WorldWideScience

Sample records for plant hydrogen generation

  1. Hanford Waste Vitrification Plant hydrogen generation

    International Nuclear Information System (INIS)

    King, R.B.; King, A.D. Jr.; Bhattacharyya, N.K.

    1996-02-01

    The most promising method for the disposal of highly radioactive nuclear wastes is a vitrification process in which the wastes are incorporated into borosilicate glass logs, the logs are sealed into welded stainless steel canisters, and the canisters are buried in suitably protected burial sites for disposal. The purpose of the research supported by the Hanford Waste Vitrification Plant (HWVP) project of the Department of Energy through Battelle Pacific Northwest Laboratory (PNL) and summarized in this report was to gain a basic understanding of the hydrogen generation process and to predict the rate and amount of hydrogen generation during the treatment of HWVP feed simulants with formic acid. The objectives of the study were to determine the key feed components and process variables which enhance or inhibit the.production of hydrogen. Information on the kinetics and stoichiometry of relevant formic acid reactions were sought to provide a basis for viable mechanistic proposals. The chemical reactions were characterized through the production and consumption of the key gaseous products such as H 2 . CO 2 , N 2 0, NO, and NH 3 . For this mason this research program relied heavily on analyses of the gases produced and consumed during reactions of the HWVP feed simulants with formic acid under various conditions. Such analyses, used gas chromatographic equipment and expertise at the University of Georgia for the separation and determination of H 2 , CO, CO 2 , N 2 , N 2 O and NO

  2. Hydrogen Generation, Combustibility and Mitigation in Nuclear Power Plant Systems

    International Nuclear Information System (INIS)

    Talha, K.A.; El-Sheikh, B.M.; Gad El-Mawla, A.S.

    2003-01-01

    The nuclear power plant is provided with features to insure safety. The engineered safety features (ESFs) are devoted to set operating conditions under accident conditions. If ESFs fail to apply in some accidents, this would lead to what called severe accidents, and core damage. In this case hydrogen will be generated from different sources particularly from metal-water reactions. Since the containment is the final barrier to protect the environment from the release of radioactive materials; its integrity should not be threatened. In recent years, hydrogen concentration represents a real problem if it exceeds the combustibility limits. This work is devoted to calculate the amount of hydrogen to be generated, indelicate its combustibility and how to inertize the containment using different gases to maintain its integrity and protect the environment from the release of radioactive materials

  3. Chemical Plant Accidents in a Nuclear Hydrogen Generation Scheme

    International Nuclear Information System (INIS)

    Brown, Nicholas R.; Revankar, Shripad T.

    2011-01-01

    A high temperature nuclear reactor (HTR) could be used to drive a steam reformation plant, a coal gasification facility, an electrolysis plant, or a thermochemical hydrogen production cycle. Most thermochemical cycles are purely thermodynamic, and thus achieve high thermodynamic efficiency. HTRs produce large amounts of heat at high temperature (1100 K). Helium-cooled HTRs have many passive, or inherent, safety characteristics. This inherent safety is due to the high design basis limit of the maximum fuel temperature. Due to the severity of a potential release, containment of fission products is the single most important safety issue in any nuclear reactor facility. A HTR coupled to a chemical plant presents a complex system, due primarily to the interactive nature of both plants. Since the chemical plant acts as the heat sink for the nuclear reactor, it important to understand the interaction and feedback between the two systems. Process heat plants and HTRs are generally very different. Some of the major differences include: time constants of plants, safety standards, failure probability, and transient response. While both the chemical plant and the HTR are at advanced stages of testing individually, no serious effort has been made to understand the operation of the integrated system, especially during accident events that are initiated in the chemical plant. There is a significant lack of knowledge base regarding scaling and system integration for large scale process heat plants coupled to HTRs. Consideration of feedback between the two plants during time-dependent scenarios is absent from literature. Additionally, no conceptual studies of the accidents that could occur in either plant and impact the entire coupled system are present in literature

  4. Dependable Hydrogen and Industrial Heat Generation from the Next Generation Nuclear Plant

    Energy Technology Data Exchange (ETDEWEB)

    Charles V. Park; Michael W. Patterson; Vincent C. Maio; Piyush Sabharwall

    2009-03-01

    The Department of Energy is working with industry to develop a next generation, high-temperature gas-cooled nuclear reactor (HTGR) as a part of the effort to supply the US with abundant, clean and secure energy. The Next Generation Nuclear Plant (NGNP) project, led by the Idaho National Laboratory, will demonstrate the ability of the HTGR to generate hydrogen, electricity, and high-quality process heat for a wide range of industrial applications. Substituting HTGR power for traditional fossil fuel resources reduces the cost and supply vulnerability of natural gas and oil, and reduces or eliminates greenhouse gas emissions. As authorized by the Energy Policy Act of 2005, industry leaders are developing designs for the construction of a commercial prototype producing up to 600 MWt of power by 2021. This paper describes a variety of critical applications that are appropriate for the HTGR with an emphasis placed on applications requiring a clean and reliable source of hydrogen. An overview of the NGNP project status and its significant technology development efforts are also presented.

  5. Investment in hydrogen tri-generation for wastewater treatment plants under uncertainties

    Science.gov (United States)

    Gharieh, Kaveh; Jafari, Mohsen A.; Guo, Qizhong

    2015-11-01

    In this article, we present a compound real option model for investment in hydrogen tri-generation and onsite hydrogen dispensing systems for a wastewater treatment plant under price and market uncertainties. The ultimate objective is to determine optimal timing and investment thresholds to exercise initial and subsequent options such that the total savings are maximized. Initial option includes investment in a 1.4 (MW) Molten Carbonate Fuel Cell (MCFC) fed by mixture of waste biogas from anaerobic digestion and natural gas, along with auxiliary equipment. Produced hydrogen in MCFC via internal reforming, is recovered from the exhaust gas stream using Pressure Swing Adsorption (PSA) purification technology. Therefore the expansion option includes investment in hydrogen compression, storage and dispensing (CSD) systems which creates additional revenue by selling hydrogen onsite in retail price. This work extends current state of investment modeling within the context of hydrogen tri-generation by considering: (i) Modular investment plan for hydrogen tri-generation and dispensing systems, (ii) Multiple sources of uncertainties along with more realistic probability distributions, (iii) Optimal operation of hydrogen tri-generation is considered, which results in realistic saving estimation.

  6. Hydrogen generation comparison between lead-calcium and lead-antimony batteries in nuclear power plant

    International Nuclear Information System (INIS)

    Zhao Hongjun; Qi Suoni; Shen Yan; Li Jia

    2014-01-01

    Battery type selection is performed with the help of technical information supplied by vendors, and according to relevant criteria. Analysis and comparison of the hydrogen generation differences between two different lead-acid battery types are carried out through calculation. The analysis result may provide suggestions for battery type selection in nuclear power plant. (authors)

  7. Modeling Hydrogen Generation Rates in the Hanford Waste Treatment and Immobilization Plant

    Energy Technology Data Exchange (ETDEWEB)

    Camaioni, Donald M.; Bryan, Samuel A.; Hallen, Richard T.; Sherwood, David J.; Stock, Leon M.

    2004-03-29

    This presentation describes a project in which Hanford Site and Environmental Management Science Program investigators addressed issues concerning hydrogen generation rates in the Hanford waste treatment and immobilization plant. The hydrogen generation rates of radioactive wastes must be estimated to provide for safe operations. While an existing model satisfactorily predicts rates for quiescent wastes in Hanford underground storage tanks, pretreatment operations will alter the conditions and chemical composition of these wastes. Review of the treatment process flowsheet identified specific issues requiring study to ascertain whether the model would provide conservative values for waste streams in the plant. These include effects of adding hydroxide ion, alpha radiolysis, saturation with air (oxygen) from pulse-jet mixing, treatment with potassium permanganate, organic compounds from degraded ion exchange resins and addition of glass-former chemicals. The effects were systematically investigated through literature review, technical analyses and experimental work.

  8. Evaluation of Hybrid Power Plants using Biomass, Photovoltaics and Steam Electrolysis for Hydrogen and Power Generation

    Science.gov (United States)

    Petrakopoulou, F.; Sanz, J.

    2014-12-01

    Steam electrolysis is a promising process of large-scale centralized hydrogen production, while it is also considered an excellent option for the efficient use of renewable solar and geothermal energy resources. This work studies the operation of an intermediate temperature steam electrolyzer (ITSE) and its incorporation into hybrid power plants that include biomass combustion and photovoltaic panels (PV). The plants generate both electricity and hydrogen. The reference -biomass- power plant and four variations of a hybrid biomass-PV incorporating the reference biomass plant and the ITSE are simulated and evaluated using exergetic analysis. The variations of the hybrid power plants are associated with (1) the air recirculation from the electrolyzer to the biomass power plant, (2) the elimination of the sweep gas of the electrolyzer, (3) the replacement of two electric heaters with gas/gas heat exchangers, and (4) the replacement two heat exchangers of the reference electrolyzer unit with one heat exchanger that uses steam from the biomass power plant. In all cases, 60% of the electricity required in the electrolyzer is covered by the biomass plant and 40% by the photovoltaic panels. When comparing the hybrid plants with the reference biomass power plant that has identical operation and structure as that incorporated in the hybrid plants, we observe an efficiency decrease that varies depending on the scenario. The efficiency decrease stems mainly from the low effectiveness of the photovoltaic panels (14.4%). When comparing the hybrid scenarios, we see that the elimination of the sweep gas decreases the power consumption due to the elimination of the compressor used to cover the pressure losses of the filter, the heat exchangers and the electrolyzer. Nevertheless, if the sweep gas is used to preheat the air entering the boiler of the biomass power plant, the efficiency of the plant increases. When replacing the electric heaters with gas-gas heat exchangers, the

  9. Hydrogen production in early generation fusion power plant and its socio-economic implication

    International Nuclear Information System (INIS)

    Konishi, S.; Yamamoto, Y.

    2007-01-01

    Full text: This paper describes technical possibility of high temperature blanket for the early generation of fusion power plant and its application to hydrogen production. Its anticipated implication and strategy from the socio-economic aspects will be also discussed. Material and energy balances, such as fuel supply and delivery of product energy from fusion plants, as well as waste discharge and accident scenario that lead to environmental impact, are characterized by blanket concepts. Thus blankets are considered to dominate the feature of fusion energy that should respond to the requirements of the sponsors, i.e., public and future market. Fusion blanket concept based on the combinations of LiPb and SiC materials are regarded as a candidate for ITER/TBM, and at the same time, applied in various DEMO designs encompassing high temperature output. Recent developments of SiC-LiPb blanket in Japan, EU, US or China suggests staged development paths starting from TBMs and targeting high temperature blanket and efficient energy output from early generation plants. These strategies are strongly affected by the views of these parties on fusion energy, from the aspects of socio-economics. Hydrogen production process with the high temperature blanket is one of the most important issues, because temperature range much higher than is possible with current or near future fission plants are needed, suggesting market possibility different from that of fission. Fuel cycles, particularly lithium supply and TBR control will be also important. Self-sustained fusion fuel cycle requires technical capability to maintain the lithium contents. Liquid blanket has an advantage in continuous and real-time control TBR in a plant, but large amount of lithium-6 and initial tritium supply remains as issues. As for the environmental effect, normal operation release, assumed accidental scenario, and rad-waste will be the key issue to dominate social acceptance of fusion. (author)

  10. Hydrogen production in early generation fusion power plant and its socio-economic implication

    International Nuclear Information System (INIS)

    Konishi, Satoshi; Yamamoto, Yasushi

    2008-01-01

    This paper describes technical possibility of high temperature blanket for the early generation of fusion power plant and its application to hydrogen production. Its anticipated implication and strategy from the socio-economic aspects will be also discussed. Material and energy balances, such as fuel supply and delivery of product energy from fusion plants, as well as waste discharge and accident scenario that lead to environmental impact, are characterized by blanket concepts. Thus blankets are considered to dominate the feature of fusion energy that should respond to the requirements of the sponsors, i.e., public and future market. Fusion blanket concept based on the combinations of LiPb and SiC materials are regarded as a candidate for ITER/TBM, and at the same time, applied in various DEMO designs encompassing high temperature output. Recent developments of SiC-LiPb blanket in Japan, EU, US or China suggests staged development paths starting from TBMs and targeting high temperature blanket and efficient energy output from early generation plants. These strategies are strongly affected by the views of these parties on fusion energy, from the aspects of socio-economics. Hydrogen production process with the high temperature blanket is one of the most important issues, because temperature range much higher than is possible with current or near future fission plants are needed, suggesting market possibility different from that of fission. Fuel cycles, particularly lithium supply and TBR control will be also important. Self-sustained fusion fuel cycle requires technical capability to maintain the lithium contents. Liquid blanket has an advantage in continuous and real-time control TBR in a plant, but large amount of lithium-6 and initial tritium supply remains as issues. As for the environmental effect, normal operation release, assumed accidental scenario, and rad-waste will be the key issue to dominate social acceptance of fusion. (author)

  11. Impact of different metal turbidities on radiolytic hydrogen generation in nuclear power plants

    International Nuclear Information System (INIS)

    Kumbhar, A.G.; Belapurkar, A.D.; Venkateswaran, G.; Kishore, K.

    2005-01-01

    Radiolytic hydrogen generation on γ irradiation of turbid solutions containing metal turbidities such as titanium, nickel, iron, chromium, copper, indium, and aluminium was studied. It is suggested that the chemical reactivity of the metal in the turbid solution with e aq -/H/OH produced by radiolysis of water interferes with the recombination reactions which destroy H 2 and H 2 O 2 , thus leading to higher yield of hydrogen. The rate of generation of hydrogen and the G(H 2 ) value is related to the reactivity of the metal ion/hydroxylated species with the free radicals. (orig.)

  12. Study on the combustion behavior of radiolytically generated hydrogen explosion in small scale annular vessels at the reprocessing plant

    International Nuclear Information System (INIS)

    Kudo, Tatsuya; Tamauchi, Yoshikazu; Arai, Nobuyuki; Dai, Wenbin; Sakaihara, Motohiro; Kanehira, Osamu

    2017-01-01

    Hydrogen is generated by radiolysis of water, etc. in process vessels in reprocessing plant. Usually, the hydrogen is scavenged by compressed air into vessels to prevent hydrogen explosion. When an earthquake beyond design based occurs, for example, the compressed air may stop and the hydrogen starts accumulating in the vessels, and under this condition, an ignition source might set off hydrogen explosion. Therefore, the explosion derived by the radiolytically generated hydrogen is designated as one of severe accidents on Rokkasho Reprocessing Plant in new regulatory requirements. It is important to understand the combustion behavior of hydrogen explosion inside a vessel for consideration of safety measures against the severe accident, because the influences of detonation are not considered in the design basis of vessels. Especially, the investigations about the combustion behavior which considered influence of interior obstacles inside the vessel are not performed yet. In order to investigate the combustion behavior comprehensively, explosion experiment, combustion analysis and structural analysis are carried out using the representative vessels (small scale annular vessel, small scale plate vessel, large scale annular vessel and large scale cylindrical vessel) selected from Rokkasho Reprocessing Plant. In this paper, the results of experiments and analysis of small scale annular vessel (as one of representative vessel, imitated a pulsed column in the reprocessing plant) are reported. As imitated vessels, three vessels are manufactured with different interior obstacle arrangements as follows, A) cylindrical obstacles are faithfully reproduced and are arranged based on the actual vessel, B) cylindrical obstacles are arranged more densely than the actual vessel, and C) there are no obstacles inside the vessel. Experiments of hydrogen explosion are performed under condition of stoichiometric hydrogen-air ratio (premixed hydrogen-air is used). As a result of

  13. Hydrogen and methane generation from large hydraulic plant: Thermo-economic multi-level time-dependent optimization

    International Nuclear Information System (INIS)

    Rivarolo, M.; Magistri, L.; Massardo, A.F.

    2014-01-01

    Highlights: • We investigate H 2 and CH 4 production from very large hydraulic plant (14 GW). • We employ only “spilled energy”, not used by hydraulic plant, for H 2 production. • We consider the integration with energy taken from the grid at different prices. • We consider hydrogen conversion in chemical reactors to produce methane. • We find plants optimal size using a time-dependent thermo-economic approach. - Abstract: This paper investigates hydrogen and methane generation from large hydraulic plant, using an original multilevel thermo-economic optimization approach developed by the authors. Hydrogen is produced by water electrolysis employing time-dependent hydraulic energy related to the water which is not normally used by the plant, known as “spilled water electricity”. Both the demand for spilled energy and the electrical grid load vary widely by time of year, therefore a time-dependent hour-by-hour one complete year analysis has been carried out, in order to define the optimal plant size. This time period analysis is necessary to take into account spilled energy and electrical load profiles variability during the year. The hydrogen generation plant is based on 1 MWe water electrolysers fuelled with the “spilled water electricity”, when available; in the remaining periods, in order to assure a regular H 2 production, the energy is taken from the electrical grid, at higher cost. To perform the production plant size optimization, two hierarchical levels have been considered over a one year time period, in order to minimize capital and variable costs. After the optimization of the hydrogen production plant size, a further analysis is carried out, with a view to converting the produced H 2 into methane in a chemical reactor, starting from H 2 and CO 2 which is obtained with CCS plants and/or carried by ships. For this plant, the optimal electrolysers and chemical reactors system size is defined. For both of the two solutions, thermo

  14. Maintaining a Technology-Neutral Approach to Hydrogen Production Process Development through Conceptual Design of the Next Generation Nuclear Plant

    International Nuclear Information System (INIS)

    Michael W. Patterson

    2008-01-01

    The Next Generation Nuclear Plant (NGNP) project was authorized in the Energy Policy Act of 2005 (EPAct), tasking the U.S. Department of Energy (DOE) with demonstrating High Temperature Gas-Cooled Reactor (HTGR) technology. The demonstration is to include the technical, licensing, operational, and commercial viability of HTGR technology for the production of electricity and hydrogen. The Nuclear Hydrogen Initiative (NHI), a component of the DOE Hydrogen Program managed by the Office of Nuclear Energy, is also investigating multiple approaches to cost effective hydrogen production from nuclear energy. The objective of NHI is development of the technology and information basis for a future decision on commercial viability. The initiatives are clearly intertwined. While the objectives of NGNP and NHI are generally consistent, NGNP has progressed to the project definition phase and the project plan has matured. Multiple process applications for the NGNP require process heat, electricity and hydrogen in varied combinations and sizes. Coupling these processes to the reactor in multiple configurations adds complexity to the design, licensing and demonstration of both the reactor and the hydrogen production process. Commercial viability of hydrogen production may depend on the specific application and heat transport configuration. A component test facility (CTF) is planned by the NGNP to support testing and demonstration of NGNP systems, including those for hydrogen production, in multiple configurations. Engineering-scale demonstrations in the CTF are expected to start in 2012 to support scheduled design and licensing activities leading to subsequent construction and operation. Engineering-scale demonstrations planned by NHI are expected to start at least two years later. Reconciliation of these schedules is recommended to successfully complete both initiatives. Hence, closer and earlier integration of hydrogen process development and heat transport systems is sensible

  15. Hanford waste vitrification plant hydrogen generation study: Preliminary evaluation of alternatives to formic acid

    International Nuclear Information System (INIS)

    King, R.B.; Bhattacharyya, N.K.; Kumar, V.

    1996-02-01

    Oxalic, glyoxylic, glycolic, malonic, pyruvic, lactic, levulinic, and citric acids as well as glycine have been evaluated as possible substitutes for formic acid in the preparation of feed for the Hanford waste vitrification plant using a non-radioactive feed stimulant UGA-12M1 containing substantial amounts of aluminum and iron oxides as well as nitrate and nitrite at 90C in the presence of hydrated rhodium trichloride. Unlike formic acid none of these carboxylic acids liberate hydrogen under these conditions and only malonic and citric acids form ammonia. Glyoxylic, glycolic, malonic, pyruvic, lactic, levulinic, and citric acids all appear to have significant reducing properties under the reaction conditions of interest as indicated by the observation of appreciable amounts of N 2 O as a reduction product of,nitrite or, less likely, nitrate at 90C. Glyoxylic, pyruvic, and malonic acids all appear to be unstable towards decarboxylation at 90C in the presence of Al(OH) 3 . Among the carboxylic acids investigated in this study the α-hydroxycarboxylic acids glycolic and lactic acids appear to be the most interesting potential substitutes for formic acid in the feed preparation for the vitrification plant because of their failure to produce hydrogen or ammonia or to undergo decarboxylation under the reaction conditions although they exhibit some reducing properties in feed stimulant experiments

  16. Hydrogen and acoustic detection in steam generators of Super Phenix power plant

    International Nuclear Information System (INIS)

    Kong, N.; Le Bris, A.; Berthier, P.

    1986-05-01

    During the isothermal tests of Super-Phenix, two types of measurements were made on the steam generators with regard to the detection of water leaks into the sodium: - the first measurements enabled us to determine the characteristics (sensitivity, response time) of the hydrogen detectors that are already operational for the filling with water and the power operation of the steam generators. They also provided the basis for developing a prototype system for detecting very small water leaks (microleak phase). The other measurements concern the qualification tests of acoustic detectors which have been fitted for the first time to a major industrial installation. The results obtained are very satisfactory but final validation of the acoustic method will only occur after the full-power tests [fr

  17. Hydrogen Generation From Electrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Steven Cohen; Stephen Porter; Oscar Chow; David Henderson

    2009-03-06

    today that perform in a range of efficiencies, >95%, that are suitable for the overall operational goals. The balance of plant scales well both operationally and in terms of cost becoming a smaller portion of the overall cost equation as the systems get larger. Capital cost reduction of the cell stack power supplies is achievable by modifying the system configuration to have the cell stacks in electrical series driving up the DC bus voltage, thereby allowing the use of large-scale DC power supply technologies. The single power supply approach reduces cost. Elements of the cell stack cost reduction and efficiency improvement work performed in the early stage of the program is being continued in subsequent DOE sponsored programs and through internal investment by Proton. The results of the trade study of the 100 kg H2/day system have established a conceptual platform for design and development of a next generation electrolyzer for Proton. The advancements started by this program have the possibility of being realized in systems for the developing fueling markets in 2010 period.

  18. Hydrogen storage and generation system

    Science.gov (United States)

    Dentinger, Paul M.; Crowell, Jeffrey A. W.

    2010-08-24

    A system for storing and generating hydrogen generally and, in particular, a system for storing and generating hydrogen for use in an H.sub.2/O.sub.2 fuel cell. The hydrogen storage system uses the beta particles from a beta particle emitting material to degrade an organic polymer material to release substantially pure hydrogen. In a preferred embodiment of the invention, beta particles from .sup.63Ni are used to release hydrogen from linear polyethylene.

  19. MOPABA-H2 - Computer code for calculation of hydrogen generation and distribution in the equipment of power plants with WWER type reactors in design modes of operation

    International Nuclear Information System (INIS)

    Arkhipov, O.P.; Kharitonov, Yu.V.; Shumskiy, A.M.; Kabakchi, S.A.

    2002-01-01

    With the aim of ensuring the hydrogen explosive-proof situation in the reactor plant, a complex of scientific-and-research work was carried out including the following: revealing the mechanisms of generation and release of hydrogen in the primary equipment components under design operation modes of the reactor plant with WWER; development of calculation procedure and computer code MOPABA-H2 enabling to determine the hydrogen content in RP equipment components under design operation modes. In the process of procedure development it was found out that the calculation of hydrogen content in the plant equipment requires development of the following main mathematical models: radiochemical processes in the primary coolant which has impurities and added special reagents; absorption of the core ionizing radiation by the coolant; steam-zirconium reaction (during design-basis accident of LOCA type); coolant mass transfer over the reactor plant equipment including transition of the phase boundary by the components of the coolant. (author)

  20. Hydrogen generation by metal corrosion in simulated Waste Isolation Pilot Plant environments

    International Nuclear Information System (INIS)

    Telander, M.R.; Westerman, R.E.

    1993-09-01

    The corrosion and gas-generation characteristics of three material types: low-carbon steel (the current waste packaging material for the Waste Isolation Pilot Plant), Cu-base materials, and Ti-base materials were determined in both the liquid and vapor phase of Brine A, a brine representative of an intergranular Salado Formation brine. Test environments included anoxic brine and anoxic brine with overpressures of CO 2 , H 2 S, and H 2 . Low-carbon steel reacted at a slow, measurable rate with anoxic brine, liberating H 2 on an equimolar basis with Fe reacted. Presence of CO 2 caused the initial reaction to proceed more rapidly, but CO 2 -induced passivation stopped the reaction if the CO 2 were present in sufficient quantities. Low-carbon steel immersed in brine with H 2 S showed no reaction, apparently because of passivation of the steel by formation of a protective iron sulfide reaction product. Cu- and Ti-base materials showed essentially no corrosion when exposed to brine and overpressures of N 2 , CO 2 , and H 2 S except for the rapid and complete reaction between Cu-base materials and H 2 S. No significant reaction took place on any material in any environment in the vapor-phase exposures

  1. Hydrogen generation by metal corrosion in simulated Waste Isolation Pilot Plant environments. Final report

    International Nuclear Information System (INIS)

    Telander, M.R.; Westerman, R.E.

    1997-03-01

    The corrosion and gas-generation characteristics of four material types: low-carbon steel (the current waste packaging material for the Waste Isolation Pilot Plant), Cu-base and Ti-base (alternative packaging) materials, and Al-base (simulated waste) materials were determined in both the liquid and vapor phase of Brine A, a brine representative of an intergranular Salado Formation brine. Test environments consisted primarily of anoxic brine with overpressures of N 2 , CO 2 , H 2 S, and H 2 . Limited tests of low-carbon steel were also performed in simulated-backfill environments and in brine environments with pH values ranging from 3 to 11. Low-carbon steel reacted at a slow, measurable rate with anoxic brine, liberating H 2 on an equimolar basis with Fe reacted. Presence of CO 2 caused the initial reaction to proceed more rapidly, but CO 2 -induced passivation stopped the reaction if the CO 2 were present in sufficient quantities. Addition of H 2 S to a CO 2 -passivated system caused reversal of the passivation. Low-carbon steel immersed in brine with H 2 S showed no reaction, apparently because of passivation of the steel by formation of FeS. Addition of CO 2 to an H 2 S-passivated system did not reverse the passivation. Cu- and Ti-base materials showed essentially no corrosion when exposed to brine and overpressures of N 2 , CO 2 , and H 2 S except for the rapid and complete reaction between Cu-base materials and H 2 S. The Al-base materials reacted at approximately the same rate as low-carbon steel when immersed in anoxic Brine A; considerably more rapidly in the presence of CO 2 or H 2 S; and much more rapidly when iron was present in the system as a brine contaminant. High-purity Al was much more susceptible to corrosion than the 6061 alloy. No significant reaction took place on any material in any environment in the vapor-phase exposures

  2. Hydrogen generation by metal corrosion in simulated Waste Isolation Pilot Plant environments. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Telander, M.R.; Westerman, R.E. [Battelle Pacific Northwest Lab., Richland, WA (United States)

    1997-03-01

    The corrosion and gas-generation characteristics of four material types: low-carbon steel (the current waste packaging material for the Waste Isolation Pilot Plant), Cu-base and Ti-base (alternative packaging) materials, and Al-base (simulated waste) materials were determined in both the liquid and vapor phase of Brine A, a brine representative of an intergranular Salado Formation brine. Test environments consisted primarily of anoxic brine with overpressures of N{sub 2}, CO{sub 2}, H{sub 2}S, and H{sub 2}. Limited tests of low-carbon steel were also performed in simulated-backfill environments and in brine environments with pH values ranging from 3 to 11. Low-carbon steel reacted at a slow, measurable rate with anoxic brine, liberating H{sub 2} on an equimolar basis with Fe reacted. Presence of CO{sub 2} caused the initial reaction to proceed more rapidly, but CO{sub 2}-induced passivation stopped the reaction if the CO{sub 2} were present in sufficient quantities. Addition of H{sub 2}S to a CO{sub 2}-passivated system caused reversal of the passivation. Low-carbon steel immersed in brine with H{sub 2}S showed no reaction, apparently because of passivation of the steel by formation of FeS. Addition of CO{sub 2} to an H{sub 2}S-passivated system did not reverse the passivation. Cu- and Ti-base materials showed essentially no corrosion when exposed to brine and overpressures of N{sub 2}, CO{sub 2}, and H{sub 2}S except for the rapid and complete reaction between Cu-base materials and H{sub 2}S. The Al-base materials reacted at approximately the same rate as low-carbon steel when immersed in anoxic Brine A; considerably more rapidly in the presence of CO{sub 2} or H{sub 2}S; and much more rapidly when iron was present in the system as a brine contaminant. High-purity Al was much more susceptible to corrosion than the 6061 alloy. No significant reaction took place on any material in any environment in the vapor-phase exposures.

  3. Hydrogen production at hydro-power plants

    Science.gov (United States)

    Tarnay, D. S.

    A tentative design for hydrogen-producing installations at hydropower facilities is discussed from technological, economic and applications viewpoints. The plants would use alternating current to electrolyze purified river water. The hydrogen would be stored in gas or liquid form and oxygen would be sold or vented to the atmosphere. The hydrogen could later be burned in a turbine generator for meeting peak loads, either in closed or open cycle systems. The concept would allow large hydroelectric plants to function in both base- and peak-load modes, thus increasing the hydraulic utilization of the plant and the capacity factor to a projected 0.90. Electrolyzer efficiencies ranging from 0.85-0.90 have been demonstrated. Excess hydrogen can be sold for other purposes or, eventually, as domestic and industrial fuel, at prices competitive with current industrial hydrogen.

  4. Maintaining a technology-neutral approach to hydrogen production process development through conceptual design of the next generation nuclear plant - HTR2008-58191

    International Nuclear Information System (INIS)

    Patterson, M. W.; Park, C. V.

    2008-01-01

    The Energy Policy Act of 2005 (EPAct) charges the Dept. of Energy (DOE) with developing and demonstrating the technical and economic feasibility of using high temperature gas-cooled reactor (HTGR) technology for the production of electricity and/or hydrogen. The design, construction and demonstration of this technology in an HTGR proto-type reactor are termed the Next Generation Nuclear Plant (NGNP) Project. Currently, parallel development of three hydrogen production processes will continue until a single process technology is recommended for final demonstration in the NGNP - a technology neutral approach. This analysis compares the technology neutral approach to acceleration of the hydrogen process down-selection at the completion of the NGNP conceptual design to improve integration of the hydrogen process development and NGNP Project schedule. The accelerated schedule activities are based on completing evaluations and achieving technology readiness levels (TRLs) identified in NGNP systems engineering and technology road-maps. The cost impact of accelerating the schedule and risk reduction strategies was also evaluated. The NGNP Project intends to design and construct a component test facility (CTF) to support testing and demonstration of HTGR technologies, including those for hydrogen production. The demonstrations will support scheduled design and licensing activities, leading to subsequent construction and operation of the NGNP. Demonstrations in the CTF are expected to start about two years earlier than similarly scaled hydrogen demonstrations planned in the technology neutral baseline. The schedule evaluation assumed that hydrogen process testing would be performed in the CTF and synchronized the progression of hydrogen process development with CTF availability. (authors)

  5. Theoretical Design of a Thermosyphon for Efficient Process Heat Removal from Next Generation Nuclear Plant (NGNP) for Production of Hydrogen

    International Nuclear Information System (INIS)

    Piyush Sabharwall; Fred Gunnerson; Akira Tokuhiro; Vivek Utgiker; Kevan Weaver; Steven Sherman

    2007-01-01

    The work reported here is the preliminary analysis of two-phase Thermosyphon heat transfer performance with various alkali metals. Thermosyphon is a device for transporting heat from one point to another with quite extraordinary properties. Heat transport occurs via evaporation and condensation, and the heat transport fluid is re-circulated by gravitational force. With this mode of heat transfer, the thermosyphon has the capability to transport heat at high rates over appreciable distances, virtually isothermally and without any requirement for external pumping devices. For process heat, intermediate heat exchangers (IHX) are required to transfer heat from the NGNP to the hydrogen plant in the most efficient way possible. The production of power at higher efficiency using Brayton Cycle, and hydrogen production requires both heat at higher temperatures (up to 1000 C) and high effectiveness compact heat exchangers to transfer heat to either the power or process cycle. The purpose for selecting a compact heat exchanger is to maximize the heat transfer surface area per volume of heat exchanger; this has the benefit of reducing heat exchanger size and heat losses. The IHX design requirements are governed by the allowable temperature drop between the outlet of the NGNP (900 C, based on the current capabilities of NGNP), and the temperatures in the hydrogen production plant. Spiral Heat Exchangers (SHE's) have superior heat transfer characteristics, and are less susceptible to fouling. Further, heat losses to surroundings are minimized because of its compact configuration. SHEs have never been examined for phase-change heat transfer applications. The research presented provides useful information for thermosyphon design and Spiral Heat Exchanger

  6. Balance of Plant Requirements for a Nuclear Hydrogen Plant

    Energy Technology Data Exchange (ETDEWEB)

    Bradley Ward

    2006-04-01

    This document describes the requirements for the components and systems that support the hydrogen production portion of a 600 megawatt thermal (MWt) Next Generation Nuclear Plant (NGNP). These systems, defined as the "balance-of-plant" (BOP), are essential to operate an effective hydrogen production plant. Examples of BOP items are: heat recovery and heat rejection equipment, process material transport systems (pumps, valves, piping, etc.), control systems, safety systems, waste collection and disposal systems, maintenance and repair equipment, heating, ventilation, and air conditioning (HVAC), electrical supply and distribution, and others. The requirements in this document are applicable to the two hydrogen production processes currently under consideration in the DOE Nuclear Hydrogen Initiative. These processes are the sulfur iodide (S-I) process and the high temperature electrolysis (HTE) process. At present, the other two hydrogen production process - the hybrid sulfur-iodide electrolytic process (SE) and the calcium-bromide process (Ca-Br) -are under flow sheet development and not included in this report. While some features of the balance-of-plant requirements are common to all hydrogen production processes, some details will apply only to the specific needs of individual processes.

  7. Storage, generation, and use of hydrogen

    Science.gov (United States)

    McClaine, Andrew W.; Rolfe, Jonathan L.; Larsen, Christopher A.; Konduri, Ravi K.

    2006-05-30

    A composition comprising a carrier liquid; a dispersant; and a chemical hydride. The composition can be used in a hydrogen generator to generate hydrogen for use, e.g., as a fuel. A regenerator recovers elemental metal from byproducts of the hydrogen generation process.

  8. Fuel cell using a hydrogen generation system

    Science.gov (United States)

    Dentinger, Paul M.; Crowell, Jeffrey A. W.

    2010-10-19

    A system is described for storing and generating hydrogen and, in particular, a system for storing and generating hydrogen for use in an H.sub.2/O.sub.2 fuel cell. The hydrogen storage system uses beta particles from a beta particle emitting material to degrade an organic polymer material to release substantially pure hydrogen. In a preferred embodiment of the invention, beta particles from .sup.63Ni are used to release hydrogen from linear polyethylene.

  9. Texaco, carbide form hydrogen plant venture

    International Nuclear Information System (INIS)

    Anon.

    1992-01-01

    This paper reports that Texaco Inc. and Union Carbide Industrial Gases Inc. (UCIG) have formed a joint venture to develop and operate hydrogen plants. The venture, named HydroGEN Supply Co., is owned by Texaco Hydrogen Inc., a wholly owned subsidiary of Texaco, and UCIG Hydrogen Services Inc., a wholly owned subsidiary of UCIG. Plants built by HydroGEN will combine Texaco's HyTEX technology for hydrogen production with UCIG's position in cryogenic and advanced air separation technology. Texaco the U.S. demand for hydrogen is expected to increase sharply during the next decade, while refinery hydrogen supply is expected to drop. The Clean Air Act amendments of 1990 require U.S. refiners to lower aromatics in gasoline, resulting in less hydrogen recovered by refiners from catalytic reforming units. Meanwhile, requirements to reduce sulfur in diesel fuel will require more hydrogen capacity

  10. Third generation nuclear plants

    Science.gov (United States)

    Barré, Bertrand

    2012-05-01

    After the Chernobyl accident, a new generation of Light Water Reactors has been designed and is being built. Third generation nuclear plants are equipped with dedicated systems to insure that if the worst accident were to occur, i.e. total core meltdown, no matter how low the probability of such occurrence, radioactive releases in the environment would be minimal. This article describes the EPR, representative of this "Generation III" and a few of its competitors on the world market.

  11. Hydrogen-based power generation from bioethanol steam reforming

    Energy Technology Data Exchange (ETDEWEB)

    Tasnadi-Asztalos, Zs., E-mail: tazsolt@chem.ubbcluj.ro; Cormos, C. C., E-mail: cormos@chem.ubbcluj.ro; Agachi, P. S. [Babes-Bolyai University, Faculty of Chemistry and Chemical Engineering, 11 Arany Janos, Postal code: 400028, Cluj-Napoca (Romania)

    2015-12-23

    This paper is evaluating two power generation concepts based on hydrogen produced from bioethanol steam reforming at industrial scale without and with carbon capture. The power generation from bioethanol conversion is based on two important steps: hydrogen production from bioethanol catalytic steam reforming and electricity generation using a hydrogen-fuelled gas turbine. As carbon capture method to be assessed in hydrogen-based power generation from bioethanol steam reforming, the gas-liquid absorption using methyl-di-ethanol-amine (MDEA) was used. Bioethanol is a renewable energy carrier mainly produced from biomass fermentation. Steam reforming of bioethanol (SRE) provides a promising method for hydrogen and power production from renewable resources. SRE is performed at high temperatures (e.g. 800-900°C) to reduce the reforming by-products (e.g. ethane, ethene). The power generation from hydrogen was done with M701G2 gas turbine (334 MW net power output). Hydrogen was obtained through catalytic steam reforming of bioethanol without and with carbon capture. For the evaluated plant concepts the following key performance indicators were assessed: fuel consumption, gross and net power outputs, net electrical efficiency, ancillary consumptions, carbon capture rate, specific CO{sub 2} emission etc. As the results show, the power generation based on bioethanol conversion has high energy efficiency and low carbon footprint.

  12. Hydrogen-based power generation from bioethanol steam reforming

    International Nuclear Information System (INIS)

    Tasnadi-Asztalos, Zs.; Cormos, C. C.; Agachi, P. S.

    2015-01-01

    This paper is evaluating two power generation concepts based on hydrogen produced from bioethanol steam reforming at industrial scale without and with carbon capture. The power generation from bioethanol conversion is based on two important steps: hydrogen production from bioethanol catalytic steam reforming and electricity generation using a hydrogen-fuelled gas turbine. As carbon capture method to be assessed in hydrogen-based power generation from bioethanol steam reforming, the gas-liquid absorption using methyl-di-ethanol-amine (MDEA) was used. Bioethanol is a renewable energy carrier mainly produced from biomass fermentation. Steam reforming of bioethanol (SRE) provides a promising method for hydrogen and power production from renewable resources. SRE is performed at high temperatures (e.g. 800-900°C) to reduce the reforming by-products (e.g. ethane, ethene). The power generation from hydrogen was done with M701G2 gas turbine (334 MW net power output). Hydrogen was obtained through catalytic steam reforming of bioethanol without and with carbon capture. For the evaluated plant concepts the following key performance indicators were assessed: fuel consumption, gross and net power outputs, net electrical efficiency, ancillary consumptions, carbon capture rate, specific CO 2 emission etc. As the results show, the power generation based on bioethanol conversion has high energy efficiency and low carbon footprint

  13. Hydrogen-based power generation from bioethanol steam reforming

    Science.gov (United States)

    Tasnadi-Asztalos, Zs.; Cormos, C. C.; Agachi, P. S.

    2015-12-01

    This paper is evaluating two power generation concepts based on hydrogen produced from bioethanol steam reforming at industrial scale without and with carbon capture. The power generation from bioethanol conversion is based on two important steps: hydrogen production from bioethanol catalytic steam reforming and electricity generation using a hydrogen-fuelled gas turbine. As carbon capture method to be assessed in hydrogen-based power generation from bioethanol steam reforming, the gas-liquid absorption using methyl-di-ethanol-amine (MDEA) was used. Bioethanol is a renewable energy carrier mainly produced from biomass fermentation. Steam reforming of bioethanol (SRE) provides a promising method for hydrogen and power production from renewable resources. SRE is performed at high temperatures (e.g. 800-900°C) to reduce the reforming by-products (e.g. ethane, ethene). The power generation from hydrogen was done with M701G2 gas turbine (334 MW net power output). Hydrogen was obtained through catalytic steam reforming of bioethanol without and with carbon capture. For the evaluated plant concepts the following key performance indicators were assessed: fuel consumption, gross and net power outputs, net electrical efficiency, ancillary consumptions, carbon capture rate, specific CO2 emission etc. As the results show, the power generation based on bioethanol conversion has high energy efficiency and low carbon footprint.

  14. Automotive dual-mode hydrogen generation system

    Science.gov (United States)

    Kelly, D. A.

    The automotive dual mode hydrogen generation system is advocated as a supplementary hydrogen fuel means along with the current metallic hydride hydrogen storage method for vehicles. This system consists of utilizing conventional electrolysis cells with the low voltage dc electrical power supplied by two electrical generating sources within the vehicle. Since the automobile engine exhaust manifold(s) are presently an untapped useful source of thermal energy, they can be employed as the heat source for a simple heat engine/generator arrangement. The second, and minor electrical generating means consists of multiple, miniature air disk generators which are mounted directly under the vehicle's hood and at other convenient locations within the engine compartment. The air disk generators are revolved at a speed which is proportionate to the vehicles forward speed and do not impose a drag on the vehicles motion.

  15. Geothermal Power Generation Plant

    Energy Technology Data Exchange (ETDEWEB)

    Boyd, Tonya [Oregon Inst. of Technology, Klamath Falls, OR (United States). Geo-Heat Center

    2013-12-01

    Oregon Institute of Technology (OIT) drilled a deep geothermal well on campus (to 5,300 feet deep) which produced 196°F resource as part of the 2008 OIT Congressionally Directed Project. OIT will construct a geothermal power plant (estimated at 1.75 MWe gross output). The plant would provide 50 to 75 percent of the electricity demand on campus. Technical support for construction and operations will be provided by OIT’s Geo-Heat Center. The power plant will be housed adjacent to the existing heat exchange building on the south east corner of campus near the existing geothermal production wells used for heating campus. Cooling water will be supplied from the nearby cold water wells to a cooling tower or air cooling may be used, depending upon the type of plant selected. Using the flow obtained from the deep well, not only can energy be generated from the power plant, but the “waste” water will also be used to supplement space heating on campus. A pipeline will be construction from the well to the heat exchanger building, and then a discharge line will be construction around the east and north side of campus for anticipated use of the “waste” water by facilities in an adjacent sustainable energy park. An injection well will need to be drilled to handle the flow, as the campus existing injection wells are limited in capacity.

  16. A method for generating hydrogen from water

    International Nuclear Information System (INIS)

    Godin, Paul; Mascarello, Jean; Millet, Jacques.

    1974-01-01

    Description is given of a method and an installation for generating hydrogen from water, through an endothermic cycle of several successive chemical reactions involving intermediate substances regenerated during said cycle, said reactions occuring at different temperatures. The reaction which takes place at the highest temperature is carried out electrochemically. This can be applied to power-generating units comprising a nuclear reactor [fr

  17. Next Generation Nuclear Plant System Requirements Manual

    International Nuclear Information System (INIS)

    Not Listed

    2008-01-01

    System Requirements Manual for the NGNP Project. The Energy Policy Act of 2005 (H.R. 6; EPAct), which was signed into law by President George W. Bush in August 2005, required the Secretary of the U.S. Department of Energy (DOE) to establish a project to be known as the Next Generation Nuclear Plant (NGNP) Project. According to the EPAct, the NGNP Project shall consist of the research, development, design, construction, and operation of a prototype plant (to be referred to herein as the NGNP) that (1) includes a nuclear reactor based on the research and development (R and D) activities supported by the Generation IV Nuclear Energy Systems initiative, and (2) shall be used to generate electricity, to produce hydrogen, or to both generate electricity and produce hydrogen. The NGNP Project supports both the national need to develop safe, clean, economical nuclear energy and the Nuclear Hydrogen Initiative (NHI), which has the goal of establishing greenhouse-gas-free technologies for the production of hydrogen. The DOE has selected the helium-cooled High Temperature Gas-Cooled Reactor (HTGR) as the reactor concept to be used for the NGNP because it is the only near-term Generation IV concept that has the capability to provide process heat at high-enough temperatures for highly efficient production of hydrogen. The EPAct also names the Idaho National Laboratory (INL), the DOE's lead national laboratory for nuclear energy research, as the site for the prototype NGNP

  18. 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)

  19. Effects of hydrogen fluoride on plants

    Energy Technology Data Exchange (ETDEWEB)

    Yamazoe, F

    1970-07-15

    Symptoms of fluorosis in plants are chlorotic markings around the tip or edges of young leaves. Examples of damage to plants and livestock by fluorides are listed, including the retarded growth of silkworms fed on mulberry leaves polluted by more than 30 ppm fluorides. Plants can be classified into six groups according to their resistance to hydrogen fluoride. Threshold values of the fluoride concentration range from 5-10 ppb for the plants. Gladiolus is normally employed as a plant indicator for hydrogen fluoride and silkworms as indicator insects. The relationship between plant damage by fluorides and exposure time, density, soil, fertilizer, meteorology and location are examined. Several preventive measures are listed, including the spraying of water or lime on plant leaves. It is concluded that the establishment of an environmental standard is difficult because of the extremely high sensitivity of the plants to the gas. 8 references.

  20. Hydrogen generator characteristics for storage of renewably-generated energy

    International Nuclear Information System (INIS)

    Kotowicz, Janusz; Bartela, Łukasz; Węcel, Daniel; Dubiel, Klaudia

    2017-01-01

    The paper presents a methodology for determining the efficiency of a hydrogen generator taking the power requirements of its auxiliary systems into account. Authors present results of laboratory experiments conducted on a hydrogen generator containing a PEM water electrolyzer for a wide range of device loads. On the basis of measurements, the efficiency characteristics of electrolyzers were determined, including that of an entire hydrogen generator using a monitored power supply for its auxiliary devices. Based on the results of the experimental tests, the authors have proposed generalized characteristics of hydrogen generator efficiency. These characteristics were used for analyses of a Power-to-Gas system cooperating with a 40 MW wind farm with a known yearly power distribution. It was assumed that nightly-produced hydrogen is injected into the natural gas transmission system. An algorithm for determining the thermodynamic and economic characteristics of a Power-to-Gas installation is proposed. These characteristics were determined as a function of the degree of storage of the energy produced in a Renewable Energy Sources (RES) installation, defined as the ratio of the amount of electricity directed to storage to the annual amount of electricity generated in the RES installation. Depending on the degree of storage, several quantities were determined. - Highlights: • The efficiency characteristics of PEM electrolyzer are determined. • Generalized characteristics of hydrogen generator efficiency are proposed. • Method of choice of electrolyser nominal power for Power-to-Gas system was proposed. • Development of Power-to-Gas systems requires implementation of support mechanisms.

  1. Hydrogen risk reduction in Nuclear power plant

    International Nuclear Information System (INIS)

    Movahed, M.A.; Travis, J.R.

    1999-01-01

    In case of a severe accident in a nuclear power plant with core melt and hydrogen production, the hydrogen risk is one of the main concerns. It may jeopardize the containment integrity due to violent deflagration that can lead to DDT (Deflagration Detonation Transient) or even detonation of proper hydrogen mitigation means are not available. The design of the EPR (European Pressurized water Reactor) Hydrogen mitigation and control system is based on the lumped parameter code WAVCO and the 3D code GASFLOW. The concept consists of recombiners and igniters to cope with all scenarios including those without steam. The system has been checked to avoid DDT by the 7λ criteria that's implemented in GASFLOW. Future analysis could deal with determining dynamic pressure loads, if appropriate, and some sensitivity studies to check the hydrogen control measures with respect to different source locations and mass flow rates. Also a conditional criterion for determining the likelihood of fast deflagration should be developed. (author)

  2. Hydrogen generation from biogenic and fossil fuels by autothermal reforming

    Science.gov (United States)

    Rampe, Thomas; Heinzel, Angelika; Vogel, Bernhard

    Hydrogen generation for fuel cell systems by reforming technologies from various fuels is one of the main fields of investigation of the Fraunhofer ISE. Suitable fuels are, on the one hand, gaseous hydrocarbons like methane, propane but also, on the other hand, liquid hydrocarbons like gasoline and alcohols, e.g., ethanol as biogenic fuel. The goal is to develop compact systems for generation of hydrogen from fuel being suitable for small-scale membrane fuel cells. The most recent work is related to reforming according to the autothermal principle — fuel, air and steam is supplied to the reactor. Possible applications of such small-scale autothermal reformers are mobile systems and also miniature fuel cell as co-generation plant for decentralised electricity and heat generation. For small stand-alone systems without a connection to the natural gas grid liquid gas, a mixture of propane and butane is an appropriate fuel.

  3. Hydrogen generation, distribution and combustion under severe LWR accident conditions: a state-of-technology report

    International Nuclear Information System (INIS)

    Postma, A.K.; Hilliard, R.K.

    1983-03-01

    This report reviews the current state of technology regarding hydrogen safety issues in light water reactor plants. Topics considered in this report include hydrogen generation, distribution in containment, and combustion characteristics. A companion report addresses hydrogen control. The objectives of the study were to identify the key safety issues related to hydrogen produced under severe accident conditions, to describe the state of technology for each issue, and to point out ongoing programs aimed at resolving the open issues

  4. Hydrogen generation using the modular helium reactor

    International Nuclear Information System (INIS)

    Richards, M.; Shenoy, A.

    2004-01-01

    Process heat from a high-temperature nuclear reactor can be used to drive a set of chemical reactions, with the net result of splitting water into hydrogen and oxygen. For example, process heat at temperatures in the range 850 deg.C to 950 deg.C can drive the sulfur-iodine (SI) thermochemical process to produce hydrogen with high efficiency. Electricity can also be used to split water, using conventional, low-temperature electrolysis. An example of a hybrid process is high-temperature electrolysis (HTE), in which process heat is used to generate steam, which is then supplied to an electrolyser to generate hydrogen. In this paper we investigate the coupling of the Modular Helium Reactor (MHR) to the SI process and HTE. These concepts are referred to as the H2-MHR. Optimization of the MHR core design to produce higher coolant outlet temperatures is also discussed. The use of fixed orifices to control the flow distribution is a promising design solution for increasing the coolant outlet temperature without increasing peak fuel temperatures significantly

  5. Utilization of Aluminum Waste with Hydrogen and Heat Generation

    Science.gov (United States)

    Buryakovskaya, O. A.; Meshkov, E. A.; Vlaskin, M. S.; Shkolnokov, E. I.; Zhuk, A. Z.

    2017-10-01

    A concept of energy generation via hydrogen and heat production from aluminum containing wastes is proposed. The hydrogen obtained by oxidation reaction between aluminum waste and aqueous solutions can be supplied to fuel cells and/or infrared heaters for electricity or heat generation in the region of waste recycling. The heat released during the reaction also can be effectively used. The proposed method of aluminum waste recycling may represent a promising and cost-effective solution in cases when waste transportation to recycling plants involves significant financial losses (e.g. remote areas). Experiments with mechanically dispersed aluminum cans demonstrated that the reaction rate in alkaline solution is high enough for practical use of the oxidation process. In theexperiments aluminum oxidation proceeds without any additional aluminum activation.

  6. Hydrogen storage for mixed wind-nuclear power plants in the context of a hydrogen economy

    International Nuclear Information System (INIS)

    Taljan, Gregor; Fowler, Michael; Canizares, Claudio; Verbic, Gregor

    2008-01-01

    A novel methodology for the economic evaluation of hydrogen production and storage for a mixed wind-nuclear power plant considering some new aspects such as residual heat and oxygen utilization is applied in this work. This analysis is completed in the context of a hydrogen economy and competitive electricity markets. The simulation of the operation of a combined nuclear-wind-hydrogen system is discussed first, where the selling and buying of electricity, the selling of excess hydrogen and oxygen, and the selling of heat are optimized to maximize profit to the energy producer. The simulation is performed in two phases: in a pre-dispatch phase, the system model is optimized to obtain optimal hydrogen charge levels for the given operational horizons. In the second phase, a real-time dispatch is carried out on an hourly basis to optimize the operation of the system as to maximize profits, following the hydrogen storage levels of the pre-dispatch phase. Based on the operation planning and dispatch results, an economic evaluation is performed to determine the feasibility of the proposed scheme for investment purposes; this evaluation is based on calculations of modified internal rates of return and net present values for a realistic scenario. The results of the present studies demonstrate the feasibility of a hydrogen storage and production system with oxygen and heat utilization for existent nuclear and wind power generation facilities. (author)

  7. Hydrogen transfer preventive device in FBR power plant

    International Nuclear Information System (INIS)

    Hoshi, Yuichi.

    1987-01-01

    Purpose: To prevent transfer of hydrogen, etc. in FBR power plant. Constitution: Since H 2 permeates heat conduction pipes in a steam generator, it is necessary to eliminate all of permeation hydrogen, etc. by primary cold traps particularly in the case of saving the intermediate heat exchange. In view of the above, the heat conduction pipes of the steam generator are constituted as a double pipe structure and helium gases are recycled through the gaps thereof and hydrogen traps are disposed to the recycling path. H 2 released into water flowing through the inside of the inner pipe is permeated through the inner pipe and leached into the gap, but the leached H 2 is carried by the helium recycling stream to the hydrogen trap and then the H 2 stream removed with H 2 is returned to the gaps. In this way, the capacity of the primary cold traps disposed in the liquid sodium recycling circuit can be reduced remarkably and the capacity of the purifying device, if an intermediate heat exchanger is disposed, is also reduced to decrease the plant cost. Further, diffusion of deleterious gases from the primary to the secondary circuits can be prevented as well. (Kamimura, M.)

  8. Next generation CANDU plants

    International Nuclear Information System (INIS)

    Hedges, K.R.; Yu, S.K.W.

    1998-01-01

    Future CANDU designs will continue to meet the emerging design and performance requirements expected by the operating utilities. The next generation CANDU products will integrate new technologies into both the product features as well as into the engineering and construction work processes associated with delivering the products. The timely incorporation of advanced design features is the approach adopted for the development of the next generation of CANDU. AECL's current products consist of 700MW Class CANDU 6 and 900 MW Class CANDU 9. Evolutionary improvements are continuing with our CANDU products to enhance their adaptability to meet customers ever increasing need for higher output. Our key product drivers are for improved safety, environmental protection and improved cost effectiveness. Towards these goals we have made excellent progress in Research and Development and our investments are continuing in areas such as fuel channels and passive safety. Our long term focus is utilizing the fuel cycle flexibility of CANDU reactors as part of the long term energy mix

  9. Photocatalysis in Generation of Hydrogen from Water

    KAUST Repository

    Takanabe, Kazuhiro

    2015-04-18

    Solar energy can be converted by utilizing the thermal or photoelectric effects of photons. Concentrated solar power systems utilize thermal energy from the sun by either making steam and then generating power or shifting the chemical equilibrium of a reaction (e.g., water splitting or CO2 reduction) that occurs at extremely high temperatures. The photocatalytic system contains powder photocatalysts. Each photocatalyst particle should collect sufficient photons from the solar flux to cause the required multielectron reactions to occur. The band gap and band edge positions of semiconductors are the most critical parameters for assessing the suitability of photocatalysts for overall water splitting. The most important requirement when selecting photocatalyst materials is the band positions relative to hydrogen and oxygen evolution potentials. For most photocatalysts, surface modification by cocatalysts was found to be essential to achieve overall water splitting.

  10. One Step Hydrogen Generation Through Sorption Enhanced Reforming

    Energy Technology Data Exchange (ETDEWEB)

    Mays, Jeff [Gas Technology Inst., Des Plaines, IL (United States)

    2017-08-03

    One-step hydrogen generation, using Sorption Enhanced Reforming (SER) technology, is an innovative means of providing critical energy and environmental improvements to US manufacturing processes. The Gas Technology Institute (GTI) is developing a Compact Hydrogen Generator (CHG) process, based on SER technology, which successfully integrates previously independent process steps, achieves superior energy efficiency by lowering reaction temperatures, and provides pathways to doubling energy productivity with less environmental pollution. GTI’s prior CHG process development efforts have culminated in an operational pilot plant. During the initial pilot testing, GTI identified two operating risks- 1) catalyst coating with calcium aluminate compounds, 2) limited solids handling of the sorbent. Under this contract GTI evaluated alternative materials (one catalyst and two sorbents) to mitigate both risks. The alternate catalyst met performance targets and did not experience coating with calcium aluminate compounds of any kind. The alternate sorbent materials demonstrated viable operation, with one material enabling a three-fold increase in sorbent flow. The testing also demonstrated operation at 90% of its rated capacity. Lastly, a carbon dioxide co-production study was performed to assess the advantage of the solid phase separation of carbon dioxide- inherent in the CHG process. Approximately 70% lower capital cost is achievable compared to SMR-based hydrogen production with CO2 capture, as well as improved operating costs.

  11. Nanostructured, complex hydride systems for hydrogen generation

    Directory of Open Access Journals (Sweden)

    Robert A. Varin

    2015-02-01

    Full Text Available Complex hydride systems for hydrogen (H2 generation for supplying fuel cells are being reviewed. In the first group, the hydride systems that are capable of generating H2 through a mechanical dehydrogenation phenomenon at the ambient temperature are discussed. There are few quite diverse systems in this group such as lithium alanate (LiAlH4 with the following additives: nanoiron (n-Fe, lithium amide (LiNH2 (a hydride/hydride system and manganese chloride MnCl2 (a hydride/halide system. Another hydride/hydride system consists of lithium amide (LiNH2 and magnesium hydride (MgH2, and finally, there is a LiBH4-FeCl2 (hydride/halide system. These hydride systems are capable of releasing from ~4 to 7 wt.% H2 at the ambient temperature during a reasonably short duration of ball milling. The second group encompasses systems that generate H2 at slightly elevated temperature (up to 100 °C. In this group lithium alanate (LiAlH4 ball milled with the nano-Fe and nano-TiN/TiC/ZrC additives is a prominent system that can relatively quickly generate up to 7 wt.% H2 at 100 °C. The other hydride is manganese borohydride (Mn(BH42 obtained by mechano-chemical activation synthesis (MCAS. In a ball milled (2LiBH4 + MnCl2 nanocomposite, Mn(BH42 co-existing with LiCl can desorb ~4.5 wt.% H2 at 100 °C within a reasonable duration of dehydrogenation. Practical application aspects of hydride systems for H2 generation/storage are also briefly discussed.

  12. Hydrogen generation by metal corrosion in simulated Waste Isolation Pilot Plant environments. Progress report for the period November 1989 through December 1992

    Energy Technology Data Exchange (ETDEWEB)

    Telander, M.R.; Westerman, R.E. [Pacific Northwest Lab., Richland, WA (United States)

    1993-09-01

    The corrosion and gas-generation characteristics of three material types: low-carbon steel (the current waste packaging material for the Waste Isolation Pilot Plant), Cu-base materials, and Ti-base materials were determined in both the liquid and vapor phase of Brine A, a brine representative of an intergranular Salado Formation brine. Test environments included anoxic brine and anoxic brine with overpressures of CO{sub 2}, H{sub 2}S, and H{sub 2}. Low-carbon steel reacted at a slow, measurable rate with anoxic brine, liberating H{sub 2} on an equimolar basis with Fe reacted. Presence of CO{sub 2} caused the initial reaction to proceed more rapidly, but CO{sub 2}-induced passivation stopped the reaction if the CO{sub 2} were present in sufficient quantities. Low-carbon steel immersed in brine with H{sub 2}S showed no reaction, apparently because of passivation of the steel by formation of a protective iron sulfide reaction product. Cu- and Ti-base materials showed essentially no corrosion when exposed to brine and overpressures of N{sub 2}, CO{sub 2}, and H{sub 2}S except for the rapid and complete reaction between Cu-base materials and H{sub 2}S. No significant reaction took place on any material in any environment in the vapor-phase exposures.

  13. Next Generation Geothermal Power Plants

    Energy Technology Data Exchange (ETDEWEB)

    Brugman, John; Hattar, Mai; Nichols, Kenneth; Esaki, Yuri

    1995-09-01

    A number of current and prospective power plant concepts were investigated to evaluate their potential to serve as the basis of the next generation geothermal power plant (NGGPP). The NGGPP has been envisaged as a power plant that would be more cost competitive (than current geothermal power plants) with fossil fuel power plants, would efficiently use resources and mitigate the risk of reservoir under-performance, and minimize or eliminate emission of pollutants and consumption of surface and ground water. Power plant concepts were analyzed using resource characteristics at ten different geothermal sites located in the western United States. Concepts were developed into viable power plant processes, capital costs were estimated and levelized busbar costs determined. Thus, the study results should be considered as useful indicators of the commercial viability of the various power plants concepts that were investigated. Broadly, the different power plant concepts that were analyzed in this study fall into the following categories: commercial binary and flash plants, advanced binary plants, advanced flash plants, flash/binary hybrid plants, and fossil/geothed hybrid plants. Commercial binary plants were evaluated using commercial isobutane as a working fluid; both air-cooling and water-cooling were considered. Advanced binary concepts included cycles using synchronous turbine-generators, cycles with metastable expansion, and cycles utilizing mixtures as working fluids. Dual flash steam plants were used as the model for the commercial flash cycle. The following advanced flash concepts were examined: dual flash with rotary separator turbine, dual flash with steam reheater, dual flash with hot water turbine, and subatmospheric flash. Both dual flash and binary cycles were combined with other cycles to develop a number of hybrid cycles: dual flash binary bottoming cycle, dual flash backpressure turbine binary cycle, dual flash gas turbine cycle, and binary gas turbine

  14. Mitigation of Hydrogen Hazards in Severe Accidents in Nuclear Power Plants

    International Nuclear Information System (INIS)

    2011-07-01

    Consideration of severe accidents in nuclear power plants is an essential component of the defence in depth approach in nuclear safety. Severe accidents have very low probabilities of occurring, but may have significant consequences resulting from the degradation of nuclear fuel. The generation of hydrogen and the risk of hydrogen combustion, as well as other phenomena leading to overpressurization of the reactor containment in case of severe accidents, represent complex safety issues in relation to accident management. The combustion of hydrogen, produced primarily as a result of heated zirconium metal reacting with steam, can create short term overpressure or detonation forces that may exceed the strength of the containment structure. An understanding of these phenomena is crucial for planning and implementing effective accident management measures. Analysis of all the issues relating to hydrogen risk is an important step for any measure that is aimed at the prevention or mitigation of hydrogen combustion in reactor containments. The main objective of this publication is to contribute to the implementation of IAEA Safety Standards, in particular, two IAEA Safety Requirements: Safety of Nuclear Power Plants: Design and Safety of Nuclear Power Plants: Operation. These Requirements publications discuss computational analysis of severe accidents and accident management programmes in nuclear power plants. Specifically with regard to the risk posed by hydrogen in nuclear power reactors, computational analysis of severe accidents considers hydrogen sources, hydrogen distribution, hydrogen combustion and control and mitigation measures for hydrogen, while accident management programmes are aimed at mitigating hydrogen hazards in reactor containments.

  15. 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

  16. Feasibility Study of Hydrogen Production at Existing Nuclear Power Plants

    Energy Technology Data Exchange (ETDEWEB)

    Stephen Schey

    2009-07-01

    Cooperative Agreement DE-FC07-06ID14788 was executed between the U.S. Department of Energy, Electric Transportation Applications, and Idaho National Laboratory to investigate the economics of producing hydrogen by electrolysis using electricity generated by nuclear power. The work under this agreement is divided into the following four tasks: Task 1 – Produce Data and Analyses Task 2 – Economic Analysis of Large-Scale Alkaline Electrolysis Task 3 – Commercial-Scale Hydrogen Production Task 4 – Disseminate Data and Analyses. Reports exist on the prospect that utility companies may benefit from having the option to produce electricity or produce hydrogen, depending on market conditions for both. This study advances that discussion in the affirmative by providing data and suggesting further areas of study. While some reports have identified issues related to licensing hydrogen plants with nuclear plants, this study provides more specifics and could be a resource guide for further study and clarifications. At the same time, this report identifies other area of risks and uncertainties associated with hydrogen production on this scale. Suggestions for further study in some of these topics, including water availability, are included in the report. The goals and objectives of the original project description have been met. Lack of industry design for proton exchange membrane electrolysis hydrogen production facilities of this magnitude was a roadblock for a significant period. However, recent design breakthroughs have made costing this facility much more accurate. In fact, the new design information on proton exchange membrane electrolyzers scaled to the 1 kg of hydrogen per second electrolyzer reduced the model costs from $500 to $100 million. Task 1 was delayed when the original electrolyzer failed at the end of its economic life. However, additional valuable information was obtained when the new electrolyzer was installed. Products developed during this study

  17. Surface generation of negative hydrogen ion beams

    International Nuclear Information System (INIS)

    Bommel, P.J.M. van.

    1984-01-01

    This thesis describes investigations on negative hydrogen ion sources at the ampere level. Formation of H - ions occurs when positive hydrogen ions capture two electrons at metal surfaces. The negative ionization probability of hydrogen at metal surfaces increases strongly with decreasing work function of the surface. The converters used in this study are covered with cesium. Usually there are 'surface plasma sources' in which the hydrogen source plasma interacts with a converter. In this thesis the author concentrates upon investigating a new concept that has converters outside the plasma. In this approach a positive hydrogen ion beam is extracted from the plasma and is subsequently reflected from a low work function converter surface. (Auth.)

  18. Hydrogen plant module (HPM) and vehicle fueled by same.

    Science.gov (United States)

    2011-09-29

    The goal / objective of the project was to design and fabricate hydrogen plant module (HPM) that is capable of producing : hydrogen fuel onboard a vehicle and that obviates one or more of the present issues related to compressed hydrogen fuel : stora...

  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. Scope for solar hydrogen power plants along Indian coasts

    Science.gov (United States)

    Hajra, Debdyut; Mukhopadhyay, Swarnav

    2016-09-01

    Energy is at the core of economic growth and development in the present day world. But relentless and unchecked use of harmful energy resources like fossil fuels (coil and oil), nuclear energy has taken a toll on mother nature. The energy coffers are being rapidly depleted and within a few years all of them will become empty, leaving nothing for the future generations to build on. Their constant usage has degraded the air quality and given way to land and water pollution. Scientists and world leaders have initiated a call for action to shift our dependence from currently popular energy sources to cleaner and renewable energy sources. Search for such energy sources have been going on for many years. Solar energy, wind energy, ocean energy, tidal energy, biofuel, etc. have caught the attention of people. Another such important which has become popular is 'Solar Hydrogen'. Many visionary scientists have called hydrogen the energy of the future. It is produced from water by direct or indirect use of sunlight in a sustainable manner. This paper discusses the current energy scenario, the importance of solar-hydrogen as a fuel and most importantly the scope for solar hydrogen power plants along Indian coastline.

  1. Training for power plant personnel on hydrogen production and control

    International Nuclear Information System (INIS)

    Dickelman, G.J.

    1982-01-01

    It is the purpose of this paper to address the issue of training for power plant personnel in the area of hydrogen control. The authors experience in the training business indicates that most of the operations and engineering personnel have a very limited awareness of this phenomenon. Topics discussed in this paper include: 1) theory of hydrogen combustion kinetics; 2) incidents involving hydrogen combustion events; 3) normal operations interfacing with hydrogen; 4) accident conditions; and 5) mitigation schemes

  2. Liquid-phase chemical hydrogen storage: catalytic hydrogen generation under ambient conditions.

    Science.gov (United States)

    Jiang, Hai-Long; Singh, Sanjay Kumar; Yan, Jun-Min; Zhang, Xin-Bo; Xu, Qiang

    2010-05-25

    There is a demand for a sufficient and sustainable energy supply. Hence, the search for applicable hydrogen storage materials is extremely important owing to the diversified merits of hydrogen energy. Lithium and sodium borohydride, ammonia borane, hydrazine, and formic acid have been extensively investigated as promising hydrogen storage materials based on their relatively high hydrogen content. Significant advances, such as hydrogen generation temperatures and reaction kinetics, have been made in the catalytic hydrolysis of aqueous lithium and sodium borohydride and ammonia borane as well as in the catalytic decomposition of hydrous hydrazine and formic acid. In this Minireview we briefly survey the research progresses in catalytic hydrogen generation from these liquid-phase chemical hydrogen storage materials.

  3. Embedded system based on PWM control of hydrogen generator with SEPIC converter

    Science.gov (United States)

    Fall, Cheikh; Setiawan, Eko; Habibi, Muhammad Afnan; Hodaka, Ichijo

    2017-09-01

    The objective of this paper is to design and to produce a micro electrical plant system based on fuel cell for teaching material-embedded systems in technical vocational training center. Based on this, the student can experience generating hydrogen by fuel cells, controlling the rate of hydrogen generation by the duty ration of single-ended primary-inductor converter(SEPIC), drawing the curve rate of hydrogen to duty ratio, generating electrical power by using hydrogen, and calculating the fuel cell efficiency when it is used as electrical energy generator. This project is of great importance insofar as students will need to acquire several skills to be able to realize it such as continuous DC DC conversion and the scientific concept behind the converter, the regulation of systems with integral proportional controllers, the installation of photovoltaic cells, the use of high-tech sensors, microcontroller programming, object-oriented programming, mastery of the fuel cell syste

  4. 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.

  5. Hydrogen Generation from Sugars via Aqueous-Phase Reforming

    International Nuclear Information System (INIS)

    Randy D Cortright

    2006-01-01

    Virent Energy Systems, Inc. is commercializing the Aqueous Phase Reforming (APR) process that allows the generation of hydrogen-rich gas streams from biomass-derived compounds such as glycerol, sugars, and sugar alcohols. The APR process is a unique method that generates hydrogen from aqueous solutions of these oxygenated compounds in a single step reactor process compared to the three or more reaction steps required for hydrogen generation via conventional processes that utilize non-renewable fossil fuels. The key breakthrough of the APR process is that the reforming of these aqueous solutions is done in the liquid phase. The patented APR process occurs at temperatures (150 C to 270 C) where the water-gas shift reaction is favorable, making it possible to generate hydrogen with low amounts of CO in a single chemical reactor. Furthermore, the APR process occurs at pressures (typically 15 to 50 bar) where the hydrogen-rich effluent can be effectively purified using either membrane technology or pressure swing adsorption technology. The utilization of biomass-based compounds allows the APR process to be a carbon neutral method to generate hydrogen. In the near term, the feed-stock of interest is waste glycerol that is being generated in large quantities as a byproduct in the production of bio-diesel. Virent has developed the APR system for on-demand generation of hydrogen-rich fuel gas from either glycerol or sorbitol (the sugar alcohol formed by hydrogenation of glucose) to fuel a stationary internal combustion engine driven generator (10 kW). Under a USDOE funded project, Virent is currently developing the APR process to generate high yields of hydrogen from corn-derived glucose. This project objective is to achieve the DOE 2010 cost target for distributed production from renewable liquid fuels of 3.60 dollars/gge (gasoline gallon equivalent) delivered. (authors)

  6. A self-regulating hydrogen generator for micro fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Moghaddam, Saeed; Pengwang, Eakkachai; Shannon, Mark A. [Mechanical Science and Engineering, University of Illinois at Urbana-Champaign, 1206 West Green Street, Urbana, IL 61801 (United States); Masel, Richard I. [Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, 213 Roger Adams Lab, 600 S. Mathews, Urbana, IL 61801 (United States)

    2008-10-15

    The ever-increasing power demands and miniaturization of portable electronics, micro-sensors and actuators, and emerging technologies such as cognitive arthropods have created a significant interest in development of micro fuel cells. One of the major challenges in development of hydrogen micro fuel cells is the fabrication and integration of auxiliary systems for generating, regulating, and delivering hydrogen gas to the membrane electrode assembly (MEA). In this paper, we report the development of a hydrogen gas generator with a micro-scale control system that does not consume any power. The hydrogen generator consists of a hydride reactor and a water reservoir, with a regulating valve separating them. The regulating valve consists of a port from the water reservoir and a movable membrane with via holes that permit water to flow from the reservoir to the hydride reactor. Water flows towards the hydride reactor, but stops within the membrane via holes due to capillary forces. Water vapor then diffuses from the via holes into the hydride reactor resulting in generation of hydrogen gas. When the rate of hydrogen consumed by the MEA is lower than the generation rate, gas pressure builds up inside the hydride reactor, deflecting the membrane, closing the water regulator valve, until the pressure drops, whereby the valve reopens. We have integrated the self-regulating micro hydrogen generator to a MEA and successfully conducted fuel cell tests under varying load conditions. (author)

  7. How to optimize hydrogen plant designs

    Energy Technology Data Exchange (ETDEWEB)

    van Weenen, W F; Tielrooy, J

    1983-01-01

    In a typical hydrogen plant of the type which will be discussed, methane or higher hydrocarbons are reformed with steam in a steam hydrocarbon reformer operating at a pressure of 250 to 400 psig, a temperature of 1500 to 1600/sup 0/F, and with a ratio of steam to carbon in the feed of about 3.0. Following the reformer and cooling, there is a single stage of high temperature carbon monoxide shift conversion. Optionally, after further cooling, this may be followed by a second stage of carbon monoxide shift conversion operating at a lower temperature to obtain a more favourable equilibrium; this is called low temperature shift conversion. After cooling to ambient temperature, and separation of the condensate, the gas is passed through a Pressure Swing Adsorption (PSA)l unit which removes all the impurities along with a small amount of hydrogen. The waste gas from the PSA unit containing all the impurities is used as fuel to the reformer. Heat is recovered from the reformer flue gas, reformer product, high temperature shift converter product and low temperature shift converter product. This paper discusses some of the process variables and design variables which must be considered in arriving at an optimized design. Seven different flow schemes are discussed in the light of the objectives they are designed for. The seven schemes and their objectives are: Flow Scheme 1 - lowest first cost; moderate efficiency, Flow Scheme 2 - high efficiency, low cost; Flow Scheme 3 - low feed plus fuel, moderately high efficiency; Flow Scheme 4 - lowest feed plus fuel; Flow Scheme 5 - lowest feed, low fuel; Flow Scheme 6 -lowest feed, highest efficiency; and Flow Scheme 7 - lowest feed plus fuel, export electric power instead of export electric power instead of export steam. 15 figures, 1 table.

  8. 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

  9. Preliminary analyses on hydrogen diffusion through small break of thermo-chemical IS process hydrogen plant

    International Nuclear Information System (INIS)

    Somolova, Marketa; Terada, Atsuhiko; Takegami, Hiroaki; Iwatsuki, Jin

    2008-12-01

    Japan Atomic Energy Agency has been conducting a conceptual design study of nuclear hydrogen demonstration plant, that is, a thermal-chemical IS process hydrogen plant coupled with the High temperature Engineering Test Reactor (HTTR-IS), which will be planed to produce a large amount of hydrogen up to 1000m 3 /h. As part of the conceptual design work of the HTTR-IS system, preliminary analyses on small break of a hydrogen pipeline in the IS process hydrogen plant was carried out as a first step of the safety analyses. This report presents analytical results of hydrogen diffusion behaviors predicted with a CFD code, in which a diffusion model focused on the turbulent Schmidt number was incorporated. By modifying diffusion model, especially a constant accompanying the turbulent Schmidt number in the diffusion term, analytical results was made agreed well with the experimental results. (author)

  10. Next Generation Nuclear Plant Materials Research and Development Program Plan

    Energy Technology Data Exchange (ETDEWEB)

    G. O. Hayner; E.L. Shaber

    2004-09-01

    The U.S Department of Energy (DOE) has selected the Very High Temperature Reactor (VHTR) design for the Next Generation Nuclear Plant (NGNP) Project. The NGNP will demonstrate the use of nuclear power for electricity and hydrogen production without greenhouse gas emissions. The reactor design will be a graphite moderated, helium-cooled, prismatic or pebble-bed, thermal neutron spectrum reactor that will produce electricity and hydrogen in a state-of-the-art thermodynamically efficient manner. The NGNP will use very high burn-up, low-enriched uranium, TRISO-coated fuel and have a projected plant design service life of 60 years.

  11. Thermochemical hydrogen generation of indium oxide thin films

    Directory of Open Access Journals (Sweden)

    Taekyung Lim

    2017-03-01

    Full Text Available Development of alternative energy resources is an urgent requirement to alleviate current energy constraints. As such, hydrogen gas is gaining attention as a future alternative energy source to address existing issues related to limited energy resources and air pollution. In this study, hydrogen generation by a thermochemical water-splitting process using two types of In2O3 thin films was investigated. The two In2O3 thin films prepared by chemical vapor deposition (CVD and sputtering deposition systems contained different numbers of oxygen vacancies, which were directly related to hydrogen generation. The as-grown In2O3 thin film prepared by CVD generated a large amount of hydrogen because of its abundant oxygen vacancies, while that prepared by sputtering had few oxygen vacancies, resulting in low hydrogen generation. Increasing the temperature of the In2O3 thin film in the reaction chamber caused an increase in hydrogen generation. The oxygen-vacancy-rich In2O3 thin film is expected to provide a highly effective production of hydrogen as a sustainable and efficient energy source.

  12. Hydrogen generator from light hydrocarbons for stationary applications

    International Nuclear Information System (INIS)

    Cipiti, F.; Recupero, Vincenzo; Pino, L.; Vita, A.; Lagana, M.

    2006-01-01

    The present article describes the activities carried out in the CNR institute, particularly the development, realization and testing of one unit of hydrogen generation to integrate with fuel-cells for residential applications [it

  13. Cold weather hydrogen generation system and method of operation

    Science.gov (United States)

    Dreier, Ken Wayne; Kowalski, Michael Thomas; Porter, Stephen Charles; Chow, Oscar Ken; Borland, Nicholas Paul; Goyette, Stephen Arthur

    2010-12-14

    A system for providing hydrogen gas is provided. The system includes a hydrogen generator that produces gas from water. One or more heat generation devices are arranged to provide heating of the enclosure during different modes of operation to prevent freezing of components. A plurality of temperature sensors are arranged and coupled to a controller to selectively activate a heat source if the temperature of the component is less than a predetermined temperature.

  14. Containment hydrogen removal system for a nuclear power plant

    International Nuclear Information System (INIS)

    Callaghan, V.M.; Flynn, E.P.; Pokora, B.M.

    1984-01-01

    A hydrogen removal system (10) separates hydrogen from the containment atmosphere of a nuclear power plant using a hydrogen permeable membrane separator (30). Water vapor is removed by condenser (14) from a gas stream withdrawn from the containment atmosphere. The gas stream is then compressed by compressor (24) and cooled (28,34) to the operating temperature of the hydrogen permeable membrane separator (30). The separator (30) separates the gas stream into a first stream, rich in hydrogen permeate, and a second stream that is hydrogen depleted. The separated hydrogen is passed through a charcoal adsorber (48) to adsorb radioactive particles that have passed through the hydrogen permeable membrane (44). The hydrogen is then flared in gas burner (52) with atmospheric air and the combustion products vented to the plant vent. The hydrogen depleted stream is returned to containment through a regenerative heat exchanger (28) and expander (60). Energy is extracted from the expander (60) to drive the compressor (24) thereby reducing the energy input necessary to drive the compressor (24) and thus reducing the hydrogen removal system (10) power requirements

  15. Hydrolysis Batteries: Generating Electrical Energy during Hydrogen Absorption.

    Science.gov (United States)

    Xiao, Rui; Chen, Jun; Fu, Kai; Zheng, Xinyao; Wang, Teng; Zheng, Jie; Li, Xingguo

    2018-02-19

    The hydrolysis reaction of aluminum can be decoupled into a battery by pairing an Al foil with a Pd-capped yttrium dihydride (YH 2 -Pd) electrode. This hydrolysis battery generates a voltage around 0.45 V and leads to hydrogen absorption into the YH 2 layer. This represents a new hydrogen absorption mechanism featuring electrical energy generation during hydrogen absorption. The hydrolysis battery converts 8-15 % of the thermal energy of the hydrolysis reaction into usable electrical energy, leading to much higher energy efficiency compared to that of direct hydrolysis. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Autonomous hydrogen power plants with renewable energy sources

    International Nuclear Information System (INIS)

    Popel', O.S.; Frid, S.E.; Shpil'rajn, Eh.Eh.; Izosimov, D.B.; Tumanov, V.L.

    2006-01-01

    One studies the principles to design independent hydrogen power plants (IHPP) operating on renewable energy sources and the approaches to design a pilot IHP plant. One worded tasks of mathematical simulation and of calculations to substantiate the optimal configuration of the mentioned plants depending on the ambient conditions of operation and on peculiar features of a consumer [ru

  17. Low-level hydrogen peroxide generation by unbleached cotton nonwovens: implications for wound healing applications

    Science.gov (United States)

    Greige cotton is an intact plant fiber. The cuticle and primary cell wall near the outer surface of the cotton fiber contains pectin, peroxidases, superoxide dismutase (SOD), and trace metals, which are associated with hydrogen peroxide (H2O2) generation during cotton fiber development. The compon...

  18. Hydrogen embrittlement in power plant steels

    Indian Academy of Sciences (India)

    M. Senthilkumar (Newgen Imaging) 1461 1996 Oct 15 13:05:22

    cause of blistering is well-known, handling and finishing techniques have been developed to minimize this form of damage. Vacuum melting and degassing minimize the quantity of hydrogen in the steels. Acid pickling and other such processes that may introduce hydrogen are avoided when practical, and possible moisture ...

  19. IEA Hydrogen Implementing Agreement's Second Generation R and D and the Hydrogen Economy

    Energy Technology Data Exchange (ETDEWEB)

    Beck, N.; Garcia-Conde, A. G.; Riis, T. U.; Luzzi, A.; Valladares, M. R. de

    2005-07-01

    Since its creation by the International Energy Agency in the late 1970's, the IEA Hydrogen Implementing Agreement (HIA) has been at the forefront of collaborative international hydrogen research and development (R and D) (http://www.ieahia.org. ) The collective body of HIA hydrogen R and D will contribute to definition of the hydrogen economy. The five-year [2004-2009) mission of the IEA HIA is to advance the adoption of a Hydrogen Economy through strategic implementation of collaborative R and D and outreach programs that address key issues and barriers. The three goals for the Second Generation HIA are: Advancement of science and technology via pre-commercial collaborative RD and D programs; Assessment of market environment, including the non-energy sector; and Implementation of outreach program, aimed at community acceptance and support. The HIA launched its Second Generation of hydrogen R and D in the latter part of 2004. The HIA's anniversary report: In Pursuit of the Future: 25 Years of IEA Research towards the realization of Hydrogen Energy Systems (http://ieahia.org/pdfs/IEA_AnniversaryReport_HIA.pdf) chronicles its contributions to hydrogen R and D. As the hydrogen economy takes shape, the HIA is pleased to share highlights of its R and D history together with progress on planned activities and its six current annexes, listed below: Task 15 Photobiological Production of Hydrogen Task 16 Hydrogen from Carbon-Containing Materials Task 17 Solid and Liquid Storage Task 18 Integrated Systems Evaluation Task 19 Safety Task 20 Hydrogen from Waterphotolysis Planned successor annexes in storage and photobiological hydrogen production will also be discussed, along with a task on high temperature hydrogen production that is now in the definition phase. Over 250 experts from the sixteen member HIA countries and the European Union contribute to this portfolio of cutting edge hydrogen R and D and analysis activities. Several other countries are expected to

  20. Hydrogen generation at ambient conditions: application in fuel cells.

    Science.gov (United States)

    Boddien, Albert; Loges, Björn; Junge, Henrik; Beller, Matthias

    2008-01-01

    The efficient generation of hydrogen from formic acid/amine adducts at ambient temperature is demonstrated. The highest catalytic activity (TOF up to 3630 h(-1) after 20 min) was observed in the presence of in situ generated ruthenium phosphine catalysts. Compared to the previously known methods to generate hydrogen from liquid feedstocks, the systems presented here can be operated at room temperature without the need for any high-temperature reforming processes, and the hydrogen produced can then be directly used in fuel cells. A variety of Ru precursors and phosphine ligands were investigated for the decomposition of formic acid/amine adducts. These catalytic systems are particularly interesting for the generation of H2 for new applications in portable electric devices.

  1. Next Generation Nuclear Plant GAP Analysis Report

    Energy Technology Data Exchange (ETDEWEB)

    Ball, Sydney J [ORNL; Burchell, Timothy D [ORNL; Corwin, William R [ORNL; Fisher, Stephen Eugene [ORNL; Forsberg, Charles W. [Massachusetts Institute of Technology (MIT); Morris, Robert Noel [ORNL; Moses, David Lewis [ORNL

    2008-12-01

    As a follow-up to the phenomena identification and ranking table (PIRT) studies conducted recently by NRC on next generation nuclear plant (NGNP) safety, a study was conducted to identify the significant 'gaps' between what is needed and what is already available to adequately assess NGNP safety characteristics. The PIRT studies focused on identifying important phenomena affecting NGNP plant behavior, while the gap study gives more attention to off-normal behavior, uncertainties, and event probabilities under both normal operation and postulated accident conditions. Hence, this process also involved incorporating more detailed evaluations of accident sequences and risk assessments. This study considers thermal-fluid and neutronic behavior under both normal and postulated accident conditions, fission product transport (FPT), high-temperature metals, and graphite behavior and their effects on safety. In addition, safety issues related to coupling process heat (hydrogen production) systems to the reactor are addressed, given the limited design information currently available. Recommendations for further study, including analytical methods development and experimental needs, are presented as appropriate in each of these areas.

  2. Hydrogen-oxygen steam generator applications for increasing the efficiency, maneuverability and reliability of power production

    Science.gov (United States)

    Schastlivtsev, A. I.; Borzenko, V. I.

    2017-11-01

    The comparative feasibility study of the energy storage technologies showed good applicability of hydrogen-oxygen steam generators (HOSG) based energy storage systems with large-scale hydrogen production. The developed scheme solutions for the use of HOSGs for thermal power (TPP) and nuclear power plants (NPP), and the feasibility analysis that have been carried out have shown that their use makes it possible to increase the maneuverability of steam turbines and provide backup power supply in the event of failure of the main steam generating equipment. The main design solutions for the integration of hydrogen-oxygen steam generators into the main power equipment of TPPs and NPPs, as well as their optimal operation modes, are considered.

  3. Thermal integration of SCWR nuclear and thermochemical hydrogen plants

    International Nuclear Information System (INIS)

    Wang, Z.; Naterer, G.F.; Gabriel, K.S.

    2010-01-01

    In this paper, the intermediate heat exchange between a Generation IV supercritical water-cooled nuclear reactor (SCWR) and a thermochemical hydrogen production cycle is discussed. It is found that the maximum and range of temperatures of a thermochemical cycle are the dominant parameters that affect the design of its coupling with SCWR. The copper-chlorine (Cu-Cl) thermochemical cycle is a promising cycle that can link with SCWRs. The location of extracting heat from a SCWR to a thermochemical cycle is investigated in this paper. Steam bypass lines downstream of the SCWR core are suggested for supplying heat to the Cu-Cl hydrogen production cycle. The stream extraction location is strongly dependent on the temperature requirements of the chemical steps of the thermochemical cycle. The available quantity of heat exchange at different hours of a day is also studied. It is found that the available heat at most hours of power demand in a day can support an industrial scale steam methane reforming plant if the SCWR power station is operating at full design capacity. (author)

  4. Molecular cobalt pentapyridine catalysts for generating hydrogen from water

    Science.gov (United States)

    Long, Jeffrey R; Chang, Christopher J; Sun, Yujie

    2013-11-05

    A composition of matter suitable for the generation of hydrogen from water is described, the positively charged cation of the composition including the moiety of the general formula. [(PY5Me.sub.2)CoL].sup.2+, where L can be H.sub.2O, OH.sup.-, a halide, alcohol, ether, amine, and the like. In embodiments of the invention, water, such as tap water or sea water can be subject to low electric potentials, with the result being, among other things, the generation of hydrogen.

  5. Lessons learned from hydrogen generation and burning during the TMI-2 event

    International Nuclear Information System (INIS)

    Henrie, J.O.; Postma, A.K.

    1987-05-01

    This document summarizes what has been learned from generation of hydrogen in the reactor core and the hydrogen burn that occurred in the containment building of the Three Mile Island Unit No. 2 (TMI-2) nuclear power plant on March 28, 1979. During the TMI-2 loss-of-coolant accident (LOCA), a large quantity of hydrogen was generated by a zirconium-water reaction. The hydrogen burn that occurred 9 h and 50 min after the initiation of the TMI-2 accident went essentially unnoticed for the first few days. Even through the burn increased the containment gas temperature and pressure to 1200 0 F (650 0 C) and 29 lb/in 2 (200 kPa) gage, there was no serious threat to the containment building. The processes, rates, and quantities of hydrogen gas generated and removed during and following the LOCA are described in this report. In addition, the methods which were used to define the conditions that existed in the containment building before, during, and after the hydrogen burn are described. The results of data evaluations and engineering calculations are presented to show the pressure and temperature histories of the atmosphere in various containment segments during and after the burn. Material and equipment in reactor containment buildings can be protected from burn damage by the use of relatively simple enclosures or insulation

  6. Electrokinetic Hydrogen Generation from Liquid WaterMicrojets

    Energy Technology Data Exchange (ETDEWEB)

    Duffin, Andrew M.; Saykally, Richard J.

    2007-05-31

    We describe a method for generating molecular hydrogen directly from the charge separation effected via rapid flow of liquid water through a metal orifice, wherein the input energy is the hydrostatic pressure times the volume flow rate. Both electrokinetic currents and hydrogen production rates are shown to follow simple equations derived from the overlap of the fluid velocity gradient and the anisotropic charge distribution resulting from selective adsorption of hydroxide ions to the nozzle surface. Pressure-driven fluid flow shears away the charge balancing hydronium ions from the diffuse double layer and carries them out of the aperture. Downstream neutralization of the excess protons at a grounded target electrode produces gaseous hydrogen molecules. The hydrogen production efficiency is currently very low (ca. 10-6) for a single cylindrical jet, but can be improved with design changes.

  7. Prediction of hydrogen distribution in the reactor building in CANDU6 plant

    International Nuclear Information System (INIS)

    Jin, Y.; Song, Y.

    2008-01-01

    The CANDU plants have a lot of zircaloy. The fuel cladding, calandria tubes and pressure tubes are made of zircaloy. The zircaloy can be oxidized and hydrogen is generated during severe accident progression. The detonation or deflagration to detonation transition (DDT) due to hydrogen combustion may occur if the local hydrogen concentration or global hydrogen concentration exceeds certain value. The detonation may result in the rupture of the reactor building. The inside of the reactor building of CANDU plants is complex. So prediction of hydrogen distribution in the reactor building is important. This prediction is made using ISAAC code and GOTHIC code. ISAAC code partitioned the reactor building in to 7 compartments. GOTHIC code modeled the CANDU6 reactor building using 12 nodes. The hydrogen concentrations in the various compartments in the reactor building are compared. GOTHIC code slightly underpredicts hydrogen concentration in the F/M rooms than ISAAC code, but trend is same. The hydrogen concentration in the boiler room and the moderator room shows almost same as for both codes. (author)

  8. VHTR-based Nuclear Hydrogen Plant Analysis for Hydrogen Production with SI, HyS, and HTSE Facilities

    International Nuclear Information System (INIS)

    Shin, Youngjoon; Lee, Taehoon; Lee, Kiyoung; Kim, Minhwan

    2016-01-01

    In this paper, analyses of material and heat balances on the SI, HyS, and HTSE processes coupled to a Very High Temperature gas-cooled Reactor (VHTR) were performed. The hydrogen production efficiency including the thermal to electric energy ratio demanded from each process is found and the normalized evaluation results obtained from three processes are compared to each other. The currently technological issues to maintain the long term continuous operation of each process will be discussed at the conference site. VHTR-based nuclear hydrogen plant analysis for hydrogen production with SI, HyS, and HTSE facilities has been carried out to determine the thermal efficiency. It is evident that the thermal to electrical energy ratio demanded from each hydrogen production process is an important parameter to select the adequate process for hydrogen production. To improve the hydrogen production efficiency in the SI process coupled to the VHTR without electrical power generation, the demand of electrical energy in the SI process should be minimized by eliminating an electrodialysis step to break through the azeotrope of the HI/I_2/H_2O ternary aqueous solution

  9. Modeling of hydrogen behaviour in a PWR nuclear power plant containment with the CONTAIN code

    International Nuclear Information System (INIS)

    Bobovnik, G.; Kljenak, I.

    2001-01-01

    Hydrogen behavior in the containment during a severe accident in a two-loop Westinghouse-type PWR nuclear power plant was simulated with the CONTAIN code. The accident was initiated with a cold-leg break of the reactor coolant system in a steam generator compartment. In the input model, the containment is represented with 34 cells. Beside hydrogen concentration, the containment atmosphere temperature and pressure and the carbon monoxide concentration were observed as well. Simulations were carried out for two different scenarios: with and without successful actuation of the containment spray system. The highest hydrogen concentration occurs in the containment dome and near the hydrogen release location in the early stages of the accident. Containment sprays do not have a significant effect on hydrogen stratification.(author)

  10. Some hydrogen-control considerations for ice-condenser nuclear plants

    International Nuclear Information System (INIS)

    Hubbard, H.W.; Hammond, R.P.; Zivi, S.M.

    1981-02-01

    The proposal of the Tennessee Valley Authority (TVA) for coping with the problem of accident generated hydrogen gas in its Sequoyah ice-condenser plant was to put in place glow-plug igniters so that any hydrogen that is evolved during an accident could be burnt before accumulating into a dangerously large mass. Since it was desired to install these igniters in the Sequoyah and other plants as quickly as possible, the NRC asked the Lawrence Livermore National Laboratory (LLNL) to carry out some experiments on these igniters to delineate the region of their applicability

  11. Correlation energy generating potentials for molecular hydrogen

    International Nuclear Information System (INIS)

    Sharma, B.S.; Thakkar, A.J.

    1985-01-01

    A variety of local correlation energy functionals are currently in use. All of them depend, to some extent, on modeling the correlation energy of a homogeneous electron fluid. Since atomic and molecular charge densities are neither uniform nor slowly varying, it is important to attempt to use known high accuracy wave functions to learn about correlation energy functionals appropriate to such systems. We have extended the definition of the correlation energy generating potentials V/sub c/ introduced by Ros. A charge density response to correlation has been allowed for by inclusion of an electron--nuclear component V/sup e/n/sub c/ in addition to the electron--electron component V/sup e/e/sub c/. Two different definitions of V/sup e/n/sub c/ are given. We present the first calculations of V/sub c/ for a molecular system: H 2 . The results show that V/sup e/n/sub c/, in either definition, is by no means negligible. Moreover, V/sup e/e/sub c/ and both forms of V/sup e/n/sub c/ show significant nonlocal dependence on the charge density. Calculations with ten different model correlation energy functionals show that none of them is particularly sensitive to the charge density. However, they are quite sensitive to the parametrization of the electron fluid correlation energy. The schemes which include self-interaction corrections (SIC) are found to be superior to those of Kohn--Sham type. The correlation energy generating potentials implied by the SIC type and empirical correlation energy functionals are found to correspond roughly to averages of one of the accurate potentials

  12. Review of Design Data for Safety Assessment of Tokai Reprocessing Plant. Control of hydrogen gas produced by radiolysis of reprocessing solutions at Tokai Reprocessing Plant

    International Nuclear Information System (INIS)

    Omori, E.; Surugaya, N.; Takaya, A.; Nakamura, H.; Maki, A.; Yamanouchi, T.

    1999-10-01

    Radioactive materials in aqueous solution at a nuclear fuel reprocessing plant causes radiolytic generation of several gases including hydrogen. Hydrogen accumulating in equipment can be an explosion hazard. In such plants, though the consideration in the design has been fundamentally made in order to remove the ignition source from the equipment, the hydrogen concentration in the equipment should not exceed the explosion threshold. It is, therefore, desired to keep the hydrogen concentration lower than the explosion threshold by dilution with the air introduced into equipment, from the viewpoint which previously prevents the explosion. This report describes the calculation of hydrogen generation, evaluation of hydrogen concentration under abnormal operation and consideration of possible improvement at Tokai Reprocessing Plant. The amount of hydrogen generation was calculated for each equipment from available data on radiolysis induced by radioactive materials. Taking into consideration for abnormal condition that is single failure of air supply and loss of power supply, the investigation was made on the method for controlling so that the hydrogen concentration may not exceed the explosion threshold. Possible means which can control the concentration of hydrogen gas under the explosion threshold have been also investigated. As the result, it was found that hydrogen concentration of most equipment was kept under the explosion threshold. It was also shown that improvement of the facility was necessary on the equipment in which the concentration of the hydrogen may exceed the explosion threshold. Proposals based on the above results are also given in this report. The above content has been described in 'Examination of the hydrogen produced by the radiolysis' which is a part of 'Reviews of Design Data for Safety Assessment of Tokai Reprocessing Plant' (JNC TN8410 99-002) published in February 1999. This report incorporates the detail evaluation so that operation

  13. Utilization of hydrogen gas production for electricity generation in ...

    African Journals Online (AJOL)

    Utilization of hydrogen gas production for electricity generation in fuel cell by Enterobacter aerogenes ADH 43 with many kinds of carbon sources in batch stirred tank reactor. MA Rachman, LD Eniya, Y Liasari, MM Nasef, A Ahmad, H Saidi ...

  14. Extreme hydrogen plasma densities achieved in a linear plasma generator

    NARCIS (Netherlands)

    Rooij, van G.J.; Veremiyenko, V.P.; Goedheer, W.J.; Groot, de B.; Kleyn, A.W.; Smeets, P.H.M.; Versloot, T.W.; Whyte, D.G.; Engeln, R.A.H.; Schram, D.C.; Lopes Cardozo, N.J.

    2007-01-01

    A magnetized hydrogen plasma beam was generated with a cascaded arc, expanding in a vacuum vessel at an axial magnetic field of up to 1.6 T. Its characteristics were measured at a distance of 4 cm from the nozzle: up to a 2 cm beam diameter, 7.5×1020 m-3 electron density, ~2 eV electron and ion

  15. Method for generating hydrogen for fuel cells

    Science.gov (United States)

    Ahmed, Shabbir; Lee, Sheldon H. D.; Carter, John David; Krumpelt, Michael

    2004-03-30

    A method of producing a H.sub.2 rich gas stream includes supplying an O.sub.2 rich gas, steam, and fuel to an inner reforming zone of a fuel processor that includes a partial oxidation catalyst and a steam reforming catalyst or a combined partial oxidation and stream reforming catalyst. The method also includes contacting the O.sub.2 rich gas, steam, and fuel with the partial oxidation catalyst and the steam reforming catalyst or the combined partial oxidation and stream reforming catalyst in the inner reforming zone to generate a hot reformate stream. The method still further includes cooling the hot reformate stream in a cooling zone to produce a cooled reformate stream. Additionally, the method includes removing sulfur-containing compounds from the cooled reformate stream by contacting the cooled reformate stream with a sulfur removal agent. The method still further includes contacting the cooled reformate stream with a catalyst that converts water and carbon monoxide to carbon dioxide and H.sub.2 in a water-gas-shift zone to produce a final reformate stream in the fuel processor.

  16. Dealloyed Ruthenium Film Catalysts for Hydrogen Generation from Chemical Hydrides

    Directory of Open Access Journals (Sweden)

    Ramis B. Serin

    2017-07-01

    Full Text Available Thin-film ruthenium (Ru and copper (Cu binary alloys have been prepared on a Teflon™ backing layer by cosputtering of the precious and nonprecious metals, respectively. Alloys were then selectively dealloyed by sulfuric acid as an etchant, and their hydrogen generation catalysts performances were evaluated. Sputtering time and power of Cu atoms have been varied in order to tailor the hydrogen generation performances. Similarly, dealloying time and the sulfuric acid concentration have also been altered to tune the morphologies of the resulted films. A maximum hydrogen generation rate of 35 mL min−1 was achieved when Cu sputtering power and time were 200 W and 60 min and while acid concentration and dealloying time were 18 M and 90 min, respectively. It has also been demonstrated that the Ru content in the alloy after dealloying gradually increased with the increasing the sputtering power of Cu. After 90 min dealloying, the Ru to Cu ratio increased to about 190 times that of bare alloy. This is the key issue for observing higher catalytic activity. Interestingly, we have also presented template-free nanoforest-like structure formation within the context of one-step alloying and dealloying used in this study. Last but not least, the long-time hydrogen generation performances of the catalysts system have also been evaluated along 3600 min. During the first 600 min, the catalytic activity was quite stable, while about 24% of the catalytic activity decayed after 3000 min, which still makes these systems available for the development of robust catalyst systems in the area of hydrogen generation.

  17. Tritiated hydrogen gas storage systems for a fusion plant

    International Nuclear Information System (INIS)

    Bramy, W.; Hircq, B.; Peyrat, M.; Leger, D.

    1992-01-01

    This paper reports that USSI INGENIERIE has carried out a study financed by European Communities Commission concerning the NET/ITER project, on tritium Fuel Management and Storage systems of the International Thermonuclear Experimental Reactor. A processing block diagram for hydrogen isotopes represents all interfaces and possible links between these systems and tritiated gas mixtures flowing through the Fusion plant. Large quantities of hydrogen isotopes (up to several thousand moles of protium, deuterium and tritium) in gaseous form associated with torus fuelling and exhaust pellet injection, and neutral beam injection, must be stored and managed in such a plant

  18. Hydrogen generation utilizing integrated CO2 removal with steam reforming

    Science.gov (United States)

    Duraiswamy, Kandaswamy; Chellappa, Anand S

    2013-07-23

    A steam reformer may comprise fluid inlet and outlet connections and have a substantially cylindrical geometry divided into reforming segments and reforming compartments extending longitudinally within the reformer, each being in fluid communication. With the fluid inlets and outlets. Further, methods for generating hydrogen may comprise steam reformation and material adsorption in one operation followed by regeneration of adsorbers in another operation. Cathode off-gas from a fuel cell may be used to regenerate and sweep the adsorbers, and the operations may cycle among a plurality of adsorption enhanced reformers to provide a continuous flow of hydrogen.

  19. Generating para-water from para-hydrogen: A Gedankenexperiment.

    Science.gov (United States)

    Ivanov, Konstantin L; Bodenhausen, Geoffrey

    2018-07-01

    A novel conceptual approach is described that is based on the transfer of hyperpolarization from para-hydrogen in view of generating a population imbalance between the two spin isomers of H 2 O. The approach is analogous to SABRE (Signal Amplification By Reversible Exchange) and makes use of the transfer of spin order from para-hydrogen to H 2 O in a hypothetical organometallic complex. The spin order transfer is expected to be most efficient at avoided level crossings. The highest achievable enrichment levels of para- and ortho-water are discussed. Copyright © 2018 Elsevier Inc. All rights reserved.

  20. Wind energy-hydrogen storage hybrid power generation

    Energy Technology Data Exchange (ETDEWEB)

    Wenjei Yang; Orhan Aydin [University of Michigan, Ann Arbor, MI (United States). Dept. of Mechanical Engineering and Applied Mechanics

    2001-07-01

    In this theoretical investigation, a hybrid power generation system utilizing wind energy and hydrogen storage is presented. Firstly, the available wind energy is determined, which is followed by evaluating the efficiency of the wind energy conversion system. A revised model of windmill is proposed from which wind power density and electric power output are determined. When the load demand is less than the output of the generation, the excess electric power is relayed to the electrolytic cell where it is used to electrolyse the de-ionized water. Hydrogen thus produced can be stored as hydrogen compressed gas or liquid. Once the hydrogen is stored in an appropriate high-pressure vessel, it can be used in a combustion engine, fuel cell, or burned in a water-cooled burner to produce a very high-quality steam for space heating, or to drive a turbine to generate electric power. It can also be combined with organic materials to produce synthetic fuels. The conclusion is that the system produces no harmful waste and depletes no resources. Note that this system also works well with a solar collector instead of a windmill. (author)

  1. Perspectives for generation companies and the emerging hydrogen economy

    International Nuclear Information System (INIS)

    Cowan, N.

    2004-01-01

    'Full text:' Canadian and global power generation supply is evolving towards inclusion of emerging types of technologies for electricity production. Although much of Canadian electricity supply will continue to be derived from traditional sources in the foreseeable future the band for capital cost competitiveness is narrowing between the once clear-cut technological winners and emerging generation technologies creating opportunity for new technologies to commercialize in the market. OPG has been active in the development and commercialization of stationary high temperature fuel cells for several years. The major activity has been a partnering initiative to engineer and implement Solid Oxide Fuel Cell (SOFC) demonstration installations. The relationship with SOFC developer Siemens-Westinghouse out of Pittsburgh has allowed OPG to maintain an ongoing involvement in the emerging fuel cell industry, while exploring the broader implications of this technology for the power industry business model. OPG is part of the 'Hydrogen Village Partnership'. The Hydrogen Village will demonstrate and deploy various hydrogen production, storage and delivery techniques as well as applications of hydrogen such as fuel cells for stationary, transportation (mobile) and portable applications. OPG maintains an active role in the demonstration of emerging technologies for a number of reasons: 1) advancing commercialization of emerging generation technologies, 2) 'hands-on' participation in the deployment of such technology in order to gather and apply market knowledge 3) Involvement in developing technology as a part of commitment to sustainable development. (author)

  2. The hydrogen refuelling plant in Madrid

    Energy Technology Data Exchange (ETDEWEB)

    Giron, E.; Saez, A.; Julia, A.

    2005-07-01

    Since the late days of spring 2003, a hydrogen refuelling station is operating in Madrid to provide fuel to a set of four FC-buses running in the frame of the European demonstration projects CUTE and CITYCELLS. This station is located at one of the EMT(1) bus depot premises. The station was designed and built for the EMT by the consortium 'esH2' composed by the industrial gases manufacturer Air Liquide Espana, the energy utility Gas Natural SDG and the oil company Repsol YPF. (Author)

  3. Solar powered hydrogen generating facility and hydrogen powered vehicle fleet. Final technical report, August 11, 1994--January 6, 1997

    Energy Technology Data Exchange (ETDEWEB)

    Provenzano, J.J.

    1997-04-01

    This final report describes activities carried out in support of a demonstration of a hydrogen powered vehicle fleet and construction of a solar powered hydrogen generation system. The hydrogen generation system was permitted for construction, constructed, and permitted for operation. It is not connected to the utility grid, either for electrolytic generation of hydrogen or for compression of the gas. Operation results from ideal and cloudy days are presented. The report also describes the achievement of licensing permits for their hydrogen powered trucks in California, safety assessments of the trucks, performance data, and information on emissions measurements which demonstrate performance better than the Ultra-Low Emission Vehicle levels.

  4. Portable Fuel Cell Battery Charger with Integrated Hydrogen Generator

    Energy Technology Data Exchange (ETDEWEB)

    Bossel, Ulf G. [CH-5452 Oberrohrdorf (Switzerland)

    1999-10-01

    A fully self-sufficient portable fuel cell battery charger has been designed, built, operated and is now prepared for commercialisation. The lightweight device is equipped with 24 circular polymer electrolyte cells of an innovative design. Each cell is a complete unit and can be tested prior to stacking. Hydrogen is admitted to the anode chamber from the centre of the cell. Air can reach the cathode by diffusion through a porous metal foam layer placed between cathode and separator plate. Soft seals surround the centre hole of the cells to separate hydrogen from air. Water vapour generated by the electrochemical conversion is released into the atmosphere via the porous metal foam on the cathode. All hydrogen fed to the dead-ended anode chamber is converted to electric power. The device is equipped with a chemical hydrogen generator. The fuel gas is formed by adding small amounts of water to a particular chemical compound which is contained in disposable cartridges. With one such cartridge enough hydrogen can be generated to operate CD-players, radios, recorders or portable computers for some hours, depending on the current drawn by the electronic device. The handy portable battery charger delivers about 10 W at 12 V DC. It is designed to be used in remote areas as autonomous power source for charging batteries used in radios, CD players, cellular telephones, radio transmitters, flash lights or model air planes. The power can also be used directly to provide light, sound or motion. Patents have been filed and partners are sought for commercialisation. (author) 4 figs.

  5. Sensitivity analyses on in-vessel hydrogen generation for KNGR

    International Nuclear Information System (INIS)

    Kim, See Darl; Park, S.Y.; Park, S.H.; Park, J.H.

    2001-03-01

    Sensitivity analyses for the in-vessel hydrogen generation, using the MELCOR program, are described in this report for the Korean Next Generation Reactor. The typical accident sequences of a station blackout and a large LOCA scenario are selected. A lower head failure model, a Zircaloy oxidation reaction model and a B 4 C reaction model are considered for the sensitivity parameters. As for the base case, 1273.15K for a failure temperature of the penetrations or the lower head, an Urbanic-Heidrich correlation for the Zircaloy oxidation reaction model and the B 4 C reaction model are used. Case 1 used 1650K as the failure temperature for the penetrations and Case 2 considered creep rupture instead of penetration failure. Case 3 used a MATPRO-EG and G correlation for the Zircaloy oxidation reaction model and Case 4 turned off the B 4 C reaction model. The results of the studies are summarized below : (1) When the penetration failure temperature is higher, or the creep rupture failure model is considered, the amount of hydrogen increases for two sequences. (2) When the MATPRO-EG and G correlation for a Zircaloy oxidation reaction is considered, the amount of hydrogen is less than the Urbanic-Heidrich correlation (Base case) for both scenarios. (3) When the B 4 C reaction model turns off, the amount of hydrogen decreases for two sequences

  6. Transportable Hydrogen Research Plant Based on Renewable Energy

    International Nuclear Information System (INIS)

    Mikel Fernandez; Carlos Madina; Asier Gil de Muro; Jose Angel Alzolab; Iker Marino; Javier Garcia-Tejedor; Juan Carlos Mugica; Inaki Azkkrate; Jose Angel Alzola

    2006-01-01

    Efficiency and cost are nowadays the most important barriers for the penetration of systems based on hydrogen and renewable energies. According to this background, TECNALIA Corporation has started in 2004 the HIDROTEC project: 'Hydrogen Technologies for Renewable Energy Applications'. The ultimate aim of this project is the implementation of a multipurpose demonstration and research plant in order to explore diverse options for sustainable energetic solutions based on hydrogen. The plant is conceived as an independent system that can be easily transported and assembled. Research and demonstration activities can thus be carried out at very different locations, including commercial renewable facilities. Modularity and scalability have also been taken into account for an optimised exploitation. (authors)

  7. WTP Waste Feed Qualification: Hydrogen Generation Rate Measurement Apparatus Testing Report

    Energy Technology Data Exchange (ETDEWEB)

    Stone, M. E. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Newell, J. D. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Smith, T. E. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Pareizs, J. M. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2016-06-01

    The generation rate of hydrogen gas in the Hanford tank waste will be measured during the qualification of the staged tank waste for processing in the Hanford Tank Waste Treatment and Immobilization Plant. Based on a review of past practices in measurement of the hydrogen generation, an apparatus to perform this measurement has been designed and tested for use during waste feed qualification. The hydrogen generation rate measurement apparatus (HGRMA) described in this document utilized a 100 milliliter sample in a continuously-purged, continuously-stirred vessel, with measurement of hydrogen concentration in the vent gas. The vessel and lid had a combined 220 milliliters of headspace. The vent gas system included a small condenser to prevent excessive evaporative losses from the sample during the test, as well as a demister and filter to prevent particle migration from the sample to the gas chromatography system. The gas chromatograph was an on line automated instrument with a large-volume sample-injection system to allow measurement of very low hydrogen concentrations. This instrument automatically sampled the vent gas from the hydrogen generation rate measurement apparatus every five minutes and performed data regression in real time. The fabrication of the hydrogen generation rate measurement apparatus was in accordance with twenty three (23) design requirements documented in the conceptual design package, as well as seven (7) required developmental activities documented in the task plan associated with this work scope. The HGRMA was initially tested for proof of concept with physical simulants, and a remote demonstration of the system was performed in the Savannah River National Laboratory Shielded Cells Mockup Facility. Final verification testing was performed using non-radioactive simulants of the Hanford tank waste. Three different simulants were tested to bound the expected rheological properties expected during waste feed qualification testing. These

  8. Arizona Public Service - Alternative Fuel (Hydrogen) Pilot Plant Design Report

    Energy Technology Data Exchange (ETDEWEB)

    James E. Francfort

    2003-12-01

    Hydrogen has promise to be the fuel of the future. Its use as a chemical reagent and as a rocket propellant has grown to over eight million metric tons per year in the United States. Although use of hydrogen is abundant, it has not been used extensively as a transportation fuel. To assess the viability of hydrogen as a transportation fuel and the viability of producing hydrogen using off-peak electric energy, Pinnacle West Capital Corporation (PNW) and its electric utility subsidiary, Arizona Public Service (APS) designed, constructed, and operates a hydrogen and compressed natural gas fueling station—the APS Alternative Fuel Pilot Plant. This report summarizes the design of the APS Alternative Fuel Pilot Plant and presents lessons learned from its design and construction. Electric Transportation Applications prepared this report under contract to the U.S. Department of Energy’s Advanced Vehicle Testing Activity. The Idaho National Engineering and Environmental Laboratory manages these activities for the Advanced Vehicle Testing Activity.

  9. High Efficiency Generation of Hydrogen Fuels Using Solar Thermochemical Splitting of Water

    Energy Technology Data Exchange (ETDEWEB)

    Heske, Clemens; Moujaes, Samir; Weimer, Alan; Wong, Bunsen; Siegal, Nathan; McFarland, Eric; Miller, Eric; Lewis, Michele; Bingham, Carl; Roth, Kurth; Sabacky, Bruce; Steinfeld, Aldo

    2011-09-29

    The objective of this work is to identify economically feasible concepts for the production of hydrogen from water using solar energy. The ultimate project objective was to select one or more competitive concepts for pilot-scale demonstration using concentrated solar energy. Results of pilot scale plant performance would be used as foundation for seeking public and private resources for full-scale plant development and testing. Economical success in this venture would afford the public with a renewable and limitless source of energy carrier for use in electric power load-leveling and as a carbon-free transportation fuel. The Solar Hydrogen Generation Research (SHGR) project embraces technologies relevant to hydrogen research under the Office of Hydrogen Fuel Cells and Infrastructure Technology (HFCIT) as well as concentrated solar power under the Office of Solar Energy Technologies (SET). Although the photoelectrochemical work is aligned with HFCIT, some of the technologies in this effort are also consistent with the skills and technologies found in concentrated solar power and photovoltaic technology under the Office of Solar Energy Technologies (SET). Hydrogen production by thermo-chemical water-splitting is a chemical process that accomplishes the decomposition of water into hydrogen and oxygen using only heat or a combination of heat and electrolysis instead of pure electrolysis and meets the goals for hydrogen production using only water and renewable solar energy as feed-stocks. Photoelectrochemical hydrogen production also meets these goals by implementing photo-electrolysis at the surface of a semiconductor in contact with an electrolyte with bias provided by a photovoltaic source. Here, water splitting is a photo-electrolytic process in which hydrogen is produced using only solar photons and water as feed-stocks. The thermochemical hydrogen task engendered formal collaborations among two universities, three national laboratories and two private sector

  10. Hydrogen, a bridge between mobility and distributed generation. Some consideration towards the hydrogen economy

    International Nuclear Information System (INIS)

    Valentino Romeri

    2006-01-01

    In this paper were analysed the most recent energy initiatives started by some national and international institution, with particular focus on hydrogen and fuel cell. It were also overviewed the national road-maps towards the hydrogen economy. In 2004, based on the most authoritative available data regarding future FCVs penetration it was observed that, if vehicle power-generation system fuel cell based becomes more sophisticated, the role of the vehicles within the power grid might change. Fuel Cell Vehicle (FVC) could become a new power-generation source, supplying electricity to home and to the grid. Also, it was defined the dimension of this new kind of power generation source in different areas and it was compared with the related power grid installed generation capacity and it was found that this new source could be a multiple of the foreseeable installed capacity in year 2030. In the present work it was revised the analysis with the most recent scenarios and it was found that the results do not change significantly. Unfortunately this kind of analysis is still not considered in the energy debate or in the road-maps towards the hydrogen economy. (author)

  11. Steam generators for nuclear power plants

    International Nuclear Information System (INIS)

    Tillequin, Jean

    1975-01-01

    The role and the general characteristics of steam generators in nuclear power plants are indicated, and particular types are described according to the coolant nature (carbon dioxide, helium, light water, heavy water, sodium) [fr

  12. Refurbishment of hydropower generation plants

    International Nuclear Information System (INIS)

    Kofler, W.

    2001-01-01

    This article presents the factors taken into consideration and the methods used for the management of refurbishment work in the hydropower installations of the TUWAG - a Tyrolean hydropower company in Austria. The technical and financial advantages to be gained from refurbishment are discussed and the requirements placed on the structuring of refurbishment projects are described. Various factors such as plant operation and maintenance, increased returns through better efficiency and cost reduction through lower wear and tear and reduced risk of failure are discussed. Annexes to the article cover monitoring and measurement techniques, the simulation of mechanical and hydraulic conditions, profitability calculations and turbine management

  13. Removal of hydrogen fluoride from uranium plant emissions

    International Nuclear Information System (INIS)

    Ramani, M.P.S.

    1997-01-01

    Uranium production technology involves the use of hydrogen fluoride at various stages. It is used in the production of uranium tetrafluoride as well as for the production of fluorine for the conversion of tetrafluoride to hexafluoride in isotopic enrichment plants. The sources of HF pollution in the industry, besides accidental spillages and leakages, are the final off-gases from the UF 4 production process or from the hydrogen reduction of hexafluoride (where such process is adopted), venting of tanks and reactors containing HF, safety pressure rupture discs as well as dust collection and ventilation systems

  14. Hydrogen/oxygen injection stopping method for nuclear power plant and emergent hydrogen/oxygen injection device

    International Nuclear Information System (INIS)

    Ishida, Ryoichi; Ota, Masamoto; Takagi, Jun-ichi; Hirose, Yuki

    1998-01-01

    The present invention provides a device for suppressing increase of electroconductivity of reactor water during operation of a BWR type reactor, upon occurrence of reactor scram of the plant or upon stopping of hydrogen/oxygen injection due to emergent stoppage of an injection device so as not to deteriorate the integrity of a gas waste processing system upon occurrence of scram. Namely, when injection of hydrogen/oxygen is stopped during plant operation, the injection amount of hydrogen is reduced gradually. Subsequently, injection of hydrogen is stopped. With such procedures, the increase of electroconductivity of reactor water can be suppressed upon stoppage of hydrogen injection. When injection of hydrogen/oxygen is stopped upon shut down of the plant, the amount of hydrogen injection is changed depending on the change of the feedwater flow rate, and then the plant is shut down while keeping hydrogen concentration of feedwater to a predetermined value. With such procedures, increase of the reactor water electroconductivity can be suppressed upon stoppage of hydrogen injection. Upon emergent stoppage of the hydrogen/oxygen injection device, an emergent hydrogen/oxygen injection device is actuated to continue the injection of hydrogen/oxygen. With such procedures, elevation of reactor water electroconductivity can be suppressed. (I.S.)

  15. Molecular metal-Oxo catalysts for generating hydrogen from water

    Science.gov (United States)

    Long, Jeffrey R; Chang, Christopher J; Karunadasa, Hemamala I

    2015-02-24

    A composition of matter suitable for the generation of hydrogen from water is described, the positively charged cation of the composition having the general formula [(PY5W.sub.2)MO].sup.2+, wherein PY5W.sub.2 is (NC.sub.5XYZ)(NC.sub.5H.sub.4).sub.4C.sub.2W.sub.2, M is a transition metal, and W, X, Y, and Z can be H, R, a halide, CF.sub.3, or SiR.sub.3, where R can be an alkyl or aryl group. The two accompanying counter anions, in one embodiment, can be selected from the following Cl.sup.-, I.sup.-, PF.sub.6.sup.-, and CF.sub.3SO.sub.3.sup.-. In embodiments of the invention, water, such as tap water containing electrolyte or straight sea water can be subject to an electric potential of between 1.0 V and 1.4 V relative to the standard hydrogen electrode, which at pH 7 corresponds to an overpotential of 0.6 to 1.0 V, with the result being, among other things, the generation of hydrogen with an optimal turnover frequency of ca. 1.5 million mol H.sub.2/mol catalyst per h.

  16. Atomistic Modelling of Materials for Clean Energy Applications : hydrogen generation, hydrogen storage, and Li-ion battery

    OpenAIRE

    Qian, Zhao

    2013-01-01

    In this thesis, a number of clean-energy materials for hydrogen generation, hydrogen storage, and Li-ion battery energy storage applications have been investigated through state-of-the-art density functional theory. As an alternative fuel, hydrogen has been regarded as one of the promising clean energies with the advantage of abundance (generated through water splitting) and pollution-free emission if used in fuel cell systems. However, some key problems such as finding efficient ways to prod...

  17. Sum Frequency Generation Studies of Hydrogenation Reactions on Platinum Nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Krier, James M. [Univ. of California, Berkeley, CA (United States)

    2013-08-31

    Sum Frequency Generation (SFG) vibrational spectroscopy is used to characterize intermediate species of hydrogenation reactions on the surface of platinum nanoparticle catalysts. In contrast to other spectroscopy techniques which operate in ultra-high vacuum or probe surface species after reaction, SFG collects information under normal conditions as the reaction is taking place. Several systems have been studied previously using SFG on single crystals, notably alkene hydrogenation on Pt(111). In this thesis, many aspects of SFG experiments on colloidal nanoparticles are explored for the first time. To address spectral interference by the capping agent (PVP), three procedures are proposed: UV cleaning, H2 induced disordering and calcination (core-shell nanoparticles). UV cleaning and calcination physically destroy organic capping while disordering reduces SFG signal through a reversible structural change by PVP.

  18. Nitric-glycolic flowsheet testing for maximum hydrogen generation rate

    Energy Technology Data Exchange (ETDEWEB)

    Martino, C. J. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Newell, J. D. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Williams, M. S. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2016-03-01

    The Defense Waste Processing Facility (DWPF) at the Savannah River Site is developing for implementation a flowsheet with a new reductant to replace formic acid. Glycolic acid has been tested over the past several years and found to effectively replace the function of formic acid in the DWPF chemical process. The nitric-glycolic flowsheet reduces mercury, significantly lowers the chemical generation of hydrogen and ammonia, allows purge reduction in the Sludge Receipt and Adjustment Tank (SRAT), stabilizes the pH and chemistry in the SRAT and the Slurry Mix Evaporator (SME), allows for effective adjustment of the SRAT/SME rheology, and is favorable with respect to melter flammability. The objective of this work was to perform DWPF Chemical Process Cell (CPC) testing at conditions that would bound the catalytic hydrogen production for the nitric-glycolic flowsheet.

  19. Implementation of hydrogen mitigation techniques during severe accidents in nuclear power plants

    International Nuclear Information System (INIS)

    1996-01-01

    concentration and under special geometric conditions, an accelerated flame or even a local detonation may occur which would produce higher dynamic loads than a deflagration and a more serious threat to equipment and structures. Should it occur in spite of its low probability, a global detonation, following prolonged and extensive accumulation of hydrogen in the containment atmosphere, would be a major threat to the containment integrity. The goal of hydrogen mitigation techniques is to prevent loads, resulting from hydrogen combustion, which could threaten containment integrity. The risk of containment failure depends on the overall hydrogen concentration which is dependent on the amount of hydrogen released and the containment volume. A possible containment failure also depends on the containment structure and design which is very important in the resistance of the containment to a global combustion. Geometrical sub-compartmentalization is also very important, because significant amounts of hydrogen could accumulate in compartments to create high local concentrations of hydrogen that could be well within the detonability limits. Once accident management measures aimed at preventing severe accidents from occurring have failed and hydrogen is being generated and released to the containment atmosphere in large amounts, the first step is to reduce the possibility of hydrogen accumulating to flammable concentrations. Where flammable concentrations cannot be precluded, the next step is to minimize the volume of gas at flammable concentrations and the third and last step is to prevent further increasing hydrogen levels from the flammable to detonable mixture concentrations. The purpose of this paper is to present a snapshot, from a technical viewpoint, of the current situation regarding the implementation of hydrogen mitigation techniques for severe accident conditions in nuclear power plants. Broader aspects related to overall accident management policies are not considered here

  20. CO2-based hydrogen storage - Hydrogen generation from formaldehyde/water

    Science.gov (United States)

    Trincado, Monica; Grützmacher, Hansjörg; Prechtl, Martin H. G.

    2018-04-01

    Formaldehyde (CH2O) is the simplest and most significant industrially produced aldehyde. The global demand is about 30 megatons annually. Industrially it is produced by oxidation of methanol under energy intensive conditions. More recently, new fields of application for the use of formaldehyde and its derivatives as, i.e. cross-linker for resins or disinfectant, have been suggested. Dialkoxymethane has been envisioned as a combustion fuel for conventional engines or aqueous formaldehyde and paraformaldehyde may act as a liquid organic hydrogen carrier molecule (LOHC) for hydrogen generation to be used for hydrogen fuel cells. For the realization of these processes, it requires less energy-intensive technologies for the synthesis of formaldehyde. This overview summarizes the recent developments in low-temperature reductive synthesis of formaldehyde and its derivatives and low-temperature formaldehyde reforming. These aspects are important for the future demands on modern societies' energy management, in the form of a methanol and hydrogen economy, and the required formaldehyde feedstock for the manufacture of many formaldehyde-based daily products.

  1. A comparative economic assessment of hydrogen production from large central versus smaller distributed plant in a carbon constrained world

    International Nuclear Information System (INIS)

    Nguyen, Y.V.; Ngo, Y.A.; Tinkler, M.J.; Cowan, N.

    2003-01-01

    This paper compares the economics of producing hydrogen at large central plants versus smaller distributed plants at user sites. The economics of two types of central plant, each at 100 million standard cubic feet per day of hydrogen, based on electrolysis and natural gas steam reforming technologies, will be discussed. The additional cost of controlling CO 2 emissions from the natural gas steam reforming plant will be included in the analysis in order to satisfy the need to live in a future carbon constrained world. The cost of delivery of hydrogen from the large central plant to the user sites in a large metropolitan area will be highlighted, and the delivered cost will be compared to the cost from on-site distributed generation plants. Five types of distributed generation plants, based on proton exchange membrane, alkaline electrolysis and advanced steam reforming, will be analysed and discussed. Two criteria were used to rank various hydrogen production options, the cost of production and the price of hydrogen to achieve an acceptable return of investment. (author)

  2. Next Generation Nuclear Plant Materials Selection and Qualification Program Plan

    Energy Technology Data Exchange (ETDEWEB)

    R. Doug Hamelin; G. O. Hayner

    2004-11-01

    The U.S. Department of Energy (DOE) has selected the Very High Temperature Reactor (VHTR) design for the Next Generation Nuclear Plant (NGNP) Project. The NGNP will demonstrate the use of nuclear power for electricity and hydrogen production without greenhouse gas emissions. The reactor design is a graphite-moderated, helium-cooled, prismatic or pebble bed thermal neutron spectrum reactor with an average reactor outlet temperature of at least 1000 C. The NGNP will use very high burn up, lowenriched uranium, TRISO-Coated fuel in a once-through fuel cycle. The design service life of the NGNP is 60 years.

  3. 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)

  4. A Renewably Powered Hydrogen Generation and Fueling Station Community Project

    Science.gov (United States)

    Lyons, Valerie J.; Sekura, Linda S.; Prokopius, Paul; Theirl, Susan

    2009-01-01

    The proposed project goal is to encourage the use of renewable energy and clean fuel technologies for transportation and other applications while generating economic development. This can be done by creating an incubator for collaborators, and creating a manufacturing hub for the energy economy of the future by training both white- and blue-collar workers for the new energy economy. Hydrogen electrolyzer fueling stations could be mass-produced, shipped and installed in collaboration with renewable energy power stations, or installed connected to the grid with renewable power added later.

  5. Reforming water to generate hydrogen using mechanical alloy

    International Nuclear Information System (INIS)

    Pena F, D. L.

    2016-01-01

    The objective of this research was to generate a hydrogen production system by means of mechanical milling, in which 0.1 g of magnesium were weighed using a volume of 300 μL for each water solvent (H_2O) and methanol (CH_3OH) in a container to start mechanical milling for 2, 4 and 6 h. Once the mechanical milling was finished, the hydrogen that was produced every two hours was measured to determine the appropriate milling time in the production, also in each period of time samples of the powders produced during the milling of Mg were taken, in this process we used characterization techniques such as: X-ray diffraction at an angle of 2θi 5 and 2θf 90 degrees and scanning electron microscopy, taking micrographs of 100, 500, 1000 and 5000 magnifications. According to the mechanical milling results hydrogen was obtained when using water, as well as with methanol. In the techniques of X-ray diffraction characterization different results were obtained before and after the milling, since by the diffractogram s is possible to observe how the magnesium to be put in the mechanical milling along with the water and methanol was diminishing to be transformed into hydroxide and magnesium oxide, as well as in the micrographs taken with scanning electron microscopy the change in the magnesium morphology to hydroxide and magnesium oxide is observed. (Author)

  6. Compact PEM fuel cell system combined with all-in-one hydrogen generator using chemical hydride as a hydrogen source

    International Nuclear Information System (INIS)

    Kim, Jincheol; Kim, Taegyu

    2015-01-01

    Highlights: • Compact fuel cell system was developed for a portable power generator. • Novel concept using an all-in-one reactor for hydrogen generation was proposed. • Catalytic reactor, hydrogen chamber and separator were combined in a volume. • The system can be used to drive fuel cell-powered unmanned autonomous systems. - Abstract: Compact fuel cell system was developed for a portable power generator. The power generator features a polymer electrolyte membrane fuel cell (PEMFC) using a chemical hydride as a hydrogen source. The hydrogen generator extracted hydrogen using a catalytic hydrolysis from a sodium borohydride alkaline solution. A novel concept using an all-in-one reactor was proposed in which a catalyst, hydrogen chamber and byproduct separator were combined in a volume. In addition, the reactor as well as a pump, cooling fans, valves and controller was integrated in a single module. A 100 W PEMFC stack was connected with the hydrogen generator and was evaluated at various load conditions. It was verified that the stable hydrogen supply was achieved and the developed system can be used to drive fuel cell-powered unmanned autonomous systems.

  7. Second generation biofuels, an accelerator of the transition toward an economy driven by energy drawn from hydrogen

    International Nuclear Information System (INIS)

    Delabroy, O.

    2013-01-01

    The growth of the bio economy, especially in transportation, involves developing a bio-fuel industry. First generation bio-fuels were produced from plant sugars like starch or from plant oils. Second generation bio fuels use as raw materials the whole plant and especially agricultural and forestry wastes which extend the resource considerably and limit the competition between food use and fuel use. Second generation bio-fuels can be made with not only biological methods but also biomass-to-liquid processes borrowed from thermochemistry. Players in this field, including 'Air Liquide' company, are drawing up a technical and economic road-map for competitiveness in this emerging branch of industry. Since the thermochemical approach for gasifying a biomass also yields large quantities of hydrogen, the industrialization of this branch and concomitant production of bio-hydrogen at competitive prices provide leverage for accelerating the transition toward using H 2 for transportation

  8. Very High Efficiency Reactor (VHER) Concepts for Electrical Power Generation and Hydrogen Production

    International Nuclear Information System (INIS)

    PARMA JR, EDWARD J.; PICKARD, PAUL S.; SUO-ANTTILA, AHTI JORMA

    2003-01-01

    The goal of the Very High Efficiency Reactor study was to develop and analyze concepts for the next generation of nuclear power reactors. The next generation power reactor should be cost effective compared to current power generation plant, passively safe, and proliferation-resistant. High-temperature reactor systems allow higher electrical generating efficiencies and high-temperature process heat applications, such as thermo-chemical hydrogen production. The study focused on three concepts; one using molten salt coolant with a prismatic fuel-element geometry, the other two using high-pressure helium coolant with a prismatic fuel-element geometry and a fuel-pebble element design. Peak operating temperatures, passive-safety, decay heat removal, criticality, burnup, reactivity coefficients, and material issues were analyzed to determine the technical feasibility of each concept

  9. Power generation by nuclear power plants

    International Nuclear Information System (INIS)

    Bacher, P.

    2004-01-01

    Nuclear power plays an important role in the world, European (33%) and French (75%) power generation. This article aims at presenting in a synthetic way the main reactor types with their respective advantages with respect to the objectives foreseen (power generation, resources valorization, waste management). It makes a fast review of 50 years of nuclear development, thanks to which the nuclear industry has become one of the safest and less environmentally harmful industry which allows to produce low cost electricity: 1 - simplified description of a nuclear power generation plant: nuclear reactor, heat transfer system, power generation system, interface with the power distribution grid; 2 - first historical developments of nuclear power; 3 - industrial development and experience feedback (1965-1995): water reactors (PWR, BWR, Candu), RBMK, fast neutron reactors, high temperature demonstration reactors, costs of industrial reactors; 4 - service life of nuclear power plants and replacement: technical, regulatory and economical lifetime, problems linked with the replacement; 5 - conclusion. (J.S.)

  10. Major plant retrofits at Monticello nuclear generating plant

    International Nuclear Information System (INIS)

    Larsen, D.E.; Hogg, C.B.

    1986-01-01

    For the past several years, Northern States Power (NSP) has been making major plant retrofits to Monticello Nuclear generating Station in order to improve plant availability and upgrade the plant components for the potential extension of the operating license (life extension). This paper discusses in detail three major retrofits that have been completed or in the process of completion; recirculation loop piping replacement, reactor pressure vessel (RPV) water level-instrumentation modification, core spray piping replacement, the authors will address the scope of work, design and installation concerns, and life extension considerations during the design and procurement process for these three projects

  11. The next generation of CANDU technologies: profiling the potential for hydrogen fuel

    International Nuclear Information System (INIS)

    Hopwood, J.M.

    2001-01-01

    This report discusses the Next-generation CANDU Power Reactor technologies currently under development at AECL. The innovations introduced into proven CANDU technologies include a compact reactor core design, which reduces the size by a factor of one third for the same power output; improved thermal efficiency through higher-pressure steam turbines; reduced use of heavy water (one quarter of the heavy water required for existing plants), thus reducing the cost and eliminating many material handling concerns; use of slightly enriched uranium to extend fuel life to three times that of existing natural uranium fuel and additions to CANDU's inherent passive safety. With these advanced features, the capital cost of constructing the plant can be reduced by up to 40 per cent compared to existing designs. The clean, affordable CANDU-generated electricity can be used to produce hydrogen for fuel cells for the transportation sector, thereby reducing emissions from the transportation sector

  12. Identification of intrinsic catalytic activity for electrochemical reduction of water molecules to generate hydrogen

    KAUST Repository

    Shinagawa, Tatsuya; Takanabe, Kazuhiro

    2015-01-01

    Insufficient hydronium ion activities at near-neutral pH and under unbuffered conditions induce diffusion-limited currents for hydrogen evolution, followed by a reaction with water molecules to generate hydrogen at elevated potentials. The observed

  13. First-Generation Transgenic Plants and Statistics

    NARCIS (Netherlands)

    Nap, Jan-Peter; Keizer, Paul; Jansen, Ritsert

    1993-01-01

    The statistical analyses of populations of first-generation transgenic plants are commonly based on mean and variance and generally require a test of normality. Since in many cases the assumptions of normality are not met, analyses can result in erroneous conclusions. Transformation of data to

  14. Development of a high-efficiency hydrogen generator for fuel cells for distributed power generation

    Energy Technology Data Exchange (ETDEWEB)

    Duraiswamy, K.; Chellappa, Anand [Intelligent Energy, 2955 Redondo Ave., Long Beach, CA 90806 (United States); Smith, Gregory; Liu, Yi; Li, Mingheng [Department of Chemical and Materials Engineering, California State Polytechnic University, Pomona, CA 91768 (United States)

    2010-09-15

    A collaborative effort between Intelligent Energy and Cal Poly Pomona has developed an adsorption enhanced reformer (AER) for hydrogen generation for use in conjunction with fuel cells in small sizes. The AER operates at a lower temperature (about 500 C) and has a higher hydrogen yield and purity than those in the conventional steam reforming. It employs ceria supported rhodium as the catalyst and potassium-promoted hydrotalcites to remove carbon dioxide from the products. A novel pulsing feed concept is developed for the AER operation to allow a deeper conversion of the feedstock to hydrogen. Continuous production of near fuel-cell grade hydrogen is demonstrated in the AER with four packed beds running alternately. In the best case of methane reforming, the overall conversion to hydrogen is 92% while the carbon dioxide and carbon monoxide concentrations in the production stream are on the ppm level. The ratio of carbon dioxide in the regeneration exhaust to the one in the product stream is on the order of 10{sup 3}. (author)

  15. A lignite-geothermal hybrid power and hydrogen production plant for green cities and sustainable buildings

    Energy Technology Data Exchange (ETDEWEB)

    Kilkis, B. [Baskent University, Ankara (Turkey). Dept. of Mechanical Engineering

    2011-02-15

    Turkey is rich in both geothermal energy and lignite reserves, which in many cases, are co-located. This condition makes it feasible to utilize both lignite and geothermal energy in a hybrid form for combined power heat, and cold generation, which may lead to optimally energy and exergy efficient, environmentally benign, and economically sound applications. This paper presents a novel concept of hybrid lignite-geothermal plant for a district energy system and hydrogen production facility in Aydin with special emphasis on high performance, green buildings and green districts. In this concept, lignite is first introduced to a partially fluidized-bed gasifier and then to a fluidized-bed gas cleaning unit, which produces synthetic gas and finally hydrogen. The by-products, namely char and ash are used in a fluidized-bed combustor to produce power. Waste heat from all these steps are utilized in a district heating system along with heat received from geothermal production wells after power is generated there. H{sub 2}S gas obtained from the separator system is coupled with hydrogen production process at the lignite plant. Absorption cooling systems and thermal storage tanks complement the hybrid system for the tri-generation district energy system. On the demand side, the new, green OSTIM OSB administration building in Ankara is exemplified for greener, low-exergy buildings that will compound the environmental benefits.

  16. Surface- and interface-engineered heterostructures for solar hydrogen generation

    Science.gov (United States)

    Chen, Xiangyan; Li, Yanrui; Shen, Shaohua

    2018-04-01

    Photoelectrochemical (PEC) water splitting based on semiconductor photoelectrodes provides a promising platform for reducing environmental pollution and solving the energy crisis by developing clean, sustainable and environmentally friendly hydrogen energy. In this context, metal oxides with their advantages including low cost, good chemical stability and environmental friendliness, have attracted extensive attention among the investigated candidates. However, the large bandgap, poor charge transfer ability and high charge recombination rate limit the PEC performance of metal oxides as photoelectrodes. To solve this limitation, many approaches toward enhanced PEC water splitting performance, which focus on surface and interface engineering, have been presented. In this topical review, we concentrate on the heterostructure design of some typical metal oxides with narrow bandgaps (e.g. Fe2O3, WO3, BiVO4 and Cu2O) as photoelectrodes. An overview of the surface- and interface-engineered heterostructures, including semiconductor heterojunctions, surface protection, surface passivation and cocatalyst decoration, will be given to introduce the recent advances in metal oxide heterostructures for PEC water splitting. This article aims to provide fundamental references and principles for designing metal oxide heterostructures with high activity and stability as photoelectrodes for PEC solar hydrogen generation.

  17. Modeling of Syngas Reactions and Hydrogen Generation Over Sulfides

    Energy Technology Data Exchange (ETDEWEB)

    Kamil Klier; Jeffery A. Spirko; Michael L. Neiman

    2002-09-17

    The objective of the research is to analyze pathways of reactions of hydrogen with oxides of carbon over sulfides, and to predict which characteristics of the sulfide catalyst (nature of metal, defect structure) give rise to the lowest barriers toward oxygenated hydrocarbon product. Reversal of these pathways entails the generation of hydrogen, which is also proposed for study. In this first year of study, adsorption reactions of H atoms and H{sub 2} molecules with MoS{sub 2}, both in molecular and solid form, have been modeled using high-level density functional theory. The geometries and strengths of the adsorption sites are described and the methods used in the study are described. An exposed MO{sup IV} species modeled as a bent MoS{sub 2} molecule is capable of homopolar dissociative chemisorption of H{sub 2} into a dihydride S{sub 2}MoH{sub 2}. Among the periodic edge structures of hexagonal MoS{sub 2}, the (1{bar 2}11) edge is most stable but still capable of dissociating H{sub 2}, while the basal plane (0001) is not. A challenging task of theoretically accounting for weak bonding of MoS{sub 2} sheets across the Van der Waals gap has been addressed, resulting in a weak attraction of 0.028 eV/MoS{sub 2} unit, compared to the experimental value of 0.013 eV/MoS{sub 2} unit.

  18. Generation of hydrogen free radicals from water for fuels by electric field induction

    International Nuclear Information System (INIS)

    Nong, Guangzai; Chen, Yiyi; Li, Ming; Zhou, Zongwen

    2015-01-01

    Highlights: • Hydrogen free radicals are generated from water splitting. • Hydrogen fuel is generated from water by electric field induction. • Hydrocarbon fuel is generated from CO_2 and water by electric field induction. - Abstract: Water is the most abundant resource for generating hydrogen fuel. In addition to dissociating H"+ and "−OH ions, certain water molecules dissociate to radicals under an electric field are considered. Therefore, an electric field inducing reactor is constructed and operated to generate hydrogen free radicals in this paper. Hydrogen free radicals begin to be generated under a 1.0 V electric field, and increasing the voltage and temperature increases the number of hydrogen free radicals. The production rate of hydrogen free radicals is 0.245 mmol/(L h) at 5.0 V and room temperature. The generated hydrogen free radicals are converted to polymer fuel and hydrogen fuel at production rates of 0.0093 mmol/(L h) and 0.0038 mmol/(L h) respectively, under 5.0 V and 0.25 mA. The results provide a way to generate hydrogen free radicals, which might be used to generate hydrocarbon fuel in industrial manufacture.

  19. Investigation and analysis of hydrogen ignition and explosion events in foreign nuclear power plants

    Energy Technology Data Exchange (ETDEWEB)

    Okuda, Yasunori [Institute of Nuclear Safety System, Inc., Mihama, Fukui (Japan)

    2002-09-01

    Reports about hydrogen ignition and explosion events in foreign nuclear power plants from 1980 to 2001 were investigated, and 31 events were identified. Analysis showed that they were categorized in (1) outer leakage ignition events and (2) inner accumulation ignition events. The dominant event for PWR (pressurized water reactor) was outer leakage ignition in the main generator, and in BWR (boiling water reactor) it was inner accumulation ignition in the off-gas system. The outer leakage ignition was a result of work process failure with the ignition source, operator error, or main generator hydrogen leakage. The inner accumulation ignition events were caused by equipment failure or insufficient monitoring. With careful preventive measures, the factors leading to these events could be eliminated. (author)

  20. 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.

  1. Broad Spectrum Photoelectrochemical Diodes for Solar Hydrogen Generation

    Energy Technology Data Exchange (ETDEWEB)

    Grimes, Craig A.

    2014-11-26

    Under program auspices we have investigated material chemistries suitable for the solar generation of hydrogen by water photoelectrolysis. We have built upon, and extended, our knowledge base on the synthesis and application of TiO2 nanotube arrays, a material architecture that appears ideal for water photoelectrolysis. To date we have optimized, refined, and greatly extended synthesis techniques suitable for achieving highly ordered TiO2 nanotube arrays of given length, wall thickness, pore diameter, and tube-to-tube spacing for use in water photoelectrolysis. We have built upon this knowledge based to achieve visible light responsive, photocorrosion stable n-type and p-type ternary oxide nanotube arrays for use in photoelectrochemical diodes.

  2. Next-generation TCAP hydrogen isotope separation process

    International Nuclear Information System (INIS)

    Heung, L. K.; Sessions, H. T.; Poore, A. S.; Jacobs, W. D.; Williams, C. S.

    2008-01-01

    A thermal cycling absorption process (TCAP) for hydrogen isotope separation has been in operation at Savannah River Site since 1994. The process uses a hot/cold nitrogen system to cycle the temperature of the separation column. The hot/cold nitrogen system requires the use of large compressors, heat exchanges, valves and piping that is bulky and maintenance intensive. A new compact thermal cycling (CTC) design has recently been developed. This new design uses liquid nitrogen tubes and electric heaters to heat and cool the column directly so that the bulky hot/cold nitrogen system can be eliminated. This CTC design is simple and is easy to implement, and will be the next generation TCAP system at SRS. A twelve-meter column has been fabricated and installed in the laboratory to demonstrate its performance. The design of the system and its test results to date is discussed. (authors)

  3. Next Generation Nuclear Plant Research and Development Program Plan

    Energy Technology Data Exchange (ETDEWEB)

    P. E. MacDonald

    2005-01-01

    The U.S Department of Energy (DOE) is conducting research and development (R&D) on the Very High Temperature Reactor (VHTR) design concept for the Next Generation Nuclear Plant (NGNP) Project. The reactor design will be a graphite moderated, thermal neutron spectrum reactor that will produce electricity and hydrogen in a highly efficient manner. The NGNP reactor core could be either a prismatic graphite block type core or a pebble bed core. Use of a liquid salt coolant is also being evaluated. The NGNP will use very high-burnup, low-enriched uranium, TRISO-coated fuel, and have a projected plant design service life of 60 years. The VHTR concept is considered to be the nearest-term reactor design that has the capability to efficiently produce hydrogen. The plant size, reactor thermal power, and core configuration will ensure passive decay heat removal without fuel damage or radioactive material releases during accidents. The objectives of the NGNP Project are to: Demonstrate a full-scale prototype VHTR that is commercially licensed by the U.S. Nuclear Regulatory Commission Demonstrate safe and economical nuclearassisted production of hydrogen and electricity. The DOE laboratories, led by the INL, will perform R&D that will be critical to the success of the NGNP, primarily in the areas of: High temperature gas reactor fuels behavior High temperature materials qualification Design methods development and validation Hydrogen production technologies Energy conversion. The current R&D work is addressing fundamental issues that are relevant to a variety of possible NGNP designs. This document describes the NGNP R&D planned and currently underway in the first three topic areas listed above. The NGNP Advanced Gas Reactor (AGR) Fuel Development and Qualification Program is presented in Section 2, the NGNP Materials R&D Program Plan is presented in Section 3, and the NGNP Design Methods Development and Validation R&D Program is presented in Section 4. The DOE-funded hydrogen

  4. Next Generation Nuclear Plant Research and Development Program Plan

    Energy Technology Data Exchange (ETDEWEB)

    None

    2005-01-01

    The U.S Department of Energy (DOE) is conducting research and development (R&D) on the Very High Temperature Reactor (VHTR) design concept for the Next Generation Nuclear Plant (NGNP) Project. The reactor design will be a graphite moderated, thermal neutron spectrum reactor that will produce electricity and hydrogen in a highly efficient manner. The NGNP reactor core could be either a prismatic graphite block type core or a pebble bed core. Use of a liquid salt coolant is also being evaluated. The NGNP will use very high-burnup, low-enriched uranium, TRISO-coated fuel, and have a projected plant design service life of 60 years. The VHTR concept is considered to be the nearest-term reactor design that has the capability to efficiently produce hydrogen. The plant size, reactor thermal power, and core configuration will ensure passive decay heat removal without fuel damage or radioactive material releases during accidents. The objectives of the NGNP Project are to: (1) Demonstrate a full-scale prototype VHTR that is commercially licensed by the U.S. Nuclear Regulatory Commission (2) Demonstrate safe and economical nuclear-assisted production of hydrogen and electricity. The DOE laboratories, led by the INL, will perform R&D that will be critical to the success of the NGNP, primarily in the areas of: (1) High temperature gas reactor fuels behavior; (2) High temperature materials qualification; (3) Design methods development and validation; (4) Hydrogen production technologies; and (5) Energy conversion. The current R&D work is addressing fundamental issues that are relevant to a variety of possible NGNP designs. This document describes the NGNP R&D planned and currently underway in the first three topic areas listed above. The NGNP Advanced Gas Reactor (AGR) Fuel Development and Qualification Program is presented in Section 2, the NGNP Materials R&D Program Plan is presented in Section 3, and the NGNP Design Methods Development and Validation R&D Program is presented

  5. Nitrogen-Doped Graphene for Photocatalytic Hydrogen Generation.

    Science.gov (United States)

    Chang, Dong Wook; Baek, Jong-Beom

    2016-04-20

    Photocatalytic hydrogen (H2 ) generation in a water splitting process has recently attracted tremendous interest because it allows the direct conversion of clean and unlimited solar energy into the ideal energy resource of H2 . For efficient photocatalytic H2 generation, the role of the photocatalyst is critical. With increasing demand for more efficient, sustainable, and cost-effective photocatalysts, various types of semiconductor photocatalysts have been intensively developed. In particular, on the basis of its superior catalytic and tunable electronic properties, nitrogen-doped graphene is a potential candidate for a high-performance photocatalyst. Nitrogen-doped graphene also offers additional advantages originating from its unique two-dimensional sp(2) -hybridized carbon network including a large specific surface area and exceptional charge transport properties. It has been reported that nitrogen-doped graphene can play diverse but positive functions including photo-induced charge acceptor/meditator, light absorber from UV to visible light, n-type semiconductor, and giant molecular photocatalyst. Herein, we summarize the recent progress and general aspects of nitrogen-doped graphene as a photocatalyst for photocatalytic H2 generation. In addition, challenges and future perspectives in this field are also discussed. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. 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

  7. Next Generation Nuclear Plant Materials Research and Development Program Plan

    International Nuclear Information System (INIS)

    G.O. Hayner; R.L. Bratton; R.N. Wright

    2005-01-01

    The U.S Department of Energy (DOE) has selected the Very High Temperature Reactor (VHTR) design for the Next Generation Nuclear Plant (NGNP) Project. The NGNP will demonstrate the use of nuclear power for electricity and hydrogen production without greenhouse gas emissions. The reactor design will be a graphite moderated, helium-cooled, prismatic or pebble-bed, thermal neutron spectrum reactor that will produce electricity and hydrogen in a state-of-the-art thermodynamically efficient manner. The NGNP will use very high burn-up, low-enriched uranium, TRISO-coated fuel and have a projected plant design service life of 60 years. The VHTR concept is considered to be the nearest-term reactor design that has the capability to efficiently produce hydrogen. The plant size, reactor thermal power, and core configuration will ensure passive decay heat removal without fuel damage or radioactive material releases during accidents. The NGNP Project is envisioned to demonstrate the following: (1) A full-scale prototype VHTR by about 2021; (2) High-temperature Brayton Cycle electric power production at full scale with a focus on economic performance; (3) Nuclear-assisted production of hydrogen (with about 10% of the heat) with a focus on economic performance; and (4) By test, the exceptional safety capabilities of the advanced gas-cooled reactors. Further, the NGNP program will: (1) Obtain a Nuclear Regulatory Commission (NRC) License to construct and operate the NGNP, this process will provide a basis for future performance based, risk-informed licensing; and (2) Support the development, testing, and prototyping of hydrogen infrastructures. The NGNP Materials Research and Development (R and D) Program is responsible for performing R and D on likely NGNP materials in support of the NGNP design, licensing, and construction activities. The NGNP Materials R and D Program includes the following elements: (1) Developing a specific approach, program plan and other project management

  8. Next Generation Nuclear Plant Materials Research and Development Program Plan

    Energy Technology Data Exchange (ETDEWEB)

    G.O. Hayner; R.L. Bratton; R.N. Wright

    2005-09-01

    The U.S Department of Energy (DOE) has selected the Very High Temperature Reactor (VHTR) design for the Next Generation Nuclear Plant (NGNP) Project. The NGNP will demonstrate the use of nuclear power for electricity and hydrogen production without greenhouse gas emissions. The reactor design will be a graphite moderated, helium-cooled, prismatic or pebble-bed, thermal neutron spectrum reactor that will produce electricity and hydrogen in a state-of-the-art thermodynamically efficient manner. The NGNP will use very high burn-up, low-enriched uranium, TRISO-coated fuel and have a projected plant design service life of 60 years. The VHTR concept is considered to be the nearest-term reactor design that has the capability to efficiently produce hydrogen. The plant size, reactor thermal power, and core configuration will ensure passive decay heat removal without fuel damage or radioactive material releases during accidents. The NGNP Project is envisioned to demonstrate the following: (1) A full-scale prototype VHTR by about 2021; (2) High-temperature Brayton Cycle electric power production at full scale with a focus on economic performance; (3) Nuclear-assisted production of hydrogen (with about 10% of the heat) with a focus on economic performance; and (4) By test, the exceptional safety capabilities of the advanced gas-cooled reactors. Further, the NGNP program will: (1) Obtain a Nuclear Regulatory Commission (NRC) License to construct and operate the NGNP, this process will provide a basis for future performance based, risk-informed licensing; and (2) Support the development, testing, and prototyping of hydrogen infrastructures. The NGNP Materials Research and Development (R&D) Program is responsible for performing R&D on likely NGNP materials in support of the NGNP design, licensing, and construction activities. The NGNP Materials R&D Program includes the following elements: (1) Developing a specific approach, program plan and other project management tools for

  9. Advanced Hydrogen Transport Membranes for Vision 21 Fossil Fuel Plants

    Energy Technology Data Exchange (ETDEWEB)

    Carl R. Evenson; Shane E. Roark

    2006-03-31

    The objective of this project was to develop an environmentally benign, inexpensive, and efficient method for separating hydrogen from gas mixtures produced during industrial processes, such as coal gasification. A family of hydrogen separation membranes was developed including single phase mixed conducting ceramics, ceramic/ceramic composites, cermet membranes, cermet membranes containing a hydrogen permeable metal, and intermediate temperature composite layered membranes. Each membrane type had different operating parameters, advantages, and disadvantages that were documented over the course of the project. Research on these membranes progressed from ceramics to cermets to intermediate temperature composite layered membranes. During this progression performance was increased from 0.01 mL x min{sup -1} x cm{sup -2} up to 423 mL x min{sup -1} x cm{sup -2}. Eltron and team membranes not only developed each membrane type, but also membrane surface catalysis and impurity tolerance, creation of thin film membranes, alternative applications such as membrane promoted alkane dehydrogenation, demonstration of scale-up testing, and complete engineering documentation including process and mechanical considerations necessary for inclusion of Eltron membranes in a full scale integrated gasification combined cycle power plant. The results of this project directly led to a new $15 million program funded by the Department of Energy. This new project will focus exclusively on scale-up of this technology as part of the FutureGen initiative.

  10. A proposal for safety design philosophy of HTGR for coupling hydrogen production plant

    International Nuclear Information System (INIS)

    Sato, Hiroyuki; Ohashi, Hirofumi; Tazawa, Yujiro; Imai, Yoshiyuki; Nakagawa, Shigeaki; Tachibana, Yukio; Kunitomi, Kazuhiko

    2013-06-01

    Japan Atomic Energy Agency (JAEA) has been conducting research and development for hydrogen production utilizing heat from High Temperature Gas-cooled Reactors (HTGRs). Towards the realization of nuclear hydrogen production, coupled hydrogen production plants should not be treated as an extension of a nuclear plant in order to open the door for the entry of non-nuclear industries as well as assuring reactor safety against postulated abnormal events initiated in the hydrogen production plants. Since hydrogen production plant utilizing nuclear heat has never been built in the world, little attention has been given to the establishment of a safety design for such system including the High Temperature engineering Test Reactor (HTTR). In the present study, requirements in order to design, construct and operate hydrogen production plants under conventional chemical plant standards are identified. In addition, design considerations for safety design of nuclear facility are suggested. Furthermore, feasibility of proposed safety design and design considerations are evaluated. (author)

  11. Calculation of LUEC using HEEP Software for Nuclear Hydrogen Production Plant

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jongho; Lee, Kiyoung; Kim, Minhwan [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-05-15

    To achieve the hydrogen economy, it is very important to produce a massive amount of hydrogen in a clean, safe and efficient way. Nuclear production of hydrogen would allow massive production of hydrogen at economic prices while avoiding environments pollution by reducing the release of carbon dioxide. A Very High Temperature Reactor (VHTR) is considered as an efficient reactor to couple with the thermo-chemical Sulfur Iodine (SI) cycle to achieve the hydrogen economy. HEEP(Hydrogen Economy Evaluation Program) is one of the software tools developed by IAEA to evaluate the economy of the nuclear hydrogen production system by estimating unit hydrogen production cost. In this paper, the LUHC (Levelized Unit Hydrogen Cost) is calculated by using HEEP for nuclear hydrogen production plant, which consists of 4 modules of 600 MWth VHTR coupled with SI process. The levelized unit hydrogen production cost(LUHC) was calculated by the HEEP software.

  12. Spark Discharge Generated Nanoparticles for Hydrogen Storage Applications

    NARCIS (Netherlands)

    Vons, V.A.

    2010-01-01

    One of the largest obstacles to the large scale application of hydrogen powered fuel cell vehicles is the absence of hydrogen storage methods suitable for application on-board of these vehicles. Metal hydrides are materials in which hydrogen is reversibly absorbed by one or more metals or

  13. Safety Implementation of Hydrogen Igniters and Recombiners for Nuclear Power Plant Severe Accident Management

    Institute of Scientific and Technical Information of China (English)

    XIAO Jianjun; ZHOU Zhiwei; JING Xingqing

    2006-01-01

    Hydrogen combustion in a nuclear power plant containment building may threaten the integrity of the containment. Hydrogen recombiners and igniters are two methods to reduce hydrogen levels in containment buildings during severe accidents. The purpose of this paper is to evaluate the safety implementation of hydrogen igniters and recombiners. This paper analyzes the risk of deliberate hydrogen ignition and investigates three mitigation measures using igniters only, hydrogen recombiners only or a combination of recombiners and igniters. The results indicate that steam can effectively control the hydrogen flame acceleration and the deflagration-to-detonation transition.

  14. Improvements to thermal plants for generating energy

    International Nuclear Information System (INIS)

    Pacault, P.H.

    1975-01-01

    Said invention relates to a procedure for superheating steam intended for steam cycled thermal plants of energy production, and particularly nuclear power plants. Said procedure combines two different working modes. According to the first working mode, the live steam is taken from the steam generator, mechanically compressed and the heat is partly transferred to the working fluid. According to the second working mode the heat is taken from an auxiliary fluid heated by an independent thermal source, distinct from the principal thermal source of the plant and this heat is partly transferred to the working fluid. A combination of both working modes enables the superheating of the working fluid to be obtained before it inflows the turbine and/or between two stages of said turbine [fr

  15. Interfacial electrochemistry of colloidal ruthenium dioxide and catalysis of the photochemical generation of hydrogen from water

    NARCIS (Netherlands)

    Kleijn, J.M.

    1987-01-01

    The formation of hydrogen from water using solar energy is a very attractive research topic, because of the potential use of hydrogen as an alternative, clean fuel. It has been shown by many workers in the field that photochemical hydrogen generation can be achieved in an aqueous system,

  16. Operating of Small Wind Power Plants with Induction Generators

    OpenAIRE

    Jakub Nevrala; Stanislav Misak

    2008-01-01

    This paper describes different systems of small wind power plants with induction generators used in the Czech Republic. Problems of wind power plants running with induction generators are solved within partial target of the research project MSM 6198910007. For small wind power plants is used induction motor as a generator. Parameters of the name plate of motor must be resolved for generator running on measuring base. These generators are running as a separately working generators or generator...

  17. Nitrate removal from alkaline high nitrate effluent by in situ generation of hydrogen using zinc dust

    International Nuclear Information System (INIS)

    Rajagopal, S.; Chitra, S.; Paul, Biplob

    2016-01-01

    Alkaline radioactive low level waste generated in Nuclear Fuel Cycle contains substantial amount of nitrate and needs to be treated to meet Central Pollution Control Board discharge limits of 90 mg/L in marine coastal area. Several denitrification methods like chemical treatment, electrochemical reduction, biological denitrification, ion exchange, reverse osmosis, photochemical reduction etc are followed for removal of nitrate. In effluent treatment plants where chemical treatment is carried out, chemical denitrification can be easily adapted without any additional set up. Reducing agents like zinc and aluminum are suitable for reducing nitrate in alkaline solution. Study on denitrification with zinc dust was taken up in this work. Not much work has been done with zinc dust on reduction of nitrate to nitrogen in alkaline waste with high nitrate content. In the present work, nitrate is reduced by nascent hydrogen generated in situ, caused by reaction between zinc dust and sodium hydroxide

  18. Hydrogen generator, via catalytic partial oxidation of methane for fuel cells

    Science.gov (United States)

    Recupero, Vincenzo; Pino, Lidia; Di Leonardo, Raffaele; Lagana', Massimo; Maggio, Gaetano

    It is well known that the most acknowledged process for generation of hydrogen for fuel cells is based upon the steam reforming of methane or natural gas. A valid alternative could be a process based on partial oxidation of methane, since the process is mildly exothermic and therefore not energy intensive. Consequently, great interest is expected from conversion of methane into syngas, if an autothermal, low energy intensive, compact and reliable process could be developed. This paper covers the activities, performed by the CNR Institute of Transformation and Storage of Energy (CNR-TAE), on theoretical and experimental studies for a compact hydrogen generator, via catalytic selective partial oxidation of methane, integrated with second generation fuel cells (EC-JOU2 contract). In particular, the project focuses the attention on methane partial oxidation via heterogeneous selective catalysts, in order to: demonstrate the basic catalytic selective partial oxidation of methane (CSPOM) technology in a subscale prototype, equivalent to a nominal output of 5 kWe; develop the CSPOM technology for its application in electric energy production by means of fuel cells; assess, by a balance of plant analysis, and a techno-economic evaluation, the potential benefits of the CSPOM for different categories of fuel cells.

  19. Fluorinated cobalt for catalyzing hydrogen generation from sodium borohydride

    Energy Technology Data Exchange (ETDEWEB)

    Akdim, O.; Demirci, U.B.; Brioude, A.; Miele, P. [Laboratoire des Multimateriaux et Interfaces, UMR 5615 CNRS Universite Lyon 1, Universite de Lyon, 43 boulevard du 11 Novembre 1918, F-69622 Villeurbanne (France)

    2009-07-15

    The present paper reports preliminary results relating to a search for durable cobalt-based catalyst intended to catalyze the hydrolysis of sodium borohydride (NaBH{sub 4}). Fluorination of Co [Suda S, Sun YM, Liu BH, Zhou Y, Morimitsu S, Arai K, et al. Catalytic generation of hydrogen by applying fluorinated-metal hydrides as catalysts. Appl Phys A 2001; 72: 209-12.] has attracted our attention whereas the fluorination of Co boride has never been envisaged so far. Our first objective was to compare the reactivity of fluorinated Co with that of Co boride. We focused our attention on the formation of Co boride from fluorinated Co. Our second objective was to show the fluorination effect on the reactivity of Co. Our third objective was to find an efficient, durable Co catalyst. It was observed a limited stabilization of the Co surface by virtue of the fluorination, which made the formation of surface Co boride more difficult while the catalytic activity was unaltered. The fluorination did not affect the number of surface active sites. Nevertheless, it did not prevent the formation of Co boride. The fluorination of Co boride was inefficient. Hence, fluorination is a way to gain in stabilization of the catalytic surface but it is quite inefficient to hinder the boride formation. Accordingly, it did not permit to compare the reactivity of Co boride with that of Co. (author)

  20. Integrated photoelectrochemical energy storage: solar hydrogen generation and supercapacitor

    Science.gov (United States)

    Xia, Xinhui; Luo, Jingshan; Zeng, Zhiyuan; Guan, Cao; Zhang, Yongqi; Tu, Jiangping; Zhang, Hua; Fan, Hong Jin

    2012-01-01

    Current solar energy harvest and storage are so far realized by independent technologies (such as solar cell and batteries), by which only a fraction of solar energy is utilized. It is highly desirable to improve the utilization efficiency of solar energy. Here, we construct an integrated photoelectrochemical device with simultaneous supercapacitor and hydrogen evolution functions based on TiO2/transition metal hydroxides/oxides core/shell nanorod arrays. The feasibility of solar-driven pseudocapacitance is clearly demonstrated, and the charge/discharge is indicated by reversible color changes (photochromism). In such an integrated device, the photogenerated electrons are utilized for H2 generation and holes for pseudocapacitive charging, so that both the reductive and oxidative energies are captured and converted. Specific capacitances of 482 F g−1 at 0.5 A g−1 and 287 F g−1 at 1 A g−1 are obtained with TiO2/Ni(OH)2 nanorod arrays. This study provides a new research strategy for integrated pseudocapacitor and solar energy application. PMID:23248745

  1. Integrated photoelectrochemical energy storage: solar hydrogen generation and supercapacitor.

    Science.gov (United States)

    Xia, Xinhui; Luo, Jingshan; Zeng, Zhiyuan; Guan, Cao; Zhang, Yongqi; Tu, Jiangping; Zhang, Hua; Fan, Hong Jin

    2012-01-01

    Current solar energy harvest and storage are so far realized by independent technologies (such as solar cell and batteries), by which only a fraction of solar energy is utilized. It is highly desirable to improve the utilization efficiency of solar energy. Here, we construct an integrated photoelectrochemical device with simultaneous supercapacitor and hydrogen evolution functions based on TiO(2)/transition metal hydroxides/oxides core/shell nanorod arrays. The feasibility of solar-driven pseudocapacitance is clearly demonstrated, and the charge/discharge is indicated by reversible color changes (photochromism). In such an integrated device, the photogenerated electrons are utilized for H(2) generation and holes for pseudocapacitive charging, so that both the reductive and oxidative energies are captured and converted. Specific capacitances of 482 F g(-1) at 0.5 A g(-1) and 287 F g(-1) at 1 A g(-1) are obtained with TiO(2)/Ni(OH)(2) nanorod arrays. This study provides a new research strategy for integrated pseudocapacitor and solar energy application.

  2. Design option of heat exchanger for the next generation nuclear plant - HTR2008-58175

    International Nuclear Information System (INIS)

    Oh, C. H.; Kim, E. S.

    2008-01-01

    The Next Generation Nuclear Plant (NGNP), a very High temperature Gas-Cooled Reactor (VHTR) concept, will provide the first demonstration of a closed-loop Brayton cycle at a commercial scale, producing a few hundred megawatts of power in the form of electricity and hydrogen. The power conversion unit (PCU) for the NGNP will take advantage of the significantly higher reactor outlet temperatures of the VHTRs to provide higher efficiencies than can be achieved with the current generation of light water reactors. Besides demonstrating a system design that can be used directly for subsequent commercial deployment, the NGNP will demonstrate key technology elements that can be used in subsequent advanced power conversion systems for other Generation IV reactors. In anticipation of the design, development and procurement of an advanced power conversion system for the NGNP, the system integration of the NGNP and hydrogen plant was initiated to identify the important design and technology options that must be considered in evaluating the performance of the proposed NGNP. As part of the system integration of the VHTRs and the hydrogen production plant, the intermediate heat exchanger is used to transfer the process heat from VHTRs to the hydrogen plant. Therefore, the design and configuration of the intermediate heat exchanger is very important. This paper will include analysis of one stage versus two stage heat exchanger design configurations and simple stress analyses of a printed circuit heat exchanger (PCHE), helical coil heat exchanger, and shell/tube heat exchanger. (authors)

  3. Total generating costs: coal and nuclear plants

    International Nuclear Information System (INIS)

    1979-02-01

    The study was confined to single and multi-unit coal- and nuclear-fueled electric-generating stations. The stations are composed of 1200-MWe PWRs; 1200-MWe BWRs; 800-and 1200-MWe High-Sulfur Coal units, and 800- and 1200-MWe Low-Sulfur Coal units. The total generating cost estimates were developed for commercial operation dates of 1985 and 1990; for 5 and 8% escalation rates, for 10 and 12% discount rates; and, for capacity factors of 50, 60, 70, and 80%. The report describes the methodology for obtaining annualized capital costs, levelized coal and nuclear fuel costs, levelized operation and maintenance costs, and the resulting total generating costs for each type of station. The costs are applicable to a hypothetical Middletwon site in the Northeastern United States. Plant descriptions with general design parameters are included. The report also reprints for convenience, summaries of capital cost by account type developed in the previous commercial electric-power cost studies. Appropriate references are given for additional detailed information. Sufficient detail is given to allow the reader to develop total generating costs for other cases or conditions

  4. Hydrogen production by autothermal reforming of ethanol: pilot plant

    Energy Technology Data Exchange (ETDEWEB)

    Marin Neto, Antonio Jose; Camargo, Joao Carlos; Lopes, Daniel Gabriel; Ferreira, Paulo F.P. [Hydrogen Technology (HyTron), Campinas, SP (Brazil)], Email: antonio@hytron.com.br; Neves Junior, Newton Pimenta; Pinto, Edgar A. de Godoi Rodrigues; Silva, Ennio Peres da [Universidade Estadual de Campinas (DFA/ IFGW/UNICAMP), SP (Brazil). Inst. de Fisica Gleb Wataghin. Dept. de Fisica Aplicada; Furlan, Andre Luis [Universidade Estadual de Campinas (FEC/UNICAMP), SP (Brazil). Fac. de Engenharia Mecanica

    2010-07-01

    This work provides information about the development of an integrated unit for hydrogen production by auto thermal reforming of ethanol with nominal capacity of 1 kg/h H{sub 2} 4.5 (99.995%). The unit is composed by a Fuel Processing Module (FPM), resulting from auto thermal and shift reactor integration, responsible for the thermochemical step, plus an over heater of the liquid input (EtOH and H{sub 2}O), operated recovering thermal energy from PSA blown-down (H{sub 2} Purification Module - MPH2), besides other thermal equipment which completes the integration. Using a computational routine for scaling the process and preliminary performance analysis, it was possible to optimize operating conditions, essential along unit operations design. Likewise, performance estimation of the integrated unit proceeds, which shows efficiency about 72.5% from FPM. Coupled with the PSA recovery rate, 72.7%, the unit could achieve overall energy performance of 52.7%, or 74.4% working in co-generation of hydrogen and heat. (author)

  5. Hydrogen generation systems utilizing sodium silicide and sodium silica gel materials

    Science.gov (United States)

    Wallace, Andrew P.; Melack, John M.; Lefenfeld, Michael

    2015-07-14

    Systems, devices, and methods combine reactant materials and aqueous solutions to generate hydrogen. The reactant materials can sodium silicide or sodium silica gel. The hydrogen generation devices are used in fuels cells and other industrial applications. One system combines cooling, pumping, water storage, and other devices to sense and control reactions between reactant materials and aqueous solutions to generate hydrogen. Multiple inlets of varied placement geometries deliver aqueous solution to the reaction. The reactant materials and aqueous solution are churned to control the state of the reaction. The aqueous solution can be recycled and returned to the reaction. One system operates over a range of temperatures and pressures and includes a hydrogen separator, a heat removal mechanism, and state of reaction control devices. The systems, devices, and methods of generating hydrogen provide thermally stable solids, near-instant reaction with the aqueous solutions, and a non-toxic liquid by-product.

  6. Steam generators of Phenix: Measurement of the hydrogen concentration in sodium for detecting water leaks in the steam generator tubes

    International Nuclear Information System (INIS)

    Cambillard, E.; Lacroix, A.; Langlois, J.; Viala, J.

    1975-01-01

    The Phenix secondary circuits are provided with measurement systems of hydrogen concentration in sodium, that allow for the detection of possible water leaks in steam generators and the location of a faulty module. A measurement device consists of : a detector with nickel membranes of 0, 3 mm wall thickness, an ion pump with a 200 l/s flow rate, a quadrupole mass spectrometer and a calibrated hydrogen leak. The temperature correction is made automatically. The main tests carried out on the leak detection systems are reported. Since the first system operation (October 24, 1973), the measurements allowed us to obtain the hydrogen diffusion rates through the steam generator tube walls. (author)

  7. Hydrogen generation monitoring and mass gain analysis during the steam oxidation for Zircaloy using hydrogen and oxygen sensors

    International Nuclear Information System (INIS)

    Fukumoto, Michihisa; Hara, Motoi; Kaneko, Hiroyuki; Sakuraba, Takuya

    2015-01-01

    The oxidation behavior of Zircaloy-4 at high temperatures in a flowing Ar-H_2O (saturated at 323 K) mixed gas was investigated using hydrogen and oxygen sensors installed at a gas outlet, and the utility of the gas sensing methods by using both sensors was examined. The generated amount of hydrogen was determined from the hydrogen partial pressure continuously measured by the hydrogen sensor, and the resultant calculated oxygen amount that reacted with the specimen was in close agreement with the mass gain gravimetrically measured after the experiment. This result demonstrated that the hydrogen partial pressure measurement using a hydrogen sensor is an effective method for examining the steam oxidation of this metal as well as monitoring the hydrogen evolution. The advantage of this method is that the oxidation rate of the metal at any time as a differential quantity is able to be obtained, compared to the oxygen amount gravimetrically measured as an integral quantity. When the temperature was periodically changed in the range of 1173 K to 1523 K, highly accurate measurements could be carried out using this gas monitoring method, although reasonable measurements were not gravimetrically performed due to the fluctuating thermo-buoyancy during the experiment. A change of the oxidation rate was clearly detected at a monoclinic tetragonal transition temperature of ZrO_2. From the calculation of the water vapor partial pressure during the thermal equilibrium condition using the hydrogen and oxygen partial pressures, it became clear that a thermal equilibrium state is maintained when the isothermal condition is maintained, but is not when the temperature increases or decreases with time. Based on these results, it was demonstrated that the gas monitoring system using hydrogen and oxygen sensors is very useful for investigating the oxidation process of the Zircaloy in steam. (author)

  8. Micro hydrogen for portable power : generating opportunities for hydrogen and fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2006-07-01

    A new fuel cell technology for portable applications was reviewed. Success for the fuel cell industry will be achieved primarily by supplanting lithium-ion batteries, and fuel cells for portable applications have clear advantages to batteries in addition to their known environmental benefits. Micro hydrogen {sup TM} is the integrated combination of hydrogen fuel cell, hydrogen storage and delivery, fluidic interconnects and power conditioning electronics required for creating high energy density portable power sources. The small size, low heat production, environmental sustainability and refueling flexibility of the systems provides enormous economic opportunities for the use of micro hydrogen in cell phone technology, personal digital assistants and other electronic gadgets. Details of a trial to test and evaluate micro hydrogen fuel cell powered bike lights were presented. Further programs are planned for external demonstrations of high-beam search and rescue lighting, flashlights for security personnel and portable hydrogen power sources that will be used by multiple organizations throughout British Columbia. It was concluded that fuel cell technology must match the lithium-ion battery's performance by providing fast recharge, high energy density, and adaptability. Issues concerning refueling and portable and disposable cartridges for micro hydrogen systems were also discussed. 8 figs.

  9. French nuclear power plants for heat generation

    International Nuclear Information System (INIS)

    Girard, Y.

    1984-01-01

    The considerable importance that France attributes to nuclear energy is well known even though as a result of the economic crisis and the energy savings it is possible to observe a certain downward trend in the rate at which new power plants are being started up. In July 1983, a symbolic turning-point was reached - at more than 10 thousand million kW.h nuclear power accounted, for the first time, for more than 50% of the total amount of electricity generated, or approx. 80% of the total electricity output of thermal origin. On the other hand, the direct contribution - excluding the use of electricity - of nuclear energy to the heat market in France remains virtually nil. The first part of this paper discusses the prospects and realities of the application, at low and intermediate temperatures, of nuclear heat in France, while the second part describes the French nuclear projects best suited to the heat market (excluding high temperatures). (author)

  10. Vogtle Electric Generating Plant ETE Analysis Review

    Energy Technology Data Exchange (ETDEWEB)

    Diediker, Nona H.; Jones, Joe A.

    2006-12-09

    Under contract with the Nuclear Regulatory Commission (NRC), staff from Pacific Northwest National Laboratory (PNNL) and Sandia National Laboratory (SNL)-Albuquerque reviewed the evacuation time estimate (ETE) analysis dated April 2006 prepared by IEM for the Vogtle Electric Generating Plant (VEGP). The ETE analysis was reviewed for consistency with federal regulations using the NRC guidelines in Review Standard (RS)-002, Supplement 2 and Appendix 4 to NUREG-0654, and NUREG/CR-4831. Additional sources of information referenced in the analysis and used in the review included NUREG/CR-6863 and NUREG/CR-6864. The PNNL report includes general comments, data needs or clarifications, and requests for additional information (RAI) resulting from review of the ETE analysis.

  11. Wind power plant for electricity generation

    Energy Technology Data Exchange (ETDEWEB)

    Landsiedel, E

    1978-11-09

    The invention concerns a wind power plant which rotates on a vertical axis and is suitable for the generation of electricity. This wind power machine with a vertical axis can be mounted at any height, so that it can catch the wind on the vertical axis of rotation. Further, it does not have to be turned into the direction of the wind and fixed. The purpose of the invention is to obtain equal load on the structure due to the vertical axis. The purpose of the invention is fulfilled by having the wind vanes fixed above one another from the bottom to the top in 6 different directions. The particular advantage of the invention lies in the fact that the auxiliary blades can bring the other blades to the operating position in good time, due to their particular method of fixing.

  12. Analysis of an Improved Solar-Powered Hydrogen Generation System for Sustained Renewable Energy Production

    Science.gov (United States)

    2017-12-01

    hydrogen gas by electrolysis. In LT Aviles’ design , distilled water was collected from the ambient air using Peltier dehumidifiers, manufactured by...Figure 13 shows the shelfing along with the entire system. Figure 13. Reconfigured Hydrogen Production Facility Because the system was designed for...POWERED HYDROGEN GENERATION SYSTEM FOR SUSTAINED RENEWABLE ENERGY PRODUCTION by Sen Feng Yu December 2017 Thesis Advisor: Garth V. Hobson Co

  13. Engineering Design Elements of a Two-Phase Thermosyphon to Trannsfer NGNP Nuclear Thermal Energy to a Hydrogen Plant

    Energy Technology Data Exchange (ETDEWEB)

    Piyush Sabharwal

    2009-07-01

    Two hydrogen production processes, both powered by a Next Generation Nuclear Plant (NGNP), are currently under investigation at Idaho National Laboratory. The first is high-temperature steam electrolysis, which uses both heat and electricity; the second is thermo-chemical production through the sulfur iodine process primarily using heat. Both processes require a high temperature (>850°C) for enhanced efficiency; temperatures indicative of the NGNP. Safety and licensing mandates prudently dictate that the NGNP and the hydrogen production facility be physically isolated, perhaps requiring separation of over 100 m.

  14. The application of CFD to hydrogen risk analysis in nuclear power plants

    International Nuclear Information System (INIS)

    Wang Hui; Han Xu; Chang Meng; Wang Xiaofeng; Wang Shuguo; Lu Xinhua; Wu Lin

    2013-01-01

    Status of the hydrogen risk analysis method is systemically summarized in this paper and the advantages and limits of CFD (Computational Fluid Dynamic) in hydrogen risk analysis is discussed. The international experimental programs on the CFD hydrogen risk analysis are introduced in this paper. The application of CFD to nuclear power plant (NPP) hydrogen risk analysis is introduced in detail by taking EPR and Ling'ao NPP for example. In these bases, the CFD development prospect of hydrogen risk analysis is also summarized in this paper. (authors)

  15. Options for helium circulation in a hydrogen production plant VHTR-Si: thermal-economic comparative

    International Nuclear Information System (INIS)

    Mendoza A, A.; Francois L, J. L.; Anaya D, A.

    2011-11-01

    The technologies that take advantage of the heat of nuclear reactors of IV generation are of great interest, due to their high energy efficiencies and to their strong economic potential. An example of these technologies is the sulfur-iodine process coupled to a nuclear reactor of high temperature cooled by helium. In this process heat is transferred from the nuclear reactor to the chemical plant by means of two cycles of helium interconnected by an intermediate heat exchanger. The first, denominated primary cycle of cooling, removes the heat of the nuclear reactor, transferring to the secondary cycle to be distributed to equipment s in the chemical plant. The pass of the helium gas through the equipment s that compose each one of the cycles, implies pressure losses that should be compensated necessarily by re-compression to maintain a stable state in the system, causing the energy consumption, usually rejected in the energy analyses. When to this energy is added the energy required in the hydrogen plant: energy required by the pumping systems, will decrease the efficiency of the nucleus-chemical complex, increasing the even cost of the hydrogen. In this work, three options to supply the compression energy and pumping (CEP) to the system are proposed, and these are analyzed thermodynamic and economically. The results indicate that to consider the CEP in the economic analysis increases between 1.5 and 3% the even cost of the hydrogen, and that the option with more energy efficiency is not necessarily the best for the nucleus-chemical complex. (Author)

  16. Hydrogen peroxide homeostasis: activation of plant catalase by calcium/calmodulin

    Science.gov (United States)

    Yang, T.; Poovaiah, B. W.

    2002-01-01

    Environmental stimuli such as UV, pathogen attack, and gravity can induce rapid changes in hydrogen peroxide (H(2)O(2)) levels, leading to a variety of physiological responses in plants. Catalase, which is involved in the degradation of H(2)O(2) into water and oxygen, is the major H(2)O(2)-scavenging enzyme in all aerobic organisms. A close interaction exists between intracellular H(2)O(2) and cytosolic calcium in response to biotic and abiotic stresses. Studies indicate that an increase in cytosolic calcium boosts the generation of H(2)O(2). Here we report that calmodulin (CaM), a ubiquitous calcium-binding protein, binds to and activates some plant catalases in the presence of calcium, but calcium/CaM does not have any effect on bacterial, fungal, bovine, or human catalase. These results document that calcium/CaM can down-regulate H(2)O(2) levels in plants by stimulating the catalytic activity of plant catalase. Furthermore, these results provide evidence indicating that calcium has dual functions in regulating H(2)O(2) homeostasis, which in turn influences redox signaling in response to environmental signals in plants.

  17. Selective Electrochemical Generation of Hydrogen Peroxide from Water Oxidation

    DEFF Research Database (Denmark)

    Viswanathan, Venkatasubramanian; Hansen, Heine Anton; Nørskov, Jens K.

    2015-01-01

    evolution and form hydrogen peroxide. Using density functional theory calculations, we show that the free energy of adsorbed OH* can be used to determine selectivity trends between the 2e(-) water oxidation to H2O2 and the 4e(-) oxidation to O2. We show that materials which bind oxygen intermediates...... sufficiently weakly, such as SnO2, can activate hydrogen peroxide evolution. We present a rational design principle for the selectivity in electrochemical water oxidation and identify new material candidates that could perform H2O2 evolution selectively....

  18. 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%

  19. Physiological behavior of hydrogen sulfide in rice plant. Part 5. Effect of hydrogen sulfide on respiration of rice roots

    Energy Technology Data Exchange (ETDEWEB)

    Okajima, H; Takagi, S

    1955-01-01

    The inhibitory effects of hydrogen sulfide on the respiration of rice plant roots were investigated using Warburg's manometory technique. Hydrogen sulfide inhibited not only aerobic respiration but anaerobic respiration process of roots. Inhibitory action of hydrogen sulfide and potassium cyanide on the respiration were apparently reversible, but the style of recovery reaction from inhibition was somewhat different in each case. Oxygen consumption of roots was increased by addition of ammonium salts, but the same effects were not recognized by the addition of any other salt examined (except nitrate salts). There was close relationship between respiration of roots and assimilation of nitrogen by roots. The increased oxygen uptake by addition of ammonium salt was also inhibited by hydrogen sulfide. The reactivation of this reaction occurred with the recovery of endogenous respiration of roots. 19 references, 8 figures, 3 tables.

  20. Analysis of Hydrogen Generation and Accumulation in U-233 Tube Vaults

    International Nuclear Information System (INIS)

    Ally, M.R.; Willis, K.J.

    1999-01-01

    The purpose of the 233 U Safe Storage Program is to enhance the safe storage of 233 U-bearing materials. This report describes the work done at the Oak Ridge National Laboratory's Radiochemical Development Facility (RDF) to address questions related to possible hydrogen generation and accumulation in 233 U tube vaults. The objective of this effort was to verify assumptions in the mathematical model used to estimate the hydrogen content of the gaseous atmosphere that possibly could occur inside the tube vaults in Building 3019 and to evaluate proposed measures for mitigating any hydrogen concerns. A mathematical model was developed using conservative assumptions to evaluate possible hydrogen generation and accumulation in the tube vaults. The model concluded that an equilibrium concentration would be established below the lower flammability limit (LFL) of 4.1% hydrogen. The major assumptions used in the model that were validated are as follows: (1) The shield plug does not form a seal with the tube vault wall, thus allowing the hydrogen gas to diffuse past the shield plug to the upper section of the tube vault. (2) The tube vault end-cap leaks sufficiently to allow air to be drawn into the tube vault by the off-gas system, thereby purging hydrogen from the upper section of the tube vault. (3) Any hydrogen gas generated completely mixes with the other gases present in the lower section of the tube vault and does not stratify beneath the shield plug. (4) The diffusion coefficient determined from the literature for constant diffusion of hydrogen in air is valid. The coefficient is corrected for temperatures from 0 to 25 C. Another assumption used in the model, that hydrogen generated by radiolytic decomposition of hydrogen-bearing materials (e.g., moisture and plastic) leaks from the cans under steady-state condition, as opposed to a sudden release resulting from rupture of the can(s), was beyond the scope of this investigation. Several parameters from the original

  1. Utilization of hydrogen gas production for electricity generation in ...

    African Journals Online (AJOL)

    Lecturer

    2012-05-03

    May 3, 2012 ... The main goals of this research were to use E. aerogenes ADH-43 for fermentation in order to decide the best carbon sources and ... by converting to electricity using fuel cells in 50 ml vial bottle, 2% total ... evolution compared with other biological hydrogen .... Erlenmeyer containing a solution of Ca (OH) 2.

  2. Solar-hydrogen generation and solar concentration (Conference Presentation)

    NARCIS (Netherlands)

    Sulima, Oleg V.; Chinello, Enrico; Conibeer, Gavin; Modestino, Miquel A.; Schüttauf, Jan-Willem; Lambelet, David; Delfino, Antonio; Domine, Didier; Faes, Antonin; Despeisse, Matthieu; Bailat, Julien; Psaltis, Demetri; Fernandez Rivas, David; Ballif, Christophe; Moser, Christophe

    2016-01-01

    We successfully demonstrated and reported the highest solar-to-hydrogen efficiency with crystalline silicon cells and Earth-abundant electrocatalysts under unconcentrated solar radiation. The combination of hetero-junction silicon cells and a 3D printed Platinum/Iridium-Oxide electrolyzer has been

  3. Solar photocatalytic generation of hydrogen under ultraviolet-visible ...

    Indian Academy of Sciences (India)

    Administrator

    solar energy has been regarded as an attractive solution to resolve the global energy ... simultaneous hydrogen production and H2S decomposi- tion is a highly ... of CdCO3 and ZnCO3 in dilute acetic acid at 60–70°C. Mixing slowly the hot ...

  4. Hydrogen generation from aluminium corrosion in reactor containment spray solutions

    International Nuclear Information System (INIS)

    Frid, W.; Karlberg, G.; Sundvall, S.B.

    1982-01-01

    The aluminium corrosion experiments in reactor containment spray solutions, under the conditions expected to prevail during LOCA in BWR and PWR, were performed in order to investigate relationships between temperature, pH and hydrogen production rates. In order to simulate the conditions in a BWR containment realistic ratios between aluminium surface and water volume and between aluminium surface and oxygen volume were used. Three different aluminium alloys were exposed to spray solutions: AA 1050, AA 5052 and AA 6082. The corrosion rates were measured for BWR solutions (deaerated and aerated) with pH 5 and 9 at 50, 100 and 150 0 C. The pressure was constantly 0.8 MPa. The hydrogen production rate was measured by means of gas chromatography. In deionized BWR water the corrosion rates did not exceed about 0.05 mm/year in all cases, i.e. were practically independent of temperature and pH. Hydrogen concentrations were less than 0.1 vol.% in cooled dry gas. Corrosion rates and hydrogen production in PWR alkaline solution measured at pH 9.7 and 150 0 C were very high. AA 5052 alloy was the best material

  5. HOGEN{trademark} proton exchange membrane hydrogen generators: Commercialization of PEM electrolyzers

    Energy Technology Data Exchange (ETDEWEB)

    Smith, W.F.; Molter, T.M. [Proton Energy Systems, Inc., Rocky Hill, CT (United States)

    1997-12-31

    PROTON Energy Systems` new HOGEN series hydrogen generators are Proton Exchange Membrane (PEM) based water electrolyzers designed to generate 300 to 1000 Standard Cubic Feet Per Hour (SCFH) of high purity hydrogen at pressures up to 400 psi without the use of mechanical compressors. This paper will describe technology evolution leading to the HOGEN, identify system design performance parameters and describe the physical packaging and interfaces of HOGEN systems. PEM electrolyzers have served US and UK Navy and NASA needs for many years in a variety of diverse programs including oxygen generators for life support applications. In the late 1970`s these systems were advocated for bulk hydrogen generation through a series of DOE sponsored program activities. During the military buildup of the 1980`s commercial deployment of PEM hydrogen generators was de-emphasized as priority was given to new Navy and NASA PEM electrolysis systems. PROTON Energy Systems was founded in 1996 with the primary corporate mission of commercializing PEM hydrogen generators. These systems are specifically designed and priced to meet the needs of commercial markets and produced through manufacturing processes tailored to these applications. The HOGEN series generators are the first step along the path to full commercial deployment of PEM electrolyzer products for both industrial and consumer uses. The 300/1000 series are sized to meet the needs of the industrial gases market today and provide a design base that can transition to serve the needs of a decentralized hydrogen infrastructure tomorrow.

  6. Noble metal catalyzed hydrogen generation from formic acid in nitrite-containing simulated nuclear waste media

    International Nuclear Information System (INIS)

    King, R.B.; Bhattacharyya, N.K.; Wiemers, K.D.

    1994-08-01

    Simulants for the Hanford Waste Vitrification Plant (HWVP) feed containing the major non-radioactive components Al, Cd, Fe, Mn, Nd, Ni, Si, Zr, Na, CO 3 2- , NO 3 -, and NO 2 - were used as media to evaluate the stability of formic acid towards hydrogen evolution by the reaction HCO 2 H → H 2 + CO 2 catalyzed by the noble metals Ru, Rh, and/or Pd found in significant quantities in uranium fission products. Small scale experiments using 40-50 mL of feed simulant in closed glass reactors (250-550 mL total volume) at 80-100 degree C were used to study the effect of nitrite and nitrate ion on the catalytic activities of the noble metals for formic acid decomposition. Reactions were monitored using gas chromatography to analyze the CO 2 , H 2 , NO, and N 2 O in the gas phase as a function of time. Rhodium, which was introduced as soluble RhCl 3 ·3H 2 O, was found to be the most active catalyst for hydrogen generation from formic acid above ∼80 degree C in the presence of nitrite ion in accord with earlier observations. The inherent homogeneous nature of the nitrite-promoted Rh-catalyzed formic acid decomposition is suggested by the approximate pseudo first-order dependence of the hydrogen production rate on Rh concentration. Titration of the typical feed simulants containing carbonate and nitrite with formic acid in the presence of rhodium at the reaction temperature (∼90 degree C) indicates that the nitrite-promoted Rh-catalyzed decomposition of formic acid occurs only after formic acid has reacted with all of the carbonate and nitrite present to form CO 2 and NO/N 2 O, respectively. The catalytic activities of Ru and Pd towards hydrogen generation from formic acid are quite different than those of Rh in that they are inhibited rather than promoted by the presence of nitrite ion

  7. Operation of the cryotron relaxation generator in solid argon and hydrogen

    International Nuclear Information System (INIS)

    Rakhubvsky, V.A.

    2008-01-01

    The research results of the cryotron relaxation generator (CRG) operation in solid argon, normal hydrogen and parahydrogen have been given. The frequency transition times for CRG at different values of cooling the solid gas have been measured

  8. Workshop on Hydrogen Storage and Generation for Medium-Power and -Energy Applications

    National Research Council Canada - National Science Library

    Matthews, Michael

    1998-01-01

    This report summarizes the Workshop on Hydrogen Storage and Generation Technologies for Medium-Power and -Energy Applications which was held on April 8-10, 1997 at the Radisson Hotel Orlando Airport in Orlando, Florida...

  9. ENVIRONMENTAL TECHNOLOGY VERIFICATION REPORT: BIOQUELL, INC. CLARIS C HYDROGEN PEROXIDE GAS GENERATOR

    Science.gov (United States)

    The Environmental Technology Verification report discusses the technology and performance of the Clarus C Hydrogen Peroxide Gas Generator, a biological decontamination device manufactured by BIOQUELL, Inc. The unit was tested by evaluating its ability to decontaminate seven types...

  10. Next Generation Hydrogen Station Composite Data Products: Retail Stations, Data through Quarter 4 of 2016

    Energy Technology Data Exchange (ETDEWEB)

    Sprik, Sam [National Renewable Energy Lab. (NREL), Golden, CO (United States); Kurtz, Jennifer [National Renewable Energy Lab. (NREL), Golden, CO (United States); Ainscough, Chris [National Renewable Energy Lab. (NREL), Golden, CO (United States); Saur, Genevieve [National Renewable Energy Lab. (NREL), Golden, CO (United States); Peters, Michael [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2017-05-31

    This publication includes 86 composite data products (CDPs) produced for next generation hydrogen stations, with data through the fourth quarter of 2016. These CDPs include data from retail stations only.

  11. Next Generation Hydrogen Station Composite Data Products: Retail Stations, Data through Quarter 2 of 2017

    Energy Technology Data Exchange (ETDEWEB)

    Sprik, Samuel [National Renewable Energy Lab. (NREL), Golden, CO (United States); Kurtz, Jennifer M [National Renewable Energy Lab. (NREL), Golden, CO (United States); Ainscough, Christopher D. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Saur, Genevieve [National Renewable Energy Lab. (NREL), Golden, CO (United States); Peters, Michael C. [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2017-12-05

    This publication includes 92 composite data products (CDPs) produced for next generation hydrogen stations, with data through the second quarter of 2017. These CDPs include data from retail stations only.

  12. Hydrogen treatment system in the Genkai nuclear power plant No. 2

    International Nuclear Information System (INIS)

    Nakamura, Masayuki; Kodama, Hideo; Murashima, Masayasu

    1977-01-01

    The new hydrogen treatment system which injects hydrogen into the volume control tank for purging the mixed waste gas of Kr, Xe, etc. is adopted in the Genkai nuclear power plant No. 2. The system is composed of mainly the waste gas pretreatment equipment, a palladium alloy membrane type hydrogen separator, a hydrogen compressor, and a waste gas decay tank. The outline of the primary cooling system and the chemical volume control system of PWR, the hydrogen treatment system, and the gaseous waste disposal system of original and new types for the Genkai nuclear power plants No. 1 and 2 are explained in this paper. This newly added hydrogen treatment system will be able to reduce the rare gas concentration rate in the primary coolant to about 1/2 and 1/5 for Kr 85 and Xe 133 , respectively. (auth.)

  13. Multi-unit Inertial Fusion Energy (IFE) plants producing hydrogen fuel

    International Nuclear Information System (INIS)

    Logan, B.G.

    1993-12-01

    A quantitative energy pathway comparison is made between a modern oil refinery and genetic fusion hydrogen plant supporting hybrid-electric cars powered by gasoline and hydrogen-optimized internal combustion engines, respectively, both meeting President Clinton's goal for advanced car goal of 80 mpg gasoline equivalent. The comparison shows that a fusion electric plant producing hydrogen by water electrolysis at 80% efficiency must have an electric capacity of 10 GWe to support as many hydrogen-powered hybrid cars as one modern 200,000 bbl/day-capacity oil refinery could support in gasoline-powered hybrid cars. A 10 GWe fusion electric plant capital cost is limited to 12.5 B$ to produce electricity at 2.3 cents/kWehr, and hydrogen production by electrolysis at 8 $/GJ, for equal consumer fuel cost per passenger mile as in the oil-gasoline-hybrid pathway

  14. Sensor for Measuring Hydrogen Partial Pressure in Parabolic Trough Power Plant Expansion Tanks

    Energy Technology Data Exchange (ETDEWEB)

    Glatzmaier, Greg C.; Cooney, Daniel A.

    2017-06-27

    The National Renewable Energy Laboratory and Acciona Energy North America are working together to design and implement a process system that provides a permanent solution to the issue of hydrogen buildup at parabolic trough power plants. We are pursuing a method that selectively removes hydrogen from the expansion tanks that serve as reservoirs for the heat transfer fluid (HTF) that circulates in the collector field and power block components. Our modeling shows that removing hydrogen from the expansion tanks at a design rate reduces and maintains dissolved hydrogen in the circulating HTF to a selected target level. Our collaborative work consists of several tasks that are needed to advance this process concept to a development stage, where it is ready for implementation at a commercial power plant. Our main effort is to design and evaluate likely process-unit operations that remove hydrogen from the expansion tanks at a specified rate. Additionally, we designed and demonstrated a method and instrumentation to measure hydrogen partial pressure and concentration in the expansion-tank headspace gas. We measured hydrogen partial pressure in the headspace gas mixture using a palladium-alloy membrane, which is permeable exclusively to hydrogen. The membrane establishes a pure hydrogen gas phase that is in equilibrium with the hydrogen in the gas mixture. We designed and fabricated instrumentation, and demonstrated its effectiveness in measuring hydrogen partial pressures over a range of three orders of magnitude. Our goal is to install this instrument at the Nevada Solar One power plant and to demonstrate its effectiveness in measuring hydrogen levels in the expansion tanks under normal plant operating conditions.

  15. Hydrogen generation and storage from hydrolysis of sodium borohydride in batch reactors

    Energy Technology Data Exchange (ETDEWEB)

    Pinto, A.M.F.R.; Falcao, D.S. [Departamento de Eng. Quimica, Centro de Estudos de Fenomenos de Transporte, Faculdade de Engenharia da Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto (Portugal); Silva, R.A.; Rangel, C.M. [Instituto Nacional de Engenharia e Tecnologia e Inovacao, Paco do Lumiar 22, 1649-038 (Portugal)

    2006-08-15

    The catalytic hydrolysis of alkaline sodium borohydride (NaBH{sub 4}) solution was studied using a non-noble; nickel-based powered catalyst exhibiting strong activity even after long time storage. This easy-to-prepare catalyst showed an enhanced activity after being recovered from previous use. The effects of temperature, NaBH{sub 4} concentration, NaOH concentration and pressure on the hydrogen generation rate were investigated. Particular importance has the effect of pressure, since the maximum reached pressure of hydrogen is always substantially lower than predictions (considering 100% conversion) due to solubility effects. The solubility of hydrogen is greatly enhanced by the rising pressure during reaction, leading to storage of hydrogen in the liquid phase. This effect can induce new ways of using this type of catalyst and reactor for the construction of hydrogen generators and even containers for portable and in situ applications. (author)

  16. 7 CFR 1726.125 - Generating plant facilities.

    Science.gov (United States)

    2010-01-01

    ... desulfurization system, particulate removal system, electric wiring and control systems, mechanical equipment installation (including turbine installation and plant piping), power plant building (foundation and... installations. Engineering services, turbine/generator, civil works and powerhouse construction, electrical...

  17. Assessment of productivity at four generating plants

    International Nuclear Information System (INIS)

    Saarlas, M.; Nelson, M.

    1976-01-01

    The 1975 FEA study of power plant reliability was undertaken as a first step in improving the productivity of large (larger than 400 MW) generating units by attempting to trace outages to their root causes so that meaningful corrective action can be taken at the root of the problem. Trident Engineering Associates studied the operation, maintenance, management, and manning of two fossil-fueled and two nuclear-fueled units, one each of above average and one below average reliability (high availability and low forced outage rate). It was expected that the differences between a highly reliable unit and a less reliable unit would lead to recommendations which would be useful for improving productivity of units throughout the country. The findings are of two basic types: (1) general concepts covering problem areas, fundamental reasons and immediate symptoms behind the problems, methods used to eliminate or alleviate the problems, and proposed solutions; (2) details which provide statistics that establish the relative lost productivity by fundamental causes. Eight root causes (fundamental reasons for failures or outages) were established into which most failures and outages could be assigned. Twenty nine cause factors (causes of failure) were established which assisted in assigning the failures and outages to a root cause

  18. Hydrogen generation through static-feed water electrolysis

    Science.gov (United States)

    Jensen, F. C.; Schubert, F. H.

    1975-01-01

    A static-feed water electrolysis system (SFWES), developed under NASA sponsorship, is presented for potential applicability to terrestrial hydrogen production. The SFWES concept uses (1) an alkaline electrolyte to minimize power requirements and materials-compatibility problems, (2) a method where the electrolyte is retained in a thin porous matrix eliminating bulk electrolyte, and (3) a static water-feed mechanism to prevent electrode and electrolyte contamination and to promote system simplicity.

  19. Volume generation of negative ions in high density hydrogen discharges

    International Nuclear Information System (INIS)

    Hiskes, J.R.; Karo, A.M.

    1983-01-01

    A parametric survey is made of a high-density tandem two-chamber hydrogen negative ion system. The optimum extracted negative ion current densities are sensitive to the atom concentration in the discharge and to the system scale length. For scale lengths ranging from 10 cm to 0.1 cm optimum current densities range from of order 1 to 100 mA cm -2 , respectively

  20. Wind power generation plant installed on cargo ship and marine resources recovery by seawater electrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Murahara, M. [Tokyo Inst. of Technology, Tokyo (Japan)]|[Tokai Univ., Hiratsuka, Kanagawa (Japan); Seki, K. [Mingdao Univ., Taiwan (China)]|[Tokai Univ., Hiratsuka, Kanagawa (Japan). Research Inst. of Science and Technology

    2008-07-01

    Transmission loss from offshore wind turbine arrays is directly proportional to the length of the cable that brings power onshore. In order to minimize transmission loss, wind-generated electricity needs to be stored temporarily in a different form. Seawater, rock salt, and water of saline lakes can be desalinated and then electrolyzed to produce hydrogen. This paper presented a new method of offshore sodium production in Japan by seawater electrolysis. In this technique, sodium is manufactured on site by molten-salt electrolysis as a solid fuel. Sodium is electrolytically collected from the seawater or rock salt by the wind power generation. The sodium is then transported to a hydrogen power plant on land and then is added water to generate hydrogen for operating a hydrogen combustion turbine. The sodium hydroxide by-product is then supplied to the soda industry as a raw material. In seawater electrolysis, not only sodium but also fresh water, magnesium, calcium, potassium, sodium hydroxide, chlorine, oxygen, hydrogen, hydrochloric acid, and sulfuric acid are isolated and recovered as by-products. 5 refs., 6 figs.

  1. Characteristics of Hydrogen Monitoring Systems for Severe Accident Management at a Nuclear Power Plant

    Science.gov (United States)

    Petrosyan, V. G.; Yeghoyan, E. A.; Grigoryan, A. D.; Petrosyan, A. P.; Movsisyan, M. R.

    2018-02-01

    One of the main objectives of severe accident management at a nuclear power plant is to protect the integrity of the containment, for which the most serious threat is possible ignition of the generated hydrogen. There should be a monitoring system providing information support of NPP personnel, ensuring data on the current state of a containment gaseous environment and trends in its composition changes. Monitoring systems' requisite characteristics definition issues are considered by the example of a particular power unit. Major characteristics important for proper information support are discussed. Some features of progression of severe accident scenarios at considered power unit are described and a possible influence of the hydrogen concentration monitoring system performance on the information support reliability in a severe accident is analyzed. The analysis results show that the following technical characteristics of the combustible gas monitoring systems are important for the proper information support of NPP personnel in the event of a severe accident at a nuclear power plant: measured parameters, measuring ranges and errors, update rate, minimum detectable concentration of combustible gas, monitoring reference points, environmental qualification parameters of the system components. For NPP power units with WWER-440/270 (230) type reactors, which have a relatively small containment volume, the update period for measurement results is a critical characteristic of the containment combustible gas monitoring system, and the choice of monitoring reference points should be focused not so much on the definition of places of possible hydrogen pockets but rather on the definition of places of a possible combustible mixture formation. It may be necessary for the above-mentioned power units to include in the emergency operating procedures measures aimed at a timely heat removal reduction from the containment environment if there are signs of a severe accident phase

  2. Hydrogen generation using silicon nanoparticles and their mixtures with alkali metal hydrides

    Science.gov (United States)

    Patki, Gauri Dilip

    Hydrogen is a promising energy carrier, for use in fuel cells, engines, and turbines for transportation or mobile applications. Hydrogen is desirable as an energy carrier, because its oxidation by air releases substantial energy (thermally or electrochemically) and produces only water as a product. In contrast, hydrocarbon energy carriers inevitably produce CO2, contributing to global warming. While CO2 capture may prove feasible in large stationary applications, implementing it in transportation and mobile applications is a daunting challenge. Thus a zero-emission energy carrier like hydrogen is especially needed in these cases. Use of H2 as an energy carrier also brings new challenges such as safe handling of compressed hydrogen and implementation of new transport, storage, and delivery processes and infrastructure. With current storage technologies, hydrogen's energy per volume is very low compared to other automobile fuels. High density storage of compressed hydrogen requires combinations of high pressure and/or low temperature that are not very practical. An alternative for storage is use of solid light weight hydrogenous material systems which have long durability, good adsorption properties and high activity. Substantial research has been conducted on carbon materials like activated carbon, carbon nanofibers, and carbon nanotubes due to their high theoretical hydrogen capacities. However, the theoretical values have not been achieved, and hydrogen uptake capacities in these materials are below 10 wt. %. In this thesis we investigated the use of silicon for hydrogen generation. Hydrogen generation via water oxidation of silicon had been ignored due to slow reaction kinetics. We hypothesized that the hydrogen generation rate could be improved by using high surface area silicon nanoparticles. Our laser-pyrolysis-produced nanoparticles showed surprisingly rapid hydrogen generation and high hydrogen yield, exceeding the theoretical maximum of two moles of H2 per

  3. Hydrogen generation systems and methods utilizing sodium silicide and sodium silica gel materials

    Energy Technology Data Exchange (ETDEWEB)

    Wallace, Andrew P.; Melack, John M.; Lefenfeld, Michael

    2017-12-19

    Systems, devices, and methods combine thermally stable reactant materials and aqueous solutions to generate hydrogen and a non-toxic liquid by-product. The reactant materials can sodium silicide or sodium silica gel. The hydrogen generation devices are used in fuels cells and other industrial applications. One system combines cooling, pumping, water storage, and other devices to sense and control reactions between reactant materials and aqueous solutions to generate hydrogen. Springs and other pressurization mechanisms pressurize and deliver an aqueous solution to the reaction. A check valve and other pressure regulation mechanisms regulate the pressure of the aqueous solution delivered to the reactant fuel material in the reactor based upon characteristics of the pressurization mechanisms and can regulate the pressure of the delivered aqueous solution as a steady decay associated with the pressurization force. The pressure regulation mechanism can also prevent hydrogen gas from deflecting the pressure regulation mechanism.

  4. International Conference on Solar Concentrators for the Generation of Electricity or Hydrogen: Book of Abstracts

    Energy Technology Data Exchange (ETDEWEB)

    McConnell, R.; Symko-Davies, M.; Hayden, H.

    2005-05-01

    The International Conference on Solar Concentrators for the Generation of Electricity or Hydrogen provides an opportunity to learn about current significant research on solar concentrators for generating electricity or hydrogen. The conference will emphasize in-depth technical discussions of recent achievements in technologies that convert concentrated solar radiation to electricity or hydrogen, with primary emphasis on photovoltaic (PV) technologies. Very high-efficiency solar cells--above 37%--were recently developed, and are now widely used for powering satellites. This development demands that we take a fresh look at the potential of solar concentrators for generating low-cost electricity or hydrogen. Solar electric concentrators could dramatically overtake other PV technologies in the electric utility marketplace because of the low capital cost of concentrator manufacturing facilities and the larger module size of concentrators. Concentrating solar energy also has advantages for th e solar generation of hydrogen. Around the world, researchers and engineers are developing solar concentrator technologies for entry into the electricity generation market and several have explored the use of concentrators for hydrogen production. The last conference on the subject of solar electric concentrators was held in November of 2003 and proved to be an important opportunity for researchers and developers to share new and crucial information that is helping to stimulate projects in their countries.

  5. Thermo-economic analysis of integrated membrane-SMR ITM-oxy-combustion hydrogen and power production plant

    International Nuclear Information System (INIS)

    Sanusi, Yinka S.; Mokheimer, Esmail M.A.; Habib, Mohamed A.

    2017-01-01

    Highlights: •A methane reforming reactor integrated to an oxy-combustion plant is proposed. •Co-production of power and hydrogen was investigated and presented. •Optimal thermo-economic operating conditions of the system were identified and presented. •The ion transport membrane oxygen separation unit has the highest capital cost. •The combustor has the highest exergy destruction. -- Abstract: The demand for hydrogen has greatly increased in the last decade due to the stringent regulations enacted to address environmental pollution concerns. Natural gas reforming is currently the most mature technology for large-scale hydrogen production. However, it is usually associated with greenhouse gas emissions. As part of the strategies to reduce greenhouse gas emissions, new designs need to be developed to integrate hydrogen production facilities that are based on natural gas reforming with carbon capture facilities. In this study, we carried out energy, exergy and economic analysis of hydrogen production in a steam methane reforming reactor integrated with an oxy-combustion plant for co-production of power and hydrogen. The results show that the overall system efficiency and hydrogen production efficiency monotonically increase with increasing the combustor exit temperature (CET), increasing the amount of hydrogen extracted and decreasing the auxiliary fuel added to the system. The optimal thermo-economic operating conditions of the system were obtained as reformer pressure of 15 bar, auxiliary fuel factor of 0.8 and hydrogen extraction factor of 0.6. The production cost of hydrogen using the proposed system, under these optimal operating conditions, is within the range suggested by the International Energy Agency (IEA). Further analysis shows that the capital cost of the membrane-air separation unit (ITM) has the major share in the total investment cost of the system and constitutes 37% of the total capital cost of the system at the CET of 1500 K. The exergy

  6. A rationale for large inertial fusion plants producing hydrogen for powering low emission vehicles

    International Nuclear Information System (INIS)

    Logan, B.G.

    1993-01-01

    Inertial Fusion Energy (IFE) has been identified in the 1991 National Energy Strategy, along with Magnetic Fusion Energy (MFE), as one of only three inexhaustible energy sources for long term energy supply (past 2025), the other alternatives being fission and solar energy. Fusion plants, using electrolysis, could also produce hydrogen to power low emission vehicles in a potentially huge future US market: > 500 GWe would be needed for example, to replace all foreign oil imports with equal-energy hydrogen, assuming 70%-efficient electrolysis. Any inexhaustible source of electricity, including IFE and MFE reactors, can thus provide a long term renewable source of hydrogen as well as solar, wind and biomass sources. Hydrogen production by both high temperature thermochemical cycles and by electrolysis has been studied for MFE, but avoiding trace tritium contamination of the hydrogen product would best be assured using electrolysis cells well separated from any fusion coolant loops. The motivations to consider IFE or MFE producing renewable hydrogen are: (1) reducing US dependence on foreign oil imports and the associated trade deficient; (2) a hydrogen-based transportation system could greatly mitigate future air pollution and greenhouse gases; (3) investments in hydrogen pipelines, storage, and distribution systems could be used for a variety of hydrogen sources; (4) a hydrogen pipeline system could access and buffer sufficiently large markets that temporary outages of large (>> 1 GWe size) fusion hydrogen units could be tolerated

  7. Zircaloy-oxidation and hydrogen-generation rates in degraded-core accident situations

    International Nuclear Information System (INIS)

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

    1983-02-01

    Oxidation of Zircaloy cladding is the primary source of hydrogen generated during a degraded-core accident. In this paper, reported Zircaloy oxidation rates, either measured at 1500 to 1850 0 C or extrapolated from the low-temperature data obtained at 0 C, are critically reviewed with respect to their applicability to a degraded-core accident situation in which the high-temperature fuel cladding is likely to be exposed to and oxidized in mixtures of hydrogen and depleted steam, rather than in an unlimited flux of pure steam. New results of Zircaloy oxidation measurements in various mixtures of hydrogen and steam are reported for >1500 0 C. The results show significantly smaller oxidation and, hence, hydrogen-generation rates in the mixture, compared with those obtained in pure steam. It is also shown that a significant fraction of hydrogen, generated as a result of Zircaloy oxidation, is dissolved in the cladding material itself, which prevents that portion of hydrogen from reaching the containment building space. Implications of these findings are discussed in relation to a more realistic method of quantifying the hydrogen source term for a degraded-core accident analysis

  8. The PBMR electric power generation plant

    International Nuclear Information System (INIS)

    Perez S, G.; Santacruz I, I.; Martin del Campo M, C.

    2003-01-01

    This work has as purpose to diffuse in a general way the technology of the one modulate reactor of pebble bed. Because our country is in developing ways, the electric power demand goes in increase with that which it is presented the great challenge of satisfying this necessity, not only being in charge of the one fact per se, but also involving the environmental aspect and of security. Both factors are covered by the PBMR technology, which we approach in their basic aspects with the purpose that the public opinion knows it and was familiarized with this type of reactors that well could represent a solution for our growing electricity demand. We will treat this reactor visualizing it like part of a generation plant defining in first place to the itself reactor. We will see because that the system PBMR consists of 2 main sections: the reactor and the unit of energy conversion, highlighting that the principle of the PBMR reactor operation is based on the thermodynamic Brayton cycle cooled by helium and that, in turn, it transmits the energy in form of heat toward a gas turbine. In what concerns to the fuel, it peculiar design due to its spherical geometry is described, aspect that make to this reactor different from the traditional ones that use fuel rods. In fact in the fuel spheres of the PBMR it is where it resides great part of it inherent security since each particle of fuel, consistent in uranium dioxide, is lined one with coal and silicon carbide those which form an impenetrable barrier containing to the fuel and those radioactive products that result of the nuclear reactions. Such particles are encapsulated in graphite to form the sphere or 'pebble', of here born the name of this innovative technology. (Author)

  9. Generating hydrogen from sunlight and water using photovoltaic tandem cell

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2006-07-15

    Photoelectrochemical conversion of solar energy to energy in hydrogen at viable efficiency is a long-term goal needed to usher in the hydrogen economy worldwide. The twin cell technology based Tandem Cell tackles a number of challenges faced by single photoelectrochemical cell based water splitting and offers a novel way of utilising complimentary parts of the solar spectrum in two cells. The overall process results in a complete system driven by solar energy that splits water into hydrogen and oxygen. Hydrogen Solar Ltd is a UK based enterprise that is working towards commercialisation of this Tandem Cell technology. One of the main project activities involved the development and optimisation of methods for preparation of larger scale photocatalytic electrodes using reproducible low cost industrial processes, with efficiencies equal to or greater than those from small scale samples made experimentally in University laboratories. Stability is also an important issue and endurance testing was performed on some samples. Spray pyrolysis methods offer considerable promise as for preparation of metal oxide semiconductor films at low cost, reproducibly. These studies lead to optimised designs for Tandem Cells, resulting in construction of an array of 12 Tandem Cells. The findings of this array work, in particular engineering issues, were very significant. Based on this work it is intended to build another two array systems that consists of 24 Tandem Cells which will be tested for light to chemical conversion efficiency, to determine what efficiency has been achieved overall. The main conclusions resulting from this project were as follows. Overall, considerable progress was made in characterising the factors that affect photoelectrode performance efficiency but that, losses in efficiency when increasing the area of photoelectrodes was greater than expected and optimisation of efficiency at practical device scale needs more work. Based on the outcome of this work program

  10. Defects generation by hydrogen passivation of polycrystalline silicon thin films

    Czech Academy of Sciences Publication Activity Database

    Honda, Shinya; Mates, Tomáš; Ledinský, Martin; Fejfar, Antonín; Kočka, Jan; Yamazaki, T.; Uraoka, Y.; Fuyuki, T.; Boldyryeva, Hanna; Macková, Anna; Peřina, Vratislav

    2006-01-01

    Roč. 80, - (2006), s. 653-657 ISSN 0038-092X R&D Projects: GA MŽP(CZ) SM/300/1/03; GA MŽP(CZ) SN/3/172/05; GA AV ČR IAA1010413; GA ČR(CZ) GD202/05/H003; GA AV ČR IAA1010316 Institutional research plan: CEZ:AV0Z10100521; CEZ:AV0Z10480505 Keywords : hydrogen passivation * ERDA * photoluminescence * Raman spectroscopy * Si-H 2 bonding * H 2 molecules * grain size. Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.431, year: 2006

  11. Hydrogen Safety Analysis of the OPR1000 Nuclear Power Plant during a Severe Accident by a Small-Break Loss of Coolant

    International Nuclear Information System (INIS)

    Kim, Jong Tae; Park, Soo Yong; Ha, Kwang Soon; Hong, Seong Wan; Kim, Sang Baik

    2009-01-01

    A huge amount of hydrogen can be generated in a nuclear reactor and released into the reactor containment if a hypothetical severe accident happens. Even for the accident, the hydrogen concentrations must be safely controlled. In order to prove a nuclear power plant (NPP) safe from hydrogen, a simulation of hydrogen distributions in the containment are usually conducted by using a 1-dimensional thermo-hydraulic system code. If there exists a possibility of a hydrogen explosion in the containment, it is required to install a hydrogen mitigation system such as igniters or hydrogen recombiner. For a licensing of NPP construction and operation, the hydrogen combustion and hydrogen mitigation system in the containment is one of the important safety issues. In Korea, two OPR1000 NPPs by the name of Shin-Wolsung 1 and 2 are under construction. The hydrogen safety and its control for the new NPPs will be evaluated in detail until a licensing of the operation. Until now, simulations of the hydrogen behaviors in the OPR1000 have been conducted by a lumped method for each compartment in the containment using CONTAIN or MAAP. This 1-dimensional method is very efficient for a long-term simulation of an accident because of its fast running time, and it is very effective for establishing the averaged hydrogen concentrations in each compartment. But a 3-dimensional flow structure developed by a discharged mass from a reactor vessel and local concentrations of hydrogen are difficult to be resolved by the lumped method. In this study, hydrogen distributions and characteristics of hydrogen mixture cloud such as a possibility of flame acceleration in each compartment of OPR1000 containment were evaluated by using GASFLOW code

  12. Control of microbially generated hydrogen sulfide in produced waters

    Energy Technology Data Exchange (ETDEWEB)

    Burger, E.D.; Vance, I.; Gammack, G.F.; Duncan, S.E.

    1995-12-31

    Production of hydrogen sulfide in produced waters due to the activity of sulfate-reducing bacteria (SRB) is a potentially serious problem. The hydrogen sulfide is not only a safety and environmental concern, it also contributes to corrosion, solids formation, a reduction in produced oil and gas values, and limitations on water discharge. Waters produced from seawater-flooded reservoirs typically contain all of the nutrients required to support SRB metabolism. Surface processing facilities provide a favorable environment in which SRB flourish, converting water-borne nutrients into biomass and H{sub 2}S. This paper will present results from a field trial in which a new technology for the biochemical control of SRB metabolism was successfully applied. A slip stream of water downstream of separators on a produced water handling facility was routed through a bioreactor in a side-steam device where microbial growth was allowed to develop fully. This slip stream was then treated with slug doses of two forms of a proprietary, nonbiocidal metabolic modifier. Results indicated that H{sub 2}S production was halted almost immediately and that the residual effect of the treatment lasted for well over one week.

  13. Cost Evaluation with G4-ECONS Program for SI based Nuclear Hydrogen Production Plant

    International Nuclear Information System (INIS)

    Kim, Jong-ho; Lee, Ki-young; Kim, Yong-wan

    2014-01-01

    Contemporary hydrogen is production is primarily based on fossil fuels, which is not considered as environments friendly and economically efficient. To achieve the hydrogen economy, it is very important to produce a massive amount of hydrogen in a clean, safe and efficient way. Nuclear production of hydrogen would allow massive production of hydrogen at economic prices while avoiding environments pollution reducing the release of carbon dioxide. Nuclear production of hydrogen could thus become the enabling technology for the hydrogen economy. The economic assessment was performed for nuclear hydrogen production plant consisting of VHTR coupled with SI cycle. For the study, G4-ECONS developed by EMWG of GIF was appropriately modified to calculate the LUHC, assuming 36 months of plant construction time, 5 % of annual interest rate and 12.6 % of fixed charge rate. In G4-ECONS program, LUHC is calculated by the following formula; LUHC = (Annualized TCIC + Annualized O-M Cost + Annualized Fuel Cycle Cost + Annualized D-D Cost) / Annual Hydrogen Production Rate

  14. Hydrogen generation by nuclear power for sustainable development in the 21-st century

    International Nuclear Information System (INIS)

    Bilegan, Iosif Constantin; Pall, Stefan

    2002-01-01

    Hydrogen is the main non-polluting fuel. It is produced by natural gas steam reforming, water electrolysis and thermonuclear processes. Currently, 4% of the hydrogen world production is obtained by water electrolysis. The use of nuclear power for hydrogen production avoids the generation of greenhouse gases and the dependence of primary external energy sources. The US is currently developing a modular reactor for hydrogen production and water desalination, STAR - H 2 (Secure Transportable Autonomous Reactor for Hydrogen production) with fast neutrons, lead cooling and passive safety systems operating at a temperature of 780 deg C. Also, a Russian reactor of the same type is operated at 540 deg C. China and India joint industrial countries like France, Japan, Russia and US in recognizing that any strategies aiming at a future with clean energy implies the nuclear energy

  15. Second generation plant health clinics in Uganda

    DEFF Research Database (Denmark)

    Danielsen, Solveig; Matsiko, Frank; Mutebi, Emmanuel

    coverage, Regularity/timeliness and Quality of plant healthcare. Field work was carried out over 15 months between July 2010 and September 2011 in 13 districts in the eastern, central and western parts of Uganda. A total of 205 plant clinic sessions were held in the period. The plant clinics received 2...... from the clinics to diagnostic laboratories. Although the plant clinics have become part of Ministry policy and districts showed increasing interest and commitment, there are some structural barriers that made it difficult for the districts to institutionalise the clinics and for the Ministry to play...... their leading role. A mismatch between institutional mandates/authority and allocated resources limited the scope of the actions both at district and national level. The plant clinics risk ‘falling between the two chairs’ of extension and pest and disease control. Finding a solid institutional base...

  16. A Systems Engineering Framework for Design, Construction and Operation of the Next Generation Nuclear Plant

    International Nuclear Information System (INIS)

    Edward J. Gorski; Charles V. Park; Finis H. Southworth

    2004-01-01

    Not since the International Space Station has a project of such wide participation been proposed for the United States. Ten countries, the European Union, universities, Department of Energy (DOE) laboratories, and industry will participate in the research and development, design, construction and/or operation of the fourth generation of nuclear power plants with a demonstration reactor to be built at a DOE site and operational by the middle of the next decade. This reactor will be like no other. The Next Generation Nuclear Plant (NGNP) will be passively safe, economical, highly efficient, modular, proliferation resistant, and sustainable. In addition to electrical generation, the NGNP will demonstrate efficient and cost effective generation of hydrogen to support the President's Hydrogen Initiative. To effectively manage this multi-organizational and technologically complex project, systems engineering techniques and processes will be used extensively to ensure delivery of the final product. The technological and organizational challenges are complex. Research and development activities are required, material standards require development, hydrogen production, storage and infrastructure requirements are not well developed, and the Nuclear Regulatory Commission may further define risk-informed/performance-based approach to licensing. Detailed design and development will be challenged by the vast cultural and institutional differences across the participants. Systems engineering processes must bring the technological and organizational complexity together to ensure successful product delivery. This paper will define the framework for application of systems engineering to this $1.5B - $1.9B project

  17. Conversion of Claus plants of Kirkuk-Iraq to produce hydrogen and sulfur

    International Nuclear Information System (INIS)

    Naman, S.A.; Veziroglu, A.

    2009-01-01

    'Full text': Hydrogen production from rich sub-quality natural gas (SQNG) is visible technically with assessment of cost, safety and environmental toxicology analysis of hydrogen sulfide, is summarized. There are two Claus plants in Kirkuk-Iraq, converting hydrogen sulfide to elemental sulfur capacity of 2200 ton/day. One of these plants is working with only 400 ton/day and it is an old Claus process. The other is a modified Claus sulfur recovery process with a capacity of 1800 ton/day. Both of these plants operate with low efficiency due to lack of maintenance and the present situation in Iraq. Therefore, the agricultural area around Kirkuk is very polluted by this gas. Two pilot plants have been constructed inside the modified Claus plant in Kirkuk The first one is based on the flow system tube furnace reactor containing mixed Titanium oxide/sulfide with a cold trap for sulfur separation and a bath of 30% dithanolamine to separate and recycle H 2 S from hydrogen. The second pilot plant consists of a thermal diffusion ceramic rod inside a silica column containing Zeolit 5A as a catalyst. This pilot plant also consists of a trap for continuous separation of sulfur and a system for separation of hydrogen from unreacted H 2 S to recycle. The efficiency of conversion of H 2 S to hydrogen and sulfur has been optimized as a function of catalyst type and mixture, temperature of furnace, flow rate of gas and reactor materials until the efficiency reaches more than 97%. The Kirkuk natural gas consists of a mixture of CO 2 10% and H 2 S 12%. We found that these pilot plants were suitable with Cadmium chalcogens catalysts to produce hydrogen, methane, ethane and sulphur, but with lower efficiency than H 2 S decomposition only. Our aim in the second pilot plant, which consists of a silica column, was to supply the heat by solar energy concentrator instead of electricity as our catalyst needs 450 o C. and the solar intensity is about 1000 w/m 2 during the summer. The idea of

  18. InP nanopore arrays for photoelectrochemical hydrogen generation.

    Science.gov (United States)

    Li, Qiang; Zheng, Maojun; Zhang, Bin; Zhu, Changqing; Wang, Faze; Song, Jingnan; Zhong, Miao; Ma, Li; Shen, Wenzhong

    2016-02-19

    We report a facile and large-scale fabrication of highly ordered one-dimensional (1D) indium phosphide (InP) nanopore arrays (NPs) and their application as photoelectrodes for photoelectrochemical (PEC) hydrogen production. These InP NPs exhibit superior PEC performance due to their excellent light-trapping characteristics, high-quality 1D conducting channels and large surface areas. The photocurrent density of optimized InP NPs is 8.9 times higher than that of planar counterpart at an applied potential of +0.3 V versus RHE under AM 1.5G illumination (100 mW cm(-2)). In addition, the onset potential of InP NPs exhibits 105 mV of cathodic shift relative to planar control. The superior performance of the nanoporous samples is further explained by Mott-Schottky and electrochemical impedance spectroscopy ananlysis.

  19. Empirical rate equation model and rate calculations of hydrogen generation for Hanford tank waste

    International Nuclear Information System (INIS)

    HU, T.A.

    1999-01-01

    Empirical rate equations are derived to estimate hydrogen generation based on chemical reactions, radiolysis of water and organic compounds, and corrosion processes. A comparison of the generation rates observed in the field with the rates calculated for twenty eight tanks shows agreement within a factor of two to three

  20. Characterization plan for the Hanford Generating Plant (HGP)

    International Nuclear Information System (INIS)

    Marske, S.G.

    1996-09-01

    This characterization plan describes the sample collection and sample analysis activities to characterize the Hanford Generating Plant and associated solid waste management units (SWMUs). The analytical data will be used to identify the radiological contamination in the Hanford Generating Plant as well as the presence of radiological and hazardous materials in the SWMUs to support further estimates of decontamination interpretation for demolition

  1. Hydrogen Fuel Cell Analysis: Lessons Learned from Stationary Power Generation Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Scott E. Grasman; John W. Sheffield; Fatih Dogan; Sunggyu Lee; Umit O. Koylu; Angie Rolufs

    2010-04-30

    This study considered opportunities for hydrogen in stationary applications in order to make recommendations related to RD&D strategies that incorporate lessons learned and best practices from relevant national and international stationary power efforts, as well as cost and environmental modeling of pathways. The study analyzed the different strategies utilized in power generation systems and identified the different challenges and opportunities for producing and using hydrogen as an energy carrier. Specific objectives included both a synopsis/critical analysis of lessons learned from previous stationary power programs and recommendations for a strategy for hydrogen infrastructure deployment. This strategy incorporates all hydrogen pathways and a combination of distributed power generating stations, and provides an overview of stationary power markets, benefits of hydrogen-based stationary power systems, and competitive and technological challenges. The motivation for this project was to identify the lessons learned from prior stationary power programs, including the most significant obstacles, how these obstacles have been approached, outcomes of the programs, and how this information can be used by the Hydrogen, Fuel Cells & Infrastructure Technologies Program to meet program objectives primarily related to hydrogen pathway technologies (production, storage, and delivery) and implementation of fuel cell technologies for distributed stationary power. In addition, the lessons learned address environmental and safety concerns, including codes and standards, and education of key stakeholders.

  2. Hydrogen Peroxide- and Nitric Oxide-mediated Disease Control of Bacterial Wilt in Tomato Plants

    Directory of Open Access Journals (Sweden)

    Jeum Kyu Hong

    2013-12-01

    Full Text Available Reactive oxygen species (ROS generation in tomato plants by Ralstonia solanacearum infection and the role of hydrogen peroxide (H₂O₂ and nitric oxide in tomato bacterial wilt control were demonstrated. During disease development of tomato bacterial wilt, accumulation of superoxide anion (O₂− and H₂O₂ was observed and lipid peroxidation also occurred in the tomato leaf tissues. High doses of H₂O₂and sodium nitroprusside (SNP nitric oxide donor showed phytotoxicity to detached tomato leaves 1 day after petiole feeding showing reduced fresh weight. Both H₂O₂and SNP have in vitro antibacterial activities against R. solanacearum in a dose-dependent manner, as well as plant protection in detached tomato leaves against bacterial wilt by 10⁶ and 10⁷ cfu/ml of R. solanacearum. H₂O₂- and SNP-mediated protection was also evaluated in pots using soil-drench treatment with the bacterial inoculation, and relative ‘area under the disease progressive curve (AUDPC’ was calculated to compare disease protection by H₂O₂ and/or SNP with untreated control. Neither H₂O₂ nor SNP protect the tomato seedlings from the bacterial wilt, but H₂O₂+ SNP mixture significantly decreased disease severity with reduced relative AUDPC. These results suggest that H₂O₂ and SNP could be used together to control bacterial wilt in tomato plants as bactericidal agents.

  3. Next Generation Nuclear Plant Intermediate Heat Exchanger Acquisition Strategy

    Energy Technology Data Exchange (ETDEWEB)

    Mizia, Ronald Eugene [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2008-04-01

    DOE has selected the High Temperature Gas-cooled Reactor (HTGR) design for the Next Generation Nuclear Plant (NGNP) Project. The NGNP will demonstrate the use of nuclear power for electricity and hydrogen production. It will have an outlet gas temperature in the range of 900°C to 950°C and a plant design service life of 60 years. The reactor design will be a graphite moderated, helium cooled, prismatic or pebble-bed reactor, and use low-enriched uranium, TRISO-coated fuel. The plant size, reactor thermal power, and core configuration will ensure passive decay heat removal without fuel damage or radioactive material releases during accidents. The NGNP Materials Research and Development (R&D) Program is responsible for performing R&D on likely NGNP materials in support of the NGNP design, licensing, and construction activities. Selection of the technology and design configuration for the NGNP must consider both the cost and risk profiles to ensure that the demonstration plant establishes a sound foundation for future commercial deployments. The NGNP challenge is to achieve a significant advancement in nuclear technology while at the same time setting the stage for an economically viable deployment of the new technology in the commercial sector soon after 2020. The purpose of this report is to address the acquisition strategy for the NGNP Intermediate Heat Exchanger (IHX).This component will be operated in flowing, impure helium on the primary and secondary side at temperatures up to 950°C. There are major high temperature design, materials availability, and fabrication issues that need to be addressed. The prospective materials are Alloys 617, 230, 800H and X, with Alloy 617 being the leading candidate for the use at 950°C. The material delivery schedule for these materials does not pose a problem for a 2018 start up as the vendors can quote reasonable delivery times at the moment. The product forms and amount needed must be finalized as soon as possible. An

  4. Design and Control of Integrated Systems for Hydrogen Production and Power Generation

    Science.gov (United States)

    Georgis, Dimitrios

    Growing concerns on CO2 emissions have led to the development of highly efficient power plants. Options for increased energy efficiencies include alternative energy conversion pathways, energy integration and process intensification. Solid oxide fuel cells (SOFC) constitute a promising alternative for power generation since they convert the chemical energy electrochemically directly to electricity. Their high operating temperature shows potential for energy integration with energy intensive units (e.g. steam reforming reactors). Although energy integration is an essential tool for increased efficiencies, it leads to highly complex process schemes with rich dynamic behavior, which are challenging to control. Furthermore, the use of process intensification for increased energy efficiency imposes an additional control challenge. This dissertation identifies and proposes solutions on design, operational and control challenges of integrated systems for hydrogen production and power generation. Initially, a study on energy integrated SOFC systems is presented. Design alternatives are identified, control strategies are proposed for each alternative and their validity is evaluated under different operational scenarios. The operational range of the proposed control strategies is also analyzed. Next, thermal management of water gas shift membrane reactors, which are a typical application of process intensification, is considered. Design and operational objectives are identified and a control strategy is proposed employing advanced control algorithms. The performance of the proposed control strategy is evaluated and compared with classical control strategies. Finally SOFC systems for combined heat and power applications are considered. Multiple recycle loops are placed to increase design flexibility. Different operational objectives are identified and a nonlinear optimization problem is formulated. Optimal designs are obtained and their features are discussed and compared

  5. Fast Breaking Detergents: Their Role in the Generation of Hydrogen Sulfide in Oily-Water Wastes

    Science.gov (United States)

    1993-09-01

    acid (Dwyer & Tiedje, 1983) and Desulfowibrio desulfitricans to produce ethanol and acetic acid (Dwyer & Tiedje, 1986). Under anaerobic conditions, the...glycol, glycolic acid, hydrogen, carbon dioxide and a number of intermediates. The acetic acid and ethylene glycol are utilised by some species of SRB...are consequently being introduced. Hydrogen sulfide generation by anaerobic sulfate-reducing bacteria (SRB) is a concern for the RAN because it can

  6. Identification of intrinsic catalytic activity for electrochemical reduction of water molecules to generate hydrogen

    KAUST Repository

    Shinagawa, Tatsuya

    2015-01-01

    Insufficient hydronium ion activities at near-neutral pH and under unbuffered conditions induce diffusion-limited currents for hydrogen evolution, followed by a reaction with water molecules to generate hydrogen at elevated potentials. The observed constant current behaviors at near neutral pH reflect the intrinsic electrocatalytic reactivity of the metal electrodes for water reduction. This journal is © the Owner Societies.

  7. Effects of hydrogen fluoride fumigation of bean plants on the growth, development, and reproduction of the Mexican bean beetle

    Energy Technology Data Exchange (ETDEWEB)

    Weinstein, L H; McCune, D C; Mancini, J F; van Leuken, P

    1973-01-01

    The growth and behavior of Mexican bean beetle populations on control and hydrogen fluoride-fumigated bean plants (P. vulgaris L.) were investigated to assess the effects of such fumigation on beetle growth, development and reproduction. Beetles that were cultured on HF-fumigated plants were generally lighter than controls, although the occurrence and magnitude of this effect depended upon stage of development, age, and sex of the adult beetle and the number of generations of culture on HF-fumigated plants. A consistently decreased mass of larvae cultured on HF-fumigated tissue pupated and enclosed three to six days later than controls, and the adults commenced reproductive activity with the same lag in time. Beetles cultured on the fumigated plants also contained greater amounts of fluoride than the controls, and the fluoride content of females was greater than that of males on both HF-fumigated and control plants. Beetles raised on fumigated plants laid fewer egg masses and fewer eggs per mass, although when the first generation was repeated at a later date there was no significant effect. Feeding activity was reduced in both larval and adult stages in beetles cultured on the fumigated plants, and adults showed less flight activity than controls. A difference in color of the elytra was also noted; beetles on HF-fumigated plants were paler than controls.

  8. Thermodynamic analysis of SCW NPP cycles with thermo-chemical co-generation of hydrogen

    International Nuclear Information System (INIS)

    Naidin, N.; Mokry, S.; Monichan, R.; Chophla, K.; Pioro, I.; Naterer, G.; Gabriel, K.

    2009-01-01

    Research activities are currently conducted worldwide to develop Generation IV nuclear reactor concepts with the objective of improving thermal efficiency and increasing economic competitiveness of Generation IV Nuclear Power Plants (NPPs) compared to modern thermal power plants. The Super-Critical Water-cooled Reactor (SCWR) concept is one of the six Generation IV options chosen for further investigation and development in several countries including Canada and Russia. Water-cooled reactors operating at subcritical pressures (10 - 16 MPa) have provided a significant amount of electricity production for the past 50 years. However, the thermal efficiency of the current NPPs is not very high (30 - 35%). As such, more competitive designs, with higher thermal efficiencies, which will be close to that of modern thermal power plants (45 - 50%), need to be developed and implemented. Super-Critical Water (SCW) NPPs will have much higher operating parameters compared to current NPPs (i.e., steam pressures of about 25 MPa and steam outlet temperatures up to 625 o C). Furthermore, SCWRs operating at higher temperatures can facilitate an economical co-generation of hydrogen through thermochemical cycles (particularly, the copper-chlorine cycle) or direct high-temperature electrolysis. The two SCW NPP cycles proposed by this paper are based on direct, regenerative, no-reheat and single-reheat configurations. As such, the main parameters and performance in terms of thermal efficiency of the SCW NPP concepts mentioned above are being analyzed. The cycles are generally comprised of: an SCWR, a SC turbine, one deaerator, ten feedwater heaters, and pumps. The SC turbine of the no-reheat cycle consists of one High-Pressure (HP) cylinder and two Low-Pressure (LP) cylinders. Alternatively, the SC turbine for the single-reheat cycle is comprised of one High-Pressure (HP) cylinder, one Intermediate-Pressure (IP) cylinder and two Low-Pressure (LP) cylinders. Since the single-reheat option

  9. Electroless Nickel-Based Catalyst for Diffusion Limited Hydrogen Generation through Hydrolysis of Borohydride

    Directory of Open Access Journals (Sweden)

    Shannon P. Anderson

    2013-07-01

    Full Text Available Catalysts based on electroless nickel and bi-metallic nickel-molybdenum nanoparticles were synthesized for the hydrolysis of sodium borohydride for hydrogen generation. The catalysts were synthesized by polymer-stabilized Pd nanoparticle-catalyzation and activation of Al2O3 substrate and electroless Ni or Ni-Mo plating of the substrate for selected time lengths. Catalytic activity of the synthesized catalysts was tested for the hydrolyzation of alkaline-stabilized NaBH4 solution for hydrogen generation. The effects of electroless plating time lengths, temperature and NaBH4 concentration on hydrogen generation rates were analyzed and discussed. Compositional analysis and surface morphology were carried out for nano-metallized Al2O3 using Scanning Electron Micrographs (SEM and Energy Dispersive X-Ray Microanalysis (EDAX. The as-plated polymer-stabilized electroless nickel catalyst plated for 10 min and unstirred in the hydrolysis reaction exhibited appreciable catalytic activity for hydrolysis of NaBH4. For a zero-order reaction assumption, activation energy of hydrogen generation using the catalyst was estimated at 104.6 kJ/mol. Suggestions are provided for further work needed prior to using the catalyst for portable hydrogen generation from aqueous alkaline-stabilized NaBH4 solution for fuel cells.

  10. Production of Plant Phthalate and its Hydrogenated Derivative from Bio-Based Platform Chemicals.

    Science.gov (United States)

    Lu, Rui; Lu, Fang; Si, Xiaoqin; Jiang, Huifang; Huang, Qianqian; Yu, Weiqiang; Kong, Xiangtao; Xu, Jie

    2018-04-06

    Direct transformation of bio-based platform chemicals into aromatic dicarboxylic acids and their derivatives, which are widely used for the manufacture of polymers, is of significant importance for the sustainable development of the plastics industry. However, limited successful chemical processes have been reported. This study concerns a sustainable route for the production of phthalate and its hydrogenated derivative from bio-based malic acid and erythritol. The key Diels-Alder reaction is applied to build a substituted cyclohexene structure. The dehydration reaction of malic acid affords fumaric acid with 96.6 % yield, which could be used as the dienophile, and 1,3-butadiene generated in situ through erythritol deoxydehydration serves as the diene. Starting from erythritol and dibutyl fumarate, a 74.3 % yield of dibutyl trans-4-cyclohexene-1,2-dicarboxylate is obtained. The palladium-catalyzed dehydrogenation of the cycloadduct gives a 77.8 % yield of dibutyl phthalate. Dibutyl trans-cyclohexane-1,2-dicarboxylate could be formed in nearly 100 % yield under mild conditions by hydrogenation of the cycloadduct. Furthermore, fumaric acid and fumarate, with trans configurations, were found to be better dienophiles for this Diels-Alder reaction than maleic acid and maleate, with cis configuration, based on the experimental and computational results. This new route will pave the way for the production of environmental friendly plastic materials from plants. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Hydrogen generation behaviors of NaBH4-NH3BH3 composite by hydrolysis

    Science.gov (United States)

    Xu, Yanmin; Wu, Chaoling; Chen, Yungui; Huang, Zhifen; Luo, Linshan; Wu, Haiwen; Liu, Peipei

    2014-09-01

    In this work, NH3BH3 (AB) is used to induce hydrogen generation during NaBH4 (SB) hydrolysis in order to reduce the use of catalysts, simplify the preparation process, reduce the cost and improve desorption kinetics and hydrogen capacity as well. xNaBH4-yNH3BH3 composites are prepared by ball-milling in different proportions (from x:y = 1:1 to 8:1). The experimental results demonstrate that all composites can release more than 90% of hydrogen at 70 °C within 1 h, and their hydrogen yields can reach 9 wt% (taking reacted water into account). Among them, the composites in the proportion of 4:1 and 5:1, whose hydrogen yields reach no less than 10 wt%, show the best hydrogen generation properties. This is due to the impact of the following aspects: AB additive improves the dispersibility of SB particles, makes the composite more porous, hampers the generated metaborate from adhering to the surface of SB, and decreases the pH value of the composite during hydrolysis. The main solid byproduct of this hydrolysis system is NaBO2·2H2O. By hydrolytic kinetic simulation of the composites, the fitted activation energies of the complexes are between 37.2 and 45.6 kJ mol-1, which are comparable to the catalytic system with some precious metals and alloys.

  12. Development of valuation method for location planning and dimensioning of hydrogen plants

    International Nuclear Information System (INIS)

    Guenther, Thomas

    2014-01-01

    Common decisions for locations of production plants are based on criteria such as availability of commodities, energy, infrastructure and costs related with these. Sizing of product capacities depends on other things such as production quantities to be sold and profits to be obtained. The condition is an permanent availability of the required energy. For concepts of using surplus renewable energies especially wind energy for hydrogen production common methods are only partly suitable. Thus in this work an evaluation methodology was developed which integrated duration and amount of available energy for decisions of locations and dimensioning of the plant. Initially the hydrogen plant is modularised and segmented to the sub processed energy supply, water supply, water electrolyses, cooling, storing and compression for transport. After the specification of technological and economical parameters, the material and energy streams as well as the costs are calculated for every individual plant. Based on the given conditions, the configuration of plant and also the investigation of site-specific production costs is done. By variation of technology and costs parameters, feasibility studies and different operating scenarios can be demonstrated. The application of this evaluation methodology is demonstrated by case studies. A hydrogen plant situated at an industry park serves as a reference plant for the continuous operation with grid energy. Using a wind energy propelled hydrogen plant as an example, the effects of amount and duration of the usable energy are shown. Based on predefined hydrogen prices, the correlation between optimal plant capacity and plant utilization is described and the difference between the predefined price and the operation costs is calculated. This difference can be used to finance the wind farm operation. The results serves among others for the development of optimal operation concepts and also for first cost estimations, prior to a detailed plant

  13. Generator technology for HTGR power plants

    International Nuclear Information System (INIS)

    Lomba, D.; Thiot, D.

    1997-01-01

    Approximately 15% of the worlds installed capacity in electric energy production is from generators developed and manufactured by GEC Alsthom. GEC Alsthom is now working on the application of generators for HTGR power conversion systems. The main generator characteristics induced by the different HTGR power conversion technology include helium immersion, high helium pressure, brushless excitation system, magnetic bearings, vertical lineshaft, high reliability and long periods between maintenance. (author)

  14. Nuclear power plant equipped with hydrogen removing system

    International Nuclear Information System (INIS)

    Ezawa, Shin-ichi; Yamanari, Shozo; Okura, Minoru; Kamizuma, Nobuaki.

    1998-01-01

    A γ-shield and container spray pipelines are disposed to an upper dry well in a reactor container incorporating a reactor pressure vessel. A plurality of catalytic hydrogen removing devices are disposed close to a wall on the side of the pressure vessel in the dry well and a wall on the side of the outer wall of the reactor container. The plurality of catalytic hydrogen removing devices are disposed substantially equally in horizontal direction and circumferential direction of the side walls. If container spray water is sprayed, the atmospheric gases in the reactor are compulsory circulated. In addition, since the temperature of the γ-shield is higher than the atmospheric temperature, spontaneous circulation is caused. As a result, rising currents of gases are formed at regions in the vicinity of the γ-shield. The catalytic hydrogen removing devices are disposed to the places where the rising currents are formed. (I.N.)

  15. High Performance, Low Cost Hydrogen Generation from Renewable Energy

    Energy Technology Data Exchange (ETDEWEB)

    Ayers, Katherine [Proton OnSite; Dalton, Luke [Proton OnSite; Roemer, Andy [Proton OnSite; Carter, Blake [Proton OnSite; Niedzwiecki, Mike [Proton OnSite; Manco, Judith [Proton OnSite; Anderson, Everett [Proton OnSite; Capuano, Chris [Proton OnSite; Wang, Chao-Yang [Penn State University; Zhao, Wei [Penn State University

    2014-02-05

    Renewable hydrogen from proton exchange membrane (PEM) electrolysis is gaining strong interest in Europe, especially in Germany where wind penetration is already at critical levels for grid stability. For this application as well as biogas conversion and vehicle fueling, megawatt (MW) scale electrolysis is required. Proton has established a technology roadmap to achieve the necessary cost reductions and manufacturing scale up to maintain U.S. competitiveness in these markets. This project represents a highly successful example of the potential for cost reduction in PEM electrolysis, and provides the initial stack design and manufacturing development for Proton’s MW scale product launch. The majority of the program focused on the bipolar assembly, from electrochemical modeling to subscale stack development through prototyping and manufacturing qualification for a large active area cell platform. Feasibility for an advanced membrane electrode assembly (MEA) with 50% reduction in catalyst loading was also demonstrated. Based on the progress in this program and other parallel efforts, H2A analysis shows the status of PEM electrolysis technology dropping below $3.50/kg production costs, exceeding the 2015 target.

  16. Root cause study on hydrogen generation and explosion through radiation-induced electrolysis in the Fukushima Daiichi accident

    Energy Technology Data Exchange (ETDEWEB)

    Saji, Genn, E-mail: sajig@bd5.so-net.ne.jp

    2016-10-15

    Highlights: • Reviewed how LWRs have coped with “water radiolysis”, during normal operation to severe accidents. • Concluded “water radiolysis” is not likely a route course of the hydrogen explosions at Fukushima. • Performed modeling studies based on “radiation-induced electrolysis” on Unit 1–Unit 4. • Generation of several tens of thousands cubic meters hydrogen gas is predicted before the hydrogen explosions. • Upon SBO, early safe disposal of hydrogen from RPVs is indispensable in BWRs. - Abstract: Since the scientific cause for a series of hydrogen explosions during the Fukushima accident has not been established, the author investigated his basic theory named “radiation-induced electrolysis (RIE)” by applying the estimation of the amounts of H{sub 2} generation during the active phase of the Fukushima accident. The author's theory was originally developed by including Faraday's law of electrolysis into the basic time-dependent material balance equation of radiation-chemical species for his study on accelerated corrosion phenomena which is widely observed in aged plants. As such this theory applies to the early phase of the accident before the loss of water levels in the reactor cores, although the simulations were performed from the time of seismic reactor trip to the hydrogen explosions in this paper. Through this mechanism as much as 29,400 m{sup 3}-STP of hydrogen gas is estimated to be accumulated inside the PCV just prior to the hydrogen explosion which occurred one day after the reactor trip in 1F1. With this large volume of hydrogen gas the explosion was a viable possibility upon the “venting” operation. In view of this observation, hydrogen generation from the spent fuel pools was also investigated. For the investigation of the 1F4 SFP, the pool water temperature and flow velocity due to natural circulation were changed widely to identify conditions of large hydrogen generation. During the trial calculations

  17. 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.

  18. Stabilization of Wind Energy Conversion System with Hydrogen Generator by Using EDLC Energy Storage System

    Science.gov (United States)

    Shishido, Seiji; Takahashi, Rion; Murata, Toshiaki; Tamura, Junji; Sugimasa, Masatoshi; Komura, Akiyoshi; Futami, Motoo; Ichinose, Masaya; Ide, Kazumasa

    The spread of wind power generation is progressed hugely in recent years from a viewpoint of environmental problems including global warming. Though wind power is considered as a very prospective energy source, wind power fluctuation due to the random fluctuation of wind speed has still created some problems. Therefore, research has been performed how to smooth the wind power fluctuation. This paper proposes Energy Capacitor System (ECS) for the smoothing of wind power which consists of Electric Double-Layer Capacitor (EDLC) and power electronics devices and works as an electric power storage system. Moreover, hydrogen has received much attention in recent years from a viewpoint of exhaustion problem of fossil fuel. Therefore it is also proposed that a hydrogen generator is installed at the wind farm to generate hydrogen. In this paper, the effectiveness of the proposed system is verified by the simulation analyses using PSCAD/EMTDC.

  19. Dye-Sensitized Photocatalytic Water Splitting and Sacrificial Hydrogen Generation: Current Status and Future Prospects

    Directory of Open Access Journals (Sweden)

    Pankaj Chowdhury

    2017-05-01

    Full Text Available Today, global warming and green energy are important topics of discussion for every intellectual gathering all over the world. The only sustainable solution to these problems is the use of solar energy and storing it as hydrogen fuel. Photocatalytic and photo-electrochemical water splitting and sacrificial hydrogen generation show a promise for future energy generation from renewable water and sunlight. This article mainly reviews the current research progress on photocatalytic and photo-electrochemical systems focusing on dye-sensitized overall water splitting and sacrificial hydrogen generation. An overview of significant parameters including dyes, sacrificial agents, modified photocatalysts and co-catalysts are provided. Also, the significance of statistical analysis as an effective tool for a systematic investigation of the effects of different factors and their interactions are explained. Finally, different photocatalytic reactor configurations that are currently in use for water splitting application in laboratory and large scale are discussed.

  20. Utilization of hydrogen gas production for electricity generation in ...

    African Journals Online (AJOL)

    Lecturer

    2012-05-03

    % total sugar concentration of sugar ... 107 cfu/ml, pH was nearly constant at 6.0, and finally the H2 was drifted to fuel cell to generate electrical power until 4 V ..... hybrid system, reverse micelles and by metabolic engi- neering.

  1. Operating of Small Wind Power Plants with Induction Generators

    Directory of Open Access Journals (Sweden)

    Jakub Nevrala

    2008-01-01

    Full Text Available This paper describes different systems of small wind power plants with induction generators used in the Czech Republic. Problems of wind power plants running with induction generators are solved within partial target of the research project MSM 6198910007. For small wind power plants is used induction motor as a generator. Parameters of the name plate of motor must be resolved for generator running on measuring base. These generators are running as a separately working generators or generators connected to the power grid. Methods of control these systems as a separately working, directly connecting to power grid, control by frequency converter and wiring by synchronous cascade are confronted on the measuring base too.

  2. Next Generation Nuclear Plant Project Evaluation of Siting a HTGR Co-generation Plant on an Operating Commercial Nuclear Power Plant Site

    International Nuclear Information System (INIS)

    Demick, L.E.

    2011-01-01

    This paper summarizes an evaluation by the Idaho National Laboratory (INL) Next Generation Nuclear Plant (NGNP) Project of siting a High Temperature Gas-cooled Reactor (HTGR) plant on an existing nuclear plant site that is located in an area of significant industrial activity. This is a co-generation application in which the HTGR Plant will be supplying steam and electricity to one or more of the nearby industrial plants.

  3. Next Generation Nuclear Plant Project Evaluation of Siting a HTGR Co-generation Plant on an Operating Commercial Nuclear Power Plant Site

    Energy Technology Data Exchange (ETDEWEB)

    L.E. Demick

    2011-10-01

    This paper summarizes an evaluation by the Idaho National Laboratory (INL) Next Generation Nuclear Plant (NGNP) Project of siting a High Temperature Gas-cooled Reactor (HTGR) plant on an existing nuclear plant site that is located in an area of significant industrial activity. This is a co-generation application in which the HTGR Plant will be supplying steam and electricity to one or more of the nearby industrial plants.

  4. Economical analysis of biofuel products and nuclear plant hydrogen

    International Nuclear Information System (INIS)

    Edwaren Liun

    2011-01-01

    The increasing in oil prices over the last six years is unprecedented that should be seen as a spur to increased efficiency. The surge in oil prices on the world market today is driven by strong demand factors in the depletion of world oil reserves. To replace the fuel oil from the bowels of the earth the various alternatives should be considered, including other crops or vegetable oil production of bio-fuels and hydrogen are produced by high temperature nuclear reactors. Biofuels in the form of ethanol made from corn or sugar cane and biodiesel made from palm oil or jatropha. With the latest world oil prices, future fuel vegetable oil and nuclear hydrogen-based energy technologies become popular in various parts of the world. Economics of biodiesel will be changed in accordance with world oil prices and subsidy regulations which apply to fuel products. On the other hand the role of nuclear energy in hydrogen production with the most potential in the techno-economics is a form of high temperature steam electrolysis, using heat and electricity from nuclear reactors. The production cost of biodiesel fuel on the basis of ADO type subsidy is 10.49 US$/MMBTU, while the production cost of hydrogen as an energy carrier of high temperature reactor is 15.30 US$/MMBTU. Thus, both types seem to have strong competitiveness. (author)

  5. Hydrogen Generation in Microbial Reverse-Electrodialysis Electrolysis Cells Using a Heat-Regenerated Salt Solution

    KAUST Repository

    Nam, Joo-Youn

    2012-05-01

    Hydrogen gas can be electrochemically produced in microbial reverse-electrodialysis electrolysis cells (MRECs) using current derived from organic matter and salinity-gradient energy such as river water and seawater solutions. Here, it is shown that ammonium bicarbonate salts, which can be regenerated using low-temperature waste heat, can also produce sufficient voltage for hydrogen gas generation in an MREC. The maximum hydrogen production rate was 1.6 m3 H2/m3·d, with a hydrogen yield of 3.4 mol H2/mol acetate at a salinity ratio of infinite. Energy recovery was 10% based on total energy applied with an energy efficiency of 22% based on the consumed energy in the reactor. The cathode overpotential was dependent on the catholyte (sodium bicarbonate) concentration, but not the salinity ratio, indicating high catholyte conductivity was essential for maximizing hydrogen production rates. The direction of the HC and LC flows (co- or counter-current) did not affect performance in terms of hydrogen gas volume, production rates, or stack voltages. These results show that the MREC can be successfully operated using ammonium bicarbonate salts that can be regenerated using conventional distillation technologies and waste heat making the MREC a useful method for hydrogen gas production from wastes. © 2012 American Chemical Society.

  6. Availability of steam generator against thermal disturbance of hydrogen production system coupled to HTGR

    International Nuclear Information System (INIS)

    Shibata, Taiju; Nishihara, Tetsuo; Hada, Kazuhiko; Shiozawa, Shusaku

    1996-01-01

    One of the safety issues to couple a hydrogen production system to an HTGR is how the reactor coolability can be maintained against anticipated abnormal reduction of heat removal (thermal disturbance) of the hydrogen production system. Since such a thermal disturbance is thought to frequently occur, it is desired against the thermal disturbance to keep reactor coolability by means other than reactor scram. Also, it is thought that the development of a passive cooling system for such a thermal disturbance will be necessary from a public acceptance point of view in a future HTGR-hydrogen production system. We propose a SG as the passive cooling system which can keep the reactor coolability during a thermal disturbance of a hydrogen production system. This paper describes the proposed steam generator (SG) for the HTGR-hydrogen production system and a result of transient thermal-hydraulic analysis of the total system, showing availability of the SG against a thermal disturbance of the hydrogen production system in case of the HTTR-steam reforming hydrogen production system. (author)

  7. Development of second-generation PFB combustion plants

    Energy Technology Data Exchange (ETDEWEB)

    Robertson, A.; Domeracki, W.; Horazak, D. [and others

    1995-12-31

    Research is being conducted under United States Department of Energy (USDOE) Contract DE-AC21-86MC21023 to develop a new type of coal-fueled plant for electric power generation. This new type of plant--called an Advanced or Second-generation Pressurized Fluidized Bed Combustion (APFBC) plant--offers the promise of efficiencies greater than 45 percent (HHV), with both emissions and a cost of electricity that are significantly lower than conventional pulverized-coal-fired plants with scrubbers. This paper summarizes the pilot-plant R&D work being conducted to develop this new type of plant and discusses a proposed design that should reduce demonstration-plant risks and costs.

  8. Hydrogen co-production from subcritical water-cooled nuclear power plants in Canada

    Energy Technology Data Exchange (ETDEWEB)

    Gnanapragasam, N.; Ryland, D.; Suppiah, S., E-mail: gnanapragasamn@aecl.ca [Atomic Energy of Canada Limited, Chalk River, Ontario (Canada)

    2013-06-15

    Subcritical water-cooled nuclear reactors (Sub-WCR) operate in several countries including Canada providing electricity to the civilian population. The high-temperature-steam-electrolysis process (HTSEP) is a feasible and laboratory-demonstrated large-scale hydrogen-production process. The thermal and electrical integration of the HTSEP with Sub-WCR-based nuclear-power plants (NPPs) is compared for best integration point, HTSEP operating condition and hydrogen production rate based on thermal energy efficiency. Analysis on integrated thermal efficiency suggests that the Sub-WCR NPP is ideal for hydrogen co-production with a combined efficiency of 36%. HTSEP operation analysis suggests that higher product hydrogen pressure reduces hydrogen and integrated efficiencies. The best integration point for the HTSEP with Sub-WCR NPP is upstream of the high-pressure turbine. (author)

  9. Combined heat and power (cogeneration) plant based on renewable energy sources and electrochemical hydrogen systems

    Science.gov (United States)

    Grigor'ev, S. A.; Grigor'ev, A. S.; Kuleshov, N. V.; Fateev, V. N.; Kuleshov, V. N.

    2015-02-01

    The layout of a combined heat and power (cogeneration) plant based on renewable energy sources (RESs) and hydrogen electrochemical systems for the accumulation of energy via the direct and inverse conversion of the electrical energy from RESs into the chemical energy of hydrogen with the storage of the latter is described. Some efficient technical solutions on the use of electrochemical hydrogen systems in power engineering for the storage of energy with a cyclic energy conversion efficiency of more than 40% are proposed. It is shown that the storage of energy in the form of hydrogen is environmentally safe and considerably surpasses traditional accumulator batteries by its capacitance characteristics, being especially topical in the prolonged absence of energy supply from RESs, e.g., under the conditions of polar night and breathless weather. To provide the required heat consumption of an object during the peak period, it is proposed to burn some hydrogen in a boiler house.

  10. Coupling a PEM fuel cell and the hydrogen generation from aluminum waste cans

    Energy Technology Data Exchange (ETDEWEB)

    Martinez, Susana Silva; Albanil Sanchez, Loyda; Alvarez Gallegos, Alberto A. [Centro de Investigacion en Ingenieria y Ciencias Aplicadas, Av. Universidad 1001, Col. Chamilpa, Cuernavaca, Mor. CP 62210 (Mexico); Sebastian, P.J. [Centro de Investigacion en Energia-UNAM, 62580 Temixco, Morelos (Mexico); Cuerpo Academico de Energia y Sustentabilidad, UPCH, Tuxtla Gutierrez, Chiapas (Mexico)

    2007-10-15

    High purity hydrogen was generated from the chemical reaction of aluminum and sodium hydroxide. The aluminum used in this study was obtained from empty soft drink cans and treated with concentrated sulfuric acid to remove the paint and plastic film. One gram of aluminum was reacted with a solution of 2moldm{sup -3} of sodium hydroxide to produce hydrogen. The hydrogen produced from aluminum cans and oxygen obtained from a proton exchange membrane electrolyzer or air, was fed to a proton exchange membrane (PEM) fuel cell to produce electricity. Yields of 44 mmol of hydrogen contained in a volume of 1.760dm{sup 3} were produced from one gram of aluminum in a time period of 20 min. (author)

  11. Understanding oscillatory phenomena in molecular hydrogen generation via sodium borohydride hydrolysis.

    Science.gov (United States)

    Budroni, M A; Biosa, E; Garroni, S; Mulas, G R C; Marchettini, N; Culeddu, N; Rustici, M

    2013-11-14

    The hydrolysis of borohydride salts represents one of the most promising processes for the generation of high purity molecular hydrogen under mild conditions. In this work we show that the sodium borohydride hydrolysis exhibits a fingerprinting periodic oscillatory transient in the hydrogen flow over a wide range of experimental conditions. We disproved the possibility that flow oscillations are driven by supersaturation phenomena of gaseous bubbles in the reactive mixture or by a nonlinear thermal feedback according to a thermokinetic model. Our experimental results indicate that the NaBH4 hydrolysis is a spontaneous inorganic oscillator, in which the hydrogen flow oscillations are coupled to an "oscillophor" in the reactive solution. The discovery of this original oscillator paves the way for a new class of chemical oscillators, with fundamental implications not only for testing the general theory on oscillations, but also with a view to chemical control of borohydride systems used as a source of hydrogen based green fuel.

  12. Catalytic production of hydrogen from methanol for mobile, stationary and portable fuel-cell power plants

    International Nuclear Information System (INIS)

    Lukyanov, Boris N

    2008-01-01

    Main catalytic processes for hydrogen production from methanol are considered. Various schemes of fuel processors for hydrogen production in stationary, mobile and portable power plants based on fuel cells are analysed. The attention is focussed on the design of catalytic reactors of fuel processors and on the state-of-the-art in the design of catalysts for methanol conversion, carbon monoxide steam conversion and carbon monoxide selective oxidation. Prospects for the use of methanol in on-board fuel processors are discussed.

  13. Formic Acid Free Flowsheet Development To Eliminate Catalytic Hydrogen Generation In The Defense Waste Processing

    Energy Technology Data Exchange (ETDEWEB)

    Lambert, Dan P.; Stone, Michael E.; Newell, J. David; Fellinger, Terri L.; Bricker, Jonathan M.

    2012-09-14

    The Defense Waste Processing Facility (DWPF) processes legacy nuclear waste generated at the Savannah River Site (SRS) during production of plutonium and tritium demanded by the Cold War. The nuclear waste is first treated via a complex sequence of controlled chemical reactions and then vitrified into a borosilicate glass form and poured into stainless steel canisters. Converting the nuclear waste into borosilicate glass canisters is a safe, effective way to reduce the volume of the waste and stabilize the radionuclides. Testing was initiated to determine whether the elimination of formic acid from the DWPF's chemical processing flowsheet would eliminate catalytic hydrogen generation. Historically, hydrogen is generated in chemical processing of alkaline High Level Waste sludge in DWPF. In current processing, sludge is combined with nitric and formic acid to neutralize the waste, reduce mercury and manganese, destroy nitrite, and modify (thin) the slurry rheology. The noble metal catalyzed formic acid decomposition produces hydrogen and carbon dioxide. Elimination of formic acid by replacement with glycolic acid has the potential to eliminate the production of catalytic hydrogen. Flowsheet testing was performed to develop the nitric-glycolic acid flowsheet as an alternative to the nitric-formic flowsheet currently being processed at the DWPF. This new flowsheet has shown that mercury can be reduced and removed by steam stripping in DWPF with no catalytic hydrogen generation. All processing objectives were also met, including greatly reducing the Slurry Mix Evaporator (SME) product yield stress as compared to the baseline nitric/formic flowsheet. Ten DWPF tests were performed with nonradioactive simulants designed to cover a broad compositional range. No hydrogen was generated in testing without formic acid.

  14. Mixing of radiolytic hydrogen generated within a containment compartment following a LOCA

    International Nuclear Information System (INIS)

    Willcutt, G.J.E. Jr.; Gido, R.G.

    1978-07-01

    The objective of this work was to determine hydrogen concentration variations with position and time in a closed containment compartment with radiolytic hydrogen generation in the water on the compartment floor following a Loss-of-Coolant-Accident (LOCA). One application is to determine the potential difference between the compartment maximum hydrogen concentration and a hydrogen detector reading, due to the detector location. Three possible mechanisms for hydrogen transport in the compartment were investigated: (1) molecular diffusion, (2) possible bubble formation and motion, and (3) natural convection flows. A base case cubic compartment with 6.55-m (21.5-ft) height was analyzed. Parameter studies were used to determine the sensitivity of results to compartment size, hydrogen generation rates, diffusion coefficients, and the temperature difference between the floor and the ceiling and walls of the compartment. Diffusion modeling indicates that if no other mixing mechanism is present for the base case, the maximum hydrogen volume percent (vol percent) concentration difference between the compartment floor and ceiling will be 4.8 percent. It will be 24.5 days before the maximum concentration difference is less than 0.5 percent. Bubbles do not appear to be a potential source of hydrogen pocketing in a containment compartment. Compartment natural convection circulation rates for a 2.8 K (5 0 F) temperature difference between the floor and the ceiling and walls are estimated to be at least the equivalent of 1 compartment volume per hour and probably in the range of 4 to 9 compartment volumes per hour. Related natural convection studies indicate there will be turbulent mixing in the compartment for a 2.8 K (5 0 F) temperature difference between the floor and the ceiling and walls

  15. Generation of oxy-hydrogen gas and its effect on performance of spark ignition engine

    Science.gov (United States)

    Patil, N. N.; Chavan, C. B.; More, A. S.; Baskar, P.

    2017-11-01

    Considering the current scenario of petroleum fuels, it has been observed that, they will last for few years from now. On the other hand, the ever increasing cost of a gasoline fuels and their related adverse effects on environment caught the attention of researchers to find a supplementary source. For commercial fuels, supplementary source is not about replacing the entire fuel, instead enhancing efficiency by simply making use of it in lesser amount. From the recent research that has been carried out, focus on the use of Hydrogen rich gas as a supplementary source of fuel has increased. But the problem related to the storage of hydrogen gas confines the application of pure hydrogen in petrol engine. Using oxy-hydrogen gas (HHO) generator the difficulties of storing the hydrogen have overcome up to a certain limit. The present study highlights on performance evaluation of conventional petrol engine by using HHO gas as a supplementary fuel. HHO gas was generated from the electrolysis of water. KOH solution of 3 Molar concentration was used which act as a catalyst and accelerates the rate of generation of HHO gas. Quantity of gas to be supplied to the engine was controlled by varying amount of current. It was observed that, engine performance was improved on the introduction of HHO gas.

  16. Hydrogen generation in SRAT with nitric acid and late washing flowsheets

    International Nuclear Information System (INIS)

    Hsu, C.W.

    1992-01-01

    Melter feed preparation processes, incorporating a final wash of the precipitate slurry feed to Defense Waste Processing Facility (DWPF) and a partial substitution of the SRAT formic acid requirement with nitric acid, should not produce peak hydrogen generation rates during Cold Chemical Runs (CCR's) and radioactive operation greater than their current, respective hydrogen design bases of 0.024 lb/hr and 1.5 lb/hr. A single SRAT bench-scale process simulation for CCR-s produced a DWPF equivalent peak hydrogen generation rate of 0.004 lb/hr. During radioactive operation, the peak hydrogen generation rate will be dependent on the extent DWPF deviates from the nominal precipitate hydrolysis and melter feed preparation process operating parameters. Two actual radioactive sludges were treated according to the new flowsheets. The peak hydrogen evolution rates were equivalent to 0.038 and 0.20 lb/hr (DWPF scale) respectively. Compared to the formic acid -- HAN hydrolysis flowsheets, these peak rates were reduced by a factor of 2.5 and 3.4 for Tank 15 and Tank 11 sludges, respectively

  17. Global Assessment of Hydrogen Technologies – Task 5 Report Use of Fuel Cell Technology in Electric Power Generation

    Energy Technology Data Exchange (ETDEWEB)

    Fouad, Fouad H.; Peters, Robert W.; Sisiopiku, Virginia P.; Sullivan Andrew J.; Ahluwalia, Rajesh K.

    2007-12-01

    . Photovoltaic cells convert sunlight into electricity. This electricity can be used to split water (electrolysis) into hydrogen and oxygen, to store the sun's energy as hydrogen fuel. In this scenario, fuel cell powered vehicles or generating stations have no real emissions of greenhouse or acid gases, or any other pollutants. It is predominantly during the fuel processing stage that atmospheric emissions are released by a fuel cell power plant. When methanol from biomass is used as a fuel, fuel cells have no net emissions of carbon dioxide (CO2, a greenhouse gas) because any carbon released was recently taken from the atmosphere by photosynthetic plants. Any high temperature combustion, such as that which would take place in a spark ignition engine fueled by methanol, produces nitrous oxides (NOx), gases which contribute to acid rain. Fuel cells virtually eliminate NOx emissions because of the lower temperatures of their chemical reactions. Fuel cells, using processed fossil fuels, have emissions of CO2 and sulfur dioxide (SO2) but these emissions are much lower than those from traditional thermal power plants or spark ignition engines due to the higher efficiency of fuel cell power plants. Higher efficiencies result in less fuel being consumed to produce a given amount of electricity or to travel a given distance. This corresponds to lower CO2 and SO2 emissions. Fuel cell power plants also have longer life expectancies and lower maintenance costs than their alternatives.

  18. Plant concept of heat utilization of high temperature gas-cooled reactors. Co-generation and coal-gasification

    International Nuclear Information System (INIS)

    Tonogouchi, M.; Maeda, S.; Ide, A.

    1996-01-01

    In Japan, JAERI is now constructing the High temperature Engineering Test Reactor (HTTR) and the new era is coming for the development and utilization of HTR. Recognizing that the heat utilization of HTR would mitigate problems of environment and resources and contribute the effective use and steady supply of the energy, FAPIG organized a working group named 'HTR-HUC' to study the heat utilization of HTR in the field other than electric power generation. We chose three kinds of plants to study, 1) a co-generation plant in which the existing power units supplying steam and electricity can be replaced by a nuclear plant, 2) Coal gasification plant which can accelerate the clean use of coal and contribute stable supply of the energy and preservation of the environment in the world and 3) Hydrogen production plant which can help to break off the use of the new energy carrier HYDROGEN and will release people from the dependence of fossil energy. In this paper the former two plants, Co-generation chemical plant and Coal-gasification plant are focussed on. The main features, process flow and safety assessment of these plants are discussed. (J.P.N.)

  19. Start up system for hydrogen generator used with an internal combustion engine

    Science.gov (United States)

    Houseman, J.; Cerini, D. J. (Inventor)

    1977-01-01

    A hydrogen generator provides hydrogen rich product gases which are mixed with the fuel being supplied to an internal combustion engine for the purpose of enabling a very lean mixture of that fuel to be used, whereby nitrous oxides emitted by the engine are minimized. The hydrogen generator contains a catalyst which must be heated to a pre-determined temperature before it can react properly. To simplify the process of heating up the catalyst at start-up time, either some of the energy produced by the engine such as engine exhaust gas, or electrical energy produced by the engine, or the engine exhaust gas may be used to heat up air which is then used to heat the catalyst.

  20. Modeling the reaction kinetics of a hydrogen generator onboard a fuel cell -- Electric hybrid motorcycle

    Science.gov (United States)

    Ganesh, Karthik

    Owing to the perceived decline of the fossil fuel reserves in the world and environmental issues like pollution, conventional fuels may be replaced by cleaner alternative fuels. The potential of hydrogen as a fuel in vehicular applications is being explored. Hydrogen as an energy carrier potentially finds applications in internal combustion engines and fuel cells because it is considered a clean fuel and has high specific energy. However, at 6 to 8 per kilogram, not only is hydrogen produced from conventional methods like steam reforming expensive, but also there are storage and handling issues, safety concerns and lack of hydrogen refilling stations across the country. The purpose of this research is to suggest a cheap and viable system that generates hydrogen on demand through a chemical reaction between an aluminum-water slurry and an aqueous sodium hydroxide solution to power a 2 kW fuel cell on a fuel cell hybrid motorcycle. This reaction is essentially an aluminum-water reaction where sodium hydroxide acts as a reaction promoter or catalyst. The Horizon 2000 fuel cell used for this purpose has a maximum hydrogen intake rate of 28 lpm. The study focuses on studying the exothermic reaction between the reactants and proposes a rate law that best describes the rate of generation of hydrogen in connection to the surface area of aluminum available for the certain reaction and the concentration of the sodium hydroxide solution. Further, the proposed rate law is used in the simulation model of the chemical reactor onboard the hybrid motorcycle to determine the hydrogen flow rate to the fuel cell with time. Based on the simulated rate of production of hydrogen from the chemical system, its feasibility of use on different drive cycles is analyzed. The rate of production of hydrogen with a higher concentration of sodium hydroxide and smaller aluminum powder size was found to enable the installation of the chemical reactor on urban cycles with frequent stops and starts

  1. The assesment on safety distance determination of hydrogen production plant with RGTT200K reactor

    International Nuclear Information System (INIS)

    Siti Alimah; Sriyono

    2013-01-01

    The one of the hydrogen production process method coupled to RGTT200K is the utilization of steam reforming with (methane) natural gas as the feedstock. The integration between RGTT200K and hydrogen plant must consider many safety aspects and one of it is separation distance between these two systems. The purpose of this assessment is to study the sources of fires/explosion and to determine the safety distance between the steam reforming hydrogen production plant and RGTT200K reactor. The used methodology was literature assessment and safety distance calculation with equation R = k.W 1/3 . In this studi, safety distance determination in integration between RGTT200K and hydrogen plant was using equation based on reference of the USNRC Regulatory Guide 1.91 and mass on the equation was mass equivalent of TNT (kg). The results of the study show the hydrogen plant produces 160.000 m 3 /day, if requires storage tanks of 400.000 m 3 (based USNRC equal to 1.859 million tons of TNT equivalent) with factor k is 8, based on the equation R = k.W 1/3 , so the requirement for safety distance is 1 km. This distance may be shortened by adding a fire proof wall barrier and requires further assessment. (author)

  2. Turbines, generators and associated plant incorporating modern power system practice

    CERN Document Server

    Littler, DJ

    1992-01-01

    The introduction of new 500 MW and 660 MW turbine generator plant in nuclear, coal- and oil-fired power stations has been partly responsible for the increase in generating capacity of the CEGB over the last 30 years. This volume provides a detailed account of experience gained in the development, design, manufacture, operation and testing of large turbine-generators in the last 20 years. With the advance in analytical and computational techniques, the application of this experience to future design and operation of large turbine-generator plant will be of great value to engineers in the indust

  3. Nuclear-produced hydrogen by a thermochemical Cu-Cl plant for passenger hydrogen trains

    International Nuclear Information System (INIS)

    Marin, G.; Naterer, G.; Gabriel, K.

    2010-01-01

    This paper compares the technical and economic aspects of electrification of a passenger-train operation in Ontario Canada, versus operation with hydrogen trains using nuclear-produced hydrogen. A local GO Transit diesel operation in Ontario has considered electrification as an alternative to reduce greenhouse gas emissions of passenger trains in the Toronto area. Hydrogen production from nuclear energy via a thermo-chemical Copper-Chlorine (Cu-Cl) cycle for train operation is shown to have lower emissions than direct electrification. It significantly reduces the greenhouse gas emissions compared to diesel operation. A bench-mark reference case used for the nuclear thermo-chemical Cu-Cl cycle is the Sulfur-Iodine (S-I) cycle, under investigation in the USA, Japan, and France, among others. The comparative study in this paper considers a base case of diesel operated passenger trains, within the context of a benefits case analysis for train electrification, for GO Transit operations in Toronto, and the impact of each cost component is discussed. The cost analysis includes projected prices of fuel cell trains, with reference to studies performed by train operators. (author)

  4. Korea's choice of a new generation of nuclear plants

    International Nuclear Information System (INIS)

    Redding, J.R.

    1994-01-01

    The ABWR and SBWR design, both under development at GE, provide the best platform for developing the next generation advanced plants. The ABWR, which is rapidly setting the standard for new nuclear reactor plants, is clearly the best choice to meet the present energy needs of Korea. And through a GE/Korea partnership to develop the plant of the next century, Korea will establish itself as a leader in innovative reactor technology

  5. Sizing Hydrogen Energy Storage in Consideration of Demand Response in Highly Renewable Generation Power Systems

    Directory of Open Access Journals (Sweden)

    Mubbashir Ali

    2018-05-01

    Full Text Available From an environment perspective, the increased penetration of wind and solar generation in power systems is remarkable. However, as the intermittent renewable generation briskly grows, electrical grids are experiencing significant discrepancies between supply and demand as a result of limited system flexibility. This paper investigates the optimal sizing and control of the hydrogen energy storage system for increased utilization of renewable generation. Using a Finnish case study, a mathematical model is presented to investigate the optimal storage capacity in a renewable power system. In addition, the impact of demand response for domestic storage space heating in terms of the optimal sizing of energy storage is discussed. Finally, sensitivity analyses are conducted to observe the impact of a small share of controllable baseload production as well as the oversizing of renewable generation in terms of required hydrogen storage size.

  6. Transport of high fluxes of hydrogen plasma in a linear plasma generator

    NARCIS (Netherlands)

    Vijvers, W.A.J.; Al, R.S.; Lopes Cardozo, N.J.; Goedheer, W.J.; Groot, de B.; Kleyn, A.W.; Meiden, van der H.J.; Peppel, van de R.J.E.; Schram, D.C.; Shumack, A.E.; Westerhout, J.; Rooij, van G.J.; Schmidt, J.; Simek, M.; Pekarek, S.; Prukner, V.

    2007-01-01

    A study was made to quantify the losses during the convective hydrogen plasma transport in the linear plasma generator Pilot-PSI due to volume recombination. A transport efficiency of 35% was achieved at neutral background pressures below ~7 Pa in a magnetic field of 1.2 T. This efficiency decreased

  7. Turning the wind into hydrogen: The long-run impact on electricity prices and generating capacity

    International Nuclear Information System (INIS)

    Green, Richard; Hu, Helen; Vasilakos, Nicholas

    2011-01-01

    Hydrogen production via electrolysis has been proposed as a way of absorbing the fluctuating electricity generated by wind power, potentially allowing the use of cheap electricity at times when it would otherwise be in surplus. We show that large-scale adoption of electrolysers would change the shape of the load-duration curve for electricity, affecting the optimal capacity mix. Nuclear power stations will replace gas-fired power stations, as they are able to run for longer periods of time. Changes in the electricity capacity mix will be much greater than changes to the pattern of prices. The long-run supply price of hydrogen will thus tend to be insensitive to the amount produced. - Research Highlights: → Hydrogen production from electrolysis may offset intermittent wind generation. → The generation capacity mix will change in response to changed demand patterns. → The long-run equilibrium supply curve for hydrogen will be quite flat. → The production cost will be very sensitive to fuel prices paid by generators.

  8. Porous layered double hydroxides synthesized using oxygen generated by decomposition of hydrogen peroxide

    NARCIS (Netherlands)

    Gonzalez Rodriguez, P.; de Ruiter, M.P.; Wijnands, Tom; ten Elshof, Johan E.

    2017-01-01

    Porous magnesium-aluminium layered double hydroxides (LDH) were prepared through intercalation and decomposition of hydrogen peroxide (H2O2). This process generates oxygen gas nano-bubbles that pierce holes in the layered structure of the material by local pressure build-up. The decomposition of the

  9. 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

  10. Microbial Photoelectrosynthesis for Self-Sustaining Hydrogen Generation.

    Science.gov (United States)

    Lu, Lu; Williams, Nicholas B; Turner, John A; Maness, Pin-Ching; Gu, Jing; Ren, Zhiyong Jason

    2017-11-21

    Current artificial photosynthesis (APS) systems are promising for the storage of solar energy via transportable and storable fuels, but the anodic half-reaction of water oxidation is an energy intensive process which in many cases poorly couples with the cathodic half-reaction. Here we demonstrate a self-sustaining microbial photoelectrosynthesis (MPES) system that pairs microbial electrochemical oxidation with photoelectrochemical water reduction for energy efficient H 2 generation. MPES reduces the overall energy requirements thereby greatly expanding the range of semiconductors that can be utilized in APS. Due to the recovery of chemical energy from waste organics by the mild microbial process and utilization of cost-effective and stable catalyst/electrode materials, our MPES system produced a stable current of 0.4 mA/cm 2 for 24 h without any external bias and ∼10 mA/cm 2 with a modest bias under one sun illumination. This system also showed other merits, such as creating benefits of wastewater treatment and facile preparation and scalability.

  11. Fuel processor and method for generating hydrogen for fuel cells

    Science.gov (United States)

    Ahmed, Shabbir [Naperville, IL; Lee, Sheldon H. D. [Willowbrook, IL; Carter, John David [Bolingbrook, IL; Krumpelt, Michael [Naperville, IL; Myers, Deborah J [Lisle, IL

    2009-07-21

    A method of producing a H.sub.2 rich gas stream includes supplying an O.sub.2 rich gas, steam, and fuel to an inner reforming zone of a fuel processor that includes a partial oxidation catalyst and a steam reforming catalyst or a combined partial oxidation and stream reforming catalyst. The method also includes contacting the O.sub.2 rich gas, steam, and fuel with the partial oxidation catalyst and the steam reforming catalyst or the combined partial oxidation and stream reforming catalyst in the inner reforming zone to generate a hot reformate stream. The method still further includes cooling the hot reformate stream in a cooling zone to produce a cooled reformate stream. Additionally, the method includes removing sulfur-containing compounds from the cooled reformate stream by contacting the cooled reformate stream with a sulfur removal agent. The method still further includes contacting the cooled reformate stream with a catalyst that converts water and carbon monoxide to carbon dioxide and H.sub.2 in a water-gas-shift zone to produce a final reformate stream in the fuel processor.

  12. Targeted enrichment strategies for next-generation plant biology

    Science.gov (United States)

    Richard Cronn; Brian J. Knaus; Aaron Liston; Peter J. Maughan; Matthew Parks; John V. Syring; Joshua. Udall

    2012-01-01

    The dramatic advances offered by modem DNA sequencers continue to redefine the limits of what can be accomplished in comparative plant biology. Even with recent achievements, however, plant genomes present obstacles that can make it difficult to execute large-scale population and phylogenetic studies on next-generation sequencing platforms. Factors like large genome...

  13. Generation IV nuclear plant design strategies

    International Nuclear Information System (INIS)

    Altin, V.

    2007-01-01

    In this presentation Generation IV nuclear reactor design criteria are examined under the light of known nuclear properties of fissile and fertile nuclei. Their conflicting nature is elucidated along with the resulting inevitability of a multitude of designs. The designs selected as candidates for further development are evaluated with respect to their potential to serve the different design criteria, thereby revealing their more difficult aspects of realization and the strong research challenges lying ahead

  14. Evaluation of the pressure loads generated by hydrogen explosion in auxiliary nuclear building

    International Nuclear Information System (INIS)

    Ahmed Bentaib; Alexandre Bleyer; Pierre Pailhories; Jean-Pierre L'heriteau; Bernard Chaumont; Jerome Dupas; Jerome Riviere

    2005-01-01

    Full text of publication follows: In the framework of nuclear safety, a hydrogen leaks in the auxiliary nuclear building would raise a explosion hazard. A local ignition of the combustible mixture would give birth initially to a slow flame, rapidly accelerated by obstacles. This flame acceleration is responsible for high pressure loads that can damage the auxiliary building and destroy safety equipments in it. In this paper, we evaluate the pressure loads generated by an hydrogen explosion for both bounding and realistic explosion scenarios. The bounding scenarios use stoichiometric hydrogen-air mixtures and the realistic scenarios correspond to hydrogen leaks with mass flow rate varying between 1 g/s and 9 g/s. For every scenario, the impact of the ignition location and ignition time are investigated. The hydrogen dispersion and explosion are computed using the TONUS code. The dispersion model used is based on a finite element solver and the explosion is simulated by a structured finite volumes EULER equation solver and the combustion model CREBCOM which simulates the hydrogen/air turbulent flame propagation, taking into account 3D complex geometry and reactants concentration gradients. The pressure loads computed are then used to investigate the occurrence of a mechanical failure of the tanks located in the auxiliary nuclear building and containing radioactive fluids. The EUROPLEXUS code is used to perform 3D mechanical calculations because the loads are non uniform and of rather short deviation. (authors)

  15. Hydrogen generation from natural gas for the fuel cell systems of tomorrow

    Science.gov (United States)

    Dicks, Andrew L.

    In most cases hydrogen is the preferred fuel for use in the present generation of fuel cells being developed for commercial applications. Of all the potential sources of hydrogen, natural gas offers many advantages. It is widely available, clean, and can be converted to hydrogen relatively easily. When catalytic steam reforming is used to generate hydrogen from natural gas, it is essential that sulfur compounds in the natural gas are removed upstream of the reformer and various types of desulfurisation processes are available. In addition, the quality of fuel required for each type of fuel cell varies according to the anode material used, and the cell temperature. Low temperature cells will not tolerate high concentrations of carbon monoxide, whereas the molten fuel cell (MCFC) and solid oxide fuel cell (SOFC) anodes contain nickel on which it is possible to electrochemically oxidise carbon monoxide directly. The ability to internally reform fuel gas is a feature of the MCFC and SOFC. Internal reforming can give benefits in terms of increased electrical efficiency owing to the reduction in the required cell cooling and therefore parasitic system losses. Direct electrocatalysis of hydrocarbon oxidation has been the elusive goal of fuel cell developers over many years and recent laboratory results are encouraging. This paper reviews the principal methods of converting natural gas into hydrogen, namely catalytic steam reforming, autothermic reforming, pyrolysis and partial oxidation; it reviews currently available purification techniques and discusses some recent advances in internal reforming and the direct use of natural gas in fuel cells.

  16. Hydrogen sulfide generation in shipboard oily-water waste. Part 3. Ship factors

    Energy Technology Data Exchange (ETDEWEB)

    Hodgeman, D.K.; Fletcher, L.E.; Upsher, F.J.

    1995-04-01

    The chemical and microbiological composition of bilge-water in ships of the Royal Australian Navy has been investigated in relation to the formation of hydrogen sulfide by sulfate-reducing bacteria. Sulfate-reducing bacteria were found in most ships in populations up to 800,000 per mL. Sulfate in the wastes is provided by sea-water. Sea-water constitutes up to 60% (median 20%) of the wastes analysed. Evidence for generation of hydrogen sulfide in the ships was found directly as sulfide or indirectly as depressed sulfate concentrations. The low levels of sulfide found in bilge-water from machinery spaces suggested the ventilation systems were effectively removing the gas from the working area. The effect of storage of the wastes under conditions which simulated the oily- water holding tanks of ships were also investigated. Some wastes were found to produce large quantities of hydrogen sulfide on storage. The wastes that failed to produce hydrogen sulfide were investigated to identify any specific nutritional deficiencies. Some organic substances present in bilge-water, such as lactate or biodegradable cleaning agents, and phosphate strongly influenced the generation of hydrogen sulfide in stored oily-water wastes.

  17. Origin of excess heat generated during loading Pd-impregnated alumina powder with deuterium and hydrogen

    Energy Technology Data Exchange (ETDEWEB)

    Dmitriyeva, O., E-mail: olga.dmitriyeva@colorado.edu [Department of Electrical, Computer, and Energy Engineering, University of Colorado, Boulder, CO 80309-0425 (United States); Coolescence LLC, 2450 Central Ave Ste F, Boulder, CO 80301 (United States); Cantwell, R.; McConnell, M. [Coolescence LLC, 2450 Central Ave Ste F, Boulder, CO 80301 (United States); Moddel, G. [Department of Electrical, Computer, and Energy Engineering, University of Colorado, Boulder, CO 80309-0425 (United States)

    2012-09-10

    Highlights: Black-Right-Pointing-Pointer We studied heat produced by hydrogen and deuterium in Pd-impregnated alumina powder. Black-Right-Pointing-Pointer Samples were fabricated using light and heavy water isotopes and varied the gas used for loading. Black-Right-Pointing-Pointer Incorporation of hydrogen and deuterium influenced the amount of heat released or consumed. Black-Right-Pointing-Pointer Pd nanoparticles appear to catalyze hydrogen/deuterium (H/D) exchange chemical reactions. Black-Right-Pointing-Pointer Anomalous heating can be accounted for by chemical rather than nuclear reactions. - Abstract: We studied heat production in Pd-impregnated alumina powder in the presence of hydrogen and deuterium gases, investigating claims of anomalous heat generated as a result of nuclear fusion, usually referred to as a low energy nuclear reaction (LENR). By selecting the water isotope used to fabricate the material and then varying the gas used for loading, we were able to influence the amount of heat released or consumed. We suggest that Pd in its nanoparticle form catalyzes hydrogen/deuterium (H/D) exchange reactions in the material. This hypothesis is supported by heat measurements, residual gas analysis (RGA) data, and calculations of energy available from H/D exchange reactions. Based on the results we conclude that the origin of the anomalous heat generated during deuterium loading of Pd-enriched alumina powder is chemical rather than nuclear.

  18. Origin of excess heat generated during loading Pd-impregnated alumina powder with deuterium and hydrogen

    International Nuclear Information System (INIS)

    Dmitriyeva, O.; Cantwell, R.; McConnell, M.; Moddel, G.

    2012-01-01

    Highlights: ► We studied heat produced by hydrogen and deuterium in Pd-impregnated alumina powder. ► Samples were fabricated using light and heavy water isotopes and varied the gas used for loading. ► Incorporation of hydrogen and deuterium influenced the amount of heat released or consumed. ► Pd nanoparticles appear to catalyze hydrogen/deuterium (H/D) exchange chemical reactions. ► Anomalous heating can be accounted for by chemical rather than nuclear reactions. - Abstract: We studied heat production in Pd-impregnated alumina powder in the presence of hydrogen and deuterium gases, investigating claims of anomalous heat generated as a result of nuclear fusion, usually referred to as a low energy nuclear reaction (LENR). By selecting the water isotope used to fabricate the material and then varying the gas used for loading, we were able to influence the amount of heat released or consumed. We suggest that Pd in its nanoparticle form catalyzes hydrogen/deuterium (H/D) exchange reactions in the material. This hypothesis is supported by heat measurements, residual gas analysis (RGA) data, and calculations of energy available from H/D exchange reactions. Based on the results we conclude that the origin of the anomalous heat generated during deuterium loading of Pd-enriched alumina powder is chemical rather than nuclear.

  19. Improved estimates of separation distances to prevent unacceptable damage to nuclear power plant structures from hydrogen detonation for gaseous hydrogen storage. Technical report

    International Nuclear Information System (INIS)

    1994-05-01

    This report provides new estimates of separation distances for nuclear power plant gaseous hydrogen storage facilities. Unacceptable damage to plant structures from hydrogen detonations will be prevented by having hydrogen storage facilities meet separation distance criteria recommended in this report. The revised standoff distances are based on improved calculations on hydrogen gas cloud detonations and structural analysis of reinforced concrete structures. Also, the results presented in this study do not depend upon equivalencing a hydrogen detonation to an equivalent TNT detonation. The static and stagnation pressures, wave velocity, and the shock wave impulse delivered to wall surfaces were computed for several different size hydrogen explosions. Separation distance equations were developed and were used to compute the minimum separation distance for six different wall cases and for seven detonating volumes (from 1.59 to 79.67 lbm of hydrogen). These improved calculation results were compared to previous calculations. The ratio between the separation distance predicted in this report versus that predicted for hydrogen detonation in previous calculations varies from 0 to approximately 4. Thus, the separation distances results from the previous calculations can be either overconservative or unconservative depending upon the set of hydrogen detonation parameters that are used. Consequently, it is concluded that the hydrogen-to-TNT detonation equivalency utilized in previous calculations should no longer be used

  20. Hydrogen sulfide in plants: from dissipation of excess sulfur to signaling molecule.

    Science.gov (United States)

    Calderwood, Alexander; Kopriva, Stanislav

    2014-09-15

    Sulfur is essential in all organisms for the synthesis of amino acids cysteine and methionine and as an active component of numerous co-factors and prosthetic groups. However, only plants, algae, fungi, and some prokaryotes are capable of using the abundant inorganic source of sulfur, sulfate. Plants take sulfate up, reduce it, and assimilate into organic compounds with cysteine being the first product of the pathway and a donor of reduced sulfur for synthesis of other S-containing compounds. Cysteine is formed in a reaction between sulfide, derived from reduction of sulfite and an activated amino acid acceptor, O-acetylserine. Sulfide is thus an important intermediate in sulfur metabolism, but numerous other functions in plants has been revealed. Hydrogen sulfide can serve as an alternative source of sulfur for plants, which may be significant in anaerobic conditions of waterlogged soils. On the other hand, emissions of hydrogen sulfide have been detected from many plant species. Since the amount of H2S discharged correlated with sulfate supply to the plants, the emissions were considered a mechanism for dissipation of excess sulfur. Significant hydrogen sulfide emissions were also observed in plants infected with pathogens, particularly with fungi. H2S thus seems to be part of the widely discussed sulfur-induced-resistance/sulfur-enhanced-defense. Recently, however, more evidence has emerged for a role for H2S in regulation and signaling. Sulfide stabilizes the cysteine synthase complex, increasing so the synthesis of its acceptor O-acetylserine. H2S has been implicating in regulation of plant stress response, particularly draught stress. There are more and more examples of processes regulated by H2S in plants being discovered, and hydrogen sulfide is emerging as an important signaling molecule, similar to its role in the animal and human world. How similar the functions, and homeostasis of H2S are in these diverse organisms, however, remains to be elucidated

  1. A polymer electrolyte fuel cell stack for stationary power generation from hydrogen fuel

    Energy Technology Data Exchange (ETDEWEB)

    Gottesfeld, S. [Los Alamos National Lab., NM (United States)

    1995-09-01

    The fuel cell is the most efficient device for the conversion of hydrogen fuel to electric power. As such, the fuel cell represents a key element in efforts to demonstrate and implement hydrogen fuel utilization for electric power generation. The low temperature, polymer electrolyte membrane fuel cell (PEMFC) has recently been identified as an attractive option for stationary power generation, based on the relatively simple and benign materials employed, the zero-emission character of the device, and the expected high power density, high reliability and low cost. However, a PEMFC stack fueled by hydrogen with the combined properties of low cost, high performance and high reliability has not yet been demonstrated. Demonstration of such a stack will remove a significant barrier to implementation of this advanced technology for electric power generation from hydrogen. Work done in the past at LANL on the development of components and materials, particularly on advanced membrane/electrode assemblies (MEAs), has contributed significantly to the capability to demonstrate in the foreseeable future a PEMFC stack with the combined characteristics described above. A joint effort between LANL and an industrial stack manufacturer will result in the demonstration of such a fuel cell stack for stationary power generation. The stack could operate on hydrogen fuel derived from either natural gas or from renewable sources. The technical plan includes collaboration with a stack manufacturer (CRADA). It stresses the special requirements from a PEMFC in stationary power generation, particularly maximization of the energy conversion efficiency, extension of useful life to the 10 hours time scale and tolerance to impurities from the reforming of natural gas.

  2. Hydrogen from renewable energy: A pilot plant for thermal production and mobility

    Science.gov (United States)

    Degiorgis, L.; Santarelli, M.; Calì, M.

    In the mainframe of a research contract, a feasibility pre-design study of a hydrogen-fuelled Laboratory-Village has been carried out: the goals are the design and the simulation of a demonstration plant based on hydrogen as primary fuel. The hydrogen is produced by electrolysis, from electric power produced by a mix of hydroelectric and solar photovoltaic plants. The plant will be located in a small remote village in Valle d'Aosta (Italy). This country has large water availability from glaciers and mountains, so electricity production from fluent water hydroelectric plants is abundant and cheap. Therefore, the production of hydrogen during the night (instead of selling the electricity to the grid at very low prices) could become a good economic choice, and hydrogen could be a competitive local fuel in term of costs, if compared to oil or gas. The H 2 will be produced and stored, and used to feed a hydrogen vehicle and for thermal purposes (heating requirement of three buildings), allowing a real field test (Village-Laboratory). Due to the high level of pressure requested for H 2 storage on-board in the vehicle, the choice has been the experimental test of a prototype laboratory-scale high-pressure PEM electrolyzer: a test laboratory has been designed, to investigate the energy savings related to this technology. In the paper, the description of the dynamic simulation of the plant (developed with TRNSYS) together with a detailed design and an economic analysis (proving the technical and economical feasibility of the installation) has been carried out. Moreover, the design of the high-pressure PEM electrolyzer is described.

  3. Coupling of copper-chloride hybrid thermochemical water splitting cycle with a desalination plant for hydrogen production from nuclear energy

    International Nuclear Information System (INIS)

    Orhan, Mehmet F.; Dincer, Ibrahim; Naterer, Greg F.; Rosen, Marc A.

    2010-01-01

    Energy and environmental concerns have motivated research on clean energy resources. Nuclear energy has the potential to provide a significant share of energy supply without contributing to environmental emissions and climate change. Nuclear energy has been used mainly for electric power generation, but hydrogen production via thermochemical water decomposition provides another pathway for the utilization of nuclear thermal energy. One option for nuclear-based hydrogen production via thermochemical water decomposition uses a copper-chloride (Cu-Cl) cycle. Another societal concern relates to supplies of fresh water. Thus, to avoid causing one problem while solving another, hydrogen could be produced from seawater rather than limited fresh water sources. In this study we analyze a coupling of the Cu-Cl cycle with a desalination plant for hydrogen production from nuclear energy and seawater. Desalination technologies are reviewed comprehensively to determine the most appropriate option for the Cu-Cl cycle and a thermodynamic analysis and several parametric studies of this coupled system are presented for various configurations. (author)

  4. NOBLE METAL CHEMISTRY AND HYDROGEN GENERATION DURING SIMULATED DWPF MELTER FEED PREPARATION

    Energy Technology Data Exchange (ETDEWEB)

    Koopman, D

    2008-06-25

    Simulations of the Defense Waste Processing Facility (DWPF) Chemical Processing Cell vessels were performed with the primary purpose of producing melter feeds for the beaded frit program plus obtaining samples of simulated slurries containing high concentrations of noble metals for off-site analytical studies for the hydrogen program. Eight pairs of 22-L simulations were performed of the Sludge Receipt and Adjustment Tank (SRAT) and Slurry Mix Evaporator (SME) cycles. These sixteen simulations did not contain mercury. Six pairs were trimmed with a single noble metal (Ag, Pd, Rh, or Ru). One pair had all four noble metals, and one pair had no noble metals. One supporting 4-L simulation was completed with Ru and Hg. Several other 4-L supporting tests with mercury have not yet been performed. This report covers the calculations performed on SRNL analytical and process data related to the noble metals and hydrogen generation. It was originally envisioned as a supporting document for the off-site analytical studies. Significant new findings were made, and many previous hypotheses and findings were given additional support as summarized below. The timing of hydrogen generation events was reproduced very well within each of the eight pairs of runs, e.g. the onset of hydrogen, peak in hydrogen, etc. occurred at nearly identical times. Peak generation rates and total SRAT masses of CO{sub 2} and oxides of nitrogen were reproduced well. Comparable measures for hydrogen were reproduced with more variability, but still reasonably well. The extent of the reproducibility of the results validates the conclusions that were drawn from the data.

  5. Next Generation Nuclear Plant Pre-Conceptual Design Report

    International Nuclear Information System (INIS)

    Larry Demick; Doug Vandel

    2007-01-01

    The Next Generation Nuclear Plant (NGNP) will be a demonstration of the technical, licensing, operational, and commercial viability of High Temperature Gas-Cooled Reactor (HTGR) technology for the production of process heat, electricity, and hydrogen. This nuclear based technology can provide high-temperature process heat (up to 950 C) that can be used as a substitute for the burning of fossil fuels for a wide range of commercial applications. The substitution of the HTGR for burning fossil fuels conserves these hydrocarbon resources for other uses, reduces uncertainty in the cost and supply of natural gas and oil, and eliminates the emissions of greenhouse gases attendant with the burning of these fuels. The HTGR is a passively1 safe nuclear reactor concept with an easily understood safety basis that permits substantially reduced emergency planning requirements and improved siting flexibility compared to current and advanced light water reactors (LWRs). In the Energy Policy Act of 2005 (EPAct), the Department of Energy (DOE) was tasked with providing a demonstration of this HTGR technology to economically and reliably produce electricity and hydrogen by the year 2021. As the lead nuclear technology development laboratory of the DOE, the Idaho National Laboratory (INL) has initiated the work necessary to complete this task. The EPAct also stipulated that the task should be undertaken in partnership with the industrial end users of the technology. To that end, a working group has been assembled consisting of suppliers of the technology, nuclear plant owner/operators, other supportive technology companies, and potential end users. The objective of the working group is to form an Alliance that would provide the private sector perspective and direction for completion of the NGNP in partnership with the DOE. The Alliance will support the selection of the specific operating conditions and configuration for NGNP to ensure it meets private sector expectations, commence

  6. Microbiome selection could spur next-generation plant breeding strategies

    Directory of Open Access Journals (Sweden)

    Murali Gopal

    2016-12-01

    Full Text Available Plants, though sessile, have developed a unique strategy to counter biotic and abiotic stresses by symbiotically co-evolving with microorganisms and tapping into their genome for this purpose. Soil is the bank of microbial diversity from which a plant selectively sources its microbiome to suit its needs. Besides soil, seeds, which carry the genetic blueprint of plants during trans-generational propagation, are home to diverse microbiota that acts as the principal source of microbial inoculum in crop cultivation. Overall, a plant is ensconced both on the outside and inside with a diverse assemblage of microbiota. Together, the plant genome and the genes of the microbiota that the plant harbours in different plant tissues i.e the ‘plant microbiome’, form the holobiome which is now considered as unit of selection: ‘the holobiont’. The ‘plant microbiome’ not only helps plants to remain fit but also offers critical genetic variability, hitherto, not employed in the breeding strategy by plant breeders, who traditionally have exploited the genetic variability of the host for developing high yielding or disease tolerant or drought resistant varieties. This fresh knowledge of the microbiome, particularly of the rhizosphere, offering genetic variability to plants, opens up new horizons for breeding that could usher in cultivation of next-generation crops depending less on inorganic inputs, resistant to insect pest and diseases and resilient to climatic perturbations. We surmise, from ever increasing evidences, that plants and their microbial symbionts need to be co-propagated as life-long partners in future strategies for plant breeding.

  7. Photocatalytic hydrogen generation over Eosin Y-Sensitized TS-1 zeolite

    International Nuclear Information System (INIS)

    Zhang Xiaojie; Jin Zhiliang; Li Yuexiang; Li Shuben; Lu Gongxuan

    2008-01-01

    Eosin Y-sensitized TS-1 zeolite was studied for the photo-reduction of water into hydrogen driven by visible light (λ ≥ 420 nm). The optimal pH and weight ratio between Eosin Y and TS-1 zeolite is 7 and 1/8, respectively. In the presence of triethanolamine (TEA) as an electron donor, the highest rate of hydrogen generation and apparent quantum efficiency are 34 μmol h -1 and 9.4%, respectively, under visible light irradiation (λ ≥ 420 nm). Short-term stability test indicates that the catalyst is rather stable during 50 h photoreaction

  8. Photocatalytic hydrogen generation over Eosin Y-Sensitized TS-1 zeolite

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Xiaojie [State Key Laboratory for Oxo Synthesis and Selective Oxidation, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Tianshui Zhong Road 18, Lanzhou 730000 (China); Graduate University of the Chinese Academy of Sciences, Beijing 100101 (China); Jin Zhiliang [State Key Laboratory for Oxo Synthesis and Selective Oxidation, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Tianshui Zhong Road 18, Lanzhou 730000 (China); Li Yuexiang [Department of Chemistry, Nanchang University, Nanjing Road 245, Nanchang 330047 (China); Li Shuben [State Key Laboratory for Oxo Synthesis and Selective Oxidation, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Tianshui Zhong Road 18, Lanzhou 730000 (China); Lu Gongxuan [State Key Laboratory for Oxo Synthesis and Selective Oxidation, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Tianshui Zhong Road 18, Lanzhou 730000 (China)], E-mail: gxlu@lzb.ac.cn

    2008-05-30

    Eosin Y-sensitized TS-1 zeolite was studied for the photo-reduction of water into hydrogen driven by visible light ({lambda} {>=} 420 nm). The optimal pH and weight ratio between Eosin Y and TS-1 zeolite is 7 and 1/8, respectively. In the presence of triethanolamine (TEA) as an electron donor, the highest rate of hydrogen generation and apparent quantum efficiency are 34 {mu}mol h{sup -1} and 9.4%, respectively, under visible light irradiation ({lambda} {>=} 420 nm). Short-term stability test indicates that the catalyst is rather stable during 50 h photoreaction.

  9. Hydrogen storage by carbon materials synthesized from oil seeds and fibrous plant materials

    Energy Technology Data Exchange (ETDEWEB)

    Sharon, Maheshwar; Bhardwaj, Sunil; Jaybhaye, Sandesh [Nanotechnology Research Center, Birla College, Kalyan 421304 (India); Soga, T.; Afre, Rakesh [Graduate School of Engineering, Nagoya Institute of Technology, Nagoya (Japan); Sathiyamoorthy, D.; Dasgupta, K. [Powder Metallurgy Division, BARC, Trombay 400 085 (India); Sharon, Madhuri [Monad Nanotech Pvt. Ltd., A702 Bhawani Tower, Powai, Mumbai 400 076 (India)

    2007-12-15

    Carbon materials of various morphologies have been synthesized by pyrolysis of various oil-seeds and plant's fibrous materials. These materials are characterized by SEM and Raman. Surface areas of these materials are determined by methylene blue method. These carbon porous materials are used for hydrogen storage. Carbon fibers with channel type structure are obtained from baggas and coconut fibers. It is reported that amongst the different plant based precursors studied, carbon from soyabean (1.09 wt%) and baggas (2.05 wt%) gave the better capacity to store hydrogen at 11kg/m{sup 2} pressure of hydrogen at room temperature. Efforts are made to correlate the hydrogen adsorption capacity with intensities and peak positions of G- and D-band obtained with carbon materials synthesized from plant based precursors. It is suggested that carbon materials whose G-band is around 1575cm{sup -1} and the intensity of D-band is less compared to G-band, may be useful material for hydrogen adsorption study. (author)

  10. Biological methanation of hydrogen within biogas plants: A model-based feasibility study

    International Nuclear Information System (INIS)

    Bensmann, A.; Hanke-Rauschenbach, R.; Heyer, R.; Kohrs, F.; Benndorf, D.; Reichl, U.; Sundmacher, K.

    2014-01-01

    Highlights: • Simulation study about direct methanation of hydrogen within biogas plants. • In stationary operation two limitations, namely biological and transfer limit. • Biological limit at 4m H2 3 /m CO2 3 due to stoichiometry. • Dynamic behaviour shows three qualitatively different step responses. • A simple control scheme to meet the output quality was developed. - Abstract: One option to utilize excess electric energy is its conversion to hydrogen and the subsequent methanation. An alternative to the classical chemical Sabatier process is the biological methanation (methanogenesis) within biogas plants. In conventional biogas plants methane and carbon dioxide is produced. The latter can be directly converted to methane by feeding hydrogen into the reactor, since hydrogenotrophic bacteria are present. In the present contribution, a comprehensive simulation study with respect to stationary operating conditions and disturbances is presented. It reveals two qualitative different limitations, namely a biological limit (appr. at 4m H2 3 /m CO2 3 corresponds to 4.2m H2,STP 3 /m liq 3 /d) as well as a transfer limit. A parameter region for a safe operation was defined. The temporary operation with stationary unfeasible conditions was analysed and thereby three qualitatively different disturbances can be distinguished. In one of these the operation for several days is possible. On the basis of these results, a controller was proposed and tested that meets the demands on the conversion of hydrogen and also prevents the washout of the microbial community due to hydrogen overload

  11. Microbiome Selection Could Spur Next-Generation Plant Breeding Strategies.

    Science.gov (United States)

    Gopal, Murali; Gupta, Alka

    2016-01-01

    " No plant is an island too …" Plants, though sessile, have developed a unique strategy to counter biotic and abiotic stresses by symbiotically co-evolving with microorganisms and tapping into their genome for this purpose. Soil is the bank of microbial diversity from which a plant selectively sources its microbiome to suit its needs. Besides soil, seeds, which carry the genetic blueprint of plants during trans-generational propagation, are home to diverse microbiota that acts as the principal source of microbial inoculum in crop cultivation. Overall, a plant is ensconced both on the outside and inside with a diverse assemblage of microbiota. Together, the plant genome and the genes of the microbiota that the plant harbors in different plant tissues, i.e., the 'plant microbiome,' form the holobiome which is now considered as unit of selection: 'the holobiont.' The 'plant microbiome' not only helps plants to remain fit but also offers critical genetic variability, hitherto, not employed in the breeding strategy by plant breeders, who traditionally have exploited the genetic variability of the host for developing high yielding or disease tolerant or drought resistant varieties. This fresh knowledge of the microbiome, particularly of the rhizosphere, offering genetic variability to plants, opens up new horizons for breeding that could usher in cultivation of next-generation crops depending less on inorganic inputs, resistant to insect pest and diseases and resilient to climatic perturbations. We surmise, from ever increasing evidences, that plants and their microbial symbionts need to be co-propagated as life-long partners in future strategies for plant breeding. In this perspective, we propose bottom-up approach to co-propagate the co-evolved, the plant along with the target microbiome, through - (i) reciprocal soil transplantation method, or (ii) artificial ecosystem selection method of synthetic microbiome inocula, or (iii) by exploration of microRNA transfer

  12. A third-generation dispersion and third-generation hydrogen bonding corrected PM6 method

    DEFF Research Database (Denmark)

    Kromann, Jimmy Charnley; Christensen, Anders Steen; Svendsen, Casper Steinmann

    2014-01-01

    We present new dispersion and hydrogen bond corrections to the PM6 method, PM6-D3H+, and its implementation in the GAMESS program. The method combines the DFT-D3 dispersion correction by Grimme et al. with a modified version of the H+ hydrogen bond correction by Korth. Overall, the interaction...... in GAMESS, while the corresponding numbers for PM6-DH+ implemented in MOPAC are 54, 17, 15, and 2. The PM6-D3H+ method as implemented in GAMESS offers an attractive alternative to PM6-DH+ in MOPAC in cases where the LBFGS optimizer must be used and a vibrational analysis is needed, e.g., when computing...... vibrational free energies. While the GAMESS implementation is up to 10 times slower for geometry optimizations of proteins in bulk solvent, compared to MOPAC, it is sufficiently fast to make geometry optimizations of small proteins practically feasible....

  13. Strain measurements of nuclear power plant steam generator antiseismic supports

    International Nuclear Information System (INIS)

    Kulichevsky, R.

    1997-01-01

    The nuclear power plants steam generators have different types of structural supports. One of these types are the antiseismic supports, which are intended to be under stress only if a seismic event takes place. Nevertheless, the antiseismic supports lugs, that are welded to the steam generator vessel, are subjected to thermal fatigue because of the temperature cycles related with the shut down and start up operations performed during the life of the nuclear power plant. In order to evaluate the stresses that the lugs are subjected to, several strain gages were welded on two supports lugs, positioned at two heights of one of the Embalse nuclear power plant steam generators. In this paper, the instrumentation used and the strain measurements obtained during two start up operations are presented. The influence of the plant start up operation parameters on the lugs strain evolution is also analyzed. (author) [es

  14. Carbon-supported cobalt catalyst for hydrogen generation from alkaline sodium borohydride solution

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Dongyan; Liu, Xinmin; Cao, Changqing; Guo, Qingjie [College of Chemical Engineering, Qingdao University of Science and Technology, Qingdao 266042 (China); Dai, Ping [College of Electromechanical Engineering, Qingdao University of Science and Technology, Qingdao 266061 (China)

    2008-08-01

    Low cost transition metal catalysts with high performance are attractive for the development of on-board hydrogen generation systems by catalytic hydrolysis of sodium borohydride (NaBH{sub 4}) in fuel cell fields. In this study, hydrogen production from alkaline NaBH{sub 4} via hydrolysis process over carbon-supported cobalt catalysts was studied. The catalytic activity of the supported cobalt catalyst was found to be highly dependent on the calcination temperatures. The hydrogen generation rate increases with calcination temperatures in the range of 200-400 C, but a high calcination temperature above 500 C led to markedly decreased activity. X-ray diffraction patterns reveal that the catalysts experience phase transition from amorphous Co-B to crystalline cobalt hydroxide with increase in calcination temperatures. The reaction performance is also dependent on the concentration of NaBH{sub 4}, and the hydrogen generation rate increases for lower NaBH{sub 4} concentrations and decreases after reaching a maximum at 10 wt.% of NaBH{sub 4}. (author)

  15. Comparative study of the hydrogen generation during short term station blackout (STSBO) in a BWR

    International Nuclear Information System (INIS)

    Polo-Labarrios, M.A.; Espinosa-Paredes, G.

    2015-01-01

    Highlights: • Comparative study of generation in a simulated STSBO severe accident. • MELCOR and SCDAP/RELAP5 codes were used to understanding the main phenomena. • Both codes present similar thermal-hydraulic behavior for pressure and boil off. • SCDAP/RELAP5 predicts 15.8% lower hydrogen production than MELCOR. - Abstract: The aim of this work is the comparative study of hydrogen generation and the associated parameters in a simulated severe accident of a short-term station blackout (STSBO) in a typical BWR-5 with Mark-II containment. MELCOR (v.1.8.6) and SCDAP/RELAP5 (Mod.3.4) codes were used to understand the main phenomena in the STSBO event through the results comparison obtained from simulations with these codes. Due that the simulation scope of SCDAP/RELAP5 is limited to failure of the vessel pressure boundary, the comparison was focused on in-vessel severe accident phenomena; with a special interest in the vessel pressure, boil of cooling, core temperature, and hydrogen generation. The results show that at the beginning of the scenario, both codes present similar thermal-hydraulic behavior for pressure and boil off of cooling, but during the relocation, the pressure and boil off, present differences in timing and order of magnitude. Both codes predict in similar time the beginning of melting material drop to the lower head. As far as the hydrogen production rate, SCDAP/RELAP5 predicts 15.8% lower production than MELCOR

  16. Ultra slow muon generation and thermionic emission of hydrogen isotopes from tungsten surface

    International Nuclear Information System (INIS)

    Miyake, Yasuhiro

    2000-01-01

    To generate ultra slow muon, we developed Lyman α light (Lα light) resonance ionization method using 1s-2p-unbound transition. By this method, the desorption process of hydrogen isotope and hydrogen atom generation were studied. In order to generate T atom, the laser resonance ionization of hydrogen nucleus was investigated. When wavelength of VUV light was fixed to 121.52 nm, 1s-2p resonance frequency of T, and VUV light agreed with 355 nm ionization laser in space and time, promising event was observed. The fact showed the resonance ionization method could isolate and detect T atom. By the same method, the experiment of H and D atom were carried out under the condition of the same wavelength of VUV light of 121.57 and 121.53 nm of Lα light, respectively, and the same results were obtained. On the Mu resonance ionization experiment, the light wavelength of VUV was 122.09 nm of Lα of muonium. The results showed the promising event was observed on the expected position of TOF and Mass. The resonance ionization method using Lα light of hydrogen isotope on tungsten film is a very useful method to separate Mu, H, D and T under the same experiment conditions without wavelength of VUV light. (S.Y.)

  17. Modeling of hydrogen/deuterium dynamics and heat generation on palladium nanoparticles for hydrogen storage and solid-state nuclear fusion

    Directory of Open Access Journals (Sweden)

    Katsuaki Tanabe

    2016-01-01

    Full Text Available We modeled the dynamics of hydrogen and deuterium adsorbed on palladium nanoparticles including the heat generation induced by the chemical adsorption and desorption, as well as palladium-catalyzed reactions. Our calculations based on the proposed model reproduce the experimental time-evolution of pressure and temperature with a single set of fitting parameters for hydrogen and deuterium injection. The model we generated with a highly generalized set of formulations can be applied for any combination of a gas species and a catalytic adsorbent/absorbent. Our model can be used as a basis for future research into hydrogen storage and solid-state nuclear fusion technologies.

  18. Modeling of hydrogen/deuterium dynamics and heat generation on palladium nanoparticles for hydrogen storage and solid-state nuclear fusion.

    Science.gov (United States)

    Tanabe, Katsuaki

    2016-01-01

    We modeled the dynamics of hydrogen and deuterium adsorbed on palladium nanoparticles including the heat generation induced by the chemical adsorption and desorption, as well as palladium-catalyzed reactions. Our calculations based on the proposed model reproduce the experimental time-evolution of pressure and temperature with a single set of fitting parameters for hydrogen and deuterium injection. The model we generated with a highly generalized set of formulations can be applied for any combination of a gas species and a catalytic adsorbent/absorbent. Our model can be used as a basis for future research into hydrogen storage and solid-state nuclear fusion technologies.

  19. Some environmental effects of emissions from CANDU nuclear generating stations and heavy water plants

    International Nuclear Information System (INIS)

    Effer, W.R.

    Non-radioactive releases during normal operation of Ontario Hydro's nuclear generating stations and heavy water plants are summarized and related to existing regulations and guidelines. Low-grade heat in the circulating cooling water discharge is the most important of the non-radioactive effluents. Some of the hydrological, biological and water quality aspects of thermal discharges are discussed in relation to the operation of Ontario Hydro's thermal generating stations on the Great Lakes. Chemical releases to air or water include chlorine, hydrogen sulphide, water treatment plant effluents, oily waste water and sewage lagoon effluents. The significance of the first two of these releases to the environment is reviewed, particularly in relation to Great Lakes water quality and biological concerns. (author)

  20. Large area imaging of hydrogenous materials using fast neutrons from a DD fusion generator

    Energy Technology Data Exchange (ETDEWEB)

    Cremer, J.T., E-mail: ted@adelphitech.com [Adelphi Technology Inc., 2003 East Bayshore Road, Redwood City, California 94063 (United States); Williams, D.L.; Gary, C.K.; Piestrup, M.A.; Faber, D.R.; Fuller, M.J.; Vainionpaa, J.H.; Apodaca, M. [Adelphi Technology Inc., 2003 East Bayshore Road, Redwood City, California 94063 (United States); Pantell, R.H.; Feinstein, J. [Department of Electrical Engineering, Stanford University, Stanford, California 94305 (United States)

    2012-05-21

    A small-laboratory fast-neutron generator and a large area detector were used to image hydrogen-bearing materials. The overall image resolution of 2.5 mm was determined by a knife-edge measurement. Contact images of objects were obtained in 5-50 min exposures by placing them close to a plastic scintillator at distances of 1.5 to 3.2 m from the neutron source. The generator produces 10{sup 9} n/s from the DD fusion reaction at a small target. The combination of the DD-fusion generator and electronic camera permits both small laboratory and field-portable imaging of hydrogen-rich materials embedded in high density materials.

  1. Thermodynamic analysis of a solar-based multi-generation system with hydrogen production

    International Nuclear Information System (INIS)

    Ozturk, Murat; Dincer, Ibrahim

    2013-01-01

    Thermodynamic analysis of a renewable-based multi-generation energy production system which produces a number of outputs, such as power, heating, cooling, hot water, hydrogen and oxygen is conducted. This solar-based multi-generation system consists of four main sub-systems: Rankine cycle, organic Rankine cycle, absorption cooling and heating, and hydrogen production and utilization. Exergy destruction ratios and rates, power or heat transfer rates, energy and exergy efficiencies of the system components are carried out. Some parametric studies are performed in order to examine the effects of varying operating conditions (e.g., reference temperature, direct solar radiation and receiver temperature) on the exergy efficiencies of the sub-systems as well as the whole system. The solar-based multi-generation system which has an exergy efficiency of 57.35%, is obtained to be higher than using these sub-systems separately. The evaluation of the exergy efficiency and exergy destruction for the sub-systems and the overall system show that the parabolic dish collectors have the highest exergy destruction rate among constituent parts of the solar-based multi-generation system, due to high temperature difference between the working fluid and collector receivers. -- Highlights: ► Development of a new multi-generation system for solar-based hydrogen production. ► Investigation of exergy efficiencies and destructions in each process of the system. ► Evaluation of varying operating conditions on the exergy destruction and efficiency

  2. Hydrogen generation from hydrolysis of sodium borohydride using Ru(0) nanoclusters as catalyst

    International Nuclear Information System (INIS)

    Ozkar, S.; Zahmakiran, M.

    2005-01-01

    Sodium borohydride is stable in aqueous alkaline solution, however, it hydrolyses in water to hydrogen gas in the presence of suitable catalyst. By this way hydrogen can be generated safely for the fuel cells. Generating H 2 catalytically from NaBH 4 solutions has many advantages: NaBH 4 solutions are nonflammable, reaction products are environmentally benign, rate of H 2 generation is easily controlled, the reaction product NaBO 2 can be recycled, H 2 can be generated even at low temperatures. All of the catalysts that has been used in hydrolysis of sodium borohydride are bulk metals and they act as heterogeneous catalysts. The limited surface area of the heterogeneous catalysts causes lower catalytic activity as the activity of catalyst is directly related to its surface area. Thus, the use of metal nanoparticles with large surface area provides potential route to increase the catalytic activity. Here, we report, for the first time, the use of ruthenium(0) nanoclusters as catalyst in the hydrolysis of sodium borohydride liberating hydrogen gas. The ruthenium nanoparticles are generated from the reduction of ruthenium(III) chloride by sodium borohydride in water and stabilized by specific ligand. The ruthenium(0) nanoclusters are found to be highly active catalyst for the hydrolysis of sodium borohydride

  3. Alkali free hydrolysis of sodium borohydride for hydrogen generation under pressure

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira, M.J.F.; Pinto, A.M.F.R. [Centro de Estudos de Fenomenos de Transporte, Departamento de Engenharia Quimica, Faculdade de Engenharia da Universidade do Porto, Rua Dr. Roberto Frias s/n, 4200-465 Porto (Portugal); Gales, L. [Instituto de Biologia Molecular e Celular, Universidade do Porto, Rua do Campo Alegre 823, 4150-180 Porto and Instituto de Ciencias Biomedicas Abel Salazar, Largo Prof. Abel Salazar 2, 4099-003 Porto (Portugal); Fernandes, V.R.; Rangel, C.M. [Laboratorio Nacional de Energia e Geologia - LNEG, Fuel Cells and Hydrogen Unit Estrada do Paco do Lumiar 22, 1649-038 Lisboa (Portugal)

    2010-09-15

    The present study is related with the production of hydrogen gas (H{sub 2}), at elevated pressures and with high gravimetric storage density, to supply a PEM fuel cell on-demand. To achieve this goal, solid sodium borohydride (NaBH{sub 4}) was mixed with a proper amount of a powder reused nickel-ruthenium based catalyst (Ni-Ru based/NaBH{sub 4}: 0.2 and 0.4 g/g; {approx}150 times reused) inside the bottom of a batch reactor. Then, a stoichiometric amount of pure liquid water (H{sub 2}O/NaBH{sub 4}: 2-8 mol/mol) was added and the catalyzed NaBH{sub 4} hydrolysis evolved, in the absence of an alkali inhibitor. In this way, this research work is designated alkali free hydrolysis of NaBH{sub 4} for H{sub 2} generation. This type of hydrolysis is excellent from an environmental point of view because it does not involve strongly caustic solutions. Experiments were performed in three batch reactors with internal volumes 646, 369 and 229 cm{sup 3}, and having different bottom geometries (flat and conical shapes). The H{sub 2} generated was a function of the added water and completion was achieved with H{sub 2}O/NaBH{sub 4} = 8 mol/mol. The results show that hydrogen yields and rates increase remarkably increasing both system temperature and pressure. Reactor bottom shape influences deeply H{sub 2} generation: the conical bottom shape greatly enhances the rate and practically eliminates the reaction induction time. Our system of compressed hydrogen generation up to 1.26 MPa shows 6.3 wt% and 70 kg m{sup -3}, respectively, for gravimetric and volumetric hydrogen storage capacities (materials-only basis) and therefore is a viable hydrogen storage candidate for portable applications. (author)

  4. Stand alone solution for generation and storage of hydrogen and electric energy

    International Nuclear Information System (INIS)

    Gany, Alon; Elitzur, Shani; Valery

    2015-01-01

    A novel method enabling safe, simple, and controllable production, storage, and use of hydrogen as well as compact electric energy storage and generation via hydrogen- oxygen fuel cells has been developed. The technology indicates, in our opinion, a significant milestone in the search for practical utilization of hydrogen as an alternative energy source. It consists of an original thermal-chemical treatment / activation of aluminum powders to react spontaneously with water to produce hydrogen at regular conditions according to the reaction Al+3H 2 O=Al (OH) 3 +3/2H 2 . Only about 1-2% of lithium, based activator is applied, and any type of water including tap water, sea water and waste water may be used, making the method attractive for variety of applications. 11% of hydrogen compared to the aluminum mass can be obtained, and our experiments reveal 90% reaction yield and more. The technology has a clear advantage over batteries, providing specific electric energy of over 2 kW h/kg Al, 5-10 times greater than that of commonly used lithium-ion batteries. Combined with a fuel cell it may be particularly beneficial for stand-alone electric power generators, where there is no access to the grid. Such applications include emergency generators (e.g., in hospitals), electricity backup systems, and power generation in remote communication posts. Automotive applications may be considered as well. The technology provides green electric energy and quiet operation as well as additional heat energy resulting mainly from the exothermic aluminum-water reaction. (full text)

  5. Design consideration on hydrogen production demonstration plant of thermochemical IS process

    International Nuclear Information System (INIS)

    Iwatsuki, Jin; Noguchi, Hiroki; Terada, Atsuhiko; Kubo, Shinji; Sakaba, Nariaki; Onuki, Kaoru; Hino, Ryutaro

    2009-03-01

    Preliminary design study was carried out on the hydrogen production demonstration plant of thermochemical IS process. In the pilot test, hydrogen production will be examined under prototypical condition using an apparatus made of industrial materials, which is driven by the sensible heat of helium gas heated by an electric heater that simulates the High Temperature Engineering Test Reactor (HTTR). Tentative system condition was defined considering the HTTR specification and the experience on the construction and the operation of the mock-up test facility using methane reforming for hydrogen production. The process condition and the system flow diagram were discussed to meet the system condition. Based on the defined process condition, types of the main components were discussed taking the corrosion resistance of the structural materials into consideration. Applicable rules and regulations were also surveyed regarding the plant construction and operation. (author)

  6. Hydrogen Generation by Koh-Ethanol Plasma Electrolysis Using Double Compartement Reactor

    Science.gov (United States)

    Saksono, Nelson; Sasiang, Johannes; Dewi Rosalina, Chandra; Budikania, Trisutanti

    2018-03-01

    This study has successfully investigated the generation of hydrogen using double compartment reactor with plasma electrolysis process. Double compartment reactor is designed to achieve high discharged voltage, high concentration, and also reduce the energy consumption. The experimental results showed the use of double compartment reactor increased the productivity ratio 90 times higher compared to Faraday electrolysis process. The highest hydrogen production obtained is 26.50 mmol/min while the energy consumption can reach up 1.71 kJ/mmol H2 at 0.01 M KOH solution. It was shown that KOH concentration, addition of ethanol, cathode depth, and temperature have important effects on hydrogen production, energy consumption, and process efficiency.

  7. Preliminary materials selection issues for the next generation nuclear plant reactor pressure vessel.

    Energy Technology Data Exchange (ETDEWEB)

    Natesan, K.; Majumdar, S.; Shankar, P. S.; Shah, V. N.; Nuclear Engineering Division

    2007-03-21

    In the coming decades, the United States and the entire world will need energy supplies to meet the growing demands due to population increase and increase in consumption due to global industrialization. One of the reactor system concepts, the Very High Temperature Reactor (VHTR), with helium as the coolant, has been identified as uniquely suited for producing hydrogen without consumption of fossil fuels or the emission of greenhouse gases [Generation IV 2002]. The U.S. Department of Energy (DOE) has selected this system for the Next Generation Nuclear Plant (NGNP) Project, to demonstrate emissions-free nuclear-assisted electricity and hydrogen production within the next 15 years. The NGNP reference concepts are helium-cooled, graphite-moderated, thermal neutron spectrum reactors with a design goal outlet helium temperature of {approx}1000 C [MacDonald et al. 2004]. The reactor core could be either a prismatic graphite block type core or a pebble bed core. The use of molten salt coolant, especially for the transfer of heat to hydrogen production, is also being considered. The NGNP is expected to produce both electricity and hydrogen. The process heat for hydrogen production will be transferred to the hydrogen plant through an intermediate heat exchanger (IHX). The basic technology for the NGNP has been established in the former high temperature gas reactor (HTGR) and demonstration plants (DRAGON, Peach Bottom, AVR, Fort St. Vrain, and THTR). In addition, the technologies for the NGNP are being advanced in the Gas Turbine-Modular Helium Reactor (GT-MHR) project, and the South African state utility ESKOM-sponsored project to develop the Pebble Bed Modular Reactor (PBMR). Furthermore, the Japanese HTTR and Chinese HTR-10 test reactors are demonstrating the feasibility of some of the planned components and materials. The proposed high operating temperatures in the VHTR place significant constraints on the choice of material selected for the reactor pressure vessel for

  8. 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

  9. Development of a low-cost oxy-hydrogen bio-fuel cell for generation of electricity using Nostoc as a source of hydrogen

    Energy Technology Data Exchange (ETDEWEB)

    Sangeeta Dawar; Behera, B.K. [Maharshi Dayanand University, Rohtak (India). Dept. of Biosciences; Prasanna Mohanty [Jawaharlal Nehru University, New Delhi (India). School of Life Sciences

    1998-10-10

    An oxy-hydrogen bio-fuel cell, based on a carbon-carbon electrode has been fabricated. The electrode pellets were prepared by taking carbon powder mixed with polyvinylalcohol as a binder. The anode was charged with Co-Al spinel mixed oxide at 700{sup o}C, 30% KOH acted as an electrolyte. For the cyanobacterial bioreactor, a potential heterocystous blue green alga of Nostoc spp. has been used for hydrogen production and electrical energy generation. Various nutrient enrichment techniques are employed to increase the hydrogen generation efficiency of the algae. One litre free cell algal reactor attached to the fuel cell, at the anode end for hydrogen gas input, generated about 300 mV of voltage and 100 mA of current. Our present findings on the development of a low cost fuel cell with high efficiency of current output may be helpful in commercializing this technology. (author)

  10. Ratio of tritiated water and hydrogen generated in mercury through a nuclear reaction

    Energy Technology Data Exchange (ETDEWEB)

    Manabe, K. [Nuclear Science and Engineering Directorate, Japan Atomic Energy Agency (JAEA), Tokai, Naka-gun, Ibaraki 319-1195 (Japan)], E-mail: manabe.kentaro@jaea.go.jp; Yokoyama, S. [Nuclear Science and Engineering Directorate, Japan Atomic Energy Agency (JAEA), Tokai, Naka-gun, Ibaraki 319-1195 (Japan)

    2008-02-15

    Tritium generated in a mercury target is a source of potential exposure of personnel at high-energy accelerator facilities. Knowledge of the chemical form of tritium is necessary to estimate the internal doses. We studied the tritium generation upon thermal neutron irradiation of a mercury target modified into liquid lithium amalgam to examine the ratio of tritiated water ([{sup 3}H]H{sub 2}O) and tritiated hydrogen ([{sup 3}H]H{sub 2}). The ratio between [{sup 3}H]H{sub 2}O and [{sup 3}H]H{sub 2} generated in lithium amalgam was 4:6 under these experimental conditions.

  11. The Effect of Herbicides on Hydrogen Peroxide Generation in Isolated Vacuoles of Red Beet Root (Beta vulgaris L.

    Directory of Open Access Journals (Sweden)

    E.V. Pradedova

    2015-12-01

    Full Text Available Influence of herbicides on the hydrogen peroxide generation in vacuolar extracts of red beet root (Beta vulgaris L. was investigated. Belonging to different chemical classes of herbicide compounds have been used. Herbicides differ from each other in the mechanism of effects on plants. Clopyralid (aromatic acid herbicide, derivative of picolinic acid and 2.4-D (phenoxyacetic herbicide, characterized by hormone-like effects, contributed to the formation of H2O2 in vacuolar extracts. Fluorodifen (nitrophenyl ether herbicide and diuron (urea herbicide also have increased contents H2O2. These compounds inhibit the electron transport, photosynthesis, and photorespiration in sensitive plants. Herbicidal effect of glyphosate (organophosphorus herbicide is due to the inhibition of amino acid synthesis in plant cells. Glyphosate did not affect the content of H2O2 in vacuolar extracts. Herbicide dependent H2O2-generation did not occur with oxidoreductase inhibitors, potassium cyanide and sodium azide. The results suggest that the formation of ROS in the vacuoles due to activity of oxidoreductases, which could interact with herbicides.

  12. Advanced chemical hydride-based hydrogen generation/storage system for fuel cell vehicles

    Energy Technology Data Exchange (ETDEWEB)

    Breault, R.W.; Rolfe, J. [Thermo Power Corp., Waltham, MA (United States)

    1998-08-01

    Because of the inherent advantages of high efficiency, environmental acceptability, and high modularity, fuel cells are potentially attractive power supplies. Worldwide concerns over clean environments have revitalized research efforts on developing fuel cell vehicles (FCV). As a result of intensive research efforts, most of the subsystem technology for FCV`s are currently well established. These include: high power density PEM fuel cells, control systems, thermal management technology, and secondary power sources for hybrid operation. For mobile applications, however, supply of hydrogen or fuel for fuel cell operation poses a significant logistic problem. To supply high purity hydrogen for FCV operation, Thermo Power`s Advanced Technology Group is developing an advanced hydrogen storage technology. In this approach, a metal hydride/organic slurry is used as the hydrogen carrier and storage media. At the point of use, high purity hydrogen will be produced by reacting the metal hydride/organic slurry with water. In addition, Thermo Power has conceived the paths for recovery and regeneration of the spent hydride (practically metal hydroxide). The fluid-like nature of the spent hydride/organic slurry will provide a unique opportunity for pumping, transporting, and storing these materials. The final product of the program will be a user-friendly and relatively high energy storage density hydrogen supply system for fuel cell operation. In addition, the spent hydride can relatively easily be collected at the pumping station and regenerated utilizing renewable sources, such as biomass, natural, or coal, at the central processing plants. Therefore, the entire process will be economically favorable and environmentally friendly.

  13. Preliminary analysis of an hydrogen generator system based on nuclear energy in the Laguna Verde site

    International Nuclear Information System (INIS)

    Flores y Flores, A.; Francois L, J.L.

    2003-01-01

    The shortage of fossil fuels in the next future, as well as the growing one demand of energetics and the high cost of the production of alternating fuels, it forces us to take advantage of to the maximum the fossil fuel with the one which we count and to look for the form of producing alternating fuels at a low cost and better even if these supply sources are reliable and non pollutants. It is intended a solution to the shortage of fuel; to use the thermal energy liberated of some appropriate nuclear reactor to be able to obtain a fuel but clean and relatively cheap as it is the hydrogen. In the first place the methods were looked for to produce hydrogen using thermal energy, later it was analyzed the temperature liberated by the existent nuclear reactors as well as the advanced designs, according to this liberated temperature settled down that the methods but feasible to produce hydrogen its were the one of reformed with water stream of the natural gas (methane) and the other one of the S-I thermochemical cycle, and the nuclear reactors that give the thermal energy for this production they are those of gas of high temperature. Once established the processes and the appropriate reactors, it was analyzed the site of Laguna Verde, with relationship to the free space to be able to place the reactor and the plant producer of hydrogen, as well as the direction in which blow the dominant winds and the near towns to the place, it was carried out an analysis of some explosion of tanks that could store hydrogen and the damage that its could to cause depending from the distance to which its were of the fire. Finally it was carried out an evaluation of capital and of operation costs for those two methods of hydrogen production. (Author)

  14. Photocatalytic hydrogen generation from water under visible light using core/shell nano-catalysts.

    Science.gov (United States)

    Wang, X; Shih, K; Li, X Y

    2010-01-01

    A microemulsion technique was employed to synthesize nano-sized photocatalysts with a core (CdS)/shell (ZnS) structure. The primary particles of the photocatalysts were around 10 nm, and the mean size of the catalyst clusters in water was about 100 nm. The band gaps of the catalysts ranged from 2.25 to 2.46 eV. The experiments of photocatalytic H(2) generation showed that the catalysts (CdS)(x)/(ZnS)(1-x) with x ranging from 0.1 to 1 were able to produce hydrogen from water photolysis under visible light. The catalyst with x=0.9 had the highest rate of hydrogen production. The catalyst loading density also influenced the photo-hydrogen production rate, and the best catalyst concentration in water was 1 g L(-1). The stability of the nano-catalysts in terms of size, morphology and activity was satisfactory during an extended test period for a specific hydrogen production rate of 2.38 mmol g(-1) L(-1) h(-1) and a quantum yield of 16.1% under visible light (165 W Xe lamp, lambda>420 nm). The results demonstrate that the (CdS)/(ZnS) core/shell nano-particles are a novel photo-catalyst for renewable hydrogen generation from water under visible light. This is attributable to the large band-gap ZnS shell that separates the electron/hole pairs generated by the CdS core and hence reduces their recombinations.

  15. Hydrogen generation from deliquescence of ammonia borane using Ni-Co/r-GO catalyst

    Science.gov (United States)

    Chou, Chang-Chen; Chen, Bing-Hung

    2015-10-01

    Hydrogen generation from the catalyzed deliquescence/hydrolysis of ammonia borane (AB) using the Ni-Co catalyst supported on the graphene oxide (Ni-Co/r-GO catalyst) under the conditions of limited water supply was studied with the molar feed ratio of water to ammonia borane (denoted as H2O/AB) at 2.02, 3.97 and 5.93, respectively. The conversion efficiency of ammonia borane to hydrogen was estimated both from the cumulative volume of the hydrogen gas generated and the conversion of boron chemistry in the hydrolysates analyzed by the solid-state 11B NMR. The conversion efficiency of ammonia borane could reach nearly 100% under excess water dosage, that is, H2O/AB = 3.97 and 5.93. Notably, the hydrogen storage capacity could reach as high as 6.5 wt.% in the case with H2O/AB = 2.02. The hydrolysates of ammonia borane in the presence of Ni-Co/r-GO catalyst were mainly the mixture of boric acid and metaborate according to XRD, FT-IR and solid-state 11B NMR analyses.

  16. Rapid hydrogen gas generation using reactive thermal decomposition of uranium hydride.

    Energy Technology Data Exchange (ETDEWEB)

    Kanouff, Michael P.; Van Blarigan, Peter; Robinson, David B.; Shugard, Andrew D.; Gharagozloo, Patricia E.; Buffleben, George M.; James, Scott Carlton; Mills, Bernice E.

    2011-09-01

    Oxygen gas injection has been studied as one method for rapidly generating hydrogen gas from a uranium hydride storage system. Small scale reactors, 2.9 g UH{sub 3}, were used to study the process experimentally. Complimentary numerical simulations were used to better characterize and understand the strongly coupled chemical and thermal transport processes controlling hydrogen gas liberation. The results indicate that UH{sub 3} and O{sub 2} are sufficiently reactive to enable a well designed system to release gram quantities of hydrogen in {approx} 2 seconds over a broad temperature range. The major system-design challenge appears to be heat management. In addition to the oxidation tests, H/D isotope exchange experiments were performed. The rate limiting step in the overall gas-to-particle exchange process was found to be hydrogen diffusion in the {approx}0.5 {mu}m hydride particles. The experiments generated a set of high quality experimental data; from which effective intra-particle diffusion coefficients can be inferred.

  17. Hydrogen generation from water using Mg nanopowder produced by arc plasma method

    Directory of Open Access Journals (Sweden)

    Masahiro Uda, Hideo Okuyama, Tohru S Suzuki and Yoshio Sakka

    2012-01-01

    Full Text Available We report that hydrogen gas can be easily produced from water at room temperature using a Mg nanopowder (30–1000 nm particles, average diameter 265 nm. The Mg nanopowder was produced by dc arc melting of a Mg ingot in a chamber with mixed-gas atmosphere (20% N2–80% Ar at 0.1 MPa using custom-built nanopowder production equipment. The Mg nanopowder was passivated with a gas mixture of 1% O2 in Ar for 12 h in the final step of the synthesis, after which the nanopowder could be safely handled in ambient air. The nanopowder vigorously reacted with water at room temperature, producing 110 ml of hydrogen gas per 1 g of powder in 600 s. This amount corresponds to 11% of the hydrogen that could be generated by the stoichiometric reaction between Mg and water. Mg(OH2 flakes formed on the surface of the Mg particles as a result of this reaction. They easily peeled off, and the generation of hydrogen continued until all the Mg was consumed.

  18. Multi-purpose hydrogen isotopes separation plant design

    Energy Technology Data Exchange (ETDEWEB)

    Boniface, H.A.; Gnanapragasam, N.V.; Ryland, D.K.; Suppiah, S.; Castillo, I. [Atomic Energy of Canada Limited - AECL, Chalk River, ON (Canada)

    2015-03-15

    There is a potential interest at AECL's Chalk River Laboratories to remove tritium from moderately tritiated light water and to reclaim tritiated, downgraded heavy water. With only a few limitations, a single CECE (Combined Electrolysis and Catalytic Exchange) process configuration can be designed to remove tritium from heavy water or light water and upgrade heavy water. Such a design would have some restrictions on the nature of the feed-stock and tritium product, but could produce essentially tritium-free light or heavy water that is chemically pure. The extracted tritium is produced as a small quantity of tritiated heavy water. The overall plant capacity is fixed by the total amount of electrolysis and volume of catalyst. In this proposal, with 60 kA of electrolysis a throughput of 15 kg*h{sup -1} light water for detritiation, about 4 kg*h{sup -1} of heavy water for detritiation and about 27 kg*h{sup -1} of 98% heavy water for upgrading can be processed. Such a plant requires about 1,000 liters of AECL isotope exchange catalyst. The general design features and details of this multi-purpose CECE process are described in this paper, based on some practical choices of design criteria. In addition, we outline the small differences that must be accommodated and some compromises that must be made to make the plant capable of such flexible operation. (authors)

  19. Co-generation of hydrogen from nuclear and wind: the effect on costs of realistic variations in wind capacity and power prices

    International Nuclear Information System (INIS)

    Miller, A.I.; Duffey, R.

    2005-01-01

    Can electricity from high-capacity nuclear reactors be blended with the variable output of wind turbines to produce electrolytic hydrogen competitively? Future energy hopes and emissions reduction scenarios place significant reliance on renewables, actually meaning largely new wind power both onshore and offshore. The opportunity exists for a synergy between high capacity factor nuclear plants and wind power using hydrogen by both as a 'currency' for use in transportation and industrial processing. But this use of hydrogen needs to be introduced soon. To be competitive with alternative sources, hydrogen produced by conventional electrolysis requires low-cost electricity (likely <2.5 Cent US/kW.h). One approach is to operate interruptibly allowing an installation to sell electricity when the grid price is high and to make hydrogen when it is low. Our previous studies have shown that this could be a cost-competitive approach with a nuclear power generator producing electricity around 3 Cent US/kW.h. Although similar unit costs are projected for wind-generated electricity, idleness of the hydrogen production (electrolysis) facility due to the variability of wind generated electricity imposes a serious cost penalty. This paper reports our latest results on the potential economics of blending electricity from nuclear and wind sources by using wind-generated power, when available, to augment the current through electrolysis equipment that is primarily nuclear-powered. A voltage penalty accompanies the higher current. A 10% increase in capital cost for electrolysis equipment enables it to accommodate the higher rate of hydrogen generation, while still being substantially cheaper than the capital cost of wind-dedicated electrolysis. Real-time data for electricity costs have been combined with real-time wind variability in our NuWind model. The variability in wind fields between sites was accommodated by assuming an average wind speed that produced an average electricity

  20. Hydrogen peroxide and polyamines act as double edged swords in plant abiotic stress responses

    Directory of Open Access Journals (Sweden)

    Kamala Gupta

    2016-09-01

    Full Text Available The specific genetic changes through which plants adapt to the multitude of environmental stresses are possible because of the molecular regulations in the system. These intricate regulatory mechanisms once unveiled will surely raise interesting questions. Polyamines and hydrogen peroxide have been suggested to be important signalling molecules during biotic and abiotic stresses. Hydrogen peroxide plays a versatile role from orchestrating physiological processes to stress response. It helps to achieve acclimatization and tolerance to stress by coordinating intra-cellular and systemic signalling systems. Polyamines, on the other hand, are low molecular weight polycationic aliphatic amines, which have been implicated in various stress responses. It is quite interesting to note that both hydrogen peroxide and polyamines have a fine line of inter-relation between them since the catabolic pathways of the latter releases hydrogen peroxide. In this review we have tried to illustrate the roles and their multifaceted functions of these two important signalling molecules based on current literature. This review also highlights the fact that over accumulation of hydrogen peroxide and polyamines can be detrimental for plant cells leading to toxicity and pre-mature cell death.

  1. Hydrogen Peroxide and Polyamines Act as Double Edged Swords in Plant Abiotic Stress Responses.

    Science.gov (United States)

    Gupta, Kamala; Sengupta, Atreyee; Chakraborty, Mayukh; Gupta, Bhaskar

    2016-01-01

    The specific genetic changes through which plants adapt to the multitude of environmental stresses are possible because of the molecular regulations in the system. These intricate regulatory mechanisms once unveiled will surely raise interesting questions. Polyamines and hydrogen peroxide have been suggested to be important signaling molecules during biotic and abiotic stresses. Hydrogen peroxide plays a versatile role from orchestrating physiological processes to stress response. It helps to achieve acclimatization and tolerance to stress by coordinating intra-cellular and systemic signaling systems. Polyamines, on the other hand, are low molecular weight polycationic aliphatic amines, which have been implicated in various stress responses. It is quite interesting to note that both hydrogen peroxide and polyamines have a fine line of inter-relation between them since the catabolic pathways of the latter releases hydrogen peroxide. In this review we have tried to illustrate the roles and their multifaceted functions of these two important signaling molecules based on current literature. This review also highlights the fact that over accumulation of hydrogen peroxide and polyamines can be detrimental for plant cells leading to toxicity and pre-mature cell death.

  2. Voltage Control in Wind Power Plants with Doubly Fed Generators

    DEFF Research Database (Denmark)

    Garcia, Jorge Martinez

    In this work, the process of designing a wind power plant composed of; doubly fed induction generators, a static compensator unit, mechanically switched capacitors and on-load tap changer, for voltage control is shown. The selected control structure is based on a decentralized system, since...... supplied by the doubly fed induction generator wind turbines is overcome by installing a reactive power compensator, i.e. a static compensator unit, which is coordinated with the plant control by a specific dispatcher. This dispatcher is set according to the result of the wind power plant load flow....... To release the operation of the converters during steady-state disturbances, mechanically switched capacitors are installed in the wind power plant, which due to their characteristics, they are appropriate for permanent disturbances compensation. The mechanically switched capacitors are controlled to allow...

  3. Next Generation Nuclear Plant Project Preliminary Project Management Plan

    International Nuclear Information System (INIS)

    Dennis J. Harrell

    2006-01-01

    This draft preliminary project management plan presents the conceptual framework for the Next Generation Nuclear Plant (NGNP) Project, consistent with the authorization in the Energy Policy Act of 2005. In developing this plan, the Idaho National Laboratory has considered three fundamental project planning options that are summarized in the following section. Each of these planning options is literally compliant with the Energy Policy Act of 2005, but each emphasizes different approaches to technology development risks, design, licensing and construction risks, and to the extent of commercialization support provided to the industry. The primary focus of this draft preliminary project management plan is to identify those activities important to Critical Decision-1, at which point a decision on proceeding with the NGNP Project can be made. The conceptual project framework described herein is necessary to establish the scope and priorities for the technology development activities. The framework includes: A reference NGNP prototype concept based on what is judged to be the lowest risk technology development that would achieve the needed commercial functional requirements to provide an economically competitive nuclear heat source and hydrogen production capability. A high-level schedule logic for design, construction, licensing, and acceptance testing. This schedule logic also includes an operational shakedown period that provides proof-of-principle to establish the basis for commercialization decisions by end-users. An assessment of current technology development plans to support Critical Decision-1 and overall project progress. The most important technical and programmatic uncertainties (risks) are evaluated, and potential mitigation strategies are identified so that the technology development plans may be modified as required to support ongoing project development. A rough-order-of-magnitude cost evaluation that provides an initial basis for budget planning. This

  4. Waste generation comparison: Coal-fired versus nuclear power plants

    International Nuclear Information System (INIS)

    LaGuardia, T.S.

    1998-01-01

    Low-level radioactive waste generation and disposal attract a great deal of attention whenever the nuclear industry is scrutinized by concerned parties, be it the media, the public, or political interests. It is therefore important to the nuclear industry that this issue be put into perspective relative to other current forms of energy production. Most of the country's fossil-fueled power comes from coal-fired plants, with oil and gas as other fuel sources. Most of the generated waste also comes from coal plants. This paper, therefore, compares waste quantities generated by a typical (1150-MW(electric)) pressurized water reactor (PWR) to that of a comparably sized coal-fired power plant

  5. Water electrolysis plants for hydrogen and oxygen production. Shipped to Tsuruga Power Station Unit No.1, and Tokai No.2 power station, the Japan Atomic Power Co

    International Nuclear Information System (INIS)

    Ueno, Syuichi; Sato, Takao; Ishikawa, Nobuhide

    1997-01-01

    Ebara's water electrolysis plants have been shipped to Tsuruga Power Station Unit No.1, (H 2 generation rate: 11 Nm 3 /h), and Tokai No.2 Power Station (H 2 generation rate: 36 Nm 3 /h), Japan Atomic Power Co. An outcome of a business agreement between Nissho Iwai Corporation and Norsk Hydro Electrolysers (Norway), this was the first time that such water electrolysis plants were equipped in Japanese boiling water reactor power stations. Each plant included an electrolyser (for generating hydrogen and oxygen), an electric power supply, a gas compression system, a dehumidifier system, an instrumentation and control system, and an auxiliary system. The plant has been operating almost continuously, with excellent feedback, since March 1997. (author)

  6. Double-side illuminated titania nanotubes for high volume hydrogen generation by water splitting

    Science.gov (United States)

    Mohapatra, Susanta K.; Mahajan, Vishal K.; Misra, Mano

    2007-11-01

    A sonoelectrochemical anodization method is proposed to synthesize TiO2 nanotubular arrays on both sides of a titanium foil (TiO2/Ti/TiO2). Highly ordered TiO2 nanotubular arrays of 16 cm2 area with uniform surface distribution can be obtained using this anodization procedure. These double-sided TiO2/Ti/TiO2 materials are used as both photoanode (carbon-doped titania nanotubes) and cathode (Pt nanoparticles dispersed on TiO2 nanotubes; PtTiO2/Ti/PtTiO2) in a specially designed photoelectrochemical cell to generate hydrogen by water splitting at a rate of 38 ml h-1. The nanomaterials are characterized by FESEM, HRTEM, STEM, EDS, FFT, SAED and XPS techniques. The present approach can be used for large-scale hydrogen generation using renewable energy sources.

  7. Safety operation of chromatography column system with discharging hydrogen radiolytically generated

    International Nuclear Information System (INIS)

    Watanabe, S; Sano, Y.; Nomura, K.; Koma, Y.; Okamoto, Y.

    2015-01-01

    The extraction chromatography technology is one of the promising methods for the partitioning of minor actinides (Am and Cm) from spent nuclear fuels. In the extraction chromatography system, the accumulation of hydrogen gas in the chromatography column is suspected to lead to fire or explosion. In order to prevent hazardous accidents, it is necessary to evaluate behaviors of gas radiolytically generated inside the column. In this study, behaviors of gas inside the extraction chromatography column were investigated through experiments and Computation Fluid Dynamics (CFD) simulation. N_2 gas once accumulated as bubbles in the packed bed was hardly discharged by the flow of mobile phase. However, the CFD simulation and X-ray imaging on γ-ray irradiated column revealed that during operation the hydrogen gas generated in the column was dissolved into the mobile phase without accumulation and then discharged. (authors)

  8. Hydrogen generation in SRAT with nitric acid and late washing flowsheets

    International Nuclear Information System (INIS)

    Hsu, C.W.

    1992-01-01

    Recently, SRTC recommended two process changes: (1) a final wash of the tetraphenylborate precipitate feed slurry and (2) the use of nitric acid to neutralize the sludge in the SRAT. The first change produced an aqueous hydrolysis product (PHA) with higher formic acid/formate and copper concentration, and reduced the nitrate content in the PHA by an order of magnitude. The second change is to substitute part of formic acid added to the SRAT with nitric acid, and therefore may reduce the hydrogen generated in the SRAT as well as provide nitrate as an oxidant to balance the redox state of the melter feed. The purpose of this report is to determine the pertinent variables that could affect the hydrogen generation rate with these process changes

  9. Photo-driven autonomous hydrogen generation system based on hierarchically shelled ZnO nanostructures

    International Nuclear Information System (INIS)

    Kim, Heejin; Yong, Kijung

    2013-01-01

    A quantum dot semiconductor sensitized hierarchically shelled one-dimensional ZnO nanostructure has been applied as a quasi-artificial leaf for hydrogen generation. The optimized ZnO nanostructure consists of one dimensional nanowire as a core and two-dimensional nanosheet on the nanowire surface. Furthermore, the quantum dot semiconductors deposited on the ZnO nanostructures provide visible light harvesting properties. To realize the artificial leaf, we applied the ZnO based nanostructure as a photoelectrode with non-wired Z-scheme system. The demonstrated un-assisted photoelectrochemical system showed the hydrogen generation properties under 1 sun condition irradiation. In addition, the quantum dot modified photoelectrode showed 2 mA/cm 2 current density at the un-assisted condition

  10. Next-Generation Sequencing and Genome Editing in Plant Virology

    Directory of Open Access Journals (Sweden)

    Ahmed Hadidi

    2016-08-01

    Full Text Available Next-generation sequencing (NGS has been applied to plant virology since 2009. NGS provides highly efficient, rapid, low cost DNA or RNA high-throughput sequencing of the genomes of plant viruses and viroids and of the specific small RNAs generated during the infection process. These small RNAs, which cover frequently the whole genome of the infectious agent, are 21-24 nt long and are known as vsRNAs for viruses and vd-sRNAs for viroids. NGS has been used in a number of studies in plant virology including, but not limited to, discovery of novel viruses and viroids as well as detection and identification of those pathogens already known, analysis of genome diversity and evolution, and study of pathogen epidemiology. The genome engineering editing method, clustered regularly interspaced short palindromic repeats (CRISPR-Cas9 system has been successfully used recently to engineer resistance to DNA geminiviruses (family, Geminiviridae by targeting different viral genome sequences in infected Nicotiana benthamiana or Arabidopsis plants. The DNA viruses targeted include tomato yellow leaf curl virus and merremia mosaic virus (begomovirus; beet curly top virus and beet severe curly top virus (curtovirus; and bean yellow dwarf virus (mastrevirus. The technique has also been used against the RNA viruses zucchini yellow mosaic virus, papaya ringspot virus and turnip mosaic virus (potyvirus and cucumber vein yellowing virus (ipomovirus, family, Potyviridae by targeting the translation initiation genes eIF4E in cucumber or Arabidopsis plants. From these recent advances of major importance, it is expected that NGS and CRISPR-Cas technologies will play a significant role in the very near future in advancing the field of plant virology and connecting it with other related fields of biology.Keywords: Next-generation sequencing, NGS, plant virology, plant viruses, viroids, resistance to plant viruses by CRISPR-Cas9

  11. Graphene sheets/cobalt nanocomposites as low-cost/high-performance catalysts for hydrogen generation

    International Nuclear Information System (INIS)

    Zhang, Fei; Hou, Chengyi; Zhang, Qinghong; Wang, Hongzhi; Li, Yaogang

    2012-01-01

    The production of clean and renewable hydrogen through the hydrolysis of sodium borohydride has received much attention owing to increasing global energy demands. Graphene sheets/cobalt (GRs/Co) nanocomposites, which are highly efficient catalysts, have been prepared using a one-step solvothermal method in ethylene glycol. Co 2+ salts were converted to Co nanoparticles, which were simultaneously inserted into the graphene layers with the reduction of graphite oxide sheets to GRs. The as-synthesized samples were characterized by X-ray diffraction, Fourier transform infrared spectra, Raman spectroscopy, field emission scanning electron microscopy, transmission electron microscopy, high-resolution transmission electron microscopy and vibrating sample magnetometer. The maximum saturation magnetization value reached 80.8 emu g −1 , meaning they are more suitable for magnet-controlled generation of H 2 than noble metal catalysts. The catalytic activity of the composite was investigated by the hydrolysis of sodium borohydride in aqueous solution both with and without a GRs support. It was found that the high electronic conductive GRs support increased the hydrogen generation rate (about two times) compared with pure cobalt. The improved hydrogen generation rate, low cost and uncomplicated recycling makes the GRs/Co nanocomposites promising candidates as catalysts for hydrogen generation. Highlights: ► Graphene sheets/cobalt nanocomposites were prepared by a one-step solvothermal method. ► The maximum saturation magnetization value of the composites reached 80.8 emu g −1 . ► The graphene support greatly increased the catalytic activity of cobalt. ► An easily removed, recycled and controlled functional filter was obtained.

  12. Vibrations measurement at the Embalse nuclear power plant's electrical generator

    International Nuclear Information System (INIS)

    Salomoni, R.C.; Belinco, C.G.; Pastorini, A.J.; Sacchi, M.A.

    1987-01-01

    After the modifications made at the Embalse nuclear power plant's electrical generator to reduce its vibration level produced by electromagnetic phenomena, it was necessary to perform measurements at the new levels, under different areas and power conditions. To this purpose, a work was performed jointly with the 'Vibrations Team' of the ANSALDO Company (the generator constructor) and the Hydrodynamic Assays Division under the coordination and supervision of the plant's electrical maintenance responsible. This paper includes the main results obtained and the instrumentation criteria and analysis performed. (Author)

  13. Simulation of gaseous emissions from electricity generating plant

    International Nuclear Information System (INIS)

    Bellhouse, G.M.; Whittington, H.W.

    1996-01-01

    In electricity supply networks, traditional dispatch algorithms are based on features such as economics and plant availability. Annual limits on emissions from fossil-fuelled stations are regarded as a restriction and set a ceiling on generation from particular stations. With the impending introduction of financial penalties on emissions, for example cal bon taxation, algorithms will have to be developed which allow the dispatch engineer to assess the cost in real-time of different generation options involving fossil-fuelled plants. Such an algorithm is described in this paper. (UK)

  14. System design study of a membrane reforming hydrogen production plant using a small sized sodium cooled reactor

    International Nuclear Information System (INIS)

    Chikazawa, Y.; Konomura, M.; Hori, T.; Sato, H.; Uchida, S.

    2004-01-01

    In this study, a membrane reforming hydrogen production plant using a small sized sodium cooled reactor was designed as one of promising concepts. In the membrane reformer, methane and steam are reformed into carbon dioxide and hydrogen with sodium heat at a temperature 500 deg-C. In the equilibrium condition, steam reforming proceeds with catalyst at a temperature more than 800 deg-C. Using membrane reformers, the steam reforming temperature can be decreased from 800 to 500 deg-C because the hydrogen separation membrane removes hydrogen selectively from catalyst area and the partial pressure of hydrogen is kept much lower than equilibrium condition. In this study, a hydrogen and electric co-production plant has been designed. The reactor thermal output is 375 MW and 25% of the thermal output is used for hydrogen production (70000 Nm 3 /h). The hydrogen production cost is estimated to 21 yen/Nm 3 but it is still higher than the economical goal (17 yen/Nm 3 ). The major reason of the high cost comes from the large size of hydrogen separation reformers because of the limit of hydrogen separation efficiency of palladium membrane. A new highly efficient hydrogen separation membrane is needed to reduce the cost of hydrogen production using membrane reformers. There is possibility of multi-tube failure in the membrane reformers. In future study, a design of measures against tube failure and elemental experiments of reaction between sodium and reforming gas will be needed. (authors)

  15. Risks of turbine generators at WWER-440 nuclear power plants

    International Nuclear Information System (INIS)

    Virolainen, T.; Marttila, J.; Aulamo, H.

    1998-01-01

    Many serious fires and incidents have occurred in the turbine halls of nuclear power plants, resulting in serious damage and long shutdown outages. Some of these incidents have endangered the safe shutdown of the plants because of the location of lack of vital fire protection safety systems. A detailed analysis is necessary for all those plants that have equipment important for safe shutdown located in the turbine hall or its vicinity without strict fire separation by fire rated barriers. A reduction in the fire frequencies of the turbine hall is an additional way of improving safety. This is possible by improving all aspects of turbine generator operation. (author)

  16. Prediction of the amount of hydrogen generated during a molten fuel-coolant interaction

    International Nuclear Information System (INIS)

    Matthern, G.E.; Neuman, J.E.; Madsen, W.W.; Close, J.A.

    1990-01-01

    The model in development predicts the production of hydrogen as a result of a molten fuel-coolant interaction in a water-cooled nuclear reactor. It has three interrelated modules: kinetics, heat transfer, and hydrodynamics. Second and third order rates are assumed for uranium and aluminum respectively, the chosen fuel and cladding. Heat is generated by chemical reaction and radioactive decay and dissipated through radiation and convection. Dispersion of the melt as it descends through a pool of water is modeled using the Weber number, which ratios the shear forces due to the relative velocities of the fluid and the metal to the surface tension of the metal. Hydrogen generation is sensitive to the initial melt temperature and to the assumptions made about the modes of heat transfer, but not the the impact velocity of the metal particle. The hydrogen generation per unit mass of uranium generally increases as the initial particle size decreases suggesting that the kinetics rather than the heat transfer controls the energy balance

  17. Investigation of thermolytic hydrogen generation rate of tank farm simulated and actual waste

    Energy Technology Data Exchange (ETDEWEB)

    Martino, C. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Newell, D. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Woodham, W. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Pareizs, J. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Edwards, T. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Howe, A. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2017-11-15

    To support resolution of Potential Inadequacies in the Safety Analysis for the Savannah River Site (SRS) Tank Farm, Savannah River National Laboratory conducted research to determine the thermolytic hydrogen generation rate (HGR) with simulated and actual waste. Gas chromatography methods were developed and used with air-purged flow systems to quantify hydrogen generation from heated simulated and actual waste at rates applicable to the Tank Farm Documented Safety Analysis (DSA). Initial simulant tests with a simple salt solution plus sodium glycolate demonstrated the behavior of the test apparatus by replicating known HGR kinetics. Additional simulant tests with the simple salt solution excluding organics apart from contaminants provided measurement of the detection and quantification limits for the apparatus with respect to hydrogen generation. Testing included a measurement of HGR on actual SRS tank waste from Tank 38. A final series of measurements examined HGR for a simulant with the most common SRS Tank Farm organics at temperatures up to 140 °C. The following conclusions result from this testing.

  18. Hydrogen.

    Science.gov (United States)

    Bockris, John O'M

    2011-11-30

    The idea of a "Hydrogen Economy" is that carbon containing fuels should be replaced by hydrogen, thus eliminating air pollution and growth of CO₂ in the atmosphere. However, storage of a gas, its transport and reconversion to electricity doubles the cost of H₂ from the electrolyzer. Methanol made with CO₂ from the atmosphere is a zero carbon fuel created from inexhaustible components from the atmosphere. Extensive work on the splitting of water by bacteria shows that if wastes are used as the origin of feed for certain bacteria, the cost for hydrogen becomes lower than any yet known. The first creation of hydrogen and electricity from light was carried out in 1976 by Ohashi et al. at Flinders University in Australia. Improvements in knowledge of the structure of the semiconductor-solution system used in a solar breakdown of water has led to the discovery of surface states which take part in giving rise to hydrogen (Khan). Photoelectrocatalysis made a ten times increase in the efficiency of the photo production of hydrogen from water. The use of two electrode cells; p and n semiconductors respectively, was first introduced by Uosaki in 1978. Most photoanodes decompose during the photoelectrolysis. To avoid this, it has been necessary to create a transparent shield between the semiconductor and its electronic properties and the solution. In this way, 8.5% at 25 °C and 9.5% at 50 °C has been reached in the photo dissociation of water (GaP and InAs) by Kainthla and Barbara Zeleney in 1989. A large consortium has been funded by the US government at the California Institute of Technology under the direction of Nathan Lewis. The decomposition of water by light is the main aim of this group. Whether light will be the origin of the post fossil fuel supply of energy may be questionable, but the maximum program in this direction is likely to come from Cal. Tech.

  19. Hydrocarbon reforming catalysts and new reactor designs for compact hydrogen generators

    Energy Technology Data Exchange (ETDEWEB)

    Schaefer, A.; Schwab, E.; Urtel, H. [BASF SE, Ludwigshafen (Germany); Farrauto, R. [BASF Catalysts LLC, Iselin, NJ (United States)

    2010-12-30

    A hydrogen based future energy scenario will use fuel cells for the conversion of chemically stored energy into electricity. Depending upon the type of fuel cell, different specifications will apply for the feedstock which is converted in the cell, ranging from very clean hydrogen for PEM-FC's to desulfurized methane for SOFC and MCFC technology. For the foreseeable future, hydrogen will be supplied by conventional reforming, however operated in compact and dynamic reformer designs. This requires that known catalyst formulations are offered in specific geometries, giving flexibility for novel reactor design options. These specific geometries can be special tablet shapes as well as monolith structures. Finally, also nonhydrocarbon feedstock might be used in special applications, e.g. bio-based methanol and ethanol. BASF offers catalysts for the full process chain starting from feedstock desulfurization via reforming, high temperature shift, low temperature shift to CO fine polishing either via selective oxidation or selective methanation. Depending upon the customer's design, most stages can be served either with precious metal based monolith solutions or base metal tablet solutions. For the former, we have taken the automobile catalyst monolith support and extended its application to the fuel cell hydrogen generation. Washcoats of precious metal supported catalysts can for example be deposited on ceramic monoliths and/or metal heat exchangers for efficient generation of hydrogen. Major advantages are high through puts due to more efficient heat transfer for catalysts on metal heat exchangers, lower pressure drop with greater catalyst mechanical and thermal stability compared to particulate catalysts. Base metal tablet catalysts on the other hand can have intrinsic cost advantages, larger fractions of the reactor can be filled with active mass, and if produced in unconventional shape, again novel reactor designs are made possible. Finally, if it comes to

  20. Cuboid Ni2 P as a Bifunctional Catalyst for Efficient Hydrogen Generation from Hydrolysis of Ammonia Borane and Electrocatalytic Hydrogen Evolution.

    Science.gov (United States)

    Du, Yeshuang; Liu, Chao; Cheng, Gongzhen; Luo, Wei

    2017-11-16

    The design of high-performance catalysts for hydrogen generation is highly desirable for the upcoming hydrogen economy. Herein, we report the colloidal synthesis of nanocuboid Ni 2 P by the thermal decomposition of nickel chloride hexahydrate (NiCl 2 ⋅6 H 2 O) and trioctylphosphine. The obtained nanocuboid Ni 2 P was characterized by using powder X-ray diffraction, transmission electron microscopy, energy-dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, and inductively coupled plasma atomic emission spectroscopy. For the first time, the as-synthesized nanocuboid Ni 2 P is used as a bifunctional catalyst for hydrogen generation from the hydrolysis of ammonia borane and electrocatalytic hydrogen evolution. Owing to the strong synergistic electronic effect between Ni and P, the as-synthesized Ni 2 P exhibits catalytic performance that is superior to its counterpart without P doping. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Minimisation of Generation Variability of a Group of Wind Plants

    Directory of Open Access Journals (Sweden)

    Dubravko Sabolić

    2017-09-01

    Full Text Available Minimisation of variability of energy delivered from a group of wind plants into the power system using portfolio theory approach was studied. One of the assumptions of that theory is Gaussian distribution of the sample, which is not satisfied in case of wind generation. Therefore, optimisation of a “portfolio” of plants with different goal functions was studied. It was supposed that a decision on distribution of a fixed amount of generation capacity to be installed among a set of geographical locations with known wind statistics is to be made with minimised variability of generation as a goal. In that way the statistical cancellation of variability would be used in the best possible manner. This article is a brief report on results of such an investigation. An example of nine locations in Croatia was used. These locations’ wind statistics are known from historic generation data.

  2. Clinch river breeder reactor plant steam generator water quality

    International Nuclear Information System (INIS)

    Van Hoesen, D.; Lowe, P.A.

    1975-01-01

    The recent problems experienced by some LWR Steam Generators have drawn attention to the importance of system water quality and water/ steam side corrosion. Several of these reactor plants have encountered steam generator failures due to accelerated tube corrosion caused, in part, by poor water quality and corrosion control. The CRBRP management is aware of these problems, and the implications that they have for the Clinch River Breeder Reactor Plant (CPBRP) Steam Generator System (SGS). Consequently, programs are being implemented which will: 1) investigate the corrosion mechanisms which may be present in the CRBRP SGS; 2) assure steam generator integrity under design and anticipated off-normal water quality conditions; and 3) assure that the design water quality levels are maintained at all times. However, in order to understand the approach being used to examine this potential problem, it is first necessary to look at the CRBRP SGS and the corrosion mechanisms which may be present

  3. Clinch river breeder reactor plant steam generator water quality

    Energy Technology Data Exchange (ETDEWEB)

    Van Hoesen, D; Lowe, P A

    1975-07-01

    The recent problems experienced by some LWR Steam Generators have drawn attention to the importance of system water quality and water/ steam side corrosion. Several of these reactor plants have encountered steam generator failures due to accelerated tube corrosion caused, in part, by poor water quality and corrosion control. The CRBRP management is aware of these problems, and the implications that they have for the Clinch River Breeder Reactor Plant (CPBRP) Steam Generator System (SGS). Consequently, programs are being implemented which will: (1) investigate the corrosion mechanisms which may be present in the CRBRP SGS; (2) assure steam generator integrity under design and anticipated off-normal water quality conditions; and (3) assure that the design water quality levels are maintained at all times. However, in order to understand the approach being used to examine this potential problem, it is first necessary to look at the CRBRP SGS and the corrosion mechanisms which may be present.

  4. The hydrogen generated as a gas and storage in Zircaloy during steam quenching

    International Nuclear Information System (INIS)

    Garcia, Eduardo A.

    2000-01-01

    A simple one-dimensional diffusion model has been developed for the complex process of Zircaloy oxidation during steam quenching, calculating the hydrogen liberated as a gas and the hydrogen stored in the metal. The model was developed on the basis of small-scale separate-effects quench experiments performed at Forschungszentrum Karlsruhe. The new oxide surface and the new metallic surface produced by cracking of the oxide during quenching are calculated for each experiment performed at 1200 centigrade, 1400 centigrade and 1600 centigrade using as-received Zircaloy-4 (no pre-oxidation) and with Zircaloy specimens pre-oxidized to give oxide thickness of 100μm and 300μm. The results are relevant to accident management in nuclear power plants. (author)

  5. Next Generation Nuclear Plant Steam Generator and Intermediate Heat Exchanger Materials Research and Development Plan

    Energy Technology Data Exchange (ETDEWEB)

    J. K. Wright

    2010-09-01

    DOE has selected the High Temperature Gas-cooled Reactor (HTGR) design for the Next Generation Nuclear Plant (NGNP) Project. The NGNP will demonstrate the use of nuclear power for electricity and hydrogen production. It will have an outlet gas temperature in the range of 900°C and a plant design service life of 60 years. The reactor design will be a graphite moderated, helium-cooled, prismatic or pebble-bed reactor and use low-enriched uranium, Tri-Isotopic (TRISO)-coated fuel. The plant size, reactor thermal power, and core configuration will ensure passive decay heat removal without fuel damage or radioactive material releases during accidents. The NGNP Materials Research and Development (R&D) Program is responsible for performing R&D on likely NGNP materials in support of the NGNP design, licensing, and construction activities. Today’s high-temperature alloys and associated ASME Codes for reactor applications are approved up to 760°C. However, some primary system components, such as the Intermediate Heat Exchanger (IHX) for the NGNP will require use of materials that can withstand higher temperatures. The thermal, environmental, and service life conditions of the NGNP will make selection and qualification of some high-temperature materials a significant challenge. Examples include materials for the core barrel and core internals, such as the control rod sleeves. The requirements of the materials for the IHX are among the most demanding. Selection of the technology and design configuration for the NGNP must consider both the cost and risk profiles to ensure that the demonstration plant establishes a sound foundation for future commercial deployments. The NGNP challenge is to achieve a significant advancement in nuclear technology while at the same time setting the stage for an economically viable deployment of the new technology in the commercial sector soon after 2020. A number of solid solution strengthened nickel based alloys have been considered for

  6. Power plant project success through total productive generation

    Energy Technology Data Exchange (ETDEWEB)

    Kaivola, R.; Tamminen, L.

    1996-11-01

    The Total Productive Generation concept (TPG) defines the lines of action adopted by IVO Generation Services Ltd (IGS) for the operation and maintenance of power plants. The TPG concept is based on procedures tested in practice. The main idea of TPG is continuous development of quality, which is a joint effort of the entire staff. Its objective is to benefit IGS`s own staff and, in particular, the company`s customers. (orig.)

  7. Soviet steam generator technology: fossil fuel and nuclear power plants

    International Nuclear Information System (INIS)

    Rosengaus, J.

    1987-01-01

    In the Soviet Union, particular operational requirements, coupled with a centralized planning system adopted in the 1920s, have led to a current technology which differs in significant ways from its counterparts elsewhere in the would and particularly in the United States. However, the monograph has a broader value in that it traces the development of steam generators in response to the industrial requirements of a major nation dealing with the global energy situation. Specifically, it shows how Soviet steam generator technology evolved as a result of changing industrial requirements, fuel availability, and national fuel utilization policy. The monograph begins with a brief technical introduction focusing on steam-turbine power plants, and includes a discussion of the Soviet Union's regional power supply (GRES) networks and heat and power plant (TETs) systems. TETs may be described as large central co-generating stations which, in addition to electricity, provide heat in the form of steam and hot water. Plants of this type are a common feature of the USSR today. The adoption of these cogeneration units as a matter of national policy has had a central influence on Soviet steam generator technology which can be traced throughout the monograph. The six chapters contain: a short history of steam generators in the USSR; steam generator design and manufacture in the USSR; boiler and furnace assemblies for fossil fuel-fired power stations; auxiliary components; steam generators in nuclear power plants; and the current status of the Soviet steam generator industry. Chapters have been abstracted separately. A glossary is included containing abbreviations and acronyms of USSR organizations. 26 references

  8. Assessment study of devices from the generation of electricity from stored hydrogen

    International Nuclear Information System (INIS)

    Ackerman, J.P.; Barghusen, J.J.; Link, L.E.

    1975-12-01

    A study was performed to evaluate alternative methods for the generation of electricity from stored hydrogen. The generation systems considered were low-temperature and high-temperature fuel cells, gas turbines and steam turbines. These systems were evaluated in terms of present-day technology and future (1995) technology. Of primary interest were the costs and efficiencies of the devices, the versatility of the devices toward various types of gaseous feeds, and the likelihood of commercial development. On the basis of these evaluations, recommendations were made describing the areas of technology which should be developed

  9. Simultaneous Hydrogen Generation and Waste Acid Neutralization in a Reverse Electrodialysis System

    KAUST Repository

    Hatzell, Marta C.

    2014-09-02

    Waste acid streams produced at industrial sites are often co-located with large sources of waste heat (e.g., industrial exhaust gases, cooling water, and heated equipment). Reverse electrodialysis (RED) systems can be used to generate electrical power and hydrogen gas using waste heat-derived solutions, but high electrode overpotentials limit system performance. We show here that an ammonium bicarbonate (AmB) RED system can achieve simultaneous waste acid neutralization and in situ hydrogen production, while capturing energy from excess waste heat. The rate of acid neutralization was dependent on stack flow rate and increased 50× (from 0.06 ± 0.04 to 3.0 ± 0.32 pH units min -1 m-2 membrane), as the flow rate increased 6× (from 100 to 600 mL min-1). Acid neutralization primarily took place due to ammonium electromigration (37 ± 4%) and proton diffusion (60 ± 5%). The use of a synthetic waste acid stream as a catholyte (pH ≈ 2) also increased hydrogen production rates by 65% (from 5.3 ± 0.5 to 8.7 ± 0.1 m3 H2 m-3 catholyte day -1) compared to an AmB electrolyte (pH ≈ 8.5). These findings highlight the potential use of dissimilar electrolytes (e.g., basic anolyte and acidic catholyte) for enhanced power and hydrogen production in RED stacks. © 2014 American Chemical Society.

  10. Performance of Generating Plant: Managing the Changes. Part 2: Thermal Generating Plant Unavailability Factors and Availability Statistics

    Energy Technology Data Exchange (ETDEWEB)

    Curley, G. Michael [North American Electric Reliability Corporation (United States); Mandula, Jiri [International Atomic Energy Agency (IAEA)

    2008-05-15

    The WEC Committee on the Performance of Generating Plant (PGP) has been collecting and analysing power plant performance statistics worldwide for more than 30 years and has produced regular reports, which include examples of advanced techniques and methods for improving power plant performance through benchmarking. A series of reports from the various working groups was issued in 2008. This reference presents the results of Working Group 2 (WG2). WG2's main task is to facilitate the collection and input on an annual basis of power plant performance data (unit-by-unit and aggregated data) into the WEC PGP database. The statistics will be collected for steam, nuclear, gas turbine and combined cycle, hydro and pump storage plant. WG2 will also oversee the ongoing development of the availability statistics database, including the contents, the required software, security issues and other important information. The report is divided into two sections: Thermal generating, combined cycle/co-generation, combustion turbine, hydro and pumped storage unavailability factors and availability statistics; and nuclear power generating units.

  11. Hydrogen bond dynamics governs the effective photoprotection mechanism of plant phenolic sunscreens.

    Science.gov (United States)

    Liu, Fang; Du, Likai; Lan, Zhenggang; Gao, Jun

    2017-02-15

    Sinapic acid derivatives are important sunscreen species in natural plants, which could provide protection from solar UV radiation. Using a combination of ultrafast excited state dynamics, together with classical molecular dynamics studies, we demonstrate that there is direct coupling of hydrogen bond motion with excited state photoprotection dynamics as part of the basic mechanism in solution. Beyond the intra-molecular degree of freedom, the inter-molecular motions on all timescales are potentially important for the photochemical or photophysical events, ranging from the ultrafast hydrogen bond motion to solvent rearrangements. This provides not only an enhanced understanding of the anomalous experimental spectroscopic results, but also the key idea in the development of sunscreen agents with improved photo-chemical properties. We suggest that the hydrogen bond dynamics coupled excited state photoprotection mechanism may also be possible in a broad range of bio-related molecules in the condensed phase.

  12. 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)

  13. Concept for the analysis of hydrogen problems in nuclear power plants after accidents

    International Nuclear Information System (INIS)

    PreuBer, G.; Freudenstein, K.F.; Reinders, R.

    1997-01-01

    After accidents in nuclear power plants, which lead to a overheating of the core up to a partial or complete core melting, hydrogen is produced due to the reaction of fuel cladding and other metallic structures of the core with the cooling water. This hydrogen enters the containment through a leak of the primary system or at reactor pressure vessel failure. The danger of fast deflagration or explosions appears which may affect the containment. For the analysis of the containment phenomena two different types of computer codes are used, lumped parameter codes and 3D codes. This paper describes the advantages and the limitations of both methods. The codes used by Siemens KWU are presented with some examples for hydrogen analyses. A prospect of further development is given. (author)

  14. Multi-Generation Concentrating Solar-Hydrogen Power System for Sustainable Rural Development

    Energy Technology Data Exchange (ETDEWEB)

    Krothapalli, A.; Greska, B.

    2007-07-01

    This paper describes an energy system that is designed to meet the demands of rural populations that currently have no access to grid-connected electricity. Besides electricity, it is well recognized that rural populations need at least a centralized refrigeration system for storage of medicines and other emergency supplies, as well as safe drinking water. Here we propose a district system that will employ a multi-generation concentrated solar power (CSP) system that will generate electricity and supply the heat needed for both absorption refrigeration and membrane distillation (MD) water purification. The electricity will be used to generate hydrogen through highly efficient water electrolysis and individual households can use the hydrogen for generating electricity, via affordable proton exchange membrane (PEM) fuel cells, and as a fuel for cooking. The multi-generation system is being developed such that its components will be easy to manufacture and maintain. As a result, these components will be less efficient than their typical counterparts but their low cost-to-efficiency ratio will allow for us to meet our installation cost goal of $1/Watt for the entire system. The objective of this paper is to introduce the system concept and discuss the system components that are currently under development. (auth)

  15. The effect of plutonium dioxide water surface coverage on the generation of hydrogen and oxygen

    Energy Technology Data Exchange (ETDEWEB)

    Veirs, Douglas K. [Los Alamos National Laboratory; Berg, John M. [Los Alamos National Laboratory; Crowder, Mark L. [Savannah River National Laboratory

    2012-06-20

    The conditions for the production of oxygen during radiolysis of water adsorbed onto plutonium dioxide powder are discussed. Studies in the literature investigating the radiolysis of water show that both oxygen and hydrogen can be generated from water adsorbed on high-purity plutonium dioxide powder. These studies indicate that there is a threshold in the amount of water below which oxygen is not generated. The threshold is associated with the number of monolayers of adsorbed water and is shown to occur at approximately two monolayers of molecularly adsorbed water. Material in equilibrium with 50% relative humidity (RH) will be at the threshold for oxygen generation. Using two monolayers of molecularly adsorbed water as the threshold for oxygen production, the total pressure under various conditions is calculated assuming stoichiometric production of hydrogen and oxygen. The specific surface area of the oxide has a strong effect on the final partial pressure. The specific surface areas resulting in the highest pressures within a 3013 container are evaluated. The potential for oxygen generation is mitigated by reduced relative humidity, and hence moisture adsorption, at the oxide surface which occurs if the oxide is warmer than the ambient air. The potential for oxygen generation approaches zero as the temperature difference between the ambient air and the material approaches 6 C.

  16. Commercial Optimization of a 100 kg/day PEM based Hydrogen Generator For Energy and Industrial Applications

    International Nuclear Information System (INIS)

    Moulthrop, L.; Anderson, E.; Chow, O.; Friedland, R.; Maloney, T.; Schiller, M.

    2006-01-01

    Commercial hydrogen generators using PEM water electrolysis are well proven, serving industrial applications worldwide in over 50 countries. Now, market and environmental requirements are converging to demand larger on-site hydrogen generators. North American liquid H 2 shortages, increasing trucking costs, developing economies with no liquid infrastructure, utilities, and forklift fuel cell fueling applications are all working to increase market demand for commercial on-site H 2 generation. These commercial applications may be satisfied by a 100 kg H 2 /day module; this platform can be the pathway towards a 500 kg H 2 /day generator desired for small fore-court hydrogen vehicle fueling stations. This paper discusses the steps necessary and activities already underway to develop a 100 to 500 kg H 2 /day PEM hydrogen generator platform to meet commercial market cost targets and approach US DoE transportation fueling cost targets. (authors)

  17. Fuel procurement for first generation fusion power plants

    International Nuclear Information System (INIS)

    Gore, B.F.; Hendrickson, P.L.

    1976-09-01

    The provision of deuterium, tritium, lithium and beryllium fuel materials for fusion power plants is examined in this document. Possible fusion reactions are discussed for use in first generation power plants. Requirements for fuel materials are considered. A range of expected annual consumption is given for each of the materials for a 1000 megawatts electric (MWe) fusion power plant. Inventory requirements are also given. Requirements for an assumed fusion power plant electrical generating capacity of 10 6 MWe (roughly twice present U.S. generating capacity) are also given. The supply industries are then examined for deuterium, lithium, and beryllium. Methods are discussed for producing the only tritium expected to be purchased by a commercial fusion industry--an initial inventory for the first plant. Present production levels and methods are described for deuterium, lithium and beryllium. The environmental impact associated with production of these materials is then discussed. The toxicity of beryllium is described, and methods are indicated to keep worker exposure to beryllium as low as achievable

  18. Performance of Generating Plant: Managing the Changes. Part 1: International availability data exchange for thermal generating plant

    Energy Technology Data Exchange (ETDEWEB)

    Stallard, G.S.; Deschaine, R. [Black and Veatch (United States)

    2008-05-15

    The WEC Committee on the Performance of Generating Plant (PGP) has been collecting and analysing power plant performance statistics worldwide for more than 30 years and has produced regular reports, which include examples of advanced techniques and methods for improving power plant performance through benchmarking. A series of reports from the various working groups was issued in 2008. This reference presents the results of Working Group 1 (WG1). WG1's primary focus is to analyse the best ways to measure, evaluate, and apply power plant performance and availability data to promote plant performance improvements worldwide. The paper explores the specific work activities of 2004-2007 to extend traditional analysis and benchmarking frameworks. It is divided into two major topics: Overview of current electric supply industry issues/trends; and, Technical Methods/Tools to evaluate performance in today's ESI.

  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. Performance of Generating Plant: New Metrics for Industry in Transition

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2010-09-15

    This report is the result of the work of the Performance of Generating Plant task force of the World Energy Council. The report examines the challenges of measuring and improving performance and considers some of the issues related to this field.

  1. Diagnostic knowledge generation of nuclear power plants using knowledge compilers

    International Nuclear Information System (INIS)

    Yoshikawa, Shinji; Endou, Akira; Ikeda, Mitsuru; Mizoguchi, Riichiro

    1994-01-01

    This paper discusses a method to generate diagnostic knowledge of nuclear power plants, from commonly accepted physical knowledge and design information about plant configuration. This method is based on qualitative reasoning, which is advantageous to numerical information processing in the sense that system can explain why and how directly applicable knowledge is correctly generated, and that knowledge base is highly reusable and expandable because it is independent on detailed numerical design specifications. However, reasoning ambiguity has been found as the largest problem in applying the technique to nuclear power plants. The proposed approach mainly consists of a knowledge representation scheme, reasoning algorithm, and qualitative model construction method. (author). 4 refs, 8 figs, 1 tab

  2. Thermo hydrodynamical analyses of steam generator of nuclear power plant

    International Nuclear Information System (INIS)

    Petelin, S.; Gregoric, M.

    1984-01-01

    SMUP computer code for stationary model of a U-tube steam generator of a PWR nuclear power plant was developed. feed water flow can enter through main and auxiliary path. The computer code is based on the one dimensional mathematical model. Among the results that give an insight into physical processes along the tubes of steam generator are distribution of temperatures, water qualities, heat transfer rates. Parametric analysis permits conclusion on advantage of each design solution regarding heat transfer effects and safety of steam generator. (author)

  3. HyPEP-FY 07 Annual Report: A Hydrogen Production Plant Efficiency Calculation Program

    Energy Technology Data Exchange (ETDEWEB)

    Chang Oh

    2007-09-01

    The Very High Temperature Gas-Cooled Reactor (VHTR) coupled to the High Temperature Steam Electrolysis (HTSE) process is one of two reference integrated systems being investigated by the U.S. Department of Energy and Idaho National Laboratory for the production of hydrogen. In this concept the VHTR outlet temperature of 900 °C provides thermal energy and high efficiency electricity for the electrolysis of steam in the HTSE process. In the second reference system the Sulfur Iodine (SI) process is coupled to the VHTR to produce hydrogen thermochemically. In the HyPEP project we are investigating and characterizing these two reference systems with respect to production, operability, and safety performance criteria. Under production, plant configuration and working fluids are being studied for their effect on efficiency. Under operability, control strategies are being developed with the goal of maintaining equipment within operating limits while meeting changes in demand. Safety studies are to investigate plant response for equipment failures. Specific objectives in FY07 were (1) to develop HyPEP Beta and verification and validation (V&V) plan, (2) to perform steady state system integration, (3) to perform parametric studies with various working fluids and power conversion unit (PCU) configurations, (4) the study of design options such as pressure, temperature, etc. (5) to develop a control strategy and (6) to perform transient analyses for plant upsets, control strategy, etc for hydrogen plant with PCU. This report describes the progress made in FY07 in each of the above areas. (1) The HyPEP code numeric scheme and Graphic User Interface have been tested and refined since the release of the alpha version a year ago. (2) The optimal size and design condition for the intermediate heat exchanger, one of the most important components for integration of the VHTR and HTSE plants, was estimated. (3) Efficiency calculations were performed for a variety of working fluids for

  4. Proton-coupled electron transfer versus hydrogen atom transfer: generation of charge-localized diabatic states.

    Science.gov (United States)

    Sirjoosingh, Andrew; Hammes-Schiffer, Sharon

    2011-03-24

    The distinction between proton-coupled electron transfer (PCET) and hydrogen atom transfer (HAT) mechanisms is important for the characterization of many chemical and biological processes. PCET and HAT mechanisms can be differentiated in terms of electronically nonadiabatic and adiabatic proton transfer, respectively. In this paper, quantitative diagnostics to evaluate the degree of electron-proton nonadiabaticity are presented. Moreover, the connection between the degree of electron-proton nonadiabaticity and the physical characteristics distinguishing PCET from HAT, namely, the extent of electronic charge redistribution, is clarified. In addition, a rigorous diabatization scheme for transforming the adiabatic electronic states into charge-localized diabatic states for PCET reactions is presented. These diabatic states are constructed to ensure that the first-order nonadiabatic couplings with respect to the one-dimensional transferring hydrogen coordinate vanish exactly. Application of these approaches to the phenoxyl-phenol and benzyl-toluene systems characterizes the former as PCET and the latter as HAT. The diabatic states generated for the phenoxyl-phenol system possess physically meaningful, localized electronic charge distributions that are relatively invariant along the hydrogen coordinate. These diabatic electronic states can be combined with the associated proton vibrational states to generate the reactant and product electron-proton vibronic states that form the basis of nonadiabatic PCET theories. Furthermore, these vibronic states and the corresponding vibronic couplings may be used to calculate rate constants and kinetic isotope effects of PCET reactions.

  5. Ultrahigh figure-of-merit for hydrogen generation from sodium borohydride using ternary metal catalysts

    Science.gov (United States)

    Hu, Lunghao; Ceccato, R.; Raj, R.

    We report further increase in the figure-of-merit (FOM) for hydrogen generation from NaBH 4 than reported in an earlier paper [1], where a sub-nanometer layer of metal catalysts are deposited on carbon nanotube paper (CNT paper) that has been functionalized with polymer-derived silicon carbonitride (SiCN) ceramic film. Ternary, Ru-Pd-Pt, instead of the binary Pd-Pt catalyst used earlier, together with a thinner CNT paper is shown to increase the figure-of-merit by up to a factor of six, putting is above any other known catalyst for hydrogen generation from NaBH 4. The catalysts are prepared by first impregnating the functionalized CNT-paper with solutions of the metal salts, followed by reduction in a sodium borohydride solution. The reaction mechanism and the catalyst efficiency are described in terms of an electric charge transfer, whereby the negative charge on the BH 4 - ion is exchanged with hydrogen via the electronically conducting SiCN/CNT substrate [1].

  6. Assessment of Hydrogen Generation Potential from Biomass and its Application for Power Generation in Andaman and Nicobar Islands: A Review

    Directory of Open Access Journals (Sweden)

    Vinaya C. Mathad

    2016-09-01

    Full Text Available The Andaman and Nicobar Islands located southeast of Bay of Bengal in the Indian Ocean comprises of several small islands separated by sea over large distances which makes it impractical for electrifying all the islands by a single grid. A population of 380,581 (Census, 2011 living in these group of islands get their electricity demand catered through Diesel Generator Sets from 34 power houses with an aggregate capacity of 67.8 MW. Unavailability of any form of conventional fossil fuel reserves in the islands makes the diesel supplied in barges from southeastern coast of India as a sole lifeline for its power generation. Hence there is an urgent need for the development of a self sustainable model from non conventional energy resources to not only cater for the power demands but also to reduce the GHG emissions related with diesel powered generator sets. This paper discusses a self sustainable model for Andaman and Nicobar Islands that would cater the electrical demand through hydrogen produced from waste biomass resource which has a potential of replacing 86.65% of the diesel utilized in the diesel generator sets. The reduction in both the GHG emission and the cost of power generation would be evaluated to understand the impact of the self sustainable model on the environment and the livelihood of the local population of Andaman and Nicobar Islands

  7. Hybrid biomass-wind power plant for reliable energy generation

    International Nuclear Information System (INIS)

    Perez-Navarro, A.; Alfonso, D.; Alvarez, C.; Ibanez, F.; Sanchez, C.; Segura, I.

    2010-01-01

    Massive implementation of renewable energy resources is a key element to reduce CO 2 emissions associated to electricity generation. Wind resources can provide an important alternative to conventional electricity generation mainly based on fossil fuels. However, wind generators are greatly affected by the restrictive operating rules of electricity markets because, as wind is naturally variable, wind generators may have serious difficulties on submitting accurate generation schedules on a day ahead basis, and on complying with scheduled obligations in real-time operation. In this paper, an innovative system combining a biomass gasification power plant, a gas storage system and stand-by generators to stabilize a generic 40 MW wind park is proposed and evaluated with real data. The wind park power production model is based on real data about power production of a Spanish wind park and a probabilistic approach to quantify fluctuations and so, power compensation needs. The hybrid wind-biomass system is analysed to obtain main hybrid system design parameters. This hybrid system can mitigate wind prediction errors and so provide a predictable source of electricity. An entire year cycle of hourly power compensations needs has been simulated deducing storage capacity, extra power needs of the biomass power plant and stand-by generation capacity to assure power compensation during critical peak hours with acceptable reliability. (author)

  8. Hydrogen

    Directory of Open Access Journals (Sweden)

    John O’M. Bockris

    2011-11-01

    Full Text Available The idea of a “Hydrogen Economy” is that carbon containing fuels should be replaced by hydrogen, thus eliminating air pollution and growth of CO2 in the atmosphere. However, storage of a gas, its transport and reconversion to electricity doubles the cost of H2 from the electrolyzer. Methanol made with CO2 from the atmosphere is a zero carbon fuel created from inexhaustible components from the atmosphere. Extensive work on the splitting of water by bacteria shows that if wastes are used as the origin of feed for certain bacteria, the cost for hydrogen becomes lower than any yet known. The first creation of hydrogen and electricity from light was carried out in 1976 by Ohashi et al. at Flinders University in Australia. Improvements in knowledge of the structure of the semiconductor-solution system used in a solar breakdown of water has led to the discovery of surface states which take part in giving rise to hydrogen (Khan. Photoelectrocatalysis made a ten times increase in the efficiency of the photo production of hydrogen from water. The use of two electrode cells; p and n semiconductors respectively, was first introduced by Uosaki in 1978. Most photoanodes decompose during the photoelectrolysis. To avoid this, it has been necessary to create a transparent shield between the semiconductor and its electronic properties and the solution. In this way, 8.5% at 25 °C and 9.5% at 50 °C has been reached in the photo dissociation of water (GaP and InAs by Kainthla and Barbara Zeleney in 1989. A large consortium has been funded by the US government at the California Institute of Technology under the direction of Nathan Lewis. The decomposition of water by light is the main aim of this group. Whether light will be the origin of the post fossil fuel supply of energy may be questionable, but the maximum program in this direction is likely to come from Cal. Tech.

  9. Electro-catalytic conversion of ethanol in solid electrolyte cells for distributed hydrogen generation

    International Nuclear Information System (INIS)

    Ju, HyungKuk; Giddey, Sarbjit; Badwal, Sukhvinder P.S.; Mulder, Roger J.

    2016-01-01

    Highlights: • Ethanol assisted water electrolysis reduces electric energy input by more than 50%. • Partial oxidation of ethanol leads to formation of undesired chemicals. • Degradation occurs due to formation of by-products and poisoning of catalyst. • Better catalyst has the potential to increase ethanol to H_2 conversion efficiency. • A plausible ethanol electro-oxidation mechanism has been proposed - Abstract: The global interest in hydrogen/fuel cell systems for distributed power generation and transport applications is rapidly increasing. Many automotive companies are now bringing their pre-commercial fuel cell vehicles in the market, which will need extensive hydrogen generation, distribution and storage infrastructure for fueling of these vehicles. Electrolytic water splitting coupled to renewable sources offers clean on-site hydrogen generation option. However, the process is energy intensive requiring electric energy >4.2 kWh for the electrolysis stack and >6 kWh for the complete system per m"3 of hydrogen produced. This paper investigates using ethanol as a renewable fuel to assist with water electrolysis process to substantially reduce the energy input. A zero-gap cell consisting of polymer electrolyte membrane electrolytic cells with Pt/C and PtSn/C as anode catalysts were employed. Current densities up to 200 mA cm"−"2 at 70 °C were achieved at less than 0.75 V corresponding to an energy consumption of about 1.62 kWh m"−"3 compared with >4.2 kWh m"−"3 required for conventional water electrolysis. Thus, this approach for hydrogen generation has the potential to substantially reduce the electric energy input to less than 40% with the remaining energy provided by ethanol. However, due to performance degradation over time, the energy consumption increased and partial oxidation of ethanol led to lower conversion efficiency. A plausible ethanol electro-oxidation mechanism has been proposed based on the Faradaic conversion of ethanol and

  10. Comparison of hydrogen generation for TVSM and TVSA fuel assemblies for water water energy reactor (VVER)-1000

    International Nuclear Information System (INIS)

    Stefanova, A.E.; Groudev, P.P.; Atanasova, B.P.

    2009-01-01

    This paper presents the results received during investigation of hydrogen generation for both types fuel assemblies-the old modernistic type of fuel assemblies (TVSM) and recently installed new one alternative type of fuel assemblies (TVSA) in case of severe accident. There are some differences between both types FAs. They have different geometry as well as different burnable poisons. To investigate behavior of new fuel assemblies during the severe conditions it have been performed comparison of fuel behavior of old type TVSM fuel assembly to new one TVSA. To perform this investigation it has been used MELCOR 'input model' for Kozloduy Nuclear Power Plant (KNPP) VVER 1000. The model was developed by Institute for Nuclear Research and Nuclear Energy-Bulgarian Academy of Sciences (INRNE-BAS) for investigation of severe accident scenarios and Probabilistic Safety Analyses (PSA) level 2. The model provides a significant analytical capability for the Bulgarian technical specialists, working in the field of the NPP safety, for analysis of core and containment damaged states and the estimation of radionuclides release outside fuel cladding. It was accepted criteria for vessel integrity about hydrogen concentration to be 8%. This criterion was based on the decision of RSK (Germany commission for reactor safety). Generally based on the received results it was made conclusion that using both types of fuel assemblies it was not disturbance safety conditions of NPP

  11. On-site SiH4 generator using hydrogen plasma generated in slit-type narrow gap

    Science.gov (United States)

    Takei, Norihisa; Shinoda, Fumiya; Kakiuchi, Hiroaki; Yasutake, Kiyoshi; Ohmi, Hiromasa

    2018-06-01

    We have been developing an on-site silane (SiH4) generator based on use of the chemical etching reaction between solid silicon (Si) and the high-density H atoms that are generated in high-pressure H2 plasma. In this study, we have developed a slit-type plasma source for high-efficiency SiH4 generation. High-density H2 plasma was generated in a narrow slit-type discharge gap using a 2.45 GHz microwave power supply. The plasma’s optical emission intensity distribution along the slit was measured and the resulting distribution was reflected by both the electric power distribution and the hydrogen gas flow. Because the Si etching rate strongly affects the SiH4 generation rate, the Si etching behavior was investigated with respect to variations in the experimental parameters. The weight etch rate increased monotonically with increasing input microwave power. However, the weight etch rate decreased with increasing H2 pressure and an increasing plasma gap. This reduction in the etch rate appears to be related to shrinkage of the plasma generation area because increased input power is required to maintain a constant plasma area with increasing H2 pressure and the increasing plasma gap. Additionally, the weight etch rate also increases with increasing H2 flow rate. The SiH4 generation rate of the slit-type plasma source was also evaluated using gas-phase Fourier transform infrared absorption spectroscopy and the material utilization efficiencies of both Si and the H2 gas for SiH4 gas formation were discussed. The main etch product was determined to be SiH4 and the developed plasma source achieved a SiH4 generation rate of 10 sccm (standard cubic centimeters per minute) at an input power of 900 W. In addition, the Si utilization efficiency exceeded 60%.

  12. Artificial earthquake generation for nuclear power plant design

    International Nuclear Information System (INIS)

    King, A.C.Y.; Chen, C.

    1977-01-01

    The time history method has been one of the analytical tools applied in the seismic resistant design of nuclear power plants. The time histories used are required to be consistent with the specified design Spectra. Since the spectra of recorded strong motion earthquake or conventionally generated artificial time history have local peaks and valleys, iteration procedures must be applied to generate the artificial time history with desired spectra. The paper describes a detailed method for generating a time history which is consistent with a specified design spectra. There are several advantages of this method described herein. First of all, frequency content of the time history is well under control. Secondly, if one wishes to generate the three components of an earthquake at one site, the inherent nature of this method will make the correlations among these three components to simulate closely the actual recorded time histories. Thirdly, a single time history can be generated to match a spectra for different damping values. (auth.)

  13. Steam generator assessment for sustainable power plant operation

    International Nuclear Information System (INIS)

    Drexler, Andreas; Fandrich, Joerg; Ramminger, Ute; Montaner-Garcia, Violeta

    2012-09-01

    Water and steam serve in the water-steam cycle as the energy transport and work media. These fluids shall not affect, through corrosion processes on the construction materials and their consequences, undisturbed plant operation. The main objectives of the steam water cycle chemistry consequently are: - The metal release rates of the structural materials shall be minimal - The probability of selective / localized forms of corrosion shall be minimal. - The deposition of corrosion products on heat transfer surfaces shall be minimized. - The formation of aggressive media, particularly local aggressive environments under deposits, shall be avoided. These objectives are especially important for the steam generators (SGs) because their condition is a key factor for plant performance, high plant availability, life time extension and is important to NPP safety. The major opponent to that is corrosion and fouling of the heating tubes. Effective ways of counteracting all degradation problems and thus of improving the SG performance are to keep SGs in clean conditions or if necessary to plan cleaning measures such as mechanical tube sheet lancing or chemical cleaning. Based on more than 40 years of experience in steam-water cycle water chemistry treatment AREVA developed an overall methodology assessing the steam generator cleanliness condition by evaluating all available operational and inspection data together. In order to gain a complete picture all relevant water chemistry data (e.g. corrosion product mass balances, impurity ingress), inspection data (e.g. visual inspections and tube sheet lancing results) and thermal performance data (e.g. heat transfer calculations) are evaluated, structured and indexed using the AREVA Fouling Index Tool Box. This Fouling Index Tool Box is more than a database or statistical approach for assessment of plant chemistry data. Furthermore the AREVA's approach combines manufacturer's experience with plant data and operates with an

  14. Mitigation of Hydrogen Gas Generation from the Reaction of Water with Uranium Metal in K Basins Sludge

    International Nuclear Information System (INIS)

    Sinkov, Sergey I.; Delegard, Calvin H.; Schmidt, Andrew J.

    2010-01-01

    Means to decrease the rate of hydrogen gas generation from the chemical reaction of uranium metal with water were identified by surveying the technical literature. The underlying chemistry and potential side reactions were explored by conducting 61 principal experiments. Several methods achieved significant hydrogen gas generation rate mitigation. Gas-generating side reactions from interactions of organics or sludge constituents with mitigating agents were observed. Further testing is recommended to develop deeper knowledge of the underlying chemistry and to advance the technology aturation level. Uranium metal reacts with water in K Basin sludge to form uranium hydride (UH3), uranium dioxide or uraninite (UO2), and diatomic hydrogen (H2). Mechanistic studies show that hydrogen radicals (H·) and UH3 serve as intermediates in the reaction of uranium metal with water to produce H2 and UO2. Because H2 is flammable, its release into the gas phase above K Basin sludge during sludge storage, processing, immobilization, shipment, and disposal is a concern to the safety of those operations. Findings from the technical literature and from experimental investigations with simple chemical systems (including uranium metal in water), in the presence of individual sludge simulant components, with complete sludge simulants, and with actual K Basin sludge are presented in this report. Based on the literature review and intermediate lab test results, sodium nitrate, sodium nitrite, Nochar Acid Bond N960, disodium hydrogen phosphate, and hexavalent uranium [U(VI)] were tested for their effects in decreasing the rate of hydrogen generation from the reaction of uranium metal with water. Nitrate and nitrite each were effective, decreasing hydrogen generation rates in actual sludge by factors of about 100 to 1000 when used at 0.5 molar (M) concentrations. Higher attenuation factors were achieved in tests with aqueous solutions alone. Nochar N960, a water sorbent, decreased hydrogen

  15. Mitigation of Hydrogen Gas Generation from the Reaction of Water with Uranium Metal in K Basins Sludge

    Energy Technology Data Exchange (ETDEWEB)

    Sinkov, Sergey I.; Delegard, Calvin H.; Schmidt, Andrew J.

    2010-01-29

    Means to decrease the rate of hydrogen gas generation from the chemical reaction of uranium metal with water were identified by surveying the technical literature. The underlying chemistry and potential side reactions were explored by conducting 61 principal experiments. Several methods achieved significant hydrogen gas generation rate mitigation. Gas-generating side reactions from interactions of organics or sludge constituents with mitigating agents were observed. Further testing is recommended to develop deeper knowledge of the underlying chemistry and to advance the technology aturation level. Uranium metal reacts with water in K Basin sludge to form uranium hydride (UH3), uranium dioxide or uraninite (UO2), and diatomic hydrogen (H2). Mechanistic studies show that hydrogen radicals (H·) and UH3 serve as intermediates in the reaction of uranium metal with water to produce H2 and UO2. Because H2 is flammable, its release into the gas phase above K Basin sludge during sludge storage, processing, immobilization, shipment, and disposal is a concern to the safety of those operations. Findings from the technical literature and from experimental investigations with simple chemical systems (including uranium metal in water), in the presence of individual sludge simulant components, with complete sludge simulants, and with actual K Basin sludge are presented in this report. Based on the literature review and intermediate lab test results, sodium nitrate, sodium nitrite, Nochar Acid Bond N960, disodium hydrogen phosphate, and hexavalent uranium [U(VI)] were tested for their effects in decreasing the rate of hydrogen generation from the reaction of uranium metal with water. Nitrate and nitrite each were effective, decreasing hydrogen generation rates in actual sludge by factors of about 100 to 1000 when used at 0.5 molar (M) concentrations. Higher attenuation factors were achieved in tests with aqueous solutions alone. Nochar N960, a water sorbent, decreased hydrogen

  16. Hydrogen sensor

    Science.gov (United States)

    Duan, Yixiang; Jia, Quanxi; Cao, Wenqing

    2010-11-23

    A hydrogen sensor for detecting/quantitating hydrogen and hydrogen isotopes includes a sampling line and a microplasma generator that excites hydrogen from a gas sample and produces light emission from excited hydrogen. A power supply provides power to the microplasma generator, and a spectrometer generates an emission spectrum from the light emission. A programmable computer is adapted for determining whether or not the gas sample includes hydrogen, and for quantitating the amount of hydrogen and/or hydrogen isotopes are present in the gas sample.

  17. Intracellular signaling by diffusion: can waves of hydrogen peroxide transmit intracellular information in plant cells?

    DEFF Research Database (Denmark)

    Vestergaard, Christian L.; Flyvbjerg, Henrik; Møller, Ian Max

    2012-01-01

    of the physical and biochemical conditions in plant cells. As model system, we use a H(2)O(2) signal originating at the plasma membrane (PM) and spreading through the cytosol. We consider two maximally simple types of signals, isolated pulses and harmonic oscillations. First we consider the basic limits......Amplitude- and frequency-modulated waves of Ca(2+) ions transmit information inside cells. Reactive Oxygen Species (ROS), specifically hydrogen peroxide, have been proposed to have a similar role in plant cells. We consider the feasibility of such an intracellular communication system in view...

  18. Prototype CIRCE plant-industrial demonstration of heavy-water production from a reformed hydrogen source

    Energy Technology Data Exchange (ETDEWEB)

    Spagnolo, D.A.; Boniface, H.A.; Sadhankar, R.R.; Everatt, A.E.; Miller, A.I. [Atomic Energy of Canada Limited, Chalk River, Ontario (Canada); Blouin, J. [Air Liquide Canada, Hamilton, Ontario (Canada)

    2002-09-01

    Heavy-water (D{sub 2}0) production has been dominated by the Girdler-Sulphide (G-S) process, which suffers several intrinsic disadvantages that lead to high production costs. Processes based on hydrogen/water exchange have become more attractive with the development of proprietary wetproofed catalysts by AECL. One process that is synergistic with industrial hydrogen production by steam methane reforming (SMR), the combined industrial reforming and catalytic exchange (CIRCE) process, offers the best prospect for commercialization. SMRs are common globally in the oil upgrading and ammonia industries. To study the CIRCE process in detail, AECL, in collaboration with Air Liquide Canada, constructed a prototype CIRCE plant (PCP) in Hamilton, ON. The plant became fully operational in 2000 July and is expected to operate to at least the late fall of 2002. To date, plant operation has confirmed the adequacy of the design and the capability of enriching deuterium to produce heavy water without compromising hydrogen production. The proprietary wetproofed catalyst has performed as expected, both in activity and in robustness. (author)

  19. Scenarios for multi-unit inertial fusion energy plants producing hydrogen fuel

    International Nuclear Information System (INIS)

    Logan, B.G.

    1993-12-01

    This work describes: (a) the motivation for considering fusion in general, and Inertial Fusion Energy (IFE) in particular, to produce hydrogen fuel powering low-emission vehicles; (b) the general requirements for any fusion electric plant to produce hydrogen by water electrolysis at costs competitive with present consumer gasoline fuel costs per passenger mile, for advanced car architectures meeting President Clinton's 80 mpg advanced car goal, and (c) a comparative economic analysis for the potential cost of electricity (CoE) and corresponding cost of hydrogen (CoH) from a variety of multi-unit IFE plants with one to eight target chambers sharing a common driver and target fab facility. Cases with either heavy-ion or diode-pumped, solid-state laser drivers are considered, with ''conventional'' indirect drive target gains versus ''advanced, e.g. Fast Ignitor'' direct drive gain assumptions, and with conventional steam balance-of-plant (BoP) versus advanced MHD plus steam combined cycle BoP, to contrast the potential economics under ''conventional'' and ''advanced'' IFE assumptions, respectively

  20. Mathematical model for solar-hydrogen heated desalination plant using humidification-dehumidification process

    International Nuclear Information System (INIS)

    Yassin, Jamal S.; Eljrushi, Gibril S.

    2006-01-01

    This paper presents a mathematical model for thermal desalination plant operating with solar energy and hydrogen. This plant is composed of two main systems, the heating system and the distillation system. The distillation system is composed of multi-cells; each cell is using the humidification-dehumidification (H-D) process in the distillation unit and getting the required amount of heat from feed seawater heater. The feed seawater heater is a heat exchanger used to raise the temperature of the preheated seawater coming from the condensation chamber (Dehumidifier) of each cell to about 85 degree centigrade. The heating amount in the heat exchangers is obtained from the thermal storage tank, which gets its energy from solar thermal system and is coupled with a hydrogen-fired backup system to guaranty necessary operating conditions and permit 24 hours solar H-D desalination plant to enhance the performance of this system. The mathematical model studies the performance of the proposed desalination system using thermal solar energy and hydrogen as fuel. Other pertinent variable in the heating and distillation system are also studied. The outcomes of this study are analyzed to enhance the used solar desalination process and make commercial.(Author)

  1. Prototype CIRCE plant-industrial demonstration of heavy-water production from a reformed hydrogen source

    International Nuclear Information System (INIS)

    Spagnolo, D.A.; Boniface, H.A.; Sadhankar, R.R.; Everatt, A.E.; Miller, A.I.; Blouin, J.

    2002-09-01

    Heavy-water (D 2 0) production has been dominated by the Girdler-Sulphide (G-S) process, which suffers several intrinsic disadvantages that lead to high production costs. Processes based on hydrogen/water exchange have become more attractive with the development of proprietary wetproofed catalysts by AECL. One process that is synergistic with industrial hydrogen production by steam methane reforming (SMR), the combined industrial reforming and catalytic exchange (CIRCE) process, offers the best prospect for commercialization. SMRs are common globally in the oil upgrading and ammonia industries. To study the CIRCE process in detail, AECL, in collaboration with Air Liquide Canada, constructed a prototype CIRCE plant (PCP) in Hamilton, ON. The plant became fully operational in 2000 July and is expected to operate to at least the late fall of 2002. To date, plant operation has confirmed the adequacy of the design and the capability of enriching deuterium to produce heavy water without compromising hydrogen production. The proprietary wetproofed catalyst has performed as expected, both in activity and in robustness. (author)

  2. Prototype CIRCE plant - industrial demonstration of heavy water production from reformed hydrogen source

    International Nuclear Information System (INIS)

    Spagnolo, D.A.; Boniface, H.A.; Sadhankar, R.R.; Everatt, A.E.; Miller, A.I.; Blouin, J.

    2002-01-01

    Heavy water (D 2 0) production has been dominated by the Girdler-Sulphide (G-S) process, which suffers several intrinsic disadvantages that lead to high production costs. Processes based on hydrogen/water exchange have become more attractive with the development of proprietary wetproofed catalysts by AECL. One process that is synergistic with industrial hydrogen production by steam methane reforming (SMR), the Combined Industrial Reforming and Catalytic Exchange (CIRCE) process, offers the best prospect for commercialization. SMRs are common globally in the oil-upgrading and ammonia industries. To study the CIRCE process in detail, AECL, in collaboration with Air Liquide Canada, constructed a prototype CIRCE plant (PCP) in Hamilton, Ontario. The plant became fully operational in 2000 July and is expected to operate to at least late fall of 2002. To-date, plant operation has confirmed the adequacy of the design and the capability of enriching deuterium to produce heavy water without compromising hydrogen production. The proprietary wetproofed catalyst has performed as expected, both in activity and in robustness. (author)

  3. Photocatalyst based on titanium or iron semiconductors for the generation of hydrogen from water upon solar irradiation

    OpenAIRE

    Serra, Marco

    2016-01-01

    The objective of present thesis is to prepare and evaluate photocatalyst for hydrogen generation from water methanol mixture using solar light. This general objective has been accomplished by applying different methodology in material preparation as well as exploring the photocatalytic activity of novel semiconductors. In this way after a general introduction to the feed showing the relevance of solar fuels and in particular hydrogen generation, the...

  4. Financial Benefits of Process Data Reconciliation in Power Generating Plants

    International Nuclear Information System (INIS)

    Jansky, Andy

    2006-01-01

    Process Data Reconciliation (PDR) is a certified method that calculates the most likely values considering process measurement uncertainties and closing all energy- and material balances where all inter-dependencies within the entire plant process are fulfilled in a covariance matrix. There are three main factors that generate the financial benefits for the user of reconciled data, depending on the type of plant and base/peak load behaviour: Increased efficiency / maximized output, Time advantage in retrieving 'lost' megawatts, Reduction of maintenance costs. (author)

  5. Computer functions in overall plant control of candu generating stations

    International Nuclear Information System (INIS)

    Chou, Q.B.; Stokes, H.W.

    1976-01-01

    System Planning Specifications form the basic requirements for the performance of the plant including its response to abnormal situations. The rules for the computer control programs are devised from these, taking into account limitations imposed by the reactor, heat transport and turbine-generator systems. The paper outlines these specifications and the limitations imposed by the major items of plant equipment. It describes the functions of each of the main programs, their interactions and the control modes used in the existing Ontario Hydro's nuclear station or proposed for future stations. Some simulation results showing the performance of the overall unit control system and plans for future studies are discussed. (orig.) [de

  6. Comparison of hydrogen production and electrical power generation for energy capture in closed-loop ammonium bicarbonate reverse electrodialysis systems.

    Science.gov (United States)

    Hatzell, Marta C; Ivanov, Ivan; Cusick, Roland D; Zhu, Xiuping; Logan, Bruce E

    2014-01-28

    Currently, there is an enormous amount of energy available from salinity gradients, which could be used for clean hydrogen production. Through the use of a favorable oxygen reduction reaction (ORR) cathode, the projected electrical energy generated by a single pass ammonium bicarbonate reverse electrodialysis (RED) system approached 78 W h m(-3). However, if RED is operated with the less favorable (higher overpotential) hydrogen evolution electrode and hydrogen gas is harvested, the energy recovered increases by as much ~1.5× to 118 W h m(-3). Indirect hydrogen production through coupling an RED stack with an external electrolysis system was only projected to achieve 35 W h m(-3) or ~1/3 of that produced through direct hydrogen generation.

  7. Comparison of hydrogen production and electrical power generation for energy capture in closed-loop ammonium bicarbonate reverse electrodialysis systems

    KAUST Repository

    Hatzell, Marta C.; Ivanov, Ivan; D. Cusick, Roland; Zhu, Xiuping; Logan, Bruce E.

    2014-01-01

    Currently, there is an enormous amount of energy available from salinity gradients, which could be used for clean hydrogen production. Through the use of a favorable oxygen reduction reaction (ORR) cathode, the projected electrical energy generated by a single pass ammonium bicarbonate reverse electrodialysis (RED) system approached 78 W h m-3. However, if RED is operated with the less favorable (higher overpotential) hydrogen evolution electrode and hydrogen gas is harvested, the energy recovered increases by as much ∼1.5× to 118 W h m-3. Indirect hydrogen production through coupling an RED stack with an external electrolysis system was only projected to achieve 35 W h m-3 or ∼1/3 of that produced through direct hydrogen generation.

  8. Controllable pneumatic generator based on the catalytic decomposition of hydrogen peroxide

    International Nuclear Information System (INIS)

    Kim, Kyung-Rok; Kim, Kyung-Soo; Kim, Soohyun

    2014-01-01

    This paper presents a novel compact and controllable pneumatic generator that uses hydrogen peroxide decomposition. A fuel micro-injector using a piston-pump mechanism is devised and tested to control the chemical decomposition rate. By controlling the injection rate, the feedback controller maintains the pressure of the gas reservoir at a desired pressure level. Thermodynamic analysis and experiments are performed to demonstrate the feasibility of the proposed pneumatic generator. Using a prototype of the pneumatic generator, it takes 6 s to reach 3.5 bars with a reservoir volume of 200 ml at the room temperature, which is sufficiently rapid and effective to maintain the repetitive lifting of a 1 kg mass

  9. Controllable pneumatic generator based on the catalytic decomposition of hydrogen peroxide

    Science.gov (United States)

    Kim, Kyung-Rok; Kim, Kyung-Soo; Kim, Soohyun

    2014-07-01

    This paper presents a novel compact and controllable pneumatic generator that uses hydrogen peroxide decomposition. A fuel micro-injector using a piston-pump mechanism is devised and tested to control the chemical decomposition rate. By controlling the injection rate, the feedback controller maintains the pressure of the gas reservoir at a desired pressure level. Thermodynamic analysis and experiments are performed to demonstrate the feasibility of the proposed pneumatic generator. Using a prototype of the pneumatic generator, it takes 6 s to reach 3.5 bars with a reservoir volume of 200 ml at the room temperature, which is sufficiently rapid and effective to maintain the repetitive lifting of a 1 kg mass.

  10. SiC Sensors in Extreme Environments: Real-time Hydrogen Monitoring for Energy Plant Applications

    Science.gov (United States)

    Ghosh, Ruby

    2008-03-01

    Clean, efficient energy production, such as the gasification of coal (syngas), requires physical and chemical sensors for exhaust gas monitoring as well as real-time control of the combustion process. Wide-bandgap semiconducting materials systems can meet the sensing demands in these extreme environments consisting of chemically corrosive gases at high temperature and pressure. We have developed a SiC based micro-sensor for detection of hydrogen containing species with millisecond response at 600 C. The sensor is a Pt-SiO2-SiC device with a dense Pt catalytic sensing film, capable of withstanding months of continuous high temperature operation. The device was characterized in robust sensing module that is compatible with an industrial reactor. We report on the performance of the SiC sensor in a simulated syngas ambient at 370 C containing the common interferants CO2, CH4 and CO [1]. In addition we demonstrate that hours of exposure to >=1000 ppm H2S and 15% water vapor does not degrade the sensor performance. To elucidate the mechanisms responsible for the hydrogen response of the sensor we have modeled the hydrogen adsorptions kinetics at the internal Pt-SiO2 interface, using both the Tempkin and Langmuir isotherms. Under the conditions appropriate for energy plant applications, the response of our sensor is significantly larger than that obtained from ultra-high vacuum electrochemical sensor measurements at high temperatures. We will discuss the role of morphology, at the nano to micro scale, on the enhanced catalytic activity observed for our Pt sensing films in response to a heated hydrogen gas stream at atmospheric pressure. [1] R. Loloee, B. Chorpening, S. Beers & R. Ghosh, Hydrogen monitoring for power plant applications using SiC sensors, Sens. Actuators B:Chem. (2007), doi:10.1016/j.snb.2007.07.118

  11. Final Technical Report for GO15056 Millennium Cell: Development of an Advanced Chemical Hydrogen Storage and Generation System

    Energy Technology Data Exchange (ETDEWEB)

    Moreno, Oscar [Millennium Cell Inc., Eatontown, NJ (United States)

    2017-02-22

    The objectives of this project are to increase system storage capacity by improving hydrogen generation from concentrated sodium borohydride, with emphasis on reactor and system engineering; to complete a conceptual system design based on sodium borohydride that will include key technology improvements to enable a hydrogen fuel system that will meet the systembased storage capacity of 1.2 kWh/L (36 g H2/L) and 1.5 kWh/kg (45 g H2/kg), by the end of FY 2007; and to utilize engineering expertise to guide Center research in both off-board chemical hydride regeneration and on-board hydrogen generation systems.

  12. Status and integration of the gas generation studies performed for the Hydrogen Safety Program

    International Nuclear Information System (INIS)

    Pederson, L.R.; Strachan, D.M.

    1993-02-01

    Waste in Tank 241-SY-101 on the Hanford Site generates and periodically releases hydrogen, nitrous oxide, and nitrogen gases. Studies have been conducted at several laboratories to determine the chemical mechanisms for the gas generation and release. Results from these studies are presented and integrated in an attempt to describe current understanding of the physical properties of the waste and the mechanisms of gas generation and retention. Existing tank data are consistent with the interpretation that gases are uniformly generated in the tank, released continuously from the convecting layer, and stored in the nonconvecting layer. Tank temperature measurements suggest that the waste consists of ''gobs'' of material that reach neutral buoyancy at different times. The activation energy of the rate limiting step of the gas generating process was calculated to be about 7 kJ/mol but measured in the laboratory at 80 to 100 kJ/mol. Based on observed temperature changes in the tank the activation energy is probably not higher than about 20 kJ/mol. Several simulated waste compositions have been devised for use in laboratory studies in the place of actual waste from Tank 241-SY-101. Data from these studies can be used to predict how the actual waste might behave when heated or diluted. Density evaluations do not confirm that heating waste at the bottom of the tank would induce circulation within the waste; however, heating may release gas bubbles by dissolving the solids to which the bubbles adhere. Gas generation studies on simulated wastes indicated that nitrous oxide and hydrogen yields are not particularly coupled. Solubility studies of nitrous oxide, the most soluble of the principal gaseous products, indicate it is unlikely that dissolved gases contribute substantially to the quantity of gas released during periodic events

  13. Vitamin K3 triggers human leukemia cell death through hydrogen peroxide generation and histone hyperacetylation.

    Science.gov (United States)

    Lin, Changjun; Kang, Jiuhong; Zheng, Rongliang

    2005-10-01

    Vitamin K3 (VK3) is a well-known anticancer agent, but its mechanism remains elusive. In the present study, VK3 was found to simultaneously induce cell death, reactive oxygen species (ROS) generation, including superoxide anion (O2*-) and hydrogen peroxide (H2O2) generation, and histone hyperacetylation in human leukemia HL-60 cells in a concentration- and time-dependent manner. Catalase (CAT), an antioxidant enzyme that specifically scavenges H2O2, could significantly diminish both histone acetylation increase and cell death caused by VK3, whereas superoxide dismutase (SOD), an enzyme that specifically eliminates O2*-, showed no effect on both of these, leading to the conclusion that H2O2 generation, but not O2*- generation, contributes to VK3-induced histone hyperacetylation and cell death. This conclusion was confirmed by the finding that enhancement of VK3-induced H2O2 generation by vitamin C (VC) could significantly promote both the histone hyperacetylation and cell death. Further studies suggested that histone hyperacetylation played an important role in VK3-induced cell death, since sodium butyrate, a histone deacetylase (HDAC) inhibitor, showed no effect on ROS generation, but obviously potentiated VK3-induced histone hyperacetylation and cell death. Collectively, these results demonstrate a novel mechanism for the anticancer activity of VK3, i.e., VK3 induced tumor cell death through H2O2 generation, which then further induced histone hyperacetylation.

  14. 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.

  15. Integration of direct carbon and hydrogen fuel cells for highly efficient power generation from hydrocarbon fuels

    Energy Technology Data Exchange (ETDEWEB)

    Muradov, Nazim; Choi, Pyoungho; Smith, Franklyn; Bokerman, Gary [Florida Solar Energy Center, University of Central Florida, 1679 Clearlake Road, Cocoa, FL 32922-5703 (United States)

    2010-02-15

    In view of impending depletion of hydrocarbon fuel resources and their negative environmental impact, it is imperative to significantly increase the energy conversion efficiency of hydrocarbon-based power generation systems. The combination of a hydrocarbon decomposition reactor with a direct carbon and hydrogen fuel cells (FC) as a means for a significant increase in chemical-to-electrical energy conversion efficiency is discussed in this paper. The data on development and operation of a thermocatalytic hydrocarbon decomposition reactor and its coupling with a proton exchange membrane FC are presented. The analysis of the integrated power generating system including a hydrocarbon decomposition reactor, direct carbon and hydrogen FC using natural gas and propane as fuels is conducted. It was estimated that overall chemical-to-electrical energy conversion efficiency of the integrated system varied in the range of 49.4-82.5%, depending on the type of fuel and FC used, and CO{sub 2} emission per kW{sub el}h produced is less than half of that from conventional power generation sources. (author)

  16. Enhanced Solar-to-Hydrogen Generation with Broadband Epsilon-Near-Zero Nanostructured Photocatalysts

    KAUST Repository

    Tian, Yi

    2017-05-08

    The direct conversion of solar energy into fuels or feedstock is an attractive approach to address increasing demand of renewable energy sources. Photocatalytic systems relying on the direct photoexcitation of metals have been explored to this end, a strategy that exploits the decay of plasmonic resonances into hot carriers. An efficient hot carrier generation and collection requires, ideally, their generation to be enclosed within few tens of nanometers at the metal interface, but it is challenging to achieve this across the broadband solar spectrum. Here the authors demonstrate a new photocatalyst for hydrogen evolution based on metal epsilon-near-zero metamaterials. The authors have designed these to achieve broadband strong light confinement at the metal interface across the entire solar spectrum. Using electron energy loss spectroscopy, the authors prove that hot carriers are generated in a broadband fashion within 10 nm in this system. The resulting photocatalyst achieves a hydrogen production rate of 9.5 µmol h-1  cm-2 that exceeds, by a factor of 3.2, that of the best previously reported plasmonic-based photocatalysts for the dissociation of H2 with 50 h stable operation.

  17. Improvements in steam cycle electric power generating plants

    International Nuclear Information System (INIS)

    Bienvenu, Claude.

    1973-01-01

    The invention relates to a steam cycle electric energy generating plants of the type comprising a fossil or nuclear fuel boiler for generating steam and a turbo alternator group, the turbine of which is fed by the boiler steam. The improvement is characterized in that use is made of a second energy generating group in which a fluid (e.g. ammoniac) undergoes a condensation cycle the heat source of said cycle being obtained through a direct or indirect heat exchange with a portion of the boiler generated steam whereby it is possible without overloading the turbo-alternator group, to accomodate any increase of the boiler power resulting from the use of another fuel while maintaining a maximum energy output. This can be applied to electric power stations [fr

  18. Effective regimes of runaway electron beam generation in helium, hydrogen, and nitrogen

    Science.gov (United States)

    Tarasenko, V. F.; Baksht, E. Kh.; Burachenko, A. G.; Lomaev, M. I.; Sorokin, D. A.; Shut'ko, Yu. V.

    2010-04-01

    Runaway electron beam parameters and current-voltage characteristics of discharge in helium, hydrogen, and nitrogen at pressures in the range of several Torr to several hundred Torr have been studied. It is found that the maximum amplitudes of supershort avalanche electron beams (SAEBs) with a pulse full width at half maximum (FWHM) of ˜100 ps are achieved in helium, hydrogen, and nitrogen at a pressure of ˜60, ˜30, and ˜10 Torr, respectively. It is shown that, as the gas pressure is increased in the indicated range, the breakdown voltage of the gas-filled gap decreases, which leads to a decrease in the SAEB current amplitude. At pressures of helium within 20-60 Torr, hydrogen within 10-30 Torr, and nitrogen within 3-10 Torr, the regime of the runaway electron beam generation changes and, by varying the pressure in the gas-filled diode in the indicated intervals, it is possible to smoothly control the current pulse duration (FWHM) from ˜100 to ˜500 ps, while the beam current amplitude increases by a factor of 1.5-3.

  19. Hydrolytic hydrogen generation using milled aluminum in water activated by Li, In, and Zn additives

    Energy Technology Data Exchange (ETDEWEB)

    Fan, M.Q.; Liu, S.; Wang, C.; Chen, D.; Shu, K.Y. [Department of Materials Science and Engineering, China Jiliang University, Hangzhou (China)

    2012-08-15

    A method for obtaining hydrogen through the hydrolytic reaction of highly activated aluminum (Al) alloy is investigated. The optimized Al-3 wt.% Li-4 wt.% In-7 wt.% Zn alloy significantly improves the maximum hydrogen generation rate and amount (137 mL g{sup -1} min{sup -1} and 1,243 mL g{sup -1}, respectively). An efficiency of 100% was reached within 1 h at 298 K. The synergistic catalytic effects of Li, In, and Zn, which stimulated Al hydrolysis through the formation of micro galvanic cells of In-Li and Al-In-Zn alloys in water, were observed. The reactions were analyzed using X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and hydrolytic experiments. The In-Li alloy functions as an initial active center and produces LiOH in water, which further stimulates and changes the hydrolytic process of the Al-In-Zn alloy. The effects of alloy composition, milling time, and hydrolytic temperature were considered and discussed. The results indicate that the hydrolytic reaction of Al-Li-In-Zn alloy in water might be feasible for the production of inexpensive, pure, and safe hydrogen for micro fuel cells. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  20. Photo-electrocatalytic hydrogen generation at dye-sensitised electrodes functionalised with a heterogeneous metal catalyst

    International Nuclear Information System (INIS)

    Hoogeveen, Dijon A.; Fournier, Maxime; Bonke, Shannon A.; Fang, Xi-Ya; Mozer, Attila J.; Mishra, Amaresh; Bäuerle, Peter; Simonov, Alexandr N.; Spiccia, Leone

    2016-01-01

    Dye-sensitised photocathodes promoting hydrogen evolution are usually coupled to a catalyst to improve the reaction rate. Herein, we report on the first successful integration of a heterogeneous metal particulate catalyst, viz., Pt aggregates electrodeposited from acidic solutions on the surface of a NiO-based photocathode sensitised with a p-type perylenemonoimid-sexithiophene-triphenylamine dye (PMI-6T-TPA). The platinised dye-NiO electrodes generate photocurrent density of ca −0.03 mA cm −2 (geom.) with 100% faradaic efficiency for the H 2 evolution at 0.059 V vs. reversible hydrogen electrode under 1 sun visible light irradiation (AM1.5G, 100 mW cm −2 , λ > 400 nm) for more than 10 hours in 0.1 M H 2 SO 4 (aq.). The Pt-free dye-NiO and dye-free Pt-modified NiO cathodes show no photo-electrocatalytic hydrogen evolution under these conditions. The performance of these Pt-modified PMI-6T-TPA-based photoelectrodes compares well to that of previously reported dye-sensitised photocathodes for H 2 evolution.

  1. Auto generation plant of Artigas landfill (Bilbao, Spain)

    International Nuclear Information System (INIS)

    Carreras, N.; Dorronsoro, J.L.

    1996-01-01

    The disposition of MSW in the landfill generates a mixture of gases or b iogas , its primary content is methane (50-60%) which has a very important energetic value, that can be very useful. In this sense, the present work point out the characteristics of the auto generation electrical plant of Artigas landfill, just like the results of the analytical study of the past two years. In this project which was partly funded by the UE, have participated Excmo. Ayuntamiento de Bilbao, EVE and CIEMAT. (Author) 6 refs

  2. Steam generator design considerations for modular HTGR plant

    International Nuclear Information System (INIS)

    McDonald, C.F.; DeFur, D.D.

    1986-01-01

    Studies are in progress to develop a standard High Temperature Gas-Cooled Reactor (HTGR) plant design that is amenable to serial production and is licensable. Based on the results of trade studies performed in the DOE-funded HTGR program, activities are being focused to emphasize a modular concept based on a 350 MW(t) annular reactor core with prismatic fuel elements. Utilization of a multiplicity of the standard module affords flexibility in power rating for utility electricity generation. The selected modular HTGR concept has the reactor core and heat transport systems housed in separate steel vessels. This paper highlights the steam generator design considerations for the reference plant, and includes a discussion of the major features of the heat exchanger concept and the technology base existing in the U.S

  3. Radiofrequency radiation exposure from RF-generating plant

    International Nuclear Information System (INIS)

    Wright, J.M.; Bell, K.M.

    2000-01-01

    As part of an intervention to assist industry improve the control of risks associated with the use of RF-generating plant, exposure to radiofrequency radiation (RFR) was assessed in 30 workplaces. Information about the workplace, work practices and knowledge about RFR and its control was also collected. The study found that: 1. For 72% of operators and 35% of bystanders, the spatially averaged exposure exceeded the exposure limits. These figures approximately halved when the duty cycle was applied; 2. Assessment of RFR levels was not common; 3. Task rotation was used to limit exposure of operators; 4. Access was not controlled to areas where RFR sources were used; 5. There was lack of knowledge about RF shielding practices in industry; 6. Nearly 50% of workplaces did not maintain the plant regularly; and 7. There had been no health surveillance on any plant operators in any of the workplaces in the study. Copyright (2000) Australasian Radiation Protection Society Inc

  4. Large photovoltages generated by plant photosystem I crystals

    Energy Technology Data Exchange (ETDEWEB)

    Toporik, Hila; Carmeli, Chanoch; Nelson, Nathan [Department of Biochemistry and Molecular Biology, Faculty of Life Sciences, Tel Aviv University, Tel Aviv 69978 (Israel); Carmeli, Itai [School of Chemistry, Faculty of Exact Sciences, Tel Aviv University, Tel Aviv 69978 (Israel); Volotsenko, Irina; Molotskii, Michel; Rosenwaks, Yossi [Department of Physical Electronics, Faculty of Engineering, Tel Aviv University, Tel Aviv 69978 (Israel)

    2012-06-12

    Micrometer-thick plant photosystem I crystals made of up to 1000 layers of serially arranged protein complexes generate unprecedented high photovoltages when placed on a conducting solid surface and measured using Kelvin probe force microscopy. The successive layers form serially photoinduced dipoles in the crystal that give rise to electric fields as large as 100 kV cm{sup -1}. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  5. Hydrogen Generation from Biomass-Derived Surgar Alcohols via the Aqueous-Phase Carbohydrate Reforming (ACR) Process

    Energy Technology Data Exchange (ETDEWEB)

    Randy Cortright

    2006-06-30

    This project involved the investigation and development of catalysts and reactor systems that will be cost-effective to generate hydrogen from potential sorbitol streams. The intention was to identify the required catalysts and reactors systems as well as the design, construction, and operation of a 300 grams per hour hydrogen system. Virent was able to accomplish this objective with a system that generates 2.2 kgs an hour of gas containing both hydrogen and alkanes that relied directly on the work performed under this grant. This system, funded in part by the local Madison utility, Madison, Gas & Electric (MGE), is described further in the report. The design and development of this system should provide the necessary scale-up information for the generation of hydrogen from corn-derived sorbitol.

  6. 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

  7. Hydrogen sulfide generation in simulated construction and demolition debris landfills: impact of waste composition.

    Science.gov (United States)

    Yang, Kenton; Xu, Qiyong; Townsend, Timothy G; Chadik, Paul; Bitton, Gabriel; Booth, Matthew

    2006-08-01

    Hydrogen sulfide (H2S) generation in construction and demolition (C&D) debris landfills has been associated with the biodegradation of gypsum drywall. Laboratory research was conducted to observe H2S generation when drywall was codisposed with different C&D debris constituents. Two experiments were conducted using simulated landfill columns. Experiment 1 consisted of various combinations of drywall, wood, and concrete to determine the impact of different waste constituents and combinations on H2S generation. Experiment 2 was designed to examine the effect of concrete on H2S generation and migration. The results indicate that decaying drywall, even alone, leached enough sulfate ions and organic matter for sulfate-reducing bacteria (SRB) to generate large H2S concentrations as high as 63,000 ppmv. The codisposed wastes show some effect on H2S generation. At the end of experiment 1, the wood/drywall and drywall alone columns possessed H2S concentrations > 40,000 ppmv. Conversely, H2S concentrations were debris landfills are suggested.

  8. Dibenzazepin hydrochloride as a new spectrophotometric reagent for determination of hydrogen peroxide in plant extracts.

    Science.gov (United States)

    Nagaraja, P; Prakash, J S; Asha, S C; Bhaskara, B L; Kumar, S Anil

    2012-10-01

    A rapid, simple, accurate, and sensitive visible spectrophotometric method for the determination of trace amounts of hydrogen peroxide in acidic buffer medium is reported. The proposed method is based on the oxidative coupling of Ampyrone with dibenzazepin hydrochloride by hydrogen peroxide in the buffer medium of pH 4.0 which is catalyzed by ferrous iron. The blue-colored product formed with maximum absorption at 620 nm was found to be stable for 2 h. Beer's law is obeyed for hydrogen peroxide concentration in the range of 0.03-0.42 μg ml(-1). The optimum reaction conditions and other important optical parameters are reported. The molar absorptive and Sandell's sensitivity are found to be 5.89 × 10(4) mol(-1) cm(-1) and 0.57 g/cm(2), respectively. The interference due to diverse ions and complexing agents was studied. The method is successfully applied to the determination of hydrogen peroxide in green plants satisfactorily.

  9. Pre elementary design of primary reformer for hydrogen plant coupled with HTGR type NPP

    International Nuclear Information System (INIS)

    Dedy Priambodo; Erlan Dewita; Sudi Ariyanto

    2012-01-01

    Hydrogen has a high potent for new energy, because of it availability. Steam reforming is a fully developed commercial technology and is the most economical method for production of hydrogen. Steam reforming uses an external source of hot gas to heat tubes in which a catalytic reaction takes place that converts steam and lighter hydrocarbons such as natural gas (methane) or refinery feedstock into hydrogen and carbon monoxide (syngas) at high temperature on primary reformer (800-900°C). Utilization of helium from HTGR as heating medium for primary reformer has consequence to type and shape of its reactor. The main goal of this paper is to determine type/shape and pre elementary design of chemical reactor for the cogeneration system of Hydrogen Plant and HTGR The primary reformer for this system is Fixed Bed Multitube reactor with specification tube: NPS 3,5 Sch 40 ST 40S, 0.281 in thickness, number of tube 849 pieces and ASTM HH 30 for tube material. Tube arrangement is 'triangular pitch' on shell Split-Ring Floating Head from Steel Alloy SA 301 Grade B equipted with 8 baffles. (author)

  10. Exergy analysis for Generation IV nuclear plant optimization

    International Nuclear Information System (INIS)

    Gomez, A.; Azzaro-Pantel, C.; Domenech, S.; Pibouleau, L.; Latge, Ch.; Haubensack, D.; Dumaz, P.

    2010-01-01

    This paper deals with the application of the exergy concept to an energy production system involving a very high temperature reactor coupled with an innovative electricity-generating cycle. The objective is to propose a general approach to quantify exergy destruction of the involved process components, modelled by a thermodynamic simulator (Proceedings of the Conference on High Temperature Reactors, Beijing, China, 22-24 September 2004, International Atomic Agency, Vienna (Austria), HTR-2004; 1-11). The minimization of exergy destruction is then identified as the optimization criterion used in an optimization framework based on a genetic algorithm, in which the model is embedded. Finally, the approach is applied to electrical production by a Brayton-Rankine combined cycle connected to a nuclear reactor. Some typical results are presented. The perspectives of this work including the cogeneration of hydrogen and electricity are highlighted. (authors)

  11. Exergy analysis for Generation IV nuclear plant optimization

    Energy Technology Data Exchange (ETDEWEB)

    Gomez, A.; Azzaro-Pantel, C.; Domenech, S.; Pibouleau, L. [Univ Toulouse, Lab Genie Chim, CNRS, UMR 5503, F-31700 Toulouse 1 (France); Latge, Ch. [CEA Cadarache DEN DTN DIR, St Paul Les Durance, (France); Haubensack, D.; Dumaz, P. [CEA Cadarache DEN DER SESI LCSI, St Paul Les Durance (France)

    2010-07-01

    This paper deals with the application of the exergy concept to an energy production system involving a very high temperature reactor coupled with an innovative electricity-generating cycle. The objective is to propose a general approach to quantify exergy destruction of the involved process components, modelled by a thermodynamic simulator (Proceedings of the Conference on High Temperature Reactors, Beijing, China, 22-24 September 2004, International Atomic Agency, Vienna (Austria), HTR-2004; 1-11). The minimization of exergy destruction is then identified as the optimization criterion used in an optimization framework based on a genetic algorithm, in which the model is embedded. Finally, the approach is applied to electrical production by a Brayton-Rankine combined cycle connected to a nuclear reactor. Some typical results are presented. The perspectives of this work including the cogeneration of hydrogen and electricity are highlighted. (authors)

  12. Next Generation Nuclear Plant Materials Research and Development Program Plan, Revision 4

    Energy Technology Data Exchange (ETDEWEB)

    G.O. Hayner; R.L. Bratton; R.E. Mizia; W.E. Windes; W.R. Corwin; T.D. Burchell; C.E. Duty; Y. Katoh; J.W. Klett; T.E. McGreevy; R.K. Nanstad; W. Ren; P.L. Rittenhouse; L.L. Snead; R.W. Swindeman; D.F. Wlson

    2007-09-01

    DOE has selected the High Temperature Gas-cooled Reactor (HTGR) design for the Next Generation Nuclear Plant (NGNP) Project. The NGNP will demonstrate the use of nuclear power for electricity and hydrogen production. It will have an outlet gas temperature in the range of 950°C and a plant design service life of 60 years. The reactor design will be a graphite moderated, helium-cooled, prismatic or pebble-bed reactor and use low-enriched uranium, TRISO-coated fuel. The plant size, reactor thermal power, and core configuration will ensure passive decay heat removal without fuel damage or radioactive material releases during accidents. The NGNP Materials Research and Development (R&D) Program is responsible for performing R&D on likely NGNP materials in support of the NGNP design, licensing, and construction activities. Some of the general and administrative aspects of the R&D Plan include: • Expand American Society of Mechanical Engineers (ASME) Codes and American Society for Testing and Materials (ASTM) Standards in support of the NGNP Materials R&D Program. • Define and develop inspection needs and the procedures for those inspections. • Support selected university materials related R&D activities that would be of direct benefit to the NGNP Project. • Support international materials related collaboration activities through the DOE sponsored Generation IV International Forum (GIF) Materials and Components (M&C) Project Management Board (PMB). • Support document review activities through the Materials Review Committee (MRC) or other suitable forum.

  13. HIGH EFFICIENCY GENERATION OF HYDROGEN FUELS USING NUCLEAR POWER FINAL RECHNICAL REPORT FOR THE PERIOD AUGUST 1, 1999 THROUGH SEPTEMBER 30, 2002 REV. 1

    Energy Technology Data Exchange (ETDEWEB)

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

    2003-12-01

    OAK-B135 Combustion of fossil fuels, used to power transportation, generate electricity, heat homes and fuel industry provides 86% of the world's energy [1-1,1-2]. 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 [1-3,1-4]. 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 fossil fuels has trace contaminants (primarily

  14. Pressurized fluidized bed combustion combined cycle power plant with coal gasification: Second generation pilot plant

    International Nuclear Information System (INIS)

    Farina, G.L.; Bressan, L.

    1991-01-01

    This paper presents the technical and economical background of a research and development program of a novel power generation scheme, which is based on coal gasification, pressurized fluid bed combustion and combined cycles. The participants in this program are: Foster Wheeler (project leader), Westinghouse, IGT and the USA Dept. of Energy. The paper describes the characteristics of the plant, the research program in course of implementation, the components of the pilot plant and the first results obtained

  15. Biological consilience of hydrogen sulfide and nitric oxide in plants: Gases of primordial earth linking plant, microbial and animal physiologies.

    Science.gov (United States)

    Yamasaki, Hideo; Cohen, Michael F

    2016-05-01

    Hydrogen sulfide (H2S) is produced in the mammalian body through the enzymatic activities of cystathionine β-synthase (CBS), cystathionine γ-lyase (CSE) and 3-mercaptopyruvate sulfurtransferase (3MST). A growing number of studies have revealed that biogenic H2S produced in tissues is involved in a variety of physiological responses in mammals including vasorelaxation and neurotransmission. It is now evident that mammals utilize H2S to regulate multiple signaling systems, echoing the research history of the gaseous signaling molecules nitric oxide (NO) and carbon monoxide (CO) that had previously only been recognized for their cytotoxicity. In the human diet, meats (mammals, birds and fishes) and vegetables (plants) containing cysteine and other sulfur compounds are the major dietary sources for endogenous production of H2S. Plants are primary producers in ecosystems on the earth and they synthesize organic sulfur compounds through the activity of sulfur assimilation. Although plant H2S-producing activities have been known for a long time, our knowledge of H2S biology in plant systems has not been updated to the extent of mammalian studies. Here we review recent progress on H2S studies, highlighting plants and bacteria. Scoping the future integration of H2S, NO and O2 biology, we discuss a possible linkage between physiology, ecology and evolutional biology of gas metabolisms that may reflect the historical changes of the Earth's atmospheric composition. Copyright © 2016 Elsevier Inc. All rights reserved.

  16. Hydrogen Fuel as Ecological Contribution to Operation of the Existing Coal-Fired Thermal Power Plants

    International Nuclear Information System (INIS)

    Cosic, D.

    2009-01-01

    The analysis is carried out of the application of a new hydrogen based alternative fuel as ecological contribution of the coal thermal power plants operation. Given the fact that coal thermal power plants are seen as the largest producers, not only of CO 2 , but of all others harmful gases, the idea is initiated to use the new alternative fuel as an additive to the coal which would result in much better performance of the coal power plants from an ecological point of view. It is possible to use such a fuel in relation of 10-30% of former coal use. The positive influence of such an application is much bigger than relative used quantity. This lecture has a goal to incite potential investors to create conditions for industrial testing of the new fuel. It will be very interesting to animate investors for large-scale production of the new fuel, too.(author).

  17. Leak detection in steam generators with hydrogen monitors using diffusion membranes

    Energy Technology Data Exchange (ETDEWEB)

    Hissink, M

    1975-07-01

    Large water leaks in steam-generators give rise to violent chemical reactions which can only be controlled by a pressure relief system. Smaller leaks do not pose direct safety hazards but wastage of pipes surrounding the leak should be prevented. Leak detection is best carried out by monitors recording the hydrogen in sodium content. For large leaks the specification of these monitors causes no problems, contrary to those for the timely detection of small leaks. Essential parameters are sensitivity and speed of response, specificity is less important. But apart from the instrument specification, a number of factors, related to the construction and operation of the steam-generator, determine the performance of the leak detection system. A discussion of these factors is given, with a view to the design of the SNR-300. Although tile results of many theoretical studies and experimental work are available, there seems to be room for further investigations on the growths of minor leaks. Also lacking a sufficient experience concerning the level and fluctuations of the hydrogen background in the sodium. A description is given of the hydrogen monitor developed at TNO, which is based on a combination of a nickel membrane and an ion getter pump. The parameters of this instrument have been evaluated in a test rig. Operational experience with the monitor is available from the 50 MW Test Facility at Hengelo. Especially for further studies the need for a calibrated instrument has become apparent. Test are going on with a modified design of a monitor meeting this requirement. (author)

  18. Thermal generation and mobility of charge carriers in collective proton transport in hydrogen-bonded chains

    International Nuclear Information System (INIS)

    Peyrard, M.; Boesch, R.; Kourakis, I.

    1991-01-01

    The transport of protons in hydrogen-bonded systems is a long standing problem which has not yet obtained a satisfactorily theoretical description. Although this problem was examined first for ice, it is relevant in many systems and in particular in biology for the transport along proteins or for proton conductance across membranes, an essential process in cell life. The broad relevance makes the study of proton conduction very appealing. Since the original work of Bernal and Fowler on ice, the idea that the transport occurs through chains of hydrogen bonds has been well accepted. Such ''proton wires'' were invoked by Nagle and Morowitz for proton transport across membranes proteins and more recently across lipid bilayers. In this report, we assume the existence of such an hydrogen-bonded chain and discuss its consequences on the dynamics of the charge carriers. We show that this assumption leads naturally to the idea of soliton transport and we put a special emphasis on the role of the coupling between the protons and heavy ions motions. The model is presented. We show how the coupling affects strongly the dynamics of the charge carriers and we discuss the role it plays in the thermal generation of carriers. The work presented has been performed in 1986 and 87 with St. Pnevmatikos and N. Flyzanis and was then completed in collaboration with D. Hochstrasser and H. Buettner. Therefore the results presented in this part are not new but we think that they are appropriate in the context of this multidisciplinary workshop because they provide a rather complete example of the soliton picture for proton conduction. This paper discusses the thermal generation of the charge carriers when the coupling between the protons and heavy ions dynamics is taken into account. The results presented in this part are very recent and will deserve further analysis but they already show that the coupling can assist for the formation of the charge carriers

  19. Power generation enhancement in a salinity-gradient solar pond power plant using thermoelectric generator

    International Nuclear Information System (INIS)

    Ziapour, Behrooz M.; Saadat, Mohammad; Palideh, Vahid; Afzal, Sadegh

    2017-01-01

    Highlights: • Thermoelectric generator was used and simulated within a salinity-gradient solar pond power plant. • Results showed that the thermoelectric generator can be able to enhance the power plant efficiency. • Results showed that the presented models can be able to produce generation even in the cold months. • The optimum size of area of solar pond based on its effect on efficiency is 50,000 m 2 . - Abstract: Salinity-gradient solar pond (SGSP) has been a reliable supply of heat source for power generation when it has been integrated with low temperature thermodynamics cycles like organic Rankine cycle (ORC). Also, thermoelectric generator (TEG) plays a critical role in the production of electricity from renewable energy sources. This paper investigates the potential of thermoelectric generator as a power generation system using heat from SGSP. In this work, thermoelectric generator was used instead of condenser of ORC with the purpose of improving the performance of system. Two new models of SGSP have been presented as: (1) SGSP using TEG in condenser of ORC without heat exchanger and (2) SGSP using TEG in condenser of ORC with heat exchanger. These proposed systems was evaluated through computer simulations. The ambient conditions were collected from beach of Urmia lake in IRAN. Simulation results indicated that, for identical conditions, the model 1 has higher performance than other model 2. For models 1 and 2 in T LCZ = 90 °C, the overall thermal efficiency of the solar pond power plant, were obtained 0.21% and 0.2% more than ORC without TEG, respectively.

  20. Analysis of hydrogen generation according to the specific concrete composition during severe accident

    International Nuclear Information System (INIS)

    Seo, M. R.; Kim, M. K.

    2001-01-01

    The chemical composition of reactor cavity floor concrete affects the kind and amout of gases generated by MCCI and ablation of concrete. And if affects the physical and chemical characteristics of molten pool formed in the cavity. So, the specific concrete compostion is inputted in the MAAP Code used in the Level 2 PSA. and since Ulchin Unit 3 and 4 PSA, the analysis of concrete composition has been performed by the concrete mold prepared for this usage at the installation of cavity floor concrete. But, the composition of domestic concrete for construction of NPP is nearly the same as that of the standard basaltic concrete, and the effect of minor variation in composition is expected to be negligible. This report analyze the effect of the concrete composition to the generation of hydrogen due to MCCI, and discuss the necessity of analysis about the specific concrete composition for Level 2 PSA

  1. Synthesis and Characterization of K-Ta Mixed Oxides for Hydrogen Generation in Photocatalysis

    Directory of Open Access Journals (Sweden)

    Beata Zielińska

    2012-01-01

    Full Text Available K-Ta mixed oxides photocatalysts have been prepared by impregnation followed by calcination. The influence of the reaction temperature (450°C–900°C on the phase formation, crystal morphology, and photocatalytic activity in hydrogen generation of the produced materials was investigated. The detailed analysis has revealed that all products exhibit high crystallinity and irregular structure. Moreover, two different crystal structures of potassium tantalates such as KTaO3 and K2Ta4O11 were obtained. It was also found that the sample composed of KTaO3 and traces of unreacted Ta2O5 (annealed at 600°C exhibits the highest activity in the reaction of photocatalytic hydrogen generation. The crystallographic phases, optical and vibronic properties were examined by X-ray diffraction (XRD and diffuse reflectance (DR UV-vis and resonance Raman spectroscopic methods, respectively. Morphology and chemical composition of the produced samples were studied using a high-resolution transmission electron microscope (HR-TEM and an energy dispersive X-ray spectrometer (EDX as its mode.

  2. Hydrogen generation due to water splitting on Si - terminated 4H-Sic(0001) surfaces

    Science.gov (United States)

    Li, Qingfang; Li, Qiqi; Yang, Cuihong; Rao, Weifeng

    2018-02-01

    The chemical reactions of hydrogen gas generation via water splitting on Si-terminated 4H-SiC surfaces with or without C/Si vacancies were studied by using first-principles. We studied the reaction mechanisms of hydrogen generation on the 4H-SiC(0001) surface. Our calculations demonstrate that there are major rearrangements in surface when H2O approaches the SiC(0001) surface. The first H splitting from water can occur with ground-state electronic structures. The second H splitting involves an energy barrier of 0.65 eV. However, the energy barrier for two H atoms desorbing from the Si-face and forming H2 gas is 3.04 eV. In addition, it is found that C and Si vacancies can form easier in SiC(0001)surfaces than in SiC bulk and nanoribbons. The C/Si vacancies introduced can enhance photocatalytic activities. It is easier to split OH on SiC(0001) surface with vacancies compared to the case of clean SiC surface. H2 can form on the 4H-SiC(0001) surface with C and Si vacancies if the energy barriers of 1.02 and 2.28 eV are surmounted, respectively. Therefore, SiC(0001) surface with C vacancy has potential applications in photocatalytic water-splitting.

  3. Hydrothermal Synthesis of Co-Ru Alloy Particle Catalysts for Hydrogen Generation from Sodium Borohydride

    Directory of Open Access Journals (Sweden)

    Marija Kurtinaitienė

    2013-01-01

    Full Text Available We report the synthesis of μm and sub-μm-sized Co, Ru, and Co-Ru alloy species by hydrothermal approach in the aqueous alkaline solutions (pH ≥ 13 containing CoCl2 and/or RuCl3, sodium citrate, and hydrazine hydrate and a study of their catalytic properties for hydrogen generation by hydrolysis of sodium borohydride solution. This way provides a simple platform for fabrication of the ball-shaped Co-Ru alloy catalysts containing up to 12 wt% Ru. Note that bimetallic Co-Ru alloy bowls containing even 7 at.% Ru have demonstrated catalytic properties that are comparable with the ones of pure Ru particles fabricated by the same method. This result is of great importance in view of the preparation of cost-efficient catalysts for hydrogen generation from borohydrides. The morphology and composition of fabricated catalyst particles have been characterized using scanning electron microscopy, energy dispersive X-ray diffraction, and inductively coupled plasma optical emission spectrometry.

  4. Co3O4 nanowires as efficient catalyst precursor for hydrogen generation from sodium borohydride hydrolysis

    Science.gov (United States)

    Wei, Lei; Cao, Xurong; Ma, Maixia; Lu, Yanhong; Wang, Dongsheng; Zhang, Suling; Wang, Qian

    Hydrogen generation from the catalytic hydrolysis of sodium borohydride has many advantages, and therefore, significant research has been undertaken on the development of highly efficient catalysts for this purpose. In our present work, Co3O4 nanowires were successfully synthesized as catalyst precursor by employing SBA-15 as a hard template. For material characterization, high-resolution transmission electron microscopy (HRTEM), powder X-ray diffraction (XRD), fourier-transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), inductively coupled plasma-atomic emission spectroscopy (ICP-AES) and N2 adsorption isotherms were employed, respectively. To measure the catalyst activity, typical water-displacement method was carried out. Using a reaction solution comprising 10wt.% NaBH4 and 2wt.% NaOH, the hydrogen generation rate (HGR) was observed to be as high as 7.74L min-1 g-1 at 25∘C in the presence of Co3O4 nanowires, which is significantly higher than that of CoB nanoparticles and commercial Co3O4 powder. Apparent activation energy was calculated to be 50.9kJ mol-1. After recycling the Co3O4 nanowires six times, HGR was decreased to be 72.6% of the initial level.

  5. Dynamis - a step towards the first HYPOGEN plant, producing hydrogen and electricity with near zero emissions

    Energy Technology Data Exchange (ETDEWEB)

    Petter E. Roekke; Nils A. Roekke; Jens Hetland; Peter Radgen; Clemens Cremer; Tore A. Torp [SINTEF Energy Research, Trondheim (Norway)

    2006-07-01

    This paper refers to the Dynamis project, which represents the second phase of the route towards the HYPOGEN initiative of the European Commission, building on results and experience from the HYPOGEN pre-feasibility study. The paper will describe the European policy of enabling hydrogen as a more significant energy carrier in Europe, through processing of fossil fuels to hydrogen and electricity with CO{sub 2} capture and storage. The paper will address the two first phases of the endeavor; the HYPOGEN pre-feasibility study was completed in 2005, and Dynamis was started early 2006. Both relate to the technical, economic and societal pre-requisites of each dimension to early decisions in order for a HYPOGEN plant to go on stream by 2012. 9 refs., 2 figs.

  6. CFD analyses of steam and hydrogen distribution in a nuclear power plant

    International Nuclear Information System (INIS)

    Siccama, N.B.; Houkema, M.; Komen, E.M.J.

    2003-01-01

    A detailed three-dimensional Computational Fluid Dynamics (CFD) model of the containment of the nuclear power plant has been prepared in order to assess possible multidimensional phenomena. In a first code-to-code comparison step, the CFD model has been used to compute a reference accident scenario which has been analysed earlier with the lumped parameter code SPECTRA. The CFD results compare qualitatively well with the SPECTRA results. Subsequently, the actual steam jet from the primary system has been modelled in the CFD code in order to determine the hydrogen distribution for this realistically modelled source term. Based on the computed hydrogen distributions, it has been determined when use of lumped parameter codes is allowed and when use of CFD codes is required. (author)

  7. Competitive positioning of power generation plants in a deregulated market

    International Nuclear Information System (INIS)

    Stephens, J.

    1998-01-01

    As industrialized countries deregulate their electric power industries, there is a fundamental shift from guaranteed cost recovery to open market competition on a deregulated grid. Utilities generally competitively bid into a power exchange where the lowest cost power providers are dispatched first. Therefore, the competitiveness of utilities determines their profitability. This commercial structure compels power generators to seek out ways of improving their equipment and plant performance. The inevitability of this trend is demonstrated by a look at the installed base in the US where the move toward deregulation is gaining momentum. More than half of the generating plants in the US are over 20 years old. The average thermal efficiency nation-wide is 33%. In contrast, contemporary coal-and gas-fired plants can operate at efficiency levels up to 45 percent and 55 to 60%, respectfully. With new facilities coming on-line, existing plants will need to make improvements to be dispatched. When deregulation fully envelopes the US market, utilities will not all fit into one pattern; their strategies and actions will depend on a multiple set of factors. Their success will be based on their ability to change landscapes from guaranteed cost recovery to competitive bidding. This paper discussers technical and commercial options available to power producers to improve their competitive positions in a deregulated market as well as software for determining the competitiveness of specific power plants and the location-based market prices of electricity. Examples of the application of alternatives will be cited along with expected payback and impact on cents per kilowatt-hour production costs

  8. 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.

  9. Steam generator for use in nuclear power plants

    International Nuclear Information System (INIS)

    Cella, A.

    1980-01-01

    An improved steam generator is described for use in a nuclear power plant of the pressurized water type in which a turbine generator is driven by the steam output of the steam generator to provide electrical power therefrom. The improvement comprises providing a vertically movable grid structure vertically extending within the interior of the lower housing portion of the steam generator through which individual tubes comprising a vertically extending tube bundle extend. The tube bundle has a tube sheet at one end thereof supporting the tube bundle for the tubes extending through the tube sheet in flow through communication with a heat exchange fluid inlet. The grid structure defines grid apertures therein through which the individual tubes extend with each of the grid apertures being in surrounding relationship with a portion of an associated one of the tubes. The grid structure is movable for a predetermined vertical extent, such as by hydraulic means, such as a piston, along the tubes for vertically displacing the means defining the grid apertures by a sufficient amount for removing the previously surrounded portion of each of the tubes from the associated grid apertures whereby an enhanced reading of the condition of the tubes at the previously surrounded portion is enabled. The steam generator may comprise vertically assemblable modules which are removably mounted together in sealing relationship, with the modules comprising a base module, a tube bundle module removably mountable on the base module in sealing relationship therewith and an uppermost drier module removably mountable on the tube bundle module in sealing relationship therewith whereby ready access to removal of the tube bundle module in situ from the nuclear power plant steam generator is facilitated

  10. Modelling of hydrogen sulfide dispersion from the geothermal power plants of Tuscany (Italy)

    Science.gov (United States)

    Renato, Somma; Domenico, Granieri; Claudia, Troise; Carlo, Terranova; Natale Giuseppe, De; Maria, Pedone

    2017-04-01

    The hydrogen sulfide (H2S) is one of the main gaseous substances contained in deep fluids exploited by geo-thermoelectric plant. Therefore, it is a "waste" pollutant product by plants for energy production. Hydrogen sulfide is perceived by humans at very low concentrations in the air ( 0,008 ppm, World Health Organization, hereafter WHO, 2003) but it becomes odorless in higher concentrations (> 100 ppm, WHO, 2003) and, for values close to the ones lethal (> 500 ppm), produces an almost pleasant smell. The typical concentration in urban areas is <0.001ppm (<1ppb); in volcanic plumes it reaches values between 0.1 and 0.5 ppm. WHO defines the concentration and relative effects on human health. We applied the Eulerian code DISGAS (DISpersion of GAS) to investigate the dispersion of the hydrogen sulfide (H2S) from 32 geothermal power plants (out of 35 active) belonging to the geothermal districts of Larderello, Travale-Radicondoli and Monte Amiata, in Tuscany (Italy). DISGAS code has simulated scenarios consistent with the prevailing wind conditions, estimating reasonable H2S concentrations for each area, and for each active power plant. The results suggest that H2S plumes emitted from geothermal power plants are mainly concentrated around the stacks of emission (H2S concentration up to 1100 ug/m3) and rapidly dilute along the dominant local wind direction. Although estimated values of air H2S concentrations are orders of magnitude higher than in unpolluted areas, they do not indicate an immediate health risk for nearby communities, under the more frequent local atmospheric conditions. Starting from the estimated values, validated by measurements in the field, we make some considerations about the environmental impact of the H2S emission in all the geothermal areas of the Tuscany region. Furthermore, this study indicates the potential of DISGAS as a tool for an improved understanding of the atmospheric and environmental impacts of the H2S continuous degassing from

  11. Initial Screening of Thermochemical Water-Splitting Cycles for High Efficiency Generation of Hydrogen Fuels Using Nuclear Power

    International Nuclear Information System (INIS)

    Brown, L.C.; Funk, J.F.; Showalter, S.K.

    1999-01-01

    OAK B188 Initial Screening of Thermochemical Water-Splitting Cycles for High Efficiency Generation of Hydrogen Fuels Using Nuclear Power There is currently no large scale, cost-effective, environmentally attractive hydrogen production process, nor is such a process available for commercialization. Hydrogen is a promising energy carrier, which potentially could replace the fossil fuels used in the transportation sector of our economy. Fossil fuels are polluting and carbon dioxide emissions from their combustion are thought to be responsible for global warming. The purpose of this work is to determine the potential for efficient, cost-effective, large-scale production of hydrogen utilizing high temperature heat from an advanced nuclear power station. Almost 800 literature references were located which pertain to thermochemical production of hydrogen from water and over 100 thermochemical watersplitting cycles were examined. Using defined criteria and quantifiable metrics, 25 cycles have been selected for more detailed study

  12. Development of a Novel Efficient Solid-Oxide Hybrid for Co-generation of Hydrogen and Electricity Using Nearby Resources for Local Application

    Energy Technology Data Exchange (ETDEWEB)

    Tao, Greg, G.; Virkar, Anil, V.; Bandopadhyay, Sukumar; Thangamani, Nithyanantham; Anderson, Harlan, U.; Brow, Richard, K.

    2009-06-30

    Developing safe, reliable, cost-effective, and efficient hydrogen-electricity co-generation systems is an important step in the quest for national energy security and minimized reliance on foreign oil. This project aimed to, through materials research, develop a cost-effective advanced technology cogenerating hydrogen and electricity directly from distributed natural gas and/or coal-derived fuels. This advanced technology was built upon a novel hybrid module composed of solid-oxide fuel-assisted electrolysis cells (SOFECs) and solid-oxide fuel cells (SOFCs), both of which were in planar, anode-supported designs. A SOFEC is an electrochemical device, in which an oxidizable fuel and steam are fed to the anode and cathode, respectively. Steam on the cathode is split into oxygen ions that are transported through an oxygen ion-conducting electrolyte (i.e. YSZ) to oxidize the anode fuel. The dissociated hydrogen and residual steam are exhausted from the SOFEC cathode and then separated by condensation of the steam to produce pure hydrogen. The rationale was that in such an approach fuel provides a chemical potential replacing the external power conventionally used to drive electrolysis cells (i.e. solid oxide electrolysis cells). A SOFC is similar to the SOFEC by replacing cathode steam with air for power generation. To fulfill the cogeneration objective, a hybrid module comprising reversible SOFEC stacks and SOFC stacks was designed that planar SOFECs and SOFCs were manifolded in such a way that the anodes of both the SOFCs and the SOFECs were fed the same fuel, (i.e. natural gas or coal-derived fuel). Hydrogen was produced by SOFECs and electricity was generated by SOFCs within the same hybrid system. A stand-alone 5 kW system comprising three SOFEC-SOFC hybrid modules and three dedicated SOFC stacks, balance-of-plant components (including a tailgas-fired steam generator and tailgas-fired process heaters), and electronic controls was designed, though an overall

  13. Covariance of oxygen and hydrogen isotopic composition in plant water: Species effects

    Energy Technology Data Exchange (ETDEWEB)

    Cooper, L.W.; DeNiro, M.J. (Univ. of California, Los Angeles (United States))

    1989-12-01

    Leaf water becomes enriched in the heavy isotopes of oxygen and hydrogen during evapotranspiration. The magnitude of the enrichment has been shown to be influenced by temperature and humidity, but the effects of species-specific factors on leaf water enrichment of D and {sup 18}O have not been studied for different plants growing together. To learn whether leaf water enrichment patterns and processes for D and {sup 18}O are different for individual species growing under the same environmental conditions the authors tested the proposal that leaf waters in plants with crassulacean acid metabolism (CAM) show high sloped (m in the leaf water equation {delta}D = m {delta}{sup 18}O + b) than in C{sub 3} plants. They determined the relationships between the stable hydrogen ({delta}D) and oxygen ({delta}{sup 18}O) isotope ratios of leaf waters collected during the diurnal cycle of evapotranspiration for Yucca schidigera, Ephedra aspera, Agave deserti, Prunus ilicifolia, Yucca whipplei, Heteromeles arbutifolia, Dyckia fosteriana, Simmondsia chinensis, and Encelia farinosa growing at two sites in southern California. The findings indicate that m in the aforementioned equation is related to the overall residence time for water in the leaf and proportions of water subjected to repeated evapotranspiration enrichments of heavy isotopes.

  14. Dibenzothiophene hydrodesulfurization over Ru promoted alumina based catalysts using in situ generated hydrogen

    International Nuclear Information System (INIS)

    Muhammad, Yaseen; Lu Yingzhou; Shen Chong; Li Chunxi

    2011-01-01

    Catalytic hydrodesulfurization (HDS) of dibenzothiophene (DBT) was carried out in a temperature range of 320-400 o C using in situ generated hydrogen coupled with the effect of selected organic additives for the first time. Four kinds of alumina based catalysts i.e. Co-Mo/Al 2 O 3 , Ni-Mo/Al 2 O 3 , Ru-Co-Mo/Al 2 O 3 and Ru-Ni-Mo/Al 2 O 3 were used for the desulfurization process, which were prepared following incipient impregnation method with fixed metal loadings (wt.%) of Co, Ni, Mo and Ru. The surface area, average pore diameter and pore volume distribution of the fresh and used catalysts were measured by N 2 adsorption using BET method. Catalytic activity was investigated in a batch autoclave reactor in the complete absence of external hydrogen gas. Addition and mutual reaction of specific quantities of water and ethanol provided the necessary in situ hydrogen for the desulfurization reaction. Organic additives like diethylene glycol (DEG), phenol, naphthalene, anthracene, o-xylene, tetralin, decalin and pyridine did impinge the HDS activity of the catalysts in different ways. Liquid samples from reaction products were quantitatively analyzed by HPLC technique while qualitative analyses were made using GC-MS. Both of these techniques showed that Ni-based catalysts were more active than Co-based ones at all conditions. Moreover, incorporation of Ru to both Co and Ni-based catalysts greatly promoted desulfurization activity of these catalysts. DBT conversion of up to 84% was achieved with Ru-Ni-Mo/Al 2 O 3 catalyst at 380 o C temperature for 11 h. Catalyst systems followed the HDS activity order as: Ru-Ni-Mo/Al 2 O 3 > Ni-Mo/Al 2 O 3 > Ru-Co-Mo/Al 2 O 3 > Co-Mo/Al 2 O 3 at all conditions. Cost effectiveness, mild operating conditions and reasonably high catalytic activity using in situ generated hydrogen mechanism proved our process to be useful for HDS of DBT.

  15. Dibenzothiophene hydrodesulfurization over Ru promoted alumina based catalysts using in situ generated hydrogen

    Energy Technology Data Exchange (ETDEWEB)

    Muhammad, Yaseen; Shen, Chong; Li, Chunxi [State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing 100029 (China); College of Chemical Engineering, Beijing University of Chemical Technology, Beijing 100029 (China); Lu, Yingzhou [College of Chemical Engineering, Beijing University of Chemical Technology, Beijing 100029 (China)

    2011-02-15

    Catalytic hydrodesulfurization (HDS) of dibenzothiophene (DBT) was carried out in a temperature range of 320-400 C using in situ generated hydrogen coupled with the effect of selected organic additives for the first time. Four kinds of alumina based catalysts i.e. Co-Mo/Al{sub 2}O{sub 3}, Ni-Mo/Al{sub 2}O{sub 3}, Ru-Co-Mo/Al{sub 2}O{sub 3} and Ru-Ni-Mo/Al{sub 2}O{sub 3} were used for the desulfurization process, which were prepared following incipient impregnation method with fixed metal loadings (wt.%) of Co, Ni, Mo and Ru. The surface area, average pore diameter and pore volume distribution of the fresh and used catalysts were measured by N{sub 2} adsorption using BET method. Catalytic activity was investigated in a batch autoclave reactor in the complete absence of external hydrogen gas. Addition and mutual reaction of specific quantities of water and ethanol provided the necessary in situ hydrogen for the desulfurization reaction. Organic additives like diethylene glycol (DEG), phenol, naphthalene, anthracene, o-xylene, tetralin, decalin and pyridine did impinge the HDS activity of the catalysts in different ways. Liquid samples from reaction products were quantitatively analyzed by HPLC technique while qualitative analyses were made using GC-MS. Both of these techniques showed that Ni-based catalysts were more active than Co-based ones at all conditions. Moreover, incorporation of Ru to both Co and Ni-based catalysts greatly promoted desulfurization activity of these catalysts. DBT conversion of up to 84% was achieved with Ru-Ni-Mo/Al{sub 2}O{sub 3} catalyst at 380 C temperature for 11 h. Catalyst systems followed the HDS activity order as: Ru-Ni-Mo/Al{sub 2}O{sub 3}> Ni-Mo/Al{sub 2}O{sub 3}> Ru-Co-Mo/Al{sub 2}O{sub 3}> Co-Mo/Al{sub 2}O{sub 3} at all conditions. Cost effectiveness, mild operating conditions and reasonably high catalytic activity using in situ generated hydrogen mechanism proved our process to be useful for HDS of DBT. (author)

  16. Air-stable hydrogen generation materials and enhanced hydrolysis performance of MgH2-LiNH2 composites

    Science.gov (United States)

    Ma, Miaolian; Ouyang, Liuzhang; Liu, Jiangwen; Wang, Hui; Shao, Huaiyu; Zhu, Min

    2017-08-01

    Hydrolysis of materials in water can be a promising solution of onsite hydrogen generation for realization of hydrogen economy. In this work, it was the first time that the MgH2-LiNH2 composites were explored as air-stable hydrolysis system for hydrogen generation. The MgH2-LiNH2 composites with different composition ratios were synthesized by ball milling with various durations and the hydrogen generation performances of the composite samples were investigated and compared. X-ray diffraction, X-ray photoelectron spectroscopy and scanning electron microscopy techniques were adopted to elucidate the performance improvement mechanisms. The hydrolysis properties of MgH2 were found to be significantly enhanced by the introduction of LiNH2. The 4MgH2-LiNH2 composite ball milled for 5 h can generate 887.2 mL g-1 hydrogen in 1 min and 1016 mL g-1 in 50 min, one of the best results so far for Mg based hydrolysis materials. The LiOH·H2O and NH4OH phases of hydrolysis products from LiNH2 may prevent formation of Mg(OH)2 passivation layer on the surface and supply enough channels for hydrolysis of MgH2. The MgH2-LiNH2 composites appeared to be very stable in air and no obvious negative effect on kinetics and hydrogen generation yield was observed. These good performances demonstrate that the studied MgH2-LiNH2 composites can be a promising and practicable hydrogen generation system.

  17. Covariance of oxygen and hydrogen isotopic compositions in plant water: species effects

    International Nuclear Information System (INIS)

    Cooper, L.W.; DeNiro, M.J.

    1989-01-01

    Leaf water becomes enriched in the heavy isotopes of oxygen and hydrogen during evapotranspiration. The magnitude of the enrichment has been shown to be influenced by temperature and humidity, but the effects of species—specific factors on leaf water enrichment of D and 18 O have not been studied for different plants growing together. Accordingly, to learn whether leaf water enrichment patterns and processes for D and 18 O are different for individual species growing under the same environmental conditions we tested the proposal that leaf waters in plants with crassulacean acid metabolism (CAM) show higher slopes (m in the leaf water equation °D = m ° 18 O + b) than in C 3 plants. We determined the relationships between the stable hydrogen (°D) and oxygen (° 18 O) isotope ratios of leaf waters collected during the diurnal cycle of evapotranspiration for Yucca schidigera, Ephedra aspera, Agave deserti, Prunus ilicifolia, Yucca whipplei, Heteromeles arbutifolia, Dyckia fosteriana, Simmondsia chinensis, and Encelia farinosa growing at two sites in southern California. Slopes (m in the above leaf water equation) ranged from 1.50 to 3.21, compared to °8 for meteoric water, but differences in slope could not be attributed to carboxylation pathway (CAM vs. C 3 ) nor climate (coastal California vs. Sonoran Desert). Higher slopes were correlated with greater overall ranges of leaf water enrichment of D and 18 O. Water in plants with higher slopes also differed most from unaltered meteoric water. Leaf water isotope ratios in plants with lower slopes were better correlated with temperature and humidity. The findings indicate that m in the aforementioned equation is related to the overall residence time for water in the leaf and proportions of water subjected to repeated evapotranspiration enrichments of heavy isotopes

  18. Photoelectrochemical study of nanostructured ZnO thin films for hydrogen generation from water splitting

    Energy Technology Data Exchange (ETDEWEB)

    Wolcott, Abraham; Zhang, Jin Z. [Department of Chemistry and Biochemistry, University of California, Santa Cruz 1156 High St. Santa Cruz, CA 95064 (United States); Smith, Wilson A.; Zhao, Yiping [Department of Physics and Astronomy, University of Georgia, Athens, GA 30602 (United States); Kuykendall, Tevye R. [Department of Chemistry, University of California, Berkeley Berkeley, CA 94720 (United States)

    2009-06-23

    Photoelectrochemical cells based on traditional and nanostructured ZnO thin films are investigated for hydrogen generation from water splitting. The ZnO thin films are fabricated using three different deposition geometries: normal pulsed laser deposition, pulsed laser oblique-angle deposition, and electron-beam glancing-angle deposition. The nanostructured films are characterized by scanning electron microscopy, X-ray diffraction, UV-vis spectroscopy and photoelectrochemical techniques. Normal pulsed laser deposition produces dense thin films with ca. 200 nm grain sizes, while oblique-angle deposition produces nanoplatelets with a fishscale morphology and individual features measuring ca. 900 by 450 nm on average. In contrast, glancing-angle deposition generates a highly porous, interconnected network of spherical nanoparticles of 15-40 nm diameter. Mott-Schottky plots show the flat band potential of pulsed laser deposition, oblique-angle deposition, and glancing-angle deposition samples to be -0.29, -0.28 and +0.20 V, respectively. Generation of photocurrent is observed at anodic potentials and no limiting photocurrents were observed with applied potentials up to 1.3 V for all photoelectrochemical cells. The effective photon-to-hydrogen efficiency is found to be 0.1%, 0.2% and 0.6% for pulsed laser deposition, oblique-angle deposition and glancing-angle deposition samples, respectively. The photoelectrochemical properties of the three types of films are understood to be a function of porosity, crystal defect concentration, charge transport properties and space charge layer characteristics. (Abstract Copyright [2009], Wiley Periodicals, Inc.)

  19. Accident for natural gas well with hydrogen sulfide in relation to nuclear power plant siting

    International Nuclear Information System (INIS)

    Tan Chengjun; Shangguang Zhihong; Sha Xiangdong

    2010-01-01

    In order to make assessment to the potential impact from accident of natural gas wells with hydrogen sulfide on the habitability of main control room of nuclear power plant (NPP), several assumptions such as source terms of maximum credible accident, conservative atmospheric conditions and release characteristics were proposed in the paper, and the impact on the habitability of main control room was evaluated using toxicity thresholds recommended by foreign authority. Case results indicate that the method can provide the reference for the preliminary assessment to external human-induced events during the siting phrase of NPP. (authors)

  20. Low doses of ionizing radiation and hydrogen peroxide stimulate plant growth

    International Nuclear Information System (INIS)

    Korystov, Y.; Narimanov, A.

    1997-01-01

    The present study shows that low-dose oxidative stress induced by ionizing radiation (10-20 cGy) and hydrogen peroxide (1-100 pmol per litre) stimulates germination of seeds and growth of sprouts and roots. The growth of seedlings can be stimulated by treatment of seeds as well as seedlings but in the latter case it needs lower doses. The stimulation effect is observed in a narrow dose interval which is the same for the plant species studied: barley, wheat, pea, maize and melon

  1. Dynamic flowgraph modeling of process and control systems of a nuclear-based hydrogen production plant

    Energy Technology Data Exchange (ETDEWEB)

    Al-Dabbagh, Ahmad W. [Faculty of Engineering and Applied Science, University of Ontario Institute of Technology, 2000 Simcoe Street North, Oshawa, Ontario (Canada); Lu, Lixuan [Faculty of Energy Systems and Nuclear Science, Faculty of Engineering and Applied Science, University of Ontario Institute of Technology, 2000 Simcoe Street North, Oshawa, Ontario (Canada)

    2010-09-15

    Modeling and analysis of system reliability facilitate the identification of areas of potential improvement. The Dynamic Flowgraph Methodology (DFM) is an emerging discrete modeling framework that allows for capturing time dependent behaviour, switching logic and multi-state representation of system components. The objective of this research is to demonstrate the process of dynamic flowgraph modeling of a nuclear-based hydrogen production plant with the copper-chlorine (Cu-Cl) cycle. Modeling of the thermochemical process of the Cu-Cl cycle in conjunction with a networked control system proposed for monitoring and control of the process is provided. This forms the basis for future component selection. (author)

  2. Systematic generation of rules for nuclear power plant diagnostics

    International Nuclear Information System (INIS)

    Reifman, J.; Lee, J.C.

    1988-01-01

    The knowledge base of an expert system is generally represented by a set of heuristic rules derived from the expert's own experience and judgmental knowledge. These heuristic or production rules are cast as if (condition), then (consequence) statements, and represent, for nuclear power plant diagnostic systems, information connecting symptoms to failures. In this paper, the authors apply an entropy minimax pattern recognition algorithm to automate the process of extracting and encoding knowledge into a set of rules. Knowledge is extracted by recognizing patterns in plant parameters or symptoms associated with failures or transient events, and is encoded by casting the discovered patterns as production rules. The paper discusses how the proposed method can systematically generate rules that characterize failure of pressurizer components based on transient events analyzed with a pressurizer components based on transient events analyzed with a pressurizer water reactor simulator program

  3. Hydraulic plant generation forecasting in Colombian power market using ANFIS

    Energy Technology Data Exchange (ETDEWEB)

    Moreno, Julian [Computer Science Department, Carrera 80 No. 65-223 Bloque M8A, Universidad Nacional de Colombia, Medellin (Colombia)

    2009-05-15

    In this paper an ANFIS model (adaptive neuro-fuzzy inference system) is proposed to forecast the monthly ideal generation of an agent with a hydraulic plant within the Colombian power market. The proposed model considers several factors as the plant's reservoir level, the expected hydraulic contributions of the rivers which feed it, and the expected weather conditions represented by the SST anomaly forecast in Nino 3.4 zone. The fitness of such model is measured with real data of a particular agent from period 2002-2007 and it is compared against a multiple linear regression model. The obtained results show a considerable decrease of the mean percentage error, which is an evidence of its validity and possible application to other agents. (author)

  4. Hydraulic plant generation forecasting in Colombian power market using ANFIS

    International Nuclear Information System (INIS)

    Moreno, Julian

    2009-01-01

    In this paper an ANFIS model (adaptive neuro-fuzzy inference system) is proposed to forecast the monthly ideal generation of an agent with a hydraulic plant within the Colombian power market. The proposed model considers several factors as the plant's reservoir level, the expected hydraulic contributions of the rivers which feed it, and the expected weather conditions represented by the SST anomaly forecast in Nino 3.4 zone. The fitness of such model is measured with real data of a particular agent from period 2002-2007 and it is compared against a multiple linear regression model. The obtained results show a considerable decrease of the mean percentage error, which is an evidence of its validity and possible application to other agents. (author)

  5. How is Electricity Generated from Nuclear Power Plant

    International Nuclear Information System (INIS)

    Lajnef, D.

    2015-01-01

    Nuclear power is a proven, safe and clean source of power generation. A nuclear power plant is a thermal power station in which the heat source is a nuclear reactor. As is typical in all conventional thermal power stations the heat is used to generate steam which drives a steam turbine: the energy released from continuous fission of the atoms of the fuel is harnessed as heat in either a gas or water, and is used to produce steam. Nuclear Reactors are classified by several methods. It can be classified by type of nuclear reaction, by the moderator material, by coolant or by generation. There are several components common to most types of reactors: fuel, moderator, control rods, coolant, and containment. Nuclear reactor technology has been under continuous development since the first commercial exploitation of civil nuclear power in the 1950s. We can mention seven key reactor attributes that illuminate the essential differences between the various generations of reactors: cost effectiveness, safety, security and non-proliferation, fuel cycle, grid appropriateness and Economics. Today there are about 437 nuclear power reactors that are used to generate electricity in about 30 countries around the world. (author)

  6. Modular steam generator for use in nuclear power plants

    International Nuclear Information System (INIS)

    Cella, A.

    1979-01-01

    An improved steam generator for a PWR is described. A turbine generator is driven by the steam output of the steam generator to provide electrical power. The improvement provides vertically assemblable modules which are removably mounted together in sealing relationship. The modules comprising a base module, a tube bundle module removably mountable on the base module in sealing relationship, and an uppermost dryer module removably mountable on the tube bundle module in sealing relationship. Ready access to and removal of the tube bundle module in situ from the nuclear power plant steam generator is facilitated. The dryer module contains moisture separator for drying the generated steam. The base module, upon which the associated weight of the vertically assembled dryer module and tube bundle module are supported, contains the inlet and outlet for the heat exchange fluid. The tube bundle module contains the tube bundle through which the heat exchange fluid flows as well as an inlet for feedwater. The tube sheet serves as a closure flange for the tube bundle module, with the associated weight of the vertically assembled dryer module and tube bundle module on the tube sheet closure flange effectuating the sealing relationship between the base module and the tube bundle module for facilitating closure

  7. Hydrogen generation from Al-NiCl2/NaBH4 mixture affected by lanthanum metal.

    Science.gov (United States)

    Sun, Wen Qiang; Fan, Mei-Qiang; Fei, Yong; Pan, Hua; Wang, Liang Liang; Yao, Jun

    2012-01-01

    The effect of La on Al/NaBH(4) hydrolysis was elaborated in the present paper. Hydrogen generation amount increases but hydrogen generation rate decreases with La content increasing. There is an optimized composition that Al-15 wt% La-5 wt% NiCl(2)/NaBH(4) mixture (Al-15 wt% La-5 wt% NiCl(2)/NaBH(4) weight ratio, 1 : 3) has 126 mL g(-1 )min(-1) maximum hydrogen generation rate and 1764 mL g(-1) hydrogen generation amount within 60 min. The efficiency is 88%. Combined with NiCl(2), La has great effect on NaBH(4) hydrolysis but has little effect on Al hydrolysis. Increasing La content is helpful to decrease the particle size of Al-La-NiCl(2) in the milling process, which induces that the hydrolysis byproduct Ni(2)B is highly distributed into Al(OH)(3) and the catalytic reactivity of Ni(2)B/Al(OH)(3) is increased therefore. But hydrolysis byproduct La(OH)(3) deposits on Al surface and leads to some side effect. The Al-La-NiCl(2)/NaBH(4) mixture has good stability in low temperature and its hydrolytic performance can be improved with increasing global temperature. Therefore, the mixture has good safety and can be applied as on board hydrogen generation material.

  8. Hydrogen gains further momentum

    International Nuclear Information System (INIS)

    Anon.

    2017-01-01

    As first industrial production projects should become a reality in the next few years, hydrogen as a source of energy will find important applications with mobility, which momentum is rapid and irresistible. Next steps will be the (large capacity) storage of hydrogen associated to power-to-gas systems and the generalization of renewable energies. This document presents 5 articles, which themes are: Description and explanation of the process of hydrogen production; Presentation of the H2V project for the construction, in Normandy, of the first operational industrial hydrogen production plant using electric power 100 pc generated by renewable energies; The conversion of electric power from renewable energies through hydrogen storage and fuel cells for buildings applications (Sylfen project); The development of a reversible fuel cell at Mines-Paris Tech University, that will be adapted to the storage of renewable electric power; Hydrogen as a lever for the development of zero-emission vehicles, from trucks to cars and bicycles

  9. Water electrolysis with a conducting carbon cloth: subthreshold hydrogen generation and superthreshold carbon quantum dot formation.

    Science.gov (United States)

    Biswal, Mandakini; Deshpande, Aparna; Kelkar, Sarika; Ogale, Satishchandra

    2014-03-01

    A conducting carbon cloth, which has an interesting turbostratic microstructure and functional groups that are distinctly different from other ordered forms of carbon, such as graphite, graphene, and carbon nanotubes, was synthesized by a simple one-step pyrolysis of cellulose fabric. This turbostratic disorder and surface chemical functionalities had interesting consequences for water splitting and hydrogen generation when such a cloth was used as an electrode in the alkaline electrolysis process. Importantly, this work also gives a new twist to carbon-assisted electrolysis. During electrolysis, the active sites in the carbon cloth allow slow oxidation of its surface to transform the surface groups from COH to COOH and so forth at a voltage as low as 0.2 V in a two-electrode system, along with platinum as the cathode, instead of 1.23 V (plus overpotential), which is required for platinum, steel, or even graphite anodes. The quantity of subthreshold hydrogen evolved was 24 mL cm(-2)  h(-1) at 1 V. Interestingly, at a superthreshold potential (>1.23 V+overpotential), another remarkable phenomenon was found. At such voltages, along with the high rate and quantity of hydrogen evolution, rapid exfoliation of the tiny nanoscale (5-7 nm) units of carbon quantum dots (CQDs) are found in copious amounts due to an enhanced oxidation rate. These CQDs show bright-blue fluorescence under UV light. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Multi-dimensional Analysis Method of Hydrogen Combustion in the Containment of a Nuclear Power Plant

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jongtae; Hong, Seongwan [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Kim, Gun Hong [Kyungwon E and C Co., Seongnam (Korea, Republic of)

    2014-05-15

    The most severe case is the occurrence of detonation, which induces a few-fold greater pressure load on the containment wall than a deflagration flame. The occurrence of a containment-wise global detonation is prohibited by a national regulation. The compartments located in the flow path such as steam generator compartment, annular compartment, and dome region are likely to have highly-concentrated hydrogen. If it is found that hydrogen concentration in any compartment is far below a detonation criterion during an accident progression, it can be thought that the occurrence of a detonative explosion in a compartment is excluded. However, if it is not, it is necessary to evaluate the characteristics of flame acceleration in the containment. The possibility of a flame transition from a deflagration to a detonation (DDT) can be evaluated from a calculated hydrogen distribution in a compartment by using sigma-lambda criteria. However, this method can provide a very conservative result because the geometric characteristics of a real compartment are not considered well. In order to evaluate the containment integrity from a threat of a hydrogen explosion, it is necessary to establish an integrated evaluation system, which includes a lumped-parameter and detail analysis methods. In this study, a method for the multi-dimensional analysis of hydrogen combustion is proposed to mechanistically evaluate the flame acceleration characteristics with a geometric effect. The geometry of the containment is modeled 3-dimensionally using a CAD tool. To resolve a propagating flame front, an adaptive mesh refinement method is coupled with a combustion analysis solver.

  11. 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)

  12. Entropy generation minimization: A practical approach for performance evaluation of temperature cascaded co-generation plants

    KAUST Repository

    Myat, Aung; Thu, Kyaw; Kim, Youngdeuk; Saha, Bidyut Baran; Ng, K. C.

    2012-01-01

    We present a practical tool that employs entropy generation minimization (EGM) approach for an in-depth performance evaluation of a co-generation plant with a temperature-cascaded concept. Co-generation plant produces useful effect production sequentially, i.e., (i) electricity from the micro-turbines, (ii) low pressure steam at 250 °C or about 8-10 bars, (iii) cooling capacity of 4 refrigeration tones (Rtons) and (iv) dehumidification of outdoor air for air conditioned space. The main objective is to configure the most efficient configuration of producing power and heat. We employed entropy generation minimization (EGM) which reflects to minimize the dissipative losses and maximize the cycle efficiency of the individual thermally activated systems. The minimization of dissipative losses or EGM is performed in two steps namely, (i) adjusting heat source temperatures for the heat-fired cycles and (ii) the use of Genetic Algorithm (GA), to seek out the sensitivity of heat transfer areas, flow rates of working fluids, inlet temperatures of heat sources and coolant, etc., over the anticipated range of operation to achieve maximum efficiency. With EGM equipped with GA, we verified that the local minimization of entropy generation individually at each of the heat-activated processes would lead to the maximum efficiency of the system. © 2012.

  13. Entropy generation minimization: A practical approach for performance evaluation of temperature cascaded co-generation plants

    KAUST Repository

    Myat, Aung

    2012-10-01

    We present a practical tool that employs entropy generation minimization (EGM) approach for an in-depth performance evaluation of a co-generation plant with a temperature-cascaded concept. Co-generation plant produces useful effect production sequentially, i.e., (i) electricity from the micro-turbines, (ii) low pressure steam at 250 °C or about 8-10 bars, (iii) cooling capacity of 4 refrigeration tones (Rtons) and (iv) dehumidification of outdoor air for air conditioned space. The main objective is to configure the most efficient configuration of producing power and heat. We employed entropy generation minimization (EGM) which reflects to minimize the dissipative losses and maximize the cycle efficiency of the individual thermally activated systems. The minimization of dissipative losses or EGM is performed in two steps namely, (i) adjusting heat source temperatures for the heat-fired cycles and (ii) the use of Genetic Algorithm (GA), to seek out the sensitivity of heat transfer areas, flow rates of working fluids, inlet temperatures of heat sources and coolant, etc., over the anticipated range of operation to achieve maximum efficiency. With EGM equipped with GA, we verified that the local minimization of entropy generation individually at each of the heat-activated processes would lead to the maximum efficiency of the system. © 2012.

  14. 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

  15. Operating experience with diesel generators in Belgian nuclear power plants

    Energy Technology Data Exchange (ETDEWEB)

    Merny, R. [Association Vincotte, Avenue du Roi 157, B-1060 Bruxelles/Brussels (Belgium)

    1986-02-15

    Various problems have occurred on the diesel generators in the Belgian nuclear power plants, independently of the D.G. manufacturer or from the operating crew. Furthermore no individual part of the D.G. can be incriminated as being the main cause of the incidents. The incidents reported in this paper are chosen because of the importance for the safety or for the long repair period. The unavailability of a D.G. can only be detected by periodic tests and controls. Combined with a good preventive maintenance, the risks of incidents can be reduced. (author)

  16. Operating experience with diesel generators in Belgian nuclear power plants

    International Nuclear Information System (INIS)

    Merny, R.

    1986-01-01

    Various problems have occurred on the diesel generators in the Belgian nuclear power plants, independently of the D.G. manufacturer or from the operating crew. Furthermore no individual part of the D.G. can be incriminated as being the main cause of the incidents. The incidents reported in this paper are chosen because of the importance for the safety or for the long repair period. The unavailability of a D.G. can only be detected by periodic tests and controls. Combined with a good preventive maintenance, the risks of incidents can be reduced. (author)

  17. Generation IV nuclear energy systems: road map and concepts. 2. Generation II Measurement Systems for Generation IV Nuclear Power Plants

    International Nuclear Information System (INIS)

    Miller, Don W.

    2001-01-01

    Instrumentation and Control (I and C) systems in current operating plants have not changed appreciably since their original design in the 1950's. These systems depend on a variety of traditional process and radiation sensors for the measurement of safety and control variables such as temperature, pressure, and neutron flux. To improve their performance and to make them more robust, many plant control systems have been upgraded from analog to digital; most of them continue to utilize traditional single-input single-output architecture. Transmission of data, for the most part, continues to employ large coaxial cables. These cables are not the small cables used in a laboratory (i.e., RG-58 or RG-59). Because of concern about electromagnetic and radio frequency interference and other environmental effects, bulky triax cables, which are cables with two outer shields separated by an insulator, are used. In a nuclear plant there are literally miles of cables and hundreds of specialized penetrations for cables going through containment or pressure vessel walls. The I and C systems in the advanced light water reactor (ALWR) designs, i.e., Generation III reactors, do employ more advanced technology than current plants; however, they do not incorporate new technology on a broad scale. This in part is a consequence of the ALWR design philosophy that discouraged use of advanced technology if current technology was adequate. As a consequence, the I and C systems in the ALWRs continue to make use of current technology. There are two exceptions, however, which include the broad use of software-based digital systems and fiber optics for signal isolation and data transmission in nonradioactive areas. The ALWR design philosophy was a justifiably low-risk approach when considering the overall objective of 'capturing' lessons learned from current operating plants to design a plant that would exhibit performance superior to current plants and would be relatively easy to license without

  18. Multi-state system in a fault tree analysis of a nuclear based thermochemical hydrogen plant

    International Nuclear Information System (INIS)

    Zhang, Y.

    2008-01-01

    Nuclear-based hydrogen generation is a promising way to supply hydrogen for this large market in the future. This thesis focuses on one of the most promising methods, a thermochemical Cu-Cl cycle, which is currently under development by UOIT, Atomic Energy of Canada Limited (AECL) and the Argonne National Laboratory (ANL). The safety issues of the Cu-Cl cycle are addressed in this thesis. An investigation of major accident scenarios shows that potential tragedies can be avoided with effective risk analysis and safety management programs. As a powerful and systematic tool, fault tree analysis (FTA) is adapted to the particular needs of the Cu-Cl system. This thesis develops a new method that combines FTA with a reliability analysis tool, multi-state system (MSS), to improve the accuracy of FTA and also improve system reliability. (author)

  19. Hydrogen system (hydrogen fuels feasibility)

    International Nuclear Information System (INIS)

    Guarna, S.

    1991-07-01

    This feasibility study on the production and use of hydrogen fuels for industry and domestic purposes includes the following aspects: physical and chemical properties of hydrogen; production methods steam reforming of natural gas, hydrolysis of water; liquid and gaseous hydrogen transportation and storage (hydrogen-hydride technology); environmental impacts, safety and economics of hydrogen fuel cells for power generation and hydrogen automotive fuels; relevant international research programs

  20. Hydrogen sulfide: a new endogenous player in an old mechanism of plant tolerance to high salinity

    Directory of Open Access Journals (Sweden)

    Cristiane J. da-Silva

    2017-10-01

    Full Text Available ABSTRACT High salinity affects plants due to stimulation of osmotic stress. Cell signaling triggered by nitric oxide (NO and hydrogen sulfide (H2S activates a cascade of biochemical events that culminate in plant tolerance to abiotic and biotic stresses. For instance, the NO/H2S-stimulated biochemical events that occur in plants during response to high salinity include the control of reactive oxygen species, activation of antioxidant system, accumulation of osmoprotectants in cytosol, induction of K+ uptake and Na+ cell extrusion or its vacuolar compartmentation among others. This review is a compilation of what we have learned in the last 10 years about NO participation during cell signaling in response to high salinity as well as the role of H2S, a new player in the mechanism of plant tolerance to salt stress. The main sources of NO and H2S in plant cells is also discussed together with the evidence of interplay between both signaling molecules during response to stress.

  1. Efficiency Evaluation of a Photovoltaic System Simultaneously Generating Solar Electricity and Hydrogen for Energy Storage

    Directory of Open Access Journals (Sweden)

    Abermann S.

    2012-10-01

    Full Text Available The direct combination of a photovoltaic system with an energy storage component appears desirable since it produces and stores electrical energy simultaneously, enabling it to compensate power generation fluctuations and supply sufficient energy during low- or non-irradiation periods. A novel concept based on hydrogenated amorphous silicon (a-Si:H triple-junction solar cells, as for example a-Si:H/a-SiGe:H/a-SiGe:H, and a solar water splitting system integrating a polymer electrolyte membrane (PEM electrolyser is presented. The thin film layer-by-layer concept allows large-area module fabrication applicable to buildings, and exhibits strong cost-reduction potential as compared to similar concepts. The evaluation shows that it is possible to achieve a sufficient voltage of greater than 1.5 V for effective water splitting with the a-Si based solar cell. Nevertheless, in the case of grid-connection, the actual energy production cost for hydrogen storage by the proposed system is currently too high.

  2. Hydrogen generation from decomposition of hydrous hydrazine over Ni-Ir/CeO2 catalyst

    Directory of Open Access Journals (Sweden)

    Hongbin Dai

    2017-02-01

    Full Text Available The synthesis of highly active and selective catalysts is the central issue in the development of hydrous hydrazine (N2H4·H2O as a viable hydrogen carrier. Herein, we report the synthesis of bimetallic Ni-Ir nanocatalyts supported on CeO2 using a one-pot coprecipitation method. A combination of XRD, HRTEM and XPS analyses indicate that the Ni-Ir/CeO2 catalyst is composed of tiny Ni-Ir alloy nanoparticles with an average size of around 4 nm and crystalline CeO2 matrix. The Ni-Ir/CeO2 catalyst exhibits high catalytic activity and excellent selectivity towards hydrogen generation from N2H4·H2O at mild temperatures. Furthermore, in contrast to previously reported Ni-Pt catalysts, the Ni-Ir/CeO2 catalyst shows an alleviated requirement on alkali promoter to achieve its optimal catalytic performance.

  3. A direct recursive residue generation method: application to photoionization of hydrogen in static electric fields

    International Nuclear Information System (INIS)

    Karlsson, H.O.; Goscinski, O.

    1994-01-01

    In studies of hydrogenic systems via the recursive residue generation method (RRGM) the major bottleneck is the matrix vector product HC, between the Hamiltonian matrix H and a Lanczos vector C. For highly excited states and/or strong perturbations the size of H grows fast leading to storage problems. By making use of direct methods, i.e. avoidance of explicit construction of large Hamiltonian matrices, such problems can be overcome. Utilizing the underlying analytical properties of the Laguerre basis e -λr L k 2l+2 (2λr) a direct RRGM (D-RRGM) for the unperturbed hydrogenic Hamiltonian is derived, changing the storage needs from scaling as N 2 to 4N where N is the number of radial functions for each factorized H o (l,m) block with the possibility of parallel processing. A further computational simplification is introduced by putting the expression for the photoionization (PI) cross section in the rational form conventionally used in the representation of density of states (DOS). This allows the construction of the PI cross section directly from the tridiagonal Lanczos matrix avoiding the explicit calculation of individual eigen values and eigenvectors. (Author)

  4. Exergoeconomic estimates for a novel zero-emission process generating hydrogen and electric power

    International Nuclear Information System (INIS)

    Tsatsaronis, George; Kapanke, Kerstin; Maria Blanco Marigorta, Ana

    2008-01-01

    This paper presents the exergoeconomic analysis of a novel process generating electric energy and hydrogen. Coal and high-temperature heat are used as input energy to the process. The process is a true 'zero-emission process' because (a) no NO X is formed during coal combustion with sulfuric acid, and (b) the combustion products CO 2 and SO 2 are removed separately as compressed liquids from the overall process. The process cycle is based on two chemical reactions. The first reaction takes place in an electrolytic cell and delivers the hydrogen product. In the second step, coal reacts with sulfuric acid in a high-pressure combustion reactor. The combustion gas is expanded in a gas turbine to produce electric power. The combustion products are compressed and separated so that almost pure CO 2 can be removed from the cycle. The overall process is characterized by very high energetic and exergetic efficiencies. However, the overall process is very capital intensive. The electrolytic cell dominates the costs associated with the overall process. Detailed results of the thermodynamic simulation, the economic and the exergoeconomic analyses of the process including estimates of the product costs are presented

  5. Reducing Risk for the Next Generation Nuclear Plant

    Energy Technology Data Exchange (ETDEWEB)

    John M. Beck II; Harold J. Heydt; Emmanuel O. Opare; Kyle B. Oswald

    2010-07-01

    The Next Generation Nuclear Plant (NGNP) Project, managed by the Idaho National Laboratory (INL), is directed by the Energy Policy Act of 2005, to research, develop, design, construct, and operate a prototype forth generation nuclear reactor to meet the needs of the 21st Century. As with all large projects developing and deploying new technologies, the NGNP has numerous risks that need to be identified, tracked, mitigated, and reduced in order for successful project completion. A Risk Management Plan (RMP) was created to outline the process the INL is using to manage the risks and reduction strategies for the NGNP Project. Integral to the RMP is the development and use of a Risk Management System (RMS). The RMS is a tool that supports management and monitoring of the project risks. The RMS does not only contain a risk register, but other functionality that allows decision makers, engineering staff, and technology researchers to review and monitor the risks as the project matures.

  6. Reducing Risk for the Next Generation Nuclear Plant

    International Nuclear Information System (INIS)

    Beck, John M. II; Heydt, Harold J.; Opare, Emmanuel O.; Oswald, Kyle B.

    2010-01-01

    The Next Generation Nuclear Plant (NGNP) Project, managed by the Idaho National Laboratory (INL), is directed by the Energy Policy Act of 2005, to research, develop, design, construct, and operate a prototype forth generation nuclear reactor to meet the needs of the 21st Century. As with all large projects developing and deploying new technologies, the NGNP has numerous risks that need to be identified, tracked, mitigated, and reduced in order for successful project completion. A Risk Management Plan (RMP) was created to outline the process the INL is using to manage the risks and reduction strategies for the NGNP Project. Integral to the RMP is the development and use of a Risk Management System (RMS). The RMS is a tool that supports management and monitoring of the project risks. The RMS does not only contain a risk register, but other functionality that allows decision makers, engineering staff, and technology researchers to review and monitor the risks as the project matures.

  7. Probabilistic consequence assessment of hydrogen sulphide releases from a heavy water plant

    International Nuclear Information System (INIS)

    Baynes, C.J.

    1986-05-01

    This report provides a summary of work carried out on behalf of the Atomic Energy Control Board, concerned with the consequences of accidental releases to the atmosphere of hydrogen sulphide (H 2 S) at a heavy water plant. In this study, assessments of consequences are made in terms of the probabilities of a range of possible outcomes, i.e., numbers of fatalities, given a certain release scenario. The report describes the major features of a computer model which was developed to calculate the consequences and their associated probabilities, and the major input data used in applying the model to a consequence assessment of the Bruce heavy water plant (HWP) in Ontario. The results of the sensitivity analyses of the model are summarized. Finally, the results of the consequence assessments of 43 accidental release scenarios at the Bruce HWP are summarized, together with a number of conclusions which were drawn from these results regarding the predicted consequences and the factors which influence them

  8. Prediction of hydrogen concentration in nuclear power plant containment under severe accidents using cascaded fuzzy neural networks

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Geon Pil; Kim, Dong Yeong; Yoo, Kwae Hwan; Na, Man Gyun, E-mail: magyna@chosun.ac.kr

    2016-04-15

    Highlights: • We present a hydrogen-concentration prediction method in an NPP containment. • The cascaded fuzzy neural network (CFNN) is used in this prediction model. • The CFNN model is much better than the existing FNN model. • This prediction can help prevent severe accidents in NPP due to hydrogen explosion. - Abstract: Recently, severe accidents in nuclear power plants (NPPs) have attracted worldwide interest since the Fukushima accident. If the hydrogen concentration in an NPP containment is increased above 4% in atmospheric pressure, hydrogen combustion will likely occur. Therefore, the hydrogen concentration must be kept below 4%. This study presents the prediction of hydrogen concentration using cascaded fuzzy neural network (CFNN). The CFNN model repeatedly applies FNN modules that are serially connected. The CFNN model was developed using data on severe accidents in NPPs. The data were obtained by numerically simulating the accident scenarios using the MAAP4 code for optimized power reactor 1000 (OPR1000) because real severe accident data cannot be obtained from actual NPP accidents. The root-mean-square error level predicted by the CFNN model is below approximately 5%. It was confirmed that the CFNN model could accurately predict the hydrogen concentration in the containment. If NPP operators can predict the hydrogen concentration in the containment using the CFNN model, this prediction can assist them in preventing a hydrogen explosion.

  9. Nuclear power and hydrogen

    International Nuclear Information System (INIS)

    Welch, Robert.

    1982-06-01

    Ontario has been using CANDU reactors to produce electricity since 1962. The province does not have an electricity shortage, but it does have a shortage of liquid fuels. The government of Ontario is encouraging research into the production of hydrogen using electricity generated by a dedicated nuclear plant, and the safe and economical use of hydrogen both in the production of synthetic petroleum fuels and as a fuel in its own right

  10. Gas generation from radiolytic attack of TRU-contaminated hydrogenous waste

    International Nuclear Information System (INIS)

    Zerwekh, A.

    1979-06-01

    In 1970, the Waste Management and Transportation Division of the Atomic Energy Commission ordered a segregation of transuranic (TRU)-contaminated solid wastes. Those below a contamination level of 10 nCi/g could still be buried; those above had to be stored retrievably for 20 y. The possibility that alpha-radiolysis of hydrogenous materials might produce toxic, corrosive, and flammable gases in retrievably stored waste prompted an investigation of gas identities and generation rates in the laboratory and field. Typical waste mixtures were synthesized and contaminated for laboratory experiments, and drums of actual TRU-contaminated waste were instrumented for field testing. Several levels of contamination were studied, as well as pressure, temperature, and moisture effects. G (gas) values were determined for various waste matrices, and degradation products were examined

  11. Vibrational excitation of hydrogen molecules by two-photon absorption and third-harmonic generation

    Science.gov (United States)

    Miyamoto, Yuki; Hara, Hideaki; Hiraki, Takahiro; Masuda, Takahiko; Sasao, Noboru; Uetake, Satoshi; Yoshimi, Akihiro; Yoshimura, Koji; Yoshimura, Motohiko

    2018-01-01

    We report the coherent excitation of the vibrational state of hydrogen molecules by two-photon absorption and the resultant third-harmonic generation (THG). Parahydrogen molecules cooled by liquid nitrogen are irradiated by mid-infrared nanosecond pulses at 4.8 μm with a nearly Fourier-transform-limited linewidth. The first excited vibrational state of parahydrogen is populated by two-photon absorption of the mid-infrared photons. Because of the narrow linewidth of the mid-infrared pulses, coherence between the ground and excited states is sufficient to induce higher-order processes. Near-infrared photons from the THG are observed at 1.6 μm. The dependence of the intensity of the near-infrared radiation on mid-infrared pulse energy, target pressure, and cell length is determined. We used a simple formula for THG with consideration of realistic experimental conditions to explain the observed results.

  12. Liquid hydrogen in Japan

    Energy Technology Data Exchange (ETDEWEB)

    Yasumi, S. [Iwatani Corp., Osaka (Japan). Dept. of Overseas Business Development

    2009-07-01

    Japan's Iwatani Corporation has focused its attention on hydrogen as the ultimate energy source in future. Unlike the United States, hydrogen use and delivery in liquid form is extremely limited in the European Union and in Japan. Iwatani Corporation broke through industry stereotypes by creating and building Hydro Edge Co. Ltd., Japan's largest liquid hydrogen plant. It was established in 2006 as a joint venture between Iwatani and Kansai Electric Power Group in Osaka. Hydro Edge is Japan's first combined liquid hydrogen and ASU plant, and is fully operational. Liquid oxygen, liquid nitrogen and liquid argon are separated from air using the cryogenic energy of liquefied natural gas fuel that is used for power generation. Liquid hydrogen is produced efficiently and simultaneously using liquid nitrogen. Approximately 12 times as much hydrogen in liquid form can be transported and supplied as pressurized hydrogen gas. This technology is a significant step forward in the dissemination and expansion of hydrogen in a hydrogen-based economy.

  13. Mitigation of Hydrogen Gas Generation from the Reaction of Uranium Metal with Water in K Basin Sludge and Sludge Waste Forms

    Energy Technology Data Exchange (ETDEWEB)

    Sinkov, Sergey I.; Delegard, Calvin H.; Schmidt, Andrew J.

    2011-06-08

    Prior laboratory testing identified sodium nitrate and nitrite to be the most promising agents to minimize hydrogen generation from uranium metal aqueous corrosion in Hanford Site K Basin sludge. Of the two, nitrate was determined to be better because of higher chemical capacity, lower toxicity, more reliable efficacy, and fewer side reactions than nitrite. The present lab tests were run to determine if nitrate’s beneficial effects to lower H2 generation in simulated and genuine sludge continued for simulated sludge mixed with agents to immobilize water to help meet the Waste Isolation Pilot Plant (WIPP) waste acceptance drainable liquid criterion. Tests were run at ~60°C, 80°C, and 95°C using near spherical high-purity uranium metal beads and simulated sludge to emulate uranium-rich KW containerized sludge currently residing in engineered containers KW-210 and KW-220. Immobilization agents tested were Portland cement (PC), a commercial blend of PC with sepiolite clay (Aquaset II H), granulated sepiolite clay (Aquaset II G), and sepiolite clay powder (Aquaset II). In all cases except tests with Aquaset II G, the simulated sludge was mixed intimately with the immobilization agent before testing commenced. For the granulated Aquaset II G clay was added to the top of the settled sludge/solution mixture according to manufacturer application directions. The gas volumes and compositions, uranium metal corrosion mass losses, and nitrite, ammonia, and hydroxide concentrations in the interstitial solutions were measured. Uranium metal corrosion rates were compared with rates forecast from the known uranium metal anoxic water corrosion rate law. The ratios of the forecast to the observed rates were calculated to find the corrosion rate attenuation factors. Hydrogen quantities also were measured and compared with quantities expected based on non-attenuated H2 generation at the full forecast anoxic corrosion rate to arrive at H2 attenuation factors. The uranium metal

  14. Mitigation of Hydrogen Gas Generation from the Reaction of Uranium Metal with Water in K Basin Sludge and Sludge Waste Forms

    International Nuclear Information System (INIS)

    Sinkov, Sergey I.; Delegard, Calvin H.; Schmidt, Andrew J.

    2011-01-01

    Prior laboratory testing identified sodium nitrate and nitrite to be the most promising agents to minimize hydrogen generation from uranium metal aqueous corrosion in Hanford Site K Basin sludge. Of the two, nitrate was determined to be better because of higher chemical capacity, lower toxicity, more reliable efficacy, and fewer side reactions than nitrite. The present lab tests were run to determine if nitrate's beneficial effects to lower H2 generation in simulated and genuine sludge continued for simulated sludge mixed with agents to immobilize water to help meet the Waste Isolation Pilot Plant (WIPP) waste acceptance drainable liquid criterion. Tests were run at ∼60 C, 80 C, and 95 C using near spherical high-purity uranium metal beads and simulated sludge to emulate uranium-rich KW containerized sludge currently residing in engineered containers KW-210 and KW-220. Immobilization agents tested were Portland cement (PC), a commercial blend of PC with sepiolite clay (Aquaset II H), granulated sepiolite clay (Aquaset II G), and sepiolite clay powder (Aquaset II). In all cases except tests with Aquaset II G, the simulated sludge was mixed intimately with the immobilization agent before testing commenced. For the granulated Aquaset II G clay was added to the top of the settled sludge/solution mixture according to manufacturer application directions. The gas volumes and compositions, uranium metal corrosion mass losses, and nitrite, ammonia, and hydroxide concentrations in the interstitial solutions were measured. Uranium metal corrosion rates were compared with rates forecast from the known uranium metal anoxic water corrosion rate law. The ratios of the forecast to the observed rates were calculated to find the corrosion rate attenuation factors. Hydrogen quantities also were measured and compared with quantities expected based on non-attenuated H2 generation at the full forecast anoxic corrosion rate to arrive at H2 attenuation factors. The uranium metal

  15. Design of nuclear power generation plants adopting model engineering method

    International Nuclear Information System (INIS)

    Waki, Masato

    1983-01-01

    The utilization of model engineering as the method of design has begun about ten years ago in nuclear power generation plants. By this method, the result of design can be confirmed three-dimensionally before actual production, and it is the quick and sure method to meet the various needs in design promptly. The adoption of models aims mainly at the improvement of the quality of design since the high safety is required for nuclear power plants in spite of the complex structure. The layout of nuclear power plants and piping design require the model engineering to arrange rationally enormous quantity of things in a limited period. As the method of model engineering, there are the use of check models and of design models, and recently, the latter method has been mainly taken. The procedure of manufacturing models and engineering is explained. After model engineering has been completed, the model information must be expressed in drawings, and the automation of this process has been attempted by various methods. The computer processing of design is in progress, and its role is explained (CAD system). (Kako, I.)

  16. The human factors issue in the next generation nuclear plants

    International Nuclear Information System (INIS)

    Noviello, L.; Bolognini, G.; Nobile, M.

    1992-01-01

    The national Energy Plan approved by the Italian Government in 1988, soon after the public referendum on nuclear issues held in the wake of the Chernobyl accident, requested the start of a research program to study next generation nuclear plants. These new reactors should feature some important and innovative characteristics to have a chance to be considered for future constructions, should the politicians decide the conditions for such a step are again re-established in Italy. The most important of these characteristics is certainly the fact that no evaluation nor land set a-side shall be required even in case of the most severe conceivable accident. This challenging objective should be reached through: a) the simplification of the nuclear plant as a whole b) the extensive use of passive components and/or inherent safety features in the design of the engineering safeguard systems c) a containment designed to cope with any conceivable accident sequence without releasing any major quantity of radioactive products into the environment. d) the upgrading of the man-machine interface and the introduction of computerized aids both for operational and maintenance activities. This paper deals in particular with the improvements, described in point d), that aim at greatly reducing the probability of human errors, widely recognized as one of the most important aspects to be pursued to increase nuclear plant safety. (author)

  17. Generation of hydrogen peroxide from San Joaquin Valley particles in a cell-free solution

    Directory of Open Access Journals (Sweden)

    H. Shen

    2011-01-01

    Full Text Available Epidemiological studies have shown a correlation between exposure to ambient particulate matter (PM and adverse health effects. One proposed mechanism of PM-mediated health effects is the generation of reactive oxygen species (ROS – e.g., superoxide (O2, hydrogen peroxide (HOOH, and hydroxyl radical (OH – followed by oxidative stress. There are very few quantitative, specific measures of individual ROS generated from PM, but this information would help to more quantitatively address the link between ROS and the health effects of PM. To address this gap, we quantified the generation of HOOH by PM collected at an urban (Fresno and rural (Westside site in the San Joaquin Valley (SJV of California during summer and winter from 2006 to 2009. HOOH was quantified by HPLC after extracting the PM in a cell-free, phosphate-buffered saline (PBS solution with or without 50 μM ascorbate (Asc. Our results show that the urban PM generally generates much more HOOH than the rural PM but that there is no apparent seasonal difference in HOOH generation. In nearly all of the samples the addition of a physiologically relevant concentration of Asc greatly enhances HOOH formation, but a few of the coarse PM samples were able to generate a considerable amount of HOOH in the absence of added Asc, indicating the presence of unknown reductants. Normalized by air volume, the fine PM (PM2.5 generally makes more HOOH than the corresponding coarse PM (PMcf, i.e., 2.5 to 10 μm, primarily because the mass concentration of PM2.5 is much higher than that of PMcf. However, normalized by PM mass, the coarse PM typically generates more HOOH than the fine PM. The amount of HOOH produced by SJV PM is reduced on average by (78 ± 15% when the transition metal chelator desferoxamine (DSF is added to the extraction solution, indicating that transition metals play a dominant role in HOOH

  18. Catalytic hydrolysis of ammonia borane for hydrogen generation using cobalt nanocluster catalyst supported on polydopamine functionalized multiwalled carbon nanotube

    International Nuclear Information System (INIS)

    Arthur, Ernest Evans; Li, Fang; Momade, Francis W.Y.; Kim, Hern

    2014-01-01

    Hydrogen was generated from ammonia borane complex by hydrolysis using cobalt nanocluster catalyst supported on polydopamine functionalized MWCNTs (multi-walled carbon nanotubes). The impregnation-chemical reduction method was used for the preparation of the supported catalyst. The nanocluster catalyst support was formed by in-situ oxidative polymerization of dopamine on the MWCNTs in alkaline solution at room temperature. The structural and physical–chemical properties of the nanocluster catalyst were characterized by FT-IR (Fourier transform infrared spectroscopy), EDX (energy-dispersive X-ray spectroscopy), SEM (scanning electron microscope), XRD (X-ray diffraction) and TEM (transmission electron microscopy). The nanocluster catalyst showed good catalytic activity for the hydrogen generation from aqueous ammonia borane complex. A reusability test to determine the practical usage of the catalyst was also investigated. The result revealed that the catalyst maintained an appreciable catalytic performance and stability in terms of its reusability after three cycle of reuse for the hydrolysis reaction. Also, the activation energy for the hydrolysis of ammonia borane complex was estimated to be 50.41 kJmol −1 , which is lower than the values of some of the reported catalyst. The catalyst can be considered as a promising candidate in developing highly efficient portable hydrogen generation systems such as PEMFC (proton exchange membrane fuel cells). - Highlights: • Co/Pdop-o-MWCNT (Pdop functionalized MWCNT supported cobalt nanocluster) catalyst was synthesized for hydrogen generation. • It is an active catalyst for hydrogen generation via hydrolysis of ammonia borane. • It showed good stability in terms of reusability for the hydrogen generation

  19. Enhanced hydrogen generation by hydrolysis of Mg doped with flower-like MoS2 for fuel cell applications

    Science.gov (United States)

    Huang, Minghong; Ouyang, Liuzhang; Liu, Jiangwen; Wang, Hui; Shao, Huaiyu; Zhu, Min

    2017-10-01

    In this work, flower-like MoS2 spheres are synthesized via a hydrothermal method and the catalytic activity of the as-prepared and bulk MoS2 on hydrolysis of Mg is systematically investigated for the first time. The Mg-MoS2 composites are prepared by ball milling and the hydrogen generation performances of the composites are investigated in 3.5% NaCl solution. The experimental results suggest that the as-prepared MoS2 exhibits better catalytic effect on hydrolysis of Mg compared to bulk MoS2. In particular, Mg-10 wt% MoS2 (as-prepared) composite milled for 1 h shows the best hydrogen generation properties and releases 90.4% of theoretical hydrogen generation capacity within 1 min at room temperature. The excellent catalytic effect of as-prepared MoS2 may be attributed to the following aspects: three-dimensional flower-like MoS2 architectures improve its dispersibility on Mg particles; make the composite more reactive; hamper the generated Mg(OH)2 from adhering to the surface of Mg; and increase the galvanic corrosion of Mg. In addition, a hydrogen generator based on the hydrolysis reaction of Mg-0.2 wt% MoS2 composite is manufactured and it can supply a maximum hydrogen flow rate of 2.5 L/min. The findings here demonstrate the as-prepared flower-like MoS2 can be a promising catalyst for hydrogen generation from Mg.

  20. Revamping of existent chlor-alkali plants for conversion of hydrogen to electricity, hydrogen community germination step

    Energy Technology Data Exchange (ETDEWEB)

    Iordache, Ioan; Laurentiu, Patularu [National R and D Institute for Cryogenics and Isotopic Technologies - ICSI, Rm. Valcea (Romania); Delfrate, Alessandro [UHDENORA SpA (Italy); Iordache, Mihaela [National R and D Institute for Industrial Ecology - ECOIND, Rm. Valcea (Romania)

    2010-07-01

    The transition towards hydrogen becoming widespread in future energy systems and may be one of the greatest social and technical challenges facing society. A wide range of stakeholders will need to work together over extended periods of time to make the sustainable hydrogen ''vision'' a reality. Community-based projects are seen as a route to stimulate the start of the transformation, leading to more widespread early adoption of these new technologies. Valcea have premises to develop some local projects in order to become a Hydrogen Community. This ''Community'' fulfills both an economic-technical background and a scientifically potential. (orig.)

  1. Photocatalytic hydrogen generation with Ag-loaded LiNbO3

    Indian Academy of Sciences (India)

    Administrator

    rhodamine B decomposition under solar illumination was also reported (Stock ... photocatalytic hydrogen production. ... lytic hydrogen production from a methanol aqueous solu- .... estimated bandgap energy of Nb2O5 and LiNbO3 samples.

  2. Simultaneous Hydrogen Generation and Waste Acid Neutralization in a Reverse Electrodialysis System

    KAUST Repository

    Hatzell, Marta C.; Zhu, Xiuping; Logan, Bruce E.

    2014-01-01

    power and hydrogen gas using waste heat-derived solutions, but high electrode overpotentials limit system performance. We show here that an ammonium bicarbonate (AmB) RED system can achieve simultaneous waste acid neutralization and in situ hydrogen

  3. Generation IV nuclear energy systems and hydrogen economy. New progress in the energy field in the 21st century

    International Nuclear Information System (INIS)

    Zang Mingchang

    2004-01-01

    The concept of hydrogen economy was initiated by the United States and other developed countries in the turn of the century to mitigate anxiety of national security due to growing dependence on foreign sources of energy and impacts on air quality and the potential effects of greenhouse gas emissions. Hydrogen economy integrates the primary energy used to produce hydrogen as a future energy carrier, hydrogen technologies including production, delivery and storage, and various fuel cells for transportation and stationary applications. A new hydrogen-based energy system would created as an important solution in the 21st century, flexible, affordable, safe, domestically produced, used in all sectors of the economy and in all regions of the country, if all the R and D plans and the demonstration come to be successful in 20-30 years. Among options of primary energy. Generation IV nuclear energy under development is particularly well suited to hydrogen production, offering the competitive position of large-scale hydrogen production with near-zero emissions. (author)

  4. An appealing photo-powered multi-functional energy system for the poly-generation of hydrogen and electricity

    Science.gov (United States)

    Tang, Tiantian; Li, Kan; Shen, Zhemin; Sun, Tonghua; Wang, Yalin; Jia, Jinping

    2015-10-01

    This paper focuses on a photo-powered poly-generation system (PPS) that is powered by the photocatalytic oxidation of organic substrate to produce hydrogen energy and electrical energy synchronously. This particular device runs entirely on light energy and chemical energy of substrate without external voltage. The performance measurements and optimization experiments are all investigated by using the low concentration of pure ethanol (EtOH) solution. Compared with the conventional submerged reactor for the photogeneration of hydrogen, the hydrogen and the electric current obtained in the constructed PPS are all relatively stable in experimental period and the numerical values detected are many times higher than that of the former by using various simulated ethanol waste liquid. When using Chinese rice wine as substrate at the same ethanol content level (i.e., 0.1 mol L-1), the production of hydrogen is close to that of the pure ethanol solution in the constructed PPS, but no hydrogen is detected in the conventional submerged reactor. These results demonstrate that the constructed PPS could effectively utilize light energy and perform good capability in poly-generation of hydrogen and electricity.

  5. A design-phase PSA of a nuclear-powered hydrogen plant

    International Nuclear Information System (INIS)

    Nelson, Pamela F.; Flores, Alain; Francois, Juan Luis

    2007-01-01

    A probabilistic safety assessment (PSA) is being developed for a steam-methane reforming hydrogen production plant linked to a high-temperature gas-cooled nuclear reactor (HTGR). This work is based on the Japan Atomic Energy Research Institute's (JAERI) High Temperature Engineering Test Reactor (HTTR) prototype in Japan. The objective of this paper is to show how the PSA can be used for improving the design of the coupled plants. A simplified HAZOP study was performed to identify initiating events, based on existing studies. The results of the PSA show that the average frequency of an accident at this complex that could affect the population is 7 x 10 -8 year -1 which is divided into the various end states. The dominant sequences are those that result in a methane explosion and occur with a frequency of 6.5 x 10 -8 year -1 , while the other sequences are much less frequent. The health risk presents itself if there are people in the vicinity who could be affected by the explosion. This analysis also demonstrates that an accident in one of the plants has little effect on the other. This is true given the design base distance between the plants, the fact that the reactor is underground, as well as other safety characteristics of the HTGR

  6. Hydrogen generation from formic acid catalyzed by a metal complex under amine-free and aqueous conditions

    KAUST Repository

    Huang, Kuo-Wei

    2018-01-04

    The present invention provides a class of catalyst compounds that can safely and effectively release hydrogen gas from a chemical substrate without producing either noxious byproducts or byproducts that will deactivate the catalyst. The present invention provides catalysts used to produce hydrogen that has a satisfactory and sufficient lifespan (measured by turnover number (TON)), that has stability in the presence of moisture, air, acid, or impurities, promote a rapid reaction rate, and remain stable under the reaction conditions required for an effective hydrogen production system. Described herein are compounds for use as catalysts, as well as methods for producing hydrogen from formic acid and/or a formate using the disclosed catalysts. The methods include contacting formic acid and/or a formate with a catalyst as described herein, as well as methods of producing formic acid and/or a formate using the disclosed catalyst and methods for generating electricity using the catalysts described herein.

  7. Steam generator tube degradation at the Doel 4 plant influence on plant operation and safety

    International Nuclear Information System (INIS)

    Scheveneels, G.

    1997-01-01

    The steam generator tubes of Doel 4 are affected by a multitude of corrosion phenomena. Some of them have been very difficult to manage because of their extremely fast evolution, non linear evolution behavior or difficult detectability and/or measurability. The exceptional corrosion behavior of the steam generator tubes has had its drawbacks on plant operation and safety. Extensive inspection and repair campaigns have been necessary and have largely increased outage times and radiation exposure to personnel. Although considerable effort was invested by the utility to control corrosion problems, non anticipated phenomena and/or evolution have jeopardized plant safety. The extensive plugging and repairs performed on the steam generators ha