (INIS)

    Loyola, V.M.

    1982-01-01

    One of the known sources of hydrogen gas within a nuclear plant containment building during a LOCA is the high temperature corrosion of galvanized steel yielding hydrogen gas. The importance of this source of hydrogen will vary depending on the severity of the accident. In an accident which resulted in core degradation, for example, the major source of hydrogen would probably be the metal-water reaction of the zircaloy cladding, and the corrosion of galvanized steel would then become a relatively minor source of hydrogen. However, in an accident in which core degradation is avoided or limited to minor damage, the corrosion of galvanized steel, and presumably of other materials as well, would then become a major contributor to the buildup of hydrogen within containment. The purpose of this paper is to present the overall effects of temperature, pH, and boric acid concentration on the rate of hydrogen generation over a broad range of each parameter

  3. High Capacity Hydrogen Storage on Nanoporous Biocarbon

    Science.gov (United States)

    Burress, Jacob; Wood, Mikael; Gordon, Michael; Parilla, Phillip; Benham, Michael; Wexler, Carlos; Hawthorne, Fred; Pfeifer, Peter

    2008-03-01

    The Alliance for Collaborative Research in Alternative Fuel Technology (http://all-craft.missouri.edu) has been optimizing nanoporous biocarbon for high capacity hydrogen storage. The hydrogen storage was measured gravimetrically and volumetrically (Sievert's apparatus). These measurements have been validated by NREL and Hiden Isochema. Sample S-33/k, our current best performer, stores 73-91 g H2/kg carbon at 77 K and 47 bar, and 1.0-1.6 g H2/kg carbon at 293 K and 47 bar. Hydrogen isotherms run by Hiden Isochema have given experimental binding energies of 8.8 kJ/mol compared to the binding energy of graphite of 5 kJ/mol. Results from a novel boron doping technique will also be presented. The benefits and validity of using boron-doping on carbon will also be discussed.

  4. High temperature materials and mechanisms

    CERN Document Server

    2014-01-01

    The use of high-temperature materials in current and future applications, including silicone materials for handling hot foods and metal alloys for developing high-speed aircraft and spacecraft systems, has generated a growing interest in high-temperature technologies. High Temperature Materials and Mechanisms explores a broad range of issues related to high-temperature materials and mechanisms that operate in harsh conditions. While some applications involve the use of materials at high temperatures, others require materials processed at high temperatures for use at room temperature. High-temperature materials must also be resistant to related causes of damage, such as oxidation and corrosion, which are accelerated with increased temperatures. This book examines high-temperature materials and mechanisms from many angles. It covers the topics of processes, materials characterization methods, and the nondestructive evaluation and health monitoring of high-temperature materials and structures. It describes the ...

  5. Adsorption and temperature-programmed desorption of hydrogen with dispersed platinum and platinum-gold catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, J.R.; Foger, K.; Breakspere, R.J.

    1979-05-01

    Adsorption and temperature-programmed desorption of hydrogen with dispersed platinum and platinum-gold catalysts was studied with 0.9-3Vertical Bar3< platinum on silica gel, aerosil, sodium and lanthanum Y zeolites, and ..gamma..-alumina, and on aerosil-supported gold-platinum alloys containing 2, 10, 24, 33, and 85Vertical Bar3< gold. Surface enrichment with gold in the alloy systems, as derived from hydrogen adsorption data and predicted from surface enrichment theory and electron microscopic measurements of particle size, were in good agreement, which indicated that equilibrium was achieved by the thermal treatment (oxygen at 573/sup 0/K, hydrogen at 620/sup 0/K, repeated cycles) used. Hydrogen spillover to gold was observed at the higher hydrogen pressures tested on the alloys with high gold content, and to the zeolite supports. The temperature-programed desorption profiles were independent of gold content, which indicated that gold acts only as diluent, and that isolated surface platinum atoms become populated with hydrogen atoms either by hydrogen atom spillover from platinum ensembles to gold and from the gold to the isolated platinum, and/or by adsorption of a molecule directly on the isolated platinum and chemisorption of one H atom at an adjacent gold atom. The distribution of surface platinum ensembles was evaluated by a computer simulation method.

  6. Ultra-high temperature direct propulsion

    International Nuclear Information System (INIS)

    Araj, K.J.; Slovik, G.; Powell, J.R.; Ludewig, H.

    1987-01-01

    Potential advantages of ultra-high exhaust temperature (3000 K - 4000 K) direct propulsion nuclear rockets are explored. Modifications to the Particle Bed Reactor (PBR) to achieve these temperatures are described. Benefits of ultra-high temperature propulsion are discussed for two missions - orbit transfer (ΔV = 5546 m/s) and interplanetary exploration (ΔV = 20000 m/s). For such missions ultra-high temperatures appear to be worth the additional complexity. Thrust levels are reduced substantially for a given power level, due to the higher enthalpy caused by partial disassociation of the hydrogen propellant. Though technically challenging, it appears potentially feasible to achieve such ultra high temperatures using the PBR

  7. Synthesis and stability of hydrogen selenide compounds at high pressure

    Energy Technology Data Exchange (ETDEWEB)

    Pace, Edward J.; Binns, Jack; Alvarez, Miriam Pena; Dalladay-Simpson, Philip; Gregoryanz, Eugene; Howie, Ross T. (Edinburgh); (CHPSTAR- China)

    2017-11-14

    The observation of high-temperature superconductivity in hydride sulfide (H2S) at high pressures has generated considerable interest in compressed hydrogen-rich compounds. High-pressure hydrogen selenide (H2Se) has also been predicted to be superconducting at high temperatures; however, its behaviour and stability upon compression remains unknown. In this study, we synthesize H2Se in situ from elemental Se and molecular H2 at pressures of 0.4 GPa and temperatures of 473 K. On compression at 300 K, we observe the high-pressure solid phase sequence (I-I'-IV) of H2Se through Raman spectroscopy and x-ray diffraction measurements, before dissociation into its constituent elements. Through the compression of H2Se in H2 media, we also observe the formation of a host-guest structure, (H2Se)2H2, which is stable at the same conditions as H2Se, with respect to decomposition. These measurements show that the behaviour of H2Se is remarkably similar to that of H2S and provides further understanding of the hydrogen chalcogenides under pressure.

  8. Preliminary risk analysis of an Hydrogen production plant using the reformed process of methane with vapor coupled to a high temperature nuclear reactor

    International Nuclear Information System (INIS)

    Flores y Flores, A.; Nelson E, P.F.; Francois L, J.L.

    2004-01-01

    It is necessary to identify the different types of dangers, as well as their causes, probabilities and consequences of the same ones, inside plants, industries and any process to classify the risks. This work is focused in particular to a study using the technical HAZOP (Hazard and Operability) for a plant of reformed of methane with vapor coupled to a nuclear reactor of the type HTTR (High Temperature Test Reactor), which is designed to be built in Japan. In particular in this study the interaction is analyzed between the nuclear reactor and the plant of reformed of methane with vapor. After knowing the possible causes of risk one it is built chart of results of HAZOP to have a better vision of the consequences of this faults toward the buildings and constructions, to people and the influence of the fault on each plant; for what there are proposed solutions to mitigate these consequences or to avoid them. The work is divided in three sections: a brief introduction about the technique of HAZOP; some important aspects of the plant of reformed of methane with vapor; and the construction of the chart of results of HAZOP. (Author)

  9. High temperature superconductors

    CERN Document Server

    Paranthaman, Parans

    2010-01-01

    This essential reference provides the most comprehensive presentation of the state of the art in the field of high temperature superconductors. This growing field of research and applications is currently being supported by numerous governmental and industrial initiatives in the United States, Asia and Europe to overcome grid energy distribution issues. The technology is particularly intended for densely populated areas. It is now being commercialized for power-delivery devices, such as power transmission lines and cables, motors and generators. Applications in electric utilities include current limiters, long transmission lines and energy-storage devices that will help industries avoid dips in electric power.

  10. Chemical equilibria relating the isotopic hydrogens at low temperatures

    International Nuclear Information System (INIS)

    Pyper, J.W.; Souers, P.C.

    1976-01-01

    Hydrogen fusion will require a fuel mixture of liquefied or frozen D 2 and T 2 . The composition of this fuel mixture is described by the equilibrium constant K/sub DT/. The theory of isotopic exchange reactions is discussed as applied to the hydrogen isotopes. A literature survey of the values of K/sub HD/, K/sub HT/, and K/sub DT/ found no values of K/sub DT/ for temperatures below 25 0 K and no values of K/sub HD/ and K/sub HT/ for temperatures below 50 0 K. The existing data are critically evaluated, and simplified formulas for the three equilibrium constants in the temperature range 50 to 300 0 K are derived from them. Harmonic approximation theory with rotational correction was used to calculate values of K/sub HD/, K/sub HT/, and K/sub DT/ in the temperature range 4.2 to 50 0 K. It is found that K/sub DT/ = 2.995 exp(-10.82/T) in the temperature range 16.7 to 33.3 0 K to an accuracy of 1%. Tables, graphs, and equations of K/sub HD/, K/sub HT/, and K/sub DT/ are given for the temperature range 4.2 to 50 0 K. 27 references, 14 tables, 8 figures

  11. Very High Energy Neutron Scattering from Hydrogen

    International Nuclear Information System (INIS)

    Cowley, R A; Stock, C; Bennington, S M; Taylor, J; Gidopoulos, N I

    2010-01-01

    The neutron scattering from hydrogen in polythene has been measured with the direct time-of flight spectrometer, MARI, at the ISIS facility of the Rutherford Appleton Laboratory with incident neutron energies between 0.5 eV and 600 eV. The results of experiments using the spectrometer, VESUVIO, have given intensities from hydrogen containing materials that were about 60% of the intensity expected from hydrogen. Since VESUVIO is the only instrument in the world that routinely operates with incident neutron energies in the eV range we have chosen to measure the scattering from hydrogen at high incident neutron energies with a different type of instrument. The MARI, direct time-of-flight, instrument was chosen for the experiment and we have studied the scattering for several different incident neutron energies. We have learnt how to subtract the gamma ray background, how to calibrate the incident energy and how to convert the spectra to an energy plot . The intensity of the hydrogen scattering was independent of the scattering angle for scattering angles from about 5 degrees up to 70 degrees for at least 3 different incident neutron energies between 20 eV and 100 eV. When the data was put on an absolute scale, by measuring the scattering from 5 metal foils with known thicknesses under the same conditions we found that the absolute intensity of the scattering from the hydrogen was in agreement with that expected to an accuracy of ± 5.0% over a wide range of wave-vector transfers between 1 and 250 A -1 . These measurements show that it is possible to measure the neutron scattering with incident neutron energies up to at least 100 eV with a direct geometry time-of-flight spectrometer and that the results are in agreement with conventional scattering theory.

  12. High temperature ceramic-tubed reformer

    Science.gov (United States)

    Williams, Joseph J.; Rosenberg, Robert A.; McDonough, Lane J.

    1990-03-01

    The overall objective of the HiPHES project is to develop an advanced high-pressure heat exchanger for a convective steam/methane reformer. The HiPHES steam/methane reformer is a convective, shell and tube type, catalytic reactor. The use of ceramic tubes will allow reaction temperature higher than the current state-of-the-art outlet temperatures of about 1600 F using metal tubes. Higher reaction temperatures increase feedstock conversion to synthesis gas and reduce energy requirements compared to currently available radiant-box type reformers using metal tubes. Reforming of natural gas is the principal method used to produce synthesis gas (primarily hydrogen and carbon monoxide, H2 and CO) which is used to produce hydrogen (for refinery upgrading), methanol, as well as several other important materials. The HiPHES reformer development is an extension of Stone and Webster's efforts to develop a metal-tubed convective reformer integrated with a gas turbine cycle.

  13. Vanadium alloy membranes for high hydrogen permeability and suppressed hydrogen embrittlement

    International Nuclear Information System (INIS)

    Kim, Kwang Hee; Park, Hyeon Cheol; Lee, Jaeho; Cho, Eunseog; Lee, Sang Mock

    2013-01-01

    The structural properties and hydrogen permeation characteristics of ternary vanadium–iron–aluminum (V–Fe–Al) alloy were investigated. To achieve not only high hydrogen permeability but also strong resistance to hydrogen embrittlement, the alloy composition was modulated to show high hydrogen diffusivity but reduced hydrogen solubility. We demonstrated that matching the lattice constant to the value of pure V by co-alloying lattice-contracting and lattice-expanding elements was quite effective in maintaining high hydrogen diffusivity of pure V

  14. High temperature interface superconductivity

    International Nuclear Information System (INIS)

    Gozar, A.; Bozovic, I.

    2016-01-01

    Highlight: • This review article covers the topic of high temperature interface superconductivity. • New materials and techniques used for achieving interface superconductivity are discussed. • We emphasize the role played by the differences in structure and electronic properties at the interface with respect to the bulk of the constituents. - Abstract: High-T_c superconductivity at interfaces has a history of more than a couple of decades. In this review we focus our attention on copper-oxide based heterostructures and multi-layers. We first discuss the technique, atomic layer-by-layer molecular beam epitaxy (ALL-MBE) engineering, that enabled High-T_c Interface Superconductivity (HT-IS), and the challenges associated with the realization of high quality interfaces. Then we turn our attention to the experiments which shed light on the structure and properties of interfacial layers, allowing comparison to those of single-phase films and bulk crystals. Both ‘passive’ hetero-structures as well as surface-induced effects by external gating are discussed. We conclude by comparing HT-IS in cuprates and in other classes of materials, especially Fe-based superconductors, and by examining the grand challenges currently laying ahead for the field.

  15. Hydrogen diffusion at moderate temperatures in p-type Czochralski silicon

    International Nuclear Information System (INIS)

    Huang, Y.L.; Ma, Y.; Job, R.; Ulyashin, A.G.

    2004-01-01

    In plasma-hydrogenated p-type Czochralski silicon, rapid thermal donor (TD) formation is achieved, resulting from the catalytic support of hydrogen. The n-type counter doping by TD leads to a p-n junction formation. A simple method for the indirect determination of the diffusivity of hydrogen via applying the spreading resistance probe measurements is presented. Hydrogen diffusion in silicon during both plasma hydrogenation and post-hydrogenation annealing is investigated. The impact of the hydrogenation duration, annealing temperature, and resistivity of the silicon wafers on the hydrogen diffusion is discussed. Diffusivities of hydrogen are determined in the temperature range 270-450 deg. C. The activation energy for the hydrogen diffusion is deduced to be 1.23 eV. The diffusion of hydrogen is interpreted within the framework of a trap-limited diffusion mechanism. Oxygen and hydrogen are found to be the main traps

  16. Superconductivity in hydrogen-rich materials at high pressures

    Energy Technology Data Exchange (ETDEWEB)

    Drozdov, Alexander

    2016-07-01

    A room temperature superconductor is probably one of the most desired systems in solid state physics. The highest critical temperature (T{sub c}) that has been achieved so far is in the copper oxide system: 133 kelvin (K) at ambient pressure ([82]Schilling et al. 1993) and 160 K under pressure ([42]Gao et al. 1994). The nature of superconductivity in the cuprates and in the recently discovered iron-based superconductor family (T{sub c}=57 K) is still not fully understood. In contrast, there is a class of superconductors which is well-described by the Bardeen, Cooper, Schrieffer (BCS) theory - conventional superconductors. Great efforts were spent in searching for high-temperature (T{sub c} > 77 K) conventional superconductor but only T{sub c} = 39 K has been reached in MgB2 ([68]Nagamatsu et al. 2001). BCS theory puts no bounds for T{sub c} as follows from Eliashberg's formulation of BCS theory. T{sub c} can be high, if there is a favorable combination of high-frequency phonons, strong electron-phonon coupling, and a high density of states. It does not predict however in which materials all three parameters are large. At least it gives a clear indication that materials with light elements are favorable as light elements provide high frequencies in the phonon spectrum. The lightest element is hydrogen, and Ashcroft made a first prediction that metallic hydrogen will be a high-temperature superconductor ([6]Ashcroft 1968). As pressure of hydrogen metallization was too high (about 400-500 GPa) for experimental techniques then he proposed that compounds dominated by hydrogen (hydrides) also might be good high temperature superconductors ([6]Ashcroft 1968; [7]Ashcroft 2004). A lot of the followed calculations supported this idea. T{sub c} in the range of 50-235 kelvin was predicted for many hydrides. Unfortunately, only a moderate T{sub c} of 17 kelvin has been observed experimentally ([27]Eremets et al. 2008) so far. A goal of the present work is to find a

  17. FY 1974 report on the results of the Sunshine Project. R and D of hydrogen production technology by the high-temperature/high-pressure water electrolysis method (outline); 1974 nendo koon koatsusui denkaiho ni yoru suiso seizo gijutsu no kenkyu kaihatsu seika hokokusho. Gaiyo

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1985-05-30

    As the R and D of hydrogen production technology by the high-temperature/high pressure water electrolysis method, this paper outlined (1) the concept design and the investigational research on the constant load type high-temperature/high-pressure (multi-pole type) diaphragm water electrolysis tank (in charge of Mitsubishi Kakoki Kaisha, Ltd.); (2) the concept design and the investigational research on the load variation type high-temperature/high-pressure diaphragm water electrolysis equipment (in charge of Showa Denko K.K. and Hitachi Zosen Corp.); (3) the investigational research on the role of water electrolysis in various primary energy sources and the evaluation (in charge of Mitsubishi Research Institute Inc.). In (1), the concept design of a small test plant was made, and the detailed design and test plan on the material test equipment were drew up. In (2), Showa Denko K.K. is running the water electrolysis plant. As a result of studying the electric power unit and operational conditions of hydrogen production, it was concluded that high-temperature/high-pressure operation should be tried for making the water electrolysis tank highly efficient. Hitachi Zosen Corp. made the study of the multi-pole type pressurized filter system high-pressure water electrolysis equipment which was developed for submarine and the design of the bubble behavior observing tank and material test tank for the concept design of load variation type test plant. (NEDO)

  18. Temperature-dependent absorption cross sections for hydrogen peroxide vapor

    Science.gov (United States)

    Nicovich, J. M.; Wine, P. H.

    1988-01-01

    Relative absorption cross sections for hydrogen peroxide vapor were measured over the temperature ranges 285-381 K for lambda = 230 nm-295 nm and 300-381 K for lambda = 193 nm-350 nm. The well established 298 K cross sections at 202.6 and 228.8 nm were used as an absolute calibration. A significant temperature dependence was observed at the important tropospheric photolysis wavelengths lambda over 300 nm. Measured cross sections were extrapolated to lower temperatures, using a simple model which attributes the observed temperature dependence to enhanced absorption by molecules possessing one quantum of O-O stretch vibrational excitation. Upper tropospheric photodissociation rates calculated using the extrapolated cross sections are about 25 percent lower than those calculated using currently recommended 298 K cross sections.

  19. High temperature metallic recuperator

    Science.gov (United States)

    Ward, M. E.; Solmon, N. G.; Smeltzer, C. E.

    1981-06-01

    An industrial 4.5 MM Btu/hr axial counterflow recuperator, fabricated to deliver 1600 F combustion air, was designed to handle rapid cyclic loading, a long life, acceptable costs, and a low maintenance requirement. A cost benefit anlysis of a high temperature waste heat recovery system utilizing the recurperator and components capable of 1600 F combustion air preheat shows that this system would have a payback period of less than two years. Fifteen companies and industrial associations were interviewed and expressed great interest in recuperation in large energy consuming industries. Determination of long term environmental effects on candidate recuperator tubing alloys was completed. Alloys found to be acceptable in the 2200 F flue gas environment of a steel billet reheat furnace, were identified.

  20. Room-temperature ferromagnetism in hydrogenated ZnO nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Xue, Xudong; Liu, Liangliang; Wang, Zhu; Wu, Yichu, E-mail: ycwu@whu.edu.cn [School of Physics and Technology, Hubei Nuclear Solid Physics Key Laboratory, Wuhan University, Wuhan 430072 (China)

    2014-01-21

    The effect of hydrogen doping on the magnetic properties of ZnO nanoparticles was investigated. Hydrogen was incorporated by annealing under 5% H{sub 2} in Ar ambient at 700 °C. Room-temperature ferromagnetism was induced in hydrogenated ZnO nanoparticles, and the observed ferromagnetism could be switched between “on” and “off” states through hydrogen annealing and oxygen annealing process, respectively. It was found that Zn vacancy and OH bonding complex (V{sub Zn} + OH) was crucial to the observed ferromagnetism by using the X-ray photoelectron spectroscopy and positron annihilation spectroscopy analysis. Based on first-principles calculations, V{sub Zn} + OH was favorable to be presented due to the low formation energy. Meanwhile, this configuration could lead to a magnetic moment of 0.57 μ{sub B}. The Raman and photoluminescence measurements excluded the possibility of oxygen vacancy as the origin of the ferromagnetism.

  1. Dynamic Model of High Temperature PEM Fuel Cell Stack Temperature

    DEFF Research Database (Denmark)

    Andreasen, Søren Juhl; Kær, Søren Knudsen

    2007-01-01

    cathode air cooled 30 cell HTPEM fuel cell stack developed at the Institute of Energy Technology at Aalborg University. This fuel cell stack uses PEMEAS Celtec P-1000 membranes, runs on pure hydrogen in a dead end anode configuration with a purge valve. The cooling of the stack is managed by running......The present work involves the development of a model for predicting the dynamic temperature of a high temperature PEM (HTPEM) fuel cell stack. The model is developed to test different thermal control strategies before implementing them in the actual system. The test system consists of a prototype...... the stack at a high stoichiometric air flow. This is possible because of the PBI fuel cell membranes used, and the very low pressure drop in the stack. The model consists of a discrete thermal model dividing the stack into three parts: inlet, middle and end and predicting the temperatures in these three...

  2. Substrate temperature dependence of microcrystallinity in plasma-deposited, boron-doped hydrogenated silicon alloys

    International Nuclear Information System (INIS)

    Rajeswaran, G.; Kampas, F.J.; Vanier, P.E.; Sabatini, R.L.; Tafto, J.

    1983-01-01

    The glow-discharge decomposition of silane diluted in hydrogen using diborane as a dopant results in the deposition of p-type microcrystalline silicon films at relatively low temperatures. The conductivity of these films is critically dependent on the substrate temperature when the ratio of silane flow rate to total gas flow rate is 1%. Electron micrographs show that highly conducting films contain numerous clusters of 2.5-nm crystallites that are embedded in an amorphous medium

  3. HIGH EFFICIENCY GENERATION OF HYDROGEN FUELS USING NUCLEAR POWER

    Energy Technology Data Exchange (ETDEWEB)

    BROWN,LC; BESENBRUCH,GE; LENTSCH,RD; SCHULTZ,KR; FUNK,JF; PICKARD,PS; MARSHALL,AC; SHOWALTER,SK

    2003-06-01

    OAK B202 HIGH EFFICIENCY GENERATION OF HYDROGEN FUELS USING NUCLEAR POWER. Combustion of fossil fuels, used to power transportation, generate electricity, heat homes and fuel industry provides 86% of the world's energy. Drawbacks to fossil fuel utilization include limited supply, pollution, and carbon dioxide emissions. Carbon dioxide emissions, thought to be responsible for global warming, are now the subject of international treaties. Together, these drawbacks argue for the replacement of fossil fuels with a less-polluting potentially renewable primary energy such as nuclear energy. Conventional nuclear plants readily generate electric power but fossil fuels are firmly entrenched in the transportation sector. Hydrogen is an environmentally attractive transportation fuel that has the potential to displace fossil fuels. Hydrogen will be particularly advantageous when coupled with fuel cells. Fuel cells have higher efficiency than conventional battery/internal combustion engine combinations and do not produce nitrogen oxides during low-temperature operation. Contemporary hydrogen production is primarily based on fossil fuels and most specifically on natural gas. When hydrogen is produced using energy derived from fossil fuels, there is little or no environmental advantage. There is currently no large scale, cost-effective, environmentally attractive hydrogen production process available for commercialization, nor has such a process been identified. The objective of this work is to find an economically feasible process for the production of hydrogen, by nuclear means, using an advanced high-temperature nuclear reactor as the primary energy source. Hydrogen production by thermochemical water-splitting (Appendix A), a chemical process that accomplishes the decomposition of water into hydrogen and oxygen using only heat or, in the case of a hybrid thermochemical process, by a combination of heat and electrolysis, could meet these goals. Hydrogen produced from

  4. Achievement report for fiscal 1976 on Sunshine Program. Research and development of hydrogen production technology using high-temperature high-pressure water electrolysis; 1976 nendo koon koatsusui denkaiho ni yoru suiso seizo gijutsu no kenkyu kaihatsu seika hokokusho

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1977-03-01

    Basic data are collected for the construction of a high-temperature high-pressure membrane-assisted water electrolysis test plant of the constant load type and another of the variable load type. To collect the data, basic experiments are conducted on a small water electrolysis unit, diaphragms are fabricated and tested for performance, design calculation is performed using a computer, a test unit for testing electrolysis bath constituting materials is built for the construction of a gas/liquid separation unit. The ultimate goal of this project is to develop a high-temperature high-pressure water electrolysis test apparatus. The first part of this report is titled 'Outline' and states the objectives of this research, summarizes the achievements of fiscal 1974, 1975, and 1976, and mentions the names of officers responsible for the execution of the research and development, etc. The second part is titled 'Contents of research' and reports the details of the research conducted in fiscal 1976. The subjects taken up in the second part are 'Research on constant-load type high-temperature high-pressure (bipolar) diaphragm-assisted water electrolysis bath,' 'Research on Teflon-based diaphragms for high-temperature high-pressure water electrolysis baths,' 'Research on variable-load type high-temperature high-pressure diaphragm-assisted water electrolysis bath,' 'Research on small test plant electrolysis bath design,' etc., which are being undertaken by Showa Denko K.K. and four other corporations. (NEDO)

  5. Magnetic resonance studies of atomic hydrogen gas at low temperatures

    International Nuclear Information System (INIS)

    Hardy, W.N.; Morrow, M.; Jochemsen, R.; Statt, B.W.; Kubik, P.R.; Marsolais, R.M.; Berlinsky, A.J.; Landesman, A.

    1980-01-01

    Using a pulsed low temperature discharge in a closed cell containing H 2 and 4 He, we have been able to store a low density (approximately 10 12 atoms/cc) gas of atomic hydrogen for periods of order one hour in zero magnetic field and T=1 K. Pulsed magnetic resonance at the 1420 MHz hyperfine transition has been used to study a number of the properties of the gas, including the recombination rate H + H + 4 He→H 2 + 4 He, the hydrogen spin-exchange relaxation rates, the diffusion coefficient of H in 4 He gas and the pressure shift of the hyperfine frequency due to the 4 He buffer gas. Here we discuss the application of hyperfine frequency shifts as a probe of the H-He potential, and as a means for determining the binding energy of H on liquid helium

  6. First high energy hydrogen cluster beams

    International Nuclear Information System (INIS)

    Gaillard, M.J.; Genre, R.; Hadinger, G.; Martin, J.

    1993-03-01

    The hydrogen cluster accelerator of the Institut de Physique Nucleaire de Lyon (IPN Lyon) has been upgraded by adding a Variable Energy Post-accelerator of RFQ type (VERFQ). This operation has been performed in the frame of a collaboration between KfK Karlsruhe, IAP Frankfurt and IPN Lyon. The facility has been designed to deliver beams of mass selected Hn + clusters, n chosen between 3 and 49, in the energy range 65-100 keV/u. For the first time, hydrogen clusters have been accelerated at energies as high as 2 MeV. This facility opens new fields for experiments which will greatly benefit from a velocity range never available until now for such exotic projectiles. (author) 13 refs.; 1 fig

  7. Operational Modelling of High Temperature Electrolysis (HTE)

    International Nuclear Information System (INIS)

    Patrick Lovera; Franck Blein; Julien Vulliet

    2006-01-01

    Solid Oxide Fuel Cells (SOFC) and High Temperature Electrolysis (HTE) work on two opposite processes. The basic equations (Nernst equation, corrected by a term of over-voltage) are thus very similar, only a few signs are different. An operational model, based on measurable quantities, was finalized for HTE process, and adapted to SOFCs. The model is analytical, which requires some complementary assumptions (proportionality of over-tensions to the current density, linearization of the logarithmic term in Nernst equation). It allows determining hydrogen production by HTE using a limited number of parameters. At a given temperature, only one macroscopic parameter, related to over-voltages, is needed for adjusting the model to the experimental results (SOFC), in a wide range of hydrogen flow-rates. For a given cell, this parameter follows an Arrhenius law with a satisfactory precision. The prevision in HTE process is compared to the available experimental results. (authors)

  8. Hydrogen high pressure proportional drift detector

    International Nuclear Information System (INIS)

    Arefiev, A.; Balaev, A.

    1983-01-01

    The design and operation performances of a proportional drift detector PDD are described. High sensitivity of the applied PAD makes it possible to detect the neutron-proton elastic scattering in the energy range of recoil protons as low as 1 keV. The PDD is filled with hydrogen up to the pressure at 40 bars. High purity of the gas is maintained by a continuously operating purification system. The detector has been operating for several years in a neutron beam at the North Area of the CERN SPS

  9. The probability of heterogeneous recombination of hydrogen atoms in low-temperature hydrogen plasma

    International Nuclear Information System (INIS)

    Islyaikin, A.; Rybkin, V.; Svetsov, V.

    2000-01-01

    In the group of the optical methods, the investigations of the process of recombination of the hydrogen atoms were studied mainly by the jet procedure, based on the measurement of the dependence of the intensity of radiation of the discharge on the speed of flow of particles which makes it possible to obtain information on the processes of annihilation of active particles on the surface of the discharge device both in the zone of plasma at outside to the zone (in the post glow region). However, to realise this method, it is necessary to use higher linear speed of the flow of the particles and this creates additional technical difficulties. A similar disadvantage is not found in the calculation methods of technical application with special reference to the examination of the processes of heterogeneous recombination of the atoms in the low-temperature hydrogen plasma is the main task of this work

  10. Development of Very High Temperature Reactor Technology

    International Nuclear Information System (INIS)

    Lee, Won Jae; Noh, J. M.; Kim, Y. H.

    2009-04-01

    For an efficient production of nuclear hydrogen, the VHTR (Very High Temperature Gas-cooled Reactor) of 950 .deg. C outlet temperature and the interfacing system for the hydrogen production are required. We have developed various evaluation technologies for the performance and safety of VHTR through the accomplishment of this project. First, to evaluate the performance of VHTR, a series of analyses has been performed such as core characteristics at 950 .deg. C, applicability of cooled-vessel, intermediate loop system and high temperature structural integrity. Through the analyses of major accidents such as HPCC and LPCC and the analysis of the risk/performance-informed method, VHTR safety evaluation has been also performed. In addition, various design analysis codes have been developed for a nuclear design, system loop design, system performance analysis, air-ingress accident analysis, fission product/tritium transport analysis, graphite structure seismic analysis and hydrogen explosion analysis, and they are being verified and validated through a lot of international collaborations

  11. Hydrogen distribution in a containment with a high-velocity hydrogen-steam source

    International Nuclear Information System (INIS)

    Bloom, G.R.; Muhlestein, L.D.; Postma, A.K.; Claybrook, S.W.

    1982-09-01

    Hydrogen mixing and distribution tests are reported for a modeled high velocity hydrogen-steam release from a postulated small pipe break or release from a pressurizer relief tank rupture disk into the lower compartment of an Ice Condenser Plant. The tests, which in most cases used helium as a simulant for hydrogen, demonstrated that the lower compartment gas was well mixed for both hydrogen release conditions used. The gas concentration differences between any spatial locations were less than 3 volume percent during the hydrogen/steam release period and were reduced to less than 0.5 volume percent within 20 minutes after termination of the hydrogen source. The high velocity hydrogen/steam jet provided the dominant mixing mechanism; however, natural convection and forced air recirculation played important roles in providing a well mixed atmosphere following termination of the hydrogen source. 5 figures, 4 tables

  12. Neutron temperature measurements in a cryogenic hydrogenous moderator

    International Nuclear Information System (INIS)

    Ball, R.M.; Hoovler, G.S.; Lewis, R.H.

    1995-01-01

    Benchmarkings of neutronic calculations are most successful when there is a direct correlation between a measurement and an analytic result. In the thermal neutron energy region, the fluence rate as a function of moderator temperature and position within the moderator is an area of potential correlation. The measurement can be done by activating natural lutetium. The two isotopes of the element lutetium have widely different cross sections and permit the discrimination of flux shape and energy distributions at different reactor conditions. The 175 Lu has a 1/v dependence in the thermal energy region, and 176 Lu has a resonance structure that approximates a constant cross section in the same region. The saturation activation of the two isotopes has been measured in an insulated moderator container at the center of a thermal heterogeneous reactor designed for space nuclear propulsion. The measurements were made in a hydrogenous (polyethylene) moderator at three temperatures (83, 184, and 297 K) and five locations within the moderator. Simultaneously, the reactivity effect of the change in the moderator temperature was determined to be positive with an increase in temperature. The plot of activation shows the variation in neutron fluence rate and current with temperature and explains the positive reactivity coefficient. A neutron temperature can be inferred from a postulated Maxwell-Boltzmann distribution and compared with Monte Carlo or other calculations

  13. 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...

  14. Residual gas entering high density hydrogen plasma: rarefaction due to rapid heating

    NARCIS (Netherlands)

    N. den Harder,; D.C. Schram,; W. J. Goedheer,; de Blank, H. J.; M. C. M. van de Sanden,; van Rooij, G. J.

    2015-01-01

    The interaction of background molecular hydrogen with magnetized (0.4 T) high density (1–5 × 10 20  m −3 ) low temperature (∼3 eV) hydrogen plasma was inferred from the Fulcher band emission in the linear plasma generator Pilot-PSI. In the plasma center,

  15. Advances in high temperature chemistry

    CERN Document Server

    Eyring, Leroy

    1969-01-01

    Advances in High Temperature Chemistry, Volume 2 covers the advances in the knowledge of the high temperature behavior of materials and the complex and unfamiliar characteristics of matter at high temperature. The book discusses the dissociation energies and free energy functions of gaseous monoxides; the matrix-isolation technique applied to high temperature molecules; and the main features, the techniques for the production, detection, and diagnosis, and the applications of molecular beams in high temperatures. The text also describes the chemical research in streaming thermal plasmas, as w

  16. Divertor, thermonuclear device and method of neutralizing high temperature plasma

    International Nuclear Information System (INIS)

    Ikegami, Hideo.

    1995-01-01

    The thermonuclear device comprises a thermonuclear reactor for taking place fusion reactions to emit fusion plasmas, and a divertor made of a hydrogen occluding material, and the divertor is disposed at a position being in contact with the fusion plasmas after nuclear fusion reaction. The divertor is heated by fusion plasmas after nuclear fusion reaction, and hydrogen is released from the hydrogen occluding material as a constituent material. A gas blanket is formed by the released hydrogen to cool and neutralize the supplied high temperature nuclear fusion plasmas. This prevents the high temperature plasmas from hitting against the divertor, elimination of the divertor by melting and evaporation, and solve a problem of processing a divertor activated by neutrons. In addition, it is possible to utilize hydrogen isotopes of fuels effectively and remove unnecessary helium. Inflow of impurities from out of the system can also be prevented. (N.H.)

  17. Membrane steam reforming of natural gas for hydrogen production by utilization of medium temperature nuclear reactor

    International Nuclear Information System (INIS)

    Djati Hoesen Salimy

    2010-01-01

    The assessment of steam reforming process with membrane reactor for hydrogen production by utilizing of medium temperature nuclear reactor has been carried out. Difference with the conventional process of natural gas steam reforming that operates at high temperature (800-1000°C), the process with membrane reactor operates at lower temperature (~500°C). This condition is possible because the use of perm-selective membrane that separate product simultaneously in reactor, drive the optimum conversion at the lower temperature. Besides that, membrane reactor also acts the role of separation unit, so the plant will be more compact. From the point of nuclear heat utilization, the low temperature of process opens the chance of medium temperature nuclear reactor utilization as heat source. Couple the medium temperature nuclear reactor with the process give the advantage from the point of saving fossil fuel that give direct implication of decreasing green house gas emission. (author)

  18. Low temperature isotope effects of hydrogen diffusion in metallic glasses

    International Nuclear Information System (INIS)

    Hofmann, A.; Kronmueller, H.

    1989-01-01

    Snoek-like relaxation peaks of Hydrogen and Deuterium in amorphous Fe 80 B 20 , Fe 40 Ni 40 P 14 B 6 and Fe 91 Zr 9 are detected. At low H, D concentrations the peaks are near 200 K and show small isotope effects of the average activation energies (anti Q H ≅ 0.6 eV, anti Q D - anti Q H ≤ 10 meV). For higher H, D-contents the peaks shift to lower temperatures around to 120 K and show distinct isotope effects in the activation energies (anti Q H ≅ 0.3 eV, anti Q D - anti Q H ≅ 30 meV) and in the amplitude of the low temperature tails of the relaxation peaks. This points to isotope mass dependent deviations from the Arrhenius law due to nonthermal tunneling processes. (orig.)

  19. Low temperature hydrogen embrittlement of niobium. II. Microscopic observations

    International Nuclear Information System (INIS)

    Grossbeck, M.L.; Birnbaum, H.K.

    1977-01-01

    The detailed, microscopic processes which occur during the hydrogen embrittlement of pure Nb are examined using in situ SEM crack propagation studies, SEM fractography, electron diffraction and ion probe methods. These results show that the fracture process occurs in a stress induced NbH hydride phase which forms in front of the propagating crack. The experimental results are in good agreement with the stress induced hydride embrittlement mechanism which is discussed. The thermodynamics of precipitation of hydrides under external stress is discussed and calculations are presented for the stress effects on the α-β solvus temperatures. These are related to the embrittlement process and evidence is presented to support the calculated stress effects on the solvus temperature

  20. On the temperature dependence of H-U{sub iso} in the riding hydrogen model

    Energy Technology Data Exchange (ETDEWEB)

    Lübben, Jens; Volkmann, Christian [Institut für Anorganische Chemie, Georg-August-Universität, Tammannstrasse 4, D-37077 Göttingen (Germany); Grabowsky, Simon [School of Chemistry and Biochemistry, Stirling Highway 35, WA-6009 Crawley (Australia); Edwards, Alison [Bragg Institute, Australian Nuclear Science and Technology Organisation, Locked Bag 2001, Kirrawee DC, NSW 2232 (Australia); Morgenroth, Wolfgang [Institut für Geowissenschaften, Abteilung Kristallographie, Goethe-Universität, Altenhöferallee 1, 60438 Frankfurt am Main (Germany); Fabbiani, Francesca P. A. [GZG, Abteilung Kristallographie, Georg-August Universität, Goldschmidtstrasse 1, 37077 Göttingen (Germany); Sheldrick, George M. [Institut für Anorganische Chemie, Georg-August-Universität, Tammannstrasse 4, D-37077 Göttingen (Germany); Dittrich, Birger, E-mail: birger.dittrich@chemie.uni-hamburg.de [Institut für Anorganische und Angewandte Chemie, Martin-Luther-King-Platz 6, 20146 Hamburg (Germany); Institut für Anorganische Chemie, Georg-August-Universität, Tammannstrasse 4, D-37077 Göttingen (Germany)

    2014-07-01

    The temperature dependence of hydrogen U{sub iso} and parent U{sub eq} in the riding hydrogen model is investigated by neutron diffraction, aspherical-atom refinements and QM/MM and MO/MO cluster calculations. Fixed values of 1.2 or 1.5 appear to be underestimated, especially at temperatures below 100 K. The temperature dependence of H-U{sub iso} in N-acetyl-l-4-hydroxyproline monohydrate is investigated. Imposing a constant temperature-independent multiplier of 1.2 or 1.5 for the riding hydrogen model is found to be inaccurate, and severely underestimates H-U{sub iso} below 100 K. Neutron diffraction data at temperatures of 9, 150, 200 and 250 K provide benchmark results for this study. X-ray diffraction data to high resolution, collected at temperatures of 9, 30, 50, 75, 100, 150, 200 and 250 K (synchrotron and home source), reproduce neutron results only when evaluated by aspherical-atom refinement models, since these take into account bonding and lone-pair electron density; both invariom and Hirshfeld-atom refinement models enable a more precise determination of the magnitude of H-atom displacements than independent-atom model refinements. Experimental efforts are complemented by computing displacement parameters following the TLS+ONIOM approach. A satisfactory agreement between all approaches is found.

  1. On the temperature dependence of H-Uiso in the riding hydrogen model

    International Nuclear Information System (INIS)

    Lübben, Jens; Volkmann, Christian; Grabowsky, Simon; Edwards, Alison; Morgenroth, Wolfgang; Fabbiani, Francesca P. A.; Sheldrick, George M.; Dittrich, Birger

    2014-01-01

    The temperature dependence of hydrogen U iso and parent U eq in the riding hydrogen model is investigated by neutron diffraction, aspherical-atom refinements and QM/MM and MO/MO cluster calculations. Fixed values of 1.2 or 1.5 appear to be underestimated, especially at temperatures below 100 K. The temperature dependence of H-U iso in N-acetyl-l-4-hydroxyproline monohydrate is investigated. Imposing a constant temperature-independent multiplier of 1.2 or 1.5 for the riding hydrogen model is found to be inaccurate, and severely underestimates H-U iso below 100 K. Neutron diffraction data at temperatures of 9, 150, 200 and 250 K provide benchmark results for this study. X-ray diffraction data to high resolution, collected at temperatures of 9, 30, 50, 75, 100, 150, 200 and 250 K (synchrotron and home source), reproduce neutron results only when evaluated by aspherical-atom refinement models, since these take into account bonding and lone-pair electron density; both invariom and Hirshfeld-atom refinement models enable a more precise determination of the magnitude of H-atom displacements than independent-atom model refinements. Experimental efforts are complemented by computing displacement parameters following the TLS+ONIOM approach. A satisfactory agreement between all approaches is found

  2. High-Temperature Piezoelectric Sensing

    Directory of Open Access Journals (Sweden)

    Xiaoning Jiang

    2013-12-01

    Full Text Available Piezoelectric sensing is of increasing interest for high-temperature applications in aerospace, automotive, power plants and material processing due to its low cost, compact sensor size and simple signal conditioning, in comparison with other high-temperature sensing techniques. This paper presented an overview of high-temperature piezoelectric sensing techniques. Firstly, different types of high-temperature piezoelectric single crystals, electrode materials, and their pros and cons are discussed. Secondly, recent work on high-temperature piezoelectric sensors including accelerometer, surface acoustic wave sensor, ultrasound transducer, acoustic emission sensor, gas sensor, and pressure sensor for temperatures up to 1,250 °C were reviewed. Finally, discussions of existing challenges and future work for high-temperature piezoelectric sensing are presented.

  3. High temperature superconductor accelerator magnets

    NARCIS (Netherlands)

    van Nugteren, J.

    2016-01-01

    For future particle accelerators bending dipoles are considered with magnetic fields exceeding 20T. This can only be achieved using high temperature superconductors (HTS). These exhibit different properties from classical low temperature superconductors and still require significant research and

  4. Quantum rotation and translation of hydrogen molecules encapsulated inside C₆₀: temperature dependence of inelastic neutron scattering spectra.

    Science.gov (United States)

    Horsewill, A J; Goh, K; Rols, S; Ollivier, J; Johnson, M R; Levitt, M H; Carravetta, M; Mamone, S; Murata, Y; Chen, J Y-C; Johnson, J A; Lei, X; Turro, N J

    2013-09-13

    The quantum dynamics of a hydrogen molecule encapsulated inside the cage of a C60 fullerene molecule is investigated using inelastic neutron scattering (INS). The emphasis is on the temperature dependence of the INS spectra which were recorded using time-of-flight spectrometers. The hydrogen endofullerene system is highly quantum mechanical, exhibiting both translational and rotational quantization. The profound influence of the Pauli exclusion principle is revealed through nuclear spin isomerism. INS is shown to be exceptionally able to drive transitions between ortho-hydrogen and para-hydrogen which are spin-forbidden to photon spectroscopies. Spectra in the temperature range 1.6≤T≤280 K are presented, and examples are given which demonstrate how the temperature dependence of the INS peak amplitudes can provide an effective tool for assigning the transitions. It is also shown in a preliminary investigation how the temperature dependence may conceivably be used to probe crystal field effects and inter-fullerene interactions.

  5. Fiscal 1997 survey report. Subtask 8 (hydrogen utilization worldwide clean energy system technology) (WE-NET) (R and D of hydrogen combustion turbines/development of ultra-high temperature materials); 1997 nendo seika hokokusho. Suiso riyo kokusai clean energy system gijutsu (WE-NET) subtask 8 suiso nensho turbine kenkyu kaihatsu chokoon zairyo no kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-03-01

    For the application to hydrogen combustion turbines, the R and D were continued of heat resistant alloys, ceramic composite materials, and carbonaceous composite materials. In the development of highly efficient super alloy single crystal materials, as to the single crystal alloy (Ni-5.3Al-0.5Ti-6.0Mo-4.8W-6.0Re) and an alloy made by adding 0.15%Si to the above alloy and an alloy made by adding 2.0%Hf to the above alloy, data on high temperature tensile property and creep rupture property were obtained, and it was confirmed that Hf added alloys were excellent in strength. Relating to the development of fiber reinforced ceramics, materials for trial fabrication were fabricated by the CVI method using SiC fiber, and the evaluation test was conducted to obtain the basic data. Besides, the following were carried out: study of coating for heat resistant alloy cooled blades, development of ceramic composite materials, development of ceramic multi-structure materials and analysis of fracture behaviors under the ultra-high composite environment, development of 3D fiber reinforced composite materials, development of technology to evaluate basic properties of ultra-high temperature materials, etc. 46 refs., 217 figs., 43 tabs.

  6. Effect of microstructures on the hydrogen attack to gamma titanium aluminide at low temperature

    Energy Technology Data Exchange (ETDEWEB)

    Hamzah, E. [Faculty of Mechanical Engineering, Universiti Technologi Malaysia 81310, Johor Bahru (Malaysia)]. E-mail: esah@fkm.utm.my; Suardi, K. [Faculty of Mechanical Engineering, Universiti Technologi Malaysia 81310, Johor Bahru (Malaysia); Ourdjini, A. [Faculty of Mechanical Engineering, Universiti Technologi Malaysia 81310, Johor Bahru (Malaysia)

    2005-04-25

    Intermetallic alloys based on gamma titanium aluminide are now regarded as promising candidates for high temperature applications such as for aerospace, marine and automotive engine components, due to their high specific strength and modulus. Their oxidation resistance is good, especially at intermediate and high temperature; oxidation resistance can be obtained up to 800 deg. C. One critical area of application is in combustion engines in aerospace vehicles such as hypersonic airplanes and high-speed civil transport airplanes. This entails the use of hydrogen as a fuel component and it has been widely reported by researchers that these materials exhibit corrosion in the form of environment embrittlement in the presence of hydrogen. A fair amount of research has been carried out to investigate the influence of hydrogen in {gamma}-titanium aluminide. Some researchers reported that {alpha}{sub 2} and lamellar phases had major influence in the susceptible of hydrogen to alloys, while hydrogen is too low to penetrate the {gamma}-phases. This research focused on the effect of different microstructures of {gamma}-titanium aluminide to the diffusion coefficient of hydrogen (D) and the corrosion product after hydrogen attack. Modification of {gamma}-titanium aluminide can be achieved by heat treatment of as-cast binary samples Ti-45% Al and Ti-48% Al. All samples were then subjected to corrosion attack under cathodically charged with galvanostatic mode for 6 h. The potential variation with time was monitored from these data the values of the diffusion coefficient of hydrogen (D) to {gamma}-titanium aluminide was obtained. D was calculated based on Fick's second Law. These results were compared with that obtained from micro-Vickers hardness profiling, which was measured at cross-section area per depth from the top corroded surface. The hardness values were calculated using the error function equation. An image analyzer; X-ray diffraction (XRD); scanning electron

  7. Effect of microstructures on the hydrogen attack to gamma titanium aluminide at low temperature

    International Nuclear Information System (INIS)

    Hamzah, E.; Suardi, K.; Ourdjini, A.

    2005-01-01

    Intermetallic alloys based on gamma titanium aluminide are now regarded as promising candidates for high temperature applications such as for aerospace, marine and automotive engine components, due to their high specific strength and modulus. Their oxidation resistance is good, especially at intermediate and high temperature; oxidation resistance can be obtained up to 800 deg. C. One critical area of application is in combustion engines in aerospace vehicles such as hypersonic airplanes and high-speed civil transport airplanes. This entails the use of hydrogen as a fuel component and it has been widely reported by researchers that these materials exhibit corrosion in the form of environment embrittlement in the presence of hydrogen. A fair amount of research has been carried out to investigate the influence of hydrogen in γ-titanium aluminide. Some researchers reported that α 2 and lamellar phases had major influence in the susceptible of hydrogen to alloys, while hydrogen is too low to penetrate the γ-phases. This research focused on the effect of different microstructures of γ-titanium aluminide to the diffusion coefficient of hydrogen (D) and the corrosion product after hydrogen attack. Modification of γ-titanium aluminide can be achieved by heat treatment of as-cast binary samples Ti-45% Al and Ti-48% Al. All samples were then subjected to corrosion attack under cathodically charged with galvanostatic mode for 6 h. The potential variation with time was monitored from these data the values of the diffusion coefficient of hydrogen (D) to γ-titanium aluminide was obtained. D was calculated based on Fick's second Law. These results were compared with that obtained from micro-Vickers hardness profiling, which was measured at cross-section area per depth from the top corroded surface. The hardness values were calculated using the error function equation. An image analyzer; X-ray diffraction (XRD); scanning electron microscope (SEM) and secondary ion mass

  8. Confined high-pressure chemical deposition of hydrogenated amorphous silicon.

    Science.gov (United States)

    Baril, Neil F; He, Rongrui; Day, Todd D; Sparks, Justin R; Keshavarzi, Banafsheh; Krishnamurthi, Mahesh; Borhan, Ali; Gopalan, Venkatraman; Peacock, Anna C; Healy, Noel; Sazio, Pier J A; Badding, John V

    2012-01-11

    Hydrogenated amorphous silicon (a-Si:H) is one of the most technologically important semiconductors. The challenge in producing it from SiH(4) precursor is to overcome a significant kinetic barrier to decomposition at a low enough temperature to allow for hydrogen incorporation into a deposited film. The use of high precursor concentrations is one possible means to increase reaction rates at low enough temperatures, but in conventional reactors such an approach produces large numbers of homogeneously nucleated particles in the gas phase, rather than the desired heterogeneous deposition on a surface. We report that deposition in confined micro-/nanoreactors overcomes this difficulty, allowing for the use of silane concentrations many orders of magnitude higher than conventionally employed while still realizing well-developed films. a-Si:H micro-/nanowires can be deposited in this way in extreme aspect ratio, small-diameter optical fiber capillary templates. The semiconductor materials deposited have ~0.5 atom% hydrogen with passivated dangling bonds and good electronic properties. They should be suitable for a wide range of photonic and electronic applications such as nonlinear optical fibers and solar cells. © 2011 American Chemical Society

  9. A new type of hydrogen generator-HHEG (high-compressed hydrogen energy generator)

    International Nuclear Information System (INIS)

    Harada, H.; Tojima, K.; Takeda, M.; Nakazawa, T.

    2004-01-01

    'Full text:' We have developed a new type of hydrogen generator named HHEG (High-compressed Hydrogen Energy Generator). HHEG can produce 35 MPa high-compressed hydrogen for fuel cell vehicle without any mechanical compressor. HHEG is a kind of PEM(proton exchange membrane)electrolysis. It was well known that compressed hydrogen could be generated by water electrolysis. However, the conventional electrolysis could not generate 35 MPa or higher pressure that is required for fuel cell vehicle, because electrolysis cell stack is destroyed in such high pressure. In HHEG, the cell stack is put in high-pressure vessel and the pressure difference of oxygen and hydrogen that is generated by the cell stack is always kept at nearly zero by an automatic compensator invented by Mitsubishi Corporation. The cell stack of HHEG is not so special one, but it is not broken under such high pressure, because the automatic compensator always offsets the force acting on the cell stack. Hydrogen for fuel cell vehicle must be produce by no emission energy such as solar and atomic power. These energies are available as electricity. So, water electrolysis is the only way of producing hydrogen fuel. Hydrogen fuel is also 35 MPa high-compressed hydrogen and will become 70 MPa in near future. But conventional mechanical compressor is not useful for such high pressure hydrogen fuel, because of the short lifetime and high power consumption. Construction of hydrogen station network is indispensable in order to come into wide use of fuel cell vehicles. For such network contraction, an on-site type hydrogen generator is required. HHEG can satisfy above these requirements. So we can conclude that HHEG is the only way of realizing the hydrogen economy. (author)

  10. Fiscal 1975 Sunshine Project research report. R and D on hydrogen production technology by high-temperature high- pressure water electrolysis; 1975 nendo koon koatsusui denkaiho ni yoru suiso seizo gijutsu no kenkyu kaihatsu seika hokokusho

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1976-05-29

    This report details the research result in fiscal 1975. Part 1 'Outlines' includes the research target, the summary of fiscal 1974 research results, the summary of fiscal 1975 research results, and responsible researchers. Part 2 'Details of the research' includes the fiscal 1975 research results. Chapter 1 reports 'Study on constant-load high- temperature high-pressure (multi-electrode type) diaphragm water electrolysis tank' promoted by Mitsubishi Kakoki Kaisha. Chapter 2 reports 'Study on Teflon system diaphragm for high-temperature high-pressure water electrolysis tanks' promoted by Yuasa Battery Co. through Mitsubishi Kakoki Kaisha. Chapter 3 reports 'Study on variable-load high- temperature high-pressure diaphragm water electrolysis tank' promoted by Showa Denko K.K. Chapter 4 reports 'The first detailed design of the electrolysis tank for a small test plant' promoted by Hitachi Zosen Corp. through Showa Denko K.K. Chapter 5 reports 'Research on the applicability of water electrolysis systems to various fields' promoted by Mitsubishi Research Institute, Inc. through Showa Denko K.K. (NEDO)

  11. Fiscal 1975 Sunshine Project research report. R and D on hydrogen production technology by high-temperature high- pressure water electrolysis; 1975 nendo koon koatsusui denkaiho ni yoru suiso seizo gijutsu no kenkyu kaihatsu seika hokokusho

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1976-05-29

    This report details the research result in fiscal 1975. Part 1 'Outlines' includes the research target, the summary of fiscal 1974 research results, the summary of fiscal 1975 research results, and responsible researchers. Part 2 'Details of the research' includes the fiscal 1975 research results. Chapter 1 reports 'Study on constant-load high- temperature high-pressure (multi-electrode type) diaphragm water electrolysis tank' promoted by Mitsubishi Kakoki Kaisha. Chapter 2 reports 'Study on Teflon system diaphragm for high-temperature high-pressure water electrolysis tanks' promoted by Yuasa Battery Co. through Mitsubishi Kakoki Kaisha. Chapter 3 reports 'Study on variable-load high- temperature high-pressure diaphragm water electrolysis tank' promoted by Showa Denko K.K. Chapter 4 reports 'The first detailed design of the electrolysis tank for a small test plant' promoted by Hitachi Zosen Corp. through Showa Denko K.K. Chapter 5 reports 'Research on the applicability of water electrolysis systems to various fields' promoted by Mitsubishi Research Institute, Inc. through Showa Denko K.K. (NEDO)

  12. Selective Hydrogenation of Acrolein Over Pd Model Catalysts: Temperature and Particle-Size Effects.

    Science.gov (United States)

    O'Brien, Casey P; Dostert, Karl-Heinz; Schauermann, Swetlana; Freund, Hans-Joachim

    2016-10-24

    The selectivity in the hydrogenation of acrolein over Fe 3 O 4 -supported Pd nanoparticles has been investigated as a function of nanoparticle size in the 220-270 K temperature range. While Pd(111) shows nearly 100 % selectivity towards the desired hydrogenation of the C=O bond to produce propenol, Pd nanoparticles were found to be much less selective towards this product. In situ detection of surface species by using IR-reflection absorption spectroscopy shows that the selectivity towards propenol critically depends on the formation of an oxopropyl spectator species. While an overlayer of oxopropyl species is effectively formed on Pd(111) turning the surface highly selective for propenol formation, this process is strongly hindered on Pd nanoparticles by acrolein decomposition resulting in CO formation. We show that the extent of acrolein decomposition can be tuned by varying the particle size and the reaction temperature. As a result, significant production of propenol is observed over 12 nm Pd nanoparticles at 250 K, while smaller (4 and 7 nm) nanoparticles did not produce propenol at any of the temperatures investigated. The possible origin of particle-size dependence of propenol formation is discussed. This work demonstrates that the selectivity in the hydrogenation of acrolein is controlled by the relative rates of acrolein partial hydrogenation to oxopropyl surface species and of acrolein decomposition, which has significant implications for rational catalyst design. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Influence of temperature, hydrogen and boric acid concentration on IGSCC susceptibility of unsensitized 316 stainless steel

    Energy Technology Data Exchange (ETDEWEB)

    Arioka, Koji [Inst. of Nuclear Safety System Inc., Mihama, Fukui (Japan)

    2002-09-01

    IGSCC susceptibility of unsensitized 316SS under PWR primary water was studied as a function of solution temperature, dissolved hydrogen, and boric acid concentration by SSRT test using specimens with cold deformed hump. IGSCC growth rate was dependent on temperature and the obtained activation energy was 21.6K cal/mol. Regarding the influence of dissolved hydrogen, there was a simple monotonic increase in crack growth rate with the increasing hydrogen concentration within the PWR primary water chemistry specifications. Also, there was a remarkable difference in IGSCC susceptibility with regard to the effect to boric acid concentration. Within the tested concentration, the IGSCC susceptibility under high concentrated boric acid solution (2300ppm B) was inhibited in comparison with that under 500ppm B. These temperature and dissolved hydrogen dependencies of IGSCC susceptibility were similar to the literature on published data on irradiated 316SS. Although further study is required to clarify the mechanism, however the similarity of the dependencies suggests that the rate-limited IGSCC process of un-irradiated 316SS is related to that of IASCC. (author)

  14. Premixer Design for High Hydrogen Fuels

    Energy Technology Data Exchange (ETDEWEB)

    Benjamin P. Lacy; Keith R. McManus; Balachandar Varatharajan; Biswadip Shome

    2005-12-16

    This 21-month project translated DLN technology to the unique properties of high hydrogen content IGCC fuels, and yielded designs in preparation for a future testing and validation phase. Fundamental flame characterization, mixing, and flame property measurement experiments were conducted to tailor computational design tools and criteria to create a framework for predicting nozzle operability (e.g., flame stabilization, emissions, resistance to flashback/flame-holding and auto-ignition). This framework was then used to establish, rank, and evaluate potential solutions to the operability challenges of IGCC combustion. The leading contenders were studied and developed with the most promising concepts evaluated via computational fluid dynamics (CFD) modeling and using the design rules generated by the fundamental experiments, as well as using GE's combustion design tools and practices. Finally, the project scoped the necessary steps required to carry the design through mechanical and durability review, testing, and validation, towards full demonstration of this revolutionary technology. This project was carried out in three linked tasks with the following results. (1) Develop conceptual designs of premixer and down-select the promising options. This task defined the ''gap'' between existing design capabilities and the targeted range of IGCC fuel compositions and evaluated the current capability of DLN pre-mixer designs when operated at similar conditions. Two concepts (1) swirl based and (2) multiple point lean direct injection based premixers were selected via a QFD from 13 potential design concepts. (2) Carry out CFD on chosen options (1 or 2) to evaluate operability risks. This task developed the leading options down-selected in Task 1. Both a GE15 swozzle based premixer and a lean direct injection concept were examined by performing a detailed CFD study wherein the aerodynamics of the design, together with the chemical kinetics of the

  15. High Temperature Superconductor Resonator Detectors

    Data.gov (United States)

    National Aeronautics and Space Administration — High Temperature Superconductor (HTS) infrared detectors were studied for years but never matured sufficiently for infusion into instruments. Several recent...

  16. High Temperature Superconductor Machine Prototype

    DEFF Research Database (Denmark)

    Mijatovic, Nenad; Jensen, Bogi Bech; Træholt, Chresten

    2011-01-01

    A versatile testing platform for a High Temperature Superconductor (HTS) machine has been constructed. The stationary HTS field winding can carry up to 10 coils and it is operated at a temperature of 77K. The rotating armature is at room temperature. Test results and performance for the HTS field...

  17. High stability of palladium/kieselguhr composites during absorption/desorption cycling for hydrogen isotope separation

    Energy Technology Data Exchange (ETDEWEB)

    Lei, Yang, E-mail: lei.y@outlook.com; Liu, Xiaopeng; Li, Shuo; Jiang, Lijun; Zhang, Chao; Li, Shuai; He, Di; Wang, Shumao

    2016-12-15

    Highlights: • Pd/K composites with as high as 57 wt.% of Pd have been successfully prepared. • Palladium particles can be effectively packed into the pores of kieselguhr substrates. • Variation of heat-treatment temperatures hardly affect hydrogen absorption capacity and hydrogen saturation time of the Pd/K. • Anti-pulverization property of Pd/K can be improved by packing palladium into the kieselguhr internal pores and heating at 1300 °C. - Abstract: Palladium/kieselguhr (Pd/K) composites with 57 wt.% of Pd were prepared by an improved dipping and thermal decomposition method and heated at elevated temperature to reduce breakdown during hydrogenation-dehydrogenation cycles. The hydrogen absorption kinetic properties of the samples heated at different temperatures were tested under the condition of 20 °C with 100 kPa hydrogen pressure. The 1300 °C heated Pd/K composites were repeated up to 4010 absorption and desorption cycles at temperature ranges between −40 °C and 200 °C. The results show that the phase structure, hydrogen absorption capacity and hydrogen saturation time of the Pd/K were not affected by the change of heat-treated temperatures. And after heat treatment at 1300 °C, the Pd/K particles were strengthened and fraction of larger than 80 mesh were as high as 93.4%.

  18. Low Cost, High Efficiency, High Pressure Hydrogen Storage

    Energy Technology Data Exchange (ETDEWEB)

    Mark Leavitt

    2010-03-31

    A technical and design evaluation was carried out to meet DOE hydrogen fuel targets for 2010. These targets consisted of a system gravimetric capacity of 2.0 kWh/kg, a system volumetric capacity of 1.5 kWh/L and a system cost of $4/kWh. In compressed hydrogen storage systems, the vast majority of the weight and volume is associated with the hydrogen storage tank. In order to meet gravimetric targets for compressed hydrogen tanks, 10,000 psi carbon resin composites were used to provide the high strength required as well as low weight. For the 10,000 psi tanks, carbon fiber is the largest portion of their cost. Quantum Technologies is a tier one hydrogen system supplier for automotive companies around the world. Over the course of the program Quantum focused on development of technology to allow the compressed hydrogen storage tank to meet DOE goals. At the start of the program in 2004 Quantum was supplying systems with a specific energy of 1.1-1.6 kWh/kg, a volumetric capacity of 1.3 kWh/L and a cost of $73/kWh. Based on the inequities between DOE targets and Quantum’s then current capabilities, focus was placed first on cost reduction and second on weight reduction. Both of these were to be accomplished without reduction of the fuel system’s performance or reliability. Three distinct areas were investigated; optimization of composite structures, development of “smart tanks” that could monitor health of tank thus allowing for lower design safety factor, and the development of “Cool Fuel” technology to allow higher density gas to be stored, thus allowing smaller/lower pressure tanks that would hold the required fuel supply. The second phase of the project deals with three additional distinct tasks focusing on composite structure optimization, liner optimization, and metal.

  19. High pressure direct synthesis of adipic acid from cyclohexene and hydrogen peroxide via capillary microreactors

    NARCIS (Netherlands)

    Shang, M.; Noël, T.; Su, Y.; Hessel, V.

    2016-01-01

    The direct synthesis of adipic acid from hydrogen peroxide and cyclohexene was investigated in capillary microreactors at high temperature (up to 115°C ) and pressure (up to 70 bar). High temperature was already applied in micro-flow packed-bed reactors for the direct adipic acid synthesis. In our

  20. Selective gettering of hydrogen in high pressure metal iodide lamps

    International Nuclear Information System (INIS)

    Kuus, G.

    1976-01-01

    One of the main problems in the manufacture of high pressure gas discharge lamps is the elimination of gaseous impurities from their arc tubes. Long degassing processes of all the lamp components are necessary in order to produce lamps with a low ignition voltage and good maintenance of the radiation properties. The investigation described deals with a selective getter place in the arc tube which can replace the long degassing process. The getter consists of a piece of yttrium encapsulated in thin tantalum foil. By this way it is possible to use the gettering action of tantalum and yttrium without having reaction between the metal iodide of the arc tube and yttrium. Yttrium is used because this metal can adsorb a large quantity of hydrogen even at a temperature of 1000 0 C. Hydrogen forms the main gaseous impurity in the high pressure metal iodide lamp. For this reason the adsorption properties like adsorption rate and capacity of the tantalum--yttrium getter for hydrogen are examined, and the results obtained from lamp experiments are given

  1. Efficient preparation of highly hydrogenated graphene and its application as a high-performance anode material for lithium ion batteries

    Science.gov (United States)

    Chen, Wufeng; Zhu, Zhiye; Li, Sirong; Chen, Chunhua; Yan, Lifeng

    2012-03-01

    A novel method has been developed to prepare hydrogenated graphene (HG) via a direct synchronized reduction and hydrogenation of graphene oxide (GO) in an aqueous suspension under 60Co gamma ray irradiation at room temperature. GO can be reduced by the aqueous electrons (eaq-) while the hydrogenation takes place due to the hydrogen radicals formed in situ under irradiation. The maximum hydrogen content of the as-prepared highly hydrogenated graphene (HHG) is found to be 5.27 wt% with H/C = 0.76. The yield of the target product is on the gram scale. The as-prepared HHG also shows high performance as an anode material for lithium ion batteries.

  2. Investigation of hydrogen bubbles behavior in tungsten by high-flux hydrogen implantation

    Science.gov (United States)

    Zhao, Jiangtao; Meng, Xuan; Guan, Xingcai; Wang, Qiang; Fang, Kaihong; Xu, Xiaohui; Lu, Yongkai; Gao, Jun; Liu, Zhenlin; Wang, Tieshan

    2018-05-01

    Hydrogen isotopes retention and bubbles formation are critical issues for tungsten as plasma-facing material in future fusion reactors. In this work, the formation and growing up behavior of hydrogen bubbles in tungsten were investigated experimentally. The planar TEM samples were implanted by 6.0keV hydrogens to a fluence of 3.38 ×1018 H ṡ cm-2 at room temperature, and well-defined hydrogen bubbles were observed by TEM. It was demonstrated that hydrogen bubbles formed when exposed to a fluence of 1.5 ×1018 H ṡ cm-2 , and the hydrogen bubbles grew up with the implantation fluence. In addition, the bubbles' size appeared larger with higher beam flux until saturated at a certain flux, even though the total fluence was kept the same. Finally, in order to understand the thermal annealing effect on the bubbles behavior, hydrogen-implanted samples were annealed at 400, 600, 800, and 1000 °C for 3 h. It was obvious that hydrogen bubbles' morphology changed at temperatures higher than 800 °C.

  3. Hydrogen Temperature-Programmed Desorption (H2 TPD) of Supported Platinum Catalysts.

    NARCIS (Netherlands)

    Koningsberger, D.C.; Miller, J.T.; Meyers, B.L.; Modica, F.S.; Lane, G.S.; Vaarkamp, M.

    1993-01-01

    Hydrogen temperature-programmed desorption (TPD) of supported platinum catalysts, Pt/KLTL, Pt/H-LTL, Pt/K-MAZ, Pt/H-MAZ, Pt/-Al2O3, and Pt/SiO2, was performed after hydrogen reduction at 300, 450, or 650°C. For all catalysts, reversible desorption of chemisorbed hydrogen occurred at approximately

  4. Morphology, Microstructure, and Hydrogen Content of Carbon Nanostructures Obtained by PECVD at Various Temperatures

    Directory of Open Access Journals (Sweden)

    M. Acosta Gentoiu

    2017-01-01

    Full Text Available Carbon nanostructures were obtained by acetylene injection into an argon plasma jet in the presence of hydrogen. The samples were synthesized in similar conditions, except that the substrate deposition temperatures TD were varied, ranging from 473 to 973 K. A strong dependence of morphology, structure, and graphitization upon TD was found. We obtained vertical aligned carbon nanotubes (VA-CNTs at low temperatures as 473 K, amorphous carbon nanoparticles (CNPs at temperatures from about 573 to 673 K, and carbon nanowalls (CNWs at high temperatures from 773 to 973 K. Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, elastic recoil detection analysis, X-ray photoelectron spectroscopy, and Raman spectroscopy were used to substantiate the differences in these material types. It is known that hydrogen concentration modifies strongly the properties of the materials. Different concentrations of hydrogen-bonded carbon could be identified in amorphous CNP, VA-CNT, and CNW. Also, the H : C ratios along depth were determined for the obtained materials.

  5. Atomic and molecular hydrogen gas temperatures in a low-pressure helicon plasma

    Science.gov (United States)

    Samuell, Cameron M.; Corr, Cormac S.

    2015-08-01

    Neutral gas temperatures in hydrogen plasmas are important for experimental and modelling efforts in fusion technology, plasma processing, and surface modification applications. To provide values relevant to these application areas, neutral gas temperatures were measured in a low pressure (radiofrequency helicon discharge using spectroscopic techniques. The atomic and molecular species were not found to be in thermal equilibrium with the atomic temperature being mostly larger then the molecular temperature. In low power operation (measurements near a graphite target demonstrated localised cooling near the sample surface. The temporal evolution of the molecular gas temperature during a high power 1.1 ms plasma pulse was also investigated and found to vary considerably as a function of pressure.

  6. The lithium-lithium hydride process for the production of hydrogen: comparison of two concepts for 950 and 1300 deg C HTR helium outlet temperature

    International Nuclear Information System (INIS)

    Oertel, M.; Weirich, W.; Kuegler, B.; Luecke, L.; Pietsch, M.; Winkelmann, U.

    1987-01-01

    The lithium-lithium hydride process serves to generate hydrogen from water efficiently, using the high temperature heat of a nuclear reactor. Thermodynamic analyses show that hydrogen can be produced with an overall thermal efficiency of 48% at conventional HTR outlet temperatures of 950 0 C. Assuming helium heat of 1300 0 C, 56% overall thermal efficiency can be achieved. (author)

  7. Synergistic effect of helium and hydrogen for bubble swelling in reduced-activation ferritic/martensitic steel under sequential helium and hydrogen irradiation at different temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Wenhui [Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education, Hubei Nuclear Solid Physics Key Laboratory and School of Physics and Technology, Wuhan University, Wuhan 430072 (China); Guo, Liping, E-mail: guolp@whu.edu.cn [Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education, Hubei Nuclear Solid Physics Key Laboratory and School of Physics and Technology, Wuhan University, Wuhan 430072 (China); Chen, Jihong; Luo, Fengfeng; Li, Tiecheng [Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education, Hubei Nuclear Solid Physics Key Laboratory and School of Physics and Technology, Wuhan University, Wuhan 430072 (China); Ren, Yaoyao [Center for Electron Microscopy, Wuhan University, Wuhan 430072 (China); Suo, Jinping; Yang, Feng [State Key Laboratory of Mould Technology, Institute of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074 (China)

    2014-04-15

    Highlights: • Helium/hydrogen synergistic effect can increase irradiation swelling of RAFM steel. • Hydrogen can be trapped to the outer surface of helium bubbles. • Too large a helium bubble can become movable. • Point defects would become mobile and annihilate at dislocations at high temperature. • The peak swelling temperature for RAFM steel is 450 °C. - Abstract: In order to investigate the synergistic effect of helium and hydrogen on swelling in reduced-activation ferritic/martensitic (RAFM) steel, specimens were separately irradiated by single He{sup +} beam and sequential He{sup +} and H{sup +} beams at different temperatures from 250 to 650 °C. Transmission electron microscope observation showed that implantation of hydrogen into the specimens pre-irradiated by helium can result in obvious enhancement of bubble size and swelling rate which can be regarded as a consequence of hydrogen being trapped by helium bubbles. But when temperature increased, Ostwald ripening mechanism would become dominant, besides, too large a bubble could become mobile and swallow many tiny bubbles on their way moving, reducing bubble number density. And these effects were most remarkable at 450 °C which was the peak bubble swelling temperature for RAMF steel. When temperature was high enough, say above 450, point defects would become mobile and annihilate at dislocations or surface. As a consequence, helium could no longer effectively diffuse and clustering in materials and bubble formation was suppressed. When temperature was above 500, helium bubbles would become unstable and decompose or migrate out of surface. Finally no bubble was observed at 650 °C.

  8. Synergistic effect of helium and hydrogen for bubble swelling in reduced-activation ferritic/martensitic steel under sequential helium and hydrogen irradiation at different temperatures

    International Nuclear Information System (INIS)

    Hu, Wenhui; Guo, Liping; Chen, Jihong; Luo, Fengfeng; Li, Tiecheng; Ren, Yaoyao; Suo, Jinping; Yang, Feng

    2014-01-01

    Highlights: • Helium/hydrogen synergistic effect can increase irradiation swelling of RAFM steel. • Hydrogen can be trapped to the outer surface of helium bubbles. • Too large a helium bubble can become movable. • Point defects would become mobile and annihilate at dislocations at high temperature. • The peak swelling temperature for RAFM steel is 450 °C. - Abstract: In order to investigate the synergistic effect of helium and hydrogen on swelling in reduced-activation ferritic/martensitic (RAFM) steel, specimens were separately irradiated by single He + beam and sequential He + and H + beams at different temperatures from 250 to 650 °C. Transmission electron microscope observation showed that implantation of hydrogen into the specimens pre-irradiated by helium can result in obvious enhancement of bubble size and swelling rate which can be regarded as a consequence of hydrogen being trapped by helium bubbles. But when temperature increased, Ostwald ripening mechanism would become dominant, besides, too large a bubble could become mobile and swallow many tiny bubbles on their way moving, reducing bubble number density. And these effects were most remarkable at 450 °C which was the peak bubble swelling temperature for RAMF steel. When temperature was high enough, say above 450, point defects would become mobile and annihilate at dislocations or surface. As a consequence, helium could no longer effectively diffuse and clustering in materials and bubble formation was suppressed. When temperature was above 500, helium bubbles would become unstable and decompose or migrate out of surface. Finally no bubble was observed at 650 °C

  9. Evaluation of the security of a hydrogen producing plant by means of the S I cycle coupled to a nuclear reactor of high temperature; Evaluacion de la seguridad de una planta productora de hidrogeno mediante el ciclo SI acoplada a un reactor nuclear de alta temperatura

    Energy Technology Data Exchange (ETDEWEB)

    Ruiz S, T.; Francois, J. L.; Nelson, P. F. [UNAM, Facultad de Ingenieria, Departamento de Sistemas Energeticos, Paseo Cuauhnahuac No. 8532, Col. Progreso, 62550 Jiutepec, Morelos (Mexico); Cruz G, M. J., E-mail: truizsmx@yahoo.com.mx [UNAM, Facultad de Quimica, Ciudad Universitaria, 04510 Mexico D. F. (MX)

    2011-11-15

    At the present one of the processes that demonstrates, theoretically, to be one of the most efficient for the hydrogen production is the thermal-chemistry cycle Sulfur-Iodine. One way of obtaining the temperature ranges required by the process is through the helium coming from a very high temperature reactor. The coupling of the chemical plant with the nuclear plant presents aspects of security that should be analyzed; among them the analysis of the danger of the process materials is, with the purpose of implementing security measures to protect the facilities and equipment s, the environment and the population. These measures can be: emergency answer plans of the stations, definition of the minimum distance required among facilities, determination of the exclusion area, etc. In this study simulations were made with the computer code Phast in order to knowing the possible affectation areas due to the liberation of a great quantity of energy due to a helium leak to very high temperature, of toxic materials or by a possible hydrogen combustion. The results for the liberations of sulfuric acid, hydrogen, iodine, helium and sulfur dioxide are shown, specially. The operation conditions were taken of a combination of the preliminary design proposed by General Atomics and the optimized conditions by the Korea Advanced Institute of Science and Technology, considering a production of 1 kg-mol/s of hydrogen. The iodine was the material that presented a major affectation area. (Author)

  10. Advanced High Temperature Structural Seals

    Science.gov (United States)

    Newquist, Charles W.; Verzemnieks, Juris; Keller, Peter C.; Rorabaugh, Michael; Shorey, Mark

    2002-10-01

    This program addresses the development of high temperature structural seals for control surfaces for a new generation of small reusable launch vehicles. Successful development will contribute significantly to the mission goal of reducing launch cost for small, 200 to 300 pound payloads. Development of high temperature seals is mission enabling. For instance, ineffective control surface seals can result in high temperature (3100 F) flows in the elevon area exceeding structural material limits. Longer sealing life will allow use for many missions before replacement, contributing to the reduction of hardware, operation and launch costs.

  11. HIGH TEMPERATURE POLYMER FUEL CELLS

    DEFF Research Database (Denmark)

    Jensen, Jens Oluf; Qingfeng, Li; He, Ronghuan

    2003-01-01

    This paper will report recent results from our group on polymer fuel cells (PEMFC) based on the temperature resistant polymer polybenzimidazole (PBI), which allow working temperatures up to 200°C. The membrane has a water drag number near zero and need no water management at all. The high working...

  12. Influence of hydrogen and temperature on the mechanical behaviour in an austenitic stainless steel

    International Nuclear Information System (INIS)

    Lamani, Emil; Jouinot, Patrice

    2003-01-01

    The mechanical behaviour of an austenitic stainless steel has been studied in this work, by means of two techniques: disk pressure embrittlement test (French standard NF E 29-723) and special biaxial tensile test. Specimens for both techniques are embedded disks, loaded by a continuously increasing gas pressure until rupture. Tests have been performed at various temperatures, between 18 o C and 655 o C, with loading speeds from 0.06 to 7 MPa/min. Their main results have been recorded as relationships between gas pressure and specimen deflection until its burst or cracking. Other observations (fracture, microstructure, etc.) are performed to assess the structural evolution with the temperature. The influence of hydrogen is evaluated by the comparison of the rupture parameters of specimens tested similarly under helium and hydrogen. The embrittlement index, E.I is determined as the ratio of the rupture pressures under helium and hydrogen taking into account also the effects of the loading speed and the gas purity. It has been noticed that the mechanical behaviour of the steel is strongly influenced by the apparition of a second phase in the austenitic structure: the deformation induced martensite, α, which presence is identified by microscopic observations and X-ray diffraction. At room temperature, the steel presents a relatively high sensitivity to the hydrogen embrittlement (2.20 ≤ E.I ≤ 2.40), while, with the temperature increasing, together with the reduction of the martensitic transformation, it was observed a rapid diminution of this sensitivity. Obtained results allow to define the performance of this steel for thin walls applications, as it is the case of expansions bellows in the chemical industry. (Original)

  13. The Potential for Low-Temperature Abiotic Hydrogen Generation and a Hydrogen-Driven Deep Biosphere

    Science.gov (United States)

    Huang, Shanshan; Thorseth, Ingunn H.

    2011-01-01

    Abstract The release and oxidation of ferrous iron during aqueous alteration of the mineral olivine is known to reduce aqueous solutions to such extent that molecular hydrogen, H2, forms. H2 is an efficient energy carrier and is considered basal to the deep subsurface biosphere. Knowledge of the potential for H2 generation is therefore vital to understanding the deep biosphere on Earth and on extraterrestrial bodies. Here, we provide a review of factors that may reduce the potential for H2 generation with a focus on systems in the core temperature region for thermophilic to hyperthermophilic microbial life. We show that aqueous sulfate may inhibit the formation of H2, whereas redox-sensitive compounds of carbon and nitrogen are unlikely to have significant effect at low temperatures. In addition, we suggest that the rate of H2 generation is proportional to the dissolution rate of olivine and, hence, limited by factors such as reactive surface areas and the access of water to fresh surfaces. We furthermore suggest that the availability of water and pore/fracture space are the most important factors that limit the generation of H2. Our study implies that, because of large heat flows, abundant olivine-bearing rocks, large thermodynamic gradients, and reduced atmospheres, young Earth and Mars probably offered abundant systems where microbial life could possibly have emerged. Key Words: Serpentinization—Olivine—Hydrogen—Deep biosphere—Water—Mars. Astrobiology 11, 711–724. PMID:21923409

  14. Effect of the annealing temperature for the hydrogen Q-degradation on superconducting cavities

    International Nuclear Information System (INIS)

    Ota, Tomoko; Sukenobu, Satoru; Tanabe, Yoshio; Onishi, Yoshimichi; Noguchi, Shuichi; Ono, Masaaki; Saito, Kenji; Shishido, Toshio; Yamazaki, Yoshishige

    1997-01-01

    Hydrogen Q-degradation was studied in niobium superconducting cavities prepared by barrel polishing, and electropolishing without annealing, though a fast cooling down of cavities. Cavity performance with various annealing temperature were tested using a 1.3GHz single-cell cavity to compare the effects of annealing temperature for hydrogen Q-degradation. (author)

  15. HYFIRE: fusion-high temperature electrolysis system

    International Nuclear Information System (INIS)

    Fillo, J.A.; Powell, J.R.; Steinberg, M.; Benenati, R.; Dang, V.D.; Horn, F.; Isaacs, H.; Lazareth, O.; Makowitz, H.; Usher, J.

    1980-01-01

    The Brookhaven National Laboratory (BNL) is carrying out a comprehensive conceptual design study called HYFIRE of a commercial fusion Tokamak reactor, high-temperature electrolysis system. The study is placing particular emphasis on the adaptability of the STARFIRE power reactor to a synfuel application. The HYFIRE blanket must perform three functions: (a) provide high-temperature (approx. 1400 0 C) process steam at moderate pressures (in the range of 10 to 30 atm) to the high-temperature electrolysis (HTE) units; (b) provide high-temperature (approx. 700 to 800 0 C) heat to a thermal power cycle for generation of electricity to the HTE units; and (c) breed enough tritium to sustain the D-T fuel cycle. In addition to thermal energy for the decomposition of steam into its constitutents, H 2 and O 2 , electrical input is required. Power cycle efficiencies of approx. 40% require He cooling for steam superheat. Fourteen hundred degree steam coupled with 40% power cycle efficiency results in a process efficiency (conversion of fusion energy to hydrogen chemical energy) of 50%

  16. High Temperature Materials Laboratory (HTML)

    Data.gov (United States)

    Federal Laboratory Consortium — The six user centers in the High Temperature Materials Laboratory (HTML), a DOE User Facility, are dedicated to solving materials problems that limit the efficiency...

  17. System efficiency for two-step metal oxide solar thermochemical hydrogen production – Part 2: Impact of gas heat recuperation and separation temperatures

    KAUST Repository

    Ehrhart, Brian D.; Muhich, Christopher L.; Al-Shankiti, Ibraheam; Weimer, Alan W.

    2016-01-01

    . The hydrogen and water separation temperature was also varied and the effect on STH efficiency quantified. This study shows that gas heat recuperation is critical for high efficiency cycles, especially at conditions that require high steam and inert gas

  18. Temperature oscillations in methanol partial oxidation reactor for the production of hydrogen

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jinsu; Byeon, Jeonguk; Seo, Il Gyu; Lee, Hyun Chan; Kim, Dong Hyun; Lee, Jietae [Kyungpook National University, Daegu (Korea, Republic of)

    2013-04-15

    Methanol partial oxidation (POX) is a well-known reforming reaction for the production of hydrogen from methanol. Since POX is relatively fast and highly exothermic, this reforming method will be efficient for the fast start-up and load-following operation. However, POX generates hot spots around catalyst and even oscillations in the reactor temperature. These should be relieved for longer operations of the reactor without catalyst degradations. For this, temperature oscillations in a POX reactor are investigated experimentally. Various patterns of temperature oscillations according to feed flow rates of reactants and reactor temperatures are obtained. The bifurcation phenomena from regular oscillations to chaotic oscillations are found as the methanol flow rate increases. These experimental results can be used for theoretical analyses of oscillations and for designing safe reforming reactors.

  19. Temperature oscillations in methanol partial oxidation reactor for the production of hydrogen

    International Nuclear Information System (INIS)

    Kim, Jinsu; Byeon, Jeonguk; Seo, Il Gyu; Lee, Hyun Chan; Kim, Dong Hyun; Lee, Jietae

    2013-01-01

    Methanol partial oxidation (POX) is a well-known reforming reaction for the production of hydrogen from methanol. Since POX is relatively fast and highly exothermic, this reforming method will be efficient for the fast start-up and load-following operation. However, POX generates hot spots around catalyst and even oscillations in the reactor temperature. These should be relieved for longer operations of the reactor without catalyst degradations. For this, temperature oscillations in a POX reactor are investigated experimentally. Various patterns of temperature oscillations according to feed flow rates of reactants and reactor temperatures are obtained. The bifurcation phenomena from regular oscillations to chaotic oscillations are found as the methanol flow rate increases. These experimental results can be used for theoretical analyses of oscillations and for designing safe reforming reactors

  20. High temperature divertor plasma operation

    International Nuclear Information System (INIS)

    Ohyabu, Nobuyoshi.

    1991-02-01

    High temperature divertor plasma operation has been proposed, which is expected to enhance the core energy confinement and eliminates the heat removal problem. In this approach, the heat flux is guided through divertor channel to a remote area with a large target surface, resulting in low heat load on the target plate. This allows pumping of the particles escaping from the core and hence maintaining of the high divertor temperature, which is comparable to the core temperature. The energy confinement is then determined by the diffusion coefficient of the core plasma, which has been observed to be much lower than the thermal diffusivity. (author)

  1. Hydrogen detector

    International Nuclear Information System (INIS)

    Kumagaya, Hiromichi; Yoshida, Kazuo; Sanada, Kazuo; Chigira, Sadao.

    1994-01-01

    The present invention concerns a hydrogen detector for detecting water-sodium reaction. The hydrogen detector comprises a sensor portion having coiled optical fibers and detects hydrogen on the basis of the increase of light transmission loss upon hydrogen absorption. In the hydrogen detector, optical fibers are wound around and welded to the outer circumference of a quartz rod, as well as the thickness of the clad layer of the optical fiber is reduced by etching. With such procedures, size of the hydrogen detecting sensor portion can be decreased easily. Further, since it can be used at high temperature, diffusion rate is improved to shorten the detection time. (N.H.)

  2. High temperature high vacuum creep testing facilities

    International Nuclear Information System (INIS)

    Matta, M.K.

    1985-01-01

    Creep is the term used to describe time-dependent plastic flow of metals under conditions of constant load or stress at constant high temperature. Creep has an important considerations for materials operating under stresses at high temperatures for long time such as cladding materials, pressure vessels, steam turbines, boilers,...etc. These two creep machines measures the creep of materials and alloys at high temperature under high vacuum at constant stress. By the two chart recorders attached to the system one could register time and temperature versus strain during the test . This report consists of three chapters, chapter I is the introduction, chapter II is the technical description of the creep machines while chapter III discuss some experimental data on the creep behaviour. Of helium implanted stainless steel. 13 fig., 3 tab

  3. A light hydrocarbon fuel processor producing high-purity hydrogen

    Science.gov (United States)

    Löffler, Daniel G.; Taylor, Kyle; Mason, Dylan

    This paper discusses the design process and presents performance data for a dual fuel (natural gas and LPG) fuel processor for PEM fuel cells delivering between 2 and 8 kW electric power in stationary applications. The fuel processor resulted from a series of design compromises made to address different design constraints. First, the product quality was selected; then, the unit operations needed to achieve that product quality were chosen from the pool of available technologies. Next, the specific equipment needed for each unit operation was selected. Finally, the unit operations were thermally integrated to achieve high thermal efficiency. Early in the design process, it was decided that the fuel processor would deliver high-purity hydrogen. Hydrogen can be separated from other gases by pressure-driven processes based on either selective adsorption or permeation. The pressure requirement made steam reforming (SR) the preferred reforming technology because it does not require compression of combustion air; therefore, steam reforming is more efficient in a high-pressure fuel processor than alternative technologies like autothermal reforming (ATR) or partial oxidation (POX), where the combustion occurs at the pressure of the process stream. A low-temperature pre-reformer reactor is needed upstream of a steam reformer to suppress coke formation; yet, low temperatures facilitate the formation of metal sulfides that deactivate the catalyst. For this reason, a desulfurization unit is needed upstream of the pre-reformer. Hydrogen separation was implemented using a palladium alloy membrane. Packed beds were chosen for the pre-reformer and reformer reactors primarily because of their low cost, relatively simple operation and low maintenance. Commercial, off-the-shelf balance of plant (BOP) components (pumps, valves, and heat exchangers) were used to integrate the unit operations. The fuel processor delivers up to 100 slm hydrogen >99.9% pure with <1 ppm CO, <3 ppm CO 2. The

  4. Highly efficient hydrogen storage system based on ammonium bicarbonate/formate redox equilibrium over palladium nanocatalysts.

    Science.gov (United States)

    Su, Ji; Yang, Lisha; Lu, Mi; Lin, Hongfei

    2015-03-01

    A highly efficient, reversible hydrogen storage-evolution process has been developed based on the ammonium bicarbonate/formate redox equilibrium over the same carbon-supported palladium nanocatalyst. This heterogeneously catalyzed hydrogen storage system is comparable to the counterpart homogeneous systems and has shown fast reaction kinetics of both the hydrogenation of ammonium bicarbonate and the dehydrogenation of ammonium formate under mild operating conditions. By adjusting temperature and pressure, the extent of hydrogen storage and evolution can be well controlled in the same catalytic system. Moreover, the hydrogen storage system based on aqueous-phase ammonium formate is advantageous owing to its high volumetric energy density. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Hydrogen assisted catalytic biomass pyrolysis. Effect of temperature and pressure

    DEFF Research Database (Denmark)

    Stummann, M.Z.; Høj, M.; Schandel, C. B.

    2018-01-01

    fraction of 17 and 22% daf, corresponding to an energy recovery of between 40 and 53% in the organic product. The yield of the non-condensable gases varied between a mass fraction of 24 and 32% daf and the char yield varied between 9.6 and 18% daf. The condensed organics contained a mass fraction of 42....... The effect of varying the temperature (365–511 °C) and hydrogen pressure (1.6–3.6 MPa) on the product yield and organic composition was studied. The mass balance closed by a mass fraction between 90 and 101% dry ash free basis (daf). The yield of the combined condensed organics and C4+ varied between a mass......–75% aromatics, based on GC × GC-FID chromatographic peak area, and the remainder was primarily naphthenes with minor amounts of paraffins. The condensed organics were essentially oxygen free (mass fraction below 0.001%) when both reactors were used. Bypassing the HDO reactor increased the oxygen concentration...

  6. High-temperature bulk acoustic wave sensors

    International Nuclear Information System (INIS)

    Fritze, Holger

    2011-01-01

    Butterworth–van Dyke equivalent circuit extended by a finite bulk resistance. Assignments of the lumped elements to the physical properties are given. Finally, an application example demonstrates the capabilities of high-temperature stable piezoelectric resonators. The simultaneous determination of mechanical and electrical properties of thin sensor films by resonant sensors enables the detection of CO in hydrogen-containing atmospheres. (topical review)

  7. High-temperature bulk acoustic wave sensors

    Science.gov (United States)

    Fritze, Holger

    2011-01-01

    -van Dyke equivalent circuit extended by a finite bulk resistance. Assignments of the lumped elements to the physical properties are given. Finally, an application example demonstrates the capabilities of high-temperature stable piezoelectric resonators. The simultaneous determination of mechanical and electrical properties of thin sensor films by resonant sensors enables the detection of CO in hydrogen-containing atmospheres.

  8. Hydrogen concentration and distribution in high-purity germanium crystals

    International Nuclear Information System (INIS)

    Hansen, W.L.; Haller, E.E.; Luke, P.N.

    1981-10-01

    High-purity germanium crystals used for making nuclear radiation detectors are usually grown in a hydrogen ambient from a melt contained in a high-purity silica crucible. The benefits and problems encountered in using a hydrogen ambient are reviewed. A hydrogen concentration of about 2 x 10 15 cm -3 has been determined by growing crystals in hydrogen spiked with tritium and counting the tritium β-decays in detectors made from these crystals. Annealing studies show that the hydrogen is strongly bound, either to defects or as H 2 with a dissociation energy > 3 eV. This is lowered to 1.8 eV when copper is present. Etching defects in dislocation-free crystals grown in hydrogen have been found by etch stripping to have a density of about 1 x 10 7 cm -3 and are estimated to contain 10 8 H atoms each

  9. High-pressure torsion for new hydrogen storage materials.

    Science.gov (United States)

    Edalati, Kaveh; Akiba, Etsuo; Horita, Zenji

    2018-01-01

    High-pressure torsion (HPT) is widely used as a severe plastic deformation technique to create ultrafine-grained structures with promising mechanical and functional properties. Since 2007, the method has been employed to enhance the hydrogenation kinetics in different Mg-based hydrogen storage materials. Recent studies showed that the method is effective not only for increasing the hydrogenation kinetics but also for improving the hydrogenation activity, for enhancing the air resistivity and more importantly for synthesizing new nanostructured hydrogen storage materials with high densities of lattice defects. This manuscript reviews some major findings on the impact of HPT process on the hydrogen storage performance of different titanium-based and magnesium-based materials.

  10. Influence of temperature on hydrogen production from bread mill wastewater by sewage sludge

    Energy Technology Data Exchange (ETDEWEB)

    Tang, G.L.; Huang, J.; Li, Y.Y.; Sun, Z.J. [China Agricultural Univ., Beijing (China). College of Resources and Environmental Sciences; Tang, Q.Q. [Nanjing Univ., Nanjing (China). Medical School

    2008-07-01

    Hydrogen (H{sub 2}) energy has been touted as a sustainable and clean energy source that can solve environmental problems such as acid rain, greenhouse gases and transboundary pollution. While most hydrogen is currently produced from nonrenewable sources such as oil, natural gas, and coal, these processes are energy-intensive and costly. The biological production of hydrogen using fermentative bacteria is an environmentally friendly and energy-saving process which has recently attracted much attention as an effective way of converting biomass into H{sub 2}. Waste-based H{sub 2} production processes mainly include wastewater from paper mills, municipal solid waste, rice winery wastewater, and food wastewater from cafeterias. This study investigated the use of bread mill wastewater for biological production of hydrogen due to its high production potential. Annual bread production in China is estimated to be over 1.5 million tons, producing 10 m{sup 3} of wastewater per ton of bread. The wastewater has high chemical oxygen demand and carbohydrate concentrations and is therefore suitable for anaerobic treatment processes. This study evaluated the effect of temperature on H{sub 2} production from bread mill wastewater by sewage sludge in lab-scale experiments. H{sub 2} production, the distribution of volatile fatty acids and the lag-phase time were influenced by temperature. H{sub 2} production and H{sub 2} yield increased with increasing temperature. The optimal temperature for H{sub 2} production was 50 degrees C. Butyrate, acetate and alcohol were the main by-products of H{sub 2} fermentation. According to 16S rDNA analysis, the dominant microflora was Clostridium, but the microbial species varied with temperature. The activation energy for H{sub 2} production was estimated to be 92 kJ per mol for bread mill wastewater. It was concluded that bread mill wastewater could potentially serve as a substrate for H{sub 2} production. This research provides a means of

  11. Two-step gasification of cattle manure for hydrogen-rich gas production: Effect of biochar preparation temperature and gasification temperature.

    Science.gov (United States)

    Xin, Ya; Cao, Hongliang; Yuan, Qiaoxia; Wang, Dianlong

    2017-10-01

    Two-step gasification process was proposed to dispose cattle manure for hydrogen rich gas production. The effect of temperature on product distribution and biochar properties were first studied in the pyrolysis-carbonization process. The steam gasification of biochar derived from different pyrolysis-carbonization temperatures was then performed at 750°C and 850°C. The biochar from the pyrolysis-carbonization temperatures of 500°C had high carbon content and low volatiles content. According to the results of gasification stage, the pyrolysis-carbonization temperature of 500°C and the gasification temperature of 850°C were identified as the suitable conditions for hydrogen production. We obtained 1.61m 3 /kg of syngas production, 0.93m 3 /kg of hydrogen yield and 57.58% of hydrogen concentration. This study shows that two-step gasification is an efficient waste-to-hydrogen energy process. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Efficiency of poly-generating high temperature fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Margalef, Pere; Brown, Tim; Brouwer, Jacob; Samuelsen, Scott [National Fuel Cell Research Center (NFCRC), University of California, Irvine, CA 92697-3550 (United States)

    2011-02-15

    High temperature fuel cells can be designed and operated to poly-generate electricity, heat, and useful chemicals (e.g., hydrogen) in a variety of configurations. The highly integrated and synergistic nature of poly-generating high temperature fuel cells, however, precludes a simple definition of efficiency for analysis and comparison of performance to traditional methods. There is a need to develop and define a methodology to calculate each of the co-product efficiencies that is useful for comparative analyses. Methodologies for calculating poly-generation efficiencies are defined and discussed. The methodologies are applied to analysis of a Hydrogen Energy Station (H{sub 2}ES) showing that high conversion efficiency can be achieved for poly-generation of electricity and hydrogen. (author)

  13. High Conversion of Styrene, Ethylene, and Hydrogen to Linear Monoalkylbenzenes

    Directory of Open Access Journals (Sweden)

    David Hermann Lamparelli

    2018-05-01

    Full Text Available 1-Alkylbenzenes as a precursor of surfactants, can be produced from ethylene, styrene, and hydrogen. These intermediates, lacking tertiary carbons, are environmentally more benign than commercial ones that bear the aromatic ring linked to an internal carbon of the aliphatic chain. The one-pot synthesis of highly linear 1-alkylbenzenes (LABs through the homogeneous catalysis of olefin poly-insertion from cheap and largely available reagents can be carried out with a high turnover and selectivity. A purposely designed reactor that allows for the fine control of the three components feed, along with temperature, plays a key role in this achievement. A turnover of 194 g of LABs per mmol of catalyst per hour can be obtained with the simultaneous removal of polyethylene as a by-product.

  14. Metalized T graphene: A reversible hydrogen storage material at room temperature

    International Nuclear Information System (INIS)

    Ye, Xiao-Juan; Zhong, Wei; Du, You-Wei; Liu, Chun-Sheng; Zeng, Zhi

    2014-01-01

    Lithium (Li)-decorated graphene is a promising hydrogen storage medium due to its high capacity. However, homogeneous mono-layer coating graphene with lithium atoms is metastable and the lithium atoms would cluster on the surface, resulting in the poor reversibility. Using van der Waals-corrected density functional theory, we demonstrated that lithium atoms can be homogeneously dispersed on T graphene due to a nonuniform charge distribution in T graphene and strong hybridizations between the C-2p and Li-2p orbitals. Thus, Li atoms are not likely to form clusters, indicating a good reversible hydrogen storage. Both the polarization mechanism and the orbital hybridizations contribute to the adsorption of hydrogen molecules (storage capacity of 7.7 wt. %) with an optimal adsorption energy of 0.19 eV/H 2 . The adsorption/desorption of H 2 at ambient temperature and pressure is also discussed. Our results can serve as a guide in the design of new hydrogen storage materials based on non-hexagonal graphenes.

  15. High temperature corrosion of metals

    International Nuclear Information System (INIS)

    Quadakkers, W.J.; Schuster, H.; Ennis, P.J.

    1988-08-01

    This paper covers three main topics: 1. high temperature oxidation of metals and alloys, 2. corrosion in sulfur containing environments and 3. structural changes caused by corrosion. The following 21 subjects are discussed: Influence of implanted yttrium and lanthanum on the oxidation behaviour of beta-NiA1; influence of reactive elements on the adherence and protective properties of alumina scales; problems related to the application of very fine markers in studying the mechanism of thin scale formation; oxidation behaviour of chromia forming Co-Cr-Al alloys with or without reactive element additions; growth and properties of chromia-scales on high-temperature alloys; quantification of the depletion zone in high temperature alloys after oxidation in process gas; effects of HC1 and of N2 in the oxidation of Fe-20Cr; investigation under nuclear safety aspects of Zircaloy-4 oxidation kinetics at high temperatures in air; on the sulfide corrosion of metallic materials; high temperature sulfide corrosion of Mn, Nb and Nb-Si alloys; corrosion behaviour or NiCrAl-based alloys in air and air-SO2 gas mixtures; sulfidation of cobalt at high temperatures; preoxidation for sulfidation protection; fireside corrosion and application of additives in electric utility boilers; transport properties of scales with complex defect structures; observations of whiskers and pyramids during high temperature corrosion of iron in SO2; corrosion and creep of alloy 800H under simulated coal gasification conditions; microstructural changes of HK 40 cast alloy caused by exploitation in tubes in steam reformer installation; microstructural changes during exposure in corrosive environments and their effect on mechanical properties; coatings against carburization; mathematical modeling of carbon diffusion and carbide precipitation in Ni-Cr-based alloys. (MM)

  16. Detonation cell size measurements and predictions in hydrogen-air-steam mixtures at elevated temperatures

    International Nuclear Information System (INIS)

    Ciccarelli, G.; Ginsberg, T.; Boccio, J.; Economos, C.

    1994-01-01

    The present research reports on the effect of initial mixture temperature on the experimentally measured detonation cell size for hydrogen-air-steam mixtures. Experimental and theoretical research related to combustion phenomena in hydrogen-air-steam mixtures has been ongoing for many years. However, detonation cell size data currently exists or hydrogen-air-steam mixtures up to a temperature of only 400K. Sever accident scenarios have been identified for light water reactors (LWRs) where hydrogen-air mixture temperatures in excess of 400K could be generated within containment. The experiments in this report focus on extending the cell size data base for initial mixture temperatures in excess of 400K. The experiments were carried out in a 10-cm inner-diameter, 6.1-m long heated detonation tube with a maximum operating temperature of 700K and spatial temperature uniformity of ±14K. Detonation cell size measurements provide clear evidence that the effect of hydrogen-air initial gas mixture temperature, in the range 300K--650K, is to decrease cell size and, hence, to increase the sensitivity of the mixture to undergo detonations. The effect of steam content, at any given temperature, is to increase the cell size and, thereby, to decrease the sensitivity of stoichiometric hydrogen-air mixtures. The hydrogen-air detonability limits for the 10-cm inside-diameter test vessel, based upon the onset of single-head spin, decreased from 15 percent by hydrogen at 300K down to about 9 percent hydrogen at 650K. The one-dimensional ZND model does a very good job at predicting the overall trends in the cell size data over the range of hydrogen-air-steam mixture compositions and temperature studied in the experiments

  17. Medium temperature reaction between lanthanide and actinide carbides and hydrogen

    International Nuclear Information System (INIS)

    Dean, G.; Lorenzelli, R.; Pascard, R.

    1964-01-01

    Hydrogen is fixed reversibly by the lanthanide and actinide mono carbides in the range 25 - 400 C, as for pure corresponding metals. Hydrogen goes into the carbides lattice through carbon vacancies and the total fixed amount is approximately equal to two hydrogen atoms per initial vacancy. Final products c.n thus be considered as carbo-hydrides of general formula M(C 1-x , H 2x ). The primitive CFC, NaCl type, structure remains unchanged but expands strongly in the case of actinide carbides. With lanthanide carbides, hydrogenation induces a phase transformation with reappearance of the metal structure (HCP). Hydrogen decomposition pressures of all the studied carbo-hydrides are greater than those of the corresponding di-hydrides. (authors) [fr

  18. High temperature electronic gain device

    International Nuclear Information System (INIS)

    McCormick, J.B.; Depp, S.W.; Hamilton, D.J.; Kerwin, W.J.

    1979-01-01

    An integrated thermionic device suitable for use in high temperature, high radiation environments is described. Cathode and control electrodes are deposited on a first substrate facing an anode on a second substrate. The substrates are sealed to a refractory wall and evacuated to form an integrated triode vacuum tube

  19. RPC operation at high temperature

    CERN Document Server

    Aielli, G; Cardarelli, R; Di Ciaccio, A; Di Stante, L; Liberti, B; Paoloni, A; Pastori, E; Santonico, R

    2003-01-01

    The resistive electrodes of RPCs utilised in several current experiments (ATLAS, CMS, ALICE, BABAR and ARGO) are made of phenolic /melaminic polymers, with room temperature resistivities ranging from 10**1**0 Omega cm, for high rate operation in avalanche mode, to 5 multiplied by 10**1**1 Omega cm, for streamer mode operation at low rate. The resistivity has however a strong temperature dependence, decreasing exponentially with increasing temperature. We have tested several RPCs with different electrode resistivities in avalanche as well as in streamer mode operation. The behaviours of the operating current and of the counting rate have been studied at different temperatures. Long-term operation has also been studied at T = 45 degree C and 35 degree C, respectively, for high and low resistivity electrodes RPCs.

  20. Hydrogen-induced room-temperature plasticity in TC4 and TC21 alloys

    DEFF Research Database (Denmark)

    Yuan, Baoguo; Jin, Yongyue; Hong, Chuanshi

    2017-01-01

    In order to reveal the effect of hydrogen on the room-temperature plasticity of the titanium alloys TC4 and TC21, compression tests have been carried out at room temperature. Results show that an appropriate amount of hydrogen can improve the room-temperature plasticity of both the TC4 and TC21...... alloys. The ultimate compression strain of the TC4 alloy containing a hydrogen concentration of 0.5 wt.% increases by 39% compared to the untreated material. For the TC21 alloy the ultimate compression strain is increased by 33% at a hydrogen concentration of 0.6 wt.%. The main reason for the improvement...... of hydrogen-induced room-temperature plasticity of the TC4 and TC21 alloys is discussed....

  1. HIgh Temperature Photocatalysis over Semiconductors

    Science.gov (United States)

    Westrich, Thomas A.

    Due in large part to in prevalence of solar energy, increasing demand of energy production (from all sources), and the uncertain future of petroleum energy feedstocks, solar energy harvesting and other photochemical systems will play a major role in the developing energy market. This dissertation focuses on a novel photochemical reaction process: high temperature photocatalysis (i.e., photocatalysis conducted above ambient temperatures, T ≥ 100°C). The overarching hypothesis of this process is that photo-generated charge carriers are able to constructively participate in thermo-catalytic chemical reactions, thereby increasing catalytic rates at one temperature, or maintaining catalytic rates at lower temperatures. The photocatalytic oxidation of carbon deposits in an operational hydrocarbon reformer is one envisioned application of high temperature photocatalysis. Carbon build-up during hydrocarbon reforming results in catalyst deactivation, in the worst cases, this was shown to happen in a period of minutes with a liquid hydrocarbon. In the presence of steam, oxygen, and above-ambient temperatures, carbonaceous deposits were photocatalytically oxidized over very long periods (t ≥ 24 hours). This initial experiment exemplified the necessity of a fundamental assessment of high temperature photocatalytic activity. Fundamental understanding of the mechanisms that affect photocatalytic activity as a function of temperatures was achieved using an ethylene photocatalytic oxidation probe reaction. Maximum ethylene photocatalytic oxidation rates were observed between 100 °C and 200 °C; the maximum photocatalytic rates were approximately a factor of 2 larger than photocatalytic rates at ambient temperatures. The loss of photocatalytic activity at temperatures above 200 °C is due to a non-radiative multi-phonon recombination mechanism. Further, it was shown that the fundamental rate of recombination (as a function of temperature) can be effectively modeled as a

  2. High temperature thermoelectric energy conversion

    International Nuclear Information System (INIS)

    Wood, C.

    1986-01-01

    Considerable advances were made in the late '50's and early early '60's in the theory and development of materials for high-temperature thermoelectric energy conversion. This early work culminated in a variety of materials, spanning a range of temperatures, with the product of the figure of merit, Z, and temperature, T, i.e., the dimensionless figure of merit, ZT, of the order of one. This experimental limitation appeared to be universal and led a number of investigators to explore the possibility that a ZT - also represents a theoretical limitation. It was found not to be so

  3. An experimental investigation of the rate of hydrogen absorption in zirconium-2.5 wt percent niobium from steam/hydrogen mixtures at elevated temperatures

    International Nuclear Information System (INIS)

    Langman, V.J.

    1984-08-01

    The test specifications for an experimental program to study the rate of hydrogen absorption in zirconium-2.5 weight percent niobium pressure tube material from steam/hydrogen mixtures at elevated temperatures are discussed

  4. Computer code validation by high temperature chemistry

    International Nuclear Information System (INIS)

    Alexander, C.A.; Ogden, J.S.

    1988-01-01

    At least five of the computer codes utilized in analysis of severe fuel damage-type events are directly dependent upon or can be verified by high temperature chemistry. These codes are ORIGEN, CORSOR, CORCON, VICTORIA, and VANESA. With the exemption of CORCON and VANESA, it is necessary that verification experiments be performed on real irradiated fuel. For ORIGEN, the familiar knudsen effusion cell is the best choice and a small piece of known mass and known burn-up is selected and volatilized completely into the mass spectrometer. The mass spectrometer is used in the integral mode to integrate the entire signal from preselected radionuclides, and from this integrated signal the total mass of the respective nuclides can be determined. For CORSOR and VICTORIA, experiments with flowing high pressure hydrogen/steam must flow over the irradiated fuel and then enter the mass spectrometer. For these experiments, a high pressure-high temperature molecular beam inlet must be employed. Finally, in support of VANESA-CORCON, the very highest temperature and molten fuels must be contained and analyzed. Results from all types of experiments will be discussed and their applicability to present and future code development will also be covered

  5. Effect of trapping and temperature on the hydrogen embrittlement susceptibility of alloy 718

    Energy Technology Data Exchange (ETDEWEB)

    Galliano, Florian; Andrieu, Eric; Blanc, Christine; Cloue, Jean-Marc; Connetable, Damien; Odemer, Gregory, E-mail: gregory.odemer@ensiacet.fr

    2014-08-12

    Ni-based alloy 718 is widely used to manufacture structural components in the aeronautic and nuclear industries. Numerous studies have shown that alloy 718 may be sensitive to hydrogen embrittlement. In the present study, the susceptibilities of three distinct metallurgical states of alloy 718 to hydrogen embrittlement were investigated to identify both the effect of hydrogen trapping on hydrogen embrittlement and the role of temperature in the hydrogen-trapping mechanism. Cathodic charging in a molten salt bath was used to saturate the different hydrogen traps of each metallurgical state. Tensile tests at different temperatures and different strain rates were carried out to study the effect of hydrogen on mechanical properties and failure modes, in combination with hydrogen content measurements. The results demonstrated that Ni-based superalloy 718 was strongly susceptible to hydrogen embrittlement between 25 °C and 300 °C, and highlighted the dominant roles played by the hydrogen solubility and the hydrogen trapping on mechanical behavior and fracture modes.

  6. Fusion reactors-high temperature electrolysis (HTE)

    International Nuclear Information System (INIS)

    Fillo, J.A.

    1978-01-01

    Results of a study to identify and develop a reference design for synfuel production based on fusion reactors are given. The most promising option for hydrogen production was high-temperature electrolysis (HTE). The main findings of this study are: 1. HTE has the highest potential efficiency for production of synfuels from fusion; a fusion to hydrogen energy efficiency of about 70% appears possible with 1800 0 C HTE units and 60% power cycle efficiency; an efficiency of about 50% possible with 1400 0 C HTE units and 40% power cycle efficiency. 2. Relative to thermochemical or direct decomposition methods HTE technology is in a more advanced state of development, 3. Thermochemical or direct decomposition methods must have lower unit process or capital costs if they are to be more attractive than HTE. 4. While design efforts are required, HTE units offer the potential to be quickly run in reverse as fuel cells to produce electricity for restart of Tokamaks and/or provide spinning reserve for a grid system. 5. Because of the short timescale of the study, no detailed economic evaluation could be carried out.A comparison of costs could be made by employing certain assumptions. For example, if the fusion reactor-electrolyzer capital installation is $400/(KW(T) [$1000/KW(E) equivalent], the H 2 energy production cost for a high efficiency (about 70 %) fusion-HTE system is on the same order of magnitude as a coal based SNG plant based on 1976 dollars. 6. The present reference design indicates that a 2000 MW(th) fusion reactor could produce as much at 364 x 10 6 scf/day of hydrogen which is equivalent in heating value to 20,000 barrels/day of gasoline. This would fuel about 500,000 autos based on average driving patterns. 7. A factor of three reduction in coal feed (tons/day) could be achieved for syngas production if hydrogen from a fusion-HTE system were used to gasify coal, as compared to a conventional syngas plant using coal-derived hydrogen

  7. High Temperature Transparent Furnace Development

    Science.gov (United States)

    Bates, Stephen C.

    1997-01-01

    This report describes the use of novel techniques for heat containment that could be used to build a high temperature transparent furnace. The primary objective of the work was to experimentally demonstrate transparent furnace operation at 1200 C. Secondary objectives were to understand furnace operation and furnace component specification to enable the design and construction of a low power prototype furnace for delivery to NASA in a follow-up project. The basic approach of the research was to couple high temperature component design with simple concept demonstration experiments that modify a commercially available transparent furnace rated at lower temperature. A detailed energy balance of the operating transparent furnace was performed, calculating heat losses through the furnace components as a result of conduction, radiation, and convection. The transparent furnace shells and furnace components were redesigned to permit furnace operation at at least 1200 C. Techniques were developed that are expected to lead to significantly improved heat containment compared with current transparent furnaces. The design of a thermal profile in a multizone high temperature transparent furnace design was also addressed. Experiments were performed to verify the energy balance analysis, to demonstrate some of the major furnace improvement techniques developed, and to demonstrate the overall feasibility of a high temperature transparent furnace. The important objective of the research was achieved: to demonstrate the feasibility of operating a transparent furnace at 1200 C.

  8. Thermoanalytical investigation of the hydrogen absorption behaviour of Sm{sub 2}Fe{sub 17-x}Ga{sub x} at high hydrogen pressures

    Energy Technology Data Exchange (ETDEWEB)

    Handstein, A.; Kubis, M.; Gebel, B.; Mueller, K.-H.; Schultz, L. [Institut fuer Festkoerper- und Werkstofforschung Dresden e.V. (Germany). Inst. fuer Metallische Werkstoffe; Gutfleisch, O.; Harris, I.R. [Institut fuer Festkoerper- und Werkstofforschung Dresden e.V. (Germany). Inst. fuer Metallische Werkstoffe]|[Birmingham Univ. (United Kingdom). School of Metallurgy and Materials

    1998-07-01

    The complete disproportionation of Sm{sub 2}Fe{sub 17-x}Ga{sub x} during annealing in hydrogen is hindered due to an increased stability of the compounds with a higher Ga content (x {>=} 1). Therefore the HD process as the first step of HDDR (hydrogenation-disproportionation-desorption-recombination) has to be carried out at a high hydrogen pressure for x {>=} 1. The hydrogen absorption behaviour of Sm{sub 2}Fe{sub 17-x}Ga{sub x} (x = 0, 0.5, 1 and 2) was investigated by means of hydrogen differential thermal analysis (HDTA) and high pressure differential scanning calorimetry (HPDSC) at hydrogen pressures up to 70 bar. A dependency of hydrogenation and disproportionation temperatures on hydrogen pressure and Ga content was found. The comparison with other substituents (M = Al and Si) instead of M = Ga showed an increased stability of Sm{sub 2}Fe{sub 17-x}M{sub x} compounds against disproportionation by hydrogen in the sequence Al, Ga and Si. The Curie temperatures of the interstitially hydrogenated Th{sub 2}Zn{sub 17}-type materials increase with the hydrogen pressure. In order to produce coercive and thermally stable Sm{sub 2}Fe{sub 15}Ga{sub 2}C{sub y} powder by means of the HDDR process, we recombined material disproportionated at different hydrogen pressures. Preliminary results of magnetic properties of this HDDR treated and gas-carburized Sm{sub 2}Fe{sub 15}Ga{sub 2}C{sub y} are discussed. (orig.)

  9. Hydrogen Pressurization of LOX: High Risk/High Reward (Preprint)

    National Research Council Canada - National Science Library

    Turner, Andrew E; Leichner, Aaron

    2006-01-01

    ... filled with hydrogen gas. Airship commercial service, enabled by relatively low-cost hydrogen, died along with the longest vehicle ever to fly, even though thousands of passengers had been transported without incident prior to that time...

  10. "Green" High-Temperature Polymers

    Science.gov (United States)

    Meador, Michael A.

    1998-01-01

    PMR-15 is a processable, high-temperature polymer developed at the NASA Lewis Research Center in the 1970's principally for aeropropulsion applications. Use of fiber-reinforced polymer matrix composites in these applications can lead to substantial weight savings, thereby leading to improved fuel economy, increased passenger and payload capacity, and better maneuverability. PMR-15 is used fairly extensively in military and commercial aircraft engines components seeing service temperatures as high as 500 F (260 C), such as the outer bypass duct for the F-404 engine. The current world-wide market for PMR-15 materials (resins, adhesives, and composites) is on the order of $6 to 10 million annually.

  11. High-temperature metallography setup

    International Nuclear Information System (INIS)

    Blumenfeld, M.; Shmarjahu, D.; Elfassy, S.

    1979-06-01

    A high-temperature metallography setup is presented. In this setup the observation of processes such as that of copper recrystallization was made possible, and the structure of metals such as uranium could be revealed. A brief historical review of part of the research works that have been done with the help of high temperature metallographical observation technique since the beginning of this century is included. Detailed description of metallographical specimen preparation technique and theoretical criteria based on the rate of evaporation of materials present on the polished surface of the specimens are given

  12. High temperature corrosion in gasifiers

    Directory of Open Access Journals (Sweden)

    Bakker Wate

    2004-01-01

    Full Text Available Several commercial scale coal gasification combined cycle power plants have been built and successfully operated during the last 5-10 years. Supporting research on materials of construction has been carried out for the last 20 years by EPRI and others. Emphasis was on metallic alloys for heat exchangers and other components in contact with hot corrosive gases at high temperatures. In this paper major high temperature corrosion mechanisms, materials performance in presently operating gasifiers and future research needs will be discussed.

  13. Reducibility of ceria-lanthana mixed oxides under temperature programmed hydrogen and inert gas flow conditions

    International Nuclear Information System (INIS)

    Bernal, S.; Blanco, G.; Cifredo, G.; Perez-Omil, J.A.; Pintado, J.M.; Rodriguez-Izquierdo, J.M.

    1997-01-01

    The present paper deals with the preparation and characterization of La/Ce mixed oxides, with La molar contents of 20, 36 and 57%. We carry out the study of the structural, textural and redox properties of the mixed oxides, comparing our results with those for pure ceria. For this aim we use temperature programmed reduction (TPR), temperature programmed desorption (TPD), nitrogen physisorption at 77 K, X-ray diffraction and high resolution electron microscopy. The mixed oxides are more easy to reduce in a flow of hydrogen than ceria. Moreover, in an inert gas flow they release oxygen in higher amounts and at lower temperatures than pure CeO 2 . The textural stability of the mixed oxides is also improved by incorporation of lanthana. All these properties make the ceria-lanthana mixed oxides interesting alternative candidates to substitute ceria in three-way catalyst formulations. (orig.)

  14. DETERMINATION OF HYDROGEN DESORBED THROUGH THERMAL CALORIMETRY IN A HIGH STRENGTH STEEL

    Directory of Open Access Journals (Sweden)

    Carolina A. Asmus

    2014-03-01

    Full Text Available The following study aims to quantify the release activation energy (Ea of hydrogen (H from lattice sites, reversible or irreversible, where the H can be trapped. Moreover, enthalpy changes associated with the main hydrogen (H trapping sites can be analyzed by means of differential scanning calorimetry (DSC. In this technique, the peak temperature measurement is determined at two different heating rates, 3ºC/min y 5ºC/min, from ambient temperature to 500°C. In order to simulate severe conditions of hydrogen income into resulfurized high strength steel, electrolytic permeation tests were performed on test tubes suitable for fatigue tests. Sometimes during charging, H promoters were aggregated to electrolytic solution. Subsequently, the test tubes were subjected to flow cycle fatigue tests. Finally, irreversible trap which anchor more strongly H atoms are MnS inclusions. Its role on hydrogen embrittlement during fatigue tests is conclusive.

  15. High temperature creep of vanadium

    International Nuclear Information System (INIS)

    Juhasz, A.; Kovacs, I.

    1978-01-01

    The creep behaviour of polycrystalline vanadium of 99.7% purity has been investigated in the temperature range 790-880 0 C in a high temperature microscope. It was found that the creep properties depend strongly on the history of the sample. To take this fact into account some additional properties such as the dependence of the yield stress and the microhardness on the pre-annealing treatment have also been studied. Samples used in creep measurements were selected on the basis of their microhardness. The activation energy of creep depends on the microhardness and on the creep temperature. In samples annealed at 1250 0 C for one hour (HV=160 kgf mm -2 ) the rate of creep is controlled by vacancy diffusion in the temperature range 820-880 0 C with an activation energy of 78+-8 kcal mol -1 . (Auth.)

  16. ZIF-8 immobilized nickel nanoparticles: highly effective catalysts for hydrogen generation from hydrolysis of ammonia borane.

    Science.gov (United States)

    Li, Pei-Zhou; Aranishi, Kengo; Xu, Qiang

    2012-03-28

    Highly dispersed Ni nanoparticles have been successfully immobilized by the zeolitic metal-organic framework ZIF-8 via sequential deposition-reduction methods, which show high catalytic activity and long durability for hydrogen generation from hydrolysis of aqueous ammonia borane (NH(3)BH(3)) at room temperature. This journal is © The Royal Society of Chemistry 2012

  17. New perspectives on potential hydrogen storage materials using high pressure.

    Science.gov (United States)

    Song, Yang

    2013-09-21

    In addressing the global demand for clean and renewable energy, hydrogen stands out as the most suitable candidate for many fuel applications that require practical and efficient storage of hydrogen. Supplementary to the traditional hydrogen storage methods and materials, the high-pressure technique has emerged as a novel and unique approach to developing new potential hydrogen storage materials. Static compression of materials may result in significant changes in the structures, properties and performance that are important for hydrogen storage applications, and often lead to the formation of unprecedented phases or complexes that have profound implications for hydrogen storage. In this perspective article, 22 types of representative potential hydrogen storage materials that belong to four major classes--simple hydride, complex hydride, chemical hydride and hydrogen containing materials--were reviewed. In particular, their structures, stabilities, and pressure-induced transformations, which were reported in recent experimental works together with supporting theoretical studies, were provided. The important contextual aspects pertinent to hydrogen storage associated with novel structures and transitions were discussed. Finally, the summary of the recent advances reviewed and the insight into the future research in this direction were given.

  18. Inactivation of possible micromycete food contaminants using the low-temperature plasma and hydrogen peroxide

    International Nuclear Information System (INIS)

    Čeřovský, M.; Khun, J.; Rusová, K.; Scholtz, V.; Soušková, H.

    2013-01-01

    The inhibition effect of hydrogen peroxide aerosol, low-temperature plasma and their combinations has been studied on several micromycetes spores. The low-temperature plasma was generated in corona discharges in the open air apparatus with hydrogen peroxide aerosol. Micromycete spores were inoculated on the surface of agar plates, exposed solely to the hydrogen peroxide aerosol, corona discharge or their combination. After incubation the diameter of inhibition zone was measured. The solely positive corona discharge exhibits no inactivation effect, the solely negative corona discharge and solely hydrogen peroxide aerosol exhibit the inactivation effect, however their combinations exhibit to be much more effective. Low-temperature plasma and hydrogen peroxide aerosol present a possible alternative method of microbial decontamination of food, food packages or other thermolabile materials

  19. Determination of hydrogen diffusivity and permeability in W near room temperature applying a tritium tracer technique

    International Nuclear Information System (INIS)

    Ikeda, T.; Otsuka, T.; Tanabe, T.

    2011-01-01

    Tungsten is a primary candidate of plasma facing material in ITER and beyond, owing to its good thermal property and low erosion. But hydrogen solubility and diffusivity near ITER operation temperatures (below 500 K) have scarcely studied. Mainly because its low hydrogen solubility and diffusivity at lower temperatures make the detection of hydrogen quite difficult. We have tried to observe hydrogen plasma driven permeation (PDP) through nickel and tungsten near room temperatures applying a tritium tracer technique, which is extremely sensible to detect tritium diluted in hydrogen. The apparent diffusion coefficients for PDP were determined by permeation lag times at first time, and those for nickel and tungsten were similar or a few times larger than those for gas driven permeation (GDP). The permeation rates for PDP in nickel and tungsten were larger than those for GDP normalized to the same gas pressure about 20 and 5 times larger, respectively.

  20. Inactivation of possible micromycete food contaminants using the low-temperature plasma and hydrogen peroxide

    Energy Technology Data Exchange (ETDEWEB)

    Čeřovský, M., E-mail: scholtz@aldebaran.cz [Institute of Chemical Technology in Prague, Department of Food Preservation, Faculty of Food and Biochemical Technology (Czech Republic); Khun, J. [Institute of Chemical Technology in Prague, Department of Physics and Measurements, Faculty of Chemical Engineering (Czech Republic); Rusová, K. [Institute of Chemical Technology in Prague, Department of Food Preservation, Faculty of Food and Biochemical Technology (Czech Republic); Scholtz, V. [Institute of Chemical Technology in Prague, Department of Physics and Measurements, Faculty of Chemical Engineering (Czech Republic); Soušková, H. [Institute of Chemical Technology in Prague, Department of Computing and Control Engineering, Faculty of Chemical Engineering (Czech Republic)

    2013-09-15

    The inhibition effect of hydrogen peroxide aerosol, low-temperature plasma and their combinations has been studied on several micromycetes spores. The low-temperature plasma was generated in corona discharges in the open air apparatus with hydrogen peroxide aerosol. Micromycete spores were inoculated on the surface of agar plates, exposed solely to the hydrogen peroxide aerosol, corona discharge or their combination. After incubation the diameter of inhibition zone was measured. The solely positive corona discharge exhibits no inactivation effect, the solely negative corona discharge and solely hydrogen peroxide aerosol exhibit the inactivation effect, however their combinations exhibit to be much more effective. Low-temperature plasma and hydrogen peroxide aerosol present a possible alternative method of microbial decontamination of food, food packages or other thermolabile materials.

  1. H/D isotope effects in high temperature proton conductors

    DEFF Research Database (Denmark)

    Bonanos, Nikolaos; Huijser, A.; Poulsen, Finn Willy

    2015-01-01

    The atomic mass ratio of ca. 2 between deuterium and hydrogen is the highest for any pair of stable isotopes and results in significant and measurable H/D isotope effects in high temperature proton conductors containing these species. This paper discusses H/D isotope effects manifested in O-H/O-D...

  2. Development and industrial application of catalyzer for low-temperature hydrogenation hydrolysis of Claus tail gas

    Directory of Open Access Journals (Sweden)

    Honggang Chang

    2015-10-01

    Full Text Available With the implementation of more strict national environmental protection laws, energy conservation, emission reduction and clean production will present higher requirements for sulfur recovery tail gas processing techniques and catalyzers. As for Claus tail gas, conventional hydrogenation catalyzers are gradually being replaced by low-temperature hydrogenation catalyzers. This paper concentrates on the development of technologies for low-temperature hydrogenation hydrolysis catalyzers, preparation of such catalyzers and their industrial application. In view of the specific features of SO2 hydrogenation and organic sulfur hydrolysis during low-temperature hydrogenation, a new technical process involving joint application of hydrogenation catalyzers and hydrolysis catalyzers was proposed. In addition, low-temperature hydrogenation catalyzers and low-temperature hydrolysis catalyzers suitable for low-temperature conditions were developed. Joint application of these two kinds of catalyzers may reduce the inlet temperatures in the conventional hydrogenation reactors from 280 °C to 220 °C, at the same time, hydrogenation conversion rates of SO2 can be enhanced to over 99%. To further accelerate the hydrolysis rate of organic sulfur, the catalyzers for hydrolysis of low-temperature organic sulfur were developed. In lab tests, the volume ratio of the total sulfur content in tail gas can be as low as 131 × 10−6 when these two kinds of catalyzers were used in a proportion of 5:5 in volumes. Industrial application of these catalyzers was implemented in 17 sulfur recovery tail gas processing facilities of 15 companies. As a result, Sinopec Jinling Petrochemical Company had outstanding application performances with a tail gas discharging rate lower than 77.9 mg/m3 and a total sulfur recovery of 99.97%.

  3. High-temperature plasma physics

    International Nuclear Information System (INIS)

    Furth, H.P.

    1988-03-01

    Both magnetic and inertial confinement research are entering the plasma parameter range of fusion reactor interest. This paper reviews the individual and common technical problems of these two approaches to the generation of thermonuclear plasmas, and describes some related applications of high-temperature plasma physics

  4. High-Temperature Vibration Damper

    Science.gov (United States)

    Clarke, Alan; Litwin, Joel; Krauss, Harold

    1987-01-01

    Device for damping vibrations functions at temperatures up to 400 degrees F. Dampens vibrational torque loads as high as 1,000 lb-in. but compact enough to be part of helicopter rotor hub. Rotary damper absorbs energy from vibrating rod, dissipating it in turbulent motion of viscous hydraulic fluid forced by moving vanes through small orifices.

  5. Containment of high temperature plasmas

    International Nuclear Information System (INIS)

    Bass, R.W.; Ferguson, H.R.P.; Fletcher, H. Jr.; Gardner, J.; Harrison, B.K.; Larsen, K.M.

    1973-01-01

    Apparatus is described for confining a high temperature plasma which comprises: 1) envelope means shaped to form a toroidal hollow chamber containing a plasma, 2) magnetic field line generating means for confining the plasma in a smooth toroidal shape without cusps. (R.L.)

  6. Chemistry of high temperature superconductors

    CERN Document Server

    1991-01-01

    This review volume contains the most up-to-date articles on the chemical aspects of high temperature oxide superconductors. These articles are written by some of the leading scientists in the field and includes a comprehensive list of references. This is an essential volume for researchers working in the fields of ceramics, materials science and chemistry.

  7. Properties of high temperature SQUIDS

    International Nuclear Information System (INIS)

    Falco, C.M.; Wu, C.T.

    1978-01-01

    A review is given of the present status of weak links and dc and rf biased SQUIDs made with high temperature superconductors. A method for producing reliable, reproducible devices using Nb 3 Sn is outlined, and comments are made on directions future work should take

  8. High temperature component life assessment

    CERN Document Server

    Webster, G A

    1994-01-01

    The aim of this book is to investigate and explain the rapid advances in the characterization of high temperature crack growth behaviour which have been made in recent years, with reference to industrial applications. Complicated mathematics has been minimized with the emphasis placed instead on finding solutions using simplified procedures without the need for complex numerical analysis.

  9. Medium temperature reaction between lanthanide and actinide carbides and hydrogen; Reaction a temperature moyenne entre les monocarbures de lanthanides et d'actinides et l'hydrogene

    Energy Technology Data Exchange (ETDEWEB)

    Dean, G; Lorenzelli, R; Pascard, R [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

    1964-07-01

    Hydrogen is fixed reversibly by the lanthanide and actinide mono carbides in the range 25 - 400 C, as for pure corresponding metals. Hydrogen goes into the carbides lattice through carbon vacancies and the total fixed amount is approximately equal to two hydrogen atoms per initial vacancy. Final products c.n thus be considered as carbo-hydrides of general formula M(C{sub 1-x}, H{sub 2x}). The primitive CFC, NaCl type, structure remains unchanged but expands strongly in the case of actinide carbides. With lanthanide carbides, hydrogenation induces a phase transformation with reappearance of the metal structure (HCP). Hydrogen decomposition pressures of all the studied carbo-hydrides are greater than those of the corresponding di-hydrides. (authors) [French] Les monocarbures d'actinides et de lanthanides fixent reversiblement de l'hydrogene a temperature peu elevee, a peu pres dans les memes conditions que les metaux purs correspondants. L'hydrogene penetre dans le reseau des carbures par l'intermediaire des lacunes de carbone, et la quantite totale fixee est approximativement egale a deux atomes d'hydrogene par lacune initiale. Les produits obtenus peuvent donc etre consideres comme des carbohydrures de formule generale M(C{sub 1-x}, H{sub 2x}). La structure d'origine CFC, type NaCl est conservee, mais avec une forte expansion, dans le cas des carbures d'actinides. En revanche, l'hydrogenation entraine un changement de phase cristalline avec retour a la structure du metal (HC) pour les carbures de lanthanides. Tous les carbohydrures etudies ont des tensions de decomposition en hydrogene superieures a celles des dihydrures correspondants. (auteurs)

  10. Effect of high pressure hydrogen on low-cycle fatigue

    International Nuclear Information System (INIS)

    Rie, K.T.; Kohler, W.

    1979-01-01

    It has been shown that the fatigue life can be influenced in low-cycle range by high pressure hydrogen while the effect of high pressure hydrogen on high-cycle fatigue will not be as significant. The paper reports the details and the results of the investigations of the effect of high pressure hydrogen on the low-cycle endurance of commercially pure titanium. The results of this study indicate that: 1. The degradation of the fatigue life in low-cycle region for commercially pure titanium under high pressure hydrogen can be described by Nsub(cr)sup(α x Δepsilon)sub(pl)sup(=c) 2. The fatigue life decreases with decreasing strain rate. 3. The fatigue life decreases with increasing hydrogen pressure. It was found that the semilogarithmic plot of the fatigue life versus the hydrogen pressure gives a linear relationship. The Sievert's law does not hold in low-cycle fatigue region. 4. HAC in titanium in low-cycle fatigue region is the result of the disolution of hydrogen at the crack tip and of the strain-induced hybride formation. (orig.) 891 RW/orig. 892 RKD [de

  11. Temperature dependence of anti-hydrogen production in the ATHENA experiment

    CERN Document Server

    Bonomi, G; Amsler, Claude; Bouchta, A; Bowe, P; Carraro, C; Cesar, C L; Charlton, M; Doser, Michael; Filippini, V; Fontana, A; Fujiwara, M C; Funakoshi, R; Genova, P; Hangst, J S; Hayano, R S; Jørgensen, L V; Lagomarsino, V; Landua, Rolf; Lindelöf, D; Lodi-Rizzini, E; Macri, M; Madsen, N; Montagna, P; Pruys, H S; Regenfus, C; Riedler, P; Rotondi, A; Testera, G; Variola, A; Van der Werf, D P

    2004-01-01

    The ATHENA experiment recently produced the first sample of cold anti-hydrogen atoms by mixing cold plasmas of anti-protons and positrons. The temperature of the positron plasma was increased by controlled RF heating and the anti-hydrogen production rate was measured. Preliminary results are presented. (8 refs).

  12. Effect of temperature and hydraulic retention time on hydrogen producing granules: Homoacetogenesis and morphological characteristics

    International Nuclear Information System (INIS)

    Abreu, A. A.; Danko, A. S.; Alves, M. M.

    2009-01-01

    The effect of temperature and hydraulic retention time (HRT) on the homoacetogenesisi and on the morphological characteristics of hydrogen producing granules was investigated. Hydrogen was produced using an expanded granular sludge blanket (EGSB) reactor, fed with glucose and L-arabinose, under mesophilic (37 degree centigrade), thermophilic (55 degree centigrade), and hyper thermophilic (70 degree centigrade) conditions. (Author)

  13. High Pressure and Temperature Effects in Polymers

    Science.gov (United States)

    Bucknall, David; Arrighi, Valeria; Johnston, Kim; Condie, Iain

    Elastomers are widely exploited as the basis for seals in gas and fluid pipelines. The underlying behaviour of these elastomer at the high pressure, elevated temperatures they experience in operation is poorly understood. Consequently, the duty cycle of these materials is often deliberately limited to a few hours, and in order to prevent failure, production is stopped in order to change the seals in critical joints. The result is significant time lost due to bringing down production to change the seals as well as knock on financial costs. In order to address the fundamental nature of the elastomers at their intended operating conditions, we are studying the gas permeation behaviour of hydrogenated natural butyl rubber (HNBR) and fluorinated elastomers (FKM) at a high pressure and elevated temperature. We have developed a pressure system that permits gas permeation studies at gas pressures of up to 5000 psi and operating temperatures up to 150° C. In this paper, we will discuss the nature of the permeation behaviour at these extreme operating conditions, and how this relates to the changes in the polymer structure. We will also discuss the use of graphene-polymer thin layer coatings to modify the gas permeation behaviour of the elastomers.

  14. Low temperature removal of surface oxides and hydrocarbons from Ge(100) using atomic hydrogen

    Energy Technology Data Exchange (ETDEWEB)

    Walker, M., E-mail: m.walker@warwick.ac.uk; Tedder, M.S.; Palmer, J.D.; Mudd, J.J.; McConville, C.F.

    2016-08-30

    Highlights: • Preparation of a clean, well-ordered Ge(100) surface with atomic hydrogen. • Surface oxide layers removed by AHC at room temperature, but not hydrocarbons. • Increasing surface temperature during AHC dramatically improves efficiency. • AHC with the surface heated to 250 °C led to a near complete removal of contaminants. • (2 × 1) LEED pattern from IBA and AHC indicates asymmetric dimer reconstruction. - Abstract: Germanium is a group IV semiconductor with many current and potential applications in the modern semiconductor industry. Key to expanding the use of Ge is a reliable method for the removal of surface contamination, including oxides which are naturally formed during the exposure of Ge thin films to atmospheric conditions. A process for achieving this task at lower temperatures would be highly advantageous, where the underlying device architecture will not diffuse through the Ge film while also avoiding electronic damage induced by ion irradiation. Atomic hydrogen cleaning (AHC) offers a low-temperature, damage-free alternative to the common ion bombardment and annealing (IBA) technique which is widely employed. In this work, we demonstrate with X-ray photoelectron spectroscopy (XPS) that the AHC method is effective in removing surface oxides and hydrocarbons, yielding an almost completely clean surface when the AHC is conducted at a temperature of 250 °C. We compare the post-AHC cleanliness and (2 × 1) low energy electron diffraction (LEED) pattern to that obtained via IBA, where the sample is annealed at 600 °C. We also demonstrate that the combination of a sample temperature of 250 °C and atomic H dosing is required to clean the surface. Lower temperatures prove less effective in removal of the oxide layer and hydrocarbons, whilst annealing in ultra-high vacuum conditions only removes weakly bound hydrocarbons. Finally, we examine the subsequent H-termination of an IBA-cleaned sample using XPS, LEED and ultraviolet

  15. Temperature setting and thermal regulation system for liquid hydrogen bubble chamber; Systeme de mise en temperature et de regulation thermique de chambres a bulles a hydrogene liquide

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, J; Prugne, P; Roubeau, P [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

    1961-07-01

    Hydrogen bubble chamber cooling and constant temperature maintenance in the 25/28 deg. K, range by means of liquid hydrogen boiling under atmospheric pressure (20.4 deg. K) need a device, if possible automatic allowing the introduction of a variable amount of cold to counterbalance the heat transfer either static or due to the chamber operation. A variable impedance heat exchanger has been designed, built and experimented for this purpose. This device, which takes little space (less than 1000 cm{sup 3}) allows transfer of a variable cold power between 0 and 500 watts (0 to 50 liter of evaporated hydrogen). (author) [French] Pour le refroidissement des chambres a bulles a hydrogene et pour le maintien d'une temperature constante dans la gamme 25/28 deg. K au moyen d'hydrogene a l'ebullition sous pression atmospherique (20,4 deg. K), on a besoin d'un dispositif, si possible automatique, permettant l'introduction d'une quantite variable de froid pour compenser le transfert de chaleur, soit statique, soit du a l'operation de la chambre. Un echangeur de chaleur a impedance variable a ete concu, construit et essaye pour cet usage. Ce dispositif qui est peu encombrant (en dessous de 1000 cm{sup 3} ) permet le transfert d'une puissance frigorifique, variable entre 0 et 500 watts (0 a 50 litres d'hydrogene evapore). (auteur)

  16. High temperature fusion reactor design

    International Nuclear Information System (INIS)

    Harkness, S.D.; dePaz, J.F.; Gohar, M.Y.; Stevens, H.C.

    1979-01-01

    Fusion energy may have unique advantages over other systems as a source for high temperature process heat. A conceptual design of a blanket for a 7 m tokamak reactor has been developed that is capable of producing 1100 0 C process heat at a pressure of approximately 10 atmospheres. The design is based on the use of a falling bed of MgO spheres as the high temperature heat transfer system. By preheating the spheres with energy taken from the low temperature tritium breeding part of the blanket, 1086 MW of energy can be generated at 1100 0 C from a system that produces 3000 MW of total energy while sustaining a tritium breeding ratio of 1.07. The tritium breeding is accomplished using Li 2 O modules both in front of (6 cm thick) and behind (50 cm thick) the high temperature ducts. Steam is used as the first wall and front tritium breeding module coolant while helium is used in the rear tritium breeding region. The system produces 600 MW of net electricity for use on the grid

  17. High Temperature, High Power Piezoelectric Composite Transducers

    Science.gov (United States)

    Lee, Hyeong Jae; Zhang, Shujun; Bar-Cohen, Yoseph; Sherrit, StewarT.

    2014-01-01

    Piezoelectric composites are a class of functional materials consisting of piezoelectric active materials and non-piezoelectric passive polymers, mechanically attached together to form different connectivities. These composites have several advantages compared to conventional piezoelectric ceramics and polymers, including improved electromechanical properties, mechanical flexibility and the ability to tailor properties by using several different connectivity patterns. These advantages have led to the improvement of overall transducer performance, such as transducer sensitivity and bandwidth, resulting in rapid implementation of piezoelectric composites in medical imaging ultrasounds and other acoustic transducers. Recently, new piezoelectric composite transducers have been developed with optimized composite components that have improved thermal stability and mechanical quality factors, making them promising candidates for high temperature, high power transducer applications, such as therapeutic ultrasound, high power ultrasonic wirebonding, high temperature non-destructive testing, and downhole energy harvesting. This paper will present recent developments of piezoelectric composite technology for high temperature and high power applications. The concerns and limitations of using piezoelectric composites will also be discussed, and the expected future research directions will be outlined. PMID:25111242

  18. Automatic torque magnetometer for vacuum-to-high-pressure hydrogen environments

    International Nuclear Information System (INIS)

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

    1979-01-01

    An automatic torque magnetometer has been developed for use in high-pressure hydrogen. It will contain pressures ranging from vacuum to 200 atm of hydrogen gas at sample temperatures greater than 400 0 C. This magnetometer, which uses an optical lever postion sensor and a restoring force technique has an operating range of 2.0 x 10 3 dyn cm to l.6 x 10 -4 dyn cm. An accompanying digital data collection system extends the sensitivity to 1 x 10 -5 dyn cm as well as increasing the data handling capacity of the system. The magnetic properties of thin films in high-temperature and high-pressure hydrogen environments can be studied using this instruments

  19. Catalysis in high-temperature fuel cells.

    Science.gov (United States)

    Föger, K; Ahmed, K

    2005-02-17

    Catalysis plays a critical role in solid oxide fuel cell systems. The electrochemical reactions within the cell--oxygen dissociation on the cathode and electrochemical fuel combustion on the anode--are catalytic reactions. The fuels used in high-temperature fuel cells, for example, natural gas, propane, or liquid hydrocarbons, need to be preprocessed to a form suitable for conversion on the anode-sulfur removal and pre-reforming. The unconverted fuel (economic fuel utilization around 85%) is commonly combusted using a catalytic burner. Ceramic Fuel Cells Ltd. has developed anodes that in addition to having electrochemical activity also are reactive for internal steam reforming of methane. This can simplify fuel preprocessing, but its main advantage is thermal management of the fuel cell stack by endothermic heat removal. Using this approach, the objective of fuel preprocessing is to produce a methane-rich fuel stream but with all higher hydrocarbons removed. Sulfur removal can be achieved by absorption or hydro-desulfurization (HDS). Depending on the system configuration, hydrogen is also required for start-up and shutdown. Reactor operating parameters are strongly tied to fuel cell operational regimes, thus often limiting optimization of the catalytic reactors. In this paper we discuss operation of an authothermal reforming reactor for hydrogen generation for HDS and start-up/shutdown, and development of a pre-reformer for converting propane to a methane-rich fuel stream.

  20. Room temperature hydrogen generation from hydrolysis of ammonia-borane over an efficient NiAgPd/C catalyst

    KAUST Repository

    Hu, Lei

    2014-12-01

    NiAgPd nanoparticles are successfully synthesized by in-situ reduction of Ni, Ag and Pd salts on the surface of carbon. Their catalytic activity was examined in ammonia borane (NH3BH3) hydrolysis to generate hydrogen gas. This nanomaterial exhibits a higher catalytic activity than those of monometallic and bimetallic counterparts and a stoichiometric amount of hydrogen was produced at a high generation rate. Hydrogen production rates were investigated in different concentrations of NH3BH3 solutions, including in the borates saturated solution, showing little influence of the concentrations on the reaction rates. The hydrogen production rate can reach 3.6-3.8 mol H2 molcat -1 min-1 at room temperature (21 °C). The activation energy and TOF value are 38.36 kJ/mol and 93.8 mol H2 molcat -1 min-1, respectively, comparable to those of Pt based catalysts. This nanomaterial catalyst also exhibits excellent chemical stability, and no significant morphology change was observed from TEM after the reaction. Using this catalyst for continuously hydrogen generation, the hydrogen production rate can be kept after generating 6.2 L hydrogen with over 10,000 turnovers and a TOF value of 90.3 mol H2 molcat -1 min-1.

  1. Photochemically engineering the metal-semiconductor interface for room-temperature transfer hydrogenation of nitroarenes with formic acid.

    Science.gov (United States)

    Li, Xin-Hao; Cai, Yi-Yu; Gong, Ling-Hong; Fu, Wei; Wang, Kai-Xue; Bao, Hong-Liang; Wei, Xiao; Chen, Jie-Sheng

    2014-12-08

    A mild photochemical approach was applied to construct highly coupled metal-semiconductor dyads, which were found to efficiently facilitate the hydrogenation of nitrobenzene. Aniline was produced in excellent yield (>99 %, TOF: 1183) using formic acid as hydrogen source and water as solvent at room temperature. This general and green catalytic process is applicable to a wide range of nitroarenes without the involvement of high-pressure gases or sacrificial additives. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Summary: High Temperature Downhole Motor

    Energy Technology Data Exchange (ETDEWEB)

    Raymond, David W. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2017-10-01

    Directional drilling can be used to enable multi-lateral completions from a single well pad to improve well productivity and decrease environmental impact. Downhole rotation is typically developed with a motor in the Bottom Hole Assembly (BHA) that develops drilling power (speed and torque) necessary to drive rock reduction mechanisms (i.e., the bit) apart from the rotation developed by the surface rig. Historically, wellbore deviation has been introduced by a “bent-sub,” located in the BHA, that introduces a small angular deviation, typically less than 3 degrees, to allow the bit to drill off-axis with orientation of the BHA controlled at the surface. The development of a high temperature downhole motor would allow reliable use of bent subs for geothermal directional drilling. Sandia National Laboratories is pursuing the development of a high temperature motor that will operate on either drilling fluid (water-based mud) or compressed air to enable drilling high temperature, high strength, fractured rock. The project consists of designing a power section based upon geothermal drilling requirements; modeling and analysis of potential solutions; and design, development and testing of prototype hardware to validate the concept. Drilling costs contribute substantially to geothermal electricity production costs. The present development will result in more reliable access to deep, hot geothermal resources and allow preferential wellbore trajectories to be achieved. This will enable development of geothermal wells with multi-lateral completions resulting in improved geothermal resource recovery, decreased environmental impact and enhanced well construction economics.

  3. NSTX High Temperature Sensor Systems

    International Nuclear Information System (INIS)

    McCormack, B.; Kugel, H.W.; Goranson, P.; Kaita, R.

    1999-01-01

    The design of the more than 300 in-vessel sensor systems for the National Spherical Torus Experiment (NSTX) has encountered several challenging fusion reactor diagnostic issues involving high temperatures and space constraints. This has resulted in unique miniature, high temperature in-vessel sensor systems mounted in small spaces behind plasma facing armor tiles, and they are prototypical of possible high power reactor first-wall applications. In the Center Stack, Divertor, Passive Plate, and vessel wall regions, the small magnetic sensors, large magnetic sensors, flux loops, Rogowski Coils, thermocouples, and Langmuir Probes are qualified for 600 degrees C operation. This rating will accommodate both peak rear-face graphite tile temperatures during operations and the 350 degrees C bake-out conditions. Similar sensor systems including flux loops, on other vacuum vessel regions are qualified for 350 degrees C operation. Cabling from the sensors embedded in the graphite tiles follows narrow routes to exit the vessel. The detailed sensor design and installation methods of these diagnostic systems developed for high-powered ST operation are discussed

  4. HYFIRE: a tokamak/high-temperature electrolysis system

    International Nuclear Information System (INIS)

    Fillo, J.A.; Powell, J.P.; Benenati, R.; Varljen, T.C.; Chi, J.W.H.; Karbowski, J.S.

    1981-01-01

    The HYFIRE studies to date have investigated a number of technical approaches for using the thermal energy produced in a high-temperature Tokamak blanket to provide the electrical and thermal energy required to drive a high-temperature (> 1000 0 C) water electrolysis process. Current emphasis is on two design points, one consistent with electrolyzer peak inlet temperatures of 1400 0 C, which is an extrapolation of present experience, and one consistent with a peak electrolyzer temperature of 1100 0 C. This latter condition is based on current laboratory experience with high-temperature solid electrolyte fuel cells. Our major conclusion to date is that the technical integration of fusion and high-temperature electrolysis appears to be feasible and that overall hydrogen production efficiencies of 50 to 55% seem possible

  5. Development of high temperature turbine

    Energy Technology Data Exchange (ETDEWEB)

    Takahara, Kitao; Nouse, Hiroyuki; Yoshida, Toyoaki; Minoda, Mitsuhiro; Matsusue, Katsutoshi; Yanagi, Ryoji

    1988-07-01

    For the contribution to the development of FJR710, high by-pass ratio turbofan engine, with the study for many years of the development of high efficiency turbine for the jet engine, the first technical prize from the Energy Resource Research Committee was awarded in April, 1988. This report introduced its technical contents. In order to improve the thermal efficiency and enlarge the output, it is very effective to raise the gas temperature at the inlet of gas turbine. For its purpose, by cooling the nozzle and moving blades and having those blades operate at lower temperature than that of the working limitation, they realized, for the first time in Japan, the technique of cooling turbine to heighten the operational gas temperature. By that technique, it was enabled to raise the gas temperature at the inlet of turbine, to 1,350/sup 0/C from 850/sup 0/C. This report explain many important points of study covering the basic test, visualizing flow experiment, material discussion and structural design in the process of development. (9 figs)

  6. Interferometric determination of electron density in a high pressure hydrogen arc. 1. Calculation of refraction index

    Energy Technology Data Exchange (ETDEWEB)

    Radtke, R; Guenther, K; Ulbricht, R [Akademie der Wissenschaften der DDR, Berlin. Zentralinstitut fuer Elektronenphysik

    1980-01-14

    The refraction index of a hydrogen plasma in LTE was calculated as a function of the wavelength of observation, temperature and pressure, taking into account bound-bound and bound-free transitions of the neutral atom. According to the present calculation, the influence of excited states at higher temperatures is smaller than indicated by Baum et al (Plasma Phys.; 17: 79 (1975)) for argon. Using the calculations presented here, the interferometric investigation of a high pressure hydrogen arc should allow the determination of the electron density with an accuracy of the order of 1%.

  7. Modelling the influence of austenitisation temperature on hydrogen trapping in Nb containing martensitic steels

    International Nuclear Information System (INIS)

    Lang, Peter; Rath, Markus; Kozeschnik, Ernst; Rivera-Diaz-del-Castillo, Pedro E.J.

    2015-01-01

    Hydrogen trapping behaviour is investigated by means of thermokinetic simulations in a martensitic steel. The heat treatment consists of austenitisation followed by quenching and tempering. The model prescribes a minimum in hydrogen trapping at an austenitisation temperature of 1050 °C. Below this temperature, austenite grain boundaries are the prevailing trap, whereas niobium atoms in solid solution are the main traps above 1050 °C. The model describes precisely the experimental results

  8. Solubility of hydrogen in water in a broad temperature and pressure range

    International Nuclear Information System (INIS)

    Baranenko, V.I.; Kirov, V.S.

    1989-01-01

    In the coolant of water-water reactors, as a result of radiolytic decomposition of water and chemical additives (hydrazine and ammonia) and saturation of the make-up water of the first loop with free hydrogen in order to suppress radiolysis, 30-60 ml/kg of hydrogen is present in normal conditions. On being released from the water, it is free to accumulate in micropores of the metals, resulting in hydrogen embrittlement; gas accumulates in stagnant zones, with deterioration in heat transfer in the first loop and corresponding difficulty in the use of the reactor and the whole reactor loop. To determine the amount of free hydrogen and hydrogen dissolved in water in different elements of the first loop, it is necessary to know the limiting solubility of hydrogen in water at different temperatures and pressures, and also to have the corresponding theoretical dependences. The experimental data on the solubility of hydrogen in water are nonsystematic and do not cover the parameter ranges of modern nuclear power plants (P = 10-30 MPa, T = 260-370C). Therefore, the aim of the present work is to establish a well-founded method of calculating the limiting solubility of hydrogen in water and, on this basis, to compile tables of the limiting solubility of hydrogen in water at pressures 0.1-50 MPa and temperatures 0-370C

  9. Relationship between carbon microstructure, adsorption energy and hydrogen adsorption capacity at different temperatures

    International Nuclear Information System (INIS)

    Jacek Jagiello; Matthias Thommes

    2005-01-01

    Various microporous materials such as activated carbons, nano-tubes, synthetic microporous carbons as well as metal organic framework materials are being considered for hydrogen storage applications by means of physical adsorption. To develop materials of practical significance for hydrogen storage it is important to understand the relationships between pore sizes, adsorption energies and adsorption capacities. The pore size distribution (PSD) characterization is traditionally obtained from the analysis of nitrogen adsorption isotherms measured at 77 K. However, a portion of the pores accessible to H 2 may not be accessible to N 2 at this temperature. Therefore, it was recently proposed to use the DFT analysis of H 2 adsorption isotherms to characterize pore structure of materials considered for hydrogen storage applications. In present work, adsorption isotherms of H 2 and N 2 at cryogenic temperatures are used for the characterization of carbon materials. Adsorption measurements were performed with Autosorb 1 MP (Quantachrome Instruments, Boynton Beach, Florida, USA). As an example, Fig 1 compares PSDs calculated for the activated carbon sample (F400, Calgon Carbon) using combined H 2 and N 2 data, and using N 2 isotherm only. The nitrogen derived PSD does not include certain amount of micropores which are accessible to H 2 but not to N 2 molecules. Obviously, the difference in the calculated PSDs by the two methods will depend on the actual content of small micropores in a given sample. Carbon adsorption properties can also be characterized by the isosteric heat of adsorption, Qst, related to the adsorption energy and dependent on the carbon pore/surface structure. Fig 2 shows Qst data calculated using the Clausius-Clapeyron equation from H 2 isotherms measured at 77 K and 87 K for the carbon molecular sieve CMS 5A (Takeda), oxidized single wall nano-tubes (SWNT), and graphitized carbon black (Supelco). The Qst values decrease with increasing pore sizes. The

  10. High temperature structural sandwich panels

    Science.gov (United States)

    Papakonstantinou, Christos G.

    High strength composites are being used for making lightweight structural panels that are being employed in aerospace, naval and automotive structures. Recently, there is renewed interest in use of these panels. The major problem of most commercial available sandwich panels is the fire resistance. A recently developed inorganic matrix is investigated for use in cases where fire and high temperature resistance are necessary. The focus of this dissertation is the development of a fireproof composite structural system. Sandwich panels made with polysialate matrices have an excellent potential for use in applications where exposure to high temperatures or fire is a concern. Commercial available sandwich panels will soften and lose nearly all of their compressive strength temperatures lower than 400°C. This dissertation consists of the state of the art, the experimental investigation and the analytical modeling. The state of the art covers the performance of existing high temperature composites, sandwich panels and reinforced concrete beams strengthened with Fiber Reinforced Polymers (FRP). The experimental part consists of four major components: (i) Development of a fireproof syntactic foam with maximum specific strength, (ii) Development of a lightweight syntactic foam based on polystyrene spheres, (iii) Development of the composite system for the skins. The variables are the skin thickness, modulus of elasticity of skin and high temperature resistance, and (iv) Experimental evaluation of the flexural behavior of sandwich panels. Analytical modeling consists of a model for the flexural behavior of lightweight sandwich panels, and a model for deflection calculations of reinforced concrete beams strengthened with FRP subjected to fatigue loading. The experimental and analytical results show that sandwich panels made with polysialate matrices and ceramic spheres do not lose their load bearing capability during severe fire exposure, where temperatures reach several

  11. Electrochemical Hydrogen Storage in a Highly Ordered Mesoporous Carbon

    Directory of Open Access Journals (Sweden)

    Dan eLiu

    2014-10-01

    Full Text Available A highly order mesoporous carbon has been synthesized through a strongly acidic, aqueous cooperative assembly route. The structure and morphology of the carbon material were investigated using TEM, SEM and nitrogen adsorption-desorption isotherms. The carbon was proven to be meso-structural and consisted of graphitic micro-domain with larger interlayer space. AC impedance and electrochemical measurements reveal that the synthesized highly ordered mesoporous carbon exhibits a promoted electrochemical hydrogen insertion process and improved capacitance and hydrogen storage stability. The meso-structure and enlarged interlayer distance within the highly ordered mesoporous carbon are suggested as possible causes for the enhancement in hydrogen storage. Both hydrogen capacity in the carbon and mass diffusion within the matrix were improved.

  12. Recovery of high-purity hydrogen from COG

    Energy Technology Data Exchange (ETDEWEB)

    Tsukiyama, Y

    1982-01-01

    A general account of the latest trends in the recovery of high-purity hydrogen from coke oven gas (COG), the article being based on both Japanese and overseas literature: 1) Deep-freeze separation: impurities are liquefied and removed. This method make use of the fact that hydrogen is hard to liquefy. 2) The PSA method: high-purity hydrogen is recovered by the adsorption of other constituents at high pressures. This technique makes use of the fact that the adsorption capacity of an adsorbent varies with the partial pressure of the substances being adsorbed. 3) Membrane separation: a permeation separation method that uses a functional polymer separation membrane, and that depends on the fact that hydrogen has a low molecular weight in comparison with the other constituents. (19 refs.) (In Japanese)

  13. Safety characteristics of hydrogen at super ambient conditions: lubricant contamination influencing the auto ignition temperature

    International Nuclear Information System (INIS)

    Liebner, C.; Schroder, V.; Holtappels, K.

    2006-01-01

    Inventing hydrogen as a commonly used future energy carrier the long term social acceptance as well as the clean energy image strongly depends upon the safety of its applications. The safety characteristics of hydrogen build a special challenge e.g. in the field of combustion engine development. Small impurities from lubricants used in motors and pumps, may serve as radical source, strongly influencing the auto ignition temperature of hydrogen. Auto Ignition Temperature (AIT) of Hydrogen-Air mixtures were measured in closed autoclaves made from stainless steel, similar to the closed bomb method described in the European standard EN 1839. Initial pressures of 10 bar(a) and 30 bar(a) of a premixed stoichiometric hydrogen-air mixture were investigated. Auto ignition can be obtained about 100 K below the standard AIT (560 deg C, atmospheric pressure) and 300 K below the standard AIT when contaminated through motor oil. (authors)

  14. Electrical conductivity of highly ionized dense hydrogen plasma

    International Nuclear Information System (INIS)

    Radtke, R.; Guenther, K.

    1976-01-01

    A diagnostic technique for the determination of pressure, temperature and its radial distribution, the strength of the electric field and the current of a wall-stabilized pulse hydrogen arc at a pressure of 10 atm and a maximum power of 120 kW/cm arc length is developed. (author)

  15. Influence of hydrogen on high cycle fatigue of polycrystalline vanadium

    International Nuclear Information System (INIS)

    Chung, D.W.; Lee, K.S.; Stoloff, N.S.

    1977-02-01

    The room temperature fatigue behavior of several polycrystalline V-H 2 alloys is described. Hydrogen extends the life of unnotched vanadium but has a deleterious effect in notched materials. Crack propagation data are correlated with tensile yield stress and cyclic strain hardening data

  16. Ceramics for high temperature applications

    International Nuclear Information System (INIS)

    Mocellin, A.

    1977-01-01

    Problems related to materials, their fabrication, properties, handling, improvements are examined. Silicium nitride and silicium carbide are obtained by vacuum hot-pressing, reaction sintering and chemical vapour deposition. Micrographs are shown. Mechanical properties i.e. room and high temperature strength, creep resistance fracture mechanics and fatigue resistance. Recent developments of pressureless sintered Si C and the Si-Al-O-N quaternary system are mentioned

  17. High-temperature geothermal cableheads

    Science.gov (United States)

    Coquat, J. A.; Eifert, R. W.

    1981-11-01

    Two high temperature, corrosion resistant logging cable heads which use metal seals and a stable fluid to achieve proper electrical terminations and cable sonde interfacings are described. A tensile bar provides a calibrated yield point, and a cone assembly anchors the cable armor to the head. Electrical problems of the sort generally ascribable to the cable sonde interface were absent during demonstration hostile environment loggings in which these cable heads were used.

  18. Hydrogen absorption/desorption characteristics of room temperature ...

    Indian Academy of Sciences (India)

    ZrMn2-Ni system; metal hydrides; hydrogen storage materials. ... where ∼ 2.5 to 2.9 H/F.U. can be reversibly stored under the ideal operating conditions. ... these are promising candidates for stationary and short range mobile applications.

  19. Hydrogen embrittlement of Zr-2.5Nb PT with temperature

    International Nuclear Information System (INIS)

    Oh, Dong Joon; Ahn, Sang Bok; Kim, Young Suk

    2003-01-01

    The aim of this study is to investigate the effect of hydrogen embrittlement of Zr-2.5Nb CANDU pressure tube. The tests were performed at three hydrogen contents for transverse tensile and CCT specimens while the test temperatures were changed (RT to 300 .deg. C). The specimens were directly machined from the tube retaining original curvature using electric discharge machine. Both the transverse tensile and the fracture toughness tests showed the hydrogen embrittlement clearly at RT but this phenomenon was disappeared while the test temperature arrived over 250 .deg. C

  20. High capacity hydrogen absorption in transition-metal ethylene complexes: consequences of nanoclustering

    International Nuclear Information System (INIS)

    Phillips, A B; Shivaram, B S

    2009-01-01

    We have recently shown that organo-metallic complexes formed by laser ablating transition metals in ethylene are high hydrogen absorbers at room temperature (Phillips and Shivaram 2008 Phys. Rev. Lett. 100 105505). Here we show that the absorption percentage depends strongly on the ethylene pressure. High ethylene pressures (>100 mTorr) result in a lowered hydrogen uptake. Transmission electron microscopy measurements reveal that while low pressure ablations result in metal atoms dispersed uniformly on a near atomic scale, high pressure ones yield distinct nanoparticles with electron energy-loss spectroscopy demonstrating that the metal atoms are confined solely to the nanoparticles.

  1. Determinations of the temperature of terminal solid solubility in dissolution and precipitation of hydrogen/deuterium in irradiated Zircaloy-4

    Energy Technology Data Exchange (ETDEWEB)

    Vizcaino, P [CNEA-CONICET, Centro Atomico Ezeiza (Argentina)

    2012-07-01

    The proposed plan is an approach to the metallurgical consequences of the high neutron fluencies (10''2''2 n/cm''2) on the hydrogen behavior in zirconium based alloys, based on the significance of the microstructural behavior of the high burn up fuel claddings during the dry storage period. The studies are focused on Zircaloy-4, concerning to two processes: Neutron irradiation damage; Hydrogen pick up. The Zircaloy-4 was taken from cooling channels of the PHWR Atucha 1. These components remained more than 10 years in service, reaching neutron fluencies up to 10''2''2 n/cm''2. In the last recent years, measurements of the hydride dissolution temperatures have shown that hydrogen solubility is affected by the neutron irradiation, increasing it respect to the unirradiated Zircaloy solubility. In addition, in this material the amorphization/dissolution of the second phase particles (SPPs) was observed, being proposed an interaction between the hydrogen atoms, the SPPs and the irradiation defects as a possible explanation of the observed behavior. For the present case, attention will be focused on the hydride precipitation process, since it is strongly related with delay hydrogen cracking initiation, a problem of direct concern for the dry storage. The goal of the present proposal is to make an approach to the source of the observed effect, applying several specific techniques as differential scanning calorimetry (DSC), high resolution x-ray diffraction and transmission electron microscopy. The objectives can be divided as follows: Determination of the temperatures of terminal solid solubility in dissolution (TTSSd) and in precipitation (TTSSp) in high fluency irradiated Zircaloy-4, reproducing the temperatures at which the Zircaloy fuel claddings remain during dry storage by an annealing program during the DSC experiments; Observations by optical and transmission electron microscopy of the hydride distribution before (as received material) and after high temperature

  2. Ignition during hydrogen release from high pressure into the atmosphere

    Science.gov (United States)

    Oleszczak, P.; Wolanski, P.

    2010-12-01

    The first investigations concerned with a problem of hydrogen jet ignition, during outflow from a high-pressure vessel were carried out nearly 40 years ago by Wolanski and Wojcicki. The research resulted from a dramatic accident in the Chorzow Chemical Plant Azoty, where the explosion of a synthesis gas made up of a mixture composed of three moles of hydrogen per mole of nitrogen, at 300°C and 30 MPa killed four people. Initial investigation had excluded potential external ignition sources and the main aim of the research was to determine the cause of ignition. Hydrogen is currently considered as a potential fuel for various vehicles such as cars, trucks, buses, etc. Crucial safety issues are of potential concern, associated with the storage of hydrogen at a very high pressure. Indeed, the evidence obtained nearly 40 years ago shows that sudden rupture of a high-pressure hydrogen storage tank or other component can result in ignition and potentially explosion. The aim of the present research is identification of the conditions under which hydrogen ignition occurs as a result of compression and heating of the air by the shock wave generated by discharge of high-pressure hydrogen. Experiments have been conducted using a facility constructed in the Combustion Laboratory of the Institute of Heat Engineering, Warsaw University of Technology. Tests under various configurations have been performed to determine critical conditions for occurrence of high-pressure hydrogen ignition. The results show that a critical pressure exists, leading to ignition, which depends mainly on the geometric configuration of the outflow system, such as tube diameter, and on the presence of obstacles.

  3. Nanoporous Ni with High Surface Area for Potential Hydrogen Storage Application.

    Science.gov (United States)

    Zhou, Xiaocao; Zhao, Haibo; Fu, Zhibing; Qu, Jing; Zhong, Minglong; Yang, Xi; Yi, Yong; Wang, Chaoyang

    2018-06-01

    Nanoporous metals with considerable specific surface areas and hierarchical pore structures exhibit promising applications in the field of hydrogen storage, electrocatalysis, and fuel cells. In this manuscript, a facile method is demonstrated for fabricating nanoporous Ni with a high surface area by using SiO₂ aerogel as a template, i.e., electroless plating of Ni into an SiO₂ aerogel template followed by removal of the template at moderate conditions. The effects of the prepared conditions, including the electroless plating time, temperature of the structure, and the magnetism of nanoporous Ni are investigated in detail. The resultant optimum nanoporous Ni with a special 3D flower-like structure exhibited a high specific surface area of about 120.5 m²/g. The special nanoporous Ni exhibited a promising prospect in the field of hydrogen storage, with a hydrogen capacity of 0.45 wt % on 4.5 MPa at room temperature.

  4. Influence of cold deformation and annealing on hydrogen embrittlement of cold hardening bainitic steel for high strength bolts

    Energy Technology Data Exchange (ETDEWEB)

    Hui, Weijun, E-mail: wjhui@bjtu.edu.cn [School of Mechanical, Electronic and Control Engineering, Beijing Jiaotong University, Beijing 100044 (China); Zhang, Yongjian; Zhao, Xiaoli; Shao, Chengwei [School of Mechanical, Electronic and Control Engineering, Beijing Jiaotong University, Beijing 100044 (China); Wang, Kaizhong; Sun, Wei; Yu, Tongren [Technical Center, Maanshan Iron & Steel Co., Ltd., Maanshan 243002, Anhui (China)

    2016-04-26

    The influence of cold drawing and annealing on hydrogen embrittlement (HE) of newly developed cold hardening bainitic steel was investigated by using slow strain rate testing (SSRT) and thermal desorption spectrometry (TDS), for ensuring safety performance of 10.9 class high strength bolts made of this kind of steel against HE under service environments. Hydrogen was introduced into the specimen by electrochemical charging. TDS analysis shows that the hydrogen-charged cold drawn specimen exhibits an additional low-temperature hydrogen desorption peak besides the original high-temperature desorption peak of the as-rolled specimen, causing remarkable increase of absorbed hydrogen content. It is found that cold drawing significantly enhances the susceptibility to HE, which is mainly attributed to remarkable increase of diffusible hydrogen absorption, the occurrence of strain-induced martensite as well as the increase of strength level. Annealing after cold deformation is an effective way to improve HE resistance and this improvement strongly depends on annealing temperature, i.e. HE susceptibility decreases slightly with increasing annealing temperature up to 200 °C and then decreases significantly with further increasing annealing temperature. This phenomenon is explained by the release of hydrogen, the recovery of cold worked microstructure and the decrease of strength with increasing annealing temperature.

  5. Measurement of effective solvus temperature of hydrogen in Zr - 2. 5 wt % Nb using acoustic emission

    Energy Technology Data Exchange (ETDEWEB)

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

    1978-01-01

    The effect of applied tensile stress on the solvus temperature of hydrogen in cold-worked Zr - 2.5 wt % Nb has been measured using acoustic emission. Hydrides are necessary for delayed hydrogen cracking and the lowest temperature at which hydride cracking cannot be detected by acoustic emission was taken as the solvus temperature. The results show that any effect of tensile stress on terminal solubility, Cs, is undetectable. Between about 2 and 100 ppM hydrogen, the results can be described by: C/sub s/ = 1.40 x 10/sup 5/ exp - (36100/RT) ppM. They also suggest that the equilibrium phase, delta-hydride, is responsible for delayed hydrogen cracking.

  6. Zircaloy behaviour in high temperature irradiated water

    International Nuclear Information System (INIS)

    Urbanic, V.F.

    1982-04-01

    The corrosion and hydriding of Zircaloy during irradiation in high temperature water is strongly dependent on the oxygen concentration of the water. Corrosion tests in the NRX and NRU research reactors using small samples have demonstrated the importance of water chemistry in maintaining Zircaloy corrosion and hydriding within acceptable limits. Zircaloy fuel cladding develops non-uniform, patch-type oxides during irradiation in hich temperature water containing dissolved oxygen. Results from examinations of prototype fuel cladding irradiated in the research reactors are presented to show how local variations in coolant flow, fast neutron flux, metallurgical structure and surface condition can influence the onset of non-uniform corrosion under these conditions. Destructive examinations of CANDU-PHW reactor fuel cladding have emphasized the importance of good chemistry control, especially the dissolved oxygen concentration of the water. When reactor coolants are maintained under normal reducing conditions at high pH (5 to 10 cm 3 D 2 /kg D 2 O; 2 /kg D 2 O; pH > 10 with LiOD), Zircaloy cladding develops non-uniform, patch-type oxides. These patch-type oxides tend to coalesce with time to form a thick, uniform oxide layer after extended exposure. Under reducing coolant conditions, Zircaloy cladding absorbs less than 200 mg D/kg Zr (approximately 2.5 mg/dm 2 equivalent hydrogen) in about 500 days. With oxygen in the coolant, deuterium absorption is considerably less despite the significant increase in corrosion under such conditions

  7. Room temperature synthesis of heptazine-based microporous polymer networks as photocatalysts for hydrogen evolution.

    Science.gov (United States)

    Kailasam, Kamalakannan; Schmidt, Johannes; Bildirir, Hakan; Zhang, Guigang; Blechert, Siegfried; Wang, Xinchen; Thomas, Arne

    2013-06-25

    Two emerging material classes are combined in this work, namely polymeric carbon nitrides and microporous polymer networks. The former, polymeric carbon nitrides, are composed of amine-bridged heptazine moieties and showed interesting performance as a metal-free photocatalyst. These materials have, however, to be prepared at high temperatures, making control of their chemical structure difficult. The latter, microporous polymer networks have received increasing interest due to their high surface area, giving rise to interesting applications in gas storage or catalysis. Here, the central building block of carbon nitrides, a functionalized heptazine as monomer, and tecton are used to create microporous polymer networks. The resulting heptazine-based microporous polymers show high porosity, while their chemical structure resembles the ones of carbon nitrides. The polymers show activity for the photocatalytic production of hydrogen from water, even under visible light illumination. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Storage of hydrogen in advanced high pressure container. Appendices

    International Nuclear Information System (INIS)

    Bentzen, J.J.; Lystrup, A.

    2005-07-01

    The objective of the project has been to study barriers for a production of advanced high pressure containers especially suitable for hydrogen, in order to create a basis for a container production in Denmark. The project has primarily focused on future Danish need for hydrogen storage in the MWh area. One task has been to examine requirement specifications for pressure tanks that can be expected in connection with these stores. Six potential storage needs have been identified: (1) Buffer in connection with start-up/regulation on the power grid. (2) Hydrogen and oxygen production. (3) Buffer store in connection with VEnzin vision. (4) Storage tanks on hydrogen filling stations. (5) Hydrogen for the transport sector from 1 TWh surplus power. (6) Tanker transport of hydrogen. Requirements for pressure containers for the above mentioned use have been examined. The connection between stored energy amount, pressure and volume compared to liquid hydrogen and oil has been stated in tables. As starting point for production technological considerations and economic calculations of various container concepts, an estimation of laminate thickness in glass-fibre reinforced containers with different diameters and design print has been made, for a 'pure' fibre composite container and a metal/fibre composite container respectively. (BA)

  9. Temperature uniformity mapping in a high pressure high temperature reactor using a temperature sensitive indicator

    NARCIS (Netherlands)

    Grauwet, T.; Plancken, van der I.; Vervoort, L.; Matser, A.M.; Hendrickx, M.; Loey, van A.

    2011-01-01

    Recently, the first prototype ovomucoid-based pressure–temperature–time indicator (pTTI) for high pressure high temperature (HPHT) processing was described. However, for temperature uniformity mapping of high pressure (HP) vessels under HPHT sterilization conditions, this prototype needs to be

  10. Compatibility between vandium-base alloys and flowing lithium: Partitioning of hydrogen at elevated temperatures

    International Nuclear Information System (INIS)

    Hull, A.B.; Chopra, O.K.; Loomis, B.; Smith, D.

    1989-12-01

    A major concern in fusion reactor design is possible hydrogen-isotope-induced embrittlement of structural alloys in the neutron environment expected in these reactors. Hydrogen fractionation occurs between lithium and various refractory metals according to a temperature-dependent distribution coefficient, K H , that is defined as the ration of the hydrogen concentration in the metallic specimen to that in the liquid lithium. In the present work, K H was determined for pure vanadium and several binary and ternary alloys, and the commercial Vanstar 7. Hydrogen distribution studies were performed in an austenitic steel forced-circulation lithium loop. Equilibrium concentrations of hydrogen in vanadium-base alloys exposed to flowing lithium at temperatures of 350 to 550 degree C were measured by inert gas fusion techniques and residual gas analysis. Thermodynamic calculations are consistent with the effect of chromium and titanium in the alloys on the resultant hydrogen fractionation. Experimental and calculated results indicate that K H values are very low; i.e., the hydrogen concentrations in the lithium-equilibrated vanadium-base alloy specimens are about two orders of magnitude lower than those in the lithium. Because of this low distribution coefficient, embrittlement of vanadium alloys by hydrogen in lithium would not be expected. 15 refs., 5 figs., 4 tabs

  11. High Temperature Fluoride Salt Test Loop

    Energy Technology Data Exchange (ETDEWEB)

    Aaron, Adam M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Cunningham, Richard Burns [Univ. of Tennessee, Knoxville, TN (United States); Fugate, David L. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Holcomb, David Eugene [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Kisner, Roger A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Peretz, Fred J. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Robb, Kevin R. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Wilson, Dane F. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Yoder, Jr, Graydon L. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2015-12-01

    Effective high-temperature thermal energy exchange and delivery at temperatures over 600°C has the potential of significant impact by reducing both the capital and operating cost of energy conversion and transport systems. It is one of the key technologies necessary for efficient hydrogen production and could potentially enhance efficiencies of high-temperature solar systems. Today, there are no standard commercially available high-performance heat transfer fluids above 600°C. High pressures associated with water and gaseous coolants (such as helium) at elevated temperatures impose limiting design conditions for the materials in most energy systems. Liquid salts offer high-temperature capabilities at low vapor pressures, good heat transport properties, and reasonable costs and are therefore leading candidate fluids for next-generation energy production. Liquid-fluoride-salt-cooled, graphite-moderated reactors, referred to as Fluoride Salt Reactors (FHRs), are specifically designed to exploit the excellent heat transfer properties of liquid fluoride salts while maximizing their thermal efficiency and minimizing cost. The FHR s outstanding heat transfer properties, combined with its fully passive safety, make this reactor the most technologically desirable nuclear power reactor class for next-generation energy production. Multiple FHR designs are presently being considered. These range from the Pebble Bed Advanced High Temperature Reactor (PB-AHTR) [1] design originally developed by UC-Berkeley to the Small Advanced High-Temperature Reactor (SmAHTR) and the large scale FHR both being developed at ORNL [2]. The value of high-temperature, molten-salt-cooled reactors is also recognized internationally, and Czechoslovakia, France, India, and China all have salt-cooled reactor development under way. The liquid salt experiment presently being developed uses the PB-AHTR as its focus. One core design of the PB-AHTR features multiple 20 cm diameter, 3.2 m long fuel channels

  12. Hydrogen pumping and release by graphite under high flux plasma bombardment

    International Nuclear Information System (INIS)

    Hirooka, Y.; Leung, W.K.; Conn, R.W.; Goebel, D.M.; LaBombard, B.; Nygren, R.; Wilson, K.L.

    1988-01-01

    Inert gas (helium or argon) plasma bombardment has been found to increase the surface gas adsorptivity of isotropic graphite (POCO-graphite), which can then getter residual gases in a high vacuum system. The inert gas plasma bombardment was carried out at a flux ≅ 1 x 10 18 ions s -1 cm -2 to a fluence of the order of 10 21 ions/cm 2 and at temperatures around 800 0 C. The gettering capability of graphite can be easily recovered by repeating inert gas plasma bombardment. The activated graphite surface exhibits a smooth, sponge-like morphology with significantly increased pore openings, which correlates with the observed increase in the surface gas adsorptivity. The activated graphite surface has been observed to pump hydrogen plasma particles as well. From calibrated H-alpha measurements, the dynamic hydrogen retention capacity is evaluated to be as large as 2 x 10 18 H/cm 2 at temperatures below 100 0 C and at a plasma bombarding energy of 300 eV. The graphite temperature was varied between 15 and 480 0 C. Due to the plasma particle pumping capability, hydrogen recycling from the activated graphite surface is significantly reduced, relative to that from a pre-saturated surface. A pre-saturated surface was also observed to reproducibly pump a hydrogen plasma to a concentration of 9.5 x 10 17 H/cm 2 . The hydrogen retention capacity of graphite is found to decrease with increasing temperature. A transient pumping mechanism associated with the sponge-like surface morphology is conjectured to explain the large hydrogen retention capacity. Hydrogen release behavior under helium and argon plasma bombardment was also investigated, and the result indicated the possibility of some in-pore retrapping effect. 43 refs., 11 figs

  13. Study of the chemisorption and hydrogenation of propylene on platinum by temperature-programed desorption

    Energy Technology Data Exchange (ETDEWEB)

    Tsuchiya, S.; Nakamura, M.; Yoshioka, N.

    1978-01-01

    Temperature-programed desorption (TPD) chromotograms of propylene adsorbed on platinum black in the absence or presence of hydrogen preadsorbed, admitted simultaneously, or admitted later, all showed four peaks at about 260/sup 0/ (A), 380/sup 0/ (B), 570/sup 0/ (C), and higher than 720/sup 0/K (D). Peaks A and B were identified as mixtures of propylene and propane, and peaks C and D were methane formed by thermal decomposition of the chemisorbed propylene during desorption. When nitrogen rather than helium was used as the carrier gas for the TPD, only delta-hydrogen was observed; this suggested that propylene was more strongly adsorbed on the platinum than hydrogen. Studies of the reactivities with propylene of the various types of chemisorbed hydrogen previously detected by TPD showed that propylene reacted with ..gamma..-hydrogen present on the surface in the form of hydrogen atoms chemisorbed on top of platinum atoms and with ..beta..-hydrogen, molecular hydrogen chemisorbed in a bridged form, but did not react with delta-hydrogen. Tables and graph.

  14. Passivation of high temperature superconductors

    Science.gov (United States)

    Vasquez, Richard P. (Inventor)

    1991-01-01

    The surface of high temperature superconductors such as YBa2Cu3O(7-x) are passivated by reacting the native Y, Ba and Cu metal ions with an anion such as sulfate or oxalate to form a surface film that is impervious to water and has a solubility in water of no more than 10(exp -3) M. The passivating treatment is preferably conducted by immersing the surface in dilute aqueous acid solution since more soluble species dissolve into the solution. The treatment does not degrade the superconducting properties of the bulk material.

  15. CONFINEMENT OF HIGH TEMPERATURE PLASMA

    Science.gov (United States)

    Koenig, H.R.

    1963-05-01

    The confinement of a high temperature plasma in a stellarator in which the magnetic confinement has tended to shift the plasma from the center of the curved, U-shaped end loops is described. Magnetic means are provided for counteracting this tendency of the plasma to be shifted away from the center of the end loops, and in one embodiment this magnetic means is a longitudinally extending magnetic field such as is provided by two sets of parallel conductors bent to follow the U-shaped curvature of the end loops and energized oppositely on the inside and outside of this curvature. (AEC)

  16. US work on technical and economic aspects of electrolytic, thermochemical, and hybrid processes for hydrogen production at temperatures below 550 deg. C

    International Nuclear Information System (INIS)

    Petri, M.C.; Yyldyz, B.; Klickman, A.E.

    2006-01-01

    Hydrogen demand is increasing, but there are few options for affordable hydrogen production free of greenhouse gas emissions. Nuclear power is one of the most promising options. Most research is focused on high-temperature electrolytic and thermochemical processes for nuclear-generated hydrogen, but it will be many years before very high temperature reactors become commercially available. For light water reactors or supercritical reactors, low-temperature water electrolysis is a currently available technology for hydrogen production. Higher efficiencies may be gained through thermo-electrochemical hydrogen production cycles, but there are only a limited number that have heat requirements consistent with the lower temperatures of light-water reactor technology. Indeed, active research is ongoing for only three such cycles in the USA. Reductions in electricity and system costs would be needed (or the imposition of a carbon tax) for low-temperature water electrolysis to compete with today's costs for steam methane reformation. The interactions between hydrogen and electricity markets and hydrogen and electricity producers are complex and will evolve as the markets evolve. (author)

  17. Survey of high-temperature nuclear heat application

    International Nuclear Information System (INIS)

    Kirch, N.; Schaefer, M.

    1984-01-01

    Nuclear heat application at high temperatures can be divided into two areas - use of high-temperature steam up to 550 deg. C and use of high-temperature helium up to about 950 deg. C. Techniques of high-temperature steam and heat production and application are being developed in several IAEA Member States. In all these countries the use of steam for other than electricity production is still in a project definition phase. Plans are being discussed about using steam in chemical industries, oil refineries and for new synfuel producing plants. The use of nuclear generated steam for oil recovery from sands and shale is also being considered. High-temperature nuclear process heat production gives new possibilities for the application of nuclear energy - hard coals, lignites, heavy oils, fuels with problems concerning transport, handling and pollution can be converted into gaseous or liquid energy carriers with no loss of their energy contents. The main methods for this conversion are hydrogasification with hydrogen generated by nuclear heated steam reformers and steam gasification. These techniques will allow countries with large coal resources to replace an important part of their natural gas and oil consumption. Even countries with no fossil fuels can benefit from high-temperature nuclear heat - hydrogen production by thermochemical water splitting, nuclear steel making, ammonia production and the chemical heat-pipe system are examples in this direction. (author)

  18. Hydrogen permeability, diffusivity, and solubility of SUS 316L stainless steel in the temperature range 400 to 800 .deg. C for fusion reactor applications

    International Nuclear Information System (INIS)

    Lee, S. K.; Kim, H. S.; Noh, S. J.; Han, J. H.

    2011-01-01

    Tritium permeation is one of the critical issues for the economy and safety of fusion power plants. As an initial step in tritium permeation research for fusion reactor applications, experiments were initiated by using hydrogen as a tritium substitute. An experimental system for hydrogen permeation and related behaviors in solid materials was designed and constructed. A continuous flow method was adopted with a capacity for high temperatures up to ∼1,000 .deg. C under ultra-high vacuums of ∼10 -7 Pa. The hydrogen permeation behavior in SUS 316L stainless steel was investigated in the temperature range from 400 .deg. C to 800 .deg. C. As a result, the permeability, diffusivity and solubility of hydrogen were determined. The results were compared with the previously existing reference data. Changes in the sample's surface morphology after the hydrogen permeation experiment are also addressed.

  19. Water containing deuterium electrolysis to obtain gaseous hydrogen isotope in a high state of purity

    International Nuclear Information System (INIS)

    Bellanger, Gilbert

    1992-01-01

    In this paper, the basic concept is to prepare hydrogen in a high state of purity by electrolysing water using a palladium cathode. During electrolysis, hydrogen is at first adsorbed at the palladium surface, and next it diffuses through it till opposite face of its entry where it is desorbed; thus permitting to regain it in a very pure state for storage. The method can be used from water containing deuterium. To improve hydrogen adsorption, surface effect of palladium must be studied. It was found that heat treatment of palladium improved the hydrogen permeation flux. The diffusivity of hydrogen is controlled by Fick and Sieverts equations in which temperature has a significant influence on permeation rates. Anyway, hydrogen desorption does not cause any difficulty. In a second part, we have studied the isotopic separation factor using water containing deuterium. We remarked in fact that it depends on current density, overpotential, diffusivity of hydrogen and deuterium and isotopic composition of electrolyte as expected. In the last part, we realized an original electrolysis model in a glove-box in which are taken into account the results given before and also the technology components employed in processes involving the use of tritium. (author) [fr

  20. Site-Specific Hydrogen Isotope Composition of Propane: Mass spectrometric methods, equilibrium temperature dependence, and kinetics of exchange

    Science.gov (United States)

    Xie, H.; Ponton, C.; Kitchen, N.; Lloyd, M. K.; Lawson, M.; Formolo, M. J.; Eiler, J. M.

    2016-12-01

    Intramolecular isotope ordering can constrain temperatures of synthesis, mechanisms of formation, and/or source substrates of organic compounds. Here we explore site-specific hydrogen isotope variations of propane. Statistical thermodynamic models predict that at equilibrium methylene hydrogen (-CH2-) in propane will be 10's of per mil higher in D/H ratio than methyl hydrogen (-CH3) at geologically relevant temperatures, and that this difference is highly temperature dependent ( 0.5-1 ‰/°C). Chemical-kinetic controls on site-specific D/H in propane could constrain the mechanisms, conditions and extents of propane synthesis or destruction. We have developed a method for measuring the difference in D/H ratio between methylene and methyl hydrogen in propane by gas source mass spectrometry. The data were measured using the Thermo Fisher Double Focusing Sector high resolution mass spectrometer (DFS), and involve comparison of the D/H ratios of molecular ion (C3H8+) and the ethyl fragmental ion (C2H5+). We demonstrate the accuracy and precision of this method through analysis of D-labeled and independently analyzed propanes. In the exchange experiments, propane was heated (100-200 oC) either alone or in the presence of D-enriched water (δD=1,1419 ‰ SMOW), with or without one of several potentially catalytic substrates for hours to weeks. Propane was found to exchange hydrogen with water vigorously at 200 °C in the presence of metal catalysts. In the presence of Ni catalyst, methylene hydrogen exchanges 2.5 times faster than methyl hydrogen. Hydrogen exchange in the presence of Pd catalyst is more effective and can equilibrate hydrogen isotope distribution on propane on the order of 7 days. Isotopic exchange in the presence of natural materials have also been tested, but is only measurable in the methylene group at 200 °C. High catalytic activity of Pd permits attainment of a bracketed, time-invariant equilibrium state that we use to calibrate the site

  1. Preventing the embrittling by hydrogen when galvanizing high-grade steel

    Energy Technology Data Exchange (ETDEWEB)

    Paatsch, W.

    1987-09-01

    Galvanic precipitation of a double layer consisting of a dull nickel layer overlaid with a brilliant zinc layer on low-alloyed high-strength steel grades leads to the forming of zinc-nickel alloy layers during the subsequent heat treatment. According to traction tests carried out on high-strength steel grades, as well as to hydrogen permeability tests, this process prevents embrittling by hydrogen which might be caused by galvanic process sequences - and creates a diffusion block at the same time. The alloy layers have an excellent corrosion resistance and temperature stability.

  2. Modern high-temperature superconductivity

    International Nuclear Information System (INIS)

    Ching Wu Chu

    1988-01-01

    Ever since the discovery of superconductivity in 1911, its unusual scientific challenge and great technological potential have been recognized. For the past three-quarters of a century, superconductivity has done well on the science front. This is because sueprconductivity is interesting not only just in its own right but also in its ability to act as a probe to many exciting nonsuperconducting phenomena. For instance, it has continued to provide bases for vigorous activities in condensed matter science. Among the more recent examples are heavy-fermion systems and organic superconductors. During this same period of time, superconductivity has also performed admirably in the applied area. Many ideas have been conceived and tested, making use of the unique characteristics of superconductivity - zero resistivity, quantum interference phenomena, and the Meissner effect. In fact, it was not until late January 1987 that it became possible to achieve superconductivity with the mere use of liquid nitrogen - which is plentiful, cheap, efficient, and easy to handle - following the discovery of supercondictivity above 90 K in Y-Ba-Cu-O, the first genuine quaternary superconductor. Superconductivity above 90 K poses scientific and technological challenges not previously encountered: no existing theories can adequately describe superconductivity above 40 K and no known techniques can economically process the materials for full-scale applications. In this paper, therefore, the author recalls a few events leading to the discovery of the new class of quaternary compounds with a superconducting transition temperature T c in the 90 K range, describes the current experimental status of high-temperature superconductivity and, finally, discusses the prospect of very-high-temperature superconductivity, i.e., with a T c substantially higher than 100 K. 97 refs., 7 figs

  3. Studies of high temperature superconductors

    International Nuclear Information System (INIS)

    Narlikar, A.

    1989-01-01

    The high temperature superconductors (HTSCs) discovered are from the family of ceramic oxides. Their large scale utilization in electrical utilities and in microelectronic devices are the frontal challenges which can perhaps be effectively met only through consolidated efforts and expertise of a multidisciplinary nature. During the last two years the growth of the new field has occurred on an international scale and perhaps has been more rapid than in most other fields. There has been an extraordinary rush of data and results which are continually being published as short texts dispersed in many excellent journals, some of which were started to ensure rapid publication exclusively in this field. As a result, the literature on HTSCs has indeed become so massive and so diffuse that it is becoming increasingly difficult to keep abreast with the important and reliable facets of this fast-growing field. This provided the motivation to evolve a process whereby both professional investigators and students can have ready access to up-to- date in-depth accounts of major technical advances happening in this field. The present series Studies of High Temperature Superconductors has been launched to, at least in part, fulfill this need

  4. High temperature superconductor current leads

    International Nuclear Information System (INIS)

    Zeimetz, B.; Liu, H.K.; Dou, S.X.

    1996-01-01

    Full text: The use of superconductors in high electrical current applications (magnets, transformers, generators etc.) usually requires cooling with liquid Helium, which is very expensive. The superconductor itself produces no heat, and the design of Helium dewars is very advanced. Therefore most of the heat loss, i.e. Helium consumption, comes from the current lead which connects the superconductor with its power source at room temperature. The current lead usually consists of a pair of thick copper wires. The discovery of the High Temperature Superconductors makes it possible to replace a part of the copper with superconducting material. This drastically reduces the heat losses because a) the superconductor generates no resistive heat and b) it is a very poor thermal conductor compared with the copper. In this work silver-sheathed superconducting tapes are used as current lead components. The work comprises both the production of the tapes and the overall design of the leads, in order to a) maximize the current capacity ('critical current') of the superconductor, b) minimize the thermal conductivity of the silver clad, and c) optimize the cooling conditions

  5. Container floor at high temperatures

    International Nuclear Information System (INIS)

    Reutler, H.; Klapperich, H.J.; Mueller-Frank, U.

    1978-01-01

    The invention describes a floor for container which is stressed at high, changing temperatures and is intended for use in gas-cooled nuclear reactors. Due to the downward cooling gas flow in these types of reactor, the reactor floor is subjected to considerable dimensional changes during switching on and off. In the heating stage, the whole graphite structure of the reactor core and floor expands. In order to avoid arising constraining forces, sufficiently large expansion spaces must be allowed for furthermore restoring forces must be present to close the gaps again in the cooling phase. These restoring forces must be permanently present to prevent loosening of the core cuits amongst one another and thus uncontrollable relative movement. Spring elements are not suitable due to fast fatigue as a result of high temperatures and radiation exposure. It is suggested to have the floor elements supported on rollers whose rolling planes are downwards inclined to a fixed point for support. The construction is described in detail by means of drawings. (GL) [de

  6. Application of low-temperature plasma for the synthesis of hydrogenated graphene (graphane)

    Science.gov (United States)

    Shavelkina, M. B.; Amirov, R. H.; Katarzhis, V. A.; Kiselev, V. I.

    2017-12-01

    The possibility of a direct synthesis of hydrogenated graphene in decomposition of methane by means of low-temperature plasma was investigated. A DC plasma torch with an expanding channel-anode, a vortex gas supply and a self-setting arc length was used as a generator of low-temperature plasma. Argon was used as the plasma-forming gas. The temperatures of argon plasma and with methane addition to it were determined on the basis of spectral measurements. The synthesis products were characterized by electron microscopy and thermogravimetry. The effect of hydrogenated graphene as a nanomodifier on the properties of the cubic boron nitride based functional ceramics was investigated.

  7. Syntrophic interactions drive the hydrogen production from glucose at low temperature in microbial electrolysis cells

    KAUST Repository

    Lu, Lu; Xing, Defeng; Ren, Nanqi; Logan, Bruce E.

    2012-01-01

    H2 can be obtained from glucose by fermentation at mesophilic temperatures, but here we demonstrate that hydrogen can also be obtained from glucose at low temperatures using microbial electrolysis cells (MECs). H2 was produced from glucose at 4°C

  8. Temperature suppression of STM-induced desorption of hydrogen on Si(100) surfaces

    DEFF Research Database (Denmark)

    Thirstrup, C.; Sakurai, M.; Nakayama, T.

    1999-01-01

    The temperature dependence of hydrogen (H) desorption from Si(100) H-terminated surfaces by a scanning tunneling microscope (STM) is reported for negative sample bias. It is found that the STM induced H desorption rate (R) decreases several orders of magnitude when the substrate temperature...

  9. High Temperature Radio Frequency Loads

    CERN Document Server

    Federmann, S; Grudiev, A; Montesinos, E; Syratchev, I

    2011-01-01

    In the context of energy saving and recovery requirements the design of reliable and robust RF power loads which permit a high outlet temperature and high pressure of the cooling water is desirable. Cooling water arriving at the outlet withmore than 150 ◦C and high pressure has a higher value than water with 50 ◦C under low pressure. Conventional RF power loads containing dielectric and magnetic materials as well as sensitive ceramic windows usually do not permit going much higher than 90 ◦C. Here we present and discuss several design concepts for "metal only" RF high power loads. One concept is the application of magnetic steel corrugated waveguides near cutoff – this concept could find practical use above several GHz. Another solution are resonant structures made of steel to be installed in large waveguides for frequencies of 500 MHz or lower. Similar resonant structures above 100 MHz taking advantage of the rather high losses of normal steel may also be used in coaxial line geometries with large di...

  10. Renewable carbohydrates are a potential high-density hydrogen carrier

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Y.-H. Percival [Biological Systems Engineering Department, 210-A Seitz Hall, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061 (United States); Institute for Critical Technology and Applied Sciences (ICTAS), Virginia Polytechnic Institute and State University, Blacksburg, VA 24061 (United States); DOE BioEnergy Science Center (BESC), Oak Ridge, TN 37831 (United States)

    2010-10-15

    The possibility of using renewable biomass carbohydrates as a potential high-density hydrogen carrier is discussed here. Gravimetric density of polysaccharides is 14.8 H{sub 2} mass% where water can be recycled from PEM fuel cells or 8.33% H{sub 2} mass% without water recycling; volumetric densities of polysaccharides are >100 kg of H{sup 2}/m{sup 3}. Renewable carbohydrates (e.g., cellulosic materials and starch) are less expensive based on GJ than are other hydrogen carriers, such as hydrocarbons, biodiesel, methanol, ethanol, and ammonia. Biotransformation of carbohydrates to hydrogen by cell-free synthetic (enzymatic) pathway biotransformation (SyPaB) has numerous advantages, such as high product yield (12 H{sub 2}/glucose unit), 100% selectivity, high energy conversion efficiency (122%, based on combustion energy), high-purity hydrogen generated, mild reaction conditions, low-cost of bioreactor, few safety concerns, and nearly no toxicity hazards. Although SyPaB may suffer from current low reaction rates, numerous approaches for accelerating hydrogen production rates are proposed and discussed. Potential applications of carbohydrate-based hydrogen/electricity generation would include hydrogen bioreactors, home-size electricity generators, sugar batteries for portable electronics, sugar-powered passenger vehicles, and so on. Developments in thermostable enzymes as standardized building blocks for cell-free SyPaB projects, use of stable and low-cost biomimetic NAD cofactors, and accelerating reaction rates are among the top research and development priorities. International collaborations are urgently needed to solve the above obstacles within a short time. (author)

  11. Optimization of the Neutronics of the Advanced High Temperature Reactor

    International Nuclear Information System (INIS)

    Zakova, Jitka; Talamo, Alberto

    2006-01-01

    In these studies, we have investigated the neutronic and safety performance of the Advanced High Temperature Reactor (AHTR) for plutonium and uranium fuels and we extended the analysis to five different coolants. The AHTR is a graphite-moderated and molten salt-cooled high temperature reactor, which takes advantage of the TRISO particles technology for the fuel utilization. The conceptual design of the core, proposed at the Oak Ridge National Laboratory, aims to provide an alternative to helium as coolant of high-temperature reactors for industrial applications like hydrogen production. We evaluated the influence of the radial reflector on the criticality of the core for the uranium and plutonium fuels and we focused on the void coefficient of 5 different molten salts; since the safety of the reactor is enhanced also by the large and negative coefficient of temperature, we completed our investigation by observing the keff changes when the graphite temperature varies from 300 to 1800 K. (authors)

  12. Preliminary study on high temperature heat exchanger for nuclear steel making

    Energy Technology Data Exchange (ETDEWEB)

    Mori, Y [Tokyo Inst. of Tech. (Japan); Ikegami, H

    1975-03-01

    In the high temperature heat exchanger as well as the steam reformer, several technical problems should be solved before realizing a nuclear plant complex for iron and steel making. Research has been carried out on heat exchanger between helium and steam, hydrogen permeation through super alloys, hydrogen removal using a titanium sponge, and creep and carburization performance of super alloys. The primary coolant used is helium having a pressure of approximately 12 kg/cm/sup 2/G and a temperature of approximately 1100/sup 0/C measured at the inlet of the high temperature heat exchanger, i.e., the test section. Steam, hydrogen and carbon monoxide are used as secondary coolants.

  13. High Temperature and Pressure Alkaline Electrolysis

    DEFF Research Database (Denmark)

    Allebrod, Frank

    against conventional technologies for hydrogen production, such as natural gas reforming, the production and investment costs have to be reduced. A reduction of the investment costs may be achieved by increasing the operational pressure and temperature of the electrolyzer, as this will result in: 1.......3 A cm-2 combined with relatively small production costs may lead to both reduced investment and operating costs for hydrogen and oxygen production. One of the produced electrolysis cells was operated for 350 h. Based on the successful results a patent application covering this novel cell was filed...

  14. System efficiency for two-step metal oxide solar thermochemical hydrogen production – Part 2: Impact of gas heat recuperation and separation temperatures

    KAUST Repository

    Ehrhart, Brian D.

    2016-09-22

    The solar-to-hydrogen (STH) efficiency is calculated for various operating conditions for a two-step metal oxide solar thermochemical hydrogen production cycle using cerium(IV) oxide. An inert sweep gas was considered as the O2 removal method. Gas and solid heat recuperation effectiveness values were varied between 0 and 100% in order to determine the limits of the effect of these parameters. The temperature at which the inert gas is separated from oxygen for an open-loop and recycled system is varied. The hydrogen and water separation temperature was also varied and the effect on STH efficiency quantified. This study shows that gas heat recuperation is critical for high efficiency cycles, especially at conditions that require high steam and inert gas flowrates. A key area for future study is identified to be the development of ceramic heat exchangers for high temperature gas-gas heat exchange. Solid heat recuperation is more important at lower oxidation temperatures that favor temperature-swing redox processing, and the relative impact of this heat recuperation is muted if the heat can be used elsewhere in the system. A high separation temperature for the recycled inert gas has been shown to be beneficial, especially for cases of lower gas heat recuperation and increased inert gas flowrates. A higher water/hydrogen separation temperature is beneficial for most gas heat recuperation effectiveness values, though the overall impact on optimal system efficiency is relatively small for the values considered. © 2016 Hydrogen Energy Publications LLC.

  15. The permeation of hydrogen in a steel at elevated temperature by an electrochemical method

    International Nuclear Information System (INIS)

    Tsubakino, H.; Ando, A.; Yamakawa, K.

    1984-01-01

    An electrochemical permeation method has been widely used to study the transport characteristics of hydrogen in metals, i.e., the content, diffusivity and permeability. This electrochemical measurement technique has the following remarkable features: a good detection limit for the measurement of hydrogen content, a simpler measuring apparatus, suitability for successive measurement of the transport characteristics, and flexibility in variation of experimental conditions. However this method has been restricted to temperatures below 373 K because an aqueous solution has been used as an electrode. In this study, an electrochemical permeation method using molten salts at elevated temperatures (673-773 K) in the range of practical interest for hydrogen attack in steel is presented. The introduction of hydrogen by use of molten salts has been reported but it has been performed at 423473 K and at 553 K

  16. High temperature combustion facility: present capabilities and future prospects

    International Nuclear Information System (INIS)

    Boccio, J.L.; Ginsberg, T.; Ciccarelli, G.

    1995-01-01

    The high-temperature combustion facility constructed and operated by the Department of Advanced Technology of Brookhaven National Laboratory to support and promote research in the area of hydrogen combustion phenomena in mixtures prototypical to light-water reactor containment atmospheres under potential severe accident conditions is reported. The facility can accommodate combustion research activities encompassing the fields of detonation physics, flame acceleration, and low-speed deflagration in a wide range of combustible gas mixtures at initial temperatures up to 700 K and post-combustion pressures up to 100 atmospheres. Some preliminary test results are presented that provide further evidence that the effect of temperature is to increase the sensitivity of hydrogen-air-steam mixtures to undergo detonation [ru

  17. High concentration agglomerate dynamics at high temperatures.

    Science.gov (United States)

    Heine, M C; Pratsinis, S E

    2006-11-21

    The dynamics of agglomerate aerosols are investigated at high solids concentrations that are typical in industrial scale manufacture of fine particles (precursor mole fraction larger than 10 mol %). In particular, formation and growth of fumed silica at such concentrations by chemical reaction, coagulation, and sintering is simulated at nonisothermal conditions and compared to limited experimental data and commercial product specifications. Using recent chemical kinetics for silica formation by SiCl4 hydrolysis and neglecting aerosol polydispersity, the evolution of the diameter of primary particles (specific surface area, SSA), hard- and soft-agglomerates, along with agglomerate effective volume fraction (volume occupied by agglomerate) is investigated. Classic Smoluchowski theory is fundamentally limited for description of soft-agglomerate Brownian coagulation at high solids concentrations. In fact, these high concentrations affect little the primary particle diameter (or SSA) but dominate the soft-agglomerate diameter, structure, and volume fraction, leading to gelation consistent with experimental data. This indicates that restructuring and fragmentation should affect product particle characteristics during high-temperature synthesis of nanostructured particles at high concentrations in aerosol flow reactors.

  18. Pressure of a partially ionized hydrogen gas : numerical results from exact low temperature expansions

    OpenAIRE

    Alastuey , Angel; Ballenegger , Vincent

    2010-01-01

    8 pages; International audience; We consider a partially ionized hydrogen gas at low densities, where it reduces almost to an ideal mixture made with hydrogen atoms in their ground-state, ionized protons and ionized electrons. By performing systematic low-temperature expansions within the physical picture, in which the system is described as a quantum electron-proton plasma interacting via the Coulomb potential, exact formulae for the first five leading corrections to the ideal Saha equation ...

  19. The self limiting effect of hydrogen cluster in gas jet under liquid nitrogen temperature

    International Nuclear Information System (INIS)

    Han Jifeng; Yang Chaowen; Miao Jingwei; Fu Pengtao; Luo Xiaobing; Shi Miangong

    2010-01-01

    The generation of hydrogen clusters in gas jet is tested using the Rayleigh scattering method under liquid nitrogen temperature of 79 K. The self limiting effect of hydrogen cluster is studied and it is found that the cluster formation is greatly affected by the number of expanded molecules. The well designed liquid nitrogen cold trap ensured that the hydrogen cluster would keep maximum size for maximum 15 ms during one gas jet. The scattered light intensity exhibits a power scaling on the backing pressure ranging from 5 to 48 bar with the power value of 4.1.

  20. UO{sub 2} surface oxidation by mixtures of water vapor and hydrogen as a function of temperature

    Energy Technology Data Exchange (ETDEWEB)

    Espriu-Gascon, A., E-mail: alexandra.espriu@upc.edu [Department of Chemical Engineering, Universitat Politècnica Catalunya-Barcelona Tech, Diagonal 647, E-08028 Barcelona (Spain); Llorca, J.; Domínguez, M. [Institut de Tècniques Energètiques (INTE), Universitat Politècnica Catalunya-Barcelona Tech, Diagonal 647, E-08028 Barcelona (Spain); Centre for Research in NanoEngineering (CRNE), Universitat Politècnica Catalunya-Barcelona Tech, Diagonal 647, E-08028 Barcelona (Spain); Giménez, J.; Casas, I. [Department of Chemical Engineering, Universitat Politècnica Catalunya-Barcelona Tech, Diagonal 647, E-08028 Barcelona (Spain); Pablo, J. de [Department of Chemical Engineering, Universitat Politècnica Catalunya-Barcelona Tech, Diagonal 647, E-08028 Barcelona (Spain); Fundació CTM Centre Tecnològic, Plaça de la Ciència 2, E-08243 Manresa (Spain)

    2015-12-15

    In the present work, X-Ray Photoelectron Spectroscopy (XPS) was used to study the effect of water vapor on the UO{sub 2} surface as a function of temperature. The experiments were performed in situ inside a high pressure chamber attached to the XPS instrument. UO{sub 2} samples were put in contact with either hydrogen or argon streams, saturated with water at room temperature, and the sample surface evolution was analyzed by XPS. In the case of the water vapor/argon experiments, one experiment at 350 °C was performed and, in the case of the water vapor/hydrogen experiments, the temperatures used inside the reactor were 60, 120, 200 and 350 °C. On one hand, in presence of argon, the results obtained showed that the water vapor in the argon stream oxidized 93% of the U(IV) in the sample surface. On the other hand, the degree of UO{sub 2} surface oxidation showed a different dependence on the temperature in the experiments performed in the presence of hydrogen: the maximum surface oxidation occurred at 120 °C, where 65.4% of U(IV) in the sample surface was oxidized, while at higher temperatures, the surface oxidation decreased. This observation is attributed to the increase of hydrogen reducing effect when temperature increases which prevents part of the oxidation of the UO{sub 2} surface by the water vapor. - Highlights: • UO{sub 2} surface has been oxidized by water vapor in an argon stream at 350 °C. • H{sub 2} reduced more uranium oxidation produced by water at 350 °C when compared to Ar. • In H{sub 2} presence, the uranium oxidation produced by water depends on the temperature.

  1. Ion temperature profiles along a hydrogen diagnostic beam in a TORE SUPRA tokamak plasma

    International Nuclear Information System (INIS)

    Romannikov, A.; Petrov, Yu.; Platts, P.; Khess, V.; Khutter, T.; Farzhon, Zh.; Moro, F.

    2002-01-01

    By means of corpuscular diagnostics one studies temperature of ions along a diagnostic hydrogen beam. Paper presents comparison of temperature of plasma (deuterium) basic ions measures by means of the active corpuscular diagnostics with temperature of C + carbon ions along a beam. One studies behavior peculiarities of T i ion temperature profiles for TORE-SUPRA different modes, such as: formation of plane and even hollow T i profiles for ohmic modes, variation of T i profiles under operation of an ergodic diverter, difference of temperature of basic ions measured by means of the active corpuscular diagnostics from C +5 temperature. Paper offers clear explanation of these peculiarities [ru

  2. Why is magnesium diboride's superconducting temperature increased by the hydrogenation process?

    International Nuclear Information System (INIS)

    Flaumbaum, V.V.; Russell, G.J.; Stewart, G.A.

    2002-01-01

    Full text: This work demonstrates that the superconducting transition temperature for MgB 2 can be increased significantly by the hydrogenation process. A preliminary electronic report has already been placed on the archival web site http://au.arXiv.org/with reference number cond-mat/0112301. Given that there appears not to be a large enough interstitial site to accommodate the hydrogen, it is not yet clear what mechanism is involved. The justification for attempting hydrogenation was that metallic Pd becomes a superconductor when it is hydrogenated. We exposed MgB 2 powder to pure hydrogen gas in a stainless steel chamber and heated it. Before removing the specimen, the chamber was cooled in liquid N 2 and opened to air. This was an attempt to 'poison' the specimen's surface. The T c , determined using ac susceptibility, was found to increased for all hydrogenated specimens. The largest increase achieved so far is AT C ∼1.25 K for a specimen hydrogenated under 10 atm H 2 at 600 deg C for 2 hours (H/MgB 2 ∼ 0.03). However, the optimum conditions are yet to be determined. A further complication is that a similar effect (albeit smaller) is obtained by subjecting the MgB 2 to the same process but with helium or argon gas instead of hydrogen

  3. High Temperature Superconductor Accelerator Magnets

    CERN Document Server

    AUTHOR|(CDS)2079328; de Rijk, Gijs; Dhalle, Marc

    2016-11-10

    For future particle accelerators bending dipoles are considered with magnetic fields exceeding $20T$. This can only be achieved using high temperature superconductors (HTS). These exhibit different properties from classical low temperature superconductors and still require significant research and development before they can be applied in a practical accelerator magnet. In order to study HTS in detail, a five tesla demonstrator magnet named Feather-M2 is designed and constructed. The magnet is based on ReBCO coated conductor, which is assembled into a $10kA$ class Roebel cable. A new and optimized Aligned Block layout is used, which takes advantage of the anisotropy of the conductor. This is achieved by providing local alignment of the Roebel cable in the coil windings with the magnetic field lines. A new Network Model capable of analyzing transient electro-magnetic and thermal phenomena in coated conductor cables and coils is developed. This model is necessary to solve critical issues in coated conductor ac...

  4. Low temperature catalytic combustion of natural gas - hydrogen - air mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Newson, E; Roth, F von; Hottinger, P; Truong, T B [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1999-08-01

    The low temperature catalytic combustion of natural gas - air mixtures would allow the development of no-NO{sub x} burners for heating and power applications. Using commercially available catalysts, the room temperature ignition of methane-propane-air mixtures has been shown in laboratory reactors with combustion efficiencies over 95% and maximum temperatures less than 700{sup o}C. After a 500 hour stability test, severe deactivation of both methane and propane oxidation functions was observed. In cooperation with industrial partners, scaleup to 3 kW is being investigated together with startup dynamics and catalyst stability. (author) 3 figs., 3 refs.

  5. The high-temperature reactor

    International Nuclear Information System (INIS)

    Kirchner, U.

    1991-01-01

    The book deals with the development of the German high-temperature reactor (pebble-bed), the design of a prototype plant and its (at least provisional) shut-down in 1989. While there is a lot of material on the HTR's competitor, the fast breeder, literature is very incomplete on HTRs. The author describes HTR's history as a development which was characterised by structural divergencies but not effectively steered and monitored. There was no project-oriented 'community' such as there was for the fast breeder. Also, the new technology was difficult to control there were situations where no one quite knew what was going on. The technical conditions however were not taken as facts but as a basis for interpretation, wishes and reservations. The HTR gives an opportunity to consider the conditions under which large technical projects can be carried out today. (orig.) [de

  6. High temperature industrial heat pumps

    Energy Technology Data Exchange (ETDEWEB)

    Berghmans, J. (Louvain Univ., Heverlee (Belgium). Inst. Mechanica)

    1990-01-01

    The present report intends to describe the state of the art of high temperature industrial heat pumps. A description is given of present systems on the market. In addition the research and development efforts on this subject are described. Compression (open as well as closed cycle) systems, as well as absorption heat pumps (including transformers), are considered. This state of the art description is based upon literature studies performed by a team of researchers from the Katholieke Universiteit Leuven, Belgium. The research team also analysed the economics of heat pumps of different types under the present economic conditions. The heat pumps are compared with conventional heating systems. This analysis was performed in order to evaluate the present condition of the heat pump in the European industry.

  7. Faraday imaging at high temperatures

    Science.gov (United States)

    Hackel, Lloyd A.; Reichert, Patrick

    1997-01-01

    A Faraday filter rejects background light from self-luminous thermal objects, but transmits laser light at the passband wavelength, thus providing an ultra-narrow optical bandpass filter. The filter preserves images so a camera looking through a Faraday filter at a hot target illuminated by a laser will not see the thermal radiation but will see the laser radiation. Faraday filters are useful for monitoring or inspecting the uranium separator chamber in an atomic vapor laser isotope separation process. Other uses include viewing welds, furnaces, plasma jets, combustion chambers, and other high temperature objects. These filters are can be produced at many discrete wavelengths. A Faraday filter consists of a pair of crossed polarizers on either side of a heated vapor cell mounted inside a solenoid.

  8. Faraday imaging at high temperatures

    International Nuclear Information System (INIS)

    Hackel, L.A.; Reichert, P.

    1997-01-01

    A Faraday filter rejects background light from self-luminous thermal objects, but transmits laser light at the passband wavelength, thus providing an ultra-narrow optical bandpass filter. The filter preserves images so a camera looking through a Faraday filter at a hot target illuminated by a laser will not see the thermal radiation but will see the laser radiation. Faraday filters are useful for monitoring or inspecting the uranium separator chamber in an atomic vapor laser isotope separation process. Other uses include viewing welds, furnaces, plasma jets, combustion chambers, and other high temperature objects. These filters are can be produced at many discrete wavelengths. A Faraday filter consists of a pair of crossed polarizers on either side of a heated vapor cell mounted inside a solenoid. 3 figs

  9. Mapping temperature-induced conformational changes in the Escherichia coli heat shock transcription factor sigma 32 by amide hydrogen exchange

    DEFF Research Database (Denmark)

    Rist, Wolfgang; Jørgensen, Thomas J D; Roepstorff, Peter

    2003-01-01

    Stress conditions such as heat shock alter the transcriptional profile in all organisms. In Escherichia coli the heat shock transcription factor, sigma 32, out-competes upon temperature up-shift the housekeeping sigma-factor, sigma 70, for binding to core RNA polymerase and initiates heat shock...... gene transcription. To investigate possible heat-induced conformational changes in sigma 32 we performed amide hydrogen (H/D) exchange experiments under optimal growth and heat shock conditions combined with mass spectrometry. We found a rapid exchange of around 220 of the 294 amide hydrogens at 37...... degrees C, indicating that sigma 32 adopts a highly flexible structure. At 42 degrees C we observed a slow correlated exchange of 30 additional amide hydrogens and localized it to a helix-loop-helix motif within domain sigma 2 that is responsible for the recognition of the -10 region in heat shock...

  10. Modelling of hydrogen permeability of membranes for high-purity hydrogen production

    Science.gov (United States)

    Zaika, Yury V.; Rodchenkova, Natalia I.

    2017-11-01

    High-purity hydrogen is required for clean energy and a variety of chemical technology processes. Different alloys, which may be well-suited for use in gas-separation plants, were investigated by measuring specific hydrogen permeability. One had to estimate the parameters of diffusion and sorption to numerically model the different scenarios and experimental conditions of the material usage (including extreme ones), and identify the limiting factors. This paper presents a nonlinear mathematical model taking into account the dynamics of sorption-desorption processes and reversible capture of diffusing hydrogen by inhomogeneity of the material’s structure, and also modification of the model when the transport rate is high. The results of numerical modelling allow to obtain information about output data sensitivity with respect to variations of the material’s hydrogen permeability parameters. Furthermore, it is possible to analyze the dynamics of concentrations and fluxes that cannot be measured directly. Experimental data for Ta77Nb23 and V85Ni15 alloys were used to test the model. This work is supported by the Russian Foundation for Basic Research (Project No. 15-01-00744).

  11. Materials for High-Temperature Catalytic Combustion

    Energy Technology Data Exchange (ETDEWEB)

    Ersson, Anders

    2003-04-01

    Catalytic combustion is an environmentally friendly technique to combust fuels in e.g. gas turbines. Introducing a catalyst into the combustion chamber of a gas turbine allows combustion outside the normal flammability limits. Hence, the adiabatic flame temperature may be lowered below the threshold temperature for thermal NO{sub X} formation while maintaining a stable combustion. However, several challenges are connected to the application of catalytic combustion in gas turbines. The first part of this thesis reviews the use of catalytic combustion in gas turbines. The influence of the fuel has been studied and compared over different catalyst materials. The material section is divided into two parts. The first concerns bimetallic palladium catalysts. These catalysts showed a more stable activity compared to their pure palladium counterparts for methane combustion. This was verified both by using an annular reactor at ambient pressure and a pilot-scale reactor at elevated pressures and flows closely resembling the ones found in a gas turbine combustor. The second part concerns high-temperature materials, which may be used either as active or washcoat materials. A novel group of materials for catalysis, i.e. garnets, has been synthesised and tested in combustion of methane, a low-heating value gas and diesel fuel. The garnets showed some interesting abilities especially for combustion of low-heating value, LHV, gas. Two other materials were also studied, i.e. spinels and hexa aluminates, both showed very promising thermal stability and the substituted hexa aluminates also showed a good catalytic activity. Finally, deactivation of the catalyst materials was studied. In this part the sulphur poisoning of palladium, platinum and the above-mentioned complex metal oxides has been studied for combustion of a LHV gas. Platinum and surprisingly the garnet were least deactivated. Palladium was severely affected for methane combustion while the other washcoat materials were

  12. Improved controlled atmosphere high temperature scanning probe microscope

    DEFF Research Database (Denmark)

    Hansen, Karin Vels; Wu, Yuehua; Jacobsen, Torben

    2013-01-01

    fuel cells and electrolyzer cells. Here, we report on advanced improvements of our original controlled atmosphere high temperature scanning probe microscope, CAHT-SPM. The new microscope can employ a broad range of the scanning probe techniques including tapping mode, scanning tunneling microscopy......, scanning tunneling spectroscopy, conductive atomic force microscopy, and Kelvin probe force microscopy. The temperature of the sample can be as high as 850 °C. Both reducing and oxidizing gases such as oxygen, hydrogen, and nitrogen can be added in the sample chamber and the oxygen partial pressure (pO2...

  13. High temperature incineration. Densification of granules from high temperature incineration

    International Nuclear Information System (INIS)

    Voorde, N. van de; Claes, J.; Taeymans, A.; Hennart, D.; Gijbels, J.; Balleux, W.; Geenen, G.; Vangeel, J.

    1982-01-01

    The incineration system of radioactive waste discussed in this report, is an ''integral'' system, which directly transforms a definite mixture of burnable and unburnable radioactive waste in a final product with a sufficient insolubility to be safely disposed of. At the same time, a significant volume reduction occurs by this treatment. The essential part of the system is a high temperature incinerator. The construction of this oven started in 1974, and while different tests with simulated inactive or very low-level active waste were carried out, the whole system was progressively and continuously extended and adapted, ending finally in an installation with completely remote control, enclosed in an alpha-tight room. In this report, a whole description of the plant and of its auxiliary installations will be given; then the already gained experimental results will be summarized. Finally, the planning for industrial operation will be briefly outlined. An extended test with radioactive waste, which was carried out in March 1981, will be discussed in the appendix

  14. Sensitization of erbium in silicon-rich silica : the effect of annealing temperature and hydrogen passivation

    International Nuclear Information System (INIS)

    Wilkinson, A.R.; Forcales, M.; Elliman, R.G.

    2005-01-01

    This paper reports on the effect of annealing temperature and hydrogen passivation on the excitation cross-section and photoluminescence of erbium in silicon-rich silica. Samples were prepared by co-implantation of Si and Er into SiO 2 followed by a single thermal anneal at temperatures ranging from 800 to 1100 degrees C, and with or without hydrogen passivation performed at 500 degrees C. Using time-resolved photoluminescence, the effective erbium excitation cross-section is shown to increase by a factor 3, while the number of optically active erbium ions decreases by a factor of 4 with increasing annealing temperature. Hydrogen passivation is shown to increase the luminescence intensity and to shorten the luminescence lifetime at 1.54 μm only in the presence of Si nanocrystals. The implications fo these results for realizing a silicon-based optical amplifier are also discussed. (author). 19 refs., 3 figs

  15. Hydrogen-induced high damping of bulk metallic glasses

    International Nuclear Information System (INIS)

    Hasegawa, M.

    2009-01-01

    There are two important topics concerned with the recent researches on the damping materials of hydrogenated metallic glasses (HMGs). One is the mechanism of the high hydrogen-induced internal friction of HMGs. The other is the materials processing of 'bulk' HMGs for engineering. This article describes the summary of our recent studies on these topics. The first one is closely related to the local structure of the metallic glasses. Therefore, our recent results on the intermediate-range local structure of the simple two Zr-based metallic glasses are described, which has been clarified by the Voronoi analysis using the experimental data of the neutron diffraction measurements. The hydrogen-induced internal friction of HMGs is also discussed on the basis of these recent results of the local structure of the metallic glasses. In terms of the second topic, the first successful preparation of heavily hydrogenated Zr-based bulk HMG rods without hydrogen-induced surface embrittlement is described. They are prepared by a powder-compact-melting and liquid-casting process using Zr-Al-Ni-Cu metallic glass and ZrH 2 powders as the starting materials. It has been found that they have high damping properties.

  16. Secret high-temperature reactor concept for inertial fusion

    International Nuclear Information System (INIS)

    Monsler, M.J.; Meier, W.R.

    1983-01-01

    The goal of our SCEPTRE project was to create an advanced second-generation inertial fusion reactor that offers the potential for either of the following: (1) generating electricity at 50% efficiency, (2) providing high temperature heat (850 0 C) for hydrogen production, or (3) producing fissile fuel for light-water reactors. We have found that these applications are conceptually feasible with a reactor that is intrinsically free of the hazards of catastrophic fire or tritium release

  17. Active Edge Sites Engineering in Nickel Cobalt Selenide Solid Solutions for Highly Efficient Hydrogen Evolution

    KAUST Repository

    Xia, Chuan; Liang, Hanfeng; Zhu, Jiajie; Schwingenschlö gl, Udo; Alshareef, Husam N.

    2017-01-01

    free energy for atomic hydrogen adsorption in NiCoSe, identified by temperature-dependent conductivities and density functional theory calculations, the authors have achieved unprecedented fast hydrogen evolution kinetics, approaching that of Pt

  18. Interplay of community dynamics, temperature, and productivity on the hydrogen isotope signatures of lipid biomarkers

    Directory of Open Access Journals (Sweden)

    S. N. Ladd

    2017-09-01

    spring, which are displaced by more 2H-depleted fatty acids as phytoplankton productivity increases. Smaller increases in 2H discrimination for phytol and brassicasterol suggest that a portion of the signal is due to changes in net photoautotrophic 2H fractionation, which may be caused by increasing temperatures, a shift from maintenance to high growth, or changes in the community assemblage. The fractionation factors for brassicasterol were significantly different between the two lakes, suggesting that its hydrogen isotope composition may be more sensitive to nutrient regime than is the case for fatty acids or phytol.

  19. The reaction of hydrogen atoms with hydrogen peroxide as a function of temperature

    DEFF Research Database (Denmark)

    Lundström, T.; Christensen, H.; Sehested, K.

    2001-01-01

    The temperature dependence for the reaction of H atoms with H2O2 at pH 1 has been determined using pulse radiolysis technique. The reaction was studied in the temperature range 10-120 degreesC. The rate constant at 25 degreesC was found to be 5.1 +/- 0.5 x 10(7) dm(3) mol(-1) s(-1) and the activa......The temperature dependence for the reaction of H atoms with H2O2 at pH 1 has been determined using pulse radiolysis technique. The reaction was studied in the temperature range 10-120 degreesC. The rate constant at 25 degreesC was found to be 5.1 +/- 0.5 x 10(7) dm(3) mol(-1) s(-1...

  20. New insights into designing metallacarborane based room temperature hydrogen storage media.

    Science.gov (United States)

    Bora, Pankaj Lochan; Singh, Abhishek K

    2013-10-28

    Metallacarboranes are promising towards realizing room temperature hydrogen storage media because of the presence of both transition metal and carbon atoms. In metallacarborane clusters, the transition metal adsorbs hydrogen molecules and carbon can link these clusters to form metal organic framework, which can serve as a complete storage medium. Using first principles density functional calculations, we chalk out the underlying principles of designing an efficient metallacarborane based hydrogen storage media. The storage capacity of hydrogen depends upon the number of available transition metal d-orbitals, number of carbons, and dopant atoms in the cluster. These factors control the amount of charge transfer from metal to the cluster, thereby affecting the number of adsorbed hydrogen molecules. This correlation between the charge transfer and storage capacity is general in nature, and can be applied to designing efficient hydrogen storage systems. Following this strategy, a search for the best metallacarborane was carried out in which Sc based monocarborane was found to be the most promising H2 sorbent material with a 9 wt.% of reversible storage at ambient pressure and temperature.

  1. Non-combustible nuclear radiation shields with high hydrogen content

    International Nuclear Information System (INIS)

    Hall, W.C.; Peterson, J.M.

    1978-01-01

    The invention relates to compositions, methods of production, and uses of non-combustible nuclear radiation shields, with particular emphasis on those containing a high concentration of hydrogen atoms, especially effective for moderating neutron energy by elastic scatter, dispersed as a discontinuous phase in a continuous phase of a fire resistant matrix

  2. Hydrogen-rich gas production from waste plastics by pyrolysis and low-temperature steam reforming over a ruthenium catalyst

    International Nuclear Information System (INIS)

    Namioka, Tomoaki; Saito, Atsushi; Inoue, Yukiharu; Park, Yeongsu; Min, Tai-jin; Roh, Seon-ah; Yoshikawa, Kunio

    2011-01-01

    Operating conditions for low-temperature pyrolysis and steam reforming of plastics over a ruthenium catalyst were investigated. In the range studied, the highest gas and lowest coke fractions for polystyrene (PS) with a 60 g h -1 scale, continuous-feed, two-stage gasifier were obtained with a pyrolyzer temperature of 673 K, steam reforming temperature of 903 K, and weight hourly space velocity (WHSV) of 0.10 g-sample g-catalyst -1 h -1 . These operating conditions are consistent with optimum conditions reported previously for polypropylene. Our results indicate that at around 903 K, the activity of the ruthenium catalyst was high enough to minimize the difference between the rates of the steam reforming reactions of the pyrolysates from polystyrene and polypropylene. The proposed system thus has the flexibility to compensate for differences in chemical structures of municipal waste plastics. In addition, the steam reforming temperature was about 200 K lower than the temperature used in a conventional Ni-catalyzed process for the production of hydrogen. Low-temperature steam reforming allows for lower thermal input to the steam reformer, which results in an increase in thermal efficiency in the proposed process employing a Ru catalyst. Because low-temperature steam reforming can be also expected to reduce thermal degradation rates of the catalyst, the pyrolysis-steam reforming process with a Ru catalyst has the potential for use in small-scale production of hydrogen-rich gas from waste plastics that can be used for power generation.

  3. High Temperature Superconducting Underground Cable

    International Nuclear Information System (INIS)

    Farrell, Roger A.

    2010-01-01

    The purpose of this Project was to design, build, install and demonstrate the technical feasibility of an underground high temperature superconducting (HTS) power cable installed between two utility substations. In the first phase two HTS cables, 320 m and 30 m in length, were constructed using 1st generation BSCCO wire. The two 34.5 kV, 800 Arms, 48 MVA sections were connected together using a superconducting joint in an underground vault. In the second phase the 30 m BSCCO cable was replaced by one constructed with 2nd generation YBCO wire. 2nd generation wire is needed for commercialization because of inherent cost and performance benefits. Primary objectives of the Project were to build and operate an HTS cable system which demonstrates significant progress towards commercial progress and addresses real world utility concerns such as installation, maintenance, reliability and compatibility with the existing grid. Four key technical areas addressed were the HTS cable and terminations (where the cable connects to the grid), cryogenic refrigeration system, underground cable-to-cable joint (needed for replacement of cable sections) and cost-effective 2nd generation HTS wire. This was the worlds first installation and operation of an HTS cable underground, between two utility substations as well as the first to demonstrate a cable-to-cable joint, remote monitoring system and 2nd generation HTS.

  4. High-temperature axion potential

    International Nuclear Information System (INIS)

    Dowrick, N.J.; McDougall, N.A.

    1989-01-01

    We investigate the possibility of new terms in the high-temperature axion potential arising from the dynamical nature of the axion field and from higher-order corrections to the θ dependence in the free energy of the quark-gluon plasma. We find that the dynamical nature of the axion field does not affect the potential but that the higher-order effects lead to new terms in the potential which are larger than the term previously considered. However, neither the magnitude nor the sign of the potential can be calculated by a perturbative expansion of the free energy since the coupling is too large. We show that a change in the magnitude of the potential does not significantly affect the bound on the axion decay constant but that the sign of the potential is of crucial importance. By investigating the formal properties of the functional integral within the instanton dilute-gas approximation, we find that the sign of the potential does not change and that the minimum remains at θ=0. We conclude that the standard calculation of the axion energy today is not significantly modified by this investigation

  5. Creep of high temperature composites

    International Nuclear Information System (INIS)

    Sadananda, K.; Feng, C.R.

    1993-01-01

    High temperature creep deformation of composites is examined. Creep of composites depends on the interplay of many factors. One of the basic issues in the design of the creep resistant composites is the ability to predict their creep behavior from the knowledge of the creep behavior of the individual components. In this report, the existing theoretical models based on continuum mechanics principles are reviewed. These models are evaluated using extensive experimental data on molydisilicide-silicon carbide composites obtained by the authors. The analysis shows that the rule of mixture based on isostrain and isostress provides two limiting bounds wherein all other theoretical predictions fall. For molydisilicide composites, the creep is predominantly governed by the creep of the majority phase, i.e. the matrix with fibers deforming elastically. The role of back stresses both on creep rates and activation energies are shown to be minimum. Kinetics of creep in MoSi 2 is shown to be controlled by the process of dislocation glide with climb involving the diffusion of Mo atoms

  6. An experimental study of high-hydrogen welding processes

    Directory of Open Access Journals (Sweden)

    Fydrych, Dariusz

    2015-12-01

    Full Text Available This paper presents investigation results of determination of the diffusible hydrogen content in deposited metal obtained by means of two most often used methods-the glycerin method and the mercury method. Relation has been defined between results of those methods in the area characteristic of low-hydrogen as well as high-hydrogen welding processes. Relations available in the literature do not include the diffusible hydrogen content in deposited metal greater than 35 ml/100 g. Extending the scope of analysis of the diffusible hydrogen quantity to an 80 ml/100 g level considerably simplifies carrying out the steel weldability assessment with the use of high-hydrogen processes and with welding in water environment.Este trabajo presenta los resultados de una investigación sobre la determinación del contenido de hidrógeno difusible en el material aportado mediante dos métodos: el de la glicerina (el más utilizado y el del mercurio. El contenido de dicho hidrógeno se ha definido a partir de los resultados de esos métodos en una zona con bajo contenido en hidrógeno, así como procesos de soldadura con alto contenido en hidrógeno. No hay datos disponibles en la literatura para contenidos de hidrógeno difusible en metal depositado mayores de 35 ml/100 g. Ampliando el análisis de la cantidad de dicho hidrógeno hasta los 80 ml/100 g, se simplifica considerablemente la realización de ensayos de soldabilidad del acero en procesos de alto contenido en hidrógeno así como en la soldadura en medio acuoso.

  7. Lithium doping on covalent organic framework-320 for enhancing hydrogen storage at ambient temperature

    International Nuclear Information System (INIS)

    Xia, Liangzhi; Liu, Qing

    2016-01-01

    Density Functional Theory (DFT) combines with grand canonical Monte Carlo (GCMC) simulations are performed to explore the effect of Li doping on the hydrogen storage capability of COF-320. The results show that the interaction energy between the H 2 and the Li-doped COF-320 is about three times higher than that of pristine COF-320. GCMC simulations are employed to study the hydrogen uptake of Li-doped COF-320 at ambient temperature, further confirm that the lithium doping can improve the hydrogen uptake at ambient temperature. Our results demonstrate that Li-doped COFs have good potential in the field of hydrogen storage. - Graphical abstract: Fig. 1. The optimized cluster model used here to represent the COF-320 and possible adsorption sites (A, B, C) for adsorption of metals in the COF-320. The dangling bonds are terminated by H atoms. C, H, and N atoms are shown as gray, white, and blue colors, respectively. Fig. 2. The adsorption isotherm of H 2 in the pristine and Li-doped COF-320 at 298 K. - Highlights: • The binding sites of single and two lithium atoms in COF-320 were studied. • The interaction energy between the H 2 and the Li-doped COF-320 is about three times higher than that of pristine COF-320. • H 2 uptakes on the Li-doped COFs obtain significant improvement at ambient temperature. • Lithium-doping is a successful strategy for improving hydrogen uptake.

  8. Study of hydrogenated silicene: The initialization model of hydrogenation on planar, low buckled and high buckled structures of silicene

    International Nuclear Information System (INIS)

    Syaputra, Marhamni; Wella, Sasfan Arman; Wungu, Triati Dewi Kencana; Purqon, Acep; Suprijadi

    2015-01-01

    We study the hydrogenation structures possessed by silicene i.e. planar (PL), low buckled (LB) and high buckled (HB). On those structures we found the hydrogenation process occurs with some particular notes. Hydrogen stable position on the silicene surface is determined by its initial configuration. We only considered the fully hydrogenated case with the formula unit (SiH) n for all of these structures. Physical and electronic structure shift after the process are compared with hydrogenated graphene. Moreover, we observed a chemical process in the presence of hydrogen on the PL structure by nudged elastic band (NEB) which illustrates how hydrogen has a significant impact to the force barrier of the PL that changing it from its original structure

  9. Relationship between carbon microstructure, adsorption energy and hydrogen adsorption capacity at different temperatures

    International Nuclear Information System (INIS)

    Jagiello, J.; Thommes, M.

    2005-01-01

    Various microporous materials such as activated carbons, nano-tubes, synthetic micro-porous carbons as well as metal organic framework materials are being considered for hydrogen storage applications by means of physical adsorption. To develop materials of practical significance for hydrogen storage it is important to understand the relationships between pore sizes, adsorption energies and adsorption capacities. The pore size distribution (PSD) characterization is traditionally obtained from the analysis of nitrogen adsorption isotherms measured at 77 K. However, a portion of the pores accessible to H 2 may not be accessible to N 2 at this temperature. Therefore, it was recently proposed to use the DFT analysis of H 2 adsorption isotherms to characterize pore structure of materials considered for hydrogen storage applications [1]. In present work, adsorption isotherms of H 2 and N 2 at cryogenic temperatures are used for the characterization of carbon materials. Adsorption measurements were performed with Autosorb 1 MP [Quantachrome Instruments, Boynton Beach, Florida, USA]. As an example, Fig 1 compares PSDs calculated for the activated carbon sample (F400, Calgon Carbon) using combined H 2 and N 2 data, and using N 2 isotherm only. The nitrogen derived PSD does not include certain amount of micro-pores which are accessible to H 2 but not to N 2 molecules. Obviously, the difference in the calculated PSDs by the two methods will depend on the actual content of small micro-pores in a given sample. Carbon adsorption properties can also be characterized by the isosteric heat of adsorption, Qst, related to the adsorption energy and dependent on the carbon pore/surface structure. Fig 2 shows Qst data calculated using the Clausius-Clapeyron equation from H 2 isotherms measured at 77 K and 87 K for the carbon molecular sieve CMS 5A (Takeda), oxidized single wall nano-tubes (SWNT) [2], and graphitized carbon black (Supelco). The Qst values decrease with increasing pore

  10. High Electrocatalytic Hydrogen Evolution Activity of an Anomalous Ruthenium Catalyst

    KAUST Repository

    Zheng, Yao; Jiao, Yan; Zhu, Yihan; Li, Lu Hua; Han, Yu; Chen, Ying; Jaroniec, Mietek; Qiao, Shi Zhang

    2016-01-01

    Hydrogen evolution reaction (HER) is a critical process due to its fundamental role in electrocatalysis. Practically, the development of high-performance electrocatalysts for HER in alkaline media is of great importance for the conversion of renewable energy to hydrogen fuel via photoelectrochemical water splitting. However, both mechanistic exploration and materials development for HER under alkaline conditions are very limited. Precious Pt metal, which still serves as the state-of-the-art catalyst for HER, is unable to guarantee a sustainable hydrogen supply. Here we report an anomalously structured Ru catalyst that shows 2.5 times higher hydrogen generation rate than Pt and is among the most active HER electrocatalysts yet reported in alkaline solutions. The identification of new face-centered cubic crystallographic structure of Ru nanoparticles was investigated by high-resolution transmission electron microscopy imaging, and its formation mechanism was revealed by spectroscopic characterization and theoretical analysis. For the first time, it is found that the Ru nanocatalyst showed a pronounced effect of the crystal structure on the electrocatalytic activity tested under different conditions. The combination of electrochemical reaction rate measurements and density functional theory computation shows that the high activity of anomalous Ru catalyst in alkaline solution originates from its suitable adsorption energies to some key reaction intermediates and reaction kinetics in the HER process.

  11. High Electrocatalytic Hydrogen Evolution Activity of an Anomalous Ruthenium Catalyst.

    Science.gov (United States)

    Zheng, Yao; Jiao, Yan; Zhu, Yihan; Li, Lu Hua; Han, Yu; Chen, Ying; Jaroniec, Mietek; Qiao, Shi-Zhang

    2016-12-14

    Hydrogen evolution reaction (HER) is a critical process due to its fundamental role in electrocatalysis. Practically, the development of high-performance electrocatalysts for HER in alkaline media is of great importance for the conversion of renewable energy to hydrogen fuel via photoelectrochemical water splitting. However, both mechanistic exploration and materials development for HER under alkaline conditions are very limited. Precious Pt metal, which still serves as the state-of-the-art catalyst for HER, is unable to guarantee a sustainable hydrogen supply. Here we report an anomalously structured Ru catalyst that shows 2.5 times higher hydrogen generation rate than Pt and is among the most active HER electrocatalysts yet reported in alkaline solutions. The identification of new face-centered cubic crystallographic structure of Ru nanoparticles was investigated by high-resolution transmission electron microscopy imaging, and its formation mechanism was revealed by spectroscopic characterization and theoretical analysis. For the first time, it is found that the Ru nanocatalyst showed a pronounced effect of the crystal structure on the electrocatalytic activity tested under different conditions. The combination of electrochemical reaction rate measurements and density functional theory computation shows that the high activity of anomalous Ru catalyst in alkaline solution originates from its suitable adsorption energies to some key reaction intermediates and reaction kinetics in the HER process.

  12. High Electrocatalytic Hydrogen Evolution Activity of an Anomalous Ruthenium Catalyst

    KAUST Repository

    Zheng, Yao

    2016-11-28

    Hydrogen evolution reaction (HER) is a critical process due to its fundamental role in electrocatalysis. Practically, the development of high-performance electrocatalysts for HER in alkaline media is of great importance for the conversion of renewable energy to hydrogen fuel via photoelectrochemical water splitting. However, both mechanistic exploration and materials development for HER under alkaline conditions are very limited. Precious Pt metal, which still serves as the state-of-the-art catalyst for HER, is unable to guarantee a sustainable hydrogen supply. Here we report an anomalously structured Ru catalyst that shows 2.5 times higher hydrogen generation rate than Pt and is among the most active HER electrocatalysts yet reported in alkaline solutions. The identification of new face-centered cubic crystallographic