Effect of KOH concentration on LEO cycle life of IPV nickel-hydrogen flight cell - Update II

Science.gov (United States)

Smithrick, John J.; Hall, Stephen W.

1992-01-01

An update of validation test results confirming the breakthrough in LEO cycle life of nickel-hydrogen cells containing 26 percent KOH electrolyte is presented. A breakthrough in the LEO cycle life of individual pressure vessel (IPV) nickel-hydrogen cells has been previously reported. The cycle life of boiler plate cells containing 26 percent potassium hydroxide (KOH) electrolyte was about 40,000 LEO cycles, compared to 3500 cycles for cells containing 31 percent KOH. The cycle regime was a stressful accelerated LEO, which consisted of a 27.5 min charge followed by a 17.5 min discharge (2X normal rate). The depth-of-discharge was 80 percent. Six 48-Ah Hughes recirculation design IPV nickel-hydrogen flight battery cells are being evaluated. Three of the cells contain 26 percent KOH (test cells), and three contain 31 percent KOH (control cells). They are undergoing real time LEO cycle life testing. The cycle regime is a 90-min LEO orbit consisting of a 54-min charge followed by a 36-min discharge. The depth-of-discharge is 80 percent. The cell temperature is maintained at 10 C. The three 31 percent KOH cells failed (cycles 3729, 4165, and 11355). One of the 26 percent KOH cells failed at cycle 15314. The other two 26 percent KOH cells were cycled for over 16,000 cycles during the continuing test.

Application of solar concentrators for combined production of hydrogen and electrical energy

International Nuclear Information System (INIS)

Kotevski, Darko

2008-01-01

New specific concept is application of solar dish concentrators in a process which allows solar energy to be used for splitting water in hydrogen and oxygen, with electrical energy as a byproduct. This is performed in two stages: The first stage uses highly concentrated solar energy to split CO 2 Into CO and O 2 . The second stage uses water-gas shifts reaction to cause the CO to react with water and produced hydrogen and CO 2 , Carbon dioxide is then recycled back into the system, and the waste heat is used to produce electricity in a steam turbine, Efficiency of the process is 45% , totaling 20% in chemical energy (H 2 ), and 25% electricity. This solar system is 80% more efficient than other solar technologies which make energy much cheaper. The environmentally friendly and low cost hydrogen can become a prime mover of fuel cell development especially in automotive application. (Author)

Estimation of the hydrogen concentration in rat tissue using an airtight tube following the administration of hydrogen via various routes.

Science.gov (United States)

Liu, Chi; Kurokawa, Ryosuke; Fujino, Masayuki; Hirano, Shinichi; Sato, Bunpei; Li, Xiao-Kang

2014-06-30

Hydrogen exerts beneficial effects in disease animal models of ischemia-reperfusion injury as well as inflammatory and neurological disease. Additionally, molecular hydrogen is useful for various novel medical and therapeutic applications in the clinical setting. In the present study, the hydrogen concentration in rat blood and tissue was estimated. Wistar rats were orally administered hydrogen super-rich water (HSRW), intraperitoneal and intravenous administration of hydrogen super-rich saline (HSRS), and inhalation of hydrogen gas. A new method for determining the hydrogen concentration was then applied using high-quality sensor gas chromatography, after which the specimen was prepared via tissue homogenization in airtight tubes. This method allowed for the sensitive and stable determination of the hydrogen concentration. The hydrogen concentration reached a peak at 5 minutes after oral and intraperitoneal administration, compared to 1 minute after intravenous administration. Following inhalation of hydrogen gas, the hydrogen concentration was found to be significantly increased at 30 minutes and maintained the same level thereafter. These results demonstrate that accurately determining the hydrogen concentration in rat blood and organ tissue is very useful and important for the application of various novel medical and therapeutic therapies using molecular hydrogen.

Estimation of the hydrogen concentration in rat tissue using an airtight tube following the administration of hydrogen via various routes

Science.gov (United States)

Liu, Chi; Kurokawa, Ryosuke; Fujino, Masayuki; Hirano, Shinichi; Sato, Bunpei; Li, Xiao-Kang

2014-01-01

Hydrogen exerts beneficial effects in disease animal models of ischemia-reperfusion injury as well as inflammatory and neurological disease. Additionally, molecular hydrogen is useful for various novel medical and therapeutic applications in the clinical setting. In the present study, the hydrogen concentration in rat blood and tissue was estimated. Wistar rats were orally administered hydrogen super-rich water (HSRW), intraperitoneal and intravenous administration of hydrogen super-rich saline (HSRS), and inhalation of hydrogen gas. A new method for determining the hydrogen concentration was then applied using high-quality sensor gas chromatography, after which the specimen was prepared via tissue homogenization in airtight tubes. This method allowed for the sensitive and stable determination of the hydrogen concentration. The hydrogen concentration reached a peak at 5 minutes after oral and intraperitoneal administration, compared to 1 minute after intravenous administration. Following inhalation of hydrogen gas, the hydrogen concentration was found to be significantly increased at 30 minutes and maintained the same level thereafter. These results demonstrate that accurately determining the hydrogen concentration in rat blood and organ tissue is very useful and important for the application of various novel medical and therapeutic therapies using molecular hydrogen. PMID:24975958

Hydrogen and fuel cells

International Nuclear Information System (INIS)

2006-06-01

This road-map proposes by the Group Total aims to inform the public on the hydrogen and fuel cells. It presents the hydrogen technology from the production to the distribution and storage, the issues as motor fuel and fuel cells, the challenge for vehicles applications and the Total commitments in the domain. (A.L.B.)

Theoretical and Experimental Flow Cell Studies of a Hydrogen-Bromine Fuel Cell, Part 1. M.S. Thesis. Final Report

Science.gov (United States)

Savinell, R. F.; Fritts, S. D.

1986-01-01

There is increasing interest in hydrogen-bromine fuel cells as both primary and regenerative energy storage systems. One promising design for a hydrogen-bromine fuel cell is a negative half cell having only a gas phase, which is separated by a cationic exchange membrane from a positive half cell having an aqueous electrolyte. The hydrogen gas and the aqueous bromide solution are stored external to the cell. In order to calculate the energy storage capacity and to predict and assess the performance of a single cell, the open circuit potential (OCV) must be estimated for different states of change, under various conditions. Theoretical expressions were derived to estimate the OCV of a hydrogen-bromine fuel cell. In these expressions temperature, hydrogen pressure, and bromine and hydrobromic acid concentrations were taken into consideration. Also included are the effects of the Nafion membrance separator and the various bromide complex species. Activity coefficients were taken into account in one of the expressions. The sensitivity of these parameters on the calculated OCV was studied.

Hydrogen fueling stations in Japan hydrogen and fuel cell demonstration project

International Nuclear Information System (INIS)

Koseki, K.; Tomuro, J.; Sato, H.; Maruyama, S.

2004-01-01

A new national demonstration project of fuel cell vehicles, which is called Japan Hydrogen and Fuel Cell Demonstration Project (JHFC Project), has started in FY2002 on a four-year plan. In this new project, ten hydrogen fueling stations have been constructed in Tokyo and Kanagawa area in FY2002-2003. The ten stations adopt the following different types of fuel and fueling methods: LPG reforming, methanol reforming, naphtha reforming, desulfurized-gasoline reforming, kerosene reforming, natural gas reforming, water electrolysis, liquid hydrogen, by-product hydrogen, and commercially available cylinder hydrogen. Approximately fifty fuel cell passenger cars and a fuel cell bus are running on public roads using these stations. In addition, two hydrogen stations will be constructed in FY2004 in Aichi prefecture where The 2005 World Exposition (EXPO 2005) will be held. The stations will service eight fuel cell buses used as pick-up buses for visitors. We, Engineering Advancement Association of Japan (ENAA), are commissioned to construct and operate a total of twelve stations by Ministry of Economy Trade and Industry (METI). We are executing to demonstrate or identify the energy-saving effect, reduction of the environmental footprint, and issues for facilitating the acceptance of hydrogen stations on the basis of the data obtained from the operation of the stations. (author)

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.

Hydrogen storage and integrated fuel cell assembly

Science.gov (United States)

Gross, Karl J.

2010-08-24

Hydrogen is stored in materials that absorb and desorb hydrogen with temperature dependent rates. A housing is provided that allows for the storage of one or more types of hydrogen-storage materials in close thermal proximity to a fuel cell stack. This arrangement, which includes alternating fuel cell stack and hydrogen-storage units, allows for close thermal matching of the hydrogen storage material and the fuel cell stack. Also, the present invention allows for tailoring of the hydrogen delivery by mixing different materials in one unit. Thermal insulation alternatively allows for a highly efficient unit. Individual power modules including one fuel cell stack surrounded by a pair of hydrogen-storage units allows for distribution of power throughout a vehicle or other electric power consuming devices.

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

Adsorption process to recover hydrogen from feed gas mixtures having low hydrogen concentration

Science.gov (United States)

Golden, Timothy Christopher; Weist, Jr., Edward Landis; Hufton, Jeffrey Raymond; Novosat, Paul Anthony

2010-04-13

A process for selectively separating hydrogen from at least one more strongly adsorbable component in a plurality of adsorption beds to produce a hydrogen-rich product gas from a low hydrogen concentration feed with a high recovery rate. Each of the plurality of adsorption beds subjected to a repetitive cycle. The process comprises an adsorption step for producing the hydrogen-rich product from a feed gas mixture comprising 5% to 50% hydrogen, at least two pressure equalization by void space gas withdrawal steps, a provide purge step resulting in a first pressure decrease, a blowdown step resulting in a second pressure decrease, a purge step, at least two pressure equalization by void space gas introduction steps, and a repressurization step. The second pressure decrease is at least 2 times greater than the first pressure decrease.

Estimating changes in urban ozone concentrations due to life cycle emissions from hydrogen transportation systems

Science.gov (United States)

Wang, Guihua; Ogden, Joan M.; Chang, Daniel P. Y.

Hydrogen has been proposed as a low polluting alternative transportation fuel that could help improve urban air quality. This paper examines the potential impact of introducing a hydrogen-based transportation system on urban ambient ozone concentrations. This paper considers two scenarios, where significant numbers of new hydrogen vehicles are added to a constant number of gasoline vehicles. In our scenarios hydrogen fuel cell vehicles (HFCVs) are introduced in Sacramento, California at market penetrations of 9% and 20%. From a life cycle analysis (LCA) perspective, considering all the emissions involved in producing, transporting, and using hydrogen, this research compares three hypothetical natural gas to hydrogen pathways: (1) on-site hydrogen production; (2) central hydrogen production with pipeline delivery; and (3) central hydrogen production with liquid hydrogen truck delivery. Using a regression model, this research shows that the daily maximum temperature correlates well with atmospheric ozone formation. However, increases in initial VOC and NO x concentrations do not necessarily increase the peak ozone concentration, and may even cause it to decrease. It is found that ozone formation is generally limited by NO x in the summer and is mostly limited by VOC in the fall in Sacramento. Of the three hydrogen pathways, the truck delivery pathway contributes the most to ozone precursor emissions. Ozone precursor emissions from the truck pathway at 9% market penetration can cause additional 3-h average VOC (or NO x) concentrations up to approximately 0.05% (or 1%) of current pollution levels, and at 20% market penetration up to approximately 0.1% (or 2%) of current pollution levels. However, all of the hydrogen pathways would result in very small (either negative or positive) changes in ozone air quality. In some cases they will result in worse ozone air quality (mostly in July, August, and September), and in some cases they will result in better ozone air quality

Estimating changes in urban ozone concentrations due to life cycle emissions from hydrogen transportation systems

International Nuclear Information System (INIS)

Guihua Wang; Ogden, Joan M.; Chang, Daniel P.Y.

2007-01-01

Hydrogen has been proposed as a low polluting alternative transportation fuel that could help improve urban air quality. This paper examines the potential impact of introducing a hydrogen-based transportation system on urban ambient ozone concentrations. This paper considers two scenarios, where significant numbers of new hydrogen vehicles are added to a constant number of gasoline vehicles. In our scenarios hydrogen fuel cell vehicles (HFCVs) are introduced in Sacramento, California at market penetrations of 9% and 20%. From a life cycle analysis (LCA) perspective, considering all the emissions involved in producing, transporting, and using hydrogen, this research compares three hypothetical natural gas to hydrogen pathways: (1) on-site hydrogen production; (2) central hydrogen production with pipeline delivery; and (3) central hydrogen production with liquid hydrogen truck delivery. Using a regression model, this research shows that the daily maximum temperature correlates well with atmospheric ozone formation. However, increases in initial VOC and NO x concentrations do not necessarily increase the peak ozone concentration, and may even cause it to decrease. It is found that ozone formation is generally limited by NO x in the summer and is mostly limited by VOC in the fall in Sacramento. Of the three hydrogen pathways, the truck delivery pathway contributes the most to ozone precursor emissions. Ozone precursor emissions from the truck pathway at 9% market penetration can cause additional 3-h average VOC (or NO x ) concentrations up to approximately 0.05% (or 1%) of current pollution levels, and at 20% market penetration up to approximately 0.1% (or 2%) of current pollution levels. However, all of the hydrogen pathways would result in very small (either negative or positive) changes in ozone air quality. In some cases they will result in worse ozone air quality (mostly in July, August, and September), and in some cases they will result in better ozone air

Effect of the hydrogen concentration on the ductility of Zry-4

International Nuclear Information System (INIS)

Domizzi, G.; Ovejero Garcia, J.

1996-01-01

After many years in service, zirconium alloys employed in nuclear reactors may reach high contents of hydride particles, exceeding the hydrogen solid solubility at the service temperature. The brittle character of zirconium hydride promotes the alloy embrittlement. In order to predict the critical hydrogen concentration which causes a ductile-brittle transition in a Zry-4 foil, 0.02mm thick, tensile test specimens were hydride by gaseous charging. To obtain uniform hydride distribution the specimens were electroplated with a film of copper prior to gaseous charge. In absence of oxide film, the foils retained its ductility up to high hydrogen concentration (950 Og/g). The critical hydrogen concentration was attained at 2900-3100 Og/g. (author). 4 refs., 2 figs., 1 tab

Process for hydrogen isotope exchange and concentration between liquid water and hydrogen gas and catalyst assembly therefor

International Nuclear Information System (INIS)

Stevens, W.H.

1975-01-01

A bithermal, catalytic, hydrogen isotope exchange process between liquid water and hydrogen gas to effect concentration of the deuterium isotope of hydrogen is described. Liquid water and hydrogen gas are contacted with one another and with at least one catalytically active metal selected from Group VIII of the Periodic Table; the catalyst body has a water repellent, gas and water vapor permeable, organic polymer or resin coating, preferably a fluorinated olefin polymer or silicone resin coating, so that the isotope exchange takes place by two simultaneously occurring, and closely coupled in space, steps and concentration is effected by operating two interconnected sections containing catalyst at different temperatures. (U.S.)

Hydrogen-bromine fuel cell advance component development

Science.gov (United States)

Charleston, Joann; Reed, James

1988-01-01

Advanced cell component development is performed by NASA Lewis to achieve improved performance and longer life for the hydrogen-bromine fuel cells system. The state-of-the-art hydrogen-bromine system utilizes the solid polymer electrolyte (SPE) technology, similar to the SPE technology developed for the hydrogen-oxygen fuel cell system. These studies are directed at exploring the potential for this system by assessing and evaluating various types of materials for cell parts and electrode materials for Bromine-hydrogen bromine environment and fabricating experimental membrane/electrode-catalysts by chemical deposition.

Determination of diffusible and total hydrogen concentration in coated and uncoated steel

Energy Technology Data Exchange (ETDEWEB)

Mabho, Nonhlangabezo

2010-09-23

The new trend in the steel industry demands thin, flexible, high strength steels with low internal embrittlement. It is a well known fact that the atomic hydrogen which is picked up during production, fabrication and service embrittles the steel. This has led to an extensive research towards the improvement of the quality of metallic materials by focusing on total and diffusible hydrogen concentrations which are responsible for hydrogen embrittlement. Since the internal embrittlement cannot be foreseen, the concentrations of diffusible hydrogen work as indicators while the total hydrogen characterizes the absorbed quantities and quality of that particular product. To meet these requirements, the analytical chemistry methods which include the already existing carrier gas melt (fusion) extraction methods that use infrared and thermal conductivity for total hydrogen detection were applied. The newly constructed carrier gas thermal desorption mass spectroscopy was applied to monitor the diffusible concentration at specific temperatures and desorption rates of hydrogen which will contribute towards the quality of materials during service. The TDMS method also involved the characterization of the energy quantity (activation energy) required by hydrogen to be removed from traps of which irreversible traps are preferred because they enhance the stability of the product by inhibiting the mobility of hydrogen which is detrimental to the metallic structures. The instrumentation for TDMS is quite simple, compact, costs less and applicable to routine analysis. To determine total and diffusible hydrogen, the influence of the following processes: chemical and mechanical zinc coating removal, sample cleaning with organic solvents, conditions for hydrogen absorption by electrolytic hydrogen charging, conditions of hydrogen desorption by storing the sample at room temperature, solid CO{sub 2} and at temperatures of the drier was analysed. The contribution of steel alloys towards

Water reactive hydrogen fuel cell power system

Science.gov (United States)

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

2014-01-21

A water reactive hydrogen fueled power system includes devices and methods to combine reactant fuel materials and aqueous solutions to generate hydrogen. The generated hydrogen is converted in a fuel cell to provide electricity. The water reactive hydrogen fueled power system includes a fuel cell, a water feed tray, and a fuel cartridge to generate power for portable power electronics. The removable fuel cartridge is encompassed by the water feed tray and fuel cell. The water feed tray is refillable with water by a user. The water is then transferred from the water feed tray into a fuel cartridge to generate hydrogen for the fuel cell which then produces power for the user.

HYDROGEN PRODUCTION BY THE CYANOBACTERIUM PLECTONEMA BORYANUM: EFFECTS OF INITIAL NITRATE CONCENTRATION, LIGHT INTENSITY, AND INHIBITION OF PHOTOSYSTEM II BY DCMU

Energy Technology Data Exchange (ETDEWEB)

Carter, B.; Huesemann, M.

2008-01-01

The alarming rate at which atmospheric carbon dioxide levels are increasing due to the burning of fossil fuels will have incalculable consequences if disregarded. Fuel cells, a source of energy that does not add to carbon dioxide emissions, have become an important topic of study. Although signifi cant advances have been made related to fuel cells, the problem of cheap and renewable hydrogen production still remains. The cyanobacterium Plectonema boryanum has demonstrated potential as a resolution to this problem by producing hydrogen under nitrogen defi cient growing conditions. Plectonema boryanum cultures were tested in a series of experiments to determine the effects of light intensity, initial nitrate concentration, and photosystem II inhibitor DCMU (3-(3,4- dichlorophenyl)-1,1-dimethylurea) upon hydrogen production. Cultures were grown in sterile Chu. No. 10 medium within photobioreactors constantly illuminated by halogen lights. Because the enzyme responsible for hydrogen production is sensitive to oxygen, the medium was continuously sparged with argon/CO2 (99.7%/0.3% vol/vol) by gas dispersion tubes immersed in the culture. Hydrogen production was monitored by using a gas chromatograph equipped with a thermal conductivity detector. In the initial experiment, the effects of initial nitrate concentration were tested and results revealed cumulative hydrogen production was maximum at an initial nitrate concentration of 1 mM. A second experiment was then conducted at an initial nitrate concentration of 1 mM to determine the effects of light intensity at 50, 100, and 200 μmole m-2 s-1. Cumulative hydrogen production increased with increasing light intensity. A fi nal experiment, conducted at an initial nitrate concentration of 2 mM, tested the effects of high light intensity at 200 and 400 μmole m-2 s-1. Excessive light at 400 μmole m-2 s-1 decreased cumulative hydrogen production. Based upon all experiments, cumulative hydrogen production rates were optimal

Optimization of catholyte concentration and anolyte pHs in two chamber microbial electrolysis cells

KAUST Repository

Nam, Joo-Youn; Logan, Bruce E.

2012-01-01

The hydrogen production rate in a microbial electrolysis cell (MEC) using a non-buffered saline catholyte (NaCl) can be optimized through proper control of the initial anolyte pH and catholyte NaCl concentration. The highest hydrogen yield of 3

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.

Hydrogen Fuel Cell Vehicles

OpenAIRE

Anton Francesch, Judit

1992-01-01

Hydrogen is an especially attractive transportation fuel. It is the least polluting fuel available, and can be produced anywhere there is water and a clean source of electricity. A fuel cycle in which hydrogen is produced by solar-electrolysis of water, or by gasification of renewably grown biomass, and then used in a fuel-cell powered electric-motor vehicle (FCEV), would produce little or no local, regional, or global pollution. Hydrogen FCEVs would combine the best features of bat...

Demystifying the hydrogen and fuel cell industry: Where are the investment opportunities in B.C.?

Energy Technology Data Exchange (ETDEWEB)

Kettlewell, D. [Hydrogen Media, BC (Canada)

2004-07-01

It is forecast that accessible supplies of oil will decline by 2020; a similar fate is forecast for natural gas occurring 20 years later in 2040. Taking into account finite supply sources and environmental concerns, planners are forced to consider alternative energy sources. In considering energy alternatives, hydrogen is commonly identified as the potential energy elixir, given its ability to generate highly concentrated forms of energy with clean water being the only 'waste product'. British Columbia has been the locus of major hydrogen and fuel cell research in Canada and is, therefore, in an exceptionally good position to play a leading role in the development of this abundant and clean energy source. This paper examines the history and future investments in BC's hydrogen and fuel cell sectors from a macro financial point of view, and with a critical eye towards global developments. The report recommends development of a Hydrogen Energy Research Centre of Excellence in BC; increased collaboration between private firms, academic researchers and technology partners; development of quantifiable and measurable revenue goals for the fuel cell sector; and additional tax benefit policies to attract and retain hydrogen specialists and entrepreneurs in BC. With regard to investments specifically, the report recommends building appropriate industry and academic relationships; concentration of clients, partners and revenues in geographic clusters closer to home before expanding around the world; development of local media interest in the sector; increased public awareness; focus on standards and opportunities for 'angel' investors; and creating increased awareness of the most promising areas of the industry for venture capital to focus on. Based on the high concentration of fuel cell intellectual capital in BC, the report forecasts substantial growth in BC's hydrogen economy in 2006 and beyond.

Hydrogen utilization efficiency in PEM fuel cells

Energy Technology Data Exchange (ETDEWEB)

Metkemeyer, R; Achard, P; Rouveyre, L; Picot, D [Ecole des Mines de Paris, Centre D' energrtique, Sophia Antipolis (France)

1998-07-01

In this paper, we present the work carried out within the framework of the FEVER project (Fuel cell Electric Vehicle for Efficiency and Range), an European project coordinated by Renault, joining Ecole des Mines de Paris, Ansaldo, De Nora, Air Liquide and Volvo. For the FEVER project, where an electrical air compressor is used for oxidant supply, there is no need for hydrogen spill over, meaning that the hydrogen stoichiometry has to be as close to one as possible. To determine the optimum hydrogen utilization efficiency for a 10 kW Proton Exchange Membrane Fuel Cell (PEMFC) fed with pure hydrogen, a 4 kW prototype fuel cell was tested with and without a hydrogen recirculator at the test facility of Ecole des Mines de Paris. Nitrogen cross over from the cathodic compartment to the anodic compartment limits the hydrogen utilization of the fuel cell without recirculator to 97.4 % whereas 100% is feasible when a recirculator is used. 5 refs.

Photoelectrochemical water splitting in separate oxygen and hydrogen cells

Science.gov (United States)

Landman, Avigail; Dotan, Hen; Shter, Gennady E.; Wullenkord, Michael; Houaijia, Anis; Maljusch, Artjom; Grader, Gideon S.; Rothschild, Avner

2017-06-01

Solar water splitting provides a promising path for sustainable hydrogen production and solar energy storage. One of the greatest challenges towards large-scale utilization of this technology is reducing the hydrogen production cost. The conventional electrolyser architecture, where hydrogen and oxygen are co-produced in the same cell, gives rise to critical challenges in photoelectrochemical water splitting cells that directly convert solar energy and water to hydrogen. Here we overcome these challenges by separating the hydrogen and oxygen cells. The ion exchange in our cells is mediated by auxiliary electrodes, and the cells are connected to each other only by metal wires, enabling centralized hydrogen production. We demonstrate hydrogen generation in separate cells with solar-to-hydrogen conversion efficiency of 7.5%, which can readily surpass 10% using standard commercial components. A basic cost comparison shows that our approach is competitive with conventional photoelectrochemical systems, enabling safe and potentially affordable solar hydrogen production.

Hydrogen fuel cell engines and related technologies

Science.gov (United States)

2001-12-01

The manual documents the first training course developed on the use of hydrogen fuel cells in transportation. The manual contains eleven modules covering hydrogen properties, use and safety; fuel cell technology and its systems, fuel cell engine desi...

Microbial electrolysis cells as innovative technology for hydrogen production

International Nuclear Information System (INIS)

Chorbadzhiyska, Elitsa; Hristov, Georgi; Mitov, Mario; Hubenova, Yolina

2011-01-01

Hydrogen production is becoming increasingly important in view of using hydrogen in fuel cells. However, most of the production of hydrogen so far comes from the combustion of fossil fuels and water electrolysis. Microbial Electrolysis Cell (MEC), also known as Bioelectrochemically Assisted Microbial Reactor, is an ecologically clean, renewable and innovative technology for hydrogen production. Microbial electrolysis cells produce hydrogen mainly from waste biomass assisted by various bacteria strains. The principle of MECs and their constructional elements are reviewed and discussed. Keywords: microbial Electrolysis Cells, hydrogen production, waste biomass purification

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

Suspension Hydrogen Reduction of Iron Oxide Concentrates

Energy Technology Data Exchange (ETDEWEB)

H.Y. Sohn

2008-03-31

The objective of the project is to develop a new ironmaking technology based on hydrogen and fine iron oxide concentrates in a suspension reduction process. The ultimate objective of the new technology is to replace the blast furnace and to drastically reduce CO2 emissions in the steel industry. The goals of this phase of development are; the performance of detailed material and energy balances, thermochemical and equilibrium calculations for sulfur and phosphorus impurities, the determination of the complete kinetics of hydrogen reduction and bench-scale testing of the suspension reduction process using a large laboratory flash reactor.

Hydrogen concentration and distribution in high-purity germanium crystals

International Nuclear Information System (INIS)

Hansen, W.L.; Haller, E.E.; Luke, P.N.

1981-10-01

High-purity germanium crystals used for making nuclear radiation detectors are usually grown in a hydrogen ambient from a melt contained in a high-purity silica crucible. The benefits and problems encountered in using a hydrogen ambient are reviewed. A hydrogen concentration of about 2 x 10 15 cm -3 has been determined by growing crystals in hydrogen spiked with tritium and counting the tritium β-decays in detectors made from these crystals. Annealing studies show that the hydrogen is strongly bound, either to defects or as H 2 with a dissociation energy > 3 eV. This is lowered to 1.8 eV when copper is present. Etching defects in dislocation-free crystals grown in hydrogen have been found by etch stripping to have a density of about 1 x 10 7 cm -3 and are estimated to contain 10 8 H atoms each

Anti-tumor Effects of Plasma Activated Media and Correlation with Hydrogen Peroxide Concentration

Science.gov (United States)

Laroussi, Mounir; Mohades, Soheila; Barekzi, Nazir; Maruthamuthu, Venkat; Razavi, Hamid

2016-09-01

Plasma activated media (PAM) can induce death in cancer cells. In our research, PAM is produced by exposing liquid culture medium to a helium plasma pencil. Reactive oxygen and nitrogen species in the aqueous state are known factors in anti-tumor effects of PAM. The duration of plasma exposure determines the concentrations of reactive species produced in PAM. Stability of the plasma generated reactive species and their lifetime depend on parameters such as the chemical composition of the medium. Here, a complete cell culture medium was employed to make PAM. Later, PAM was used to treat SCaBER cancer cells either as an immediate PAM (right after exposure) or as an aged-PAM (after storage). SCaBER (ATCC®HTB-3™) is an epithelial cell line from a human bladder with the squamous carcinoma disease. A normal epithelial cell line from a kidney tissue of a dog - MDCK (ATCC®CCL-34™) - was used to analyze the selective effect of PAM. Correspondingly, we measured the concentration of hydrogen peroxide- as a stable species with biological impact on cell viability- in both immediate PAM and aged-PAM. In addition, we report on the effect of serum supplemented in PAM on the H2O2 concentration measured by Amplex red assay kit. Finally, we evaluate the effects of PAM on growth and morphological changes in MDCK cells using fluorescence microscopy.

Optimization of catholyte concentration and anolyte pHs in two chamber microbial electrolysis cells

KAUST Repository

Nam, Joo-Youn

2012-12-01

The hydrogen production rate in a microbial electrolysis cell (MEC) using a non-buffered saline catholyte (NaCl) can be optimized through proper control of the initial anolyte pH and catholyte NaCl concentration. The highest hydrogen yield of 3.3 ± 0.4 mol H2/mole acetate and gas production rate of 2.2 ± 0.2 m3 H2/m3/d were achieved here with an initial anolyte pH = 9 and catholyte NaCl concentration of 98 mM. Further increases in the salt concentration substantially reduced the anolyte pH to as low as 4.6, resulting in reduced MEC performance due to pH inhibition of exoelectrogens. Cathodic hydrogen recovery was high (rcat > 90%) as hydrogen consumption by hydrogenotrophic methanogens was prevented by separating the anode and cathode chambers using a membrane. These results show that the MEC can be optimized for hydrogen production through proper choices in the concentration of a non-buffered saline catholyte and initial anolyte pH in two chamber MECs. Copyright © 2012, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.

Hydrogen and oxygen concentrations in IXCs: A compilation

International Nuclear Information System (INIS)

Liljegren, L.M.; Terrones, G.T.; Melethil, P.K.

1996-06-01

This paper contains four reports and two internal letters that address the estimation of hydrogen and oxygen concentrations in ion exchange columns that treat the water of the K-East and K-West Basins at Hanford. The concern is the flammability of this mixture of gases and planning for safe transport during decommissioning. A transient will occur when the hydrogen filter is temporarily blocked by a sandbag. Analyses are provided for steady-state, transients, and for both wet and dry resins

DOE Hydrogen and Fuel Cells Program Plan (September 2011)

Energy Technology Data Exchange (ETDEWEB)

none,

2011-09-01

The Department of Energy Hydrogen and Fuel Cells Program Plan outlines the strategy, activities, and plans of the DOE Hydrogen and Fuel Cells Program, which includes hydrogen and fuel cell activities within the EERE Fuel Cell Technologies Program and the DOE offices of Nuclear Energy, Fossil Energy, and Science.

Hydrogen passivation of multi-crystalline silicon solar cells

Institute of Scientific and Technical Information of China (English)

胡志华; 廖显伯; 刘祖明; 夏朝凤; 陈庭金

2003-01-01

The effects of hydrogen passivation on multi-crystalline silicon (mc-Si) solar cells are reported in this paper.Hydrogen plasma was generated by means of ac glow discharge in a hydrogen atmosphere. Hydrogen passivation was carried out with three different groups of mc-Si solar cells after finishing contacts. The experimental results demonstrated that the photovoltaic performances of the solar cell samples have been improved after hydrogen plasma treatment, with a relative increase in conversion efficiency up to 10.6%. A calculation modelling has been performed to interpret the experimental results using the model for analysis of microelectronic and photonic structures developed at Pennsylvania State University.

Hydrogen peroxide as a sustainable energy carrier: Electrocatalytic production of hydrogen peroxide and the fuel cell

International Nuclear Information System (INIS)

Fukuzumi, Shunichi; Yamada, Yusuke; Karlin, Kenneth D.

2012-01-01

This review describes homogeneous and heterogeneous catalytic reduction of dioxygen with metal complexes focusing on the catalytic two-electron reduction of dioxygen to produce hydrogen peroxide. Whether two-electron reduction of dioxygen to produce hydrogen peroxide or four-electron O 2 -reduction to produce water occurs depends on the types of metals and ligands that are utilized. Those factors controlling the two processes are discussed in terms of metal–oxygen intermediates involved in the catalysis. Metal complexes acting as catalysts for selective two-electron reduction of oxygen can be utilized as metal complex-modified electrodes in the electrocatalytic reduction to produce hydrogen peroxide. Hydrogen peroxide thus produced can be used as a fuel in a hydrogen peroxide fuel cell. A hydrogen peroxide fuel cell can be operated with a one-compartment structure without a membrane, which is certainly more promising for the development of low-cost fuel cells as compared with two compartment hydrogen fuel cells that require membranes. Hydrogen peroxide is regarded as an environmentally benign energy carrier because it can be produced by the electrocatalytic two-electron reduction of O 2 , which is abundant in air, using solar cells; the hydrogen peroxide thus produced could then be readily stored and then used as needed to generate electricity through the use of hydrogen peroxide fuel cells.

Hydrogen Peroxide as a Sustainable Energy Carrier: Electrocatalytic Production of Hydrogen Peroxide and the Fuel Cell.

Science.gov (United States)

Fukuzumi, Shunichi; Yamada, Yusuke; Karlin, Kenneth D

2012-11-01

This review describes homogeneous and heterogeneous catalytic reduction of dioxygen with metal complexes focusing on the catalytic two-electron reduction of dioxygen to produce hydrogen peroxide. Whether two-electron reduction of dioxygen to produce hydrogen peroxide or four-electron O 2 -reduction to produce water occurs depends on the types of metals and ligands that are utilized. Those factors controlling the two processes are discussed in terms of metal-oxygen intermediates involved in the catalysis. Metal complexes acting as catalysts for selective two-electron reduction of oxygen can be utilized as metal complex-modified electrodes in the electrocatalytic reduction to produce hydrogen peroxide. Hydrogen peroxide thus produced can be used as a fuel in a hydrogen peroxide fuel cell. A hydrogen peroxide fuel cell can be operated with a one-compartment structure without a membrane, which is certainly more promising for the development of low-cost fuel cells as compared with two compartment hydrogen fuel cells that require membranes. Hydrogen peroxide is regarded as an environmentally benign energy carrier because it can be produced by the electrocatalytic two-electron reduction of O 2 , which is abundant in air, using solar cells; the hydrogen peroxide thus produced could then be readily stored and then used as needed to generate electricity through the use of hydrogen peroxide fuel cells.

Cleaning the Air and Improving Health with Hydrogen Fuel-Cell Vehicles

Science.gov (United States)

Jacobson, M. Z.; Colella, W. G.; Golden, D. M.

2005-06-01

Converting all U.S. onroad vehicles to hydrogen fuel-cell vehicles (HFCVs) may improve air quality, health, and climate significantly, whether the hydrogen is produced by steam reforming of natural gas, wind electrolysis, or coal gasification. Most benefits would result from eliminating current vehicle exhaust. Wind and natural gas HFCVs offer the greatest potential health benefits and could save 3700 to 6400 U.S. lives annually. Wind HFCVs should benefit climate most. An all-HFCV fleet would hardly affect tropospheric water vapor concentrations. Conversion to coal HFCVs may improve health but would damage climate more than fossil/electric hybrids. The real cost of hydrogen from wind electrolysis may be below that of U.S. gasoline.

Procedure for reducing hydrogen ion concentration in acidic anion eluate

International Nuclear Information System (INIS)

Parobek, P.; Baloun, S.; Plevac, S.

1992-01-01

A procedure is suggested for reducing the concentration of hydrogen ions in the acidic anionic eluate formed during the separation of uranium. The procedure involves anex elution, precipitation, filtration, precipitate rinsing, and anex rinsing. The procedure is included in the uranium elution process and requires at least one ion exchanger column and at least one tank in the continuous or discontinuous mode. Sparing the neutralizing agent by reducing the hydrogen ion concentration in the acidic anionic eluate is a major asset of this procedure. (Z.S.). 1 fig

KOH concentration effect on cycle life of nickel-hydrogen cells. III - Cycle life test

Science.gov (United States)

Lim, H. S.; Verzwyvelt, S. A.

1988-01-01

A cycle life test of Ni/H2 cells containing electrolytes of various KOH concentrations and a sintered type nickel electrode was carried out at 23 C using a 45 min accelerated low earth orbit (LEO) cycle regime at 80 percent depth of discharge. One of three cells containing 26 percent KOH has achieved over 28,000 cycles, and the other two 19,000 cycles, without a sign of failure. Two other cells containing 31 percent KOH electrolyte, which is the concentration presently used in aerospace cells, failed after 2,979 and 3,620 cycles. This result indicates that the cycle life of the present type of Ni/H2 cells may be extended by a factor of 5 to 10 simply by lowering the KOH concentration. Long cycle life of a Ni/H2 battery at high depth-of-discharge operation is desired, particularly for an LEO spacecraft application. Typically, battery life of about 30,000 cycles is required for a five year mission in an LEO. Such a cycle life with presently available cells can be assured only at a very low depth-of-discharge operation. Results of testing already show that the cycle life of an Ni/H2 cell is tremendously improved by simply using an electrolyte of low KOH concentration.

ELECTROCHEMICAL SEPARATION AND CONCENTRATION OF HYDROGEN SULFIDE FROM GAS MIXTURES

Science.gov (United States)

Winnick, Jack; Sather, Norman F.; Huang, Hann S.

1984-10-30

A method of removing sulfur oxides of H.sub.2 S from high temperature gas mixtures (150.degree.-1000.degree. C.) is the subject of the present invention. An electrochemical cell is employed. The cell is provided with inert electrodes and an electrolyte which will provide anions compatible with the sulfur containing anions formed at the anode. The electrolyte is also selected to provide inert stable cations at the temperatures encountered. The gas mixture is passed by the cathode where the sulfur gases are converted to SO.sub.4 -- or, in the case of H.sub.2 S, to S--. The anions migrate to the anode where they are converted to a stable gaseous form at much greater concentration levels (>10X). Current flow may be effected by utilizing an external source of electrical energy or by passing a reducing gas such as hydrogen past the anode.

Study on Molasses Concentration from Sugarcanne Bagasse for Biohydrogen Production using Enriched Granular Activated Carbon (GAC) Immobilised Cells by Repeated Batch Cultivation

Science.gov (United States)

Idris, Norfatiha; Aminah Lutpi, Nabilah; Ruhaizul Che Ridzuan, Che Mohd; Shian, Wong Yee; Nuraiti Tengku Izhar, Tengku

2018-03-01

Repeated batch cultivation is known as most attractive method in improving hydrogen productivity, due to the facts that this approach could minimize the reuse of the cell and the inoculum preparation. In addition, with the combination of attach growth system during the fermentation processes to produce biohydrogen, the density of cells will be increased and the cell washout could be avoided. Therefore, this study aimed to examine the effectiveness of repeated batch cultivation for enrichment of anaerobic mixed culture onto granular activated carbon (GAC) and investigate the effect of molasses concentration during immobilization of mixed culture onto the GAC. The molasses concentration using 50 %, 40 %, 30 %, 20 % and 10 % of diluted molasses were used as feedstock in the fermentation process. The maximum hydrogen production of 60 ml was obtained at 30 % of molasses concentration with 831 ppm of hydrogen concentration. Thus, the kinetic parameter obtained from the batch profiling based on modified Gompertz equation are, Hm= 58 ml for the maximum hydrogen production and Rm= 2.02 ml/h representing the hydrogen production rate.

Optimization studies of bio-hydrogen production in a coupled microbial electrolysis-dye sensitized solar cell system.

Science.gov (United States)

Ajayi, Folusho Francis; Kim, Kyoung-Yeol; Chae, Kyu-Jung; Choi, Mi-Jin; Chang, In Seop; Kim, In S

2010-03-01

Bio-hydrogen production in light-assisted microbial electrolysis cell (MEC) with a dye sensitized solar cell (DSSC) was optimized by connecting multiple MECs to a single dye (N719) sensitized solar cell (V(OC) approx. 0.7 V). Hydrogen production occurred simultaneously in all the connected MECs when the solar cell was irradiated with light. The amount of hydrogen produced in each MEC depends on the activity of the microbial catalyst on their anode. Substrate (acetate) to hydrogen conversion efficiencies ranging from 42% to 65% were obtained from the reactors during the experiment. A moderate light intensity of 430 W m(-2) was sufficient for hydrogen production in the coupled MEC-DSSC. A higher light intensity of 915 W m(-2), as well as an increase in substrate concentration, did not show any improvement in the current density due to limitation caused by the rate of microbial oxidation on the anode. A significant reduction in the surface area of the connected DSSC only showed a slight effect on current density in the coupled MEC-DSSC system when irradiated with light.

Hydrogen peroxide stimulates cell motile activity through LPA receptor-3 in liver epithelial WB-F344 cells

Energy Technology Data Exchange (ETDEWEB)

Shibata, Ayano; Tanabe, Eriko; Inoue, Serina; Kitayoshi, Misaho; Okimoto, Souta; Hirane, Miku; Araki, Mutsumi [Division of Cancer Biology and Bioinformatics, Department of Life Science, Faculty of Science and Engineering, Kinki University, 3-4-1, Kowakae, Higashiosaka, Osaka 577-8502 (Japan); Fukushima, Nobuyuki [Division of Molecular Neurobiology, Department of Life Science, Faculty of Science and Engineering, Kinki University, 3-4-1, Kowakae, Higashiosaka, Osaka 577-8502 (Japan); Tsujiuchi, Toshifumi, E-mail: ttujiuch@life.kindai.ac.jp [Division of Cancer Biology and Bioinformatics, Department of Life Science, Faculty of Science and Engineering, Kinki University, 3-4-1, Kowakae, Higashiosaka, Osaka 577-8502 (Japan)

2013-04-12

Highlights: •Hydrogen peroxide stimulates cell motility of WB-F344 cells. •LPA{sub 3} is induced by hydrogen peroxide in WB-F344 cells. •Cell motility by hydrogen peroxide is inhibited in LPA{sub 3} knockdown cells. •LPA signaling is involved in cell migration by hydrogen peroxide. -- Abstract: Hydrogen peroxide which is one of reactive oxygen species (ROS) mediates a variety of biological responses, including cell proliferation and migration. In the present study, we investigated whether lysophosphatidic acid (LPA) signaling is involved in cell motile activity stimulated by hydrogen peroxide. The rat liver epithelial WB-F344 cells were treated with hydrogen peroxide at 0.1 or 1 μM for 48 h. In cell motility assays, hydrogen peroxide treated cells showed significantly high cell motile activity, compared with untreated cells. To measure the expression levels of LPA receptor genes, quantitative real time RT-PCR analysis was performed. The expressions of LPA receptor-3 (Lpar3) in hydrogen peroxide treated cells were significantly higher than those in control cells, but not Lpar1 and Lpar2 genes. Next, to assess the effect of LPA{sub 3} on cell motile activity, the Lpar3 knockdown cells from WB-F344 cells were also treated with hydrogen peroxide. The cell motile activity of the knockdown cells was not stimulated by hydrogen peroxide. Moreover, in liver cancer cells, hydrogen peroxide significantly activated cell motility of Lpar3-expressing cells, but not Lpar3-unexpressing cells. These results suggest that LPA signaling via LPA{sub 3} may be mainly involved in cell motile activity of WB-F344 cells stimulated by hydrogen peroxide.

Hydrogen passivation of polycrystalline Si thin film solar cells

International Nuclear Information System (INIS)

Gorka, Benjamin

2010-01-01

Hydrogen passivation is a key process step in the fabrication of polycrystalline Si (poly-Si) thin film solar cells. In this work a parallel plate rf plasma setup was used for the hydrogen passivation treatment. The main topics that have been investigated are (i) the role of plasma parameters (like hydrogen pressure, electrode gap and plasma power), (ii) the dynamics of the hydrogen treatment and (iii) passivation of poly-Si with different material properties. Passivation was characterized by measuring the open-circuit voltage V OC of poly-Si reference samples. Optimum passivation conditions were found by measurements of the breakdown voltage V brk of the plasma for different pressures p and electrode gaps d. For each pressure, the best passivation was achieved at a gap d that corresponded to the minimum in V brk . Plasma simulations were carried out, which indicate that best V OC corresponds to a minimum in ion energy. V OC was not improved by a larger H flux. Investigations of the passivation dynamic showed that a plasma treatment in the lower temperature range (≤400 C) is slow and takes several hours for the V OC to saturate. Fast passivation can be successfully achieved at elevated temperatures around 500 C to 600 C with a plateau time of 10 min. It was found that prolonged hydrogenation leads to a loss in V OC , which is less pronounced within the observed optimum temperature range (500 C-600 C). Electron beam evaporation has been investigated as an alternative method to fabricate poly-Si absorbers. The material properties have been tuned by alteration of substrate temperature T dep =200-700 C and were characterized by Raman, ESR and V OC measurements. Largest grains were obtained after solid phase crystallization (SPC) of a-Si, deposited in the temperature range of 300 C. The defect concentration of Si dangling bonds was lowered by passivation by about one order of magnitude. The lowest dangling bond concentration of 2.5.10 16 cm -3 after passivation was

Hydrogen Passivation of N(+)P and P(+)N Heteroepitaxial InP Solar Cell Structures

Science.gov (United States)

Chatterjee, B.; Davis, W. C.; Ringel, S. A.; Hoffman, R., Jr.

1995-01-01

Dislocations and related point defect complexes caused by lattice mismatch currently limit the performance of heteroepitaxial InP cells by introducing shunting paths across the active junction and by the formation of deep traps within the base region. We have previously demonstrated that plasma hydrogenation is an effective and stable means to passivate the electrical activity of such defects in specially designed heteroepitaxial InP test structures to probe hydrogen passivation at typical base depths within a cell structure. In this work, we present our results on the hydrogen passivation of actual heteroepitaxial n(+)p and p(+)n InP cell structures grown on GaAs substrates by metalorganic chemical vapor deposition (MOCVD). We have found that a 2 hour exposure to a 13.56 MHz hydrogen plasma at 275 C reduces the deep level concentration in the base regions of both n(+)p and p(+)n heteroepitaxial InP cell structures from as-grown values of 5 - 7 x 10(exp 14)/cc, down to 3 - 5 x 10(exp 12)/cc. All dopants were successfully reactivated by a 400 C, 5 minute anneal With no detectable activation of deep levels. I-V analysis indicated a subsequent approx. 100 fold decrease In reverse leakage current at -1 volt reverse bias, and an improved built in voltage for the p(+)n structures. ln addition to being passivated,dislocations are also shown to participate in secondary interactions during hydrogenation. We find that the presence of dislocations enhances hydrogen diffusion into the cell structure, and lowers the apparent dissociation energy of Zn-H complexes from 1.19 eV for homoepitaxial Zn-doped InP to 1.12 eV for heteroepitaxial Zn-doped InP. This is explained by additional hydrogen trapping at dislocations subsequent to the reactivation of Zn dopants after hydrogenation.

Hydrogen passivation of N(+)-P and P(+)-N heteroepitaxial InP solar cell structures

Science.gov (United States)

Chatterjee, Basab; Davis, William C.; Ringel, Steve A.; Hoffman, Richard, Jr.

1996-01-01

Dislocations and related point defect complexes caused by lattice mismatch currently limit the performance of heteroepitaxial InP cells by introducing shunting paths across the active junction and by the formation of deep traps within the base region. We have previously demonstrated that plasma hydrogenation is an effective and stable means to passivate the electrical activity of such defects in specially designed heteroepitaxial InP test structures to probe hydrogen passivation at typical base depths within a cell structure. In this work, we present our results on the hydrogen passivation of actual heteroepitaxial n-p and p-n InP cell structures grown on GaAs substrates by metalorganic chemical vapor deposition (MOCVD). We have found that a 2 hour exposure to a 13.56 MHz hydrogen plasma at 275 C reduces the deep level concentration in the base regions of both n(+)-p and p(+)-n heteroepitaxial InP cell structures from as-grown values of 5-7 x 10(exp 14) cm(exp -3), down to 3-5 x 10(exp 12) cm(exp -3). All dopants were successfully reactivated by a 400 C, 5 minute anneal with no detectable activation of deep levels. One to five analysis indicated a subsequent approximately 100 fold decrease in reverse leakage current at -1 volt reverse bias, and an improved built in voltage for the p(+)-n structures. In addition to being passivated, dislocations are also shown to participate in secondary interactions during hydrogenation. We find that the presence of dislocations enhances hydrogen diffusion into the cell structure, and lowers the apparent dissociation energy of Zn-H complexes from 1.19 eV for homoepitaxial Zn-doped InP to 1.12 eV for heteroepitaxial Zn-doped InP. This is explained by additional hydrogen trapping at dislocations subsequent to the reactivation of Zn dopants after hydrogenation.

Hydrogen concentration determination in pressure tube samples using differential scanning calorimetry (dsc)

International Nuclear Information System (INIS)

Marinescu, R.; Mincu, M.

2015-01-01

Zirconium alloys are widely used as a structural material in nuclear reactors. It is known that zirconium based cladding alloys absorb hydrogen as a result of service in a pressurized water reactor. Hydrogen absorbed (during operation of the reactor) in the zirconium alloy, out of which the pressure tube is made, is one of the major factors determining the life time of the pressure tube. For monitoring the hydrides, samples of the pressure tube are periodically taken and analyzed. At normal reactor operating temperature, hydrogen has limited solubility in the zirconium lattice and precipitates out of solid solution as zirconium hydride when the solid solubility is exceeded. As a consequences material characterization of Zr-2.5Nb CANDU pressure tubes is required after manufacturing but also during the operation to assess its structural integrity and to predict its behavior until the next in-service inspection. Hydrogen and deuterium concentration determination is one of the most important parameters to be evaluated during the experimental tests. Hydrogen present in zirconium alloys has a strong effect of weakening. Following the zirconium-hydrogen reaction, the resulting zirconium hydride precipitates in the mass of material. Weakening of the material, due to the presence of 10 ppm of precipitated hydrogen significantly affects some of its properties. The concentration of hydrogen in a sample can be determined by several methods, one of them being the differential scanning calorimetry (DSC). The principle of the method consists in measuring the difference between the amount of heat required to raise the temperature of a sample and a reference to a certain value. The experiments were made using a TA Instruments DSC Q2000 calorimeter. This paper contains experimental work for hydrogen concentration determination by Differential Scanning Calorimetry (DSC) method. Also, the reproducibility and accuracy of the method used at INR Pitesti are presented. (authors)

Sunlight to hydrogen conversion: Design optimization and energy management of concentrated photovoltaic (CPV-Hydrogen) system using micro genetic algorithm

KAUST Repository

Burhan, Muhammad

2016-02-14

Owing to the intermittent solar irradiance from cloud cover in the diurnal period and unavailability at night time, the practical design of a solar system requires energy backup storage for an uninterrupted supply or for off-grid operation. However, for highly efficient CPV (concentrated photovoltaic) system, the literature is lacking for energy management and optimization algorithm and tool for standalone operation. In this paper, a system with CPV and electrolyser is presented where beam irradiance of sunlight is harnessed to convert the instantaneously generated electricity into useful Hydrogen/Oxygen gas, where they can be stored and re-used for downstream applications such as the fuel cells, etc. The multi-variable design and multi-objective optimization strategies are proposed and presented for a standalone operation of the CPV-Hydrogen system as well as their system performances, particularly electrical rating of CPV based upon the real weather data of Singapore. © 2016 Elsevier Ltd.

Effect of substrate concentration on hydrogen production by photo-fermentation in the pilot-scale baffled bioreactor.

Science.gov (United States)

Lu, Chaoyang; Zhang, Zhiping; Zhou, Xuehua; Hu, Jianjun; Ge, Xumeng; Xia, Chenxi; Zhao, Jia; Wang, Yi; Jing, Yanyan; Li, Yameng; Zhang, Quanguo

2018-01-01

Effect of substrate concentration on photo-fermentative hydrogen production was studied with a self-designed 4m 3 pilot-scale baffled photo-fermentative hydrogen production reactor (BPHR). The relationships between parameters, such as hydrogen production rate (HPR, mol H 2 /m 3 /d), hydrogen concentration, pH value, oxidation-reduction potential, biomass concentration (volatile suspended solids, VSS) and reducing sugar concentration, during the photo-fermentative hydrogen production process were investigated. The highest HPR of 202.64±8.83mol/m 3 /d was achieved in chamber #3 at a substrate concentration of 20g/L. Hydrogen contents were in the range of 42.19±0.94%-49.71±0.27%. HPR increased when organic loading rate was increased from 3.3 to 20g/L/d, then decreased when organic loading rate was further increased to 25g/L/d. A maximum HPR of 148.65±4.19mol/m 3 /d was obtained when organic loading rate was maintained at 20g/L/d during continuous bio-hydrogen production. Copyright © 2017 Elsevier Ltd. All rights reserved.

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)

An Isotope Study of Hydrogenation of poly-Si/SiOx Passivated Contacts for Si Solar Cells: Preprint

Energy Technology Data Exchange (ETDEWEB)

Schnabel, Manuel; Nemeth, William; van de Loo, Bas, W.H.; Macco, Bart; Kessels, Wilhelmus, M.M.; Stradins, Paul; Young, David, L.

2017-06-26

For many years, the record Si solar cell efficiency stood at 25.0%. Only recently have several companies and institutes managed to produce more efficient cells, using passivated contacts of made doped poly-Si or a-Si:H and a passivating intrinsic interlayer in all cases. Common to these designs is the need to passivate the layer stack with hydrogen. In this contribution, we perform a systematic study of passivated contact passivation by hydrogen, using poly-Si/SiOx passivated contacts on n-Cz-Si, and ALD Al2O3 followed by a forming gas anneal (FGA) as the hydrogen source. We study p-type and n-type passivated contacts with implied Voc exceeding 690 and 720 mV, respectively, and perform either the ALD step or the FGA with deuterium instead of hydrogen in order to separate the two processes via SIMS. By examining the deuterium concentration at the SiOx in both types of samples, we demonstrate that the FGA supplies negligible hydrogen species to the SiOx, regardless of whether the FGA is hydrogenated or deuterated. Instead, it supplies the thermal energy needed for hydrogen species in the Al2O3 to diffuse there. Furthermore, the concentration of hydrogen species at the SiOx can saturate while implied Voc continues to increase, showing that the energy from the FGA is also required for hydrogen species already at the SiOx to find recombination-active defects to passivate.

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)

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.

A Self-Supported Direct Borohydride-Hydrogen Peroxide Fuel Cell System

Directory of Open Access Journals (Sweden)

Ashok K. Shukla

2009-04-01

Full Text Available A self-supported direct borohydride-hydrogen peroxide fuel cell system with internal manifolds and an auxiliary control unit is reported. The system, while operating under ambient conditions, delivers a peak power of 40 W with about 2 W to run the auxiliary control unit. A critical cause and effect analysis, on the data for single cells and stack, suggests the optimum concentrations of fuel and oxidant to be 8 wt. % NaBH4 and 2 M H2O2, respectively in extending the operating time of the system. Such a fuel cell system is ideally suited for submersible and aerospace applications where anaerobic conditions prevail.

OTEC to hydrogen fuel cells - A solar energy breakthrough

Science.gov (United States)

Roney, J. R.

Recent advances in fuel cell technology and development are discussed, which will enhance the Ocean Thermal Energy Conversion (OTEC)-hydrogen-fuel cell mode of energy utilization. Hydrogen obtained from the ocean solar thermal resources can either be liquified or converted to ammonia, thus providing a convenient mode of transport, similar to that of liquid petroleum. The hydrogen fuel cell can convert hydrogen to electric power at a wide range of scale, feeding either centralized or distributed systems. Although this system of hydrogen energy production and delivery has been examined with respect to the U.S.A., the international market, and especially developing countries, may represent the greatest opportunity for these future generating units.

Microbial Electrodialysis Cell for Simultaneous Water Desalination and Hydrogen Gas Production

KAUST Repository

Mehanna, Maha

2010-12-15

A new approach to water desalination is to use exoelectrogenic bacteria to generate electrical power from the biodegradation of organic matter, moving charged ions from a middle chamber between two membranes in a type of microbial fuel cell called a microbial desalination cell. Desalination efficiency using this approach is limited by the voltage produced by the bacteria. Here we examine an alternative strategy based on boosting the voltage produced by the bacteria to achieve hydrogen gas evolution from the cathode using a three-chambered system we refer to as a microbial electrodialysis cell (MEDC). We examined the use of the MEDC process using two different initial NaCl concentrations of 5 g/L and 20 g/L. Conductivity in the desalination chamber was reduced by up to 68 ± 3% in a single fed-batch cycle, with electrical energy efficiencies reaching 231 ± 59%, and maximum hydrogen production rates of 0.16 ± 0.05 m3 H2/m3 d obtained at an applied voltage of 0.55 V. The advantage of this system compared to a microbial fuel cell approach is that the potentials between the electrodes can be better controlled, and the hydrogen gas that is produced can be used to recover energy to make the desalination process self-sustaining with respect to electrical power requirements. © 2010 American Chemical Society.

Microbial Electrodialysis Cell for Simultaneous Water Desalination and Hydrogen Gas Production

KAUST Repository

Mehanna, Maha; Kiely, Patrick D.; Call, Douglas F.; Logan, Bruce. E.

2010-01-01

A new approach to water desalination is to use exoelectrogenic bacteria to generate electrical power from the biodegradation of organic matter, moving charged ions from a middle chamber between two membranes in a type of microbial fuel cell called a microbial desalination cell. Desalination efficiency using this approach is limited by the voltage produced by the bacteria. Here we examine an alternative strategy based on boosting the voltage produced by the bacteria to achieve hydrogen gas evolution from the cathode using a three-chambered system we refer to as a microbial electrodialysis cell (MEDC). We examined the use of the MEDC process using two different initial NaCl concentrations of 5 g/L and 20 g/L. Conductivity in the desalination chamber was reduced by up to 68 ± 3% in a single fed-batch cycle, with electrical energy efficiencies reaching 231 ± 59%, and maximum hydrogen production rates of 0.16 ± 0.05 m3 H2/m3 d obtained at an applied voltage of 0.55 V. The advantage of this system compared to a microbial fuel cell approach is that the potentials between the electrodes can be better controlled, and the hydrogen gas that is produced can be used to recover energy to make the desalination process self-sustaining with respect to electrical power requirements. © 2010 American Chemical Society.

Hydrogen fuel cell power system

International Nuclear Information System (INIS)

Lam, A.W.

2004-01-01

'Full text:' Batteries are typically a necessary and prime component of any DC power system, providing a source of on-demand stored energy with proven reliability. The integration of batteries and basic fuel cells for mobile and stationary utility applications poses a new challenge. For high value applications, the specification and operating requirements for this hybrid module differ from conventional requirements as the module must withstand extreme weather conditions and provide extreme reliability. As an electric utility company, BCHydro has embarked in the development and application of a Hydrogen Fuel Cell Power Supply (HFCPS) for field trial. A Proton Exchange Membrane (PEM)- type fuel cell including power electronic modules are mounted in a standard 19-inch rack that provides 48V, 24V, 12V DC and 120V AC outputs. The hydrogen supply consists of hydrogen bottles and regulating devices to provide a continuous fuel source to the power modules. Many tests and evaluations have been done to ensure the HFCPS package is robust and suitable for electric utility grade operation. A field trial demonstrating this standalone system addressed reliability, durability, and installation concerns as well as developed the overall system operating procedures. (author)

Saccharomyces cerevisiae has distinct adaptive responses to both hydrogen peroxide and menadione.

OpenAIRE

Jamieson, D J

1992-01-01

Treatment of Saccharomyces cerevisiae cells with low concentrations of either hydrogen peroxide or menadione (a superoxide-generating agent) induces adaptive responses which protect cells from the lethal effects of subsequent challenge with higher concentrations of these oxidants. Pretreatment with menadione is protective against cell killing by hydrogen peroxide; however, pretreatment with hydrogen peroxide is unable to protect cells from subsequent challenge with menadione. This suggests th...

2015 Annual Progress Report: DOE Hydrogen and Fuel Cells Program

Energy Technology Data Exchange (ETDEWEB)

None

2015-12-23

The 2015 Annual Progress Report summarizes fiscal year 2015 activities and accomplishments by projects funded by the DOE Hydrogen and Fuel Cells Program. It covers the program areas of hydrogen production; hydrogen delivery; hydrogen storage; fuel cells; manufacturing R&D; technology validation; safety, codes and standards; systems analysis; and market transformation.

Three-dimensional atomic mapping of hydrogenated polymorphous silicon solar cells

Energy Technology Data Exchange (ETDEWEB)

Chen, Wanghua, E-mail: wanghua.chen@polytechnique.edu; Roca i Cabarrocas, Pere [LPICM, CNRS, Ecole Polytechnique, Université Paris-Saclay, 91128 Palaiseau (France); Pareige, Philippe [GPM, CNRS, Université et INSA de Rouen, Normandie Université, 76801 Saint Etienne du Rouvray (France)

2016-06-20

Hydrogenated polymorphous silicon (pm-Si:H) is a nanostructured material consisting of silicon nanocrystals embedded in an amorphous silicon matrix. Its use as the intrinsic layer in thin film p-i-n solar cells has led to good cell properties in terms of stability and efficiency. Here, we have been able to assess directly the concentration and distribution of nanocrystals and impurities (dopants) in p-i-n solar cells, by using femtosecond laser-assisted atom probe tomography (APT). An effective sample preparation method for APT characterization is developed. Based on the difference in atomic density between hydrogenated amorphous and crystalline silicon, we are able to distinguish the nanocrystals from the amorphous matrix by using APT. Moreover, thanks to the three-dimensional reconstruction, we demonstrate that Si nanocrystals are homogeneously distributed in the entire intrinsic layer of the solar cell. The influence of the process pressure on the incorporation of nanocrystals and their distribution is also investigated. Thanks to APT we could determine crystalline fractions as low as 4.2% in the pm-Si:H films, which is very difficult to determine by standard techniques, such as X-ray diffraction, Raman spectroscopy, and spectroscopic ellipsometry. Moreover, we also demonstrate a sharp p/i interface in our solar cells.

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.

Hydrogen passivation of polycrystalline Si thin film solar cells

Energy Technology Data Exchange (ETDEWEB)

Gorka, Benjamin

2010-12-15

Hydrogen passivation is a key process step in the fabrication of polycrystalline Si (poly-Si) thin film solar cells. In this work a parallel plate rf plasma setup was used for the hydrogen passivation treatment. The main topics that have been investigated are (i) the role of plasma parameters (like hydrogen pressure, electrode gap and plasma power), (ii) the dynamics of the hydrogen treatment and (iii) passivation of poly-Si with different material properties. Passivation was characterized by measuring the open-circuit voltage V{sub OC} of poly-Si reference samples. Optimum passivation conditions were found by measurements of the breakdown voltage V{sub brk} of the plasma for different pressures p and electrode gaps d. For each pressure, the best passivation was achieved at a gap d that corresponded to the minimum in V{sub brk}. Plasma simulations were carried out, which indicate that best V{sub OC} corresponds to a minimum in ion energy. V{sub OC} was not improved by a larger H flux. Investigations of the passivation dynamic showed that a plasma treatment in the lower temperature range ({<=}400 C) is slow and takes several hours for the V{sub OC} to saturate. Fast passivation can be successfully achieved at elevated temperatures around 500 C to 600 C with a plateau time of 10 min. It was found that prolonged hydrogenation leads to a loss in V{sub OC}, which is less pronounced within the observed optimum temperature range (500 C-600 C). Electron beam evaporation has been investigated as an alternative method to fabricate poly-Si absorbers. The material properties have been tuned by alteration of substrate temperature T{sub dep}=200-700 C and were characterized by Raman, ESR and V{sub OC} measurements. Largest grains were obtained after solid phase crystallization (SPC) of a-Si, deposited in the temperature range of 300 C. The defect concentration of Si dangling bonds was lowered by passivation by about one order of magnitude. The lowest dangling bond concentration

Determination of hydrogen peroxide in water by chemiluminescence detection, (1). Flow injection type hydrogen peroxide detection system

International Nuclear Information System (INIS)

Yamashiro, Naoya; Uchida, Shunsuke; Satoh, Yoshiyuki; Morishima, Yusuke; Yokoyama, Hiroaki; Satoh, Tomonori; Sugama, Junichi; Yamada, Rie

2004-01-01

A flow injection type hydrogen peroxide detection system with a sub-ppb detection limit has been developed to determine hydrogen peroxide concentration in water sampled from a high temperature, high pressure hydrogen peroxide water loop. The hydrogen peroxide detector is based on luminol chemiluminescence spectroscopy. A small amount of sample water (20 μl) is mixed with a reagent mixture, an aqueous solution of luminol and Co 2+ catalyst, in a mixing cell which is installed just upstream from the detection cell. The optimum values for pH and the concentrations of luminol and Co 2+ ion have been determined to ensure a lower detectable limit and a higher reproducibility. The photocurrent detected by the detection system is expressed by a linear function of the hydrogen peroxide concentration in the region of lower concentration ([H 2 O 2 ] 2 O 2 ] in the region of higher concentration ([H 2 O 2 ] > 10 ppb). The luminous intensity of luminol chemiluminescence is the highest when pH of the reagent mixture is 11.0. Optimization of the major parameters gives the lowest detectable limit of 0.3 ppb. (author)

In situ measurements of hydrogen concentration and flux between 160 and 300 km in the thermosphere

International Nuclear Information System (INIS)

Breig, E.L.; Hanson, W.B.; Hoffman, J.H.; Kayser, D.C.

1976-01-01

Thermospheric concentrations of neutral atomic hydrogen near and below the F peak are directly related to H + , O + and atomic oxygen concentrations through the charge exchange equilibrium that is established between hydrogen and oxygen at these altitudes. This chemical relationship, together with in situ measurements of ionospheric and neutral atmospheric concentrations by instrumentation on board the Atmosphere Explorer C satellite, is utilized to investigate properties of neutral hydrogen at altitudes below 200 km where vertical diffusion strongly affects the hydrogen distribution. Data are discussed for a set of satellite orbits during quiet geomagnetic and solar conditions in February 1974; the resultant altitude variation of the derived hydrogen concentrations applies specifically to early afternoon at low 10 5 atoms/cm 3 is observed for these conditions at 300 km. At lower altitudes the concentration profiles are interpreted in terms of vertical hydrogen flow. The resultant daytime flux in the thermosphere is estimated to be (3.2 +- 1.0) x 10 8 atoms/cm 2 s. The present observations thus support theoretical estimates and model calculations of large hydrogen flow upward from the region below 100 km. They also support the concept of daytime thermospheric loss process of greater magnitude than the traditional evaporative escape mechanism

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

OpenAIRE

POPOVICI Ovidiu; HOBLE Dorel Anton

2012-01-01

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

A technique for measuring hydrogen and water in inert gases and the hydrogen concentration in liquid sodium

International Nuclear Information System (INIS)

Smith, C.A.

1978-04-01

A method is described of measuring the hydrogen and water content of an inert gas. It is based upon the use of an electrochemical oxygen cell and has a high sensitivity at low hydrogen and water levels. The following possible applications of the method are described together with supporting experimental measurements: improving the sensitivity and range of the present PFR secondary circuit hydrogen detection instruments; the measurement of hydrogen diffusion coefficients in steels; the measurement of waterside corrosion rates of boiler steels; on-line monitoring of waterside boiler corrosion. Attention is given to the characteristics of diffusion barriers in relation to the first and last of these. (author)

2016 Annual Progress Report: DOE Hydrogen and Fuel Cells Program

Energy Technology Data Exchange (ETDEWEB)

None, None

2017-03-09

The 2016 Annual Progress Report summarizes fiscal year 2016 activities and accomplishments by projects funded by the DOE Hydrogen and Fuel Cells Program. It covers the program areas of hydrogen production; hydrogen delivery; hydrogen storage; fuel cells; manufacturing R&D; technology validation; safety, codes and standards; systems analysis; market transformation; and Small Business Innovation Research projects.

Hydrogenated amorphous silicon coatings may modulate gingival cell response

Science.gov (United States)

Mussano, F.; Genova, T.; Laurenti, M.; Munaron, L.; Pirri, C. F.; Rivolo, P.; Carossa, S.; Mandracci, P.

2018-04-01

Silicon-based materials present a high potential for dental implant applications, since silicon has been proven necessary for the correct bone formation in animals and humans. Notably, the addition of silicon is effective to enhance the bioactivity of hydroxyapatite and other biomaterials. The present work aims to expand the knowledge of the role exerted by hydrogen in the biological interaction of silicon-based materials, comparing two hydrogenated amorphous silicon coatings, with different hydrogen content, as means to enhance soft tissue cell adhesion. To accomplish this task, the films were produced by plasma enhanced chemical vapor deposition (PECVD) on titanium substrates and their surface composition and hydrogen content were analyzed by means of X-ray photoelectron spectroscopy (XPS) and Fourier-transform infrared spectrophotometry (FTIR) respectively. The surface energy and roughness were measured through optical contact angle analysis (OCA) and high-resolution mechanical profilometry respectively. Coated surfaces showed a slightly lower roughness, compared to bare titanium samples, regardless of the hydrogen content. The early cell responses of human keratinocytes and fibroblasts were tested on the above mentioned surface modifications, in terms of cell adhesion, viability and morphometrical assessment. Films with lower hydrogen content were endowed with a surface energy comparable to the titanium surfaces. Films with higher hydrogen incorporation displayed a lower surface oxidation and a considerably lower surface energy, compared to the less hydrogenated samples. As regards mean cell area and focal adhesion density, both a-Si coatings influenced fibroblasts, but had no significant effects on keratinocytes. On the contrary, hydrogen-rich films increased manifolds the adhesion and viability of keratinocytes, but not of fibroblasts, suggesting a selective biological effect on these cells.

Hydrogen passivation of n+p and p+n heteroepitaxial InP solar cell structures

Science.gov (United States)

Chatterjee, B.; Ringel, S. A.; Hoffman, R., Jr.

1995-01-01

High-efficiency, heteroepitaxial (HE) InP solar cells, grown on GaAs, Si or Ge substrates, are desirable for their mechanically strong, light-weight and radiation-hard properties. However, dislocations, caused by lattice mismatch, currently limit the performance of the HE cells. This occurs through shunting paths across the active photovoltaic junction and by the formation of deep levels. In previous work we have demonstrated that plasma hydrogenation is an effective and stable means to passivate the electrical activity of dislocations in specially designed HE InP test structures. In this work, we present the first report of successful hydrogen passivation in actual InP cell structures grown on GaAs substrates by metalorganic chemical vapor deposition (MOCVD). We have found that a 2 hour exposure to a 13.56 MHz hydrogen plasma at 275 C reduces the deep level concentration in HE n+n InP cell structures from as-grown values of approximately 10(exp 15)/cm(exp -3), down to 1-2 x 10(exp 13)/cm(exp -3). The deep levels in the p-type base region of the cell structure match those of our earlier p-type test structures, which were attributed to dislocations or related point defect complexes. All dopants were successfully reactivated by a 400 C, 5 minute anneal with no detectable activation of deep levels. I-V analysis indicated a subsequent approximately 10 fold decrease in reverse leakage current at -1 volt reverse bias, and no change in the forward biased series resistance of the cell structure which indicates complete reactivation of the n+ emitter. Furthermore, electrochemical C-V profiling indicates greatly enhanced passivation depth, and hence hydrogen diffusion, for heteroepitaxial structures when compared with identically processed homoepitaxial n+p InP structures. An analysis of hydrogen diffusion in dislocated InP will be discussed, along with comparisons of passivation effectiveness for n+p versus p+n heteroepitaxial cell configurations. Preliminary hydrogen

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

Directory of Open Access Journals (Sweden)

POPOVICI Ovidiu

2012-10-01

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

Hydrogen storage and fuel cells

Science.gov (United States)

Liu, Di-Jia

2018-01-01

Global warming and future energy supply are two major challenges facing American public today. To overcome such challenges, it is imperative to maximize the existing fuel utilization with new conversion technologies while exploring alternative energy sources with minimal environmental impact. Hydrogen fuel cell represents a next-generation energy-efficient technology in transportation and stationary power productions. In this presentation, a brief overview of the current technology status of on-board hydrogen storage and polymer electrolyte membrane fuel cell in transportation will be provided. The directions of the future researches in these technological fields, including a recent "big idea" of "H2@Scale" currently developed at the U. S. Department of Energy, will also be discussed.

Nickel hydrogen battery cell storage matrix test

Science.gov (United States)

Wheeler, James R.; Dodson, Gary W.

1993-01-01

Test were conducted to evaluate post storage performance of nickel hydrogen cells with various design variables, the most significant being nickel precharge versus hydrogen precharge. Test procedures and results are presented in outline and graphic form.

KOH concentration effect on the cycle life of nickel-hydrogen cells. IV - Results of failure analysis

Science.gov (United States)

Lim, H. S.; Verzwyvelt, S. A.

1990-01-01

Potassium hydroxide concentration effects on the cycle life of a Ni/H2 cell have been studied by carrying out a cycle life test on ten Ni/H2 boiler plate cells which contain electrolytes of various KOH concentrations. Failure analyses of these cells were carried out after completion of the life test, which accumulated up to 40,000 cycles at an 80-percent depth of discharge over a period of 3.7 years. These failure analyses included studies on changes of electrical characteristics of test cells, and component analyses after disassembly of the cell. The component analyses included visual inspections, dimensional changes, capacity measurements of nickel electrodes, scanning electron microscopy, surface area measurements, and chemical analyses. Results have indicated that failure mode and change in the nickel electrode varied as the concentration was varied, especially when the concentration was changed from 31 percent or higher to 26 percent or lower.

77 FR 50488 - Hydrogen and Fuel Cell Technical Advisory Committee

Science.gov (United States)

2012-08-21

... DEPARTMENT OF ENERGY Hydrogen and Fuel Cell Technical Advisory Committee AGENCY: Department of...). SUMMARY: This notice announces an open meeting (Webinar) of the Hydrogen and Fuel Cell Technical Advisory... Avenue, Washington, DC 20585. SUPPLEMENTARY INFORMATION: Purpose of the Committee: The Hydrogen and Fuel...

The Effects of Bee Venom on PLA2 and Calcium Concentration in Raw 264.7 Cells

Directory of Open Access Journals (Sweden)

Jong-Il Yun

2003-06-01

Full Text Available Objectives : The purpose of this study was to investigate the effect of Bee Venom on the lipopolysaccharide, sodium nitroprusside and hydrogen peroxide induced expression phospholipase A2 and calcium concentration in RAW 264.7 cells, a murine macrophage cell line. Methods : The expression of phospholipase A2 was determined by western blotting with corresponding antibodies, and the generation of intracellular calcium concentration was investigated by delta scan system in RAW 264.7 cells. Results : 1. Compared with control, expressions of lipopolysaccharide-induced phospholipase A2 were decreased significantly by 1 ㎍/㎕ of bee venom and decreased by 0.5, 5 ㎍/㎕ of bee venom. 2. Compared with control, expressions of sodium nitroprusside-induced phospholipase A2 were decreased significantly by 5 ㎍/㎕ of bee venom but increased by 0.5, 5 ㎍/㎕ of bee venom. 3. Compared with control, expressions of hydrogen peroxide-induced phospholipase A2 were decreased significaltly by 1 ㎍/㎕ of bee venom and decreased by 0.5 ㎍/㎕ of bee venom but increased by 5 ㎍/㎕ of bee venom. 4. Compared with control, lipopolysaccharide, sodium nitroprusside and hydrogen peroxide- induced intracellular calcium concentrations were decreased by 0.5, 1, 5 ㎍/㎕ of bee venom and by indomethacin

78 FR 60866 - Hydrogen and Fuel Cell Technical Advisory Committee (HTAC)

Science.gov (United States)

2013-10-02

... DEPARTMENT OF ENERGY Hydrogen and Fuel Cell Technical Advisory Committee (HTAC) AGENCY: Office of...: This notice announces an open meeting of the Hydrogen and Fuel Cell Technical Advisory Committee (HTAC... Committee: The Hydrogen and Fuel Cell Technical Advisory Committee (HTAC) was established under section 807...

Sunlight to hydrogen conversion: Design optimization and energy management of concentrated photovoltaic (CPV-Hydrogen) system using micro genetic algorithm

International Nuclear Information System (INIS)

Burhan, Muhammad; Chua, Kian Jon Ernest; Ng, Kim Choon

2016-01-01

Owing to the intermittent solar irradiance from cloud cover in the diurnal period and unavailability at night time, the practical design of a solar system requires energy backup storage for an uninterrupted supply or for off-grid operation. However, for highly efficient CPV (concentrated photovoltaic) system, the literature is lacking for energy management and optimization algorithm and tool for standalone operation. In this paper, a system with CPV and electrolyser is presented where beam irradiance of sunlight is harnessed to convert the instantaneously generated electricity into useful Hydrogen/Oxygen gas, where they can be stored and re-used for downstream applications such as the fuel cells, etc. The multi-variable design and multi-objective optimization strategies are proposed and presented for a standalone operation of the CPV-Hydrogen system as well as their system performances, particularly electrical rating of CPV based upon the real weather data of Singapore. - Highlights: • Design modelling and energy management strategy is proposed for CPV-Hydrogen system. • Micro GA does multi-variable and multi-objective optimization for standalone operation. • Design is verified and analysed for minimum cost, zero PSFT and optimal storage. • Performance of each component is presented for different real weather data conditions. • Proposed design approach is applicable in all regions with low and high DNI.

Storage and production of hydrogen for fuel cell applications

Science.gov (United States)

Aiello, Rita

The increased utilization of proton-exchange membrane (PEM) fuel cells as an alternative to internal combustion engines is expected to increase the demand for hydrogen, which is used as the energy source in these systems. The objective of this work is to develop and test new methods for the storage and production of hydrogen for fuel cells. Six ligand-stabilized hydrides were synthesized and tested as hydrogen storage media for use in portable fuel cells. These novel compounds are more stable than classical hydrides (e.g., NaBH4, LiAlH4) and react to release hydrogen less exothermically upon hydrolysis with water. Three of the compounds produced hydrogen in high yield (88 to 100 percent of the theoretical) and at significantly lower temperatures than those required for the hydrolysis of NaBH4 and LiAlH4. However, a large excess of water and acid were required to completely wet the hydride and keep the pH of the reaction medium neutral. The hydrolysis of the classical hydrides with steam can overcome these limitations. This reaction was studied in a flow reactor and the results indicate that classical hydrides can be hydrolyzed with steam in high yields at low temperatures (110 to 123°C) and in the absence of acid. Although excess steam was required, the pH of the condensed steam was neutral. Consequently, steam could be recycled back to the reactor. Production of hydrogen for large-scale transportation fuel cells is primarily achieved via the steam reforming, partial oxidation or autothermal reforming of natural gas or the steam reforming of methanol. However, in all of these processes CO is a by-product that must be subsequently removed because the Pt-based electrocatalyst used in the fuel cells is poisoned by its presence. The direct cracking of methane over a Ni/SiO2 catalyst can produce CO-free hydrogen. In addition to hydrogen, filamentous carbon is also produced. This material accumulates on the catalyst and eventually deactivates it. The Ni/SiO2 catalyst

Variation of molecular hydrogen tropospheric concentration over Southern Poland - results of the continuous chromatographic measurements.

Science.gov (United States)

Necki, J.; Chmura, L.

2012-04-01

Although hydrogen is one of the fundamental constituents of the earth's atmosphere its global balance is still poorly clarified. A few developed inventories diverging values for efficiency of sources and sinks of this gas. The European network for the hydrogen concentrations measurement is based on several unevenly spaced measurement points. While in 2009 MPI Jena has delivered accurate scale for hydrogen measurements and the techniques of analyses are well described, still large areas of Central Europe is uncovered by representative stations. The first measurement point, established under the EUROHYDROS EU program, on the territory of Poland was Kraków city. Different laboratory setups was tested there and compared to each other. The Kraków area has significant car traffic and its geographical location implies frequent temperature inversions in lower troposphere leading to the accumulation of trace gases in atmosphere of the city. Observations launched in 2007 revealed that the concentration of hydrogen fluctuates strongly within diurnal and seasonal timescales. Its average concentration is three times larger than this, observed at the other stations. The European "background" concentrations of hydrogen are not reflected in the Krakow record. An ideal place to carry out observation of the regional air composition for Central Europe is a research station located in the meteorological observatory at Kasprowy Wierch. Measurement point at the top of mountain peak with elevation of 2000m a.s.l. gives an access to the well mixed troposphere. The station delivers also the necessary facilities and logistics. Since year 1996 greenhouse gas measurement program has been operating at this point. The first measurements of atmospheric concentrations of hydrogen at Kasprowy Wierch were performed in year 2010, based on dedicated gas chromatograph using RGD detector installed at the station. Analysis of hydrogen content in the outside air is performed without any enrichment

Hydrogen fuel injection - the bridge to fuel cells

International Nuclear Information System (INIS)

Gilchrist, J.S.

2004-01-01

'Full text:' For over a century, industry has embraced a wide variety of applications for hydrogen. Since the mid-1970's, the focus of the bulk of hydrogen research has been in the area of fuel cells. Unfortunately, there is limited awareness of more immediate applications for hydrogen as a catalyst designed to improve the performance of existing hydro-carbon fuelled internal combustion engines. Canadian Hydrogen Energy Company manufactures a patented Hydrogen Fuel Injection System (HFI) that produces hydrogen and oxygen from distilled water and injects them, in measured amounts, into the air intake system on any heavy-duty diesel or gasoline application including trucks, buses, stationary generators, etc. In use on over 30 fleets, research is supported by over 40 million miles of field data. The hydrogen acts as a catalyst to promote more complete combustion, with remarkable results. Dramatically reduce emissions, particularly Carbon Monoxide and Particulate Matter. Increase horsepower and torque. Improved fuel efficiency (a minimum 10% improvement is guaranteed). Reduced oil degradation The HFI system offers the first large-scale application of the use of hydrogen and an excellent bridge to the fuel-cell technologies of the future. (author)

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.

Hydrogen and fuel cells. Towards a sustainable energy future

International Nuclear Information System (INIS)

Edwards, P.P.; Kuznetsov, V.L.; David, W.I.F.; Brandon, N.P.

2008-01-01

A major challenge - some would argue, the major challenge facing our planet today - relates to the problem of anthropogenic-driven climate change and its inextricable link to our global society's present and future energy needs [King, D.A., 2004. Environment - climate change science: adapt, mitigate, or ignore? Science 303, 176-177]. Hydrogen and fuel cells are now widely regarded as one of the key energy solutions for the 21st century. These technologies will contribute significantly to a reduction in environmental impact, enhanced energy security (and diversity) and creation of new energy industries. Hydrogen and fuel cells can be utilised in transportation, distributed heat and power generation, and energy storage systems. However, the transition from a carbon-based (fossil fuel) energy system to a hydrogen-based economy involves significant scientific, technological and socioeconomic barriers to the implementation of hydrogen and fuel cells as clean energy technologies of the future. This paper aims to capture, in brief, the current status, key scientific and technical challenges and projection of hydrogen and fuel cells within a sustainable energy vision of the future. We offer no comments here on energy policy and strategy. Rather, we identify challenges facing hydrogen and fuel cell technologies that must be overcome before these technologies can make a significant contribution to cleaner and more efficient energy production processes. (author)

Hydrogen and fuel cell research: Institute for Integrated Energy Systems (IESVic)

International Nuclear Information System (INIS)

Pitt, L.

2006-01-01

Vision: IESVic's mission is to chart feasible paths to sustainable energy. Current research areas of investigation: 1. Energy system analysis 2. Computational fuel cell engineering; Fuel cell parameter measurement; Microscale fuel cells 3. Hydrogen dispersion studies for safety codes 4. Active magnetic refrigeration for hydrogen liquifaction and heat transfer in metal hydrides 5. Hydrogen and fuel cell system integration (author)

Solid oxide fuel cells and hydrogen production

International Nuclear Information System (INIS)

Dogan, F.

2009-01-01

'Full text': A single-chamber solid oxide fuel cell (SC-SOFC), operating in a mixture of fuel and oxidant gases, provides several advantages over the conventional SOFC such as simplified cell structure (no sealing required). SC-SOFC allows using a variety of fuels without carbon deposition by selecting appropriate electrode materials and cell operating conditions. The operating conditions of single chamber SOFC was studied using hydrocarbon-air gas mixtures for a cell composed of NiO-YSZ / YSZ / LSCF-Ag. The cell performance and catalytic activity of the anode was measured at various gas flow rates. The results showed that the open-circuit voltage and the power density increased as the gas flow rate increased. Relatively high power densities up to 660 mW/cm 2 were obtained in a SC-SOFC using porous YSZ electrolytes instead of dense electrolytes required for operation of a double chamber SOFC. In addition to propane- or methane-air mixtures as a fuel source, the cells were also tested in a double chamber configuration using hydrogen-air mixtures by controlling the hydrogen/air ratio at the cathode and the anode. Simulation of single chamber conditions in double chamber configurations allows distinguishing and better understanding of the electrode reactions in the presence of mixed gases. Recent research efforts; the effect of hydrogen-air mixtures as a fuel source on the performance of anode and cathode materials in single-chamber and double-chamber SOFC configurations,will be presented. The presentation will address a review on hydrogen production by utilizing of reversible SOFC systems. (author)

Asymmetric transfer hydrogenation by synthetic catalysts in cancer cells

Science.gov (United States)

Coverdale, James P. C.; Romero-Canelón, Isolda; Sanchez-Cano, Carlos; Clarkson, Guy J.; Habtemariam, Abraha; Wills, Martin; Sadler, Peter J.

2018-03-01

Catalytic anticancer metallodrugs active at low doses could minimize side-effects, introduce novel mechanisms of action that combat resistance and widen the spectrum of anticancer-drug activity. Here we use highly stable chiral half-sandwich organometallic Os(II) arene sulfonyl diamine complexes, [Os(arene)(TsDPEN)] (TsDPEN, N-(p-toluenesulfonyl)-1,2-diphenylethylenediamine), to achieve a highly enantioselective reduction of pyruvate, a key intermediate in metabolic pathways. Reduction is shown both in aqueous model systems and in human cancer cells, with non-toxic concentrations of sodium formate used as a hydride source. The catalytic mechanism generates selectivity towards ovarian cancer cells versus non-cancerous fibroblasts (both ovarian and lung), which are commonly used as models of healthy proliferating cells. The formate precursor N-formylmethionine was explored as an alternative to formate in PC3 prostate cancer cells, which are known to overexpress a deformylase enzyme. Transfer-hydrogenation catalysts that generate reductive stress in cancer cells offer a new approach to cancer therapy.

Hydrogen and Fuel Cells for IT Equipment

Energy Technology Data Exchange (ETDEWEB)

Kurtz, Jennifer

2016-03-09

With the increased push for carbon-free and sustainable data centers, data center operators are increasingly looking to renewable energy as a means to approach carbon-free status and be more sustainable. The National Renewable Energy Laboratory (NREL) is a world leader in hydrogen research and already has an elaborate hydrogen infrastructure in place at the Golden, Colorado, state-of-the-art data center and facility. This presentation will discuss hydrogen generation, storage considerations, and safety issues as they relate to hydrogen delivery to fuel cells powering IT equipment.

Ensuring safety of fuel cell applications and hydrogen refuelling. Legislation and standards; Polttokennosovellusten ja vetytankkauksen turvallisuuden varmistaminen. Saeaedoeksiae ja standardeja

Energy Technology Data Exchange (ETDEWEB)

Nissila, M.; Sarsama, J.

2013-09-15

Fuel cell technology is considered a promising alternative in terms of viable energy systems. The advantages of fuel cell systems include a good efficiency rate and the lack of harmful environmental emissions. Factors which may slow down the commercialisation of fuel cell technology, e.g. fuel cell vehicles, include the high price of hydrogen and the insufficiency of the infrastructure required for the distribution of hydrogen. A large proportion of major car manufacturers are committed to introducing fuel cell cars to the market by 2014-2016. In order to ensure a successful market introduction of fuel cell vehicles, this has to be aligned with the development of the necessary hydrogen infrastructure. In the early commercialisation stages of a new technology, it is important to give the public correct, justified and understandable information on the safety of the fuel cell applications, and also on the measures taken to ensure the safety of applications. A lack of necessary information, inaccurate perceptions and prejudices can have an adverse effect on the public acceptance of fuel cell applications. Hazards and potential accidents related to fuel cell systems are mainly associated with the flammable substances (e.g. hydrogen, methane) used as fuel, the high pressure of hydrogen, electrical hazards, and dangers concerning technical systems in general. The fuel cell applications reviewed in this publication are transport applications and stationary applications and the refuelling system of gaseous hydrogen. The publication concentrates on fuel cells using hydrogen as fuel. The publication gives an overview of how EU-legislation (mainly various directives) and Finnish legislation applies to fuel cell systems and applications, and what kind of safety requirements the legislation sets. In addition, a brief overview of safety standards concerning fuel cell systems and hydrogen refuelling is presented. (orig.)

Control of hydrogen concentration in reactor containment buildings by using passive catalytic recombiners

International Nuclear Information System (INIS)

Wolff, U.

1993-01-01

Severe accidents in nuclear power plants have the potential to generate hydrogen within the reactor containment building in concentrations likely to deflagrate or even detonate. This could endanger the containment integrity. Autocatalytic devices have been developed by the NIS company in Hanau, Germany, to control the hydrogen concentration within the containment. These devices have been tested by the Battelle Institute in Frankfurt, Germany, under conditions relevant to severe accidents. The catalytic device functions as required in a wide band of gas mixtures ranging from inerted conditions with low-hydrogen and/or low-oxygen concentrations up to detonable mixtures. The device starts up quickly, and has a high resistance against catalyst poisons including the effects of oil or cable fires. The device makes a strong contribution to gas mixing in the containment atmosphere. The paper summarizes the development work done and describes the final design of the device. Theoretical tools for analysis and prediction of catalyst performance in containment environments have been developed by the Battelle Institute and the Technical University of Munich. These tools have been verified and validated against experimental data. A phenomenological discussion of accident scenarios is used to explain the functional requirements for the autocatalytic devices in the control of hydrogen. Both the potential for and limitations of such devices for hydrogen control are discussed for large dry containments (PWRs) and for those which are originally inerted (BWRs)

Sodium Borohydride/Hydrogen Peroxide Fuel Cells For Space Application

Science.gov (United States)

Valdez, T. I.; Deelo, M. E.; Narayanan, S. R.

2006-01-01

This viewgraph presentation examines Sodium Borohydride and Hydrogen Peroxide Fuel Cells as they are applied to space applications. The topics include: 1) Motivation; 2) The Sodium Borohydride Fuel Cell; 3) Sodium Borohydride Fuel Cell Test Stands; 4) Fuel Cell Comparisons; 5) MEA Performance; 6) Anode Polarization; and 7) Electrode Analysis. The benefits of hydrogen peroxide as an oxidant and benefits of sodium borohydride as a fuel are also addressed.

Fuel Cell Electric Vehicle Evaluations | Hydrogen and Fuel Cells | NREL

Science.gov (United States)

Electric Vehicle Evaluations Fuel Cell Electric Vehicle Evaluations NREL's technology validation team analyzes hydrogen fuel cell electric vehicles (FCEVs) operating in a real-world setting to include commercial FCEVs for the first time. Current fuel cell electric vehicle evaluations build on the

Canadian fuel cell commercialization roadmap update : progress of Canada's hydrogen and fuel cell industry

International Nuclear Information System (INIS)

Filbee, S.; Karlsson, T.

2009-01-01

Hydrogen and fuel cells are considered an essential part of future low-carbon energy systems for transportation and stationary power. In recognition of this, Industry Canada has worked in partnership with public and private stakeholders to provide an update to the 2003 Canadian Fuel Cell Commercialization Roadmap to determine infrastructure requirements for near-term markets. The update includes technology and market developments in terms of cost and performance. This presentation included an overview of global hydrogen and fuel cell markets as background and context for the activities of the Canadian industry. Approaches toward commercial viability and mass market success were also discussed along with possible scenarios and processes by which these mass markets could develop. Hydrogen and fuel cell industry priorities were outlined along with recommendations for building a hydrogen infrastructure

Method of monitoring CO concentrations in hydrogen feed to a PEM fuel cell

Science.gov (United States)

Grot, Stephen Andreas; Meltser, Mark Alexander; Gutowski, Stanley; Neutzler, Jay Kevin; Borup, Rodney Lynn; Weisbrod, Kirk

2000-01-01

The CO concentration in the H.sub.2 feed stream to a PEM fuel cell stack is monitored by measuring current and/or voltage behavior patterns from a PEM-probe communicating with the reformate feed stream. Pattern recognition software may be used to compare the current and voltage patterns from the PEM-probe to current and voltage telltale outputs determined from a reference cell similar to the PEM-probe and operated under controlled conditions over a wide range of CO concentrations in the H.sub.2 fuel stream. The PEM-probe is intermittently purged of any CO build-up on the anode catalyst (e.g., by (1) flushing the anode with air, (2) short circuiting the PEM-probe, or (3) reverse biasing the PEM-probe) to keep the PEM-probe at peak performance levels.

Life cycle assessment of hydrogen production and fuel cell systems

International Nuclear Information System (INIS)

Dincer, I.

2007-01-01

This paper details life cycle assessment (LCA) of hydrogen production and fuel cell system. LCA is a key tool in hydrogen and fuel cell technologies for design, analysis, development; manufacture, applications etc. Energy efficiencies and greenhouse gases and air pollution emissions have been evaluated in all process steps including crude oil and natural gas pipeline transportation, crude oil distillation, natural gas reprocessing, wind and solar electricity generation , hydrogen production through water electrolysis and gasoline and hydrogen distribution and utilization

Stress distributions due to hydrogen concentrations in electrochemically charged and aged austenitic stainless steel

International Nuclear Information System (INIS)

Rozenak, P.; Loew, A.

2008-01-01

As a result of hydrogen concentration gradients in type austenitic stainless steels, formed during electrochemical charging and followed by hydrogen loss during aging, at room temperature, surface stresses were developed. These stresses were measured by X-ray technique and the crack formation thus induced could be studied using equilibrium stress equations. After various electrochemical charging and aging times, X-ray diffraction patterns obtained from samples indicated that the reflected and broadened diffraction peaks are the result of the formation of a non-uniform but continuous solid solution in the austenitic matrix. Since both hydrogen penetrations during charging and hydrogen release during aging are diffusion controlled processes and huge hydrogen concentration gradients in the thin surface layer, at depths comparable with the depth of X-ray penetration, are observed. The non-uniform hydrogen concentration in the austenitic matrix, results to the non-uniform expansion of the atomic microstructure and latter inevitably leads to the development of internal stresses. The internal stresses development formulae's are very similar to those relating to non-uniform heating of the materials, where thermal stresses appear due to non-uniform expansion or contraction. The relevant well developed theory is applicable in our case of non-uniform hydrogen concentrations in a solid solution of electrochemically charged and aged austenitic matrix. A few cracks were present on the surface after some minutes of electrochemical charging and the severity of cracking increased as hydrogen was lost during subsequent aging. This is consistent with the expectation of high compressive stresses in the bulk of the specimen during charging and high tensile surface stresses (at the level of 1 x 10 11 Pa) during the aging process. These stresses can induce the formation of surface cracks during the aging process after electrochemical charging in the AISI 316 stainless steel

Energy conversion using hydrogen PEM fuel cells

International Nuclear Information System (INIS)

Stoenescu, D.; Patularu, L.; Culcer, M.; Lazar, R.; Mirica, D.; Varlam, M.; Carcadea, E.; Stefanescu, I.

2004-01-01

It is well known that hydrogen is the most promising solution of future energy, both for long and medium term strategies. Hydrogen can be produced using many primary sources (naphthalene, natural gas, methanol, coal, biomass), solar cells power, etc. It can be burned or chemically reacted having a high yield of energy conversion and is a non-polluted fuel. This paper presents the results obtained by ICSI Rm. Valcea in an experimental-demonstrative conversion energy system consisting in a catalytic methane reforming plant for hydrogen production and three synthesis gas purification units in order to get pure hydrogen with a CO level lower than 10 ppm that finally feeds a hydrogen fuel stock. (authors)

Hydrogen energy and fuel cells. A vision of our future

International Nuclear Information System (INIS)

2003-01-01

Hydrogen and fuel cells are seen by many as key solutions for the 21 century, enabling clean efficient production of power and heat from a range of primary energy sources. The High Level Group for Hydrogen and Fuel Cells Technologies was initiated in October 2002 by the Vice President of the European Commission, Loyola de Palacio, Commissioner for Energy and Transport, and Mr Philippe Busquin, Commissioner for Research. The group was invited to formulate a collective vision on the contribution that hydrogen and fuel cells could make to the realisation of sustainable energy systems in future. The report highlights the need for strategic planning and increased effort on research, development and deployment of hydrogen and fuel cell technologies. It also makes wide-ranging recommendations for a more structured approach to European Energy policy and research, for education and training, and for developing political and public awareness. Foremost amongst its recommendations is the establishment of a European Hydrogen and Fuel Cell Technology Partnership and Advisory Council to guide the process. (author)

Hydrogen energy and fuel cells. A vision of our future

Energy Technology Data Exchange (ETDEWEB)

NONE

2003-07-01

Hydrogen and fuel cells are seen by many as key solutions for the 21 century, enabling clean efficient production of power and heat from a range of primary energy sources. The High Level Group for Hydrogen and Fuel Cells Technologies was initiated in October 2002 by the Vice President of the European Commission, Loyola de Palacio, Commissioner for Energy and Transport, and Mr Philippe Busquin, Commissioner for Research. The group was invited to formulate a collective vision on the contribution that hydrogen and fuel cells could make to the realisation of sustainable energy systems in future. The report highlights the need for strategic planning and increased effort on research, development and deployment of hydrogen and fuel cell technologies. It also makes wide-ranging recommendations for a more structured approach to European Energy policy and research, for education and training, and for developing political and public awareness. Foremost amongst its recommendations is the establishment of a European Hydrogen and Fuel Cell Technology Partnership and Advisory Council to guide the process. (author)

COMPENDIUM: SURVEYS EVALUATING KNOWLEDGE AND OPINIONS CONCERNING HYDROGEN AND FUEL CELL TECHNOLOGIES

Energy Technology Data Exchange (ETDEWEB)

Truett, Lorena Faith [ORNL; Cooper, Christy [U.S. Department of Energy; Schmoyer, Richard L [ORNL

2008-10-01

information for many of the surveys is collected face-to-face or electronically; however, all of the DOE surveys are conducted via telephone interviews. Most of the surveys concentrated on a specific population group, while the DOE surveys addressed five different populations (general public, students, government agencies, end users, and safety and codes officials). No survey (except the DOE survey) conducted since 2003 surveyed students knowledge and opinions of hydrogen and fuel cells. Although several surveys have solicited opinions of users (e.g., passengers of fuel-cell vehicles), no surveys were conducted of end users (industrial users needing large power supplies, commercial users needing uninterrupted power, or transportation businesses). While the International Organization for Standardization (ISO) has surveyed its membership concerning standards, the population of safety and codes officials has not been surveyed. The greatest impact and importance of the DOE surveys is that five distinct population groups are surveyed for both knowledge and opinions on hydrogen and fuel cells. Knowledge levels can be computed for each population group and can be compared across the populations and across time. Opinions can be compared with knowledge levels. A baseline of knowledge levels was derived using the results of the 2004 surveys; this baseline will be compared with the results of the knowledge evaluation for the surveys of 2008/2009 and 2011/2012. The DOE knowledge and opinion surveys are unique in coverage and purpose. It must be noted, however, that response rates for telephone surveys have decreased dramatically over time. Developments in survey methodology research will have to be followed over the next few years so that necessary adjustments are made in the 20112012 DOE hydrogen survey design, to account for cell-phone-only individuals as well as other changes in telephone usage demographics.

Hydrogen & fuel cells: advances in transportation and power

National Research Council Canada - National Science Library

Hordeski, Michael F

2009-01-01

... race, it became more of an economics issue since as long as petroleum was available and cheap there was no need to develop a hydrogen technology. Now, we see much more investment in fuel cell technology, hydrogen fueled vehicles and even hydrogen fuel stations. The technology is being pushed by economics as oil prices continue to rise with dwind...

Effect of pH and sulfate concentration on hydrogen production using anaerobic mixed microflora

Energy Technology Data Exchange (ETDEWEB)

Hwang, Jae-Hoon; Choi, Jeong-A.; Bhatnagar, Amit; Kumar, Eva; Jeon, Byong-Hun [Department of Environmental Engineering, Yonsei University, Wonju, Gangwon-do, 220-710 (Korea); Abou-Shanab, R.A.I. [Department of Environmental Engineering, Yonsei University, Wonju, Gangwon-do, 220-710 (Korea); Department of Environmental Biotechnology, Mubarak City for Scientific Research, Alexandria (Egypt); Min, Booki [Department of Environmental Science and Engineering, Kyung Hee University, Yongin-Si, Gyeonggi-Do 446-701 (Korea); Song, Hocheol; Kim, Yong Je [Geologic Environment Division, KIGAM, Daejeon, 305-350 (Korea); Choi, Jaeyoung [Korea Institute of Science and Technology (KIST), Gangneung Institute, Gangneung 210-340 (Korea); Lee, Eung Seok [Geological Sciences, College of Arts and Sciences, Ohio University, Athens, OH 45701-2979 (United States); Um, Sukkee [School of Mechanical Engineering, Hanyang University, 17 Haengdang-Dong, Seongdong-Gu, Seoul, 133-791 (Korea); Lee, Dae Sung [Petroleum and Marine Research Department, KIGAM, Daejeon (Korea)

2009-12-15

The effects of varying sulfate concentrations with pH on continuous fermentative hydrogen production were studied using anaerobic mixed cultures growing on a glucose substrate in a chemostat reactor. The maximum hydrogen production rate was 2.8 L/day at pH 5.5 and sulfate concentration of 3000 mg/L. Hydrogen production and residual sulfate level decreased with increasing the pH from 5.5 to 6.2. The volatile fatty acids (VFAs) and ethanol fractions in the effluent were in the order of butyric acid (HBu) > acetic acid (HAc) > ethanol > propionic acid (HPr). Fluorescence In Situ Hybridization (FISH) analysis revealed the presence of hydrogen producing bacteria (HPB) under all pH ranges while sulfate reducing bacteria (SRB) were present at pH 5.8 and 6.2. The inhibition in hydrogen production by SRB at pH 6.2 diminished entirely by lowering to pH 5.5, at which activity of SRB is substantially suppressed. (author)

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)

KOH concentration effect on the cycle life of nickel-hydrogen cells. Part 4: Results of failure analyses

Science.gov (United States)

Lim, H. S.; Verzwyvelt, S. A.

1989-01-01

KOH concentration effects on cycle life of a Ni/H2 cell have been studied by carrying out a cycle life test of ten Ni/H2 boiler plate cells which contain electrolytes of various KOH concentrations. Failure analyses of these cells were carried out after completion of the life test which accumulated up to 40,000 cycles at an 80 percent depth of discharge over a period of 3.7 years. These failure analyses included studies on changes of electrical characteristics of test cells and component analyses after disassembly of the cell. The component analyses included visual inspections, dimensional changes, capacity measurements of nickel electrodes, scanning electron microscopy, BET surface area measurements, and chemical analyses. Results have indicated that failure mode and change in the nickel electrode varied as the concentration was varied, especially, when the concentration was changed from 31 percent or higher to 26 percent or lower.

Evaluation of local stress and local hydrogen concentration at grain boundary using three-dimensional polycrystalline model

International Nuclear Information System (INIS)

Ebihara, Ken-ichi; Itakura, Mitsuhiro; Yamaguchi, Masatake; Kaburaki, Hideo; Suzudo, Tomoaki

2010-01-01

The decohesion model in which hydrogen segregating at grain boundaries reduces cohesive energy is considered to explain hydrogen embrittlement. Although there are several experimental and theoretical supports of this model, its total process is still unclear. In order to understand hydrogen embrittlement in terms of the decohesion model, therefore, it is necessary to evaluate stress and hydrogen concentration at grain boundaries under experimental conditions and to verify the grain boundary decohesion process. Under this consideration, we evaluated the stress and the hydrogen concentration at grain boundaries in the three-dimensional polycrystalline model which was generated by the random Voronoi tessellation. The crystallographic anisotropy was given to each grain. As the boundary conditions of the calculations, data extracted from the results calculated in the notched round-bar specimen model under the tensile test condition in which fracture of the steel specimen is observed was given to the polycrystalline model. As a result, it was found that the evaluated stress does not reach the fracture stress which was estimated under the condition of the evaluated hydrogen concentration by first principles calculations. Therefore, it was considered that the initiation of grain boundary fracture needs other factors except the stress concentration due to the crystallographic anisotropy. (author)

Analysis of Hydrogen Concentration Distribution during an SBO Accident for Shin-Ulchin APR1400

Energy Technology Data Exchange (ETDEWEB)

Kim, Jongtae; Hong, Seong Wan [Korea Atomic energy Research Institute, Daejeon (Korea, Republic of)

2013-10-15

To prohibit the accumulation of hydrogen, the containment volume is considered to reduce the hydrogen concentration, or hydrogen mitigation devices such as PARs or igniters are installed in the containment. In the case of the Fukushima NPPs, the applied strategy for the hydrogen safety is the use of a containment venting system (CVS). In this way, the hydrogen accumulated in the containment vessel is vented into the environment. One of the causes of the hydrogen explosions occurring in the containment buildings of the Fukushima NPPs is expected to be the failure of the venting system. The hydrogen was therefore easily accumulated in the containment building. It is uncertain what the ignition source for the hydrogen combustion was during the accident. However, it is not too conservative to assume that an ignition source exists at any time and any place in a containment during a core-melt accident. Shin-Ulchin 1 and 2, which are construction plants of an APR 1400, are two of the newest NPPs in Korea. They have many features to enhance the safety margin during a design-based and beyond-design-based accident. One of them is the in-containment refueling water storage tank (IRWST) located inside the containment. It is used as a sink/source for feed-bleed operation. When the core is damaged along an accident progression, the hydrogen generated in the RPV can be released into the IRWST of the APR1400 with steam and water. From a previous study, it was found that a highly concentrated hydrogen/air mixture can be developed if the hydrogen is released into the IRWST. In the case of Shin-Ulchin 1 and 2, the hydrogen mitigation strategy during a high-pressure accident such as a station blackout (SBO) is changed by installing a 3-way valve. When a severe accident management (SAM) for the plant is initiated, the flow path from a pressurizer to the IRWST is changed into a steam-generator (S/G) compartment by turning the 3-wat valve actively (pilot operated). By doing so, it is

Measurement of the para-hydrogen concentration in the ISIS moderators using neutron transmission and thermal conductivity

Science.gov (United States)

Romanelli, Giovanni; Rudić, Svemir; Zanetti, Matteo; Andreani, Carla; Fernandez-Alonso, Felix; Gorini, Giuseppe; Krzystyniak, Maciej; Škoro, Goran

2018-04-01

We present an experimental study to determine the para-hydrogen concentration in the hydrogen moderators at the ISIS pulsed neutron and muon source. The experimental characterisation is based on neutron transmission experiments performed on the VESUVIO spectrometer, and thermal conductivity measurements using the TOSCA para-hydrogen rig. A reliable estimation of the level of para-hydrogen concentration in the hydrogen moderators is of crucial importance in the framework of a current project to completely refurbish the first target station at ISIS. Moreover, we report a new measurement of the total neutron cross section for normal hydrogen at 15 K on the broad energy range 3 meV -10 eV suggesting a revision of the most recent nuclear libraries for incident neutron energies lower than 10 meV. Finally, we characterise systematic errors affecting the para-hydrogen level estimation due to conversion from para to ortho hydrogen, as a function of the time a batch of gas spends in every component of our gas panel and apparatus.

78 FR 6086 - Hydrogen and Fuel Cell Technical Advisory Committee (HTAC)

Science.gov (United States)

2013-01-29

... DEPARTMENT OF ENERGY Hydrogen and Fuel Cell Technical Advisory Committee (HTAC) AGENCY: Office of...). SUMMARY: This notice announces an open meeting (Webinar) of the Hydrogen and Fuel Cell Technical Advisory... Avenue, Washington, DC 20585. SUPPLEMENTARY INFORMATION: Purpose of the Committee: The Hydrogen and Fuel...

77 FR 2714 - Hydrogen and Fuel Cell Technical Advisory Committee (HTAC)

Science.gov (United States)

2012-01-19

... DEPARTMENT OF ENERGY Hydrogen and Fuel Cell Technical Advisory Committee (HTAC) AGENCY: Department.... SUMMARY: This notice announces an open meeting of the Hydrogen and Fuel Cell Technical Advisory Committee... posted on http://hydrogen.energy.gov ). Public Comment (10 minutes) Discussion of HTAC's draft annual...

Hydrogen peroxide oxidant fuel cell systems for ultra-portable applications

Science.gov (United States)

Valdez, T. I.; Narayanan, S. R.

2001-01-01

This paper will address the issues of using hydrogen peroxide as an oxidant fuel in a miniature DMFC system. Cell performance for DMFC based fuel cells operating on hydrogen peroxide will be presented and discussed.

Action plan for coordinated deployment of hydrogen fuel cell vehicles and hydrogen infrastructure

International Nuclear Information System (INIS)

Elrick, W.

2009-01-01

This paper discussed a program designed to provide hydrogen vehicles and accessible hydrogen stations for a pre-commercial hydrogen economy in California. The rollout will coordinate the placement of stations in areas that meet the needs of drivers in order to ensure the transition to a competitive marketplace. An action plan has been developed that focuses on the following 3 specific steps: (1) the validation of early passenger vehicle markets, (2) expanded transit bus use, and (2) the establishment of regulations and standards. Specific tasks related to the steps were discussed, as well as potential barriers to the development of a hydrogen infrastructure in California. Methods of ensuring coordinated actions with the fuel cell and hydrogen industries were also reviewed

77 FR 65542 - Hydrogen and Fuel Cell Technical Advisory Committee (HTAC)

Science.gov (United States)

2012-10-29

... DEPARTMENT OF ENERGY Office of Energy Efficiency and Renewable Energy Hydrogen and Fuel Cell... Energy. ACTION: Notice of Open Meeting. SUMMARY: The Hydrogen and Fuel Cell Technical Advisory Committee... Agenda: (updates will be posted on the web at: http://hydrogen.energy.gov ). Public Comment DOE Program...

76 FR 4645 - Hydrogen and Fuel Cell Technical Advisory Committee (HTAC)

Science.gov (United States)

2011-01-26

... DEPARTMENT OF ENERGY Hydrogen and Fuel Cell Technical Advisory Committee (HTAC) AGENCY: Department...: This notice announces a meeting of the Hydrogen and Fuel Cell Technical Advisory Committee (HTAC). HTAC... Agenda: (Subject to change; updates will be posted on http://hydrogen.energy.gov and copies of the final...

76 FR 60478 - Hydrogen and Fuel Cell Technical Advisory Committee (HTAC)

Science.gov (United States)

2011-09-29

... DEPARTMENT OF ENERGY Hydrogen and Fuel Cell Technical Advisory Committee (HTAC) AGENCY: Department...: The Hydrogen and Fuel Cell Technical Advisory Committee (HTAC) was established under section 807 of... website at: http://hydrogen.energy.gov and copies of the final agenda will available the date of the...

75 FR 59705 - Hydrogen and Fuel Cell Technical Advisory Committee (HTAC)

Science.gov (United States)

2010-09-28

... DEPARTMENT OF ENERGY Hydrogen and Fuel Cell Technical Advisory Committee (HTAC) AGENCY: Department...: The Hydrogen and Fuel Cell Technical Advisory Committee (HTAC) was established under section 807 of... Agenda Topics: (Subject to change; updates will be posted on the web at http://hydrogen.energy.gov and...

75 FR 2860 - Hydrogen and Fuel Cell Technical Advisory Committee (HTAC)

Science.gov (United States)

2010-01-19

... DEPARTMENT OF ENERGY Office of Energy Efficiency and Renewable Energy Hydrogen and Fuel Cell... Energy. ACTION: Notice of Open Meeting. SUMMARY: The Hydrogen and Fuel Cell Technical Advisory Committee... change; updates will be posted on http://hydrogen.energy.gov and copies of the final agenda will...

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

Energy Technology Data Exchange (ETDEWEB)

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

2002-09-01

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

Hydrogen production profiles using furans in microbial electrolysis cells.

Science.gov (United States)

Catal, Tunc; Gover, Tansu; Yaman, Bugra; Droguetti, Jessica; Yilancioglu, Kaan

2017-06-01

Microbial electrochemical cells including microbial fuel cells (MFCs) and microbial electrolysis cells (MECs) are novel biotechnological tools that can convert organic substances in wastewater or biomass into electricity or hydrogen. Electroactive microbial biofilms used in this technology have ability to transfer electrons from organic compounds to anodes. Evaluation of biofilm formation on anode is crucial for enhancing our understanding of hydrogen generation in terms of substrate utilization by microorganisms. In this study, furfural and hydroxymethylfurfural (HMF) were analyzed for hydrogen generation using single chamber membrane-free MECs (17 mL), and anode biofilms were also examined. MECs were inoculated with mixed bacterial culture enriched using chloroethane sulphonate. Hydrogen was succesfully produced in the presence of HMF, but not furfural. MECs generated similar current densities (5.9 and 6 mA/cm 2 furfural and HMF, respectively). Biofilm samples obtained on the 24th and 40th day of cultivation using aromatic compounds were evaluated by using epi-fluorescent microscope. Our results show a correlation between biofilm density and hydrogen generation in single chamber MECs.

Hydrogen fuel cells for cars and buses

NARCIS (Netherlands)

Janssen, L.J.J.

2007-01-01

The use of hydrogen fuel cells for cars is strongly promoted by the governments of many countries and by international organizations like the European Community. The electrochem. behavior of the most promising fuel cell (polymer electrolyte membrane fuel cell, PEMFC) is critically discussed, based

Optimization of membrane stack configuration for efficient hydrogen production in microbial reverse-electrodialysis electrolysis cells coupled with thermolytic solutions

KAUST Repository

Luo, Xi

2013-07-01

Waste heat can be captured as electrical energy to drive hydrogen evolution in microbial reverse-electrodialysis electrolysis cells (MRECs) by using thermolytic solutions such as ammonium bicarbonate. To determine the optimal membrane stack configuration for efficient hydrogen production in MRECs using ammonium bicarbonate solutions, different numbers of cell pairs and stack arrangements were tested. The optimum number of cell pairs was determined to be five based on MREC performance and a desire to minimize capital costs. The stack arrangement was altered by placing an extra low concentration chamber adjacent to anode chamber to reduce ammonia crossover. This additional chamber decreased ammonia nitrogen losses into anolyte by 60%, increased the coulombic efficiency to 83%, and improved the hydrogen yield to a maximum of 3.5mol H2/mol acetate, with an overall energy efficiency of 27%. These results improve the MREC process, making it a more efficient method for renewable hydrogen gas production. © 2013 Elsevier Ltd.

Hydrogen-oxygen fuel cells

Czech Academy of Sciences Publication Activity Database

Vondrák, Jiří; Klápště, Břetislav; Velická, Jana; Sedlaříková, M.; Černý, R.

2003-01-01

Roč. 8, č. 1 (2003), s. 44-47 ISSN 1432-8488 R&D Projects: GA ČR GA203/02/0983; GA AV ČR IAA4032002 Institutional research plan: CEZ:AV0Z4032918 Keywords : electrocatalysis * hydrogen electrode Ionex membrane * membrane fuel cell Subject RIV: CA - Inorganic Chemistry Impact factor: 1.195, year: 2003

SPE (tm) regenerative hydrogen/oxygen fuel cells for extraterrestrial surface and microgravity applications

Science.gov (United States)

Mcelroy, J. F.

1990-01-01

Viewgraphs on SPE regenerative hydrogen/oxygen fuel cells for extraterrestrial surface and microgravity applications are presented. Topics covered include: hydrogen-oxygen regenerative fuel cell energy storage system; electrochemical cell reactions; SPE cell voltage stability; passive water removal SPE fuel cell; fuel cell performance; SPE water electrolyzers; hydrophobic oxygen phase separator; hydrophilic/electrochemical hydrogen phase separator; and unitized regenerative fuel cell.

Electrocatalysis research for fuel cells and hydrogen production

CSIR Research Space (South Africa)

Mathe, MK

2012-01-01

Full Text Available The CSIR undertakes research in the Electrocatalysis of fuel cells and for hydrogen production. The Hydrogen South Africa (HySA) strategy supports research on electrocatalysts due to their importance to the national beneficiation strategy. The work...

Improved fuel-cell-type hydrogen sensor

Science.gov (United States)

Rudek, F. P.; Rutkowski, M. D.

1968-01-01

Modified hydrogen sensor replaces oxygen cathode with a cathode consisting of a sealed paste of gold hydroxide and a pure gold current collector. The net reaction which occurs during cell operation is the reduction of the gold hydroxide to gold and water, with a half-cell potential of 1.4 volts.

Hydrogen evolution in enzymatic photoelectrochemical cell using modified seawater electrolytes produced by membrane desalination process

Energy Technology Data Exchange (ETDEWEB)

Joo, Hyunku; Yoon, Jaekyung [Hydrogen Energy Research Center, New and Renewable Energy Research Division, Korea Institute of Energy Research, 71-2 Jang-dong, Yuseong-gu, Daejeon 305-343 (Korea); Bae, Sanghyun [Department of Environmental Engineering, Yonsei University, 234 Maeji-ri, Hungub-myun, Wonju, Gangwon-do 220-710 (Korea); Kim, Chunghwan; Kim, Suhan [Korea Institute of Water and Environment, K-Water, 462-1 Jeonmin-dong, Yuseong-gu, Daejeon 305-730 (Korea)

2009-09-15

In the near future, potential water shortages are expected to occur all over the world and this problem will have a significant influence on the availability of water for water-splitting processes, such as photocatalysis and electrolysis, as well as for drinking water. For this reason, it has been suggested that seawater could be used as an alternative for the various water industries including hydrogen production. Seawater contains a large amount of dissolved ion components, thus allowing it to be used as an electrolyte in photoelectrochemical (PEC) systems for producing hydrogen. Especially, the concentrate (retentate) stream shows higher salinity than the seawater fed to the membrane desalination process, because purified water (fresh water) is produced as the permeate stream and the waste brine is more concentrated than the original seawater. In this study, we investigated the hydrogen evolution rate in a photoelectrochemical system, including the preparation and characterization of an anodized tubular TiO{sub 2} electrode (ATTE) as both the photoanode and the cathode with the assistance of an immobilized hydrogenase enzyme and an external bias (solar cell), and the use of various qualities of seawater produced by membrane desalination processes as the electrolyte. The results showed that the rate of hydrogen evolution obtained using the nanofiltration (NF) retentate in the PEC system is ca. 105 {mu}mol/cm{sup 2} h, showing that this is an effective seawater electrolyte for hydrogen production, the optimum amount of enzyme immobilized on the cathode is ca. 3.66 units per geometrical unit area (1 cm x 1 cm), and the optimum external external bias supplied by the solar cell is 2.0 V. (author)

Hydrogen-bonded structure in highly concentrated aqueous LiBr solutions

International Nuclear Information System (INIS)

Imano, Masahiro; Kameda, Yasuo; Usuki, Takeshi; Uemura, Osamu

2001-01-01

Neutron diffraction measurements were carried out for H/D isotopically substituted aqueous 10, 25 and 33 mol% LiBr solutions in order to obtain structural information on the intermolecular hydrogen bonds among water molecules in highly concentrated aqueous solutions. Observed scattering cross sections for D 2 O (99.9 % D), 0 H 2 O(35.9 % D) and 0-2 H 2 O(68.0 % D) solutions were combined to deduce partial structure factors, a HH (Q), a XH (Q) and a XX (Q) (X: O, Br and Li). The least squares fitting analysis was applied to the observed partial structure factors to determine the nearest neighbor interatomic distance, root-mean-square amplitude and coordination number. Intermolecular distances, r OH =1.91(1) A, r HH =2.38(1) A and r OO =3.02(1) A, between the nearest neighbor water molecules, were obtained for the 10 mol% LiBr solution. On the other hand, the intermolecular O···H interaction was found to almost disappear in concentrated 25 and 33 mol% LiBr solutions. The result implies that the hydrogen-bonded network is completely broken in highly concentrated aqueous LiBr solutions. (author)

Hydrogen sulfide concentration in Beaver Dam Creek

International Nuclear Information System (INIS)

Kiser, D.L.

1979-01-01

Concentration-time profiles calculated with LODIPS for various hypothetical releases of hydrogen sulfide from the heavy water extraction facility predict lethal conditions for swamp fish from releases as small as 568 kg discharged over a period of 30 minutes or from releases of 1818 kg discharged over a period of 6 hours or less. The necessary volatilization and oxidation coefficients for LODIPS were derived from field measurements following planned releases of H 2 S. Upsets in the operation of the wastewater strippers in the Girdler-Sulfide (GS) heavy water extraction facility in D Area have released significant amounts of dissolved H 2 S to Beaver Dam Creek. Because H 2 S is toxic to fish in concentrations as low as 1 mg/liter, the downstream environmental impact of H 2 S releases from D Area was evaluated

British Columbia hydrogen and fuel cell strategy : an industry vision for our hydrogen future

Energy Technology Data Exchange (ETDEWEB)

NONE

2004-05-15

British Columbia's strategy for global leadership in hydrogen fuel cell technology was outlined. It was suggested that hydrogen and fuel cells will power a significant portion of the province by 2020, and will be used in homes, businesses, industry and transportation. The following 3 streams of activity were identified as leading to the achievement of this vision: (1) a hydrogen highway of technology demonstrations in vehicles, refuelling facilities and stationary power systems in time for and building on the 2010 Winter Olympic and Paralympic Games, (2) the development of a globally leading sustainable energy technology cluster that delivers products and services as well as securing high-value jobs, and (3) the renewal of the province's resource heartlands to supply the fuel and knowledge base for hydrogen-based communities and industries, and clean hydrogen production and distribution. It was suggested that in order to achieve the aforementioned goals, the government should promote the hydrogen highway and obtain $135 million in funding from various sources. It was recommended that the BC government and members of industry should also work with the federal government and other provinces to make Canada an early adopter market. Creative markets for BC products and services both in Canada and abroad will be accomplished by global partnerships, collaboration with Alberta and the United States. It was suggested that in order to deploy clean energy technologies, BC must integrate their strategy into the province's long-term sustainable energy plan. It was concluded that the hydrogen and fuel cell cluster has already contributed to the economy through jobs, private sector investment and federal and provincial tax revenues. The technology cluster's revenues have been projected at $3 billion with a workforce of 10,000 people by 2010. The hydrogen economy will reduce provincial air emissions, improve public health, and support sustainable tourism

Fuel options for the fuel cell vehicle: hydrogen, methanol or gasoline?

International Nuclear Information System (INIS)

Thomas, C.E.; James, B.D.; Lomax, F.D. Jr.; Kuhn, I.F. Jr.

2000-01-01

Fuel cell vehicles can be powered directly by hydrogen or, with an onboard chemical processor, other liquid fuels such as gasoline or methanol. Most analysts agree that hydrogen is the preferred fuel in terms of reducing vehicle complexity, but one common perception is that the cost of a hydrogen infrastructure would be excessive. According to this conventional wisdom, the automobile industry must therefore develop complex onboard fuel processors to convert methanol, ethanol or gasoline to hydrogen. We show here, however, that the total fuel infrastructure cost to society including onboard fuel processors may be less for hydrogen than for either gasoline or methanol, the primary initial candidates currently under consideration for fuel cell vehicles. We also present the local air pollution and greenhouse gas advantages of hydrogen fuel cell vehicles compared to those powered by gasoline or methanol. (Author)

Fuel cell commercialization: The key to a hydrogen economy

Science.gov (United States)

Zegers, P.

With the current level of global oil production, oil reserves will be sufficient for 40 years. However, due to the fact that the global GDP will have increased by a factor seven in 2050, oil reserves are likely to be exhausted in a much shorter time period. The EU and car industry aim at a reduction of the consumption of oil, at energy savings (with a key role for fuel cells) and an increased use of hydrogen from natural gas and, possibly, coal, in the medium term. The discovery of huge methane resources as methane hydrates (20 times those of oil, gas and coal together) in oceans at 1000-3000 m depth could be of major importance. In the long term, the EU aims at a renewable energy-based energy supply. The European Hydrogen and Fuel Cell Technology Platform is expected to play a major role in bringing about a hydrogen economy. The availability of commercial fuel cells is here a prerequisite. However, after many years of research, fuel cells have not yet been commercialized. If they will not succeed to enter the market within 5 years there is a real danger that activities aiming at a hydrogen society will peter out. In a hydrogen strategy, high priority should therefore be given to actions which will bring about fuel cell commercialization within 5 years. They should include the identification of fuel cell types and (niche) markets which are most favorable for a rapid market introduction. These actions should include focused short-term RTD aiming at cost reduction and increased reliability.

The study of hydrogen peroxide level under cisplatin action using genetically encoded sensor hyper

Science.gov (United States)

Belova, A. S.; Orlova, A. G.; Maslennikova, A. V.; Brilkina, A. A.; Balalaeva, I. V.; Antonova, N. O.; Mishina, N. M.; Shakhova, N. M.; Belousov, V. V.

2014-03-01

The aim of the work was to study the participation of hydrogen peroxide in reaction of cervical cancer cell line HeLa Kyoto on cisplatin action. Determination of hydrogen peroxide level was performed using genetically encoded fluorescent sensor HyPer2. The dependence of cell viability on cisplatin concentration was determined using MTT assay. Mechanisms of cell death as well as HyPer2 reaction was revealed by flow cytometry after 6-hours of incubation with cisplatin in different concentrations. Cisplatin used in low concentrations had no effect on hydrogen peroxide level in HeLa Kyoto cells. Increase of HyPer2 fluorescence was detected only after exposure with cisplatin in high concentration. The reaction was not the consequence of cell death.

Hydrogen Passivation of Interstitial Zn Defects in Heteroepitaxial InP Cell Structures and Influence on Device Characteristics

Science.gov (United States)

Ringel, S. A.; Chatterjee, B.

2004-01-01

Hydrogen passivation of heteroepitaxial InP solar cells is of recent interest for deactivation of dislocations and other defects caused by the cell/substrate lattice mismatch that currently limit the photovoltaic performance of these devices. In this paper we present strong evidence that, in addition to direct hydrogen-dislocation interactions, hydrogen forms complexes with the high concentration of interstitial Zn defects present within the p(+) Zn-doped emitter of MOCVD-grown heteroepitaxial InP devices, resulting in a dramatic increase of the forward bias turn-on voltage by as much as 280 mV, from 680 mV to 960 mV. This shift is reproducible and thermally reversible and no such effect is observed for either n(+)p structures or homoepitaxial p(+)n structures grown under identical conditions. A combination of photoluminescence (PL), electrochemical C-V dopant profiling, SIMS and I-V measurements were performed on a set of samples having undergone a matrix of hydrogenation and post-hydrogenation annealing conditions to investigate the source of this voltage enhancement and confirm the expected role of interstitial Zn and hydrogen. A precise correlation between all measurements is demonstrated which indicates that Zn interstitials within the p(+) emitter and their interaction with hydrogen are indeed responsible for this device behavior.

Salicylic acid induces apoptosis in colon carcinoma cells grown in-vitro: Influence of oxygen and salicylic acid concentration

International Nuclear Information System (INIS)

Zitta, Karina; Meybohm, Patrick; Bein, Berthold; Huang, Ying; Heinrich, Christin; Scholz, Jens; Steinfath, Markus; Albrecht, Martin

2012-01-01

In solid tumors the hypoxic environment can promote tumor progression and resistance to therapy. Recently, acetylsalicylic acid a major component of analgesic drugs and its metabolite salicylic acid (SA) have been shown to reduce the risk of colon cancer, but the mechanisms of action remain still unclear. Here we elucidate the effects of physiologically relevant concentrations of SA on colon carcinoma cells (CaCo-2) grown under normoxic and hypoxic conditions. Western blotting, caspase-3/7 apoptosis assays, MTS cell-proliferation assays, LDH cytotoxicity assays and hydrogen peroxide measurements were performed to investigate the effects of 1 and 10 μM SA on CaCo-2 cells grown under normoxic conditions and cells exposed to hypoxia. Under normoxic conditions, SA did not influence cell proliferation or LDH release of CaCo-2 cells. However, caspase-3/7 activity was significantly increased. Under hypoxia, cell proliferation was reduced and LDH release and caspase-3/7 activities were increased. None of these parameters was altered by the addition of SA under hypoxic conditions. Hypoxia increased hydrogen peroxide concentrations 300-fold and SA significantly augmented the release of hydrogen peroxide under normoxic, but not under hypoxic conditions. Phosphorylation of the pro-survival kinases akt and erk1/2 was not changed by SA under hypoxic conditions, whereas under normoxia SA reduced phosphorylation of erk1/2 after 2 hours. We conclude that in colon carcinoma cells effects of SA on apoptosis and cellular signaling are dependent on the availability of oxygen. -- Highlights: ► Effects of salicylic acid on colon carcinoma cells grown under normoxic and hypoxic conditions ► Salicylic acid increases caspase-3/7 activity and hydrogen peroxide release under normoxia ► Salicylic acid decreases pro-survival erk-1/2 phosphorylation under normoxia ► Salicylic acid does not influence any of the investigated parameters under hypoxia

Proceedings of the 5th International workshop on hydrogen and fuel cells WICaC 2010

Energy Technology Data Exchange (ETDEWEB)

NONE

2010-07-01

The 5th International Workshop on Hydrogen and Fuel Cells - WICaC 2010 aims to bring the most recent advances on fuel cell and hydrogen technologies. The conference will address the trends on hydrogen production, distribution, delivery, storage and infrastructure as well as fuel cell research, development, demonstration and commercialization. Some of the issues addressed at WICaC 2010 are: the official Brazilian hydrogen and fuel cell programs and its participation in the international programs and partnerships such as the IPHE (The International Partnership for Hydrogen and Fuel Cells in the Economy); the integration of renewable energy sources with hydrogen and fuel cell systems; the challenges to deploy the commercialization and use of fuel cells and hydrogen; distributed generation of energy; fuel cell uses in portable devices and in vehicles; life-cycle assessment of fuel cells and hydrogen technologies; environmental aspects; energy efficiency.

An analysis on local hydrogen concentration in the large dry PWR containment of Ulchin 3,4 in Korea

International Nuclear Information System (INIS)

Hong, S.W.; Kim, H.D.; Chung, S.H.

1994-01-01

The local hydrogen concentration was analyzed during two different severe accident scenarios (TMLB' and medium size LOCA) using CONTAIN code for the Ulchin 3,4 PWR containment type which is under construction in Korea. Sensitivity studies on the equivalent fraction of zirconium oxidation in the reactor vessel and the flow loss coefficient in the flow path between compartments were also carried out in order to investigate the effect of the these parameters on the local hydrogen concentration. Finally, the effect of temperature and turbulence intensity on the flame velocity was evaluated, and a sample calculation was performed by updating the model of the CONTAIN code. The calculated results show that the maximum local hydrogen concentration appears in the cavity compartment. lie hydrogen burn, however, is not likely to occur in this compartment for both scenarios due to low oxygen concentrations. Hydrogen burns are more likely to occur at the stern generator compartments for TMLB' accident and at the reactor vessel annulus compartment during medium size LOCA When the equivalent fraction of in-vessel zirconium oxidation is assumed to be 75 %, the possibility of detonation is much more increased. The change of flow loss coefficients between flow paths about 2 times affects on the magnitude of the maximum local hydrogen concentration but nearly no influence on the timing and the location of the compartment attaining the maximum local hydrogen concentration. The local hydrogen concentration in the compartments seems to be stratified after vessel failure but to be stabilized afterwards. When temperature and turbulence intensity are considered in the flame velocity model, the flame speed is much greater than the previous results, but the containment load is not increased very much. (author)

Hydrogen - the energy source of the future

International Nuclear Information System (INIS)

Aakervik, Anne-Lise

2001-01-01

The use of hydrogen is an excellent way of reducing the emission of greenhouse gases. It causes no emission when used in fuel cells. Iceland has set itself the goal of becoming the world's first hydrogen society without emission of carbon dioxide and other greenhouse gases. In the USA, California has decided to concentrate on cars that do not pollute. Hydrogen power is then an interesting alternative. Germany, Japan and the USA are all concentrating on hydrogen. The world production of hydrogen is 50 million tons, 90 per cent of which is made from fossil material, 4 per cent by electrolysis of water. The largest consumers of hydrogen are the petroleum industry and the fertilizer industry. The sale of hydrogen in the refining industry has increased recently and is expected to rise substantially when the fuel cell technology is commercialized. At present, storage of hydrogen is the major problem. Gas storage at atmospheric pressure is inconvenient because of the large volumes required. Alternatives are storage as compressed gas under high pressure, liquid gas at low temperature, storage in metal hydrides or carbon materials, or chemically bound in methanol or ammonia

New electrocatalysts for hydrogen-oxygen fuel cells

Science.gov (United States)

Cattabriga, R. A.; Giner, J.; Parry, J.; Swette, L. L.

1970-01-01

Platinum-silver, palladium-gold, and platinum-gold alloys serve as oxygen reduction catalysts in high-current-density cells. Catalysts were tested on polytetrafluoroethylene-bonded cathodes and a hydrogen anode at an operating cell temperature of 80 degrees C.

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)

Effects of ion concentration on the hydrogen bonded structure of ...

Indian Academy of Sciences (India)

WINTEC

Effects of ion concentration on the hydrogen bonded structure of water in the vicinity of ions in aqueous NaCl solutions. A NAG. 1. , D CHAKRABORTY and A CHANDRA*. Department of Chemistry, Indian Institute of Technology, Kanpur 208 016. 1. Present address: Department of Chemistry and Chemical Engineering,.

Electrolyte management considerations in modern nickel/hydrogen and nickel/cadmium cells and battery designs

Energy Technology Data Exchange (ETDEWEB)

Thaller, L.H. [The Aerospace Corporation, El Segundo, CA (United States); Zimmermann, A.H. [The Aerospace Corporation, El Segundo, CA (United States)

1996-11-01

While attention has been paid to understanding and modeling abnormal nickel/hydrogen cell behaviors, not enough attention has been paid to the potassium ion content in these cells, and more recently, in batteries. This paper will review three general areas where the potassium ion content can impact the performance and life of nickel/hydrogen and nickel/cadmium cells. Sample calculations of the concentration or volume changes that can take place within operating cells will be presented. With the aid of an accurate model of an operating cell or battery, the impact of changes of potassium ion content within a potential cell design can be estimated. All three of these areas are directly related to the volume tolerance and pore size engineering aspects of the components used in the cell or battery design. the three areas follow. (i) The gamma phase uptake of potassium ion can result in a lowering of the electrolyte concentration. This leads to a higher electrolyte resistance as well as electrolyte diffusional limitations on the discharge rate. This phenomenon also impacts the response of the cell to a reconditioning cycle. (ii) The transport of water vapor from a warmer to a cooler portion of the cell or battery under the driving force of a vapor pressure gradient has already impacted cells when water vapor condenses on a colder cell wall. This paper will explore the convective and diffusive movement of gases saturated with water vapor from a warmer plate pack to a cooler one, both with and without liquid communication. (iii) The impact of low level shunt currents in multicell configurations results in the net movement of potassium hydroxide from one part of the battery to another. This movement impacts the electrolyte volume/vapor pressure relationship within the cell or battery. (orig.)

Fuel cells: yes, please, but not fuelled with hydrogen

International Nuclear Information System (INIS)

Bossel, U.

2004-01-01

This short article takes a critical look at the fuel cell scene and criticises the fact that the word 'hydrogen' is almost always mentioned in the same breath as 'fuel cells'. Fundamental zeal that ignores physical reality and the technical possibilities available has, according to the author, led to politicians and journalists ignoring the laws of physics. The fact that hydrogen is not a source of energy but a synthetic energy carrier is stressed. The use of electricity - even if generated from renewable resources - to produce hydrogen is criticised on account of the conversion efficiencies involved. Figures are given on the overall efficiencies of a hydrogen-based energy-chain. The author recommends that novel, efficient methods of storing electricity should be promoted instead

Building the hydrogen/fuel cell industry: an EDC perspective

International Nuclear Information System (INIS)

FitzGerald, A.

2004-01-01

'Full text:' Canada has world-leading expertise in a number of hydrogen and fuel cell research segments. However, there are no guarantees that a strong research position necessarily translates into a large industry sector. The challenge facing Canada is to remain a leader in the coming years and decades as this hub of research activity evolves into an actual business sector. Many other countries are actively investing in hydrogen and fuel cell research. If these countries and their national governments are more committed than Canada to this commercial pursuit, then we will be left behind. Mr. Stothart's presentation will highlight a number of observations and recommendations regarding what is needed to build a successful hydrogen and fuel cell sector in Canada. (author)

Research at the service of energy transition - Hydrogen and fuel cells

International Nuclear Information System (INIS)

Bodineau, Luc; Antoine, Loic; Tonnet, Nicolas; Theobald, Olivier; Tappero, Denis

2018-03-01

This brochure brings together 22 hydrogen-energy and fuel cell projects selected and supported by the French agency of environment and energy management (Ademe) since 2012 through its call for research projects TITEC (industrial tests and transfers in real conditions) and Sustainable Energy: 1 - BHYKE: electric-hydrogen bike experiment; 2 - CHYMENE: innovative hydrogen compressor for mobile applications; 3 - COMBIPOL 3: bipolar plates assembly technology and gasketing process for PEMFC; 4 - CRONOS: high temperature SOFC for domestic micro-cogeneration; 5 - EPILOG: natural gas fuel cell on the way to commercialization; 6 - EXALAME: polyfunctional catalytic complexes for membranes-electrodes assembly without Nafion for PEMFC; 7 - HYCABIOME: H 2 and CO 2 conversion by biological methanation; 8 - HYLOAD: hydrogen-fueled airport vehicle experiment with on-site supply chain; 9 - HYSPSC: Pressurized hydrogen without Compressor; 10 - HYWAY: hydrogen mobility cluster demonstrator (electric-powered Kangoo cars fleet with range extender) at Lyon and Grenoble; 11 - MHYEL: Pre-industrialization of composite hybrid Membranes for PEM electrolyzer; 12 - NAVHYBUS: Design and experimentation of an electric-hydrogen river shuttle for passengers transportation at Nantes; 13 - PACMONT: fuel cells integration and adaptation for high mountain and polar applications; 14 - PREMHYOME: fabrication process of hybrid membranes for PEMFC; 15 - PRODIG: lifetime prediction and warranty for fuel cell systems; 16 - REHYDRO: fuel cell integration in the circular economy principle; 17 - SPHYNX and Co: optimizing renewable energy integration and self-consumption in buildings; 18 - THEMIS: design and experimentation of an autonomous on-site power supply system; 19 - VABHYOGAZ: biogas valorization through renewable hydrogen generation, design and experimentation of a 5 Nm 3 /h demonstrator at a waste disposal site; 20 - VALORPAC: Integration and experimentation of a high-temperature SOFC system that use

Influence of n,γ-field fluctuations on critical hydrogen concentration in the reactor primary coolant

International Nuclear Information System (INIS)

Arkhipov, O.; Kabakchi, S.

2014-01-01

One of the problems arising in operation of the NPP with reactors VVER/PWR are the consequences of the primary coolant radiolysis, namely, generation of the oxidizing particles intensifying the equipment corrosion rate. During operation of the reactor a decrease in concentration of oxidizing radiolysis products is provided with introduction of molecular hydrogen into the coolant. In this connection, the reliable estimation of Critical Hydrogen Concentration (CHC), sufficient for suppression of formation of oxidizing radiolysis products under specific in-pile conditions (reactor radiation dose rate, temperature, coolant chemical composition) is of practical interest. Unfortunately, the experimental data on CHC in-pile determination differ essentially from the values calculated. Critical hydrogen concentration is in the region of kinetic instability of radiation-chemical system. A slight change in hydrogen concentration leads to a sharp (by several orders) change in concentration of both short-lived (OH, HO 2 ) and stable (O 2 , H 2 O 2 ) oxidizing particles. In essence, when reaching the CHC, the radiation-chemical system changes over from one stable state to another. The paper deals with the results of the computer simulation of influence of short-term n,γ- field fluctuations on changing of the radiation-chemical system from the state with low concentration of oxidizing particles over to the state with their high concentrations. It is demonstrated that for the correct calculation of CHC in the primary coolant of VVER/PWR the non-uniformity of n,γ-field in the core shall be taken into account. (author)

Hydrogen Research for Spaceport and Space-Based Applications: Fuel Cell Projects

Science.gov (United States)

Anderson, Tim; Balaban, Canan

2008-01-01

The activities presented are a broad based approach to advancing key hydrogen related technologies in areas such as fuel cells, hydrogen production, and distributed sensors for hydrogen-leak detection, laser instrumentation for hydrogen-leak detection, and cryogenic transport and storage. Presented are the results from research projects, education and outreach activities, system and trade studies. The work will aid in advancing the state-of-the-art for several critical technologies related to the implementation of a hydrogen infrastructure. Activities conducted are relevant to a number of propulsion and power systems for terrestrial, aeronautics and aerospace applications. Fuel cell research focused on proton exchange membranes (PEM), solid oxide fuel cells (SOFC). Specific technologies included aircraft fuel cell reformers, new and improved electrodes, electrolytes, interconnect, and seals, modeling of fuel cells including CFD coupled with impedance spectroscopy. Research was conducted on new materials and designs for fuel cells, along with using embedded sensors with power management electronics to improve the power density delivered by fuel cells. Fuel cell applications considered were in-space operations, aviation, and ground-based fuel cells such as; powering auxiliary power units (APUs) in aircraft; high power density, long duration power supplies for interplanetary missions (space science probes and planetary rovers); regenerative capabilities for high altitude aircraft; and power supplies for reusable launch vehicles.

Determining air quality and greenhouse gas impacts of hydrogen infrastructure and fuel cell vehicles.

Science.gov (United States)

Stephens-Romero, Shane; Carreras-Sospedra, Marc; Brouwer, Jacob; Dabdub, Donald; Samuelsen, Scott

2009-12-01

Adoption of hydrogen infrastructure and hydrogen fuel cell vehicles (HFCVs) to replace gasoline internal combustion engine (ICE) vehicles has been proposed as a strategy to reduce criteria pollutant and greenhouse gas (GHG) emissions from the transportation sector and transition to fuel independence. However, it is uncertain (1) to what degree the reduction in criteria pollutants will impact urban air quality, and (2) how the reductions in pollutant emissions and concomitant urban air quality impacts compare to ultralow emission gasoline-powered vehicles projected for a future year (e.g., 2060). To address these questions, the present study introduces a "spatially and temporally resolved energy and environment tool" (STREET) to characterize the pollutant and GHG emissions associated with a comprehensive hydrogen supply infrastructure and HFCVs at a high level of geographic and temporal resolution. To demonstrate the utility of STREET, two spatially and temporally resolved scenarios for hydrogen infrastructure are evaluated in a prototypical urban airshed (the South Coast Air Basin of California) using geographic information systems (GIS) data. The well-to-wheels (WTW) GHG emissions are quantified and the air quality is established using a detailed atmospheric chemistry and transport model followed by a comparison to a future gasoline scenario comprised of advanced ICE vehicles. One hydrogen scenario includes more renewable primary energy sources for hydrogen generation and the other includes more fossil fuel sources. The two scenarios encompass a variety of hydrogen generation, distribution, and fueling strategies. GHG emissions reductions range from 61 to 68% for both hydrogen scenarios in parallel with substantial improvements in urban air quality (e.g., reductions of 10 ppb in peak 8-h-averaged ozone and 6 mug/m(3) in 24-h-averaged particulate matter concentrations, particularly in regions of the airshed where concentrations are highest for the gasoline scenario).

pH buffers for sea water media based on the total hydrogen ion concentration scale

Science.gov (United States)

Dickson, Andrew G.

1993-01-01

Published e.m.f. values measured using the cell ? where p° = 101.325 kPa, and BH + and B are the conjugate acid-base pairs of 2-aminopyridine, 2-amino-2-hydroxymethyl-1,3-propanediol (tris), tetrahydro-1,4-isoxazine (morpholine), and 2-amino-2-methyl-1, 3-propanediol (bis), have been re-evaluated to assign pH values based on the "total" hydrogen ion concentration scale to equimolal ( m =0.04 mol kg -1) buffer solutions based on these compounds. These pH values are consistent with the best available equilibrium constants for acid-base processes in sea water and such pH buffers can be used as pH calibration standards to measure accurate values for oceanic pH on the "total" hydrogen ion pH scale. In addition, the published e.m.f. results for these various amine bases have been used to calculate their respective acidity constants on this pH scale.

Elastic recoil detection analysis for the determination of hydrogen concentration profiles in switchable mirrors

NARCIS (Netherlands)

Huisman, M.C.; van der Molen, S.J.; Vis, R.D.

1999-01-01

Switchable mirrors made of thin films of Y, La or rare-earth (RE) metals exhibit spectacular changes in their optical and electrical properties upon hydrogen loading. The study of these materials has indicated that the occurring phenomena are highly sensitive to the actual hydrogen concentration in

Development of a load cell for mechanical testing in hydrogen

International Nuclear Information System (INIS)

McCabe, L.P.

1982-01-01

Mechanical testing in hydrogen environments is performed on materials to determine hydrogen compatibility. Many tests are performed on small test samples in pressure vessels where monitoring of actual sample load is difficult. A method was developed to monitor small samples by placing inside the vessel a miniature load cell which is capable of measuring loads of less than 100 lbs. The load cell monitors load by means of a Wheatstone Bridge circuit composed of four strain gages. Two of the gages are mounted on a stainless steel stub which becomes part of the vessel load string; the others are wired outside the pressure vessel. Previously, load cells have been short-lived because of hydrogen diffusion into the epoxy-phenolic adhesive used to attach the strain gages to the stub. The use of a flame-sprayed ceramic, however, rather than an organic epoxy to mount the strain gages appears to produce a load cell resistant to the hydrogen test environment

Predicted energy densitites for nickel-hydrogen and silver-hydrogen cells embodying metallic hydrides for hydrogen storage

Science.gov (United States)

Easter, R. W.

1974-01-01

Simplified design concepts were used to estimate gravimetric and volumetric energy densities for metal hydrogen battery cells for assessing the characteristics of cells containing metal hydrides as compared to gaseous storage cells, and for comparing nickel cathode and silver cathode systems. The silver cathode was found to yield superior energy densities in all cases considered. The inclusion of hydride forming materials yields cells with very high volumetric energy densities that also retain gravimetric energy densities nearly as high as those of gaseous storage cells.

Phase transition of DNA-linked gold nanoparticles: Creation of a high concentration of atomic hydrogen in impurity-helium solids

International Nuclear Information System (INIS)

Kiselev, S.I.; Khmelenko, V.V.; Bernard, E.P.; Lee, C.Y.; Lee, D.M.

2003-01-01

The exchange tunneling reactions D+H 2 →HD+H and D+HD→D 2 +H were used to generate high concentrations of atomic hydrogen in impurity-helium solids. The dependence of atom concentration on the content of hydrogen in the injected gas mixture gave a maximum concentration of 7.5x10 17 cm -3 hydrogen atoms for an initial gas ratio H 2 :D 2 :He=1:4:100

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.

Evaluation of methods for monitoring air concentrations of hydrogen sulfide

Directory of Open Access Journals (Sweden)

Katarzyna Janoszka

2013-06-01

Full Text Available The development of different branches of industry and a growing fossil fuels mining results in a considerable emission of by-products. Major air pollutants are: CO, CO₂, SO₂, SO₃, H₂S, nitrogen oxides, as well as compounds of an organic origin. The main aspects of this paper is to review and evaluate methods used for monitoring of hydrogen sulfide in the air. Different instrumental techniques were discussed, electrochemical, chromatographic and spectrophotometric (wet and dry, to select the method most suitable for monitoring low levels of hydrogen sulfide, close to its odor threshold. Based on the literature review the method for H₂S determination in the air, involving absorption in aqueous zinc acetate and reaction with N,N-dimethylo-p-phenylodiamine and FeCl₃, has been selected and preliminary verified. The adopted method allows for routine measurements of low concentration of hydrogen sulfide, close to its odor threshold in workplaces and ambient air. Med Pr 2013;64(3:449–454

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.

Hydrogen sulfide regulates intracellular Ca2+ concentration in endothelial cells from excised rat aorta.

Science.gov (United States)

Moccia, Francesco; Bertoni, Giuseppe; Pla, Alessandra Florio; Dragoni, Silvia; Pupo, Emanuela; Merlino, Annalisa; Mancardi, Daniele; Munaron, Luca; Tanzi, Franco

2011-09-01

Hydrogen sulphide (H2S) is a recently discovered gasotransmitter that may regulate a growing number of endothelial functions, including nitric oxide (NO) release, proliferation, adhesion and migration, which are the key steps of angiogenesis. The mechanism whereby H2S impacts on endothelial physiology is still unclear: however, the aforementioned processes are driven by an increase in intracellular Ca2+ concentration ([Ca2+]i). In the present study, we exploited the excised rat aorta to gain insights into the regulation of [Ca2+]i by H2S within in situ endothelial cells (ECs). Sodium hydrosulphide (NaHS), a H2S donor, caused an elevation in [Ca2+]i, which disappeared in absence of extracellular Ca2+. NaHSinduced Ca2+ inflow was sensitive to high doses of Gd3+, but not BTP-2. Inhibition of the reverse-mode of the Na+-Ca2+ exchanger (NCX), with KB-R7943 or upon removal of extracellular Na+, abrogated the Ca2+ response to NaHS. Moreover, NaHS-elicited Ca2+ entry was significantly reduced by TEA and glybenclamide, which hinted at the involvement of ATP-dependent K+ (KATP) channels. Conversely, NaHS-evoked Ca2+ signal was not affected by the reducing agent, dithiothreitol. Acute addition of NaHS hindered both Ca2+ release and Ca2+ entry induced by ATP, a physiological agonist of ECs. Consistently, inhibition of endogenous H2S synthesis with DL-propargylglycine impaired ATP-induced Ca2+ inflow, whereas it did not affect Ca2+ mobilization. These data provide the first evidence that H2S may stimulate Ca2+ influx into ECs by recruiting the reverse-mode of NCX and KATP channels. In addition, they show that such gasotransmitter may modulate the Ca2+ signals elicited by physiological stimuli in intact endothelium.

Possibility of hydrogen supply by shared residential fuel cell systems for fuel cell vehicles

Directory of Open Access Journals (Sweden)

Ono Yusuke

2017-01-01

Full Text Available Residential polymer electrolyte fuel cells cogeneration systems (residential PEFC systems produce hydrogen from city gas by internal gas-reformer, and generate electricity, the hot water at the same time. From the viewpoint of the operation, it is known that residential PEFC systems do not continuously work but stop for long time, because the systems generate enough hot water for short operation time. In other words, currently residential PEFC systems are dominated by the amount of hot water demand. This study focuses on the idle time of residential PEFC systems. Since their gas-reformers are free, the systems have potential to produce hydrogen during the partial load operations. The authors expect that residential PEFC systems can take a role to supply hydrogen for fuel cell vehicles (FCVs before hydrogen fueling stations are distributed enough. From this perspective, the objective of this study is to evaluate the hydrogen production potential of residential PEFC systems. A residential PEFC system was modeled by the mixed integer linear programming to optimize the operation including hydrogen supply for FCV. The objective function represents annual system cost to be minimized with the constraints of energy balance. It should be noted that the partial load characteristics of the gas-reformer and the fuel cell stack are taken into account to derive the optimal operation. The model was employed to estimate the possible amount of hydrogen supply by a residential PEFC system. The results indicated that the system could satisfy at least hydrogen demand for transportation of 8000 km which is as far as the average annual mileage of a passenger car in Japan. Furthermore, hydrogen production by sharing a residential PEFC system with two households is more effective to reduce primary energy consumption with hydrogen supply for FCV than the case of introducing PEFC in each household.

Rapid Thermal Annealing and Hydrogen Passivation of Polycrystalline Silicon Thin-Film Solar Cells on Low-Temperature Glass

Directory of Open Access Journals (Sweden)

Mason L. Terry

2007-01-01

Full Text Available The changes in open-circuit voltage (Voc, short-circuit current density (Jsc, and internal quantum efficiency (IQE of aLuminum induced crystallization, ion-assisted deposition (ALICIA polycrystalline silicon thin-film solar cells on low-temperature glass substrates due to rapid thermal anneal (RTA treatment and subsequent remote microwave hydrogen plasma passivation (hydrogenation are examined. Voc improvements from 130 mV to 430 mV, Jsc improvements from 1.2 mA/cm2 to 11.3 mA/cm2, and peak IQE improvements from 16% to > 70% are achieved. A 1-second RTA plateau at 1000°C followed by hydrogenation increases the Jsc by a factor of 5.5. Secondary ion mass spectroscopy measurements are used to determine the concentration profiles of dopants, impurities, and hydrogen. Computer modeling based on simulations of the measured IQE data reveals that the minority carrier lifetime in the absorber region increases by 3 orders of magnitude to about 1 nanosecond (corresponding to a diffusion length of at least 1 μm due to RTA and subsequent hydrogenation. The evaluation of the changes in the quantum efficiency and Voc due to RTA and hydrogenation with computer modeling significantly improves the understanding of the limiting factors to cell performance.

Demonstration of Hydrogen Energy Network and Fuel Cells in Residential Homes

International Nuclear Information System (INIS)

Hirohisa Aki; Tetsuhiko Maeda; Itaru Tamura; Akeshi Kegasa; Yoshiro Ishikawa; Ichiro Sugimoto; Itaru Ishii

2006-01-01

The authors proposed the setting up of an energy interchange system by establishing energy networks of electricity, hot water, and hydrogen in residential homes. In such networks, some homes are equipped with fuel cell stacks, fuel processors, hydrogen storage devices, and large storage tanks for hot water. The energy network enables the flexible operation of the fuel cell stacks and fuel processors. A demonstration project has been planned in existing residential homes to evaluate the proposal. The demonstration will be presented in a small apartment building. The building will be renovated and will be equipped with a hydrogen production facility, a hydrogen interchange pipe, and fuel cell stacks with a heat recovery device. The energy flow process from hydrogen production to consumption in the homes will be demonstrated. This paper presents the proposed energy interchange system and demonstration project. (authors)

Hypervelocity Impact Testing of Nickel Hydrogen Battery Cells

Science.gov (United States)

Frate, David T.; Nahra, Henry K.

1996-01-01

Nickel-Hydrogen (Ni/H2) battery cells have been used on several satellites and are planned for use on the International Space Station. In January 1992, the NASA Lewis Research Center (LeRC) conducted hypervelocity impact testing on Ni/H2 cells to characterize their failure modes. The cell's outer construction was a 24 mil-thick Inconel 718 pressure vessel. A sheet of 1.27 cm thick honeycomb was placed in front of the battery cells during testing to simulate the on-orbit box enclosure. Testing was conducted at the NASA White Sands Test Facility (WSTF). The hypervelocity gun used was a 7.6 mm (0.30 caliber) two-stage light gas gun. Test were performed at speeds of 3, 6, and 7 km/sec using aluminum 2017 spherical particles of either 4.8 or 6.4 mm diameter as the projectile. The battery cells were electrically charged to about 75 percent of capacity, then back-filled with hydrogen gas to 900 psi simulating the full charge condition. High speed film at 10,000 frames/sec was taken of the impacts. Impacts in the dome area (top) and the electrode area (middle) of the battery cells were investigated. Five tests on battery cells were performed. The results revealed that in all of the test conditions investigated, the battery cells simply vented their hydrogen gas and some electrolyte, but did not burst or generate any large debris fragments.

The Seebeck coefficient and the Peltier effect in a polymer electrolyte membrane cell with two hydrogen electrodes

International Nuclear Information System (INIS)

Kjelstrup, S.; Vie, P.J.S.; Akyalcin, L.; Zefaniya, P.; Pharoah, J.G.; Burheim, O.S.

2013-01-01

Highlights: • The heat change associated with the hydrogen electrode in a polymer electrolyte cell is determined from Seebeck coefficient measurements. • When electric current is passed from left to right in the outer circuit, the anode becomes warmer, while the cathode becomes colder in a thermoelectric cell with hydrogen electrodes. • At Soret equilibrium for water in the fuel cell, most of the entropy of the fuel cell reaction is generated at the anode. -- Abstract: We report that the Seebeck coefficient of a Nafion membrane cell with hydrogen electrodes saturated with water vapour, at 1 bar hydrogen pressure and 340 K, is equal to 670 ± 50 μV/K, meaning that the entropy change of the anode reaction at reversible conditions (67 J/(K mol)) corresponds to a reversible heat release of 22 kJ/mol. The transported entropy of protons across the membrane at Soret equilibrium was estimated from this value to 1 ± 5 J/(K mol). The results were supported by the expected variation in the Seebeck coefficient with the hydrogen pressure. We report also the temperature difference of the electrodes, when passing electric current through the cell, and find that the anode is heated (a Peltier heat effect), giving qualitative support to the result for the Seebeck coefficient. The Seebeck and Peltier effects are related by non-equilibrium thermodynamics theory, and the Peltier heat of the cathode in the fuel cell is calculated for steady state conditions to 6 ± 2 kJ/mol at 340 K. The division of the reversible heat release between the anode and the cathode, can be expected to vary with the current density, as the magnitude of the current density can have a big impact on water transport and water concentration profile

The National Center For Hydrogen And Fuel Cells. Jump-starting the hydrogen economy through research

International Nuclear Information System (INIS)

Stefanescu, Ioan; Varlam, Mihai; Carcadea, Elena

2010-01-01

Full text: The research, design and implementation of hydrogen-based economy must consider each of the segments of the hydrogen energy system - production, supply, storage, conversion. The National Center for Hydrogen and Fuel Cells has the experience, expertise, facilities and instrumentation necessary to have a key role in developing any aspect of hydrogen-based economy, aiming to integrate technologies for producing and using hydrogen as an 'energy vector'. This paper presents a simulation of the applied 'learning curve' concept, NCHFC being the key element of R and D in the field in comparing the costs involved. It also presents the short and medium term research program of NCHFC, the main research and development directions being specified. (authors)

Hydrogen and fuel cell activity report, France 2009

International Nuclear Information System (INIS)

2009-01-01

This report gathers the main highlights of 2009 in the field of hydrogen and fuel cells in France. It presents the political context (priority to a sustainable development and to renewable energies) and the main initiatives (official commitment, projects and programmes launched by different public bodies and organizations). It briefly presents the projects and programmes concerning the hydrogen: ANR programmes, national structures dedicated to hydrogen and fuel cells, fundamental research, demonstrator project (the H2E project), applications in transport (a project by Peugeot, the Althytude project coordinated by GDF, the Hychain European project, and other airborne or maritime projects), stationary applications (MYRTE). It also briefly describes the activities of some small companies (CETH, McPHY, RAIGI, PRAGMA Industries, N-GHY, SAGIM), and regional initiatives. Colloquiums, congresses and meetings are mentioned

Comparison of ammonia and methanol applied indirectly in a hydrogen fuel cell

International Nuclear Information System (INIS)

Metkemeijer, R.; Achard, P.

1993-01-01

A comparison is presented between ammonia and methanol, applied indirectly in a hydrogen/air fuel cell. The calculations concentrate on specific energy of the fuels (amount of electricity produced per mass of fuel), specific energy of the fuels corrected for the mass and volume of the tank, and the overall energy efficiency (amount of electricity produced by one kg of fuel divided by the amount of energy needed for the production of one kg of this fuel). Taking into consideration the differences in efficiencies between the acid fuel cell and the alkaline fuel cells, the reformer temperatures, the reforming efficiencies, and some ecological and economical considerations, it appears that ammonia is a more interesting fuel than methanol for certain applications. 6 figs., 2 tabs

2013 Annual Progress Report: DOE Hydrogen and Fuel Cells Program

Energy Technology Data Exchange (ETDEWEB)

none,

2013-12-01

The 2013 Annual Progress Report summarizes fiscal year 2013 activities and accomplishments by projects funded by the DOE Hydrogen Program. It covers the program areas of hydrogen production and delivery; hydrogen storage; fuel cells; manufacturing; technology validation; safety, codes and standards; market transformation; and systems analysis.

2014 Annual Progress Report: DOE Hydrogen and Fuel Cells Program

Energy Technology Data Exchange (ETDEWEB)

none,

2014-11-01

The 2014 Annual Progress Report summarizes fiscal year 2014 activities and accomplishments by projects funded by the DOE Hydrogen Program. It covers the program areas of hydrogen production and delivery; hydrogen storage; fuel cells; manufacturing; technology validation; safety, codes and standards; market transformation; and systems analysis.

2011 Annual Progress Report: DOE Hydrogen and Fuel Cells Program

Energy Technology Data Exchange (ETDEWEB)

Satyapal, Sunita [Office of Energy Efficiency and Renewable Energy (EERE), Washington, DC (United States)

2011-11-01

The 2011 Annual Progress Report summarizes fiscal year 2011 activities and accomplishments by projects funded by the DOE Hydrogen Program. It covers the program areas of hydrogen production and delivery; hydrogen storage; fuel cells; manufacturing; technology validation; safety, codes and standards; education; market transformation; and systems analysis.

Low concentrations of doxycycline attenuates FasL-induced apoptosis in HeLa cells.

Science.gov (United States)

Yoon, Jung Mi; Koppula, Sushruta; Huh, Se Jong; Hur, Sun Jin; Kim, Chan Gil

2015-07-24

Doxycycline (DC) has been shown to possess non-antibiotic properties including Fas/Fas Ligand (FasL)-mediated apoptosis against several tumor types in the concentration range of 10-40 µg/mL. However, the effect of DC in apoptotic signaling at much low concentrations was not studied. The present study investigated the attenuation effect of low dose of DC on FasL-induced apoptosis in HeLa cell by the methods of MTT assay, fluorescence microscopy, DNA fragmentation, flow cytometry analysis, and western blotting. In the present findings we showed that low concentration of DC (HeLa cells. FasL treatment to HeLa cells resulted in a concentration-dependent induction of cell death, and treatment with low concentrations of DC (0.1-2 µg/mL) significantly (p cell death as measured by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Further, the FasL-induced apoptotic features in HeLa cells, such as morphological changes, DNA fragmentation and cell cycle arrest was also inhibited by DC (0.5 µg/mL). Tetracycline and minocycline also showed similar anti-apoptotic effects but were not significant when compared to DC, tested at same concentrations. Further, DC (0.01-16 µg/mL) did not influence the hydrogen peroxide- or cisplatin-induced intrinsic apoptotic pathway in HeLa cells. Protein analysis using Western blotting confirmed that FasL-induced cleavage/activation of caspase-8 and caspase-3, were inhibited by DC treatment at low concentration (0.5 µg/mL). Considering the overall data, we report for the first time that DC exhibited anti-apoptotic effects at low concentrations in HeLa cells by inhibition of caspase activation via FasL-induced extrinsic pathway.

Hydrogen inhalation ameliorated mast cell mediated brain injury after ICH in mice

Science.gov (United States)

Manaenko, Anatol; Lekic, Tim; Ma, Qingyi; Zhang, John H.; Tang, Jiping

2012-01-01

OBJECTIVE Hydrogen inhalation was neuroprotective in several brain injury models. Its mechanisms are believed to be related to anti-oxidative stress. We investigated the potential neurovascular protective effect of hydrogen inhalation especially effect on mast cell activation in a mouse model of intracerebral hemorrhage (ICH). DESIGN Controlled in vivo laboratory study. SETTING Animal research laboratory SUBJECTS 171, 8 weeks old male CD-1 mice were used. INTERVENTIONS Collagenase-induced ICH model in 8 weeks old, male, CD-1 mice was used. Hydrogen was administrated via spontaneous inhalation. The blood-brain barrier (BBB) permeability and neurological deficits were investigated at 24 and 72 hours after ICH. Mast cell activation was evaluated by Western blot and immuno-staining. The effects of hydrogen inhalation on mast cell activation were confirmed in an autologous blood injection model ICH. MEASURMENT AND MAIN RESULTS At 24 and 72 hours post-ICH, animals showed BBB disruption, brain edema, neurological deficits, accompanied with phosphorylation of Lyn kinase and release of tryptase, indicating mast cell activation. Hydrogen treatment diminished phosphorylation of Lyn kinase and release of tryptase, decreased accumulation and degranulation of mast cells, attenuated BBB disruption and improved neurobehavioral function. CONCLUSION Activation of mast cells following ICH contributed to increase of BBB permeability and brain edema. Hydrogen inhalation preserved BBB disruption by prevention of mast cell activation after ICH. PMID:23388512

Effects of vitamin C, vitamin E, and molecular hydrogen on the placental function in trophoblast cells.

Science.gov (United States)

Guan, Zhong; Li, Huai-Fang; Guo, Li-Li; Yang, Xiang

2015-08-01

This study aimed to investigate the effects of three different antioxidants, namely vitamin C, vitamin E, and molecular hydrogen, on cytotrophoblasts in vitro. Two trophoblast cell lines, JAR and JEG-3, were exposed to different concentrations of vitamin C (0, 25, 50, 100, 500, 1,000, 5,000 μmol/L), vitamin E (0, 25, 50, 100, 500, 1,000, 5,000 μmol/L), and molecular hydrogen (0, 25, 50, 100, 500 μmol/L) for 48 h. The cell viability was detected using the MTS assay. The secretion of human chorionic gonadotropin (hCG) and the tumor necrosis factor-α (TNF-α) were assessed and the expression of TNF-α mRNA was observed by real-time RT-PCR. Cell viability was significantly suppressed by 500 μmol/L vitamins C and E (P 0.05). The expression of TNF-α was increased by 100 μmol/L vitamin C and 50 μmol/L vitamins E, separately or combined (P vitamin C and E, separately or combined. High levels of antioxidant vitamins C and E may have significant detrimental effects on placental function, as reflected by decreased cell viability and secretion of hCG; and placental immunity, as reflected by increased production of TNF-a. Meanwhile hydrogen showed no such effects on cell proliferation and TNF-α expression, but it could affect the level of hCG, indicating hydrogen as a potential candidate of antioxidant in the management of preeclampsia (PE) should be further studied.

The developments of international hydrogen and fuel cell technology standards and the response strategies in Taiwan

International Nuclear Information System (INIS)

Tso, C.

2009-01-01

The application of hydrogen and fuel cells has expanded as the technology in international markets has improved. Leading countries have focused on establishing hydrogen and fuel cell technology standards. Both the International Organization for Standardization (ISO) and the International Electrotechnical Commission (IEC) continuously release new hydrogen and fuel cell related standards. Although the government of Taiwan is promoting the development of a hydrogen and fuel cell industry, it may delay the commercialized schedule if there are no hydrogen and fuel cell related standards and regulations in place. Standards and regulations must be established as quickly as possible in order to accelerate the progress of the hydrogen and fuel cell industry. This presentation reviewed the international progress in hydrogen and fuel cell development and explained Taiwan's response strategies regarding the adoption of hydrogen and fuel cell products in niche Taiwanese markets

Challenge for lowering concentration polarization in solid oxide fuel cells

Science.gov (United States)

Shimada, Hiroyuki; Suzuki, Toshio; Yamaguchi, Toshiaki; Sumi, Hirofumi; Hamamoto, Koichi; Fujishiro, Yoshinobu

2016-01-01

In the scope of electrochemical phenomena, concentration polarization at electrodes is theoretically inevitable, and lowering the concentration overpotential to improve the performance of electrochemical cells has been a continuing challenge. Electrodes with highly controlled microstructure, i.e., high porosity and uniform large pores are therefore essential to achieve high performance electrochemical cells. In this study, state-of-the-art technology for controlling the microstructure of electrodes has been developed for realizing high performance support electrodes of solid oxide fuel cells (SOFCs). The key is controlling the porosity and pore size distribution to improve gas diffusion, while maintaining the integrity of the electrolyte and the structural strength of actual sized electrode supports needed for the target application. Planar anode-supported SOFCs developed in this study realize 5 μm thick dense electrolyte (yttria-stabilized zirconia: YSZ) and the anode substrate (Ni-YSZ) of 53.6 vol.% porosity with a large median pore diameter of 0.911 μm. Electrochemical measurements reveal that the performance of the anode-supported SOFCs improves with increasing anode porosity. This Ni-YSZ anode minimizes the concentration polarization, resulting in a maximum power density of 3.09 W cm-2 at 800 °C using humidified hydrogen fuel without any electrode functional layers.

Multiple cell common pressure vessel nickel hydrogen battery

Science.gov (United States)

Zagrodnik, Jeffrey P.; Jones, Kenneth R.

1991-01-01

A multiple cell common pressure vessel (CPV) nickel hydrogen battery was developed that offers significant weight, volume, cost, and interfacing advantages over the conventional individual pressure vessel (IPV) nickel hydrogen configuration that is currently used for aerospace applications. The baseline CPV design was successfully demonstrated though the testing of a 26 cell prototype, which completed over 7,000 44 percent depth of discharge LEO cycles. Two-cell boilerplate batteries have now exceeded 12,500 LEO cycles in ongoing laboratory tests. CPV batteries using both nominal 5 and 10 inch diameter vessels are currently available. The flexibility of the design allows these diameters to provide a broad capability for a variety of space applications.

Solar Hydrogen Fuel Cell Projects at Brooklyn Tech

Science.gov (United States)

Fedotov, Alex; Farah, Shadia; Farley, Daithi; Ghani, Naureen; Kuo, Emmy; Aponte, Cecielo; Abrescia, Leo; Kwan, Laiyee; Khan, Ussamah; Khizner, Felix; Yam, Anthony; Sakeeb, Khan; Grey, Daniel; Anika, Zarin; Issa, Fouad; Boussayoud, Chayama; Abdeldayem, Mahmoud; Zhang, Alvin; Chen, Kelin; Chan, Kameron Chuen; Roytman, Viktor; Yee, Michael

2010-01-01

This article describes the projects on solar hydrogen powered vehicles using water as fuel conducted by teams at Brooklyn Technical High School. Their investigations into the pure and applied chemical thermodynamics of hydrogen fuel cells and bio-inspired devices have been consolidated in a new and emerging sub-discipline that they define as solar…

Hydrogen as a fuel for fuel cell vehicles: A technical and economic comparison

Energy Technology Data Exchange (ETDEWEB)

Ogden, J.; Steinbugler, M.; Kreutz, T. [Princeton Univ., NJ (United States). Center for Energy and Environmental Studies

1997-12-31

All fuel cells currently being developed for near term use in vehicles require hydrogen as a fuel. Hydrogen can be stored directly or produced onboard the vehicle by reforming methanol, ethanol or hydrocarbon fuels derived from crude oil (e.g., Diesel, gasoline or middle distillates). The vehicle design is simpler with direct hydrogen storage, but requires developing a more complex refueling infrastructure. In this paper, the authors compare three leading options for fuel storage onboard fuel cell vehicles: compressed gas hydrogen storage; onboard steam reforming of methanol; onboard partial oxidation (POX) of hydrocarbon fuels derived from crude oil. Equilibrium, kinetic and heat integrated system (ASPEN) models have been developed to estimate the performance of onboard steam reforming and POX fuel processors. These results have been incorporated into a fuel cell vehicle model, allowing us to compare the vehicle performance, fuel economy, weight, and cost for various fuel storage choices and driving cycles. A range of technical and economic parameters were considered. The infrastructure requirements are also compared for gaseous hydrogen, methanol and hydrocarbon fuels from crude oil, including the added costs of fuel production, storage, distribution and refueling stations. Considering both vehicle and infrastructure issues, the authors compare hydrogen to other fuel cell vehicle fuels. Technical and economic goals for fuel cell vehicle and hydrogen technologies are discussed. Potential roles for hydrogen in the commercialization of fuel cell vehicles are sketched.

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

The Australian Hydrogen and Fuel Cells Education Program

International Nuclear Information System (INIS)

Luigi Bonadio

2006-01-01

The next generation of engineers and scientists will face great technical, economic and political challenges to satisfy increasing demands for a secure, reliable and affordable global energy system that maintains and enhances current standards of living. The Australian Hydrogen and Fuel Cells Education Program aims to bolster the quality and relevance of primary and secondary school teaching in emerging areas of science, technology and environmental/sustainability studies using hydrogen, in its capacity as a versatile energy carrier, as the educational basis for teacher and student learning. Critical advances in specific areas of hydrogen production, distribution, storage and end-use technologies arise when students are engaged to develop and apply a broad range of disciplinary and interdisciplinary knowledge and practical skills. A comprehensive hydrogen and fuel cell technology teaching module will be developed to complement existing fuels and energy curricula across Australian schools. The pilot program will be delivered via the collaboration of nine trial schools, a broad range of technical and pedagogy experts and representatives of professional bodies and industry. The program features essential and extensive teacher consultation, a professional learning and development course, industry site visits and a dedicated research and evaluation study. This initiative aims to bolster teacher literacy and student participation in the design, construction and operation of various hydrogen and fuel cell devices and extended activities. Students will reflect on and formally present their learning experiences via several dedicated fora including an awards ceremony where outstanding performance of leading schools, teachers and student groups within the cluster will be acknowledged. (authors)

The Australian Hydrogen and Fuel Cells Education Program

Energy Technology Data Exchange (ETDEWEB)

Luigi Bonadio [Senior Consultant Luigi Bonadio and Associates (Australia)

2006-07-01

The next generation of engineers and scientists will face great technical, economic and political challenges to satisfy increasing demands for a secure, reliable and affordable global energy system that maintains and enhances current standards of living. The Australian Hydrogen and Fuel Cells Education Program aims to bolster the quality and relevance of primary and secondary school teaching in emerging areas of science, technology and environmental/sustainability studies using hydrogen, in its capacity as a versatile energy carrier, as the educational basis for teacher and student learning. Critical advances in specific areas of hydrogen production, distribution, storage and end-use technologies arise when students are engaged to develop and apply a broad range of disciplinary and interdisciplinary knowledge and practical skills. A comprehensive hydrogen and fuel cell technology teaching module will be developed to complement existing fuels and energy curricula across Australian schools. The pilot program will be delivered via the collaboration of nine trial schools, a broad range of technical and pedagogy experts and representatives of professional bodies and industry. The program features essential and extensive teacher consultation, a professional learning and development course, industry site visits and a dedicated research and evaluation study. This initiative aims to bolster teacher literacy and student participation in the design, construction and operation of various hydrogen and fuel cell devices and extended activities. Students will reflect on and formally present their learning experiences via several dedicated fora including an awards ceremony where outstanding performance of leading schools, teachers and student groups within the cluster will be acknowledged. (authors)

Effects of Low Phytanic Acid-Concentrated DHA on Activated Microglial Cells: Comparison with a Standard Phytanic Acid-Concentrated DHA.

Science.gov (United States)

Ruiz-Roso, María Belén; Olivares-Álvaro, Elena; Quintela, José Carlos; Ballesteros, Sandra; Espinosa-Parrilla, Juan F; Ruiz-Roso, Baltasar; Lahera, Vicente; de Las Heras, Natalia; Martín-Fernández, Beatriz

2018-05-30

Docosahexaenoic acid (DHA, 22:6 n-3) is an essential omega-3 (ω-3) long chain polyunsaturated fatty acid of neuronal membranes involved in normal growth, development, and function. DHA has been proposed to reduce deleterious effects in neurodegenerative processes. Even though, some inconsistencies in findings from clinical and pre-clinical studies with DHA could be attributed to the presence of phytanic acid (PhA) in standard DHA treatments. Thus, the aim of our study was to analyze and compare the effects of a low PhA-concentrated DHA with a standard PhA-concentrated DHA under different neurotoxic conditions in BV-2 activated microglial cells. To this end, mouse microglial BV-2 cells were stimulated with either lipopolysaccharide (LPS) or hydrogen peroxide (H 2 O 2 ) and co-incubated with DHA 50 ppm of PhA (DHA (PhA:50)) or DHA 500 ppm of PhA (DHA (PhA:500)). Cell viability, superoxide anion (O 2 - ) production, Interleukin 6 (L-6), cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS), glutathione peroxidase (GtPx), glutathione reductase (GtRd), Caspase-3, and the brain-derived neurotrophic factor (BDNF) protein expression were explored. Low PhA-concentrated DHA protected against LPS or H 2 O 2 -induced cell viability reduction in BV-2 activated cells and O 2 - production reduction compared to DHA (PhA:500). Low PhA-concentrated DHA also decreased COX-2, IL-6, iNOS, GtPx, GtRd, and SOD-1 protein expression when compared to DHA (PhA:500). Furthermore, low PhA-concentrated DHA increased BDNF protein expression in comparison to DHA (PhA:500). The study provides data supporting the beneficial effect of low PhA-concentrated DHA in neurotoxic injury when compared to a standard PhA-concentrated DHA in activated microglia.

Improved performance in GaInNAs solar cells by hydrogen passivation

International Nuclear Information System (INIS)

Fukuda, M.; Whiteside, V. R.; Keay, J. C.; Meleco, A.; Sellers, I. R.; Hossain, K.; Golding, T. D.; Leroux, M.; Al Khalfioui, M.

2015-01-01

The effect of UV-activated hydrogenation on the performance of GaInNAs solar cells is presented. A proof-of-principle investigation was performed on non-optimum GaInNAs cells, which allowed a clearer investigation of the role of passivation on the intrinsic nitrogen-related defects in these materials. Upon optimized hydrogenation of GaInNAs, a significant reduction in the presence of defect and impurity based luminescence is observed as compared to that of unpassivated reference material. This improvement in the optical properties is directly transferred to an improved performance in solar cell operation, with a more than two-fold improvement in the external quantum efficiency and short circuit current density upon hydrogenation. Temperature dependent photovoltaic measurements indicate a strong contribution of carrier localization and detrapping processes, with non-radiative processes dominating in the reference materials, and evidence for additional strong radiative losses in the hydrogenated solar cells

Towards a greener world : hydrogen and fuel cells 2004 conference and trade show. Conference proceedings

International Nuclear Information System (INIS)

2004-01-01

Fuel Cells Canada and the Canadian Hydrogen Association hosted the Hydrogen and Fuel Cells 2004 Conference and Tradeshow in Toronto, Ontario, Canada on September 25-28, 2004. Industry leaders from around the world showcased the latest developments in fuel cell and hydrogen technology, and shared research breakthroughs. The conference focussed on many aspects of hydrogen and fuel cell technology, specifically: hydrogen technology progress, including storage, infrastructure and production; fuel cells, including quality, cost and applications; economics and policy, including government and industry strategies; fuel cell demonstrations, including transportation, micro-fuel cells, and portable power; and, impact on climate change, including health and the Kyoto Accord

A Microfluidic Cell Concentrator

Science.gov (United States)

Warrick, Jay; Casavant, Ben; Frisk, Megan; Beebe, David

2010-01-01

Cell concentration via centrifugation is a ubiquitous step in many cell culture procedures. At the macroscale, centrifugation suffers from a number of limitations particularly when dealing with small numbers of cells (e.g., less than 50,000). On the other hand, typical microscale methods for cell concentration can affect cell physiology and bias readouts of cell behavior and function. In this paper, we present a microfluidic concentrator device that utilizes the effects of gravity to allow cells to gently settle out of a suspension into a collection region without the use of specific adhesion ligands. Dimensional analysis was performed to compare different device designs and was verified with flow modeling to optimize operational parameters. We are able to concentrate low-density cell suspensions in a microfluidic chamber, achieving a cell loss of only 1.1 ± 0.6% (SD, n=7) with no observed loss during a subsequent cell staining protocol which incorporates ~36 complete device volume replacements. This method provides a much needed interface between rare cell samples and microfluidic culture assays. PMID:20843010

Storing Hydrogen, by Enhancing Diamond Powder Properties under Hydrogen Plasma with CaF2 and KF for Use in Fuel Cells

International Nuclear Information System (INIS)

Ochoa, Franklyn E. Colmenares

2006-01-01

A fuel cell is like a battery that instead of using electricity to recharge itself, it uses hydrogen. In the fuel cell industry, one of the main problems is storing hydrogen in a safe way and extracting it economically. Gaseous hydrogen requires high pressures which could be very dangerous in case of a collision. The success of hydrogen use depends largely on the development of an efficient storage and release method. In an effort to develop a better hydrogen storage system for fuel cells technology this research investigates the use of 99% pure diamond powder for storing hydrogen. Mixing this powder with a calcium fluoride and potassium fluoride compound in its solid form and treating the surface of the powder with hydrogen plasma, modifies the surface of the diamond. After some filtration through distilled water and drying, the modified diamond is treated with hydrogen. We expect hydrogen to be attracted to the diamond powder surface in higher quantities due to the CaF2 and KF treatment. Due to the large surface area of diamond nanopowder and the electronegative terminal bonds of the fluorine particles on the structure's surface, to the method shows promise in storing high densities of hydrogen

Salicylic acid induces apoptosis in colon carcinoma cells grown in-vitro: Influence of oxygen and salicylic acid concentration

Energy Technology Data Exchange (ETDEWEB)

Zitta, Karina; Meybohm, Patrick; Bein, Berthold; Huang, Ying; Heinrich, Christin; Scholz, Jens; Steinfath, Markus; Albrecht, Martin, E-mail: Albrecht@anaesthesie.uni-kiel.de

2012-04-15

In solid tumors the hypoxic environment can promote tumor progression and resistance to therapy. Recently, acetylsalicylic acid a major component of analgesic drugs and its metabolite salicylic acid (SA) have been shown to reduce the risk of colon cancer, but the mechanisms of action remain still unclear. Here we elucidate the effects of physiologically relevant concentrations of SA on colon carcinoma cells (CaCo-2) grown under normoxic and hypoxic conditions. Western blotting, caspase-3/7 apoptosis assays, MTS cell-proliferation assays, LDH cytotoxicity assays and hydrogen peroxide measurements were performed to investigate the effects of 1 and 10 {mu}M SA on CaCo-2 cells grown under normoxic conditions and cells exposed to hypoxia. Under normoxic conditions, SA did not influence cell proliferation or LDH release of CaCo-2 cells. However, caspase-3/7 activity was significantly increased. Under hypoxia, cell proliferation was reduced and LDH release and caspase-3/7 activities were increased. None of these parameters was altered by the addition of SA under hypoxic conditions. Hypoxia increased hydrogen peroxide concentrations 300-fold and SA significantly augmented the release of hydrogen peroxide under normoxic, but not under hypoxic conditions. Phosphorylation of the pro-survival kinases akt and erk1/2 was not changed by SA under hypoxic conditions, whereas under normoxia SA reduced phosphorylation of erk1/2 after 2 hours. We conclude that in colon carcinoma cells effects of SA on apoptosis and cellular signaling are dependent on the availability of oxygen. -- Highlights: Black-Right-Pointing-Pointer Effects of salicylic acid on colon carcinoma cells grown under normoxic and hypoxic conditions Black-Right-Pointing-Pointer Salicylic acid increases caspase-3/7 activity and hydrogen peroxide release under normoxia Black-Right-Pointing-Pointer Salicylic acid decreases pro-survival erk-1/2 phosphorylation under normoxia Black-Right-Pointing-Pointer Salicylic acid does

Quantifying intracellular hydrogen peroxide perturbations in terms of concentration

Directory of Open Access Journals (Sweden)

Beijing K. Huang

2014-01-01

Full Text Available Molecular level, mechanistic understanding of the roles of reactive oxygen species (ROS in a variety of pathological conditions is hindered by the difficulties associated with determining the concentration of various ROS species. Here, we present an approach that converts fold-change in the signal from an intracellular sensor of hydrogen peroxide into changes in absolute concentration. The method uses extracellular additions of peroxide and an improved biochemical measurement of the gradient between extracellular and intracellular peroxide concentrations to calibrate the intracellular sensor. By measuring peroxiredoxin activity, we found that this gradient is 650-fold rather than the 7–10-fold that is widely cited. The resulting calibration is important for understanding the mass-action kinetics of complex networks of redox reactions, and it enables meaningful characterization and comparison of outputs from endogenous peroxide generating tools and therapeutics across studies.

Making the case for direct hydrogen storage in fuel cell vehicles

Energy Technology Data Exchange (ETDEWEB)

James, B.D.; Thomas, C.E.; Baum, G.N.; Lomas, F.D. Jr.; Kuhn, I.F. Jr. [Directed Technologies, Inc., Arlington, VA (United States)

1997-12-31

Three obstacles to the introduction of direct hydrogen fuel cell vehicles are often states: (1) inadequate onboard hydrogen storage leading to limited vehicle range; (2) lack of an hydrogen infrastructure, and (3) cost of the entire fuel cell system. This paper will address the first point with analysis of the problem/proposed solutions for the remaining two obstacles addressed in other papers. Results of a recent study conducted by Directed Technologies Inc. will be briefly presented. The study, as part of Ford Motor Company/DOE PEM Fuel Cell Program, examines multiple pure hydrogen onboard storage systems on the basis of weight, volume, cost, and complexity. Compressed gas, liquid, carbon adsorption, and metal hydride storage are all examined with compressed hydrogen storage at 5,000 psia being judged the lowest-risk, highest benefit, near-term option. These results are combined with recent fuel cell vehicle drive cycle simulations to estimate the onboard hydrogen storage requirement for full vehicle range (380 miles on the combined Federal driving schedule). The results indicate that a PNGV-like vehicle using powertrain weights and performance realistically available by the 2004 PNGV target data can achieve approximate fuel economy equivalent to 100 mpg on gasoline (100 mpg{sub eq}) and requires storage of approximately 3.6 kg hydrogen for full vehicle storage quantity allows 5,000 psia onboard storage without altering the vehicle exterior lines or appreciably encroaching on the passenger or trunk compartments.

High-rate fermentative hydrogen production from beverage wastewater

International Nuclear Information System (INIS)

Sivagurunathan, Periyasamy; Sen, Biswarup; Lin, Chiu-Yue

2015-01-01

Highlights: • Hybrid immobilized-bacterial cells show stable operation over 175 days. • Low HRT of 1.5 h shows peak hydrogen production rate of 55 L/L-d. • Electricity generation is 9024 kW-d from 55 L/L-d hydrogen using beverage wastewater. • Granular sludge formed only at 2–3 h HRT with presence of Selenomonas sp. - Abstract: Hydrogen production from beverage industry wastewater (20 g/L hexose equivalent ) using an immobilized cell reactor with a continuous mode of operation was studied at various hydraulic retention times (HRT, 8–1.5 h). Maximum hydrogen production rate (HPR) of 55 L/L-d was obtained at HRT 1.5 h (an organic loading of 320 g/L-d hexose equivalent ). This HPR value is much higher than those of other industrial wastewaters employed in fermentative hydrogen production. The cell biomass concentration peaked at 3 h HRT with a volatile suspended solids (VSS) concentration of 6.31 g/L (with presence of self-flocculating Selenomonas sp.), but it dropped to 3.54 gVSS/L at 1.5 h HRT. With the shortening of HRT, lactate concentration increased but the concentration of the dominant metabolite butyrate did not vary significantly. The Clostridium species dynamics was not significantly affected, but total microbial community structure changed with respect to HRT variation as evident from PCR–DGGE analyses. Analysis of energy production rate suggests that beverage wastewater is a high energy yielding feedstock, and can replace 24% of electricity consumption in a model beverage industry

Concentration of atomic hydrogen in a dielectric barrier discharge measured by two-photon absorption fluorescence

Science.gov (United States)

Dvořák, P.; Talába, M.; Obrusník, A.; Kratzer, J.; Dědina, J.

2017-08-01

Two-photon absorption laser-induced fluorescence (TALIF) was utilized for measuring the concentration of atomic hydrogen in a volume dielectric barrier discharge (DBD) ignited in mixtures of Ar, H2 and O2 at atmospheric pressure. The method was calibrated by TALIF of krypton diluted in argon at atmospheric pressure, proving that three-body collisions had a negligible effect on quenching of excited krypton atoms. The diagnostic study was complemented with a 3D numerical model of the gas flow and a zero-dimensional model of the chemistry in order to better understand the reaction kinetics and identify the key pathways leading to the production and destruction of atomic hydrogen. It was determined that the density of atomic hydrogen in Ar-H2 mixtures was in the order of 1021 m-3 and decreased when oxygen was added into the gas mixture. Spatially resolved measurements and simulations revealed a sharply bordered region with low atomic hydrogen concentration when oxygen was added to the gas mixture. At substoichiometric oxygen/hydrogen ratios, this H-poor region is confined to an area close to the gas inlet and it is shown that the size of this region is not only influenced by the chemistry but also by the gas flow patterns. Experimentally, it was observed that a decrease in H2 concentration in the feeding Ar-H2 mixture led to an increase in H production in the DBD.

Measure of hydrogen concentration profile in materials by resonant nuclear reactions

International Nuclear Information System (INIS)

Livi, R.P.; Zawislak, F.C.; Acquadro, J.C.

1986-01-01

The technique for determining the profile of hydrogen concentration in proximities of the surface of materials, is presented. The preliminary measurements were done, using the Pelletron accelerator at Sao Paulo University (USP), in Brazil, for the resonant-nuclear reaction 1 H( 19 F, α γ) 16 O. By using this reaction the technique is sensitive for concentrations above 500 ppm, which could be reduced to 100 ppm through special shieldings and other techniques to reduce the background radiation. (M.C.K.) [pt

Submersed sensing electrode used in fuel-cell type hydrogen detector

Science.gov (United States)

Niedrach, L. W.; Rudek, F. P.; Rutkoneski, M. D.

1971-01-01

Electrode has silicone rubber diffusion barrier with fixed permeation constant for hydrogen. Barrier controls flow of hydrogen to anode and Faraday relationship establishes upper limit for current through cell. Electrode fabrication is described.

Impact of contamination on hydrogenated amorphous silicon thin films and solar cells

Energy Technology Data Exchange (ETDEWEB)

Woerdenweber, Jan

2011-09-26

This thesis deals with atmospheric contamination and cross-contamination of boron (single-chamber process) of the intrinsic absorber layer (i-layer) of p-i-n thin film solar cells based on hydrogenated amorphous silicon. The atmospheric contaminations were introduced by means of intentional leaks. Hereby, the focus is on the influence of contamination species (oxygen and nitrogen), quantity of contamination (leak flow), source of contamination (leaks at chamber wall or in the process gas pipe), and plasma power on the properties of solar cells. Thereby, the minimum requirements for the purity of vacuum and process gas as well as leak conditions of the recipient and gas pipe system have been determined. Additionally, deposition regimes were developed, where the incorporation of impurities is significantly suppressed. For standard processes critical levels of nitrogen and oxygen contamination are determined to be {proportional_to} 4 x 10{sup 18} cm{sup -3} and {proportional_to} 2 x 10{sup 19} cm{sup -3}, respectively, for a leak situated at the chamber wall. Above these concentrations the solar cell efficiency deteriorates. In literature, incorporation of oxygen and nitrogen in doping configuration is assumed to be the reason for the cell deterioration. This assumption is supported by additional material studies of contaminated absorber layers done in this work. The difference in critical concentration is due to the higher doping efficiency of nitrogen compared to that for oxygen. Nevertheless, applying an air leak the critical concentrations of O and N are reached almost simultaneously since the incorporation probability of oxygen is about one order of magnitude higher compared to that for nitrogen. Applying a leak in the process gas pipe the critical oxygen contamination level increases to {proportional_to} 2 x 10{sup 20} cm{sup -3} whereas the critical nitrogen level remains unchanged compared to a chamber wall leak. Applying a deposition regime with a very high

Hydrogen Fuel Cells: Part of the Solution

Science.gov (United States)

Busby, Joe R.; Altork, Linh Nguyen

2010-01-01

With the decreasing availability of oil and the perpetual dependence on foreign-controlled resources, many people around the world are beginning to insist on alternative fuel sources. Hydrogen fuel cell technology is one answer to this demand. Although modern fuel cell technology has existed for over a century, the technology is only now becoming…

Assessment of hydrogen fuel cell applications using fuzzy multiple-criteria decision making method

International Nuclear Information System (INIS)

Chang, Pao-Long; Hsu, Chiung-Wen; Lin, Chiu-Yue

2012-01-01

Highlights: ► This study uses the fuzzy MCDM method to assess hydrogen fuel cell applications. ► We evaluate seven different hydrogen fuel cell applications based on 14 criteria. ► Results show that fuel cell backup power systems should be chosen for development in Taiwan. -- Abstract: Assessment is an essential process in framing government policy. It is critical to select the appropriate targets to meet the needs of national development. This study aimed to develop an assessment model for evaluating hydrogen fuel cell applications and thus provide a screening tool for decision makers. This model operates by selecting evaluation criteria, determining criteria weights, and assessing the performance of hydrogen fuel cell applications for each criterion. The fuzzy multiple-criteria decision making method was used to select the criteria and the preferred hydrogen fuel cell products based on information collected from a group of experts. Survey questionnaires were distributed to collect opinions from experts in different fields. After the survey, the criteria weights and a ranking of alternatives were obtained. The study first defined the evaluation criteria in terms of the stakeholders, so that comprehensive influence criteria could be identified. These criteria were then classified as environmental, technological, economic, or social to indicate the purpose of each criterion in the assessment process. The selected criteria included 14 indicators, such as energy efficiency and CO 2 emissions, as well as seven hydrogen fuel cell applications, such as forklifts and backup power systems. The results show that fuel cell backup power systems rank the highest, followed by household fuel cell electric-heat composite systems. The model provides a screening tool for decision makers to select hydrogen-related applications.

Multiple cell CPV nickel-hydrogen battery

Science.gov (United States)

Jones, Ken R.; Zagrodnik, Jeffrey P.

1991-01-01

Johnson Controls, Inc. has developed a multiple cell CPV nickel hydrogen battery that offers significant weight, volume, and cost advantages for aerospace applications. The baseline design was successfully demonstrated through the testing of a 26-cell prototype, which completed over 7000 44 percent depth-of-discharge low earth orbit cycles. Prototype designs using both nominal 5 and 10 inch diameter vessels are currently being developed for a variety of customers and applications.

78 FR 18578 - Hydrogen and Fuel Cell Technical Advisory Committee (HTAC)

Science.gov (United States)

2013-03-27

... DEPARTMENT OF ENERGY Office of Energy Efficiency and Renewable Energy Hydrogen and Fuel Cell... Energy. ACTION: Notice of Open Meeting. SUMMARY: This notice announces an open meeting of the Hydrogen... Avenue, Washington, DC 20585. SUPPLEMENTARY INFORMATION: Purpose of the Committee: The Hydrogen and Fuel...

A Green Process for High-Concentration Ethylene and Hydrogen Production from Methane in a Plasma-Followed-by-Catalyst Reactor

International Nuclear Information System (INIS)

Wang Kangjun; Li Xiaosong; Zhu Aimin

2011-01-01

A green process for the oxygen-free conversion of methane to high-concentration ethylene and hydrogen in a plasma-followed-by-catalyst (PFC) reactor is presented. Without any catalysts and with pure methane used as the feed gas, a stable kilohertz spark discharge leads to an acetylene yield of 64.1%, ethylene yield of 2.5% and hydrogen yield of 59.0% with 80.0% of methane conversion at a methane flow rate of 50 cm 3 /min and a specific input energy of 38.4 kJ/L. In the effluent gas from a stable kilohertz spark discharge reactor, the concentrations of acetylene, ethylene and hydrogen were 18.1%, 0.7% and 66.9%, respectively. When catalysts Pd-Ag/SiO 2 were employed in the second stage with discharge conditions same as in the case of plasma alone, the PFC reactor provides an ethylene yield of 52.1% and hydrogen yield of 43.4%. The concentrations of ethylene and hydrogen in the effluent gas from the PFC reactor were found to be as high as 17.1% and 62.6%, respectively. Moreover, no acetylene was detected in the effluent gas. This means that a high concentration of ethylene and oxygen-free hydrogen can be co-produced directly from methane in the PFC reactor.

Hydrogen and fuel cells emerging technologies and applications

CERN Document Server

Sorensen (Sorensen), Bent

2011-01-01

A hydrogen economy, in which this one gas provides the source of all energy needs, is often touted as the long-term solution to the environmental and security problems associated with fossil fuels. However, before hydrogen can be used as fuel on a global scale we must establish cost effective means of producing, storing, and distributing the gas, develop cost efficient technologies for converting hydrogen to electricity (e.g. fuel cells), and creating the infrastructure to support all this. Sorensen is the only text available that provides up to date coverage of all these issues at a level

H/CNG pathway to hydrogen

International Nuclear Information System (INIS)

Bugyra, W.J.; Martin, D.R.

2004-01-01

'Full text:' The addition of hydrogen to natural gas to produce a 'premium' fuel offers an ideal bridge to the hydrogen and fuel cell era. This pathway provides many of the expected benefits of hydrogen and fuel cells, reduces cost and risk, and facilitates the transition to hydrogen incrementally through existing infrastructure, technologies and channels. The H/CNG pathway is evaluated qualitatively and quantitatively in the context of: barriers to introducing hydrogen infrastructure and how they can be addressed; potential benefits (emissions, energy security) and drawbacks (range, technical compatibility) of H/CNG blended fuels; economics; and, comparative analysis to the use of ethanol in gasoline. Leveraging the NGV industry eases the transition to fuel cells by taking advantage of existing infrastructure, technologies, skills, codes and standards, and provides for incremental change that may be more acceptable to consumers, regulators and incumbent technology providers. The greatest benefits can be achieved through a two-track pathway. One would utilize small amounts of hydrogen in existing NGVs and installed power systems - much as ethanol is added to gasoline. The second introduce products designed specifically to operate on higher levels of H/CNG, like buses, in concentrations where the greatest emission benefits can be achieved. (author)

Novel method for concentrating and drying polymeric nanoparticles: hydrogen bonding coacervate precipitation.

Science.gov (United States)

D'Addio, Suzanne M; Kafka, Concepcion; Akbulut, Mustafa; Beattie, Patrick; Saad, Walid; Herrera, Margarita; Kennedy, Michael T; Prud'homme, Robert K

2010-04-05

Nanoparticles have significant potential in therapeutic applications to improve the bioavailability and efficacy of active drug compounds. However, the retention of nanometer sizes during concentrating or drying steps presents a significant problem. We report on a new concentrating and drying process for poly(ethylene glycol) (PEG) stabilized nanoparticles, which relies upon the unique pH sensitive hydrogen bonding interaction between PEG and polyacid species. In the hydrogen bonding coacervate precipitation (HBCP) process, PEG protected nanoparticles rapidly aggregate into an easily filterable precipitate upon the addition various polyacids. When the resulting solid is neutralized, the ionization of the acid groups eliminates the hydrogen bonded structure and the approximately 100 nm particles redisperse back to within 10% of their original size when poly(acrylic acid) and citric acid are used and 45% when poly(aspartic acid) is used. While polyacid concentrations of 1-5 wt % were used to form the precipitates, the incorporation of the acid into the PEG layer is approximately 1:1 (acid residue):(ethylene oxide unit) in the final dried precipitate. The redispersion of dried beta-carotene nanoparticles protected with PEG-b-poly(lactide-co-glycolide) polymers dried by HBCP was compared with the redispersion of particles dried by freeze-drying with sucrose as a cryprotectant, spray freeze-drying, and normal drying. Freeze-drying with 0, 2, and 12 wt % sucrose solutions resulted in size increases of 350%, 50%, and 6%, respectively. Spray freeze-drying resulted in particles with increased sizes of 50%, but no cryoprotectant and only moderate redispersion energy was required. Conventional drying resulted in solids that could not be redispersed back to nanometer size. The new HBCP process offers a promising and efficient way to concentrate or convert nanoparticle dispersions into a stable dry powder form.

Low concentrations of doxycycline attenuates FasL-induced apoptosis in HeLa cells

Directory of Open Access Journals (Sweden)

Jung Mi Yoon

2015-01-01

Full Text Available BACKGROUND: Doxycycline (DC has been shown to possess non-antibiotic properties including Fas/Fas Ligand (FasL-mediated apoptosis against several tumor types in the concentration range of 10-40 μg/mL. However, the effect of DC in apoptotic signaling at much low concentrations was not studied. METHODS: The present study investigated the attenuation effect of low dose of DC on FasL-induced apoptosis in HeLa cell by the methods of MTT assay, fluorescence microscopy, DNA fragmentation, flow cytometry analysis, and western blotting. RESULTS AND CONCLUSION: In the present findings we showed that low concentration of DC (<2.0 μg/mL exhibited protective effects against FasL-induced apoptosis in HeLa cells. FasL treatment to HeLa cells resulted in a concentration-dependent induction of cell death, and treatment with low concentrations of DC (0.1-2 μg/mL significantly (p < 0.001 attenuated the FasL-induced cell death as measured by 3-(4,5-Dimethylthiazol-2-yl-2,5-diphenyltetrazo-lium bromide (MTT assay. Further, the FasL-induced apoptotic features in HeLa cells, such as morphological changes, DNA fragmentation and cell cycle arrest was also inhibited by DC (0.5 μg/mL. Tetracycline and minocycline also showed similar anti-apoptotic effects but were not significant when compared to DC, tested at same concentrations. Further, DC (0.01-16 μg/mL did not influence the hydrogen peroxide- or cisplatin-induced intrinsic apoptotic pathway in HeLa cells. Protein analysis using Western blotting confirmed that FasL-induced cleavage/activation of cas-pase-8 and caspase-3, were inhibited by DC treatment at low concentration (0.5 μg/mL. Considering the overall data, we report for the first time that DC exhibited anti-apoptotic effects at low concentrations in HeLa cells by inhibition of caspase activation via FasL-induced extrinsic pathway.

Detonation cell size measurements and predictions in hydrogen-air-steam mixtures at elevated temperatures

International Nuclear Information System (INIS)

Ciccarelli, G.; Ginsberg, T.; Boccio, J.; Economos, C.

1994-01-01

The present research reports on the effect of initial mixture temperature on the experimentally measured detonation cell size for hydrogen-air-steam mixtures. Experimental and theoretical research related to combustion phenomena in hydrogen-air-steam mixtures has been ongoing for many years. However, detonation cell size data currently exists or hydrogen-air-steam mixtures up to a temperature of only 400K. Sever accident scenarios have been identified for light water reactors (LWRs) where hydrogen-air mixture temperatures in excess of 400K could be generated within containment. The experiments in this report focus on extending the cell size data base for initial mixture temperatures in excess of 400K. The experiments were carried out in a 10-cm inner-diameter, 6.1-m long heated detonation tube with a maximum operating temperature of 700K and spatial temperature uniformity of ±14K. Detonation cell size measurements provide clear evidence that the effect of hydrogen-air initial gas mixture temperature, in the range 300K--650K, is to decrease cell size and, hence, to increase the sensitivity of the mixture to undergo detonations. The effect of steam content, at any given temperature, is to increase the cell size and, thereby, to decrease the sensitivity of stoichiometric hydrogen-air mixtures. The hydrogen-air detonability limits for the 10-cm inside-diameter test vessel, based upon the onset of single-head spin, decreased from 15 percent by hydrogen at 300K down to about 9 percent hydrogen at 650K. The one-dimensional ZND model does a very good job at predicting the overall trends in the cell size data over the range of hydrogen-air-steam mixture compositions and temperature studied in the experiments

Practical-scale tests of cryogenic molecular sieve for separating low-concentration hydrogen isotopes from helium

International Nuclear Information System (INIS)

Willms, R.S.; Taylor, D.J.; Enoeda, Mikio; Okuno, Kenji

1994-01-01

Earlier bench-scale work at the Tritium Systems Test Assembly (TSTA) at Los Alamos National Laboratory examined a number of adsorbents for their suitability for separating low-concentration hydrogen (no tritium) from helium. One of the effective adsorbents was Linde 5A molecular sieve. Recently, experiments including tritium were conducted using practical-scale adsorbers. These tests used existing cryogenic molecular sieve beds (CMSB's) which each contain about 1.6 kg of Linde 5A molecular sieve. They are part of the TSTA integrated tritium processing system. Gas was fed to each CMSB at about 13 SLPM with a nominal composition of 99% He, 0.98% H 2 and 0.02% HT. In all cases, for an extended period of time, the beds allowed no detectable (via Raman spectroscopy) hydrogen isotopes to escape in the bed effluent. Thereafter, the hydrogen isotopes appeared in the bed exit with a relatively sharp breakthrough curve. This work concludes that cryogenic molecular sieve adsorption is an practical and effective means of separating low-concentration hydrogen isotopes from a helium carrier

77 FR 18243 - Hydrogen and Fuel Cell Technical Advisory Committee (HTAC); Notice of Open Meeting

Science.gov (United States)

2012-03-27

... DEPARTMENT OF ENERGY Hydrogen and Fuel Cell Technical Advisory Committee (HTAC); Notice of Open... open meeting. SUMMARY: This notice announces a meeting of the Hydrogen and Fuel Cell Technical Advisory... Committee: The Hydrogen and Fuel Cell Technical Advisory Committee (HTAC) was established under Section 807...

Integrated hydrogen production process from cellulose by combining dark fermentation, microbial fuel cells, and a microbial electrolysis cell

KAUST Repository

Wang, Aijie; Sun, Dan; Cao, Guangli; Wang, Haoyu; Ren, Nanqi; Wu, Wei-Min; Logan, Bruce E.

2011-01-01

Hydrogen gas production from cellulose was investigated using an integrated hydrogen production process consisting of a dark fermentation reactor and microbial fuel cells (MFCs) as power sources for a microbial electrolysis cell (MEC). Two MFCs

Light induced electrical and macroscopic changes in hydrogenated polymorphous silicon solar cells

Directory of Open Access Journals (Sweden)

Roca i Cabarrocas P.

2012-07-01

Full Text Available We report on light-induced electrical and macroscopic changes in hydrogenated polymorphous silicon (pm-Si:H PIN solar cells. To explain the particular light-soaking behavior of such cells – namely an increase of the open circuit voltage (Voc and a rapid drop of the short circuit current density (Jsc – we correlate these effects to changes in hydrogen incorporation and structural properties in the layers of the cells. Numerous techniques such as current-voltage characteristics, infrared spectroscopy, hydrogen exodiffusion, Raman spectroscopy, atomic force microscopy, scanning electron microscopy and spectroscopic ellipsometry are used to study the light-induced changes from microscopic to macroscopic scales (up to tens of microns. Such comprehensive use of complementary techniques lead us to suggest that light-soaking produces the diffusion of molecular hydrogen, hydrogen accumulation at p-layer/substrate interface and localized delamination of the interface. Based on these results we propose that light-induced degradation of PIN solar cells has to be addressed from not only as a material issue, but also a device point of view. In particular we bring experimental evidence that localized delamination at the interface between the p-layer and SnO2 substrate by light-induced hydrogen motion causes the rapid drop of Jsc.

Laboratory and modeling studies in search of the critical hydrogen concentration

International Nuclear Information System (INIS)

Bartels, David; Wu, Weiqiang; Kanjana, Kotchaphan; Sims, Howard; Henshaw, Jim

2012-09-01

The great success of hydrogen water chemistry (HWC) for primary coolant in nuclear power plants is due to the prevention of net radiolysis and to maintenance of the corrosion potential below -230 mV (SHE) where the rate of stress corrosion cracking is minimized. The critical hydrogen concentration or CHC has been defined as that concentration of excess H 2 in primary coolant water, which prevents net water radiolysis via the chain reaction OH + H 2 ↔H 2 O + H (1, -1) H + H 2 O 2 → H 2 O + OH (2) The principle oxidizing free radical (OH) is thus converted into a reducing radical (H), oxidation products are reduced back to water, and the net result is no chemical change. A set of benchmark experiments at the U2 reactor in Chalk River have been reported in an extensive AECL report, which indicate that the CHC in this reactor is ca. 25 micro-molar. Using the review of yields and reaction rates set forth in another recent AECL report, the Chalk River experiments have been modelled in work at NNL, Harwell. The model was not able to successfully reproduce the experimental CHC, or the steady-state H 2 concentrations (SSH2) in the absence of excess hydrogen. A sensitivity analysis of the entire model was carried out. Essentially three important variables have been found to dominate the result. Reaction rate (1) is overwhelmingly important in determining how much H 2 is needed to accomplish the chain back-reaction. Almost with equal importance, the back reaction (-1) needs to be considered at 300 deg. C, but there is some uncertainty of its magnitude. Finally, the relative yields of radicals and molecular products (i.e. H 2 , H 2 O 2 ) in particular H 2 :OH from the radiolysis are critical. Laboratory studies of hydrogenated water radiation chemistry have been carried out with a van de Graaff electron accelerator at Notre Dame Radiation Laboratory. Modelling of the hydrogen produced as a function of the hydrogen input, suggests that the reaction rate (-1) is ca. two

Solar cell concentrating system

International Nuclear Information System (INIS)

Garg, H.P.; Sharma, V.K.; Agarwal, R.K.

1986-11-01

This study reviews fabrication techniques and testing facilities for different solar cells under concentration which have been developed and tested. It is also aimed to examine solar energy concentrators which are prospective candidates for photovoltaic concentrator systems. This may provide an impetus to the scientists working in the area of solar cell technology

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)

Porous silicon-based direct hydrogen sulphide fuel cells.

Science.gov (United States)

Dzhafarov, T D; Yuksel, S Aydin

2011-10-01

In this paper, the use of Au/porous silicon/Silicon Schottky type structure, as a direct hydrogen sulphide fuel cell is demonstrated. The porous silicon filled with hydrochlorid acid was developed as a proton conduction membrane. The Au/Porous Silicon/Silicon cells were fabricated by first creating the porous silicon layer in single-crystalline Si using the anodic etching under illumination and then deposition Au catalyst layer onto the porous silicon. Using 80 mM H2S solution as fuel the open circuit voltage of 0.4 V was obtained and maximum power density of 30 W/m2 at room temperature was achieved. These results demonstrate that the Au/Porous Silicon/Silicon direct hydrogen sulphide fuel cell which uses H2S:dH2O solution as fuel and operates at room temperature can be considered as the most promising type of low cost fuel cell for small power-supply units.

U.S. Clean Energy Hydrogen and Fuel Cell Technologies: A Competitiveness Analysis

Energy Technology Data Exchange (ETDEWEB)

Fullenkamp, Patrick [Westside Industrial Retention & Expansion Network, Cleveland, OH (United States); Holody, Diane [Westside Industrial Retention & Expansion Network, Cleveland, OH (United States); James, Brian [Strategic Analysis, Inc., Arlington, VA (United States); Houchins, Cassidy [Strategic Analysis, Inc., Arlington, VA (United States); Wheeler, Douglas [DJW Technology, Dublin, OH (United States); Hart, David [E4tech, London (United Kingdom); Lehner, Franz [E4tech, London (United Kingdom)

2017-10-10

The objectives of this project are a 1) Global Competitiveness Analysis of hydrogen and fuel cell systems and components manufactured including 700 bar compressed hydrogen storage system in the U.S., Europe, Asia, and other key areas to be identified to determine the global cost leaders, the best current manufacturing processes, the key factors determining competitiveness, and the potential means of cost reductions; and an 2) Analysis to assess the status of global hydrogen and fuel cell markets. The analysis of units, megawatts by country and by application will focus on polymer electrolyte membrane (PEM) fuel cell systems (automotive and stationary).

The performance of a grid-tied microgrid with hydrogen storage and a hydrogen fuel cell stack

International Nuclear Information System (INIS)

Zhang, Linfeng; Xiang, Jing

2014-01-01

Highlights: • Two microgrids with different structure are simulated. • Their performance are comprehensively evaluated and compared. • The one with DES and a FC stack has high environmental and quality indexes. - Abstract: In a heat-power system, the use of distributed energy generation and storage not only improves system’s efficiency and reliability but also reduce the emission. This paper is focused on the comprehensive performance evaluation of a grid-tied microgrid, which consists of a PV system, a hydrogen fuel cell stack, a PEM electrolyzer, and a hydrogen tank. Electricity and heat are generated in this system, to meet the local electric and heat demands. The surplus electricity can be stored as hydrogen, which is supplied to the fuel cell stack to generate heat and power as needed. The performance of the microgrid is comprehensively evaluated and is compared with another microgrid without a fuel cell stack. As a result, the emission and the service quality in the first system are higher than those in the second one. But they both have the same overall performance

[Life cycle assessment of the infrastructure for hydrogen sources of fuel cell vehicles].

Science.gov (United States)

Feng, Wen; Wang, Shujuan; Ni, Weidou; Chen, Changhe

2003-05-01

In order to promote the application of life cycle assessment and provide references for China to make the project of infrastructure for hydrogen sources of fuel cell vehicles in the near future, 10 feasible plans of infrastructure for hydrogen sources of fuel cell vehicles were designed according to the current technologies of producing, storing and transporting hydrogen. Then life cycle assessment was used as a tool to evaluate the environmental performances of the 10 plans. The standard indexes of classified environmental impacts of every plan were gotten and sensitivity analysis for several parameters were carried out. The results showed that the best plan was that hydrogen will be produced by natural gas steam reforming in central factory, then transported to refuelling stations through pipelines, and filled to fuel cell vehicles using hydrogen gas at last.

Hydrogen passivation of silicon sheet solar cells

International Nuclear Information System (INIS)

Tsuo, Y.S.; Milstein, J.B.

1984-01-01

Significant improvements in the efficiencies of dendritic web and edge-supported-pulling silicon sheet solar cells have been obtained after hydrogen ion beam passivation for a period of ten minutes or less. We have studied the effects of the hydrogen ion beam treatment with respect to silicon material damage, silicon sputter rate, introduction of impurities, and changes in reflectance. The silicon sputter rate for constant ion beam flux of 0.60 +- 0.05 mA/cm 2 exhibits a maximum at approximately 1400-eV ion beam energy

Hydrogen Peroxide Toxicity Induces Ras Signaling in Human Neuroblastoma SH-SY5Y Cultured Cells

Directory of Open Access Journals (Sweden)

Jirapa Chetsawang

2010-01-01

Full Text Available It has been reported that overproduction of reactive oxygen species occurs after brain injury and mediates neuronal cells degeneration. In the present study, we examined the role of Ras signaling on hydrogen peroxide-induced neuronal cells degeneration in dopaminergic neuroblastoma SH-SY5Y cells. Hydrogen peroxide significantly reduced cell viability in SH-SY5Y cultured cells. An inhibitor of the enzyme that catalyzes the farnesylation of Ras proteins, FTI-277, and a competitive inhibitor of GTP-binding proteins, GDP-beta-S significantly decreased hydrogen peroxide-induced reduction in cell viability in SH-SY5Y cultured cells. The results of this study might indicate that a Ras-dependent signaling pathway plays a role in hydrogen peroxide-induced toxicity in neuronal cells.

Hydrogen and fuel cells in the United States Congress

International Nuclear Information System (INIS)

Yacobucci, B.D.

2003-01-01

Over the past few years, the United States Congress has shown increasing interest in the development of hydrogen fuel and fuel cells for transportation, stationary, and mobile applications The high efficiency of fuel cell systems could address some of the concern over increasing dependence on imported petroleum. Further, lower emissions could help promote air quality goals However, many questions remain, including the affordability, safety, overall fuel-cycle efficiency and emissions. These questions, especially those related to cost, have led Members of Congress to enact legislation to speed the development and commercialization of the technologies. This paper discusses congressional action on hydrogen and fuel cells. It provides an overview of the U.S. Congress, and outlines the role of the appropriations process. It then provides a history of federal hydrogen fuel research and development (R and D), both in terms of legislative and executive initiatives, and it describes pending legislation current as of this writing, including bills on energy policy, transportation policy, tax policy, and appropriations. Finally, the paper presents some of the issues that the pending legislation may raise for industry. (author)

Test and Approval Center for Fuel Cell and Hydrogen Technologies: Phase I. Initiation

DEFF Research Database (Denmark)

already spent on these technologies also lead to commercial success. The project ‘Test and Approval Center for Fuel Cell and Hydrogen Technologies: Phase I. Initiation’ was aiming at starting with the Establishment of such a center. The following report documents the achievements within the project...... of the fluctuating wind energy. As the fuel cell and hydrogen technologies come closer to commercialization, development of testing methodology, qualified testing and demonstration become increasingly important. Danish industrial players have expressed a strong need for support in the process to push fuel cell...... and hydrogen technologies from the research and development stage into the commercial domain. A Center to support industry with test, development, analysis, approval, certification, consultation, and training in the areas of fuel cell and hydrogen technologies was needed. Denmark has demonstrated leading...

Core-shell rhodium sulfide catalyst for hydrogen evolution reaction / hydrogen oxidation reaction in hydrogen-bromine reversible fuel cell

Science.gov (United States)

Li, Yuanchao; Nguyen, Trung Van

2018-04-01

Synthesis and characterization of high electrochemical active surface area (ECSA) core-shell RhxSy catalysts for hydrogen evolution oxidation (HER)/hydrogen oxidation reaction (HOR) in H2-Br2 fuel cell are discussed. Catalysts with RhxSy as shell and different percentages (5%, 10%, and 20%) of platinum on carbon as core materials are synthesized. Cyclic voltammetry is used to evaluate the Pt-equivalent mass specific ECSA and durability of these catalysts. Transmission electron microscopy (TEM), X-ray Photoelectron spectroscopy (XPS) and Energy-dispersive X-ray spectroscopy (EDX) techniques are utilized to characterize the bulk and surface compositions and to confirm the core-shell structure of the catalysts, respectively. Cycling test and polarization curve measurements in the H2-Br2 fuel cell are used to assess the catalyst stability and performance in a fuel cell. The results show that the catalysts with core-shell structure have higher mass specific ECSA (50 m2 gm-Rh-1) compared to a commercial catalyst (RhxSy/C catalyst from BASF, 6.9 m2 gm-Rh-1). It also shows better HOR/HER performance in the fuel cell. Compared to the platinum catalyst, the core-shell catalysts show more stable performance in the fuel cell cycling test.

Hydrogen peroxide production is affected by oxygen levels in mammalian cell culture.

Science.gov (United States)

Maddalena, Lucas A; Selim, Shehab M; Fonseca, Joao; Messner, Holt; McGowan, Shannon; Stuart, Jeffrey A

2017-11-04

Although oxygen levels in the extracellular space of most mammalian tissues are just a few percent, under standard cell culture conditions they are not regulated and are often substantially higher. Some cellular sources of reactive oxygen species, like NADPH oxidase 4, are sensitive to oxygen levels in the range between 'normal' physiological (typically 1-5%) and standard cell culture (up to 18%). Hydrogen peroxide in particular participates in signal transduction pathways via protein redox modifications, so the potential increase in its production under standard cell culture conditions is important to understand. We measured the rates of cellular hydrogen peroxide production in some common cell lines, including C2C12, PC-3, HeLa, SH-SY5Y, MCF-7, and mouse embryonic fibroblasts (MEFs) maintained at 18% or 5% oxygen. In all instances the rate of hydrogen peroxide production by these cells was significantly greater at 18% oxygen than at 5%. The increase in hydrogen peroxide production at higher oxygen levels was either abolished or substantially reduced by treatment with GKT 137831, a selective inhibitor of NADPH oxidase subunits 1 and 4. These data indicate that oxygen levels experienced by cells in culture influence hydrogen peroxide production via NADPH oxidase 1/4, highlighting the importance of regulating oxygen levels in culture near physiological values. However, we measured pericellular oxygen levels adjacent to cell monolayers under a variety of conditions and with different cell lines and found that, particularly when growing at 5% incubator oxygen levels, pericellular oxygen was often lower and variable. Together, these observations indicate the importance, and difficulty, of regulating oxygen levels experienced by cells in culture. Copyright © 2017 Elsevier Inc. All rights reserved.

Amperometric cell for subcutaneous detection of hydrogen sulfide in anesthetized experimental animals

International Nuclear Information System (INIS)

Nagy, L; Nagy, G; Filotás, D; Boros, M; Pozsgai, G; Pintér, E

2014-01-01

Hydrogen sulfide (H 2 S) is a toxic gas. It has been recognized that H 2 S evolving in biochemical reactions in living organisms has an important role in different physiologic processes. Nowadays, H 2 S is known as an endogenous messenger molecule. Natural sulfurous spring water has been proved beneficial in the therapy of diseases of the skin and other organs (Boros et al 2013). In vivo real-time detection of local H 2 S concentration is an important but challenging task. We developed a two-electrode amperometric cell for selective subcutaneous detection of H 2 S in anesthetized mice. The cell is a small size implantable gas sensor containing a platinum disc anode and a silver cathode. The selectivity is provided by a membrane permeable only by gases. There is a buffered reversible electrochemical mediator solution in an oxidized form inside the cell. As gaseous H 2 S penetrates into the cell the mediator is reduced, and +0.4 V versus the reference is employed on the platinum working electrode. The reduced mediator is oxidized on the anode surface. The current provides an analytical signal representing the concentration of H 2 S. Appropriate shape, size and membrane material were selected, and optimal working parameters—such as mediator concentration, pH and cell voltage—were determined in vitro. The lower limit of detection in the stirred sample solution at pH = 5.5 was as small as 9.4  ×  10 −7  M and a dynamic concentration range of 0–6  ×  10 –4  M could be achieved. The detecting surfaces of the cell were covered with freshly dissected mouse skin to test dermal H 2 S permeability. In other experiments, the cell was implanted subcutaneously in an anesthetized mouse and the animal was submerged in a buffer solution containing different concentrations of H 2 S so that the skin surface over the sensor was covered by the solution. Measurements of subcutaneous H 2 S concentration were taken. The experiments clearly proved that H 2 S

Inhalation of water electrolysis-derived hydrogen ameliorates cerebral ischemia-reperfusion injury in rats - A possible new hydrogen resource for clinical use.

Science.gov (United States)

Cui, Jin; Chen, Xiao; Zhai, Xiao; Shi, Dongchen; Zhang, Rongjia; Zhi, Xin; Li, Xiaoqun; Gu, Zhengrong; Cao, Liehu; Weng, Weizong; Zhang, Jun; Wang, Liping; Sun, Xuejun; Ji, Fang; Hou, Jiong; Su, Jiacan

2016-10-29

Hydrogen is a kind of noble gas with the character to selectively neutralize reactive oxygen species. Former researches proved that low-concentration of hydrogen can be used to ameliorating cerebral ischemia/reperfusion injury. Hydrogen electrolyzed from water has a hydrogen concentration of 66.7%, which is much higher than that used in previous studies. And water electrolysis is a potential new hydrogen resource for regular clinical use. This study was designed and carried out for the determination of safety and neuroprotective effects of water electrolysis-derived hydrogen. Sprague-Dawley rats were used as experimental animals, and middle cerebral artery occlusion was used to make cerebral ischemia/reperfusion model. Pathologically, tissues from rats in hydrogen inhalation group showed no significant difference compared with the control group in HE staining pictures. The blood biochemical findings matched the HE staining result. TTC, Nissl, and TUNEL staining showed the significant improvement of infarction volume, neuron morphology, and neuron apoptosis in rat with hydrogen treatment. Biochemically, hydrogen inhalation decreased brain caspase-3, 3-nitrotyrosine and 8-hydroxy-2-deoxyguanosine-positive cells and inflammation factors concentration. Water electrolysis-derived hydrogen inhalation had neuroprotective effects on cerebral ischemia/reperfusion injury in rats with the effect of suppressing oxidative stress and inflammation, and it is a possible new hydrogen resource to electrolyze water at the bedside clinically. Copyright © 2016. Published by Elsevier Ltd.

Hydrogen energy

International Nuclear Information System (INIS)

2005-03-01

This book consists of seven chapters, which deals with hydrogen energy with discover and using of hydrogen, Korean plan for hydrogen economy and background, manufacturing technique on hydrogen like classification and hydrogen manufacture by water splitting, hydrogen storage technique with need and method, hydrogen using technique like fuel cell, hydrogen engine, international trend on involving hydrogen economy, technical current for infrastructure such as hydrogen station and price, regulation, standard, prospect and education for hydrogen safety and system. It has an appendix on related organization with hydrogen and fuel cell.

Selective production of hydrogen peroxide and oxidation of hydrogen sulfide in an unbiased solar photoelectrochemical cell

DEFF Research Database (Denmark)

Zong, Xu; Chen, Hongjun; Seger, Brian

2014-01-01

A solar-to-chemical conversion process is demonstrated using a photoelectrochemical cell without external bias for selective oxidation of hydrogen sulfide (H2S) to produce hydrogen peroxide (H2O2) and sulfur (S). The process integrates two redox couples anthraquinone/anthrahydroquinone and I−/I3......−, and conceptually illustrates the remediation of a waste product for producing valuable chemicals....

Air-cooled, hydrogen-air fuel cell

Science.gov (United States)

Shelekhin, Alexander B. (Inventor); Bushnell, Calvin L. (Inventor); Pien, Michael S. (Inventor)

1999-01-01

An air-cooled, hydrogen-air solid polymer electrolyte (SPE) fuel cell with a membrane electrode assembly operatively associated with a fluid flow plate having at least one plate cooling channel extending through the plate and at least one air distribution hole extending from a surface of the cathode flow field into the plate cooling channel.

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.

A dynamic simulation tool for the battery-hybrid hydrogen fuel cell vehicle

Energy Technology Data Exchange (ETDEWEB)

Moore, R.M. [Hawaii Natural Energy Institute, University of Hawaii, Manoa (United States); Ramaswamy, S.; Cunningham, J.M. [California Univ., Berkeley, CA (United States); Hauer, K.H. [xcellvision, Major-Hirst-Strasse 11, 38422 Wolfsburg (Germany)

2006-10-15

This paper describes a dynamic fuel cell vehicle simulation tool for the battery-hybrid direct-hydrogen fuel cell vehicle. The emphasis is on simulation of the hybridized hydrogen fuel cell system within an existing fuel cell vehicle simulation tool. The discussion is focused on the simulation of the sub-systems that are unique to the hybridized direct-hydrogen vehicle, and builds on a previous paper that described a simulation tool for the load-following direct-hydrogen vehicle. The configuration of the general fuel cell vehicle simulation tool has been previously presented in detail, and is only briefly reviewed in the introduction to this paper. Strictly speaking, the results provided in this paper only serve as an example that is valid for the specific fuel cell vehicle design configuration analyzed. Different design choices may lead to different results, depending strongly on the parameters used and choices taken during the detailed design process required for this highly non-linear and n-dimensional system. The primary purpose of this paper is not to provide a dynamic simulation tool that is the ''final word'' for the ''optimal'' hybrid fuel cell vehicle design. The primary purpose is to provide an explanation of a simulation method for analyzing the energetic aspects of a hybrid fuel cell vehicle. (Abstract Copyright [2006], Wiley Periodicals, Inc.)

Detection of hydrogen buildup in initially pure nonhydrogenous liquids

International Nuclear Information System (INIS)

McNeany, S.R.; Jenkins, J.D.

1978-12-01

A technique for monitoring hydrogen buildup in initially pure nonhydrogenous liquids is described in this report. The detection method is based upon the neutron-moderating properties of hydrogen. The analysis leading to the selection and design of a hydrogen-monitoring device is described. An experimental mockup of the device was then constructed and tested for hydrogen sensitivity. A hot cell was used for these tests. A device proved capable of measuring hydrogen concentrations in the range of 0 to 13.0 x 10 27 atoms/m 3 , with an accuracy of about 1.0 x 10 27 atoms/m 3 . A typical measurement can be made in 3 to 5 min. The experimental results confirmed the sensitivities predicted by the analysis and demonstrated that such a device would be practical for hydrogen concentration measurements for criticality control in an HTGR fuel refabrication plant

High hole mobility p-type GaN with low residual hydrogen concentration prepared by pulsed sputtering

Science.gov (United States)

Arakawa, Yasuaki; Ueno, Kohei; Kobayashi, Atsushi; Ohta, Jitsuo; Fujioka, Hiroshi

2016-08-01

We have grown Mg-doped GaN films with low residual hydrogen concentration using a low-temperature pulsed sputtering deposition (PSD) process. The growth system is inherently hydrogen-free, allowing us to obtain high-purity Mg-doped GaN films with residual hydrogen concentrations below 5 × 1016 cm-3, which is the detection limit of secondary ion mass spectroscopy. In the Mg profile, no memory effect or serious dopant diffusion was detected. The as-deposited Mg-doped GaN films showed clear p-type conductivity at room temperature (RT) without thermal activation. The GaN film doped with a low concentration of Mg (7.9 × 1017 cm-3) deposited by PSD showed hole mobilities of 34 and 62 cm2 V-1 s-1 at RT and 175 K, respectively, which are as high as those of films grown by a state-of-the-art metal-organic chemical vapor deposition apparatus. These results indicate that PSD is a powerful tool for the fabrication of GaN-based vertical power devices.

Interpretation of acoustic parameters obtained by EMAR measurement for non-destructive hydrogen concentration measurement in Zr alloy

International Nuclear Information System (INIS)

Nakatsuka, Masafumi; Uchida, Katsuya; Miyazaki, Akihiro; Ishii, Yoshiaki

2007-01-01

An obvious quantitative relation between hydrogen concentrations in zirconium alloy and acoustic anisotropy parameters obtained by the electromagnetic acoustic resonance (EMAR) method was reported. To elucidate the mechanism, the acoustic parameters were calculated based on the elastic theory and the equation of motion. The acoustic parameters of obtained by the EMAR method were interpreted quantitatively using the anisotropic elastic constants of the specimen, and value calculated from texture data for non-hydrogen charged specimens showed good agreement with those obtained by the EMAR method. Calculated temperature dependence of the acoustic anisotropy for the non-hydrogen charged specimen also agreed well with that by the EMAR method. The consistencies demonstrated that the absolute values of the acoustic parameters for non-hydrogen charged specimen can be calculated from both the texture data of (0002) pole figure and the elastic constants of the specimen. Hydrogen addition up to approximately 650ppm was found not to change the original (0002) pole figure and, correspondingly, no hydrogen concentration dependence of the acoustic parameters was obtained from the calculation. These results implied that the zirconium hydride itself played an important role for the change in the acoustic parameters of the hydrogen charged specimens, and the importance of obtaining the information on the elastic constants of the zirconium hydride was pointed out. (author)

Direct-hydrogen-fueled proton-exchange-membrane fuel cell system for transportation applications. Hydrogen vehicle safety report

Energy Technology Data Exchange (ETDEWEB)

Thomas, C.E. [Directed Technologies, Inc., Arlington, VA (United States)

1997-05-01

This report reviews the safety characteristics of hydrogen as an energy carrier for a fuel cell vehicle (FCV), with emphasis on high pressure gaseous hydrogen onboard storage. The authors consider normal operation of the vehicle in addition to refueling, collisions, operation in tunnels, and storage in garages. They identify the most likely risks and failure modes leading to hazardous conditions, and provide potential countermeasures in the vehicle design to prevent or substantially reduce the consequences of each plausible failure mode. They then compare the risks of hydrogen with those of more common motor vehicle fuels including gasoline, propane, and natural gas.

Separation of gaseous hydrogen from a water-hydrogen mixture in a fuel cell power system operating in a weightless environment

Science.gov (United States)

Romanowski, William E. (Inventor); Suljak, George T. (Inventor)

1989-01-01

A fuel cell power system for use in a weightless environment, such as in space, includes a device for removing water from a water-hydrogen mixture condensed from the exhaust from the fuel cell power section of the system. Water is removed from the mixture in a centrifugal separator, and is fed into a holding, pressure operated water discharge valve via a Pitot tube. Entrained nondissolved hydrogen is removed from the Pitot tube by a bleed orifice in the Pitot tube before the water reaches the water discharge valve. Water discharged from the valve thus has a substantially reduced hydrogen content.

2015 DOE Hydrogen and Fuel Cells Program Annual Merit Review and Peer Evaluation Report

Energy Technology Data Exchange (ETDEWEB)

none,

2015-10-01

This report summarizes comments from the Peer Review Panel at the 2015 DOE Hydrogen and Fuel Cells Program Annual Merit Review, held on June 8-12, 2015, in Arlington, Virginia. It covers the program areas of hydrogen production and delivery; hydrogen storage; fuel cells; manufacturing R&D; technology validation; safety, codes, and standards; market transformation; and systems analysis.

2011 DOE Hydrogen and Fuel Cells Program Annual Merit Review and Peer Evaluation Report

Energy Technology Data Exchange (ETDEWEB)

none,

2011-09-01

This report summarizes comments from the Peer Review Panel at the 2011 DOE Hydrogen and Fuel Cells Program Annual Merit Review, held on May 9-13, 2011, in Arlington, Virginia. It covers the program areas of hydrogen production and delivery; hydrogen storage; fuel cells; manufacturing R&D; technology validation; safety, codes, and standards; education; market transformation; and systems analysis.

2013 DOE Hydrogen and Fuel Cells Program Annual Merit Review and Peer Evaluation Report

Energy Technology Data Exchange (ETDEWEB)

none,

2013-10-01

This report summarizes comments from the Peer Review Panel at the 2013 DOE Hydrogen and Fuel Cells Program Annual Merit Review, held on May 13-17, 2013, in Arlington, Virginia. It covers the program areas of hydrogen production and delivery; hydrogen storage; fuel cells; manufacturing R&D; technology validation; safety, codes, and standards; market transformation; and systems analysis.

2014 DOE Hydrogen and Fuel Cells Program Annual Merit Review and Peer Evaluation Report

Energy Technology Data Exchange (ETDEWEB)

none,

2014-10-01

This report summarizes comments from the Peer Review Panel at the 2014 DOE Hydrogen and Fuel Cells Program Annual Merit Review, held on June 16-20, 2014, in Washington, DC. It covers the program areas of hydrogen production and delivery; hydrogen storage; fuel cells; manufacturing R&D; technology validation; safety, codes, and standards; market transformation; and systems analysis.

2012 DOE Hydrogen and Fuel Cells Program Annual Merit Review and Peer Evaluation Report

Energy Technology Data Exchange (ETDEWEB)

none,

2012-09-01

This report summarizes comments from the Peer Review Panel at the 2012 DOE Hydrogen and Fuel Cells Program Annual Merit Review, held on May 14-18, 2012, in Arlington, Virginia. It covers the program areas of hydrogen production and delivery; hydrogen storage; fuel cells; manufacturing R&D; technology validation; safety, codes, and standards; education; market transformation; and systems analysis.

Cryogenic adsorption of low-concentration hydrogen on charcoal, 5A molecular sieve, sodalite, ZSM-5 and Wessalith DAY

International Nuclear Information System (INIS)

Willms, R.S.

1993-01-01

The separation of low-concentration hydrogen isotopes from helium is a processing step that is required for ceramic lithium breeding blanket processing. Cryogenic adsorption is one method of effecting this separation. In this study live adsorbents were considered for this purpose: charcoal, 5A molecular sieve, UOP S-115, ZSM-5 and Wessalith DAY. The first two adsorbents exhibit good equilibrium loadings and are shown to be quite effective at adsorbing low-concentration hydrogen isotopes. The latter three adsorbents display considerably lower equilibrium loadings. This study concludes that by using either charcoal or 5A molecular sieve, cryogenic adsorption would be an effective means of separating hydrogen isotopes from helium

Hydrogenated indium oxide window layers for high-efficiency Cu(In,Ga)Se2 solar cells

International Nuclear Information System (INIS)

Jäger, Timo; Romanyuk, Yaroslav E.; Nishiwaki, Shiro; Bissig, Benjamin; Pianezzi, Fabian; Fuchs, Peter; Gretener, Christina; Tiwari, Ayodhya N.; Döbeli, Max

2015-01-01

High mobility hydrogenated indium oxide is investigated as a transparent contact for thin film Cu(In,Ga)Se 2 (CIGS) solar cells. Hydrogen doping of In 2 O 3 thin films is achieved by injection of H 2 O water vapor or H 2 gas during the sputter process. As-deposited amorphous In 2 O 3 :H films exhibit a high electron mobility of ∼50 cm 2 /Vs at room temperature. A bulk hydrogen concentration of ∼4 at. % was measured for both optimized H 2 O and H 2 -processed films, although the H 2 O-derived film exhibits a doping gradient as detected by elastic recoil detection analysis. Amorphous IOH films are implemented as front contacts in CIGS based solar cells, and their performance is compared with the reference ZnO:Al electrodes. The most significant feature of IOH containing devices is an enhanced open circuit voltage (V OC ) of ∼20 mV regardless of the doping approach, whereas the short circuit current and fill factor remain the same for the H 2 O case or slightly decrease for H 2 . The overall power conversion efficiency is improved from 15.7% to 16.2% by substituting ZnO:Al with IOH (H 2 O) as front contacts. Finally, stability tests of non-encapsulated solar cells in dry air at 80 °C and constant illumination for 500 h demonstrate a higher stability for IOH-containing devices

Hydrogen storage by organic chemical hydrides and hydrogen supply to fuel cells with superheated liquid-film-type catalysis

International Nuclear Information System (INIS)

Hodoshima, S.; Shono, A.; Sato, K.; Saito, Y.

2004-01-01

Organic chemical hydrides, consisting of decalin / naphthalene and tetralin / naphthalene pairs, have been proposed as the storage medium of hydrogen for operating fuel cells in mobile and static modes. The target values in the DOE Hydrogen Plan, U.S., on storage ( 6.5 wt%, 62.0 kg-H 2 / m 3 ) are met with decalin ( 7.3 wt%, 64.8 kg-H 2 / m 3 ). In addition, existing gas stations and tank lorries are available for storage and supply of hydrogen by utilizing the decalin / naphthalene pair, suggesting that decalin is suitable for operating fuel-cell vehicles. Tetralin dehydrogenation proceeds quite rapidly, assuring a predominant power density, though its storage densities ( 3.0 wt%, 28.2 kg-H 2 / m 3 ) are relatively low. Efficient hydrogen supply from decalin or tetralin by heating at 210-280 o C was attained only with the carbon-supported nano-size metal catalysts in the 'superheated liquid-film states' under reactive distillation conditions, where coke formation over the catalyst surface was prevented. The catalyst layer superheated in the liquid-film states gave high reaction rates and conversions, minimizing the evaporation loss under boiling conditions and exergy loss in hydrogen energy systems. (author)

Boundary layer theory approach to the concentration layer adjacent to the ceiling wall of a hydrogen leakage: Axisymmetric impinging and far regions

Energy Technology Data Exchange (ETDEWEB)

El-Amin, M.F.; Kanayama, H. [Department of Mechanical Engineering, Faculty of Engineering, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395 (Japan)

2009-02-15

As hydrogen leaks into a partially open space with a ceiling wall, a boundary layer of hydrogen can be constructed under that wall due to the impingement on the wall and the buoyancy force. The resulting boundary layer can be divided into two regions, namely the stagnation-point region and the far region. When the geometry of the source of the hydrogen leak is circular, such as a pinhole or an o-ring, the behavior of leakage flow will be axisymmetric due to the resulting radial jet. In contrast, when the geometry of the source of the hydrogen leak is planar, such as a crack, the behavior of leakage flow will be planar due to the resulting planar jet. Previously, we studied the planar case in the context of both the stagnation-point flow region [El-Amin MF, Kanayama H. Boundary layer theory approach to the concentration layer adjacent to a ceiling wall at impinging region of a hydrogen leakage. Int J Hydrogen Energy 2008; 33(21): 6393-00] and the far region [El-Amin MF, Inoue M, Kanayama H. Boundary layer theory approach to the concentration layer adjacent to a ceiling wall of a hydrogen leakage: far region. Int J Hydrogen Energy 2008; 33(24):7642-7]. This paper is concerned with both the stagnation-point flow region and the far region of the axisymmetric concentration boundary layer adjacent to a ceiling wall. Flow in the stagnation-point region is treated as Hiemenz flow, while it is treated as Blasius flow in the far region. The current results are compared with the planar cases [El-Amin MF, Kanayama H. Boundary layer theory approach to the concentration layer adjacent to a ceiling wall at impinging region of a hydrogen leakage. Int J Hydrogen Energy 2008; 33(21): 6393-00; El-Amin MF, Inoue M, Kanayama H. Boundary layer theory approach to the concentration layer adjacent to a ceiling wall of a hydrogen leakage: far region. Int J Hydrogen Energy 2008; 33(24):7642-7] for both stagnation-point flow and far regions. Both momentum and concentration boundary layer

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

Design of a photovoltaic-hydrogen-fuel cell energy system

Energy Technology Data Exchange (ETDEWEB)

Lehman, P A; Chamberlin, C E [Humboldt State Univ., Arcata, CA (US). Dept. of Environmental Resources Engineering

1991-01-01

The design of a stand-alone renewable energy system using hydrogen (H{sub 2}) as the energy storage medium and a fuel cell as the regeneration technology is reported. The system being installed at the Humboldt State University Telonicher Marine Laboratory consists of a 9.2 kW photovoltaic (PV) array coupled to a high pressure, bipolar alkaline electrolyser. The array powers the Laboratory's air compressor system whenever possible; excess power is shunted to the electrolyser for hydrogen and oxygen (O{sub 2}) production. When the array cannot provide sufficient power, stored hydrogen and oxygen are furnished to a proton exchange membrane fuel cell which, smoothly and without interruption, supplies the load. In reporting the design, details of component selection, sizing, and integration, control system logic and implementation, and safety considerations are discussed. Plans for a monitoring network to chronicle system performance are presented, questions that will be addressed through the monitoring program are included, and the present status of the project is reported. (Author).

Hydrogen peroxide as sustainable fuel: electrocatalysts for production with a solar cell and decomposition with a fuel cell.

Science.gov (United States)

Yamada, Yusuke; Fukunishi, Yurie; Yamazaki, Shin-ichi; Fukuzumi, Shunichi

2010-10-21

Hydrogen peroxide was electrochemically produced by reducing oxygen in an aqueous solution with [Co(TCPP)] as a catalyst and photovoltaic solar cell operating at 0.5 V. Hydrogen peroxide thus produced is utilized as a fuel for a one-compartment fuel cell with Ag-Pb alloy nanoparticles as the cathode.

Investigation of a novel concept for hydrogen production by PEM water electrolysis integrated with multi-junction solar cells

International Nuclear Information System (INIS)

Ferrero, Domenico; Santarelli, Massimo

2017-01-01

Highlights: • A 2D model of a PEM water electrolyzer is developed and validated. • A novel system integrating PEM and multi-junction solar cells is proposed. • The model is applied to the simulation of the novel system. • The integration of PEM and MJ cells enhances the hydrogen production efficiency. - Abstract: A 2D finite element model of a high-pressure PEM water electrolyzer is developed and validated over experimental data obtained from a demonstration prototype. The model includes the electrochemical, fluidic and thermal description of the repeating unit of a PEM electrolyzer stack. The model is applied to the simulation of a novel system composed by a high-temperature, high-pressure PEM electrochemical cell coupled with a photovoltaic multi-junction solar cell installed in a solar concentrator. The thermo-electrochemical characterization of the solar-driven PEM electrolysis system is presented and the advantages of the high-temperature operation and of the direct coupling of electrolyzer and solar cell are assessed. The results show that the integration of the multi-junction cell enhances the performance of the electrolyzer and allows to achieve higher system efficiency compared to separated photovoltaic generation and hydrogen production by electrolysis.

Stability of MOF-5 in a hydrogen gas environment containing fueling station impurities

DEFF Research Database (Denmark)

Ming, Yang; Purewal, Justin; Yang, Jun

2016-01-01

in the hydrogen fuel stream. Hydrogen intended for use in fuel cell vehicles should satisfy purity standards, such as those outlined in SAE J2719. This standard limits the concentration of certain species in the fuel stream based primarily on their deleterious effects on PEM fuel cells. However, the impact...

Measurement of dissolved hydrogen and hydrogen gas transfer in a hydrogen-producing reactor

Energy Technology Data Exchange (ETDEWEB)

Shizas, I.; Bagley, D.M. [Toronto Univ., ON (Canada). Dept. of Civil Engineering

2004-07-01

This paper presents a simple method to measure dissolved hydrogen concentrations in the laboratory using standard equipment and a series of hydrogen gas transfer tests. The method was validated by measuring hydrogen gas transfer parameters for an anaerobic reactor system that was purged with 10 per cent carbon dioxide and 90 per cent nitrogen using a coarse bubble diffuser stone. Liquid samples from the reactor were injected into vials and hydrogen was allowed to partition between the liquid and gaseous phases. The concentration of dissolved hydrogen was determined by comparing the headspace injections onto a gas chromatograph and a standard curve. The detection limit was 1.0 x 10{sup -5} mol/L of dissolved hydrogen. The gas transfer rate for hydrogen in basal medium and anaerobic digester sludge was used to validate the method. Results were compared with gas transfer models. In addition to monitoring dissolved hydrogen in reactor systems, this method can help improve hydrogen production potential. 1 ref., 4 figs.

Ascorbate concentrations in vitro and in vivo, and their role in the radiation response of cells

International Nuclear Information System (INIS)

Stratford, M.R.L.; Hodgkiss, R.J.

1985-01-01

Hydrogen-atom or electron-transfer reactions of ascorbate are often invoked in discussing its potential role in radiobiology and free radical damage by cytotoxins, but detailed information on actual levels in experimental systems is lacking. A range of 0-250 μM ascorbate is present in several commonly used mammalian cell culture media. V79 379A Chinese hamster cells can concentrate ascorbate from medium containing 200 or 500 μM ascorbate but when ascorbate is absent in medium, cells do not appear to contain a significant amount. Tumour concentrations are approximately 1mM, similar to that of glutathione (GSH). There is much current interest in depleting cells of GSH to enhance radiosensitivity, and ascorbate is maintained by a GSH dependent enzyme, glutathione dehydrogenase. Data is presented on the effect of GSH depletion by buthionine sulphoximine on cell and tumour ascorbate levels, and the effect of ascorbate on in vitro radiosensitivity, and misonidazole sensitizing efficiency

Hydrogen-boron complexes in heavily boron-doped silicon treated with high concentration of hydrogen atoms

International Nuclear Information System (INIS)

Fukata, N.; Fukuda, S.; Sato, S.; Ishioka, K.; Kitajima, M.; Hishita, S.; Murakami, K.

2006-01-01

The formation of hydrogen (H)-related complexes was investigated in boron (B)-doped Si treated with high concentration of H. The isotope shifts of H-related Raman peaks by replacement of H to deuterium and 1 B to 11 B clearly showed the formation of the B-H complexes in which H directly bonds to B in Si. The results of the resistivity measurements suggested that the B acceptors are passivated via the formation of the B-H complexes, as well as the well-known passivation center in B-doped Si, namely, H-B passivation center

Compact hydrogen production systems for solid polymer fuel cells

Science.gov (United States)

Ledjeff-Hey, K.; Formanski, V.; Kalk, Th.; Roes, J.

Generally there are several ways to produce hydrogen gas from carbonaceous fuels like natural gas, oil or alcohols. Most of these processes are designed for large-scale industrial production and are not suitable for a compact hydrogen production system (CHYPS) in the power range of 1 kW. In order to supply solid polymer fuel cells (SPFC) with hydrogen, a compact fuel processor is required for mobile applications. The produced hydrogen-rich gas has to have a low level of harmful impurities; in particular the carbon monoxide content has to be lower than 20 ppmv. Integrating the reaction step, the gas purification and the heat supply leads to small-scale hydrogen production systems. The steam reforming of methanol is feasible at copper catalysts in a low temperature range of 200-350°C. The combination of a small-scale methanol reformer and a metal membrane as purification step forms a compact system producing high-purity hydrogen. The generation of a SPFC hydrogen fuel gas can also be performed by thermal or catalytic cracking of liquid hydrocarbons such as propane. At a temperature of 900°C the decomposition of propane into carbon and hydrogen takes place. A fuel processor based on this simple concept produces a gas stream with a hydrogen content of more than 90 vol.% and without CO and CO2.

Artificial photosynthesis for production of hydrogen peroxide and its fuel cells.

Science.gov (United States)

Fukuzumi, Shunichi

2016-05-01

The reducing power released from photosystem I (PSI) via ferredoxin enables the reduction of NADP(+) to NADPH, which is essential in the Calvin-Benson cycle to make sugars in photosynthesis. Alternatively, PSI can reduce O2 to produce hydrogen peroxide as a fuel. This article describes the artificial version of the photocatalytic production of hydrogen peroxide from water and O2 using solar energy. Hydrogen peroxide is used as a fuel in hydrogen peroxide fuel cells to make electricity. The combination of the photocatalytic H2O2 production from water and O2 using solar energy with one-compartment H2O2 fuel cells provides on-site production and usage of H2O2 as a more useful and promising solar fuel than hydrogen. This article is part of a Special Issue entitled Biodesign for Bioenergetics--The design and engineering of electronc transfer cofactors, proteins and protein networks, edited by Ronald L. Koder and J.L. Ross Anderson. Copyright © 2016 Elsevier B.V. All rights reserved.

Elastic recoil detection analysis for the determination of hydrogen concentration profiles in switchable mirrors

International Nuclear Information System (INIS)

Huisman, M.C.; Molen, S.J. van der; Vis, R.D.

1999-01-01

Switchable mirrors [J.N. Huiberts, R. Griessen, J.H. Rector, R.J. Wijngaarden, J.P. Dekker, D.G. de Groot, N.J. Koeman, Nature 380 (1996) 231; J.N Huiberts, J.H. Rector, R.J. Wijngaarden, S. Jetten, D. de Groot, B. Dam, N.J.. Koeman, R. Griessen, B. Hjoervarsson, S Olafsson, Y.S. Cho, J. Alloys and Compounds 239 (1996) 158; F.J.A. den Broeder, S.J. van der Molen, M. Kremers, J. N. Huiberts, D.G. Nagengast, A.T.M. van Gogh, W.H. Huisman, N. J. Koeman, B. Dam, J.H. Rector, S. Plota, M. Haaksma, R.M.N. Hanzen, R.M. Jungblut, P.A. Duine, R. Griessen, Nature 394 (1998) 656] made of thin films of Y, La or rare-earth (RE) metals exhibit spectacular changes in their optical and electrical properties upon hydrogen loading. The study of these materials has indicated that the occurring phenomena are highly sensitive to the actual hydrogen concentration in these materials. In this paper elastic recoil detection analysis (ERDA) is used as a tool to measure hydrogen concentrations on a micrometer scale. The measurements have been performed using a 4 He 2+ ion beam from a 1.7 MV Pelletron accelerator. The ion beam can be focused routinely to a spot size of approximately 10 μm 2 . The experimental set-up enables the simultaneous measurement of Rutherford backscattering spectrometry (RBS) as well as particle induced X-ray emission (PIXE) spectra, which provide complementary information. The results of ERDA measurements on laterally diffused YH x (0< x<3) samples with a qualitatively known hydrogen concentration profile are presented and discussed. The calibration of the microbeam set-up and possible improvement of the measurement technique are described

Elastic recoil detection analysis for the determination of hydrogen concentration profiles in switchable mirrors

Energy Technology Data Exchange (ETDEWEB)

Huisman, M.C. E-mail: huisman@nat.vu.nl; Molen, S.J. van der; Vis, R.D

1999-09-02

Switchable mirrors [J.N. Huiberts, R. Griessen, J.H. Rector, R.J. Wijngaarden, J.P. Dekker, D.G. de Groot, N.J. Koeman, Nature 380 (1996) 231; J.N Huiberts, J.H. Rector, R.J. Wijngaarden, S. Jetten, D. de Groot, B. Dam, N.J.. Koeman, R. Griessen, B. Hjoervarsson, S Olafsson, Y.S. Cho, J. Alloys and Compounds 239 (1996) 158; F.J.A. den Broeder, S.J. van der Molen, M. Kremers, J. N. Huiberts, D.G. Nagengast, A.T.M. van Gogh, W.H. Huisman, N. J. Koeman, B. Dam, J.H. Rector, S. Plota, M. Haaksma, R.M.N. Hanzen, R.M. Jungblut, P.A. Duine, R. Griessen, Nature 394 (1998) 656] made of thin films of Y, La or rare-earth (RE) metals exhibit spectacular changes in their optical and electrical properties upon hydrogen loading. The study of these materials has indicated that the occurring phenomena are highly sensitive to the actual hydrogen concentration in these materials. In this paper elastic recoil detection analysis (ERDA) is used as a tool to measure hydrogen concentrations on a micrometer scale. The measurements have been performed using a {sup 4}He{sup 2+} ion beam from a 1.7 MV Pelletron accelerator. The ion beam can be focused routinely to a spot size of approximately 10 {mu}m{sup 2}. The experimental set-up enables the simultaneous measurement of Rutherford backscattering spectrometry (RBS) as well as particle induced X-ray emission (PIXE) spectra, which provide complementary information. The results of ERDA measurements on laterally diffused YH{sub x} (0hydrogen concentration profile are presented and discussed. The calibration of the microbeam set-up and possible improvement of the measurement technique are described.

Hydrogen storage material, electrochemically active material, electrochemical cell and electronic equipment

NARCIS (Netherlands)

2008-01-01

The invention relates to a hydrogen storage material comprising an alloy of magnesium. The invention further relates to an electrochemically active material and an electrochemical cell provided with at least one electrode comprising such a hydrogen storage material. Also, the invention relates to

A synergetic use of hydrogen and fuel cells in human spaceflight power systems

Science.gov (United States)

Belz, S.

2016-04-01

Hydrogen is very flexible in different fields of application of energy conversion. It can be generated by water electrolysis. Stored in tanks it is available for re-electrification by fuel cells. But it is not only the power system, which benefits from use of hydrogen, but also the life support system, which can contain hydrogen consuming technologies for recycling management (e.g. carbon dioxide removal and waste combustion processes). This paper points out various fields of hydrogen use in a human spaceflight system. Depending on mission scenarios, shadow phases, and the need of energy storage, regenerative fuel cell systems can be more efficient than secondary batteries. Here, different power storage concepts are compared by equivalent system mass calculation, thus including impact in the peripheral structure (volume, thermal management, etc.) on the space system. It is also focused on the technical integration aspect, e.g. which peripheral components have to be adapted when hydrogen is also used for life support technologies and what system mass benefit can be expected. Finally, a recommendation is given for the following development steps for a synergetic use of hydrogen and fuel cells in human spaceflight power systems.

Development of a Micro-Fiber Nickel Electrode for Nickel-Hydrogen Cell

Science.gov (United States)

Britton, Doris L.

1996-01-01

The development of a high specific energy battery is one of the objectives of the lightweight nickel-hydrogen (NiH2) program at the NASA Lewis Research Center. The approach has been to improve the nickel electrode by continuing combined in-house and contract efforts to develop a more efficient and lighter weight electrode for the nickel-hydrogen fuel cell. Small fiber diameter nickel plaques are used as conductive supports for the nickel hydroxide active material. These plaques are commercial products and have an advantage of increased surface area available for the deposition of active materials. Initial tests include activation and capacity measurements at different discharge levels followed by half-cell cycle testing at 80 percent depth-of-discharge in a low Earth orbit regime. The electrodes that pass the initial tests are life cycle tested in a boiler plate nickel-hydrogen cell before flightweight designs are built and tested.

A new principle for low-cost hydrogen sensors for fuel cell technology safety

Energy Technology Data Exchange (ETDEWEB)

Liess, Martin [Rhein Main University of Applied Sciences, Rüsselsheim, Wiesbaden (Germany)

2014-03-24

Hydrogen sensors are of paramount importance for the safety of hydrogen fuel cell technology as result of the high pressure necessary in fuel tanks and its low explosion limit. I present a novel sensor principle based on thermal conduction that is very sensitive to hydrogen, highly specific and can operate on low temperatures. As opposed to other thermal sensors it can be operated with low cost and low power driving electronics. On top of this, as sensor element a modified standard of-the shelf MEMS thermopile IR-sensor can be used. The sensor principle presented is thus suited for the future mass markets of hydrogen fuel cell technology.S.

Design of a microbial fuel cell and its transition to microbial electrolytic cell for hydrogen production by electrohydrogenesis.

Science.gov (United States)

Gupta, Pratima; Parkhey, Piyush; Joshi, Komal; Mahilkar, Anjali

2013-10-01

Anaerobic bacteria were isolated from industrial wastewater and soil samples and tested for exoelectrogenic activity by current production in double chambered microbial fuel cell (MFC), which was further transitioned into a single chambered microbial electrolytic cell to test hydrogen production by electrohydrogenesis. Of all the cultures, the isolate from industrial water sample showed the maximum values for current = 0.161 mA, current density = 108.57 mA/m2 and power density = 48.85 mW/m2 with graphite electrode. Maximum voltage across the cell, however, was reported by the isolate from sewage water sample (506 mv) with copper as electrode. Tap water with KMnO4 was the best cathodic electrolyte as the highest values for all the measured MFC parameters were reported with it. Once the exoelectrogenic activity of the isolates was confirmed by current production, these were tested for hydrogen production in a single chambered microbial electrolytic cell (MEC) modified from the MFC. Hydrogen production was reported positive from co-culture of isolates of both the water samples and co-culture of one soil and one water sample. The maximum rate and yield of hydrogen production was 0.18 m3H2/m3/d and 3.2 mol H2/mol glucose respectively with total hydrogen production of 42.4 mL and energy recovery of 57.4%. Cumulative hydrogen production for a five day cycle of MEC operation was 0.16 m3H2/m3/d.

Near-term markets for PEM fuel cell power modules: industrial vehicles and hydrogen recovery

International Nuclear Information System (INIS)

Chintawar, P.S.; Block, G.

2004-01-01

'Full text:' Nuvera Fuel Cells, Inc. is a global leader in the development and advancement of multifuel processing and fuel cell technology. With offices located in Italy and the USA, Nuvera is committed to advancing the commercialization of hydrogen fuel cell power modules for industrial vehicles and equipment and stationary applications by 2006, natural gas fuel cell power systems for cogeneration applications by 2007, and on-board gasoline fuel processors and fuel cell stacks for automotive applications by 2010. Nuvera Fuel Cells Europe is ISO 9001:2000 certified for 'Research, Development, Design, Production and Servicing of Fuel Cell Stacks and Fuel Cell Systems.' In the chemical industry, one of the largest operating expenses today is the cost of electricity. For example, caustic soda and chlorine are produced today using industrial membrane electrolysis which is an energy intensive process. Production of 1 metric ton of caustic soda consumes 2.5 MWh of energy. However, about 20% of the electricity consumed can be recovered by converting the hydrogen byproduct of the caustic soda production process into electricity via PEM fuel cells. The accessible market is a function of the economic value of the hydrogen whether flared, used as fuel, or as chemical. Responding to this market need, we are currently developing large hydrogen fuel cell power modules 'Forza' that use excess hydrogen to produce electricity, representing a practical economic alternative to reducing the net electricity cost. Due for commercial launch in 2006, Forza is a low-pressure, steady state, base-load power generation solution that will operate at high efficiency and 100% capacity over a 24-hour period. We believe this premise is also true for chemical and electrochemical plants and companies that convert hydrogen to electricity using renewable sources like windmills or hydropower. The second near-term market that Nuvera is developing utilizes a 5.5 kW hydrogen fueled power module 'H 2 e

Hydrogen millennium

International Nuclear Information System (INIS)

Bose, T.K.; Benard, P.

2000-05-01

The 10th Canadian Hydrogen Conference was held at the Hilton Hotel in Quebec City from May 28 to May 31, 2000. The topics discussed included current drivers for the hydrogen economy, the international response to these drivers, new initiatives, sustainable as well as biological and hydrocarbon-derived production of hydrogen, defense applications of fuel cells, hydrogen storage on metal hydrides and carbon nanostructures, stationary power and remote application, micro-fuel cells and portable applications, marketing aspects, fuel cell modeling, materials, safety, fuel cell vehicles and residential applications. (author)

Destructive physical analysis of spaceflight qualified nickel-hydrogen battery cells

Energy Technology Data Exchange (ETDEWEB)

Coates, D.; Francisco, J.; Giertz, K.; Smith, R.; Nowlin, G. [Eagle-Picher Industries, Inc., Joplin, MO (United States). Advanced Systems Operation

1996-11-01

Nickel-hydrogen (NiH{sub 2}) batteries are extensively used in the aerospace industry as the power system of choice in earth-orbital spacecraft. The batteries are typically required to support a 10--15 year geosynchronous-earth-orbit (GEO) mission or thousands of charge/discharge cycles in low-earth-orbit (LEO). Reliability requirements for this application are extensive and include the routine destructive physical analysis (DPA) of sample flight production battery cells. Standard procedures have been developed over the past 15 years for the disassembly, handling and detailed analysis of the cell components. These include mechanical, thermal and impedance analysis, electrolyte concentration and distribution, gas management, corrosion, dye penetrant and radiographic inspection, and several chemical and electrochemical analytical procedures for the battery electrodes and separator materials. Electrolyte management is a critical issue in the electrolyte-starved NiH{sub 2} cell design and procedures have been developed to particularly address this aspect of the DPA analysis. Specific analytical procedures for cell components includes nickel electrode active material and sinter substrate corrosion analysis, scanning electron microscopy (SEM), energy dispersive x-ray analysis (EDX), cobalt ion, potassium-carbonate and anion analysis. Many of these procedures are also applicable to aerospace battery systems in general and to other alkaline rechargeable batteries.

Hydrogen fuel - Universal energy

Science.gov (United States)

Prince, A. G.; Burg, J. A.

The technology for the production, storage, transmission, and consumption of hydrogen as a fuel is surveyed, with the physical and chemical properties of hydrogen examined as they affect its use as a fuel. Sources of hydrogen production are described including synthesis from coal or natural gas, biomass conversion, thermochemical decomposition of water, and electrolysis of water, of these only electrolysis is considered economicially and technologically feasible in the near future. Methods of production of the large quantities of electricity required for the electrolysis of sea water are explored: fossil fuels, hydroelectric plants, nuclear fission, solar energy, wind power, geothermal energy, tidal power, wave motion, electrochemical concentration cells, and finally ocean thermal energy conversion (OTEC). The wind power and OTEC are considered in detail as the most feasible approaches. Techniques for transmission (by railcar or pipeline), storage (as liquid in underwater or underground tanks, as granular metal hydride, or as cryogenic liquid), and consumption (in fuel cells in conventional power plants, for home usage, for industrial furnaces, and for cars and aircraft) are analyzed. The safety problems of hydrogen as a universal fuel are discussed, noting that they are no greater than those for conventional fuels.

Inductively coupled hydrogen plasma processing of AZO thin films for heterojunction solar cell applications

International Nuclear Information System (INIS)

Zhou, H.P.; Xu, S.; Zhao, Z.; Xiang, Y.

2014-01-01

Highlights: • A high-density plasma reactor of inductively coupled plasma source is used in this work. • The conductivity and transmittance can be enhanced simultaneously in the hydrogen process. • The formation of additional donors and passivation due to the hydrogen plasma processing. • The photovoltaic improvement due to the improved AZO layer and hetero-interface quality in the solar cells. - Abstract: Al-doped ZnO (AZO) thin films deposited by means of RF magnetron sputtering were processed in a low frequency inductively coupled plasma of H 2 , aiming at heterojunction (HJ) solar cell applications. A variety of characterization results show that the hydrogen plasma processing exerts a significant influence on the microstructures, electrical and optical properties of the AZO films. The incorporation of hydrogen under the optimum treatment simultaneously promoted the transmittance and conductivity due to the hydrogen associated passivation effect on the native defects and the formation of shallow donors in the films, respectively. A p-type c-Si based HJ solar cell with a front AZO contact was also treated in as-generated non-equilibrium hydrogen plasma and the photovoltaic performance of the solar cell was prominently improved. The underlying mechanism was discussed in terms of the beneficial impacts of high-density hydrogen plasma on the properties of AZO itself and the hetero-interfaces involved in the HJ structure (interface defect and energy band configuration)

Hydrogen-Oxygen PEM Regenerative Fuel Cell at NASA Glenn Research Center

Science.gov (United States)

Bents, David J.

2004-01-01

The NASA Glenn Research Center has constructed a closed-cycle hydrogen-oxygen PEM regenerative fuel cell (RFC) to explore its potential use as an energy storage device for a high altitude solar electric aircraft. Built up over the last 2 years from specialized hardware and off the shelf components the Glenn RFC is a complete "brassboard" energy storage system which includes all the equipment required to (1) absorb electrical power from an outside source and store it as pressurized hydrogen and oxygen and (2) make electrical power from the stored gases, saving the product water for re-use during the next cycle. It consists of a dedicated hydrogen-oxygen fuel cell stack and an electrolyzer stack, the interconnecting plumbing and valves, cooling pumps, water transfer pumps, gas recirculation pumps, phase separators, storage tanks for oxygen (O2) and hydrogen (H2), heat exchangers, isolation valves, pressure regulators, nitrogen purge provisions, instrumentation, and other components. It specific developmental functions include: (1) Test fuel cells and fuel cell components under repeated closed-cycle operation (nothing escapes; everything is used over and over again). (2) Simulate diurnal charge-discharge cycles (3) Observe long-term system performance and identify degradation and loss mechanisms. (4) Develop safe and convenient operation and control strategies leading to the successful development of mission-capable, flight-weight RFC's.

Molecular Dynamics Investigation of the Effects of Concentration on Hydrogen Bonding in Aqueous Solutions of Methanol, Ethylene Glycol and Glycerol

International Nuclear Information System (INIS)

Zhang, Ning; Li, Weizhong; Chen, Cong; Zuo, Jianguo; Weng, Lindong

2013-01-01

Hydrogen bonding interaction between alcohols and water molecules is an important characteristic in the aqueous solutions of alcohols. In this paper, a series of molecular dynamics simulations have been performed to investigate the aqueous solutions of low molecular weight alcohols (methanol, ethylene glycol and glycerol) at the concentrations covering a broad range from 1 to 90 mol %. The work focuses on studying the effect of the alcohols molecules on the hydrogen bonding of water molecules in binary mixtures. By analyzing the hydrogen bonding ability of the hydroxyl (-OH) groups for the three alcohols, it is found that the hydroxyl group of methanol prefers to form more hydrogen bonds than that of ethylene glycol and glycerol due to the intra-and intermolecular effects. It is also shown that concentration has significant effect on the ability of alcohol molecule to hydrogen bond water molecules. Understanding the hydrogen bonding characteristics of the aqueous solutions is helpful to reveal the cryoprotective mechanisms of methanol, ethylene glycol and glycerol in aqueous solutions

Correction factor to determine total hydrogen+deuterium concentration obtained by inert gas fusion-thermal conductivity detection (IGF- TCD) technique

International Nuclear Information System (INIS)

Ramakumar, K.L.; Sesha Sayi, Y.; Shankaran, P.S.; Chhapru, G.C; Yadav, C.S.; Venugopal, V.

2004-01-01

The limitation of commercially available dedicated equipment based on Inert Gas Fusion- Thermal Conductivity Detection (IGF - TCD) for the determination of hydrogen+deuterium is described. For a given molar concentration, deuterium is underestimated vis a vis hydrogen because of lower thermal conductivity and not considering its molecular weight in calculations. An empirical correction factor based on the differences between the thermal conductivities of hydrogen, deuterium and the carrier gas argon, and the mole fraction of deuterium in the sample has been derived to correct the observed hydrogen+deuterium concentration. The corrected results obtained by IGF - TCD technique have been validated by determining hydrogen and deuterium contents in a few samples using an independent method based on hot vacuum extraction-quadrupole mass spectrometry (HVE-QMS). Knowledge of mole fraction of deuterium (XD) is necessary to effect the correction. The correction becomes insignificant at low X D values (XD < 0.2) as the precision in the IGF measurements is comparable with the extent of correction. (author)

Near-surface alloys for hydrogen fuel cell applications

DEFF Research Database (Denmark)

Greeley, Jeffrey Philip; Mavrikakis, Manos

2006-01-01

of CO with relatively facile H-2 activation is nearly ideal for this application. We suggest that. as nanoscale materials synthesis techniques improve, it will become feasible to reproducibly prepare NSAs with highly specified surface structures, resulting in the design and manufacture of a wide variety...... facile H-2 activation. These NSAs could, potentially, facilitate highly selective hydrogenation reactions at low temperatures. In the present work, the suitability of NSAs for use as hydrogen fuel cell anodes has been evaluated: the combination of properties, possessed by selected NSAs, of weak binding...... of such materials for use in fuel cells and in an ever. increasing range of catalytic applications. Furthermore, we introduce a new concept for NSA-defect sites, which could be responsible for the promotional catalytic effects of a second metal added. even in minute quantities, to a host metal catalyst....

Fuel cell cars in a microgrid for synergies between hydrogen and electricity networks

NARCIS (Netherlands)

Alavi, F.; Park Lee, H.; van de Wouw, N.; De Schutter, B.H.K.; Lukszo, Z.

2017-01-01

Fuel cell electric vehicles convert chemical energy of hydrogen into electricity to power their motor. Since cars are used for transport only during a small part of the time, energy stored in the on-board hydrogen tanks of fuel cell vehicles can be used to provide power when cars are parked. In

Fuel cell cars in a microgrid for synergies between hydrogen and electricity networks

NARCIS (Netherlands)

Alavi, F.; Park Lee, E.; van de Wouw, N.; de Schutter, B.; Lukszo, Z.

2017-01-01

Fuel cell electric vehicles convert chemical energy of hydrogen into electricity to power their motor. Since cars are used for transport only during a small part of the time, energy stored in the on-board hydrogen tanks of fuel cell vehicles can be used to provide power when cars are parked. In this

Repression of hydrogen uptake using conjugated oligoelectrolytes in microbial electrolysis cells

KAUST Repository

Hou, Huijie

2014-11-01

Copyright © 2014, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved. DSBN+, a conjugated oligoelectrolyte (COE), was added to microbial electrolysis cells (MECs) to improve hydrogen recovery. The volume of hydrogen gas recovered in a fedbatch cycle of mixed culture MECs increased by 126× compared to controls (no COE addition), mainly by preventing the loss of hydrogen to methane production. Performance in pure culture MECs fed with Geobacter sulfurreducens increased by factors of 10.5 in terms of energy yield, 2.1 in COD removal, and 11.8 in hydrogen yield. Hydrogen gas recycling was reduced, and the volume of hydrogen gas recovered increased by 6.5× compared to controls. Minimal methane production and a lack of hydrogen gas uptake by G. sulfurreducens suggested that the COEs increased hydrogen recoveries by interfering with hydrogen uptake by hydrogenotrophic methanogens but also by exoelectrogenic bacteria. COEs may therefore be useful for inhibiting the activities of certain hydrogenases, although the mechanism of inhibition needs further investigation.

Repression of hydrogen uptake using conjugated oligoelectrolytes in microbial electrolysis cells

KAUST Repository

Hou, Huijie; Chen, Xiaofen; Liu, Jia; Zhu, Xiuping; Bazan, Guillermo C.; Logan, Bruce E.

2014-01-01

Copyright © 2014, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved. DSBN+, a conjugated oligoelectrolyte (COE), was added to microbial electrolysis cells (MECs) to improve hydrogen recovery. The volume of hydrogen gas recovered in a fedbatch cycle of mixed culture MECs increased by 126× compared to controls (no COE addition), mainly by preventing the loss of hydrogen to methane production. Performance in pure culture MECs fed with Geobacter sulfurreducens increased by factors of 10.5 in terms of energy yield, 2.1 in COD removal, and 11.8 in hydrogen yield. Hydrogen gas recycling was reduced, and the volume of hydrogen gas recovered increased by 6.5× compared to controls. Minimal methane production and a lack of hydrogen gas uptake by G. sulfurreducens suggested that the COEs increased hydrogen recoveries by interfering with hydrogen uptake by hydrogenotrophic methanogens but also by exoelectrogenic bacteria. COEs may therefore be useful for inhibiting the activities of certain hydrogenases, although the mechanism of inhibition needs further investigation.

2010 Hydrogen and Fuel Cell Global Commercialization & Development Update

Energy Technology Data Exchange (ETDEWEB)

none,

2010-11-01

This report offers examples of real-world applications and technical progress of hydrogen and fuel cell technologies, including policies adopted by countries to increase technology development and commercialization.

Hydrogen production and purification for fuel cell applications

Science.gov (United States)

Chin, Soo Yin

The increased utilization of proton-exchange membrane (PEM) fuel cells as an alternative to internal combustion engines is expected to increase the demand for hydrogen, which is used as the energy source in these systems. Currently, production of hydrogen for fuel cells is primarily achieved via steam reforming, partial oxidation or autothermal reforming of natural gas, or steam reforming of methanol. However, in all of these processes CO is a by-product that must be subsequently removed due to its adverse effects on the Pt-based electrocatalysts of the PEM fuel cell. Our efforts have focused on production of CO-free hydrogen via catalytic decomposition of hydrocarbons and purification of H2 via the preferential oxidation of CO. The catalytic decomposition of hydrocarbons is an attractive alternative for the production of H2. Previous studies utilizing methane have shown that this approach can indeed produce CO-free hydrogen, with filamentous carbon formed as the by-product and deposited on the catalyst. We have further extended this approach to the decomposition of ethane. In addition to hydrogen and filamentous carbon however, methane is also formed in this case as a by-product. Studies conducted at different temperatures and space velocities suggest that hydrogen is the primary product while methane is formed in a secondary step. Ni/SiO2 catalysts are active for ethane decomposition at temperatures above 500°C. Although the yield of hydrogen increases with temperature, the catalyst deactivation rate also accelerates at higher temperatures. The preferential oxidation of CO is currently used for the purification of CO-contaminated hydrogen streams due to its efficiency and simplicity. Conventional Pt catalysts used for this reaction have been shown to effectively remove CO, but have limited selectivity (i.e., substantial amounts of H 2 also react with O2). Our work focused on alternative catalytic materials, such as Ru and bimetallic Ru-based catalysts (Pt-Ru, Ru

Hydrogen Storage Experiments for an Undergraduate Laboratory Course--Clean Energy: Hydrogen/Fuel Cells

Science.gov (United States)

Bailey, Alla; Andrews, Lisa; Khot, Ameya; Rubin, Lea; Young, Jun; Allston, Thomas D.; Takacs, Gerald A.

2015-01-01

Global interest in both renewable energies and reduction in emission levels has placed increasing attention on hydrogen-based fuel cells that avoid harm to the environment by releasing only water as a byproduct. Therefore, there is a critical need for education and workforce development in clean energy technologies. A new undergraduate laboratory…

Development of performance model and optimization strategy for standalone operation of CPV-hydrogen system utilizing multi-junction solar cell

KAUST Repository

Burhan, Muhammad; Shahzad, Muhammad Wakil; Ng, Kim Choon

2017-01-01

Despite highest energy potential, solar energy is only available during diurnal period with varying intensity. Therefore, owing to solar intermittency, solar energy systems need to operate in standalone configuration for steady power supply which requires reliable and sustainable energy storage. Hydrogen production has proved to be the most reliable and sustainable energy storage option for medium and long term operation. However, at the first priority, solar energy must be captured with high efficiency, in order to reduce the overall size of the system and energy storage. Multi-junction solar cells (MJCs) provide highest energy efficiency among all of the photovoltaic technologies and the concentrated photovoltaic (CPV) system concept makes their use cost effective. However, literature is lacking the performance model and optimization strategy for standalone operation of the CPV-hydrogen system. In addition, there is no commercial tool available that can analyze CPV performance, utilizing multi-junction solar cell. This paper proposes the performance model for the CPV-hydrogen systems and the multi-objective optimization strategy for its standalone operation and techno-economic analysis, using micro genetic algorithm (micro-GA). The electrolytic hydrogen production with compression storage and fuel cell, is used as energy storage system. The CPV model is verified for the experimental data of InGaP/InGaAs/Ge triple junction solar cell. An optimal CPV system design is provided for uninterrupted power supply, even under seasonal weather variations. Such approach can be easily integrated with commercial tools and the presented performance data can be used for the design of individual components of the system.

Development of performance model and optimization strategy for standalone operation of CPV-hydrogen system utilizing multi-junction solar cell

KAUST Repository

Burhan, Muhammad

2017-09-16

Despite highest energy potential, solar energy is only available during diurnal period with varying intensity. Therefore, owing to solar intermittency, solar energy systems need to operate in standalone configuration for steady power supply which requires reliable and sustainable energy storage. Hydrogen production has proved to be the most reliable and sustainable energy storage option for medium and long term operation. However, at the first priority, solar energy must be captured with high efficiency, in order to reduce the overall size of the system and energy storage. Multi-junction solar cells (MJCs) provide highest energy efficiency among all of the photovoltaic technologies and the concentrated photovoltaic (CPV) system concept makes their use cost effective. However, literature is lacking the performance model and optimization strategy for standalone operation of the CPV-hydrogen system. In addition, there is no commercial tool available that can analyze CPV performance, utilizing multi-junction solar cell. This paper proposes the performance model for the CPV-hydrogen systems and the multi-objective optimization strategy for its standalone operation and techno-economic analysis, using micro genetic algorithm (micro-GA). The electrolytic hydrogen production with compression storage and fuel cell, is used as energy storage system. The CPV model is verified for the experimental data of InGaP/InGaAs/Ge triple junction solar cell. An optimal CPV system design is provided for uninterrupted power supply, even under seasonal weather variations. Such approach can be easily integrated with commercial tools and the presented performance data can be used for the design of individual components of the system.

Project Profile: Hydrogen Fuel Cell Mobile Lighting Tower (HFCML)

Science.gov (United States)

McLaughlin, Russell

2013-01-01

NASA is committed to finding innovative solutions that improve the operational performance of ground support equipment while providing environment and cost benefits, as well. Through the Hydrogen Fuel Cell Mobile Lighting Tower (HFCML) project, NASA gained operational exposure to a novel application of high efficiency technologies. Traditionally, outdoor lighting and auxiliary power at security gates, launch viewing sites, fallback areas, outage support, and special events is provided by diesel generators with metal halide lights. Diesel generators inherently contribute to C02, NOx, particulate emissions, and are very noisy. In 2010, engineers from NASA's Technology Evaluation for Environmental Risk Mitigation Principal Center (TEERM) introduced KSC operations to a novel technology for outdoor lighting needs. Developed by a team led by Sandia National Laboratory (SNL), the technology pairs a 5kW hydrogen fuel cell with robust high efficiency plasma lights in a towable trailer. Increased efficiency, in both the fuel cell power source and lighting load, yields longer run times between fueling operations while providing greater auxiliary power. Because of the unit's quiet operation and no exhaust fumes, it is capable of being used indoors and in emergency situations, and meets the needs of all other operational roles for metal halide/diesel generators. The only discharge is some water and warm air. Environmental benefits include elimination of diesel particulate emissions and estimated 73% greenhouse gas emissions savings when the hydrogen source is natural gas (per GREET model). As the technology matures the costs could become competitive for the fuel cell units which are approximately 5 times diesel units. Initial operational . concerns included the hydrogen storage tanks and valves, lightning safety/grounding, and required operating and refueling procedures. TEERM facilitated technical information exchange (design drawings, technical standards, and operations

A procedure for reducing the concentration of hydrogen ions in acid anionic eluate and equipment therefore

International Nuclear Information System (INIS)

Parobek, P.; Baloun, S.; Plevac, S.

1989-01-01

The method is described of reducing the concentration of hydrogen ions in acid anionic eluate produced in the separation of uranium or other metals, in which anion exchanger elution, precipitation, filtration and precipitate and anion exchanger washing are used. The technological line for such elution comprises at least one ion exchange column and at least one container. They together form the first and the second stages of preparation of the acid anion elution solution, the sorption-elution separation of hydrogen ions on an cation exchanger being inserted between them. The preparation of the solution is divide into two stages. In the first stage, the acid and part of the solution for the preparation of the acid anion elution solution are supplied. The resulting enriched acid elution solution is fe onto the cation exchanger where the hydrogen ion concentration i reduced. It is then carried into the second stage where it is mixed with the remaining part of the solution. (B.S.)

Hydrogen production from formic acid in pH-stat fed-batch operation for direct supply to fuel cell.

Science.gov (United States)

Shin, Jong-Hwan; Yoon, Jong Hyun; Lee, Seung Hoon; Park, Tai Hyun

2010-01-01

Enterobacter asburiae SNU-1 harvested after cultivation was used as a whole cell biocatalyst, for the production of hydrogen. Formic acid was efficiently converted to hydrogen using the harvested cells with an initial hydrogen production rate and total hydrogen production of 491 ml/l/h and 6668 ml/l, respectively, when 1 g/l of whole cell enzyme was used. Moreover, new pH-stat fed-batch operation was conducted, and total hydrogen production was 1.4 times higher than that of batch operation. For practical application, bio-hydrogen produced from formic acid using harvested cells was directly applied to PEMFC for power generation.

Research and Development of a PEM Fuel Cell, Hydrogen Reformer, and Vehicle Refueling Facility

Energy Technology Data Exchange (ETDEWEB)

Edward F. Kiczek

2007-08-31

Air Products and Chemicals, Inc. has teamed with Plug Power, Inc. of Latham, NY, and the City of Las Vegas, NV, to develop, design, procure, install and operate an on-site hydrogen generation system, an alternative vehicle refueling system, and a stationary hydrogen fuel cell power plant, located in Las Vegas. The facility will become the benchmark for validating new natural gas-based hydrogen systems, PEM fuel cell power generation systems, and numerous new technologies for the safe and reliable delivery of hydrogen as a fuel to vehicles. Most important, this facility will serve as a demonstration of hydrogen as a safe and clean energy alternative. Las Vegas provides an excellent real-world performance and durability testing environment.

Development of Sensors and Sensing Technology for Hydrogen Fuel Cell Vehicle Applications

Energy Technology Data Exchange (ETDEWEB)

Brosha, E L; Sekhar, P K; Mukundan, R; Williamson, T; Garzon, F H; Woo, L Y; Glass, R R

2010-01-06

One related area of hydrogen fuel cell vehicle (FCV) development that cannot be overlooked is the anticipated requirement for new sensors for both the monitoring and control of the fuel cell's systems and for those devices that will be required for safety. Present day automobiles have dozens of sensors on-board including those for IC engine management/control, sensors for state-of-health monitoring/control of emissions systems, sensors for control of active safety systems, sensors for triggering passive safety systems, and sensors for more mundane tasks such as fluids level monitoring to name the more obvious. The number of sensors continues to grow every few years as a result of safety mandates but also in response to consumer demands for new conveniences and safety features. Some of these devices (e.g. yaw sensors for dynamic stability control systems or tire presure warning RF-based devices) may be used on fuel cell vehicles without any modification. However the use of hydrogen as a fuel will dictate the development of completely new technologies for such requirements as the detection of hydrogen leaks, sensors and systems to continuously monitor hydrogen fuel purity and protect the fuel cell stack from poisoning, and for the important, yet often taken for granted, tasks such as determining the state of charge of the hydrogen fuel storage and delivery system. Two such sensors that rely on different transduction mechanisms will be highlighted in this presentation. The first is an electrochemical device for monitoring hydrogen levels in air. The other technology covered in this work, is an acoustic-based approach to determine the state of charge of a hydride storage system.

Modeling the performance of hydrogen-oxygen unitized regenerative proton exchange membrane fuel cells for energy storage

Science.gov (United States)

Guarnieri, Massimo; Alotto, Piergiorgio; Moro, Federico

2015-11-01

Thanks to the independent sizing of power and energy, hydrogen-based energy storage is one of the very few technologies capable of providing long operational times in addition to the other advantages offered by electrochemical energy storage, for example scalability, site versatility, and mobile service. The typical design consists of an electrolyzer in charge mode and a separate fuel cell in discharge mode. Instead, a unitized regenerative fuel cell (URFC) is a single device performing both energy conversions, achieving a higher compactness and power-to-weight ratio. This paper presents a performance model of a URFC based on a proton exchange membrane (PEM) electrolyte and working on hydrogen and oxygen, which can provide high energy and power densities (>0.7 W cm-2). It provides voltage, power, and efficiency at varying load conditions as functions of the controlling physical quantities: temperature, pressure, concentration, and humidification. The model constitutes a tool for designing the interface and control sub-system as well as for exploring optimized cell/stack designs and operational conditions. To date, only a few of such analyses have been carried out and more research is needed in order to explore the true potential of URFCs.

Effect of low-energy hydrogen ion implantation on dendritic web silicon solar cells

Science.gov (United States)

Rohatgi, A.; Meier, D. L.; Rai-Choudhury, P.; Fonash, S. J.; Singh, R.

1986-01-01

The effect of a low-energy (0.4 keV), short-time (2-min), heavy-dose (10 to the 18th/sq cm) hydrogen ion implant on dendritic web silicon solar cells and material was investigated. Such an implant was observed to improve the cell open-circuit voltage and short-circuit current appreciably for a number of cells. In spite of the low implant energy, measurements of internal quantum efficiency indicate that it is the base of the cell, rather than the emitter, which benefits from the hydrogen implant. This is supported by the observation that the measured minority-carrier diffusion length in the base did not change when the emitter was removed. In some cases, a threefold increase of the base diffusion length was observed after implantation. The effects of the hydrogen implantation were not changed by a thermal stress test at 250 C for 111 h in nitrogen. It is speculated that hydrogen enters the bulk by traveling along dislocations, as proposed recently for edge-defined film-fed growth silicon ribbon.

Long term hydrogen production potential of concentrated photovoltaic (CPV) system in tropical weather of Singapore

KAUST Repository

Burhan, Muhammad

2016-08-23

Concentrated photovoltaic (CPV) system provides highest solar energy conversion efficiency among all the photovoltaic technologies and provides the most suitable option to convert solar energy into hydrogen, as future sustainable energy carrier. So far, only conventional flat plate PV systems are being used for almost all of the commercial applications. However, most of the studies have only shown the maximum efficiency of hydrogen production using CPV. In actual field conditions, the performance of CPV-Hydrogen system is affected by many parameter and it changes continuously during whole day operation. In this paper, the daily average and long term performances are proposed to analyze the real field potential of the CPV-Hydrogen system, which is of main interest for designers and consumers. An experimental setup is developed and a performance model is proposed to investigate the average and long term production potential of CPV-Hydrogen system. The study is carried out in tropical weather of Singapore. The maximum CPV efficiency of 27-28% and solar to hydrogen (STH) efficiency of 18%, were recorded. In addition, the CPV-Hydrogen system showed the long term average efficiency of 15.5%, for period of one year (12-months), with electrolyser rating of 47 kWh/kg and STH production potential of 218 kWh/kg. Based upon the DNI availability, the system showed hydrogen production potential of 0.153-0.553 kg/m/month, with average production of 0.43 kg/m/month. However, CPV-Hydrogen system has shown annual hydrogen production potential of 5.162 kg/m/year in tropical weather of Singapore.

Influence of the concentration of borohydride towards hydrogen production and escape for borohydride oxidation reaction on Pt and Au electrodes - experimental and modelling insights

Science.gov (United States)

Olu, Pierre-Yves; Bonnefont, Antoine; Braesch, Guillaume; Martin, Vincent; Savinova, Elena R.; Chatenet, Marian

2018-01-01

The Borohydride Oxidation Reaction (BOR), the anode reaction in a Direct borohydride fuel cell (DBFC), is complex and still poorly understood, which impedes the development and deployment of the DBFC technology. In particular, no practical electrocatalyst is capable to prevent gaseous hydrogen generation and escape from its anode upon operation, which lowers the fuel-efficiency of the DBFC and raises safety issues in operation. The nature of the anode electrocatalysts strongly influences the hydrogen escape characteristics of the DBFC, which demonstrates how important it is to isolate the BOR mechanism in conditions relevant to DBFC operation. In this paper, from a selected literature review and BOR experiments performed in differential electrochemical mass spectrometry (DEMS) in a wide range of NaBH4 concentration (5-500 mM), a microkinetic model of the BOR for both Pt and Au surfaces is proposed; this model takes into account the hydrogen generation and escape.

Novel Methods of Hydrogen Leak Detection

International Nuclear Information System (INIS)

Pushpinder S Puri

2006-01-01

For hydrogen to become a consumer fuel for automotive and domestic power generation, safety is paramount. Today's hydrogen systems are built with inherent safety measures and multiple levels of protection. However, human senses, in particular, the sense of smell, is considered the ultimate safeguards against leaks. Since hydrogen is an odorless gas, use of odorants to detect leaks, as is done in case of natural gas, is obvious solution. The odorants required for hydrogen used in fuel cells have a unique requirement which must be met. This is because almost all of the commercial odorants used in gas leak detection contain sulfur which acts as poison for the catalysts used in hydrogen based fuel cells, most specifically for the PEM (polymer electrolyte membrane or proton exchange membrane) fuel cells. A possible solution to this problem is to use non-sulfur containing odorants. Chemical compounds based on mixtures of acrylic acid and nitrogen compounds have been adopted to achieve a sulfur-free odorization of a gas. It is, therefore, desired to have a method and system for hydrogen leak detection using odorant which can incorporate a uniform concentration of odorant in the hydrogen gas, when odorants are mixed in the hydrogen storage or delivery means. It is also desired to develop methods where the odorant is not added to the bulk hydrogen, keeping it free of the odorization additives. A series of novel solutions are proposed which address the issues raised above. These solutions are divided into three categories as follows: 1. Methods incorporating an odorant in the path of hydrogen leak as opposed to adding it to the hydrogen gas. 2. Methods where odorants are generated in-situ by chemical reaction with the leaking hydrogen 3. Methods of dispensing and storing odorants in high pressure hydrogen gas which release odorants to the gas at a uniform and predetermined rates. Use of one or more of the methods described here in conjunction with appropriate engineering

Reversible transient hydrogen storage in a fuel cell-supercapacitor hybrid device.

Science.gov (United States)

Unda, Jesus E Zerpa; Roduner, Emil

2012-03-21

A new concept is investigated for hydrogen storage in a supercapacitor based on large-surface-area carbon material (Black Pearls 2000). Protons and electrons of hydrogen are separated on a fuel cell-type electrode and then stored separately in the electrical double layer, the electrons on the carbon and the protons in the aqueous electrolyte of the supercapacitor electrode. The merit of this concept is that it works spontaneously and reversibly near ambient pressure and temperature. This is in pronounced contrast to what has been known as electrochemical hydrogen storage, which does not involve hydrogen gas and where electrical work has to be spent in the loading process. With the present hybrid device, a H(2) storage capacity of 0.13 wt% was obtained, one order of magnitude more than what can be stored by conventional physisorption on large-surface-area carbons at the same pressure and temperature. Raising the pressure from 1.5 to 3.5 bar increased the capacity by less than 20%, indicating saturation. A capacitance of 11 μF cm(-2), comparable with that of a commercial double layer supercapacitor, was found using H(2)SO(4) as electrolyte. The chemical energy of the stored H(2) is almost a factor of 3 larger than the electrical energy stored in the supercapacitor. Further developments of this concept relate to a hydrogen buffer integrated inside a proton exchange membrane fuel cell to be used in case of peak power demand. This serial setup takes advantage of the suggested novel concept of hydrogen storage. It is fundamentally different from previous ways of operating a conventional supercapacitor hooked up in parallel to a fuel cell.

Solutions to commercializing metal hydride hydrogen storage products

International Nuclear Information System (INIS)

Tomlinson, J.J.; Belanger, R.

2004-01-01

'Full text:' Whilst the concept of a Hydrogen economy in the broad sense may for some analysts and Fuel Cell technology developers be an ever moving target the use of hydrogen exists and is growing in other markets today. The use of hydrogen is increasing. Who are the users? What are their unique needs? How can they better be served? As the use of hydrogen increases there are things we can do to improve the perception and handling of hydrogen as an industrial gas that will impact the future issues of hydrogen as a fuel thereby assisting the mainstream availability of hydrogen fuel a reality. Factors that will induce change in the way hydrogen is used, handled, transported and stored are the factors to concentrate development efforts on. Other factors include: cost; availability; safety; codes and standards; and regulatory authorities acceptance of new codes and standards. New methods of storage and new devices in which the hydrogen is stored will influence and bring about change and increased use. New innovative products based on Metal Hydride hydrogen storage will address some of the barriers to widely distributed hydrogen as a fuel or energy carrier to which successful fuel cell product commercialization is subject. Palcan has developed innovative products based on it's Rare Earth Metal Hydride alloy. Some of these innovations will aid the distribution of hydrogen as a fuel and offer alternatives to the existing hydrogen user and to the Fuel Cell product developer. An overview of the products and how these products will affect the distribution and use of hydrogen as an industrial gas and fuel is presented. (author)

Power generation in fuel cells using liquid methanol and hydrogen peroxide

Science.gov (United States)

Narayanan, Sekharipuram R. (Inventor); Valdez, Thomas I. (Inventor); Chun, William (Inventor)

2002-01-01

The invention is directed to an encapsulated fuel cell including a methanol source that feeds liquid methanol (CH.sub.3 OH) to an anode. The anode is electrical communication with a load that provides electrical power. The fuel cell also includes a hydrogen peroxide source that feeds liquid hydrogen peroxide (H.sub.2 O.sub.2) to the cathode. The cathode is also in communication with the electrical load. The anode and cathode are in contact with and separated by a proton-conducting polymer electrolyte membrane.

Role of Nuclear Based Techniques in Development and Characterization of Materials for Hydrogen Storage and Fuel Cells

International Nuclear Information System (INIS)

2012-02-01

materials studied by a combination of complementary methods was presented by a team from the Joint Research Centre of European Commission, which was in charge of coordination work among various research groups from France, Germany and the United Kingdom. They reported effective combination of neutron, X ray and other analytical nuclear techniques as well as a brief comparison of the advantages and limitations of individual methods. Special emphasis was given to characterization of the microstructural changes and thin films made by available nuclear methods, such as positron annihilation spectroscopy and neutron reflectometry. The following report by Chinese researchers, gave a short update on hydrogen absorption properties of lanthanum and zirconium- based hydrogen storage materials. Argentinean and Croatian scientists reported on the degradation of a PEM, fuel cell, platinum-based catalyst by PIXE and application of ERDA methods for imaging of hydrogen-implanted silicon, respectively. The investigation of irradiation effects on oxygen, water and CO 2 desorption, and the identification of phase-transformation behavior on increasing temperature were also discussed. A short overview of structural transformations in Fullerite C 60 due to hydrogenation was reported by Ukrainian researchers. Finally, the study of proton conductors, irradiated by neutrons was presented by the Kazakhstani research team. Briefly discussed was the problem of proton conducting ceramics and the hydrogen concentration profile using ion beam analysis to probe the relationship between microstructure and hydrogen diffusion. Generally, this publication aims to contribute to the dissemination of information regarding practical application of nuclear based techniques in research related to R and D initiatives on hydrogen based energy systems, in particular conversion and storage technologies. (author)

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

The solid molecular hydrogens in the ordered state as function of density and ortho-para concentration: a far infrared study

International Nuclear Information System (INIS)

Jochemsen, R.

1978-01-01

In this thesis, the results of far infrared absorption experiments on solid molecular hydrogen and deuterium are presented. In Chapter I an introduction to the properties of solid molecular hydrogens in given. The experimental system used for the high pressure infrared measurements and the data handling procedures are discussed in Chapter II. The theory of infrared absorption and the averaging of the dipole moment over the motion of the molecules is contained in Chapter III. In this chapter a general sum rule for the integrated absorption is derived. The remaining chapters present the results of the measurements and the discussion. In Chapter IV the author concentrates on the phonon frequencies as a function of ortho-para concentration and density, while in Chapter V measuremtns of phonon lineshape and integrated absorption intensities are presented. Finally, in Chapter VI, a study is given of the phase transition in solid hydrogen and deuterium. This study provides accurate values for the transition temperature as a function of density (in deuterium) and as a function of ortho-para concentration (in hydrogen) as well as the dependence of the order parameter on the temperature and the ortho-para concentration. (Auth.)

A mathematical approach for evaluating nickel-hydrogen cells

Science.gov (United States)

Leibecki, H. F.

1986-01-01

A mathematical equation is presented which gives a quantitative relationship between time-voltage discharge curves, when a cell's ampere-hour capacity is determined at a constant discharge current. In particular the equation quantifies the initial exponential voltage decay; the rate of voltage decay; the overall voltage shift of the curve and the total capacity of the cell at the given discharge current. The results of 12 nickel-hydrogen boiler plate cells cycled to 80 percent depth-of-discharge (DOD) are discussed in association with these equations.

The hydrogen; L'hydrogene

Energy Technology Data Exchange (ETDEWEB)

NONE

2004-07-01

The hydrogen as an energy system represents nowadays a main challenge (in a scientific, economical and environmental point of view). The physical and chemical characteristics of hydrogen are at first given. Then, the challenges of an hydrogen economy are explained. The different possibilities of hydrogen production are described as well as the distribution systems and the different possibilities of hydrogen storage. Several fuel cells are at last presented: PEMFC, DMFC and SOFC. (O.M.)

Hydrogen Production Performance of a 10-Cell Planar Solid-Oxide Electrolysis Stack

International Nuclear Information System (INIS)

James O'Brien; Carl Stoots; Steve Herring; J. Hartvigsen

2005-01-01

An experimental study is under way to assess the performance of solid-oxide cells operating in the steam electrolysis mode for hydrogen production over a temperature range of 800 to 900 C. Results presented in this paper were obtained from a ten-cell planar electrolysis stack, with an active area of 64 cm2 per cell. The electrolysis cells are electrolyte supported, with scandia-stabilized zirconia electrolytes (∼140 (micro)m thick), nickel-cermet steam/hydrogen electrodes, and manganite air-side electrodes. The metallic interconnect plates are fabricated from ferritic stainless steel. The experiments were performed over a range of steam inlet mole fractions (0.1-0.6), gas flow rates (1000-4000 sccm), and current densities (0 to 0.38 A/cm2). Steam consumption rates associated with electrolysis were measured directly using inlet and outlet dewpoint instrumentation. Cell operating potentials and cell current were varied using a programmable power supply. Hydrogen production rates up to 100 Normal liters per hour were demonstrated. Values of area-specific resistance and stack internal temperatures are presented as a function of current density. Stack performance is shown to be dependent on inlet steam flow rate

Bio-hydrogen production by Enterobacter asburiae SNU-1 isolated from a landfill

Energy Technology Data Exchange (ETDEWEB)

Jong-Hwan Shin; Jong Hyun Yoon; Tai Hyun Park [School of Chemical and Biological Engineering, Seoul National University, Seoul 151-744, (Korea, Republic of)

2006-07-01

A new fermentative hydrogen-producing bacterium was isolated from a landfill, and it was identified as Enterobacter asburiae strain using a genomic DNA hybridization method. Environmental factors and metabolic flux influencing the hydrogen production were investigated, including pH, initial glucose and formate concentrations. The major hydrogen production pathway of this strain is considered to be a formate pathway by using formate hydrogen lyase (FHL). Optimum pH for the hydrogen production was pH 7.0 in PYG medium, at which hydrogen production/unit volume and overall hydrogen productivity were 2615 ml/l and 174 ml H{sub 2}/l/hr, respectively, at 25 g glucose/l. The maximum hydrogen productivity was estimated to be 417 ml H{sub 2}/l/hr at 15 g glucose/l. This strain produced bio-hydrogen mostly in the stationary phase, in which formate concentration was high. In this paper, hydrogen production was tried in formate medium after cell harvest. (authors)

Bio-hydrogen production by Enterobacter asburiae SNU-1 isolated from a landfill

International Nuclear Information System (INIS)

Jong-Hwan Shin; Jong Hyun Yoon; Tai Hyun Park

2006-01-01

A new fermentative hydrogen-producing bacterium was isolated from a landfill, and it was identified as Enterobacter asburiae strain using a genomic DNA hybridization method. Environmental factors and metabolic flux influencing the hydrogen production were investigated, including pH, initial glucose and formate concentrations. The major hydrogen production pathway of this strain is considered to be a formate pathway by using formate hydrogen lyase (FHL). Optimum pH for the hydrogen production was pH 7.0 in PYG medium, at which hydrogen production/unit volume and overall hydrogen productivity were 2615 ml/l and 174 ml H 2 /l/hr, respectively, at 25 g glucose/l. The maximum hydrogen productivity was estimated to be 417 ml H 2 /l/hr at 15 g glucose/l. This strain produced bio-hydrogen mostly in the stationary phase, in which formate concentration was high. In this paper, hydrogen production was tried in formate medium after cell harvest. (authors)

The policy framework for the promotion of hydrogen and fuel cells in Europe. A critical assessment

International Nuclear Information System (INIS)

Bleischwitz, Raimund; Bader, Nikolas

2010-01-01

This paper reviews the current EU policy framework in view of its impact on hydrogen and fuel cell development. It screens EU energy policies, EU regulatory policies and EU spending policies. Key questions addressed are as follows: to what extent is the current policy framework conducive to hydrogen and fuel cell development? What barriers and inconsistencies can be identified? How can policies potentially promote hydrogen and fuel cells in Europe, taking into account the complex evolution of such a potentially disruptive technology? How should the EU policy framework be reformed in view of a strengthened and more coherent approach towards full deployment, taking into account recent technology-support activities? This paper concludes that the current EU policy framework does not hinder hydrogen development. Yet it does not constitute a strong push factor either. EU energy policies have the strongest impact on hydrogen and fuel cell development even though their potential is still underexploited. Regulatory policies have a weak but positive impact on hydrogen. EU spending policies show some inconsistencies. However, the large-scale market development of hydrogen and fuel cells will require a new policy approach which comprises technology-specific support as well as a supportive policy framework with a special regional dimension. (author)

Effect of substrate concentration on fermentative hydrogen production from sweet sorghum extract

DEFF Research Database (Denmark)

Antonopoulou, G; Gavala, Hariklia N.; Skiadas, Ioannis

2011-01-01

9895 to 20990 mg/L, in glucose equivalents. The maximum hydrogen production rate and yield were obtained at the concentration of 17000 mg carbohydrates/L and were 2.93 ± 0.09 L H2 /L reactor /d and 0.74 ± 0.02 mol H2 / mol glucose consumed or 8.81 ± 0.02 LH2 / kg sweet sorghum, respectively. The main...

Dynamic behaviour of Li batteries in hydrogen fuel cell power trains

Science.gov (United States)

Veneri, O.; Migliardini, F.; Capasso, C.; Corbo, P.

A Li ion polymer battery pack for road vehicles (48 V, 20 Ah) was tested by charging/discharging tests at different current values, in order to evaluate its performance in comparison with a conventional Pb acid battery pack. The comparative analysis was also performed integrating the two storage systems in a hydrogen fuel cell power train for moped applications. The propulsion system comprised a fuel cell generator based on a 2.5 kW polymeric electrolyte membrane (PEM) stack, fuelled with compressed hydrogen, an electric drive of 1.8 kW as nominal power, of the same typology of that installed on commercial electric scooters (brushless electric machine and controlled bidirectional inverter). The power train was characterized making use of a test bench able to simulate the vehicle behaviour and road characteristics on driving cycles with different acceleration/deceleration rates and lengths. The power flows between fuel cell system, electric energy storage system and electric drive during the different cycles were analyzed, evidencing the effect of high battery currents on the vehicle driving range. The use of Li batteries in the fuel cell power train, adopting a range extender configuration, determined a hydrogen consumption lower than the correspondent Pb battery/fuel cell hybrid vehicle, with a major flexibility in the power management.

Experimental results and analysis on hydrogen combustion

International Nuclear Information System (INIS)

Dorofeev, S.B.; Efimenko, A.A.; Kochurko, A.S.; Sidorov, V.P.; Bezmelnitsin, A.V.

1994-01-01

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

Novel Composite Hydrogen-Permeable Membranes for Nonthermal Plasma Reactors for the Decomposition of Hydrogen Sulfide

Energy Technology Data Exchange (ETDEWEB)

Morris Argyle; John Ackerman; Suresh Muknahallipatna; Jerry Hamann; Stanislaw Legowski; Gui-Bing Zhao; Sanil John; Ji-Jun Zhang; Linna Wang

2007-09-30

The goal of this experimental project was to design and fabricate a reactor and membrane test cell to dissociate hydrogen sulfide (H{sub 2}S) in a nonthermal plasma and to recover hydrogen (H{sub 2}) through a superpermeable multi-layer membrane. Superpermeability of hydrogen atoms (H) has been reported by some researchers using membranes made of Group V transition metals (niobium, tantalum, vanadium, and their alloys), but it was not achieved at the moderate pressure conditions used in this study. However, H{sub 2}S was successfully decomposed at energy efficiencies higher than any other reports for the high H{sub 2}S concentration and moderate pressures (corresponding to high reactor throughputs) used in this study.

Concentrator-solar-cell development

Science.gov (United States)

Grenon, L.

1982-07-01

A program is described which is a continuation of earlier programs for the development of high-efficiency, low-cost, silicon concentrator solar cells. The base-line process steps and process sequences identified in these earlier contracts were evaluated and specific processes reviewed. In particular, emphasis on the use of Czochralski-grown silicon wafers rather than float-zone wafers were examined. Additionally, a study of the trade-offs between textured and nontextured cells was initiated, and the limits within which the low-cost plated nickel copper metallization can be used in concentrator solar cell applications was identified.

The liquid hydrogen cell in the EL3 Saclay reactor; Cellule a hydrogene liquide dans la pile EL3 de Saclay

Energy Technology Data Exchange (ETDEWEB)

Jacrot, B; Lacaze, A; Weil, L [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires; [Grenoble-1 Univ., 38 (France)

1960-07-01

Description and results in connection with the liquid hydrogen cell, for obtaining slow neutrons, in the EL3. (author) [French] Description et resultats concernant la cellule a hydrogene liquide de EL3 utilisee pour obtenir des neutrons lents. (auteur)

Paper-based membraneless hydrogen peroxide fuel cell prepared by micro-fabrication

Science.gov (United States)

Mousavi Ehteshami, Seyyed Mohsen; Asadnia, Mohsen; Tan, Swee Ngin; Chan, Siew Hwa

2016-01-01

A paper-based membraneless single-compartment hydrogen peroxide power source prepared by micro-electromechanical systems (MEMS) technology is reported. The cell utilizes hydrogen peroxide as both fuel and oxidant in a low volume cell fabricated on paper. The fabrication method used is a simple method where precise, small-sized patterns are produced which include the hydrophilic paper bounded by hydrophobic resin. Open circuit potentials of 0.61 V and 0.32 V are achieved for the cells fabricated with Prussian Blue as the cathode and aluminium/nickel as the anode materials, respectively. The power produced by the cells is 0.81 mW cm-2 at 0.26 V and 0.38 mW cm-2 at 0.14 V, respectively, even after the cell is bent or distorted. Such a fuel cell provides an easily fabricated, environmentally friendly, flexible and cost saving power source. The cell may be integrated within a self-sustained diagnostic system to provide the on-demand power for future bio-sensing applications.

Effect of the ethanol concentration in the anode on the direct ethanol fuel cell performance

Energy Technology Data Exchange (ETDEWEB)

Belchor, Pablo Martins; Loeser, Neiva; Forte, Maria Madalena de Camargo [Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS (Brazil); Carpenter, Deyse [Fundacao Universidade Regional de Blumenau (FURB), Blumenau, SC (Brazil)], Email: rafarstv@hotmail.com

2010-07-01

Changes in the climate, sources and development of renewable energy are issues that have gain greater importance, and fuel cells have been investigated as an alternative source to produce energy through electrochemical reactions. Among the fuel cells types the Proton Exchange Membrane (PEMFC), fed with pure hydrogen at the anode and oxygen at the cathode, seen be the more promising ones as an electrolyte for portable, mobile and stationary applications due to its low emissions, low operating temperature, high power density and quick configuration. To avoid inconvenience of storage and transportation of pure hydrogen a PEMFC fed with alcohols has been developed, named Direct Alcohol Fuel Cells (DAFC). One way to increase the performance of DAFC is added water in the alcohol inserted into the anode, because the water keeps the membrane hydrated. In this work, the performance of a DAFC was evaluated by following the loss in the polarization curve and cell power by varying the ethanol/water ratio. The aim of this study was determine the optimal water/ethanol ratio to be feed in a DEFC prototype mounted in the lab. By the results it was possible to point that the best concentration of ethanol aqueous solution for the DEFC tested was around 1 mol.L-1. (author)

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)

Performance optimization of a PEM hydrogen-oxygen fuel cell

OpenAIRE

Maher A.R. Sadiq Al-Baghdadi

2013-01-01

The objective was to develop a semi-empirical model that would simulate the performance of proton exchange membrane (PEM) fuel cells without extensive calculations. A fuel cell mathematical module has been designed and constructed to determine the performance of a PEM fuel cell. The influence of some operating parameters on the performance of PEM fuel cell has been investigated using pure hydrogen on the anode side and oxygen on the cathode side. The present model can be used to investigate t...

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

International Nuclear Information System (INIS)

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

2004-01-01

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

A techno-economic analysis of decentralized electrolytic hydrogen production for fuel cell vehicles

International Nuclear Information System (INIS)

Prince-Richard, S.; Whale, M.; Djilali, N.

2000-01-01

Fueling is a central issue in the development of fuel cell systems, especially for transportation applications. Which fuels will be used to provide the necessary hydrogen and what kind of production / distribution infrastructure will be required are key questions for the large scale market penetration of fuel cell vehicles. Methanol, gasoline and hydrogen are currently the three most seriously considered fuel options. Primarily because of economic considerations, these energy currencies would all be largely produced from fossil fuel sources in the near future. One problem in using fossil fuel sources as a feedstock is their associated emissions, in particular greenhouse gases. This paper presents some elements of a study currently underway to assess the techno-economic prospects of decentralized electrolytic hydrogen production for fuel cell vehicles

Analytic Methods for Benchmarking Hydrogen and Fuel Cell Technologies; NREL (National Renewable Energy Laboratory)

Energy Technology Data Exchange (ETDEWEB)

Melaina, Marc; Saur, Genevieve; Ramsden, Todd; Eichman, Joshua

2015-05-28

This presentation summarizes NREL's hydrogen and fuel cell analysis work in three areas: resource potential, greenhouse gas emissions and cost of delivered energy, and influence of auxiliary revenue streams. NREL's hydrogen and fuel cell analysis projects focus on low-­carbon and economic transportation and stationary fuel cell applications. Analysis tools developed by the lab provide insight into the degree to which bridging markets can strengthen the business case for fuel cell applications.

Critical Filler Concentration in Sulfated Titania-Added Nafion™ Membranes for Fuel Cell Applications

Directory of Open Access Journals (Sweden)

Mirko Sgambetterra

2016-04-01

Full Text Available In this communication we present a detailed study of Nafion™ composite membranes containing different amounts of nanosized sulfated titania particles, synthesized through an optimized one-step synthesis procedure. Functional membrane properties, such as ionic exchange capacity and water uptake (WU ability will be described and discussed, together with thermal analysis, atomic force microscopy and Raman spectroscopy data. Also electrochemical properties such as proton conductivity and performances in hydrogen fuel cells will be presented. It has been demonstrated that a critical concentration of filler particles can boost the fuel cell performance at low humidification, exhibiting a significant improvement of the maximum power and current density delivered under 30% low-relative humidity (RH and 70 °C with respect to bare Nafion™-based systems.

Tailoring Microbial Electrochemical Cells for Production of Hydrogen Peroxide at High Concentrations and Efficiencies.

Science.gov (United States)

Young, Michelle N; Links, Mikaela J; Popat, Sudeep C; Rittmann, Bruce E; Torres, César I

2016-12-08

A microbial peroxide producing cell (MPPC) for H 2 O 2 production at the cathode was systematically optimized with minimal energy input. First, the stability of H 2 O 2 was evaluated using different catholytes, membranes, and catalyst materials. On the basis of these results, a flat-plate MPPC fed continuously using 200 mm NaCl catholyte at a 4 h hydraulic retention time was designed and operated, producing H 2 O 2 for 18 days. H 2 O 2 concentration of 3.1 g L -1 H 2 O 2 with 1.1 Wh g -1 H 2 O 2 power input was achieved in the MPPC. The high H 2 O 2 concentration was a result of the optimum materials selected. The small energy input was largely the result of the 0.5 cm distance between the anode and cathode, which reduced ionic transport losses. However, >50 % of operational overpotentials were due to the 4.5-5 pH unit difference between the anode and cathode chambers. The results demonstrate that a MPPC can continuously produce H 2 O 2 at high concentration by selecting compatible materials and appropriate operating conditions. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

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.

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.

Hydrogen like energy and materials for fuel cells

International Nuclear Information System (INIS)

Fernandez V, S. M.

2010-01-01

The researches on the production, storage and the use of hydrogen like fuel or energy carrying are carried out in several laboratories around the world. In the Instituto Nacional de Investigaciones Nucleares (ININ), from the year of 1993 they are carried out researches about the synthesis of electro-catalysts materials than can serve in the hydrogen production starting from the electrolysis of the water, or in fuel cells, as well as of semiconductor materials for the photo-electrolysis of the water. Recently, in collaboration with other Departments of the ININ, the hydrogen production has been approached starting from fruit and vegetable wastes, with the purpose of evaluating the possibility that this residuals can be utilized for the energy obtaining and that they are not only garbage that causes problems of environmental pollution, generate toxic gases and pollute the soil with the organic acids that take place during their fermentation. (Author)

Hydrogen peroxide kinetics in water radiolysis

Science.gov (United States)

Iwamatsu, Kazuhiro; Sundin, Sara; LaVerne, Jay A.

2018-04-01

The kinetics of the formation and reaction of hydrogen peroxide in the long time γ- radiolysis of water is examined using a combination of experiment with model calculations. Escape yields of hydrogen peroxide on the microsecond time scale are easily measured with added radical scavengers even with substantial amounts of initial added hydrogen peroxide. The γ-radiolysis of aqueous hydrogen peroxide solutions without added radical scavengers reach a steady state limiting concentration of hydrogen peroxide with increasing dose, and that limit is directly proportional to the initial concentration of added hydrogen peroxide. The dose necessary to reach that limiting hydrogen peroxide concentration is also proportional to the initial concentration, but dose rate has a very small effect. The addition of molecular hydrogen to aqueous solutions of hydrogen peroxide leads to a decrease in the high dose limiting hydrogen peroxide concentration that is linear with the initial hydrogen concentration, but the amount of decrease is not stoichiometric. Proton irradiations of solutions with added hydrogen peroxide and hydrogen are more difficult to predict because of the decreased yields of radicals; however, with a substantial increase in dose rate there is a sufficient decrease in radical yields that hydrogen addition has little effect on hydrogen peroxide decay.

Durability of solid oxide electrolysis cells for hydrogen production

Energy Technology Data Exchange (ETDEWEB)

Hauch, A.; Hoejgaard Jensen, S.; Dalgaard Ebbesen, S.

2007-05-15

In the perspective of the increasing interest in renewable energy and hydrogen economy, the reversible solid oxide cells (SOCs) is a promising technology as it has the potential of providing efficient and cost effective hydrogen production by high temperature electrolysis of steam (HTES). Furthermore development of such electrolysis cells can gain from the results obtained within the R and D of SOFCs. For solid oxide electrolysis cells (SOEC) to become interesting from a technological point of view, cells that are reproducible, high performing and long-term stable need to be developed. In this paper we address some of the perspectives of the SOEC technology i.e. issues such as a potential H2 production price as low as 0.71 US dollar/kg H{sub 2} using SOECs for HTES; is there a possible market for the electrolysers? and what R and D steps are needed for the realisation of the SOEC technology? In the experimental part we present electrolysis test results on SOCs that have been optimized for fuel cell operation but applied for HTES. The SOCs are produced on a pre-pilot scale at Risoe National Laboratory. These cells have been shown to have excellent initial electrolysis performance, but the durability of such electrolysis cells are not optimal and examples of results from SOEC tests over several hundreds of hours are given here. The long-term tests have been run at current densities of -0.5 A/cm{sup 2} and -1 A/cm{sup 2}, temperatures of 850 deg. C and 950 deg. C and p(H{sub 2}O)/p(H{sub 2}) of 0.5/0.5 and 0.9/0.1. Long-term degradation rates are shown to be up to 5 times higher for SOECs compared to similar SOFC testing. Furthermore, hydrogen and synthetic fuel production prices are calculated using the experimental results from long-term electrolysis test as input and a short outlook for the future work on SOECs will be given as well. (au)

Effect of the hydrogen concentration on the ductility of Zry-4; Efecto de la concentracion de hidrogeno sobre la ductilidad de Zry-4

Energy Technology Data Exchange (ETDEWEB)

Domizzi, G; Ovejero Garcia, J [Comision Nacional de Energia Atomica, San Martin (Argentina). Unidad de Actividad Materiales

1997-12-31

After many years in service, zirconium alloys employed in nuclear reactors may reach high contents of hydride particles, exceeding the hydrogen solid solubility at the service temperature. The brittle character of zirconium hydride promotes the alloy embrittlement. In order to predict the critical hydrogen concentration which causes a ductile-brittle transition in a Zry-4 foil, 0.02mm thick, tensile test specimens were hydride by gaseous charging. To obtain uniform hydride distribution the specimens were electroplated with a film of copper prior to gaseous charge. In absence of oxide film, the foils retained its ductility up to high hydrogen concentration (950 Og/g). The critical hydrogen concentration was attained at 2900-3100 Og/g. (author). 4 refs., 2 figs., 1 tab.

Evaluation of AECL catalysts for hydrogen fuel-cell applications. Paper no. IGEC-1-073

International Nuclear Information System (INIS)

Li, J.; Suppiah, S.; Li, H.; Kutchcoskie, K.J.; Strikwerda, S.

2005-01-01

AECL has been engaged in the promotion of the nuclear-hydrogen economy, which envisions that hydrogen fuel cells will generate power using hydrogen as fuel produced by nuclear energy. Since AECL's catalysts developed for the production, upgrading and detritiation of heavy water are very similar to commercial fuel-cell catalysts, a program was initiated to evaluate AECL catalysts for fuel-cell applications. As a first step in this effort, a half-cell test facility was set up to characterize the performance of catalysts for hydrogen fuel cells. This paper outlines the results obtained from cathodic reduction of oxygen in a 0.5 M sulphuric acid solution on a rotating disc electrode at 65 o C. The performance of the catalysts was characterized using standard electrochemical methods including cyclic voltammetry, Voltammogram/Tafel plots and short-term stability plots. Several monometallic Pt and Pt-based bimetallic catalysts were tested and compared with a commercially available catalyst for fuel-cell applications. AECL's monometallic Pt catalysts showed comparable or better activities than commercial catalysts with similar Pt loading. An AECL Pt-based bimetallic catalyst has shown superior performance to a monometallic Pt catalyst with similar Pt loading. Evaluation of various catalyst formulations is ongoing on the half-cell facility at AECL. Further investigation of promising catalysts identified from half-cell test is also being carried out in single fuel cell on test stations under normal fuel-cell operating conditions. (author)

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)

Hydrogen and fuel cells: threat or opportunity to power company core business?

International Nuclear Information System (INIS)

Grant, A.

2004-01-01

'Full text:' It is noted that many utilities at this conference will discuss the problems with fuel cells (and the hydrogen economy) that revolve around interconnection of fuel cells as distributed generation resources. Interconnection details, both commercial and technical, are a major market barrier and a key problem for electric utilities as these technologies come to market. However, I would like to offer an opportunity to examine a broader subject area. Specifically, I would submit that one key issue is the need to look at the hydrogen and fuel cell market as a new opportunity for electric utilities. At BC Hydro we see that both the hydrogen market and the fuel cells market are potential threats and potential opportunities for our core business. We therefore believe it is prudent to learn more about these markets and 'learn by doing' by participating in demonstration projects with other partners where we can leverage our investments and spread the risk. In my talk I would like to explore the various elements of the BC Hydro fuel cell activities within this context of an evolving business model for a power utility. (author)

An investigation of hydrogen storage methods for fuel cell operation with man-portable equipment

Energy Technology Data Exchange (ETDEWEB)

Browning, D [Defence Evaluation and Research Agency, Haslar (United Kingdom); Jones, P [Defence Evaluation and Research Agency, Haslar (United Kingdom); Packer, K [Defence Evaluation and Research Agency, Haslar (United Kingdom)

1997-03-01

Air breathing proton exchange membrane fuel cells (PEMFC) are being considered as a power source for man-portable equipment, such as army radios. In addition to the weight and volume of the fuel cell itself, the device producing hydrogen with which to fuel the cell is also of crucial importance. This paper describes a number of hydrogen storage methods and discusses their applicability to man-portable equipment. (orig.)

Steam and partial oxidation reforming options for hydrogen production from fossil fuels for PEM fuel cells

OpenAIRE

Yousri M.A. Welaya; Mohamed M. El Gohary; Nader R. Ammar

2012-01-01

Proton exchange membrane fuel cell (PEM) generates electrical power from air and from hydrogen or hydrogen rich gas mixtures. Therefore, there is an increasing interest in converting current hydrocarbon based marine fuels such as natural gas, gasoline, and diesel into hydrogen rich gases acceptable to the PEM fuel cells on board ships. Using chemical flow sheeting software, the total system efficiency has been calculated. Natural gas appears to be the best fuel for hydrogen rich gas productio...

Hydrogenated indium oxide window layers for high-efficiency Cu(In,Ga)Se{sub 2} solar cells

Energy Technology Data Exchange (ETDEWEB)

Jäger, Timo, E-mail: timo.jaeger@empa.ch; Romanyuk, Yaroslav E.; Nishiwaki, Shiro; Bissig, Benjamin; Pianezzi, Fabian; Fuchs, Peter; Gretener, Christina; Tiwari, Ayodhya N. [Empa – Swiss Federal Laboratories for Materials Science and Technology, Laboratory for Thin Films and Photovoltaics, Überlandstrasse 129, 8600 Dübendorf (Switzerland); Döbeli, Max [ETH Zürich, Swiss Federal Institute of Technology, Laboratory of Ion Beam Physics, Otto-Stern-Weg 5, 8093 Zürich (Switzerland)

2015-05-28

High mobility hydrogenated indium oxide is investigated as a transparent contact for thin film Cu(In,Ga)Se{sub 2} (CIGS) solar cells. Hydrogen doping of In{sub 2}O{sub 3} thin films is achieved by injection of H{sub 2}O water vapor or H{sub 2} gas during the sputter process. As-deposited amorphous In{sub 2}O{sub 3}:H films exhibit a high electron mobility of ∼50 cm{sup 2}/Vs at room temperature. A bulk hydrogen concentration of ∼4 at. % was measured for both optimized H{sub 2}O and H{sub 2}-processed films, although the H{sub 2}O-derived film exhibits a doping gradient as detected by elastic recoil detection analysis. Amorphous IOH films are implemented as front contacts in CIGS based solar cells, and their performance is compared with the reference ZnO:Al electrodes. The most significant feature of IOH containing devices is an enhanced open circuit voltage (V{sub OC}) of ∼20 mV regardless of the doping approach, whereas the short circuit current and fill factor remain the same for the H{sub 2}O case or slightly decrease for H{sub 2}. The overall power conversion efficiency is improved from 15.7% to 16.2% by substituting ZnO:Al with IOH (H{sub 2}O) as front contacts. Finally, stability tests of non-encapsulated solar cells in dry air at 80 °C and constant illumination for 500 h demonstrate a higher stability for IOH-containing devices.

Thermo-hydraulic test of the moderator cell of liquid hydrogen cold neutron source for the Budapest research reactor

International Nuclear Information System (INIS)

Grosz, Tamas; Rosta, Laszlo; Hargitai, Tibor; Mityukhlyaev, V.A.; Serebrov, A.P.; Zaharov, A.A.

1999-01-01

Thermo-hydraulic experiment was carried out in order to test performance of the direct cooled liquid hydrogen moderator cell to be installed at the research reactor of the Budapest Neutron Center. Two electric hearers up to 300 W each imitated the nuclear heat release in the liquid hydrogen as well as in construction material. The test moderator cell was also equipped with temperature gauges to measure the hydrogen temperature at different positions as well as the inlet and outlet temperature of cooling he gas. The hydrogen pressure in the connected buffer volume was also controlled. At 140 w expected total heat load the moderator cell was filled with liquid hydrogen within 4 hours. The heat load and hydrogen pressure characteristics of the moderator cell are also presented. (author)

An overview—Functional nanomaterials for lithium rechargeable batteries, supercapacitors, hydrogen storage, and fuel cells

Energy Technology Data Exchange (ETDEWEB)

Liu, Hua Kun, E-mail: hua@uow.edu.au

2013-12-15

Graphical abstract: Nanomaterials play important role in lithium ion batteries, supercapacitors, hydrogen storage and fuel cells. - Highlights: • Nanomaterials play important role for lithium rechargeable batteries. • Nanostructured materials increase the capacitance of supercapacitors. • Nanostructure improves the hydrogenation/dehydrogenation of hydrogen storage materials. • Nanomaterials enhance the electrocatalytic activity of the catalysts in fuel cells. - Abstract: There is tremendous worldwide interest in functional nanostructured materials, which are the advanced nanotechnology materials with internal or external dimensions on the order of nanometers. Their extremely small dimensions make these materials unique and promising for clean energy applications such as lithium ion batteries, supercapacitors, hydrogen storage, fuel cells, and other applications. This paper will highlight the development of new approaches to study the relationships between the structure and the physical, chemical, and electrochemical properties of functional nanostructured materials. The Energy Materials Research Programme at the Institute for Superconducting and Electronic Materials, the University of Wollongong, has been focused on the synthesis, characterization, and applications of functional nanomaterials, including nanoparticles, nanotubes, nanowires, nanoporous materials, and nanocomposites. The emphases are placed on advanced nanotechnology, design, and control of the composition, morphology, nanostructure, and functionality of the nanomaterials, and on the subsequent applications of these materials to areas including lithium ion batteries, supercapacitors, hydrogen storage, and fuel cells.

An overview—Functional nanomaterials for lithium rechargeable batteries, supercapacitors, hydrogen storage, and fuel cells

International Nuclear Information System (INIS)

Liu, Hua Kun

2013-01-01

Graphical abstract: Nanomaterials play important role in lithium ion batteries, supercapacitors, hydrogen storage and fuel cells. - Highlights: • Nanomaterials play important role for lithium rechargeable batteries. • Nanostructured materials increase the capacitance of supercapacitors. • Nanostructure improves the hydrogenation/dehydrogenation of hydrogen storage materials. • Nanomaterials enhance the electrocatalytic activity of the catalysts in fuel cells. - Abstract: There is tremendous worldwide interest in functional nanostructured materials, which are the advanced nanotechnology materials with internal or external dimensions on the order of nanometers. Their extremely small dimensions make these materials unique and promising for clean energy applications such as lithium ion batteries, supercapacitors, hydrogen storage, fuel cells, and other applications. This paper will highlight the development of new approaches to study the relationships between the structure and the physical, chemical, and electrochemical properties of functional nanostructured materials. The Energy Materials Research Programme at the Institute for Superconducting and Electronic Materials, the University of Wollongong, has been focused on the synthesis, characterization, and applications of functional nanomaterials, including nanoparticles, nanotubes, nanowires, nanoporous materials, and nanocomposites. The emphases are placed on advanced nanotechnology, design, and control of the composition, morphology, nanostructure, and functionality of the nanomaterials, and on the subsequent applications of these materials to areas including lithium ion batteries, supercapacitors, hydrogen storage, and fuel cells

Florida Hydrogen Initiative

Energy Technology Data Exchange (ETDEWEB)

Block, David L

2013-06-30

The Florida Hydrogen Initiative (FHI) was a research, development and demonstration hydrogen and fuel cell program. The FHI program objectives were to develop Florida?s hydrogen and fuel cell infrastructure and to assist DOE in its hydrogen and fuel cell activities The FHI program funded 12 RD&D projects as follows: Hydrogen Refueling Infrastructure and Rental Car Strategies -- L. Lines, Rollins College This project analyzes strategies for Florida's early stage adaptation of hydrogen-powered public transportation. In particular, the report investigates urban and statewide network of refueling stations and the feasibility of establishing a hydrogen rental-car fleet based in Orlando. Methanol Fuel Cell Vehicle Charging Station at Florida Atlantic University ? M. Fuchs, EnerFuel, Inc. The project objectives were to design, and demonstrate a 10 kWnet proton exchange membrane fuel cell stationary power plant operating on methanol, to achieve an electrical energy efficiency of 32% and to demonstrate transient response time of less than 3 milliseconds. Assessment of Public Understanding of the Hydrogen Economy Through Science Center Exhibits, J. Newman, Orlando Science Center The project objective was to design and build an interactive Science Center exhibit called: ?H2Now: the Great Hydrogen Xchange?. On-site Reformation of Diesel Fuel for Hydrogen Fueling Station Applications ? A. Raissi, Florida Solar Energy Center This project developed an on-demand forecourt hydrogen production technology by catalytically converting high-sulfur hydrocarbon fuels to an essentially sulfur-free gas. The removal of sulfur from reformate is critical since most catalysts used for the steam reformation have limited sulfur tolerance. Chemochromic Hydrogen Leak Detectors for Safety Monitoring ? N. Mohajeri and N. Muradov, Florida Solar Energy Center This project developed and demonstrated a cost-effective and highly selective chemochromic (visual) hydrogen leak detector for safety

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

International Nuclear Information System (INIS)

Loyola, V.M.

1982-01-01

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

2011 Annual Progress Report: DOE Hydrogen and Fuel Cells Program (Book)

Energy Technology Data Exchange (ETDEWEB)

2011-11-01

In the past year, the DOE Hydrogen and Fuel Cells Program (the Program) made substantial progress toward its goals and objectives. The Program has conducted comprehensive and focused efforts to enable the widespread commercialization of hydrogen and fuel cell technologies in diverse sectors of the economy. With emphasis on applications that will effectively strengthen our nation's energy security and improve our stewardship of the environment, the Program engages in research, development, and demonstration of critical improvements in the technologies. Highlights of the Program's accomplishments can be found in the sub-program chapters of this report.

Hydrogen production using Rhodopseudomonas palustris WP 3-5 with hydrogen fermentation reactor effluent

International Nuclear Information System (INIS)

Chi-Mei Lee; Kuo-Tsang Hung

2006-01-01

The possibility of utilizing the dark hydrogen fermentation stage effluents for photo hydrogen production using purple non-sulfur bacteria should be elucidated. In the previous experiments, Rhodopseudomonas palustris WP3-5 was proven to efficiently produce hydrogen from the effluent of hydrogen fermentation reactors. The highest hydrogen production rate was obtained at a HRT value of 48 h when feeding a 5 fold effluent dilution from anaerobic hydrogen fermentation. Besides, hydrogen production occurred only when the NH 4 + concentration was below 17 mg-NH 4 + /l. Therefore, for successful fermentation effluent utilization, the most important things were to decrease the optimal HRT, increase the optimal substrate concentration and increase the tolerable ammonia concentration. In this study, a lab-scale serial photo-bioreactor was constructed. The reactor overall hydrogen production efficiency with synthetic wastewater exhibiting an organic acid profile identical to that of anaerobic hydrogen fermentation reactor effluent and with effluent from two anaerobic hydrogen fermentation reactors was evaluated. (authors)

Exergy analysis of components of integrated wind energy / hydrogen / fuel cell

International Nuclear Information System (INIS)

Hernandez Galvez, G.; Pathiyamattom, J.S.; Sanchez Gamboa, S.

2009-01-01

Exergy analysis is made of three components of an integrated wind energy to hydrogen fuel cell: wind turbine, fuel cell (PEMFC) and electrolyzer (PEM). The methodology used to assess how affect the second law efficiency of the electrolyzer and the FC parameters as temperature and operating pressure and membrane thickness. It develop methods to evaluate the influence of changes in the air density and height of the tower on the second law efficiency of the turbine. This work represents a starting point for developing the global availability analysis of an integrated wind / hydrogen / fuel cells, which can be used as a tool to achieve the optimum design of the same. The use of this system contribute to protect the environment

Integrated hydrogen production process from cellulose by combining dark fermentation, microbial fuel cells, and a microbial electrolysis cell

KAUST Repository

Wang, Aijie

2011-03-01

Hydrogen gas production from cellulose was investigated using an integrated hydrogen production process consisting of a dark fermentation reactor and microbial fuel cells (MFCs) as power sources for a microbial electrolysis cell (MEC). Two MFCs (each 25mL) connected in series to an MEC (72mL) produced a maximum of 0.43V using fermentation effluent as a feed, achieving a hydrogen production rate from the MEC of 0.48m 3 H 2/m 3/d (based on the MEC volume), and a yield of 33.2mmol H 2/g COD removed in the MEC. The overall hydrogen production for the integrated system (fermentation, MFC and MEC) was increased by 41% compared with fermentation alone to 14.3mmol H 2/g cellulose, with a total hydrogen production rate of 0.24m 3 H 2/m 3/d and an overall energy recovery efficiency of 23% (based on cellulose removed) without the need for any external electrical energy input. © 2010 Elsevier Ltd.

Integrated hydrogen production process from cellulose by combining dark fermentation, microbial fuel cells, and a microbial electrolysis cell.

Science.gov (United States)

Wang, Aijie; Sun, Dan; Cao, Guangli; Wang, Haoyu; Ren, Nanqi; Wu, Wei-Min; Logan, Bruce E

2011-03-01

Hydrogen gas production from cellulose was investigated using an integrated hydrogen production process consisting of a dark fermentation reactor and microbial fuel cells (MFCs) as power sources for a microbial electrolysis cell (MEC). Two MFCs (each 25 mL) connected in series to an MEC (72 mL) produced a maximum of 0.43 V using fermentation effluent as a feed, achieving a hydrogen production rate from the MEC of 0.48 m(3) H(2)/m(3)/d (based on the MEC volume), and a yield of 33.2 mmol H(2)/g COD removed in the MEC. The overall hydrogen production for the integrated system (fermentation, MFC and MEC) was increased by 41% compared with fermentation alone to 14.3 mmol H(2)/g cellulose, with a total hydrogen production rate of 0.24 m(3) H(2)/m(3)/d and an overall energy recovery efficiency of 23% (based on cellulose removed) without the need for any external electrical energy input. Copyright © 2010 Elsevier Ltd. All rights reserved.

Fuel cell cars in a microgrid for synergies between hydrogen and electricity networks

International Nuclear Information System (INIS)

Alavi, Farid; Park Lee, Esther; Wouw, Nathan van de; De Schutter, Bart; Lukszo, Zofia

2017-01-01

Highlights: • A novel concept of a flexible energy system that uses fuel cell cars as dispatchable power plants. • Synergies between hydrogen and electricity networks by operating of fuel cell cars in a microgrid. • A robust min-max model predictive control scheme for optimal dispatch of the fuel cell cars. • A novel model predictive control scheme to govern the system operation. - Abstract: Fuel cell electric vehicles convert chemical energy of hydrogen into electricity to power their motor. Since cars are used for transport only during a small part of the time, energy stored in the on-board hydrogen tanks of fuel cell vehicles can be used to provide power when cars are parked. In this paper, we present a community microgrid with photovoltaic systems, wind turbines, and fuel cell electric vehicles that are used to provide vehicle-to-grid power when renewable power generation is scarce. Excess renewable power generation is used to produce hydrogen, which is stored in a refilling station. A central control system is designed to operate the system in such a way that the operational costs are minimized. To this end, a hybrid model for the system is derived, in which both the characteristics of the fuel cell vehicles and their traveling schedules are considered. The operational costs of the system are formulated considering the presence of uncertainty in the prediction of the load and renewable energy generation. A robust min-max model predictive control scheme is developed and finally, a case study illustrates the performance of the designed system.

Hydrogen Fuel Cell: Research Progress and Near-Term Opportunities

Science.gov (United States)

2009-04-27

effort brings together automobile and ener- gy companies , as well as their suppliers and other stakeholders, to evaluate light-duty fuel cell vehicles...emissions compared to conventional power technologies. Grocers, banks, tire and hardware companies , logistics providers, and others in the private sector...Term Direct Hydrogen Proton Exchange Membrane (PEM) Fuel Cell Markets, April 2007. 2. Assumptions: Operate 7 hours/shift, 3 shifts/day, 7 days/week

High-energy-density hydrogen-halogen fuel cells for advanced military applications

International Nuclear Information System (INIS)

Balko, E.N.; McElroy, J.F.

1981-01-01

It is pointed out that hydrogen-halogen fuel cell systems are particularly suited for an employment as ground power sources for military applications. The large cell potential and reversible characteristics of the H 2 Cl 2 and H 2 Br 2 couples permit high energy storage density and efficient energy conversion. When used as flow batteries, the fluid nature of the reactants in the hydrogen-halogen systems has several advantages over power sources which involve solid phases. Very deep discharge is possible without degradation of subsequent performance, and energy storage capacity is limited only by the external reactant storage volume. Very rapid chemical recharging is possible through replenishment of the reactant supply. A number of H 2 Cl 2 and H 2 Br 2 fuel cell systems have been studied. These systems use the same solid polymer electrolyte (SPE) cell technology originally developed for H2/O2 fuel cells. The results of the investigation are illustrated with the aid of a number of graphs

High hydrogen production from glycerol or glucose by electrohydrogenesis using microbial electrolysis cells

KAUST Repository

Selembo, Priscilla A.; Perez, Joe M.; Lloyd, Wallis A.; Logan, Bruce E.

2009-01-01

The use of glycerol for hydrogen gas production was examined via electrohydrogenesis using microbial electrolysis cells (MECs). A hydrogen yield of 3.9 mol-H2/mol was obtained using glycerol, which is higher than that possible by fermentation

Removal method of fluorescent dyes as pretreatment for measurement of major ion concentrations and hydrogen and oxygen isotopic ratios

International Nuclear Information System (INIS)

Nakata, Kotaro; Hasegawa, Takuma; Kashiwaya, Koki; Kodama, Hiroki; Miyajima, Tohru

2011-01-01

The major ion concentration and isotope ratio of hydrogen and oxygen can provide important information for migration of groundwater. Sometimes, quantitative estimation of these chemical and isotopic characteristics of solution is necessary for groundwater containing fluorescent dyes, which are used in drilling borehole and tracer experiments. However, sometimes correct estimation is disturbed by dyes and they become a cause of troubles for measurement equipments. Thus development of method to remove dyes is required so that the characteristics of groundwater can be estimated without the negative effect of dyes on measurement or equipments. In this study, removal of four representative dyes (Uranin, Eosin, Naphthalenesulfonic acid sodium(NAP) and Amino G acid potassium salt (AG)) was investigated. Uranin and Eosin were found to be removed by non-ionic synthetic resin: HP2MG. 99.99% of the dyes were removed from initial solutions containing dyes with 10 mg/L after contact with resin, while the contact had little effect on ion concentrations and oxygen and hydrogen isotope ratios. Thus the chemical and isotopic characteristics of groundwater samples containing Uranin and Eosin can be obtained by using the HP2MG resin. On the other hand, the NAP and AG were found to be difficult to remove by the HP2MG resin but they were able to be removed by anion exchange resin (Dowex 1x8). Though contact of solution with Dowex 1x8 did not affect cation concentrations and hydrogen and oxygen isotope ratios, anion concentrations were changed by the contact. Therefore the Dowex 1x8 is only applicable to estimation of the cation concentrations and isotope ratio of hydrogen and oxygen. When both anion and cation concentrations from the samples were necessary, Uranin or Eosin were recommended as a tracer in drilling or tracer experiments. (author)

Feasibility of solid oxide fuel cell dynamic hydrogen coproduction to meet building demand

Science.gov (United States)

Shaffer, Brendan; Brouwer, Jacob

2014-02-01

A dynamic internal reforming-solid oxide fuel cell system model is developed and used to simulate the coproduction of electricity and hydrogen while meeting the measured dynamic load of a typical southern California commercial building. The simulated direct internal reforming-solid oxide fuel cell (DIR-SOFC) system is controlled to become an electrical load following device that well follows the measured building load data (3-s resolution). The feasibility of the DIR-SOFC system to meet the dynamic building demand while co-producing hydrogen is demonstrated. The resulting thermal responses of the system to the electrical load dynamics as well as those dynamics associated with the filling of a hydrogen collection tank are investigated. The DIR-SOFC system model also allows for resolution of the fuel cell species and temperature distributions during these dynamics since thermal gradients are a concern for DIR-SOFC.

Colorimetric detection of endogenous hydrogen sulfide production in living cells

Science.gov (United States)

Ahn, Yong Jin; Lee, Young Ju; Lee, Jaemyeon; Lee, Doyeon; Park, Hun-Kuk; Lee, Gi-Ja

2017-04-01

Hydrogen sulfide (H2S) has received great attention as a third gaseous signal transmitter, following nitric oxide and carbon monoxide. In particular, H2S plays an important role in the regulation of cancer cell biology. Therefore, the detection of endogenous H2S concentrations within biological systems can be helpful to understand the role of gasotransmitters in pathophysiology. Although a simple and inexpensive method for the detection of H2S has been developed, its direct and precise measurement in living cells remains a challenge. In this study, we introduced a simple, facile, and inexpensive colorimetric system for selective H2S detection in living cells using a silver-embedded Nafion/polyvinylpyrrolidone (PVP) membrane. This membrane could be easily applied onto a polystyrene microplate cover. First, we optimized the composition of the coating membrane, such as the PVP/Nafion mixing ratio and AgNO3 concentration, as well as the pH of the Na2S (H2S donor) solution and the reaction time. Next, the in vitro performance of a colorimetric detection assay utilizing the silver/Nafion/PVP membrane was evaluated utilizing a known concentration of Na2S standard solution both at room temperature and at 37 °C in a 5% CO2 incubator. As a result, the sensitivity of the colorimetric assay for H2S at 37 °C in the incubator (0.0056 Abs./μM Na2S, R2 = 0.9948) was similar to that at room temperature (0.0055 Abs./μM Na2S, R2 = 0.9967). Moreover, these assays were less sensitive to interference from compounds such as glutathione, L-cysteine (Cys), and dithiothreitol than to the H2S from Na2S. This assay based on the silver/Nafion/PVP membrane also showed excellent reproducibility (2.8% RSD). Finally, we successfully measured the endogenous H2S concentrations in live C6 glioma cells by s-(5‧-adenosyl)-L-methionine stimulation with and without Cys and L-homocysteine, utilizing the silver/Nafion/PVP membrane. In summary, colorimetric assays using silver

Hydrogen-Induced Plastic Deformation in ZnO

Science.gov (United States)

Lukáč, F.; Čížek, J.; Vlček, M.; Procházka, I.; Anwand, W.; Brauer, G.; Traeger, F.; Rogalla, D.; Becker, H.-W.

In the present work hydrothermally grown ZnO single crystals covered with Pd over-layer were electrochemically loaded with hydrogen and the influence of hydrogen on ZnO micro structure was investigated by positron annihilation spectroscopy (PAS). Nuclear reaction analysis (NRA) was employed for determination of depth profile of hydrogen concentration in the sample. NRA measurements confirmed that a substantial amount of hydrogen was introduced into ZnO by electrochemical charging. The bulk hydrogen concentration in ZnO determined by NRA agrees well with the concentration estimated from the transported charge using the Faraday's law. Moreover, a subsurface region with enhanced hydrogen concentration was found in the loaded crystals. Slow positron implantation spectroscopy (SPIS) investigations of hydrogen-loaded crystal revealed enhanced concentration of defects in the subsurface region. This testifies hydrogen-induced plastic deformation of the loaded crystal. Absorbed hydrogen causes a significant lattice expansion. At low hydrogen concentrations this expansion is accommodated by elastic straining, but at higher concentrations hydrogen-induced stress exceeds the yield stress in ZnO and plastic deformation of the loaded crystal takes place. Enhanced hydrogen concentration detected in the subsurface region by NRA is, therefore, due to excess hydrogen trapped at open volume defects introduced by plastic deformation. Moreover, it was found that hydrogen-induced plastic deformation in the subsurface layer leads to typical surface modification: formation of hexagonal shape pyramids on the surface due to hydrogen-induced slip in the [0001] direction.

Impact of temperature and substrate concentration on degradation rates of acetate, propionate and hydrogen and their links to microbial community structure.

Science.gov (United States)

Zhao, Jing; Westerholm, Maria; Qiao, Wei; Yin, Dongmin; Bi, Shaojie; Jiang, Mengmeng; Dong, Renjie

2018-05-01

The present study investigates the conversion of acetate, propionate and hydrogen consumption linked to the microbial community structure and related to temperature and substrate concentration. Biogas reactors were continuously fed with coffee powder (20 g-COD/L) or acetate (20, 40, and 60 g-COD/L) and operated for 193 days at 37 °C or 55 °C conditions. Starting HRT was 23 days which was then reduced to 7 days. The kinetics of acetate and propionate degradation and hydrogen consumption rates were measured in batch assays. At HRT 7 days, the degradation rate of propionate was higher in thermophilic batches, while acetate degradation rate was higher at mesophilic conditions. The gaseous hydrogen consumption in acetate reactors increased proportionally with temperature and substrate concentration, while the dissolved hydrogen was not affected. The relative high abundance of hydrogentrophic methanogens indicated that the methanogenesis was directed towards the syntrophic acetate oxidation pathway at high acetate concentration and high temperature. Copyright © 2018 Elsevier Ltd. All rights reserved.

Determination of concentration and molar absorptivity of hypochlorous acid and hypobromous acid species by hydrogen peroxide titration

Science.gov (United States)

Uehara, H.; Arakaki, T.

2017-12-01

Hypochlorous acid and hypobromous acid (abbreviated as "HypoX acids") are the main ingredients of bleaching and bactericides. The HypoX acids change their chemical forms depending on environmental factors such as pH and various chemical reactions. For example, it has been reported that hypobromite ion in water changes to carcinogenic bromate by photochemical reaction with ultraviolet light. In this study, concentrations of HypoX acids were determined by UV-VIS absorbance measurement utilizing the fact that HypoX acids react with hydrogen peroxide and do not co-exist in the solution. The method for determining the concentration by titration with hydrogen peroxide can be carried out simpler and more efficiently than the DPD method or the current titration method generally used for chlorine concentration measurement. Molar absorptivity between 250 - 500 nm of HypoX acids, including their conjugate base species, was determined by solving theoretical acid-base formula including molar fraction of each chemical species at various pHs. Molar absorptivity of OCl- and OBr- between 250 - 500 nm was determined based on the concentrations obtained from titration with hydrogen peroxide and absorbance at pH > 10, where OCl- and OBr- dominate. Furthermore, the HypoX acids solutions were irradiated with a solar simulator, and the photolysis rate constants were obtained. Based on those values, the half-lives were calculated and the behavior of HypoX acids in the environment was elucidated.

Impact of hydrogen dilution on optical properties of intrinsic hydrogenated amorphous silicon films prepared by high density plasma chemical vapor deposition for solar cell applications

Science.gov (United States)

Chen, Huai-Yi; Lee, Yao-Jen; Chang, Chien-Pin; Koo, Horng-Show; Lai, Chiung-Hui

2013-01-01

P-i-n single-junction hydrogenated amorphous silicon (a-Si:H) thin film solar cells were successfully fabricated in this study on a glass substrate by high density plasma chemical vapor deposition (HDP-CVD) at low power of 50 W, low temperature of 200°C and various hydrogen dilution ratios (R). The open circuit voltage (Voc ), short circuit current density (Jsc ), fill factor (FF) and conversion efficiency (η) of the solar cell as well as the refractive index (n) and absorption coefficient (α) of the i-layer at 600 nm wavelength rise with increasing R until an abrupt drop at high hydrogen dilution, i.e. R > 0.95. However, the optical energy bandgap (Eg ) of the i-layer decreases with the R increase. Voc and α are inversely correlated with Eg . The hydrogen content affects the i-layer and p/i interface quality of the a-Si:H thin film solar cell with an optimal value of R = 0.95, which corresponds to solar cell conversion efficiency of 3.85%. The proposed a-Si:H thin film solar cell is expected to be improved in performance.

The influence of a spatial displacement of hydrogen on the reactivity and neutron flux density distribution in a ZrH-moderated reactor

International Nuclear Information System (INIS)

Doehler, J.; Bartsch, G.

1975-08-01

The effect of changes of the hydrogen concentration in uranium zirconium hydride resulting from spatially varying temperatures on the reactivity and neutron flux distribution of the BER-II core (power 2.2 MW) are shown. Furthermore, in general, the influence of the hydrogen concentration on important reactor parameters of a fuel cell of BER-II is calculated and presented. A comparison of the diffusion calculation with spatially constant hydrogen concentrations shows a decrease of the thermal neutron flux density in regions with a low hydrogen content (high temperature) and inversely an increase for high hydrogen concentrations. Furthermore, a change of the effective multiplication factor by 0.6% was found in the case of a spatially varying hydrogen concentration as compared with the calculation for a constant concentration. (orig.) [de

The hydrogen issue.

Science.gov (United States)

Armaroli, Nicola; Balzani, Vincenzo

2011-01-17

Hydrogen is often proposed as the fuel of the future, but the transformation from the present fossil fuel economy to a hydrogen economy will need the solution of numerous complex scientific and technological issues, which will require several decades to be accomplished. Hydrogen is not an alternative fuel, but an energy carrier that has to be produced by using energy, starting from hydrogen-rich compounds. Production from gasoline or natural gas does not offer any advantage over the direct use of such fuels. Production from coal by gasification techniques with capture and sequestration of CO₂ could be an interim solution. Water splitting by artificial photosynthesis, photobiological methods based on algae, and high temperatures obtained by nuclear or concentrated solar power plants are promising approaches, but still far from practical applications. In the next decades, the development of the hydrogen economy will most likely rely on water electrolysis by using enormous amounts of electric power, which in its turn has to be generated. Producing electricity by burning fossil fuels, of course, cannot be a rational solution. Hydroelectric power can give but a very modest contribution. Therefore, it will be necessary to generate large amounts of electric power by nuclear energy of by renewable energies. A hydrogen economy based on nuclear electricity would imply the construction of thousands of fission reactors, thereby magnifying all the problems related to the use of nuclear energy (e.g., safe disposal of radioactive waste, nuclear proliferation, plant decommissioning, uranium shortage). In principle, wind, photovoltaic, and concentrated solar power have the potential to produce enormous amounts of electric power, but, except for wind, such technologies are too underdeveloped and expensive to tackle such a big task in a short period of time. A full development of a hydrogen economy needs also improvement in hydrogen storage, transportation and distribution